Root/drivers/md/dm.h

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 */
40struct dm_dev_internal {
41    struct list_head list;
42    atomic_t count;
43    struct dm_dev dm_dev;
44};
45
46struct dm_table;
47struct dm_md_mempools;
48
49/*-----------------------------------------------------------------
50 * Internal table functions.
51 *---------------------------------------------------------------*/
52void dm_table_destroy(struct dm_table *t);
53void dm_table_event_callback(struct dm_table *t,
54                 void (*fn)(void *), void *context);
55struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
56struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
57bool dm_table_has_no_data_devices(struct dm_table *table);
58int dm_calculate_queue_limits(struct dm_table *table,
59                  struct queue_limits *limits);
60void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
61                   struct queue_limits *limits);
62struct list_head *dm_table_get_devices(struct dm_table *t);
63void dm_table_presuspend_targets(struct dm_table *t);
64void dm_table_postsuspend_targets(struct dm_table *t);
65int dm_table_resume_targets(struct dm_table *t);
66int dm_table_any_congested(struct dm_table *t, int bdi_bits);
67int dm_table_any_busy_target(struct dm_table *t);
68unsigned dm_table_get_type(struct dm_table *t);
69struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
70bool dm_table_request_based(struct dm_table *t);
71bool dm_table_supports_discards(struct dm_table *t);
72int dm_table_alloc_md_mempools(struct dm_table *t);
73void dm_table_free_md_mempools(struct dm_table *t);
74struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
75
76int dm_queue_merge_is_compulsory(struct request_queue *q);
77
78void dm_lock_md_type(struct mapped_device *md);
79void dm_unlock_md_type(struct mapped_device *md);
80void dm_set_md_type(struct mapped_device *md, unsigned type);
81unsigned dm_get_md_type(struct mapped_device *md);
82struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
83
84int 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 *---------------------------------------------------------------*/
99int dm_target_init(void);
100void dm_target_exit(void);
101struct target_type *dm_get_target_type(const char *name);
102void dm_put_target_type(struct target_type *tt);
103int dm_target_iterate(void (*iter_func)(struct target_type *tt,
104                    void *param), void *param);
105
106int dm_split_args(int *argc, char ***argvp, char *input);
107
108/*
109 * Is this mapped_device being deleted?
110 */
111int dm_deleting_md(struct mapped_device *md);
112
113/*
114 * Is this mapped_device suspended?
115 */
116int 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 */
122int dm_interface_init(void);
123void dm_interface_exit(void);
124
125/*
126 * sysfs interface
127 */
128int dm_sysfs_init(struct mapped_device *md);
129void dm_sysfs_exit(struct mapped_device *md);
130struct kobject *dm_kobject(struct mapped_device *md);
131struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
132
133/*
134 * Targets for linear and striped mappings
135 */
136int dm_linear_init(void);
137void dm_linear_exit(void);
138
139int dm_stripe_init(void);
140void dm_stripe_exit(void);
141
142/*
143 * mapped_device operations
144 */
145void dm_destroy(struct mapped_device *md);
146void dm_destroy_immediate(struct mapped_device *md);
147int dm_open_count(struct mapped_device *md);
148int dm_lock_for_deletion(struct mapped_device *md);
149
150int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
151              unsigned cookie);
152
153int dm_io_init(void);
154void dm_io_exit(void);
155
156int dm_kcopyd_init(void);
157void dm_kcopyd_exit(void);
158
159/*
160 * Mempool operations
161 */
162struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity, unsigned per_bio_data_size);
163void dm_free_md_mempools(struct dm_md_mempools *pools);
164
165#endif
166

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