mm, PM/Freezer: Disable OOM killer when tasks are frozen
[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_list         lo_bio_list;
60         int                     lo_state;
61         struct mutex            lo_ctl_mutex;
62         struct task_struct      *lo_thread;
63         wait_queue_head_t       lo_event;
64
65         struct request_queue    *lo_queue;
66         struct gendisk          *lo_disk;
67         struct list_head        lo_list;
68 };
69
70 #endif /* __KERNEL__ */
71
72 /*
73  * Loop flags
74  */
75 enum {
76         LO_FLAGS_READ_ONLY      = 1,
77         LO_FLAGS_USE_AOPS       = 2,
78         LO_FLAGS_AUTOCLEAR      = 4,
79 };
80
81 #include <asm/posix_types.h>    /* for __kernel_old_dev_t */
82 #include <linux/types.h>        /* for __u64 */
83
84 /* Backwards compatibility version */
85 struct loop_info {
86         int                lo_number;           /* ioctl r/o */
87         __kernel_old_dev_t lo_device;           /* ioctl r/o */
88         unsigned long      lo_inode;            /* ioctl r/o */
89         __kernel_old_dev_t lo_rdevice;          /* ioctl r/o */
90         int                lo_offset;
91         int                lo_encrypt_type;
92         int                lo_encrypt_key_size;         /* ioctl w/o */
93         int                lo_flags;                    /* ioctl r/o */
94         char               lo_name[LO_NAME_SIZE];
95         unsigned char      lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
96         unsigned long      lo_init[2];
97         char               reserved[4];
98 };
99
100 struct loop_info64 {
101         __u64              lo_device;                   /* ioctl r/o */
102         __u64              lo_inode;                    /* ioctl r/o */
103         __u64              lo_rdevice;                  /* ioctl r/o */
104         __u64              lo_offset;
105         __u64              lo_sizelimit;/* bytes, 0 == max available */
106         __u32              lo_number;                   /* ioctl r/o */
107         __u32              lo_encrypt_type;
108         __u32              lo_encrypt_key_size;         /* ioctl w/o */
109         __u32              lo_flags;                    /* ioctl r/o */
110         __u8               lo_file_name[LO_NAME_SIZE];
111         __u8               lo_crypt_name[LO_NAME_SIZE];
112         __u8               lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
113         __u64              lo_init[2];
114 };
115
116 /*
117  * Loop filter types
118  */
119
120 #define LO_CRYPT_NONE           0
121 #define LO_CRYPT_XOR            1
122 #define LO_CRYPT_DES            2
123 #define LO_CRYPT_FISH2          3    /* Twofish encryption */
124 #define LO_CRYPT_BLOW           4
125 #define LO_CRYPT_CAST128        5
126 #define LO_CRYPT_IDEA           6
127 #define LO_CRYPT_DUMMY          9
128 #define LO_CRYPT_SKIPJACK       10
129 #define LO_CRYPT_CRYPTOAPI      18
130 #define MAX_LO_CRYPT            20
131
132 #ifdef __KERNEL__
133 /* Support for loadable transfer modules */
134 struct loop_func_table {
135         int number;     /* filter type */ 
136         int (*transfer)(struct loop_device *lo, int cmd,
137                         struct page *raw_page, unsigned raw_off,
138                         struct page *loop_page, unsigned loop_off,
139                         int size, sector_t real_block);
140         int (*init)(struct loop_device *, const struct loop_info64 *); 
141         /* release is called from loop_unregister_transfer or clr_fd */
142         int (*release)(struct loop_device *); 
143         int (*ioctl)(struct loop_device *, int cmd, unsigned long arg);
144         struct module *owner;
145 }; 
146
147 int loop_register_transfer(struct loop_func_table *funcs);
148 int loop_unregister_transfer(int number); 
149
150 #endif
151 /*
152  * IOCTL commands --- we will commandeer 0x4C ('L')
153  */
154
155 #define LOOP_SET_FD             0x4C00
156 #define LOOP_CLR_FD             0x4C01
157 #define LOOP_SET_STATUS         0x4C02
158 #define LOOP_GET_STATUS         0x4C03
159 #define LOOP_SET_STATUS64       0x4C04
160 #define LOOP_GET_STATUS64       0x4C05
161 #define LOOP_CHANGE_FD          0x4C06
162 #define LOOP_SET_CAPACITY       0x4C07
163
164 #endif