1#ifndef _LINUX_LOOP_H
2#define _LINUX_LOOP_H
3
4/*
5 * include/linux/loop.h
6 *
7 * Written by Theodore Ts'o, 3/29/93.
8 *
9 * Copyright 1993 by Theodore Ts'o.  Redistribution of this file is
10 * permitted under the GNU General Public License.
11 */
12
13#define LO_NAME_SIZE	64
14#define LO_KEY_SIZE	32
15
16#ifdef __KERNEL__
17#include <linux/bio.h>
18#include <linux/blkdev.h>
19#include <linux/spinlock.h>
20#include <linux/mutex.h>
21
22/* Possible states of device */
23enum {
24	Lo_unbound,
25	Lo_bound,
26	Lo_rundown,
27};
28
29struct loop_func_table;
30
31struct loop_device {
32	int		lo_number;
33	int		lo_refcnt;
34	loff_t		lo_offset;
35	loff_t		lo_sizelimit;
36	int		lo_flags;
37	int		(*transfer)(struct loop_device *, int cmd,
38				    struct page *raw_page, unsigned raw_off,
39				    struct page *loop_page, unsigned loop_off,
40				    int size, sector_t real_block);
41	char		lo_file_name[LO_NAME_SIZE];
42	char		lo_crypt_name[LO_NAME_SIZE];
43	char		lo_encrypt_key[LO_KEY_SIZE];
44	int		lo_encrypt_key_size;
45	struct loop_func_table *lo_encryption;
46	__u32           lo_init[2];
47	uid_t		lo_key_owner;	/* Who set the key */
48	int		(*ioctl)(struct loop_device *, int cmd,
49				 unsigned long arg);
50
51	struct file *	lo_backing_file;
52	struct block_device *lo_device;
53	unsigned	lo_blocksize;
54	void		*key_data;
55
56	gfp_t		old_gfp_mask;
57
58	spinlock_t		lo_lock;
59	struct bio 		*lo_bio;
60	struct bio		*lo_biotail;
61	int			lo_state;
62	struct completion	lo_done;
63	struct completion	lo_bh_done;
64	struct mutex		lo_ctl_mutex;
65	int			lo_pending;
66
67	request_queue_t		*lo_queue;
68};
69
70#endif /* __KERNEL__ */
71
72/*
73 * Loop flags
74 */
75enum {
76	LO_FLAGS_READ_ONLY	= 1,
77	LO_FLAGS_USE_AOPS	= 2,
78};
79
80#include <asm/posix_types.h>	/* for __kernel_old_dev_t */
81#include <asm/types.h>		/* for __u64 */
82
83/* Backwards compatibility version */
84struct loop_info {
85	int		   lo_number;		/* ioctl r/o */
86	__kernel_old_dev_t lo_device; 		/* ioctl r/o */
87	unsigned long	   lo_inode; 		/* ioctl r/o */
88	__kernel_old_dev_t lo_rdevice; 		/* ioctl r/o */
89	int		   lo_offset;
90	int		   lo_encrypt_type;
91	int		   lo_encrypt_key_size; 	/* ioctl w/o */
92	int		   lo_flags;			/* ioctl r/o */
93	char		   lo_name[LO_NAME_SIZE];
94	unsigned char	   lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
95	unsigned long	   lo_init[2];
96	char		   reserved[4];
97};
98
99struct loop_info64 {
100	__u64		   lo_device;			/* ioctl r/o */
101	__u64		   lo_inode;			/* ioctl r/o */
102	__u64		   lo_rdevice;			/* ioctl r/o */
103	__u64		   lo_offset;
104	__u64		   lo_sizelimit;/* bytes, 0 == max available */
105	__u32		   lo_number;			/* ioctl r/o */
106	__u32		   lo_encrypt_type;
107	__u32		   lo_encrypt_key_size;		/* ioctl w/o */
108	__u32		   lo_flags;			/* ioctl r/o */
109	__u8		   lo_file_name[LO_NAME_SIZE];
110	__u8		   lo_crypt_name[LO_NAME_SIZE];
111	__u8		   lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
112	__u64		   lo_init[2];
113};
114
115/*
116 * Loop filter types
117 */
118
119#define LO_CRYPT_NONE		0
120#define LO_CRYPT_XOR		1
121#define LO_CRYPT_DES		2
122#define LO_CRYPT_FISH2		3    /* Twofish encryption */
123#define LO_CRYPT_BLOW		4
124#define LO_CRYPT_CAST128	5
125#define LO_CRYPT_IDEA		6
126#define LO_CRYPT_DUMMY		9
127#define LO_CRYPT_SKIPJACK	10
128#define LO_CRYPT_CRYPTOAPI	18
129#define MAX_LO_CRYPT		20
130
131#ifdef __KERNEL__
132/* Support for loadable transfer modules */
133struct loop_func_table {
134	int number;	/* filter type */
135	int (*transfer)(struct loop_device *lo, int cmd,
136			struct page *raw_page, unsigned raw_off,
137			struct page *loop_page, unsigned loop_off,
138			int size, sector_t real_block);
139	int (*init)(struct loop_device *, const struct loop_info64 *);
140	/* release is called from loop_unregister_transfer or clr_fd */
141	int (*release)(struct loop_device *);
142	int (*ioctl)(struct loop_device *, int cmd, unsigned long arg);
143	struct module *owner;
144};
145
146int loop_register_transfer(struct loop_func_table *funcs);
147int loop_unregister_transfer(int number);
148
149#endif
150/*
151 * IOCTL commands --- we will commandeer 0x4C ('L')
152 */
153
154#define LOOP_SET_FD		0x4C00
155#define LOOP_CLR_FD		0x4C01
156#define LOOP_SET_STATUS		0x4C02
157#define LOOP_GET_STATUS		0x4C03
158#define LOOP_SET_STATUS64	0x4C04
159#define LOOP_GET_STATUS64	0x4C05
160#define LOOP_CHANGE_FD		0x4C06
161
162#endif
163