xref: /openbmc/linux/drivers/md/dm.h (revision 615c36f5)
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 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
64 bool dm_table_request_based(struct dm_table *t);
65 bool dm_table_supports_discards(struct dm_table *t);
66 int dm_table_alloc_md_mempools(struct dm_table *t);
67 void dm_table_free_md_mempools(struct dm_table *t);
68 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
69 
70 int dm_queue_merge_is_compulsory(struct request_queue *q);
71 
72 void dm_lock_md_type(struct mapped_device *md);
73 void dm_unlock_md_type(struct mapped_device *md);
74 void dm_set_md_type(struct mapped_device *md, unsigned type);
75 unsigned dm_get_md_type(struct mapped_device *md);
76 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
77 
78 int dm_setup_md_queue(struct mapped_device *md);
79 
80 /*
81  * To check the return value from dm_table_find_target().
82  */
83 #define dm_target_is_valid(t) ((t)->table)
84 
85 /*
86  * To check whether the target type is request-based or not (bio-based).
87  */
88 #define dm_target_request_based(t) ((t)->type->map_rq != NULL)
89 
90 /*-----------------------------------------------------------------
91  * A registry of target types.
92  *---------------------------------------------------------------*/
93 int dm_target_init(void);
94 void dm_target_exit(void);
95 struct target_type *dm_get_target_type(const char *name);
96 void dm_put_target_type(struct target_type *tt);
97 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
98 					void *param), void *param);
99 
100 int dm_split_args(int *argc, char ***argvp, char *input);
101 
102 /*
103  * Is this mapped_device being deleted?
104  */
105 int dm_deleting_md(struct mapped_device *md);
106 
107 /*
108  * Is this mapped_device suspended?
109  */
110 int dm_suspended_md(struct mapped_device *md);
111 
112 /*
113  * The device-mapper can be driven through one of two interfaces;
114  * ioctl or filesystem, depending which patch you have applied.
115  */
116 int dm_interface_init(void);
117 void dm_interface_exit(void);
118 
119 /*
120  * sysfs interface
121  */
122 int dm_sysfs_init(struct mapped_device *md);
123 void dm_sysfs_exit(struct mapped_device *md);
124 struct kobject *dm_kobject(struct mapped_device *md);
125 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
126 
127 /*
128  * Targets for linear and striped mappings
129  */
130 int dm_linear_init(void);
131 void dm_linear_exit(void);
132 
133 int dm_stripe_init(void);
134 void dm_stripe_exit(void);
135 
136 /*
137  * mapped_device operations
138  */
139 void dm_destroy(struct mapped_device *md);
140 void dm_destroy_immediate(struct mapped_device *md);
141 int dm_open_count(struct mapped_device *md);
142 int dm_lock_for_deletion(struct mapped_device *md);
143 
144 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
145 		      unsigned cookie);
146 
147 int dm_io_init(void);
148 void dm_io_exit(void);
149 
150 int dm_kcopyd_init(void);
151 void dm_kcopyd_exit(void);
152 
153 /*
154  * Mempool operations
155  */
156 struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity);
157 void dm_free_md_mempools(struct dm_md_mempools *pools);
158 
159 #endif
160