projects/linux·blob v2.6.26-rc6 · refs

164 lines · 4.0 KiB

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 mutex lo_ctl_mutex;
63 struct task_struct *lo_thread;
64 wait_queue_head_t lo_event;
65
66 struct request_queue *lo_queue;
67 struct gendisk *lo_disk;
68 struct list_head lo_list;
69};
70
71#endif /* __KERNEL__ */
72
73/*
74 * Loop flags
75 */
76enum {
77 LO_FLAGS_READ_ONLY = 1,
78 LO_FLAGS_USE_AOPS = 2,
79 LO_FLAGS_AUTOCLEAR = 4,
80};
81
82#include <asm/posix_types.h> /* for __kernel_old_dev_t */
83#include <asm/types.h> /* for __u64 */
84
85/* Backwards compatibility version */
86struct loop_info {
87 int lo_number; /* ioctl r/o */
88 __kernel_old_dev_t lo_device; /* ioctl r/o */
89 unsigned long lo_inode; /* ioctl r/o */
90 __kernel_old_dev_t lo_rdevice; /* ioctl r/o */
91 int lo_offset;
92 int lo_encrypt_type;
93 int lo_encrypt_key_size; /* ioctl w/o */
94 int lo_flags; /* ioctl r/o */
95 char lo_name[LO_NAME_SIZE];
96 unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
97 unsigned long lo_init[2];
98 char reserved[4];
99};
100
101struct loop_info64 {
102 __u64 lo_device; /* ioctl r/o */
103 __u64 lo_inode; /* ioctl r/o */
104 __u64 lo_rdevice; /* ioctl r/o */
105 __u64 lo_offset;
106 __u64 lo_sizelimit;/* bytes, 0 == max available */
107 __u32 lo_number; /* ioctl r/o */
108 __u32 lo_encrypt_type;
109 __u32 lo_encrypt_key_size; /* ioctl w/o */
110 __u32 lo_flags; /* ioctl r/o */
111 __u8 lo_file_name[LO_NAME_SIZE];
112 __u8 lo_crypt_name[LO_NAME_SIZE];
113 __u8 lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
114 __u64 lo_init[2];
115};
116
117/*
118 * Loop filter types
119 */
120
121#define LO_CRYPT_NONE 0
122#define LO_CRYPT_XOR 1
123#define LO_CRYPT_DES 2
124#define LO_CRYPT_FISH2 3 /* Twofish encryption */
125#define LO_CRYPT_BLOW 4
126#define LO_CRYPT_CAST128 5
127#define LO_CRYPT_IDEA 6
128#define LO_CRYPT_DUMMY 9
129#define LO_CRYPT_SKIPJACK 10
130#define LO_CRYPT_CRYPTOAPI 18
131#define MAX_LO_CRYPT 20
132
133#ifdef __KERNEL__
134/* Support for loadable transfer modules */
135struct loop_func_table {
136 int number; /* filter type */
137 int (*transfer)(struct loop_device *lo, int cmd,
138 struct page *raw_page, unsigned raw_off,
139 struct page *loop_page, unsigned loop_off,
140 int size, sector_t real_block);
141 int (*init)(struct loop_device *, const struct loop_info64 *);
142 /* release is called from loop_unregister_transfer or clr_fd */
143 int (*release)(struct loop_device *);
144 int (*ioctl)(struct loop_device *, int cmd, unsigned long arg);
145 struct module *owner;
146};
147
148int loop_register_transfer(struct loop_func_table *funcs);
149int loop_unregister_transfer(int number);
150
151#endif
152/*
153 * IOCTL commands --- we will commandeer 0x4C ('L')
154 */
155
156#define LOOP_SET_FD 0x4C00
157#define LOOP_CLR_FD 0x4C01
158#define LOOP_SET_STATUS 0x4C02
159#define LOOP_GET_STATUS 0x4C03
160#define LOOP_SET_STATUS64 0x4C04
161#define LOOP_GET_STATUS64 0x4C05
162#define LOOP_CHANGE_FD 0x4C06
163
164#endif