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1/* SPDX-License-Identifier: GPL-1.0+ WITH Linux-syscall-note */
2/*
3 * Copyright 1993 by Theodore Ts'o.
4 */
5#ifndef _LINUX_LOOP_H
6#define _LINUX_LOOP_H
7
8
9#define LO_NAME_SIZE 64
10#define LO_KEY_SIZE 32
11
12
13/*
14 * Loop flags
15 */
16enum {
17 LO_FLAGS_READ_ONLY = 1,
18 LO_FLAGS_AUTOCLEAR = 4,
19 LO_FLAGS_PARTSCAN = 8,
20 LO_FLAGS_DIRECT_IO = 16,
21};
22
23/* LO_FLAGS that can be set using LOOP_SET_STATUS(64) */
24#define LOOP_SET_STATUS_SETTABLE_FLAGS (LO_FLAGS_AUTOCLEAR | LO_FLAGS_PARTSCAN)
25
26/* LO_FLAGS that can be cleared using LOOP_SET_STATUS(64) */
27#define LOOP_SET_STATUS_CLEARABLE_FLAGS (LO_FLAGS_AUTOCLEAR)
28
29/* LO_FLAGS that can be set using LOOP_CONFIGURE */
30#define LOOP_CONFIGURE_SETTABLE_FLAGS (LO_FLAGS_READ_ONLY | LO_FLAGS_AUTOCLEAR \
31 | LO_FLAGS_PARTSCAN | LO_FLAGS_DIRECT_IO)
32
33#include <asm/posix_types.h> /* for __kernel_old_dev_t */
34#include <linux/types.h> /* for __u64 */
35
36/* Backwards compatibility version */
37struct loop_info {
38 int lo_number; /* ioctl r/o */
39 __kernel_old_dev_t lo_device; /* ioctl r/o */
40 unsigned long lo_inode; /* ioctl r/o */
41 __kernel_old_dev_t lo_rdevice; /* ioctl r/o */
42 int lo_offset;
43 int lo_encrypt_type; /* obsolete, ignored */
44 int lo_encrypt_key_size; /* ioctl w/o */
45 int lo_flags;
46 char lo_name[LO_NAME_SIZE];
47 unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
48 unsigned long lo_init[2];
49 char reserved[4];
50};
51
52struct loop_info64 {
53 __u64 lo_device; /* ioctl r/o */
54 __u64 lo_inode; /* ioctl r/o */
55 __u64 lo_rdevice; /* ioctl r/o */
56 __u64 lo_offset;
57 __u64 lo_sizelimit;/* bytes, 0 == max available */
58 __u32 lo_number; /* ioctl r/o */
59 __u32 lo_encrypt_type; /* obsolete, ignored */
60 __u32 lo_encrypt_key_size; /* ioctl w/o */
61 __u32 lo_flags;
62 __u8 lo_file_name[LO_NAME_SIZE];
63 __u8 lo_crypt_name[LO_NAME_SIZE];
64 __u8 lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
65 __u64 lo_init[2];
66};
67
68/**
69 * struct loop_config - Complete configuration for a loop device.
70 * @fd: fd of the file to be used as a backing file for the loop device.
71 * @block_size: block size to use; ignored if 0.
72 * @info: struct loop_info64 to configure the loop device with.
73 *
74 * This structure is used with the LOOP_CONFIGURE ioctl, and can be used to
75 * atomically setup and configure all loop device parameters at once.
76 */
77struct loop_config {
78 __u32 fd;
79 __u32 block_size;
80 struct loop_info64 info;
81 __u64 __reserved[8];
82};
83
84/*
85 * Loop filter types
86 */
87
88#define LO_CRYPT_NONE 0
89#define LO_CRYPT_XOR 1
90#define LO_CRYPT_DES 2
91#define LO_CRYPT_FISH2 3 /* Twofish encryption */
92#define LO_CRYPT_BLOW 4
93#define LO_CRYPT_CAST128 5
94#define LO_CRYPT_IDEA 6
95#define LO_CRYPT_DUMMY 9
96#define LO_CRYPT_SKIPJACK 10
97#define LO_CRYPT_CRYPTOAPI 18
98#define MAX_LO_CRYPT 20
99
100/*
101 * IOCTL commands --- we will commandeer 0x4C ('L')
102 */
103
104#define LOOP_SET_FD 0x4C00
105#define LOOP_CLR_FD 0x4C01
106#define LOOP_SET_STATUS 0x4C02
107#define LOOP_GET_STATUS 0x4C03
108#define LOOP_SET_STATUS64 0x4C04
109#define LOOP_GET_STATUS64 0x4C05
110#define LOOP_CHANGE_FD 0x4C06
111#define LOOP_SET_CAPACITY 0x4C07
112#define LOOP_SET_DIRECT_IO 0x4C08
113#define LOOP_SET_BLOCK_SIZE 0x4C09
114#define LOOP_CONFIGURE 0x4C0A
115
116/* /dev/loop-control interface */
117#define LOOP_CTL_ADD 0x4C80
118#define LOOP_CTL_REMOVE 0x4C81
119#define LOOP_CTL_GET_FREE 0x4C82
120#endif /* _LINUX_LOOP_H */