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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Al Viro83a87612013-05-12 10:14:07 -04002 * loop.h
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
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 */
David Howells607ca462012-10-13 10:46:48 +01009#ifndef _LINUX_LOOP_H
10#define _LINUX_LOOP_H
Linus Torvalds1da177e2005-04-16 15:20:36 -070011
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/bio.h>
13#include <linux/blkdev.h>
14#include <linux/spinlock.h>
Ingo Molnarf85221d2006-03-23 03:00:38 -080015#include <linux/mutex.h>
David Howells607ca462012-10-13 10:46:48 +010016#include <uapi/linux/loop.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017
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];
Eric W. Biedermane4849732012-02-11 11:23:51 -080043 kuid_t lo_key_owner; /* Who set the key */
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 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
Al Virob4e3ca12005-10-21 03:22:34 -040052 gfp_t old_gfp_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54 spinlock_t lo_lock;
Akinobu Mitae6863072009-04-17 08:41:21 +020055 struct bio_list lo_bio_list;
Lukas Czerner7b5a3522012-11-30 11:42:41 +010056 unsigned int lo_bio_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 int lo_state;
Ingo Molnarf85221d2006-03-23 03:00:38 -080058 struct mutex lo_ctl_mutex;
Serge E. Hallyn6c997912006-09-29 01:59:11 -070059 struct task_struct *lo_thread;
60 wait_queue_head_t lo_event;
Lukas Czerner7b5a3522012-11-30 11:42:41 +010061 /* wait queue for incoming requests */
62 wait_queue_head_t lo_req_wait;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Arnd Bergmann01e457c2007-07-23 18:44:00 -070064 struct request_queue *lo_queue;
Ken Chen73285082007-05-08 00:28:20 -070065 struct gendisk *lo_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066};
67
Linus Torvalds1da177e2005-04-16 15:20:36 -070068/* Support for loadable transfer modules */
69struct loop_func_table {
70 int number; /* filter type */
71 int (*transfer)(struct loop_device *lo, int cmd,
72 struct page *raw_page, unsigned raw_off,
73 struct page *loop_page, unsigned loop_off,
74 int size, sector_t real_block);
75 int (*init)(struct loop_device *, const struct loop_info64 *);
76 /* release is called from loop_unregister_transfer or clr_fd */
77 int (*release)(struct loop_device *);
78 int (*ioctl)(struct loop_device *, int cmd, unsigned long arg);
79 struct module *owner;
80};
81
82int loop_register_transfer(struct loop_func_table *funcs);
83int loop_unregister_transfer(int number);
84
85#endif