include/scsi/libiscsi.h - linux - Git at Google

 /*
  * iSCSI lib definitions
  *
  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
  * Copyright (C) 2004 - 2006 Mike Christie
  * Copyright (C) 2004 - 2005 Dmitry Yusupov
  * Copyright (C) 2004 - 2005 Alex Aizman
  *
  * 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.
  */
 #ifndef LIBISCSI_H
 #define LIBISCSI_H

 #include <linux/types.h>
 #include <linux/wait.h>
 #include <linux/mutex.h>
 #include <linux/timer.h>
 #include <linux/workqueue.h>
 #include <scsi/iscsi_proto.h>
 #include <scsi/iscsi_if.h>

 struct scsi_transport_template;
 struct scsi_host_template;
 struct scsi_device;
 struct Scsi_Host;
 struct scsi_cmnd;
 struct socket;
 struct iscsi_transport;
 struct iscsi_cls_session;
 struct iscsi_cls_conn;
 struct iscsi_session;
 struct iscsi_nopin;
 struct device;

 /* #define DEBUG_SCSI */
 #ifdef DEBUG_SCSI
 #define debug_scsi(fmt...) printk(KERN_INFO "iscsi: " fmt)
 #else
 #define debug_scsi(fmt...)
 #endif

 #define ISCSI_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
 #define ISCSI_MGMT_CMDS_MAX	16	/* must be power of 2 */

 #define ISCSI_MGMT_ITT_OFFSET	0xa00

 #define ISCSI_DEF_CMD_PER_LUN		32
 #define ISCSI_MAX_CMD_PER_LUN		128

 /* Task Mgmt states */
 enum {
 	TMF_INITIAL,
 	TMF_QUEUED,
 	TMF_SUCCESS,
 	TMF_FAILED,
 	TMF_TIMEDOUT,
 	TMF_NOT_FOUND,
 };

 /* Connection suspend "bit" */
 #define ISCSI_SUSPEND_BIT		1

 #define ISCSI_ITT_MASK			(0xfff)
 #define ISCSI_AGE_SHIFT			28
 #define ISCSI_AGE_MASK			(0xf << ISCSI_AGE_SHIFT)

 #define ISCSI_ADDRESS_BUF_LEN		64

 enum {
 	/* this is the maximum possible storage for AHSs */
 	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
 				sizeof(struct iscsi_rlength_ahdr),
 	ISCSI_DIGEST_SIZE = sizeof(__u32),
 };


 enum {
 	ISCSI_TASK_COMPLETED,
 	ISCSI_TASK_PENDING,
 	ISCSI_TASK_RUNNING,
 };

 struct iscsi_task {
 	/*
 	 * Because LLDs allocate their hdr differently, this is a pointer
 	 * and length to that storage. It must be setup at session
 	 * creation time.
 	 */
 	struct iscsi_cmd	*hdr;
 	unsigned short		hdr_max;
 	unsigned short		hdr_len;	/* accumulated size of hdr used */
 	int			itt;		/* this ITT */

 	uint32_t		unsol_datasn;
 	unsigned		imm_count;	/* imm-data (bytes)   */
 	unsigned		unsol_count;	/* unsolicited (bytes)*/
 	/* offset in unsolicited stream (bytes); */
 	unsigned		unsol_offset;
 	unsigned		data_count;	/* remaining Data-Out */
 	char			*data;		/* mgmt payload */
 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
 	struct iscsi_conn	*conn;		/* used connection    */

 	/* state set/tested under session->lock */
 	int			state;
 	atomic_t		refcount;
 	struct list_head	running;	/* running cmd list */
 	void			*dd_data;	/* driver/transport data */
 };

 static inline void* iscsi_next_hdr(struct iscsi_task *task)
 {
 	return (void*)task->hdr + task->hdr_len;
 }

 /* Connection's states */
 enum {
 	ISCSI_CONN_INITIAL_STAGE,
 	ISCSI_CONN_STARTED,
 	ISCSI_CONN_STOPPED,
 	ISCSI_CONN_CLEANUP_WAIT,
 };

 struct iscsi_conn {
 	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
 	void			*dd_data;	/* iscsi_transport data */
 	struct iscsi_session	*session;	/* parent session */
 	/*
 	 * LLDs should set this lock. It protects the transport recv
 	 * code
 	 */
 	rwlock_t		*recv_lock;
 	/*
 	 * conn_stop() flag: stop to recover, stop to terminate
 	 */
         int			stop_stage;
 	struct timer_list	transport_timer;
 	unsigned long		last_recv;
 	unsigned long		last_ping;
 	int			ping_timeout;
 	int			recv_timeout;
 	struct iscsi_task 	*ping_task;

 	/* iSCSI connection-wide sequencing */
 	uint32_t		exp_statsn;

 	/* control data */
 	int			id;		/* CID */
 	int			c_stage;	/* connection state */
 	/*
 	 * Preallocated buffer for pdus that have data but do not
 	 * originate from scsi-ml. We never have two pdus using the
 	 * buffer at the same time. It is only allocated to
 	 * the default max recv size because the pdus we support
 	 * should always fit in this buffer
 	 */
 	char			*data;
 	struct iscsi_task 	*login_task;	/* mtask used for login/text */
 	struct iscsi_task	*task;		/* xmit task in progress */

 	/* xmit */
 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
 	struct list_head	mgmt_run_list;	/* list of control tasks */
 	struct list_head	xmitqueue;	/* data-path cmd queue */
 	struct list_head	run_list;	/* list of cmds in progress */
 	struct list_head	requeue;	/* tasks needing another run */
 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
 	unsigned long		suspend_tx;	/* suspend Tx */
 	unsigned long		suspend_rx;	/* suspend Rx */

 	/* abort */
 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
 	struct iscsi_tm		tmhdr;
 	struct timer_list	tmf_timer;
 	int			tmf_state;	/* see TMF_INITIAL, etc.*/

 	/* negotiated params */
 	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
 	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
 	int			hdrdgst_en;
 	int			datadgst_en;
 	int			ifmarker_en;
 	int			ofmarker_en;
 	/* values userspace uses to id a conn */
 	int			persistent_port;
 	char			*persistent_address;
 	/* remote portal currently connected to */
 	int			portal_port;
 	char			portal_address[ISCSI_ADDRESS_BUF_LEN];

 	/* MIB-statistics */
 	uint64_t		txdata_octets;
 	uint64_t		rxdata_octets;
 	uint32_t		scsicmd_pdus_cnt;
 	uint32_t		dataout_pdus_cnt;
 	uint32_t		scsirsp_pdus_cnt;
 	uint32_t		datain_pdus_cnt;
 	uint32_t		r2t_pdus_cnt;
 	uint32_t		tmfcmd_pdus_cnt;
 	int32_t			tmfrsp_pdus_cnt;

 	/* custom statistics */
 	uint32_t		eh_abort_cnt;
 	uint32_t		fmr_unalign_cnt;
 };

 struct iscsi_pool {
 	struct kfifo		*queue;		/* FIFO Queue */
 	void			**pool;		/* Pool of elements */
 	int			max;		/* Max number of elements */
 };

 /* Session's states */
 enum {
 	ISCSI_STATE_FREE = 1,
 	ISCSI_STATE_LOGGED_IN,
 	ISCSI_STATE_FAILED,
 	ISCSI_STATE_TERMINATE,
 	ISCSI_STATE_IN_RECOVERY,
 	ISCSI_STATE_RECOVERY_FAILED,
 	ISCSI_STATE_LOGGING_OUT,
 };

 struct iscsi_session {
 	struct iscsi_cls_session *cls_session;
 	/*
 	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
 	 * task management functions. This must be taken before the session
 	 * and recv lock.
 	 */
 	struct mutex		eh_mutex;

 	/* iSCSI session-wide sequencing */
 	uint32_t		cmdsn;
 	uint32_t		exp_cmdsn;
 	uint32_t		max_cmdsn;

 	/* This tracks the reqs queued into the initiator */
 	uint32_t		queued_cmdsn;

 	/* configuration */
 	int			abort_timeout;
 	int			lu_reset_timeout;
 	int			initial_r2t_en;
 	unsigned		max_r2t;
 	int			imm_data_en;
 	unsigned		first_burst;
 	unsigned		max_burst;
 	int			time2wait;
 	int			time2retain;
 	int			pdu_inorder_en;
 	int			dataseq_inorder_en;
 	int			erl;
 	int			fast_abort;
 	int			tpgt;
 	char			*username;
 	char			*username_in;
 	char			*password;
 	char			*password_in;
 	char			*targetname;
 	char			*ifacename;
 	char			*initiatorname;
 	/* control data */
 	struct iscsi_transport	*tt;
 	struct Scsi_Host	*host;
 	struct iscsi_conn	*leadconn;	/* leading connection */
 	spinlock_t		lock;		/* protects session state, *
 						 * sequence numbers,       *
 						 * session resources:      *
 						 * - cmdpool,		   *
 						 * - mgmtpool,		   *
 						 * - r2tpool		   */
 	int			state;		/* session state           */
 	int			age;		/* counts session re-opens */

 	int			scsi_cmds_max; 	/* max scsi commands */
 	int			cmds_max;	/* size of cmds array */
 	struct iscsi_task	**cmds;		/* Original Cmds arr */
 	struct iscsi_pool	cmdpool;	/* PDU's pool */
 };

 struct iscsi_host {
 	char			*initiatorname;
 	/* hw address or netdev iscsi connection is bound to */
 	char			*hwaddress;
 	char			*netdev;
 	/* local address */
 	int			local_port;
 	char			local_address[ISCSI_ADDRESS_BUF_LEN];
 };

 /*
  * scsi host template
  */
 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 extern int iscsi_eh_host_reset(struct scsi_cmnd *sc);
 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
 			      void (*done)(struct scsi_cmnd *));

 /*
  * iSCSI host helpers.
  */
 #define iscsi_host_priv(_shost) \
 	(shost_priv(_shost) + sizeof(struct iscsi_host))

 extern int iscsi_host_set_param(struct Scsi_Host *shost,
 				enum iscsi_host_param param, char *buf,
 				int buflen);
 extern int iscsi_host_get_param(struct Scsi_Host *shost,
 				enum iscsi_host_param param, char *buf);
 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 					  int dd_data_size, uint16_t qdepth);
 extern void iscsi_host_remove(struct Scsi_Host *shost);
 extern void iscsi_host_free(struct Scsi_Host *shost);

 /*
  * session management
  */
 extern struct iscsi_cls_session *
 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 		    uint16_t, int, uint32_t, unsigned int);
 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 			   enum iscsi_param param, char *buf, int buflen);
 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 				   enum iscsi_param param, char *buf);

 #define iscsi_session_printk(prefix, _sess, fmt, a...)	\
 	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)

 /*
  * connection management
  */
 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 					       int, uint32_t);
 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 extern int iscsi_conn_start(struct iscsi_cls_conn *);
 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 			   int);
 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 				enum iscsi_param param, char *buf);
 extern void iscsi_suspend_tx(struct iscsi_conn *conn);

 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
 	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
 			      fmt, ##a)

 /*
  * pdu and task processing
  */
 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_task *,
 					struct iscsi_data *hdr);
 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 				char *, uint32_t);
 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 			      char *, int);
 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 extern void iscsi_requeue_task(struct iscsi_task *task);
 extern void iscsi_put_task(struct iscsi_task *task);

 /*
  * generic helpers
  */
 extern void iscsi_pool_free(struct iscsi_pool *);
 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);

 /*
  * inline functions to deal with padding.
  */
 static inline unsigned int
 iscsi_padded(unsigned int len)
 {
 	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 }

 static inline unsigned int
 iscsi_padding(unsigned int len)
 {
 	len &= (ISCSI_PAD_LEN - 1);
 	if (len)
 		len = ISCSI_PAD_LEN - len;
 	return len;
 }

 #endif
	/*
	* iSCSI lib definitions
	*
	* Copyright (C) 2006 Red Hat, Inc. All rights reserved.
	* Copyright (C) 2004 - 2006 Mike Christie
	* Copyright (C) 2004 - 2005 Dmitry Yusupov
	* Copyright (C) 2004 - 2005 Alex Aizman
	*
	* 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.
	*/
	#ifndef LIBISCSI_H
	#define LIBISCSI_H

	#include <linux/types.h>
	#include <linux/wait.h>
	#include <linux/mutex.h>
	#include <linux/timer.h>
	#include <linux/workqueue.h>
	#include <scsi/iscsi_proto.h>
	#include <scsi/iscsi_if.h>

	struct scsi_transport_template;
	struct scsi_host_template;
	struct scsi_device;
	struct Scsi_Host;
	struct scsi_cmnd;
	struct socket;
	struct iscsi_transport;
	struct iscsi_cls_session;
	struct iscsi_cls_conn;
	struct iscsi_session;
	struct iscsi_nopin;
	struct device;

	/* #define DEBUG_SCSI */
	#ifdef DEBUG_SCSI
	#define debug_scsi(fmt...) printk(KERN_INFO "iscsi: " fmt)
	#else
	#define debug_scsi(fmt...)
	#endif

	#define ISCSI_DEF_XMIT_CMDS_MAX 128 /* must be power of 2 */
	#define ISCSI_MGMT_CMDS_MAX 16 /* must be power of 2 */

	#define ISCSI_MGMT_ITT_OFFSET 0xa00

	#define ISCSI_DEF_CMD_PER_LUN 32
	#define ISCSI_MAX_CMD_PER_LUN 128

	/* Task Mgmt states */
	enum {
	TMF_INITIAL,
	TMF_QUEUED,
	TMF_SUCCESS,
	TMF_FAILED,
	TMF_TIMEDOUT,
	TMF_NOT_FOUND,
	};

	/* Connection suspend "bit" */
	#define ISCSI_SUSPEND_BIT 1

	#define ISCSI_ITT_MASK (0xfff)
	#define ISCSI_AGE_SHIFT 28
	#define ISCSI_AGE_MASK (0xf << ISCSI_AGE_SHIFT)

	#define ISCSI_ADDRESS_BUF_LEN 64

	enum {
	/* this is the maximum possible storage for AHSs */
	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
	sizeof(struct iscsi_rlength_ahdr),
	ISCSI_DIGEST_SIZE = sizeof(__u32),
	};


	enum {
	ISCSI_TASK_COMPLETED,
	ISCSI_TASK_PENDING,
	ISCSI_TASK_RUNNING,
	};

	struct iscsi_task {
	/*
	* Because LLDs allocate their hdr differently, this is a pointer
	* and length to that storage. It must be setup at session
	* creation time.
	*/
	struct iscsi_cmd *hdr;
	unsigned short hdr_max;
	unsigned short hdr_len; /* accumulated size of hdr used */
	int itt; /* this ITT */

	uint32_t unsol_datasn;
	unsigned imm_count; /* imm-data (bytes) */
	unsigned unsol_count; /* unsolicited (bytes)*/
	/* offset in unsolicited stream (bytes); */
	unsigned unsol_offset;
	unsigned data_count; /* remaining Data-Out */
	char data; / mgmt payload */
	struct scsi_cmnd sc; / associated SCSI cmd*/
	struct iscsi_conn conn; / used connection */

	/* state set/tested under session->lock */
	int state;
	atomic_t refcount;
	struct list_head running; /* running cmd list */
	void dd_data; / driver/transport data */
	};

	static inline void* iscsi_next_hdr(struct iscsi_task *task)
	{
	return (void*)task->hdr + task->hdr_len;
	}

	/* Connection's states */
	enum {
	ISCSI_CONN_INITIAL_STAGE,
	ISCSI_CONN_STARTED,
	ISCSI_CONN_STOPPED,
	ISCSI_CONN_CLEANUP_WAIT,
	};

	struct iscsi_conn {
	struct iscsi_cls_conn cls_conn; / ptr to class connection */
	void dd_data; / iscsi_transport data */
	struct iscsi_session session; / parent session */
	/*
	* LLDs should set this lock. It protects the transport recv
	* code
	*/
	rwlock_t *recv_lock;
	/*
	* conn_stop() flag: stop to recover, stop to terminate
	*/
	int stop_stage;
	struct timer_list transport_timer;
	unsigned long last_recv;
	unsigned long last_ping;
	int ping_timeout;
	int recv_timeout;
	struct iscsi_task *ping_task;

	/* iSCSI connection-wide sequencing */
	uint32_t exp_statsn;

	/* control data */
	int id; /* CID */
	int c_stage; /* connection state */
	/*
	* Preallocated buffer for pdus that have data but do not
	* originate from scsi-ml. We never have two pdus using the
	* buffer at the same time. It is only allocated to
	* the default max recv size because the pdus we support
	* should always fit in this buffer
	*/
	char *data;
	struct iscsi_task login_task; / mtask used for login/text */
	struct iscsi_task task; / xmit task in progress */

	/* xmit */
	struct list_head mgmtqueue; /* mgmt (control) xmit queue */
	struct list_head mgmt_run_list; /* list of control tasks */
	struct list_head xmitqueue; /* data-path cmd queue */
	struct list_head run_list; /* list of cmds in progress */
	struct list_head requeue; /* tasks needing another run */
	struct work_struct xmitwork; /* per-conn. xmit workqueue */
	unsigned long suspend_tx; /* suspend Tx */
	unsigned long suspend_rx; /* suspend Rx */

	/* abort */
	wait_queue_head_t ehwait; /* used in eh_abort() */
	struct iscsi_tm tmhdr;
	struct timer_list tmf_timer;
	int tmf_state; /* see TMF_INITIAL, etc.*/

	/* negotiated params */
	unsigned max_recv_dlength; /* initiator_max_recv_dsl*/
	unsigned max_xmit_dlength; /* target_max_recv_dsl */
	int hdrdgst_en;
	int datadgst_en;
	int ifmarker_en;
	int ofmarker_en;
	/* values userspace uses to id a conn */
	int persistent_port;
	char *persistent_address;
	/* remote portal currently connected to */
	int portal_port;
	char portal_address[ISCSI_ADDRESS_BUF_LEN];

	/* MIB-statistics */
	uint64_t txdata_octets;
	uint64_t rxdata_octets;
	uint32_t scsicmd_pdus_cnt;
	uint32_t dataout_pdus_cnt;
	uint32_t scsirsp_pdus_cnt;
	uint32_t datain_pdus_cnt;
	uint32_t r2t_pdus_cnt;
	uint32_t tmfcmd_pdus_cnt;
	int32_t tmfrsp_pdus_cnt;

	/* custom statistics */
	uint32_t eh_abort_cnt;
	uint32_t fmr_unalign_cnt;
	};

	struct iscsi_pool {
	struct kfifo queue; / FIFO Queue */
	void *pool; / Pool of elements */
	int max; /* Max number of elements */
	};

	/* Session's states */
	enum {
	ISCSI_STATE_FREE = 1,
	ISCSI_STATE_LOGGED_IN,
	ISCSI_STATE_FAILED,
	ISCSI_STATE_TERMINATE,
	ISCSI_STATE_IN_RECOVERY,
	ISCSI_STATE_RECOVERY_FAILED,
	ISCSI_STATE_LOGGING_OUT,
	};

	struct iscsi_session {
	struct iscsi_cls_session *cls_session;
	/*
	* Syncs up the scsi eh thread with the iscsi eh thread when sending
	* task management functions. This must be taken before the session
	* and recv lock.
	*/
	struct mutex eh_mutex;

	/* iSCSI session-wide sequencing */
	uint32_t cmdsn;
	uint32_t exp_cmdsn;
	uint32_t max_cmdsn;

	/* This tracks the reqs queued into the initiator */
	uint32_t queued_cmdsn;

	/* configuration */
	int abort_timeout;
	int lu_reset_timeout;
	int initial_r2t_en;
	unsigned max_r2t;
	int imm_data_en;
	unsigned first_burst;
	unsigned max_burst;
	int time2wait;
	int time2retain;
	int pdu_inorder_en;
	int dataseq_inorder_en;
	int erl;
	int fast_abort;
	int tpgt;
	char *username;
	char *username_in;
	char *password;
	char *password_in;
	char *targetname;
	char *ifacename;
	char *initiatorname;
	/* control data */
	struct iscsi_transport *tt;
	struct Scsi_Host *host;
	struct iscsi_conn leadconn; / leading connection */
	spinlock_t lock; /* protects session state, *
	* sequence numbers, *
	* session resources: *
	* - cmdpool, *
	* - mgmtpool, *
	* - r2tpool */
	int state; /* session state */
	int age; /* counts session re-opens */

	int scsi_cmds_max; /* max scsi commands */
	int cmds_max; /* size of cmds array */
	struct iscsi_task *cmds; / Original Cmds arr */
	struct iscsi_pool cmdpool; /* PDU's pool */
	};

	struct iscsi_host {
	char *initiatorname;
	/* hw address or netdev iscsi connection is bound to */
	char *hwaddress;
	char *netdev;
	/* local address */
	int local_port;
	char local_address[ISCSI_ADDRESS_BUF_LEN];
	};

	/*
	* scsi host template
	*/
	extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
	extern int iscsi_eh_abort(struct scsi_cmnd *sc);
	extern int iscsi_eh_host_reset(struct scsi_cmnd *sc);
	extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
	extern int iscsi_queuecommand(struct scsi_cmnd *sc,
	void (done)(struct scsi_cmnd ));

	/*
	* iSCSI host helpers.
	*/
	#define iscsi_host_priv(_shost) \
	(shost_priv(_shost) + sizeof(struct iscsi_host))

	extern int iscsi_host_set_param(struct Scsi_Host *shost,
	enum iscsi_host_param param, char *buf,
	int buflen);
	extern int iscsi_host_get_param(struct Scsi_Host *shost,
	enum iscsi_host_param param, char *buf);
	extern int iscsi_host_add(struct Scsi_Host shost, struct device pdev);
	extern struct Scsi_Host iscsi_host_alloc(struct scsi_host_template sht,
	int dd_data_size, uint16_t qdepth);
	extern void iscsi_host_remove(struct Scsi_Host *shost);
	extern void iscsi_host_free(struct Scsi_Host *shost);

	/*
	* session management
	*/
	extern struct iscsi_cls_session *
	iscsi_session_setup(struct iscsi_transport , struct Scsi_Host shost,
	uint16_t, int, uint32_t, unsigned int);
	extern void iscsi_session_teardown(struct iscsi_cls_session *);
	extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
	extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
	enum iscsi_param param, char *buf, int buflen);
	extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
	enum iscsi_param param, char *buf);

	#define iscsi_session_printk(prefix, _sess, fmt, a...) \
	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)

	/*
	* connection management
	*/
	extern struct iscsi_cls_conn iscsi_conn_setup(struct iscsi_cls_session ,
	int, uint32_t);
	extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
	extern int iscsi_conn_start(struct iscsi_cls_conn *);
	extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
	extern int iscsi_conn_bind(struct iscsi_cls_session , struct iscsi_cls_conn ,
	int);
	extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
	extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
	enum iscsi_param param, char *buf);
	extern void iscsi_suspend_tx(struct iscsi_conn *conn);

	#define iscsi_conn_printk(prefix, _c, fmt, a...) \
	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
	fmt, ##a)

	/*
	* pdu and task processing
	*/
	extern void iscsi_update_cmdsn(struct iscsi_session , struct iscsi_nopin );
	extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_task *,
	struct iscsi_data *hdr);
	extern int iscsi_conn_send_pdu(struct iscsi_cls_conn , struct iscsi_hdr ,
	char *, uint32_t);
	extern int iscsi_complete_pdu(struct iscsi_conn , struct iscsi_hdr ,
	char *, int);
	extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
	extern struct iscsi_task iscsi_itt_to_ctask(struct iscsi_conn , itt_t);
	extern void iscsi_requeue_task(struct iscsi_task *task);
	extern void iscsi_put_task(struct iscsi_task *task);

	/*
	* generic helpers
	*/
	extern void iscsi_pool_free(struct iscsi_pool *);
	extern int iscsi_pool_init(struct iscsi_pool , int, void **, int);

	/*
	* inline functions to deal with padding.
	*/
	static inline unsigned int
	iscsi_padded(unsigned int len)
	{
	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
	}

	static inline unsigned int
	iscsi_padding(unsigned int len)
	{
	len &= (ISCSI_PAD_LEN - 1);
	if (len)
	len = ISCSI_PAD_LEN - len;
	return len;
	}

	#endif