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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#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>
Ingo Molnarf85221d2006-03-23 03:00:38 -080020#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021
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
Al Virob4e3ca12005-10-21 03:22:34 -040056 gfp_t old_gfp_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
58 spinlock_t lo_lock;
Akinobu Mitae6863072009-04-17 08:41:21 +020059 struct bio_list lo_bio_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 int lo_state;
Ingo Molnarf85221d2006-03-23 03:00:38 -080061 struct mutex lo_ctl_mutex;
Serge E. Hallyn6c997912006-09-29 01:59:11 -070062 struct task_struct *lo_thread;
63 wait_queue_head_t lo_event;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
Arnd Bergmann01e457c2007-07-23 18:44:00 -070065 struct request_queue *lo_queue;
Ken Chen73285082007-05-08 00:28:20 -070066 struct gendisk *lo_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067};
68
69#endif /* __KERNEL__ */
70
71/*
72 * Loop flags
73 */
74enum {
75 LO_FLAGS_READ_ONLY = 1,
76 LO_FLAGS_USE_AOPS = 2,
David Woodhouse96c58652008-02-06 01:36:27 -080077 LO_FLAGS_AUTOCLEAR = 4,
Linus Torvalds1da177e2005-04-16 15:20:36 -070078};
79
80#include <asm/posix_types.h> /* for __kernel_old_dev_t */
Jaswinder Singh Rajput00bfdda2009-01-15 13:51:26 -080081#include <linux/types.h> /* for __u64 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
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
J. R. Okajima53d66602009-03-31 15:23:43 -0700161#define LOOP_SET_CAPACITY 0x4C07
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
Kay Sievers770fe302011-07-31 22:08:04 +0200163/* /dev/loop-control interface */
164#define LOOP_CTL_ADD 0x4C80
165#define LOOP_CTL_REMOVE 0x4C81
166#define LOOP_CTL_GET_FREE 0x4C82
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167#endif