xref: /linux/drivers/md/dm.h (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
1 /*
2  * Internal header file for device mapper
3  *
4  * Copyright (C) 2001, 2002 Sistina Software
5  * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
6  *
7  * This file is released under the LGPL.
8  */
9 
10 #ifndef DM_INTERNAL_H
11 #define DM_INTERNAL_H
12 
13 #include <linux/fs.h>
14 #include <linux/device-mapper.h>
15 #include <linux/list.h>
16 #include <linux/blkdev.h>
17 #include <linux/hdreg.h>
18 
19 /*
20  * Suspend feature flags
21  */
22 #define DM_SUSPEND_LOCKFS_FLAG		(1 << 0)
23 #define DM_SUSPEND_NOFLUSH_FLAG		(1 << 1)
24 
25 /*
26  * List of devices that a metadevice uses and should open/close.
27  */
28 struct dm_dev_internal {
29 	struct list_head list;
30 	atomic_t count;
31 	struct dm_dev dm_dev;
32 };
33 
34 struct dm_table;
35 
36 /*-----------------------------------------------------------------
37  * Internal table functions.
38  *---------------------------------------------------------------*/
39 void dm_table_event_callback(struct dm_table *t,
40 			     void (*fn)(void *), void *context);
41 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
42 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
43 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q);
44 struct list_head *dm_table_get_devices(struct dm_table *t);
45 void dm_table_presuspend_targets(struct dm_table *t);
46 void dm_table_postsuspend_targets(struct dm_table *t);
47 int dm_table_resume_targets(struct dm_table *t);
48 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
49 
50 /*
51  * To check the return value from dm_table_find_target().
52  */
53 #define dm_target_is_valid(t) ((t)->table)
54 
55 /*-----------------------------------------------------------------
56  * A registry of target types.
57  *---------------------------------------------------------------*/
58 int dm_target_init(void);
59 void dm_target_exit(void);
60 struct target_type *dm_get_target_type(const char *name);
61 void dm_put_target_type(struct target_type *t);
62 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
63 					void *param), void *param);
64 
65 int dm_split_args(int *argc, char ***argvp, char *input);
66 
67 /*
68  * The device-mapper can be driven through one of two interfaces;
69  * ioctl or filesystem, depending which patch you have applied.
70  */
71 int dm_interface_init(void);
72 void dm_interface_exit(void);
73 
74 /*
75  * Targets for linear and striped mappings
76  */
77 int dm_linear_init(void);
78 void dm_linear_exit(void);
79 
80 int dm_stripe_init(void);
81 void dm_stripe_exit(void);
82 
83 int dm_open_count(struct mapped_device *md);
84 int dm_lock_for_deletion(struct mapped_device *md);
85 
86 void dm_kobject_uevent(struct mapped_device *md);
87 
88 int dm_kcopyd_init(void);
89 void dm_kcopyd_exit(void);
90 
91 #endif
92