Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * include/linux/loop.h
3 *
4 * Written by Theodore Ts'o, 3/29/93.
5 *
6 * Copyright 1993 by Theodore Ts'o. Redistribution of this file is
7 * permitted under the GNU General Public License.
8 */
9#ifndef _LINUX_LOOP_H
10#define _LINUX_LOOP_H
11
12#include <linux/bio.h>
13#include <linux/blkdev.h>
14#include <linux/spinlock.h>
15#include <linux/mutex.h>
16#include <uapi/linux/loop.h>
17
18/* Possible states of device */
19enum {
20 Lo_unbound,
21 Lo_bound,
22 Lo_rundown,
23};
24
25struct loop_func_table;
26
27struct loop_device {
28 int lo_number;
29 int lo_refcnt;
30 loff_t lo_offset;
31 loff_t lo_sizelimit;
32 int lo_flags;
33 int (*transfer)(struct loop_device *, int cmd,
34 struct page *raw_page, unsigned raw_off,
35 struct page *loop_page, unsigned loop_off,
36 int size, sector_t real_block);
37 char lo_file_name[LO_NAME_SIZE];
38 char lo_crypt_name[LO_NAME_SIZE];
39 char lo_encrypt_key[LO_KEY_SIZE];
40 int lo_encrypt_key_size;
41 struct loop_func_table *lo_encryption;
42 __u32 lo_init[2];
43 kuid_t lo_key_owner; /* Who set the key */
44 int (*ioctl)(struct loop_device *, int cmd,
45 unsigned long arg);
46
47 struct file * lo_backing_file;
48 struct block_device *lo_device;
49 unsigned lo_blocksize;
50 void *key_data;
51
52 gfp_t old_gfp_mask;
53
54 spinlock_t lo_lock;
55 struct bio_list lo_bio_list;
56 int lo_state;
57 struct mutex lo_ctl_mutex;
58 struct task_struct *lo_thread;
59 wait_queue_head_t lo_event;
60
61 struct request_queue *lo_queue;
62 struct gendisk *lo_disk;
63};
64
65/* Support for loadable transfer modules */
66struct loop_func_table {
67 int number; /* filter type */
68 int (*transfer)(struct loop_device *lo, int cmd,
69 struct page *raw_page, unsigned raw_off,
70 struct page *loop_page, unsigned loop_off,
71 int size, sector_t real_block);
72 int (*init)(struct loop_device *, const struct loop_info64 *);
73 /* release is called from loop_unregister_transfer or clr_fd */
74 int (*release)(struct loop_device *);
75 int (*ioctl)(struct loop_device *, int cmd, unsigned long arg);
76 struct module *owner;
77};
78
79int loop_register_transfer(struct loop_func_table *funcs);
80int loop_unregister_transfer(int number);
81
82#endif