[mirror_ubuntu-bionic-kernel.git] / drivers / scsi / iscsi_tcp.h

/*
 * iSCSI Initiator TCP Transport
 * Copyright (C) 2004 Dmitry Yusupov
 * Copyright (C) 2004 Alex Aizman
 * Copyright (C) 2005 Mike Christie
 * maintained by open-iscsi@googlegroups.com
 *
 * 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.
 *
 * See the file COPYING included with this distribution for more details.
 */

#ifndef ISCSI_TCP_H
#define ISCSI_TCP_H

/* Session's states */
#define ISCSI_STATE_FREE		1
#define ISCSI_STATE_LOGGED_IN		2
#define ISCSI_STATE_FAILED		3
#define ISCSI_STATE_TERMINATE		4

/* Connection's states */
#define ISCSI_CONN_INITIAL_STAGE	0
#define ISCSI_CONN_STARTED		1
#define ISCSI_CONN_STOPPED		2
#define ISCSI_CONN_CLEANUP_WAIT		3

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

/* Socket's Receive state machine */
#define IN_PROGRESS_WAIT_HEADER		0x0
#define IN_PROGRESS_HEADER_GATHER	0x1
#define IN_PROGRESS_DATA_RECV		0x2
#define IN_PROGRESS_DDIGEST_RECV	0x3

/* Task Mgmt states */
#define	TMABORT_INITIAL			0x0
#define	TMABORT_SUCCESS			0x1
#define	TMABORT_FAILED			0x2
#define	TMABORT_TIMEDOUT		0x3

/* xmit state machine */
#define	XMSTATE_IDLE			0x0
#define	XMSTATE_R_HDR			0x1
#define	XMSTATE_W_HDR			0x2
#define	XMSTATE_IMM_HDR			0x4
#define	XMSTATE_IMM_DATA		0x8
#define	XMSTATE_UNS_INIT		0x10
#define	XMSTATE_UNS_HDR			0x20
#define	XMSTATE_UNS_DATA		0x40
#define	XMSTATE_SOL_HDR			0x80
#define	XMSTATE_SOL_DATA		0x100
#define	XMSTATE_W_PAD			0x200
#define XMSTATE_DATA_DIGEST		0x400

#define ISCSI_CONN_MAX			1
#define ISCSI_CONN_RCVBUF_MIN		262144
#define ISCSI_CONN_SNDBUF_MIN		262144
#define ISCSI_PAD_LEN			4
#define ISCSI_R2T_MAX			16
#define ISCSI_XMIT_CMDS_MAX		128	/* must be power of 2 */
#define ISCSI_MGMT_CMDS_MAX		32	/* must be power of 2 */
#define ISCSI_MGMT_ITT_OFFSET		0xa00
#define ISCSI_SG_TABLESIZE		SG_ALL
#define ISCSI_DEF_CMD_PER_LUN		32
#define ISCSI_MAX_CMD_PER_LUN		128
#define ISCSI_TCP_MAX_CMD_LEN		16

#define ITT_MASK			(0xfff)
#define CID_SHIFT			12
#define CID_MASK			(0xffff<<CID_SHIFT)
#define AGE_SHIFT			28
#define AGE_MASK			(0xf<<AGE_SHIFT)

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

struct iscsi_session;
struct iscsi_cmd_task;
struct iscsi_mgmt_task;

/* Socket connection recieve helper */
struct iscsi_tcp_recv {
	struct iscsi_hdr	*hdr;
	struct sk_buff		*skb;
	int			offset;
	int			len;
	int			hdr_offset;
	int			copy;
	int			copied;
	int			padding;
	struct iscsi_cmd_task	*ctask;		/* current cmd in progress */

	/* copied and flipped values */
	int			opcode;
	int			flags;
	int			cmd_status;
	int			ahslen;
	int			datalen;
	uint32_t		itt;
	int			datadgst;
};

struct iscsi_conn {
	struct iscsi_hdr	hdr;		/* header placeholder */
	char			hdrext[4*sizeof(__u16) +
				    sizeof(__u32)];
	int			data_copied;
	char			*data;		/* data placeholder */
	struct socket           *sock;          /* TCP socket */
	int			data_size;	/* actual recv_dlength */
	int			stop_stage;	/* conn_stop() flag: *
						 * stop to recover,  *
						 * stop to terminate */
	/* iSCSI connection-wide sequencing */
	uint32_t		exp_statsn;
	int			hdr_size;	/* PDU header size */
	unsigned long		suspend_rx;	/* suspend Rx */

	struct crypto_tfm	*rx_tfm;	/* CRC32C (Rx) */
	struct crypto_tfm	*data_rx_tfm;	/* CRC32C (Rx) for data */

	/* control data */
	int			senselen;	/* scsi sense length */
	int			id;		/* CID */
	struct iscsi_tcp_recv	in;		/* TCP receive context */
	struct iscsi_session	*session;	/* parent session */
	struct list_head	item;		/* maintains list of conns */
	int			in_progress;	/* connection state machine */
	int			c_stage;	/* connection state */
	struct iscsi_mgmt_task	*login_mtask;	/* mtask used for login/text */
	struct iscsi_mgmt_task	*mtask;		/* xmit mtask in progress */
	struct iscsi_cmd_task	*ctask;		/* xmit ctask in progress */
	spinlock_t		lock;		/* FIXME: to be removed */

	/* old values for socket callbacks */
	void			(*old_data_ready)(struct sock *, int);
	void			(*old_state_change)(struct sock *);
	void			(*old_write_space)(struct sock *);

	/* xmit */
	struct crypto_tfm	*tx_tfm;	/* CRC32C (Tx) */
	struct crypto_tfm	*data_tx_tfm;	/* CRC32C (Tx) for data */
	struct kfifo		*writequeue;	/* write cmds for Data-Outs */
	struct kfifo		*immqueue;	/* immediate xmit queue */
	struct kfifo		*mgmtqueue;	/* mgmt (control) xmit queue */
	struct kfifo		*xmitqueue;	/* data-path cmd queue */
	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
	struct mutex		xmitmutex;	/* serializes connection xmit,
						 * access to kfifos:	  *
						 * xmitqueue, writequeue, *
						 * immqueue, mgmtqueue    */
	unsigned long		suspend_tx;	/* suspend Tx */

	/* abort */
	wait_queue_head_t	ehwait;		/* used in eh_abort()     */
	struct iscsi_tm		tmhdr;
	struct timer_list	tmabort_timer;  /* abort timer */
	int			tmabort_state;  /* see TMABORT_INITIAL, etc.*/

	/* negotiated params */
	int			max_recv_dlength;
	int			max_xmit_dlength;
	int			hdrdgst_en;
	int			datadgst_en;

	/* 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		sendpage_failures_cnt;
	uint32_t		discontiguous_hdr_cnt;
	uint32_t		eh_abort_cnt;
};

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

	/* configuration */
	int			initial_r2t_en;
	int			max_r2t;
	int			imm_data_en;
	int			first_burst;
	int			max_burst;
	int			time2wait;
	int			time2retain;
	int			pdu_inorder_en;
	int			dataseq_inorder_en;
	int			erl;
	int			ifmarker_en;
	int			ofmarker_en;

	/* control data */
	struct Scsi_Host	*host;
	int			id;
	struct iscsi_conn	*leadconn;	/* leading connection */
	spinlock_t		lock;		/* protects session state, *
						 * sequence numbers,       *
						 * session resources:      *
						 * - cmdpool,		   *
						 * - mgmtpool,		   *
						 * - r2tpool		   */
	int			state;		/* session state           */
	struct list_head	item;
	void			*auth_client;
	int			conn_cnt;
	int			age;		/* counts session re-opens */

	struct list_head	connections;	/* list of connections */
	int			cmds_max;	/* size of cmds array */
	struct iscsi_cmd_task	**cmds;		/* Original Cmds arr */
	struct iscsi_queue	cmdpool;	/* PDU's pool */
	int			mgmtpool_max;	/* size of mgmt array */
	struct iscsi_mgmt_task	**mgmt_cmds;	/* Original mgmt arr */
	struct iscsi_queue	mgmtpool;	/* Mgmt PDU's pool */
};

struct iscsi_buf {
	struct scatterlist	sg;
	struct kvec		iov;
	unsigned int		sent;
};

struct iscsi_data_task {
	struct iscsi_data	hdr;			/* PDU */
	char			hdrext[sizeof(__u32)];	/* Header-Digest */
	struct list_head	item;			/* data queue item */
	struct iscsi_buf	digestbuf;		/* digest buffer */
	uint32_t		digest;			/* data digest */
};
#define ISCSI_DTASK_DEFAULT_MAX	ISCSI_SG_TABLESIZE * PAGE_SIZE / 512

struct iscsi_mgmt_task {
	struct iscsi_hdr	hdr;		/* mgmt. PDU */
	char			hdrext[sizeof(__u32)];	/* Header-Digest */
	char			*data;		/* mgmt payload */
	int			xmstate;	/* mgmt xmit progress */
	int			data_count;	/* counts data to be sent */
	struct iscsi_buf	headbuf;	/* header buffer */
	struct iscsi_buf	sendbuf;	/* in progress buffer */
	int			sent;
	uint32_t		itt;		/* this ITT */
};

struct iscsi_r2t_info {
	__be32			ttt;		/* copied from R2T */
	__be32			exp_statsn;	/* copied from R2T */
	uint32_t		data_length;	/* copied from R2T */
	uint32_t		data_offset;	/* copied from R2T */
	struct iscsi_buf	headbuf;	/* Data-Out Header Buffer */
	struct iscsi_buf	sendbuf;	/* Data-Out in progress buffer*/
	int			sent;		/* R2T sequence progress */
	int			data_count;	/* DATA-Out payload progress */
	struct scatterlist	*sg;		/* per-R2T SG list */
	int			solicit_datasn;
	struct iscsi_data_task   *dtask;        /* which data task */
};

struct iscsi_cmd_task {
	struct iscsi_cmd	hdr;			/* iSCSI PDU header */
	char			hdrext[4*sizeof(__u16)+	/* AHS */
				    sizeof(__u32)];	/* HeaderDigest */
	char			pad[ISCSI_PAD_LEN];
	int			itt;			/* this ITT */
	int			datasn;			/* DataSN */
	struct iscsi_buf	headbuf;		/* header buf (xmit) */
	struct iscsi_buf	sendbuf;		/* in progress buffer*/
	int			sent;
	struct scatterlist	*sg;			/* per-cmd SG list  */
	struct scatterlist	*bad_sg;		/* assert statement */
	int			sg_count;		/* SG's to process  */
	uint32_t		unsol_datasn;
	uint32_t		exp_r2tsn;
	int			xmstate;		/* xmit xtate machine */
	int			imm_count;		/* imm-data (bytes)   */
	int			unsol_count;		/* unsolicited (bytes)*/
	int			r2t_data_count;		/* R2T Data-Out bytes */
	int			data_count;		/* remaining Data-Out */
	int			pad_count;		/* padded bytes */
	struct scsi_cmnd	*sc;			/* associated SCSI cmd*/
	int			total_length;
	int			data_offset;
	struct iscsi_conn	*conn;			/* used connection    */
	struct iscsi_mgmt_task	*mtask;			/* tmf mtask in progr */

	struct iscsi_r2t_info	*r2t;			/* in progress R2T    */
	struct iscsi_queue	r2tpool;
	struct kfifo		*r2tqueue;
	struct iscsi_r2t_info	**r2ts;
	struct list_head	dataqueue;		/* Data-Out dataqueue */
	mempool_t		*datapool;
	uint32_t		datadigest;		/* for recover digest */
	int			digest_count;
	uint32_t		immdigest;		/* for imm data */
	struct iscsi_buf	immbuf;			/* for imm data digest */
	struct iscsi_data_task   *dtask;		/* data task in progress*/
	int			digest_offset;		/* for partial buff digest */
};

#endif /* ISCSI_H */
Commit	Line	Data
c213ca07 AA	1	/*
	2	* iSCSI Initiator TCP Transport
	3	* Copyright (C) 2004 Dmitry Yusupov
	4	* Copyright (C) 2004 Alex Aizman
	5	* Copyright (C) 2005 Mike Christie
	6	* maintained by open-iscsi@googlegroups.com
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published
	10	* by the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful, but
	14	* WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* General Public License for more details.
	17	*
	18	* See the file COPYING included with this distribution for more details.
	19	*/
	20
	21	#ifndef ISCSI_TCP_H
	22	#define ISCSI_TCP_H
	23
	24	/* Session's states */
	25	#define ISCSI_STATE_FREE 1
	26	#define ISCSI_STATE_LOGGED_IN 2
	27	#define ISCSI_STATE_FAILED 3
	28	#define ISCSI_STATE_TERMINATE 4
	29
	30	/* Connection's states */
	31	#define ISCSI_CONN_INITIAL_STAGE 0
	32	#define ISCSI_CONN_STARTED 1
	33	#define ISCSI_CONN_STOPPED 2
	34	#define ISCSI_CONN_CLEANUP_WAIT 3
	35
	36	/* Connection suspend "bit" */
	37	#define SUSPEND_BIT 1
	38
	39	/* Socket's Receive state machine */
	40	#define IN_PROGRESS_WAIT_HEADER 0x0
	41	#define IN_PROGRESS_HEADER_GATHER 0x1
	42	#define IN_PROGRESS_DATA_RECV 0x2
	43	#define IN_PROGRESS_DDIGEST_RECV 0x3
	44
	45	/* Task Mgmt states */
	46	#define TMABORT_INITIAL 0x0
	47	#define TMABORT_SUCCESS 0x1
	48	#define TMABORT_FAILED 0x2
	49	#define TMABORT_TIMEDOUT 0x3
	50
	51	/* xmit state machine */
	52	#define XMSTATE_IDLE 0x0
	53	#define XMSTATE_R_HDR 0x1
	54	#define XMSTATE_W_HDR 0x2
	55	#define XMSTATE_IMM_HDR 0x4
	56	#define XMSTATE_IMM_DATA 0x8
	57	#define XMSTATE_UNS_INIT 0x10
	58	#define XMSTATE_UNS_HDR 0x20
	59	#define XMSTATE_UNS_DATA 0x40
	60	#define XMSTATE_SOL_HDR 0x80
	61	#define XMSTATE_SOL_DATA 0x100
	62	#define XMSTATE_W_PAD 0x200
	63	#define XMSTATE_DATA_DIGEST 0x400
	64
65	#define ISCSI_CONN_MAX 1
66	#define ISCSI_CONN_RCVBUF_MIN 262144
67	#define ISCSI_CONN_SNDBUF_MIN 262144
68	#define ISCSI_PAD_LEN 4
69	#define ISCSI_R2T_MAX 16
70	#define ISCSI_XMIT_CMDS_MAX 128 /* must be power of 2 */
71	#define ISCSI_MGMT_CMDS_MAX 32 /* must be power of 2 */
72	#define ISCSI_MGMT_ITT_OFFSET 0xa00
73	#define ISCSI_SG_TABLESIZE SG_ALL
9e3961ba MC	74	#define ISCSI_DEF_CMD_PER_LUN 32
9e3961ba MC	75	#define ISCSI_MAX_CMD_PER_LUN 128
c213ca07 AA	76	#define ISCSI_TCP_MAX_CMD_LEN 16
	77
	78	#define ITT_MASK (0xfff)
	79	#define CID_SHIFT 12
	80	#define CID_MASK (0xffff<<CID_SHIFT)
	81	#define AGE_SHIFT 28
	82	#define AGE_MASK (0xf<<AGE_SHIFT)
	83
	84	struct iscsi_queue {
	85	struct kfifo queue; / FIFO Queue */
	86	void *pool; / Pool of elements */
	87	int max; /* Max number of elements */
	88	};
	89
	90	struct iscsi_session;
	91	struct iscsi_cmd_task;
	92	struct iscsi_mgmt_task;
	93
	94	/* Socket connection recieve helper */
	95	struct iscsi_tcp_recv {
	96	struct iscsi_hdr *hdr;
	97	struct sk_buff *skb;
	98	int offset;
	99	int len;
	100	int hdr_offset;
	101	int copy;
	102	int copied;
	103	int padding;
	104	struct iscsi_cmd_task ctask; / current cmd in progress */
	105
	106	/* copied and flipped values */
	107	int opcode;
	108	int flags;
	109	int cmd_status;
	110	int ahslen;
	111	int datalen;
	112	uint32_t itt;
	113	int datadgst;
	114	};
	115
	116	struct iscsi_conn {
	117	struct iscsi_hdr hdr; /* header placeholder */
	118	char hdrext[4*sizeof(__u16) +
	119	sizeof(__u32)];
	120	int data_copied;
	121	char data; / data placeholder */
	122	struct socket sock; / TCP socket */
	123	int data_size; /* actual recv_dlength */
	124	int stop_stage; /* conn_stop() flag: *
	125	* stop to recover, *
	126	* stop to terminate */
	127	/* iSCSI connection-wide sequencing */
	128	uint32_t exp_statsn;
	129	int hdr_size; /* PDU header size */
	130	unsigned long suspend_rx; /* suspend Rx */
	131
	132	struct crypto_tfm rx_tfm; / CRC32C (Rx) */
	133	struct crypto_tfm data_rx_tfm; / CRC32C (Rx) for data */
	134
	135	/* control data */
	136	int senselen; /* scsi sense length */
	137	int id; /* CID */
	138	struct iscsi_tcp_recv in; /* TCP receive context */
	139	struct iscsi_session session; / parent session */
140	struct list_head item; /* maintains list of conns */
141	int in_progress; /* connection state machine */
142	int c_stage; /* connection state */
143	struct iscsi_mgmt_task login_mtask; / mtask used for login/text */
144	struct iscsi_mgmt_task mtask; / xmit mtask in progress */
145	struct iscsi_cmd_task ctask; / xmit ctask in progress */
146	spinlock_t lock; /* FIXME: to be removed */
147
148	/* old values for socket callbacks */
149	void (old_data_ready)(struct sock , int);
150	void (old_state_change)(struct sock );
151	void (old_write_space)(struct sock );
152
153	/* xmit */
154	struct crypto_tfm tx_tfm; / CRC32C (Tx) */
155	struct crypto_tfm data_tx_tfm; / CRC32C (Tx) for data */
156	struct kfifo writequeue; / write cmds for Data-Outs */
157	struct kfifo immqueue; / immediate xmit queue */
158	struct kfifo mgmtqueue; / mgmt (control) xmit queue */
159	struct kfifo xmitqueue; / data-path cmd queue */
160	struct work_struct xmitwork; /* per-conn. xmit workqueue */
0b950672	161	struct mutex xmitmutex; /* serializes connection xmit,
c213ca07 AA	162	* access to kfifos: *
	163	* xmitqueue, writequeue, *
	164	* immqueue, mgmtqueue */
	165	unsigned long suspend_tx; /* suspend Tx */
	166
	167	/* abort */
	168	wait_queue_head_t ehwait; /* used in eh_abort() */
	169	struct iscsi_tm tmhdr;
	170	struct timer_list tmabort_timer; /* abort timer */
	171	int tmabort_state; /* see TMABORT_INITIAL, etc.*/
	172
	173	/* negotiated params */
	174	int max_recv_dlength;
	175	int max_xmit_dlength;
	176	int hdrdgst_en;
	177	int datadgst_en;
	178
	179	/* MIB-statistics */
	180	uint64_t txdata_octets;
	181	uint64_t rxdata_octets;
	182	uint32_t scsicmd_pdus_cnt;
	183	uint32_t dataout_pdus_cnt;
	184	uint32_t scsirsp_pdus_cnt;
	185	uint32_t datain_pdus_cnt;
	186	uint32_t r2t_pdus_cnt;
	187	uint32_t tmfcmd_pdus_cnt;
	188	int32_t tmfrsp_pdus_cnt;
	189
	190	/* custom statistics */
	191	uint32_t sendpage_failures_cnt;
	192	uint32_t discontiguous_hdr_cnt;
	193	uint32_t eh_abort_cnt;
	194	};
	195
	196	struct iscsi_session {
	197	/* iSCSI session-wide sequencing */
	198	uint32_t cmdsn;
	199	uint32_t exp_cmdsn;
	200	uint32_t max_cmdsn;
	201
	202	/* configuration */
	203	int initial_r2t_en;
	204	int max_r2t;
	205	int imm_data_en;
	206	int first_burst;
	207	int max_burst;
	208	int time2wait;
	209	int time2retain;
	210	int pdu_inorder_en;
	211	int dataseq_inorder_en;
	212	int erl;
	213	int ifmarker_en;
	214	int ofmarker_en;
	215
	216	/* control data */
	217	struct Scsi_Host *host;
	218	int id;
	219	struct iscsi_conn leadconn; / leading connection */
	220	spinlock_t lock; /* protects session state, *
	221	* sequence numbers, *
	222	* session resources: *
	223	* - cmdpool, *
	224	* - mgmtpool, *
	225	* - r2tpool */
226	int state; /* session state */
227	struct list_head item;
228	void *auth_client;
229	int conn_cnt;
230	int age; /* counts session re-opens */
231
232	struct list_head connections; /* list of connections */
233	int cmds_max; /* size of cmds array */
234	struct iscsi_cmd_task *cmds; / Original Cmds arr */
235	struct iscsi_queue cmdpool; /* PDU's pool */
236	int mgmtpool_max; /* size of mgmt array */
237	struct iscsi_mgmt_task *mgmt_cmds; / Original mgmt arr */
238	struct iscsi_queue mgmtpool; /* Mgmt PDU's pool */
239	};
240
241	struct iscsi_buf {
242	struct scatterlist sg;
243	struct kvec iov;
244	unsigned int sent;
245	};
246
247	struct iscsi_data_task {
248	struct iscsi_data hdr; /* PDU */
249	char hdrext[sizeof(__u32)]; /* Header-Digest */
250	struct list_head item; /* data queue item */
251	struct iscsi_buf digestbuf; /* digest buffer */
252	uint32_t digest; /* data digest */
253	};
254	#define ISCSI_DTASK_DEFAULT_MAX ISCSI_SG_TABLESIZE * PAGE_SIZE / 512
255
256	struct iscsi_mgmt_task {
257	struct iscsi_hdr hdr; /* mgmt. PDU */
258	char hdrext[sizeof(__u32)]; /* Header-Digest */
259	char data; / mgmt payload */
260	int xmstate; /* mgmt xmit progress */
261	int data_count; /* counts data to be sent */
262	struct iscsi_buf headbuf; /* header buffer */
263	struct iscsi_buf sendbuf; /* in progress buffer */
264	int sent;
265	uint32_t itt; /* this ITT */
266	};
267
268	struct iscsi_r2t_info {
269	__be32 ttt; /* copied from R2T */
270	__be32 exp_statsn; /* copied from R2T */
271	uint32_t data_length; /* copied from R2T */
272	uint32_t data_offset; /* copied from R2T */
273	struct iscsi_buf headbuf; /* Data-Out Header Buffer */
274	struct iscsi_buf sendbuf; /* Data-Out in progress buffer*/
275	int sent; /* R2T sequence progress */
276	int data_count; /* DATA-Out payload progress */
277	struct scatterlist sg; / per-R2T SG list */
278	int solicit_datasn;
279	struct iscsi_data_task dtask; / which data task */
280	};
281
282	struct iscsi_cmd_task {
283	struct iscsi_cmd hdr; /* iSCSI PDU header */
284	char hdrext[4sizeof(__u16)+ / AHS */
285	sizeof(__u32)]; /* HeaderDigest */
286	char pad[ISCSI_PAD_LEN];
287	int itt; /* this ITT */
288	int datasn; /* DataSN */
289	struct iscsi_buf headbuf; /* header buf (xmit) */
290	struct iscsi_buf sendbuf; /* in progress buffer*/
291	int sent;
292	struct scatterlist sg; / per-cmd SG list */
293	struct scatterlist bad_sg; / assert statement */
294	int sg_count; /* SG's to process */
295	uint32_t unsol_datasn;
296	uint32_t exp_r2tsn;
297	int xmstate; /* xmit xtate machine */
298	int imm_count; /* imm-data (bytes) */
299	int unsol_count; /* unsolicited (bytes)*/
300	int r2t_data_count; /* R2T Data-Out bytes */
301	int data_count; /* remaining Data-Out */
302	int pad_count; /* padded bytes */
303	struct scsi_cmnd sc; / associated SCSI cmd*/
304	int total_length;
305	int data_offset;
306	struct iscsi_conn conn; / used connection */
307	struct iscsi_mgmt_task mtask; / tmf mtask in progr */
308
309	struct iscsi_r2t_info r2t; / in progress R2T */
310	struct iscsi_queue r2tpool;
311	struct kfifo *r2tqueue;
312	struct iscsi_r2t_info **r2ts;
313	struct list_head dataqueue; /* Data-Out dataqueue */
314	mempool_t *datapool;
315	uint32_t datadigest; /* for recover digest */
316	int digest_count;
317	uint32_t immdigest; /* for imm data */
318	struct iscsi_buf immbuf; /* for imm data digest */
319	struct iscsi_data_task dtask; / data task in progress*/
320	int digest_offset; /* for partial buff digest */
321	};
322
323	#endif /* ISCSI_H */