--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/include/linux/loop.h	Sun Jan 11 20:20:11 2009 +0100
@@ -0,0 +1,164 @@
+#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