include of <linux/types.h> is preferred over <asm/types.h>
[linux-2.6.git] / include / linux / loop.h
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 */
23 enum {
24         Lo_unbound,
25         Lo_bound,
26         Lo_rundown,
27 };
28
29 struct loop_func_table;
30
31 struct 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  */
76 enum {
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 <linux/types.h>        /* for __u64 */
84
85 /* Backwards compatibility version */
86 struct 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
101 struct 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 */
135 struct 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
148 int loop_register_transfer(struct loop_func_table *funcs);
149 int 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