xref: /linux/drivers/md/dm.h (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
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  * Type of table and mapped_device's mempool
27  */
28 #define DM_TYPE_NONE		0
29 #define DM_TYPE_BIO_BASED	1
30 #define DM_TYPE_REQUEST_BASED	2
31 
32 /*
33  * List of devices that a metadevice uses and should open/close.
34  */
35 struct dm_dev_internal {
36 	struct list_head list;
37 	atomic_t count;
38 	struct dm_dev dm_dev;
39 };
40 
41 struct dm_table;
42 struct dm_md_mempools;
43 
44 /*-----------------------------------------------------------------
45  * Internal table functions.
46  *---------------------------------------------------------------*/
47 void dm_table_destroy(struct dm_table *t);
48 void dm_table_event_callback(struct dm_table *t,
49 			     void (*fn)(void *), void *context);
50 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
51 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
52 int dm_calculate_queue_limits(struct dm_table *table,
53 			      struct queue_limits *limits);
54 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
55 			       struct queue_limits *limits);
56 struct list_head *dm_table_get_devices(struct dm_table *t);
57 void dm_table_presuspend_targets(struct dm_table *t);
58 void dm_table_postsuspend_targets(struct dm_table *t);
59 int dm_table_resume_targets(struct dm_table *t);
60 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
61 int dm_table_any_busy_target(struct dm_table *t);
62 unsigned dm_table_get_type(struct dm_table *t);
63 bool dm_table_request_based(struct dm_table *t);
64 bool dm_table_supports_discards(struct dm_table *t);
65 int dm_table_alloc_md_mempools(struct dm_table *t);
66 void dm_table_free_md_mempools(struct dm_table *t);
67 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
68 
69 int dm_queue_merge_is_compulsory(struct request_queue *q);
70 
71 void dm_lock_md_type(struct mapped_device *md);
72 void dm_unlock_md_type(struct mapped_device *md);
73 void dm_set_md_type(struct mapped_device *md, unsigned type);
74 unsigned dm_get_md_type(struct mapped_device *md);
75 
76 int dm_setup_md_queue(struct mapped_device *md);
77 
78 /*
79  * To check the return value from dm_table_find_target().
80  */
81 #define dm_target_is_valid(t) ((t)->table)
82 
83 /*
84  * To check whether the target type is request-based or not (bio-based).
85  */
86 #define dm_target_request_based(t) ((t)->type->map_rq != NULL)
87 
88 /*-----------------------------------------------------------------
89  * A registry of target types.
90  *---------------------------------------------------------------*/
91 int dm_target_init(void);
92 void dm_target_exit(void);
93 struct target_type *dm_get_target_type(const char *name);
94 void dm_put_target_type(struct target_type *tt);
95 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
96 					void *param), void *param);
97 
98 int dm_split_args(int *argc, char ***argvp, char *input);
99 
100 /*
101  * Is this mapped_device being deleted?
102  */
103 int dm_deleting_md(struct mapped_device *md);
104 
105 /*
106  * Is this mapped_device suspended?
107  */
108 int dm_suspended_md(struct mapped_device *md);
109 
110 /*
111  * The device-mapper can be driven through one of two interfaces;
112  * ioctl or filesystem, depending which patch you have applied.
113  */
114 int dm_interface_init(void);
115 void dm_interface_exit(void);
116 
117 /*
118  * sysfs interface
119  */
120 int dm_sysfs_init(struct mapped_device *md);
121 void dm_sysfs_exit(struct mapped_device *md);
122 struct kobject *dm_kobject(struct mapped_device *md);
123 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
124 
125 /*
126  * Targets for linear and striped mappings
127  */
128 int dm_linear_init(void);
129 void dm_linear_exit(void);
130 
131 int dm_stripe_init(void);
132 void dm_stripe_exit(void);
133 
134 /*
135  * mapped_device operations
136  */
137 void dm_destroy(struct mapped_device *md);
138 void dm_destroy_immediate(struct mapped_device *md);
139 int dm_open_count(struct mapped_device *md);
140 int dm_lock_for_deletion(struct mapped_device *md);
141 
142 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
143 		      unsigned cookie);
144 
145 int dm_io_init(void);
146 void dm_io_exit(void);
147 
148 int dm_kcopyd_init(void);
149 void dm_kcopyd_exit(void);
150 
151 /*
152  * Mempool operations
153  */
154 struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity);
155 void dm_free_md_mempools(struct dm_md_mempools *pools);
156 
157 #endif
158