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#ifndef _LINUX_LOOP_H
#define _LINUX_LOOP_H
#include <linux/kdev_t.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__
/* Possible states of device */
enum {
Lo_unbound,
Lo_bound,
Lo_rundown,
};
struct loop_device {
int lo_number;
int lo_refcnt;
kdev_t lo_device;
int lo_offset;
int lo_encrypt_type;
int lo_encrypt_key_size;
int lo_flags;
int (*transfer)(struct loop_device *, int cmd,
char *raw_buf, char *loop_buf, int size,
int real_block);
char lo_name[LO_NAME_SIZE];
char lo_encrypt_key[LO_KEY_SIZE];
__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;
void *key_data;
char key_reserved[48]; /* for use by the filter modules */
int old_gfp_mask;
spinlock_t lo_lock;
struct buffer_head *lo_bh;
struct buffer_head *lo_bhtail;
int lo_state;
struct semaphore lo_sem;
struct semaphore lo_ctl_mutex;
struct semaphore lo_bh_mutex;
atomic_t lo_pending;
};
typedef int (* transfer_proc_t)(struct loop_device *, int cmd,
char *raw_buf, char *loop_buf, int size,
int real_block);
static inline int lo_do_transfer(struct loop_device *lo, int cmd, char *rbuf,
char *lbuf, int size, int rblock)
{
if (!lo->transfer)
return 0;
return lo->transfer(lo, cmd, rbuf, lbuf, size, rblock);
}
#endif /* __KERNEL__ */
/*
* Loop flags
*/
#define LO_FLAGS_DO_BMAP 1
#define LO_FLAGS_READ_ONLY 2
#define LO_FLAGS_BH_REMAP 4
/*
* Note that this structure gets the wrong offsets when directly used
* from a glibc program, because glibc has a 32bit dev_t.
* Prevent people from shooting in their own foot.
*/
#if __GLIBC__ >= 2 && !defined(dev_t)
#error "Wrong dev_t in loop.h"
#endif
/*
* This uses kdev_t because glibc currently has no appropiate
* conversion version for the loop ioctls.
* The situation is very unpleasant
*/
struct loop_info {
int lo_number; /* ioctl r/o */
dev_t lo_device; /* ioctl r/o */
unsigned long lo_inode; /* ioctl r/o */
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];
};
/*
* Loop filter types
*/
#define LO_CRYPT_NONE 0
#define LO_CRYPT_XOR 1
#define LO_CRYPT_DES 2
#define LO_CRYPT_FISH2 3 /* Brand new 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 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, char *raw_buf,
char *loop_buf, int size, int real_block);
int (*init)(struct loop_device *, struct loop_info *);
/* 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);
/* lock and unlock manage the module use counts */
void (*lock)(struct loop_device *);
void (*unlock)(struct loop_device *);
};
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
#endif
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