xref: /openbmc/linux/drivers/md/dm.h (revision 84764a41)
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  * Status feature flags
27  */
28 #define DM_STATUS_NOFLUSH_FLAG		(1 << 0)
29 
30 /*
31  * Type of table and mapped_device's mempool
32  */
33 #define DM_TYPE_NONE		0
34 #define DM_TYPE_BIO_BASED	1
35 #define DM_TYPE_REQUEST_BASED	2
36 
37 /*
38  * List of devices that a metadevice uses and should open/close.
39  */
40 struct dm_dev_internal {
41 	struct list_head list;
42 	atomic_t count;
43 	struct dm_dev dm_dev;
44 };
45 
46 struct dm_table;
47 struct dm_md_mempools;
48 
49 /*-----------------------------------------------------------------
50  * Internal table functions.
51  *---------------------------------------------------------------*/
52 void dm_table_destroy(struct dm_table *t);
53 void dm_table_event_callback(struct dm_table *t,
54 			     void (*fn)(void *), void *context);
55 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
56 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
57 bool dm_table_has_no_data_devices(struct dm_table *table);
58 int dm_calculate_queue_limits(struct dm_table *table,
59 			      struct queue_limits *limits);
60 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
61 			       struct queue_limits *limits);
62 struct list_head *dm_table_get_devices(struct dm_table *t);
63 void dm_table_presuspend_targets(struct dm_table *t);
64 void dm_table_postsuspend_targets(struct dm_table *t);
65 int dm_table_resume_targets(struct dm_table *t);
66 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
67 int dm_table_any_busy_target(struct dm_table *t);
68 unsigned dm_table_get_type(struct dm_table *t);
69 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
70 bool dm_table_request_based(struct dm_table *t);
71 bool dm_table_supports_discards(struct dm_table *t);
72 int dm_table_alloc_md_mempools(struct dm_table *t);
73 void dm_table_free_md_mempools(struct dm_table *t);
74 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
75 
76 int dm_queue_merge_is_compulsory(struct request_queue *q);
77 
78 void dm_lock_md_type(struct mapped_device *md);
79 void dm_unlock_md_type(struct mapped_device *md);
80 void dm_set_md_type(struct mapped_device *md, unsigned type);
81 unsigned dm_get_md_type(struct mapped_device *md);
82 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
83 
84 int dm_setup_md_queue(struct mapped_device *md);
85 
86 /*
87  * To check the return value from dm_table_find_target().
88  */
89 #define dm_target_is_valid(t) ((t)->table)
90 
91 /*
92  * To check whether the target type is request-based or not (bio-based).
93  */
94 #define dm_target_request_based(t) ((t)->type->map_rq != NULL)
95 
96 /*-----------------------------------------------------------------
97  * A registry of target types.
98  *---------------------------------------------------------------*/
99 int dm_target_init(void);
100 void dm_target_exit(void);
101 struct target_type *dm_get_target_type(const char *name);
102 void dm_put_target_type(struct target_type *tt);
103 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
104 					void *param), void *param);
105 
106 int dm_split_args(int *argc, char ***argvp, char *input);
107 
108 /*
109  * Is this mapped_device being deleted?
110  */
111 int dm_deleting_md(struct mapped_device *md);
112 
113 /*
114  * Is this mapped_device suspended?
115  */
116 int dm_suspended_md(struct mapped_device *md);
117 
118 /*
119  * The device-mapper can be driven through one of two interfaces;
120  * ioctl or filesystem, depending which patch you have applied.
121  */
122 int dm_interface_init(void);
123 void dm_interface_exit(void);
124 
125 /*
126  * sysfs interface
127  */
128 int dm_sysfs_init(struct mapped_device *md);
129 void dm_sysfs_exit(struct mapped_device *md);
130 struct kobject *dm_kobject(struct mapped_device *md);
131 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
132 
133 /*
134  * Targets for linear and striped mappings
135  */
136 int dm_linear_init(void);
137 void dm_linear_exit(void);
138 
139 int dm_stripe_init(void);
140 void dm_stripe_exit(void);
141 
142 /*
143  * mapped_device operations
144  */
145 void dm_destroy(struct mapped_device *md);
146 void dm_destroy_immediate(struct mapped_device *md);
147 int dm_open_count(struct mapped_device *md);
148 int dm_lock_for_deletion(struct mapped_device *md);
149 
150 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
151 		      unsigned cookie);
152 
153 int dm_io_init(void);
154 void dm_io_exit(void);
155 
156 int dm_kcopyd_init(void);
157 void dm_kcopyd_exit(void);
158 
159 /*
160  * Mempool operations
161  */
162 struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity);
163 void dm_free_md_mempools(struct dm_md_mempools *pools);
164 
165 #endif
166