#ifndef _LINUX_LOOP_H

#define _LINUX_LOOP_H

/*

 * include/linux/loop.h

 *

 * Written by Theodore Ts'o, 3/29/93.

 *

 * Copyright 1993 by Theodore Ts'o.  Redistribution of this file is

 * permitted under the GNU General Public License.

 */

#define LO_NAME_SIZE	64

#define LO_KEY_SIZE	32

#ifdef __KERNEL__

#include <linux/bio.h>

#include <linux/blkdev.h>

#include <linux/spinlock.h>

#include <linux/mutex.h>

/* Possible states of device */

enum {

	Lo_unbound,

	Lo_bound,

	Lo_rundown,

};

struct loop_func_table;

struct loop_device {

	int		lo_number;

	int		lo_refcnt;

	loff_t		lo_offset;

	loff_t		lo_sizelimit;

	int		lo_flags;

	int		(*transfer)(struct loop_device *, int cmd,

				    struct page *raw_page, unsigned raw_off,

				    struct page *loop_page, unsigned loop_off,

				    int size, sector_t real_block);

	char		lo_file_name[LO_NAME_SIZE];

	char		lo_crypt_name[LO_NAME_SIZE];

	char		lo_encrypt_key[LO_KEY_SIZE];

	int		lo_encrypt_key_size;

	struct loop_func_table *lo_encryption;

	__u32           lo_init[2];

	uid_t		lo_key_owner;	/* Who set the key */

	int		(*ioctl)(struct loop_device *, int cmd, 

				 unsigned long arg); 

	struct file *	lo_backing_file;

	struct block_device *lo_device;

	unsigned	lo_blocksize;

	void		*key_data; 

	gfp_t		old_gfp_mask;

	spinlock_t		lo_lock;

	struct bio 		*lo_bio;

	struct bio		*lo_biotail;

	int			lo_state;

	struct mutex		lo_ctl_mutex;

	struct task_struct	*lo_thread;

	wait_queue_head_t	lo_event;

	struct request_queue	*lo_queue;

	struct gendisk		*lo_disk;

	struct list_head	lo_list;

};

#endif /* __KERNEL__ */

/*

 * Loop flags

 */

enum {

	LO_FLAGS_READ_ONLY	= 1,

	LO_FLAGS_USE_AOPS	= 2,

	LO_FLAGS_AUTOCLEAR	= 4,

};

#include <asm/posix_types.h>	/* for __kernel_old_dev_t */

#include <asm/types.h>		/* for __u64 */

/* Backwards compatibility version */

struct loop_info {

	int		   lo_number;		/* ioctl r/o */

	__kernel_old_dev_t lo_device; 		/* ioctl r/o */

	unsigned long	   lo_inode; 		/* ioctl r/o */

	__kernel_old_dev_t lo_rdevice; 		/* ioctl r/o */

	int		   lo_offset;

	int		   lo_encrypt_type;

	int		   lo_encrypt_key_size; 	/* ioctl w/o */

	int		   lo_flags;			/* ioctl r/o */

	char		   lo_name[LO_NAME_SIZE];

	unsigned char	   lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */

	unsigned long	   lo_init[2];

	char		   reserved[4];

};

struct loop_info64 {

	__u64		   lo_device;			/* ioctl r/o */

	__u64		   lo_inode;			/* ioctl r/o */

	__u64		   lo_rdevice;			/* ioctl r/o */

	__u64		   lo_offset;

	__u64		   lo_sizelimit;/* bytes, 0 == max available */

	__u32		   lo_number;			/* ioctl r/o */

	__u32		   lo_encrypt_type;

	__u32		   lo_encrypt_key_size;		/* ioctl w/o */

	__u32		   lo_flags;			/* ioctl r/o */

	__u8		   lo_file_name[LO_NAME_SIZE];

	__u8		   lo_crypt_name[LO_NAME_SIZE];

	__u8		   lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */

	__u64		   lo_init[2];

};

/*

 * Loop filter types

 */

#define LO_CRYPT_NONE		0

#define LO_CRYPT_XOR		1

#define LO_CRYPT_DES		2

#define LO_CRYPT_FISH2		3    /* Twofish encryption */

#define LO_CRYPT_BLOW		4

#define LO_CRYPT_CAST128	5

#define LO_CRYPT_IDEA		6

#define LO_CRYPT_DUMMY		9

#define LO_CRYPT_SKIPJACK	10

#define LO_CRYPT_CRYPTOAPI	18

#define MAX_LO_CRYPT		20

#ifdef __KERNEL__

/* Support for loadable transfer modules */

struct loop_func_table {

	int number;	/* filter type */ 

	int (*transfer)(struct loop_device *lo, int cmd,

			struct page *raw_page, unsigned raw_off,

			struct page *loop_page, unsigned loop_off,

			int size, sector_t real_block);

	int (*init)(struct loop_device *, const struct loop_info64 *); 

	/* release is called from loop_unregister_transfer or clr_fd */

	int (*release)(struct loop_device *); 

	int (*ioctl)(struct loop_device *, int cmd, unsigned long arg);

	struct module *owner;

}; 

int loop_register_transfer(struct loop_func_table *funcs);

int loop_unregister_transfer(int number); 

#endif

/*

 * IOCTL commands --- we will commandeer 0x4C ('L')

 */

#define LOOP_SET_FD		0x4C00

#define LOOP_CLR_FD		0x4C01

#define LOOP_SET_STATUS		0x4C02

#define LOOP_GET_STATUS		0x4C03

#define LOOP_SET_STATUS64	0x4C04

#define LOOP_GET_STATUS64	0x4C05

#define LOOP_CHANGE_FD		0x4C06

#endif