xref: /linux/drivers/md/dm.h (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
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_destroy(struct dm_table *t);
40 void dm_table_event_callback(struct dm_table *t,
41 			     void (*fn)(void *), void *context);
42 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
43 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
44 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q);
45 struct list_head *dm_table_get_devices(struct dm_table *t);
46 void dm_table_presuspend_targets(struct dm_table *t);
47 void dm_table_postsuspend_targets(struct dm_table *t);
48 int dm_table_resume_targets(struct dm_table *t);
49 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
50 
51 /*
52  * To check the return value from dm_table_find_target().
53  */
54 #define dm_target_is_valid(t) ((t)->table)
55 int dm_table_barrier_ok(struct dm_table *t);
56 
57 /*-----------------------------------------------------------------
58  * A registry of target types.
59  *---------------------------------------------------------------*/
60 int dm_target_init(void);
61 void dm_target_exit(void);
62 struct target_type *dm_get_target_type(const char *name);
63 void dm_put_target_type(struct target_type *t);
64 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
65 					void *param), void *param);
66 
67 int dm_split_args(int *argc, char ***argvp, char *input);
68 
69 /*
70  * The device-mapper can be driven through one of two interfaces;
71  * ioctl or filesystem, depending which patch you have applied.
72  */
73 int dm_interface_init(void);
74 void dm_interface_exit(void);
75 
76 /*
77  * sysfs interface
78  */
79 int dm_sysfs_init(struct mapped_device *md);
80 void dm_sysfs_exit(struct mapped_device *md);
81 struct kobject *dm_kobject(struct mapped_device *md);
82 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
83 
84 /*
85  * Targets for linear and striped mappings
86  */
87 int dm_linear_init(void);
88 void dm_linear_exit(void);
89 
90 int dm_stripe_init(void);
91 void dm_stripe_exit(void);
92 
93 int dm_open_count(struct mapped_device *md);
94 int dm_lock_for_deletion(struct mapped_device *md);
95 
96 void dm_kobject_uevent(struct mapped_device *md);
97 
98 int dm_kcopyd_init(void);
99 void dm_kcopyd_exit(void);
100 
101 #endif
102