1 #ifndef _LINUX_LOOP_H
2 #define _LINUX_LOOP_H
3
4 #include <linux/kdev_t.h>
5
6 /*
7 * include/linux/loop.h
8 *
9 * Written by Theodore Ts'o, 3/29/93.
10 *
11 * Copyright 1993 by Theodore Ts'o. Redistribution of this file is
12 * permitted under the GNU Public License.
13 */
14
15 #define LO_NAME_SIZE 64
16 #define LO_KEY_SIZE 32
17
18 #ifdef __KERNEL__
19
20 struct loop_device {
21 int lo_number;
22 struct dentry *lo_dentry;
23 int lo_refcnt;
24 kdev_t lo_device;
25 int lo_offset;
26 int lo_encrypt_type;
27 int lo_encrypt_key_size;
28 int lo_flags;
29 int (*transfer)(struct loop_device *, int cmd,
30 char *raw_buf, char *loop_buf, int size,
31 int real_block);
32 char lo_name[LO_NAME_SIZE];
33 char lo_encrypt_key[LO_KEY_SIZE];
34 __u32 lo_init[2];
35 uid_t lo_key_owner; /* Who set the key */
36 int (*ioctl)(struct loop_device *, int cmd,
37 unsigned long arg);
38
39 struct file * lo_backing_file;
40 void *key_data;
41 char key_reserved[48]; /* for use by the filter modules */
42 };
43
44 typedef int (* transfer_proc_t)(struct loop_device *, int cmd,
45 char *raw_buf, char *loop_buf, int size,
46 int real_block);
47
48 #endif /* __KERNEL__ */
49
50 /*
51 * Loop flags
52 */
53 #define LO_FLAGS_DO_BMAP 0x00000001
54 #define LO_FLAGS_READ_ONLY 0x00000002
55
56 /*
57 * Note that this structure gets the wrong offsets when directly used
58 * from a glibc program, because glibc has a 32bit dev_t.
59 * Prevent people from shooting in their own foot.
60 */
61 #if __GLIBC__ >= 2 && !defined(dev_t)
62 #error "Wrong dev_t in loop.h"
63 #endif
64
65 /*
66 * This uses kdev_t because glibc currently has no appropiate
67 * conversion version for the loop ioctls.
68 * The situation is very unpleasant
69 */
70
71 struct loop_info {
72 int lo_number; /* ioctl r/o */
73 dev_t lo_device; /* ioctl r/o */
74 unsigned long lo_inode; /* ioctl r/o */
75 dev_t lo_rdevice; /* ioctl r/o */
76 int lo_offset;
77 int lo_encrypt_type;
78 int lo_encrypt_key_size; /* ioctl w/o */
79 int lo_flags; /* ioctl r/o */
80 char lo_name[LO_NAME_SIZE];
81 unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
82 unsigned long lo_init[2];
83 char reserved[4];
84 };
85
86 /*
87 * Loop filter types
88 */
89
90 #define LO_CRYPT_NONE 0
91 #define LO_CRYPT_XOR 1
92 #define LO_CRYPT_DES 2
93 #define LO_CRYPT_FISH2 3 /* Brand new Twofish encryption */
94 #define LO_CRYPT_BLOW 4
95 #define LO_CRYPT_CAST128 5
96 #define LO_CRYPT_IDEA 6
97 #define LO_CRYPT_DUMMY 9
98 #define LO_CRYPT_SKIPJACK 10
99 #define MAX_LO_CRYPT 20
100
101 #ifdef __KERNEL__
102 /* Support for loadable transfer modules */
103 struct loop_func_table {
104 int number; /* filter type */
105 int (*transfer)(struct loop_device *lo, int cmd,
106 char *raw_buf, char *loop_buf, int size,
107 int real_block);
108 int (*init)(struct loop_device *, struct loop_info *);
109 /* release is called from loop_unregister_transfer or clr_fd */
110 int (*release)(struct loop_device *);
111 int (*ioctl)(struct loop_device *, int cmd, unsigned long arg);
112 /* lock and unlock manage the module use counts */
113 void (*lock)(struct loop_device *);
114 void (*unlock)(struct loop_device *);
115 };
116
117 int loop_register_transfer(struct loop_func_table *funcs);
118 int loop_unregister_transfer(int number);
119
120 #endif
121 /*
122 * IOCTL commands --- we will commandeer 0x4C ('L')
123 */
124
125 #define LOOP_SET_FD 0x4C00
126 #define LOOP_CLR_FD 0x4C01
127 #define LOOP_SET_STATUS 0x4C02
128 #define LOOP_GET_STATUS 0x4C03
129
130 #endif
131
This page was automatically generated by the
LXR engine.
Visit the LXR main site for more
information.