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-rw-r--r--drivers/md/dm-thin-metadata.h156
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diff --git a/drivers/md/dm-thin-metadata.h b/drivers/md/dm-thin-metadata.h
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1/*
2 * Copyright (C) 2010-2011 Red Hat, Inc.
3 *
4 * This file is released under the GPL.
5 */
6
7#ifndef DM_THIN_METADATA_H
8#define DM_THIN_METADATA_H
9
10#include "persistent-data/dm-block-manager.h"
11
12#define THIN_METADATA_BLOCK_SIZE 4096
13
14/*----------------------------------------------------------------*/
15
16struct dm_pool_metadata;
17struct dm_thin_device;
18
19/*
20 * Device identifier
21 */
22typedef uint64_t dm_thin_id;
23
24/*
25 * Reopens or creates a new, empty metadata volume.
26 */
27struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
28 sector_t data_block_size);
29
30int dm_pool_metadata_close(struct dm_pool_metadata *pmd);
31
32/*
33 * Compat feature flags. Any incompat flags beyond the ones
34 * specified below will prevent use of the thin metadata.
35 */
36#define THIN_FEATURE_COMPAT_SUPP 0UL
37#define THIN_FEATURE_COMPAT_RO_SUPP 0UL
38#define THIN_FEATURE_INCOMPAT_SUPP 0UL
39
40/*
41 * Device creation/deletion.
42 */
43int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev);
44
45/*
46 * An internal snapshot.
47 *
48 * You can only snapshot a quiesced origin i.e. one that is either
49 * suspended or not instanced at all.
50 */
51int dm_pool_create_snap(struct dm_pool_metadata *pmd, dm_thin_id dev,
52 dm_thin_id origin);
53
54/*
55 * Deletes a virtual device from the metadata. It _is_ safe to call this
56 * when that device is open. Operations on that device will just start
57 * failing. You still need to call close() on the device.
58 */
59int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
60 dm_thin_id dev);
61
62/*
63 * Commits _all_ metadata changes: device creation, deletion, mapping
64 * updates.
65 */
66int dm_pool_commit_metadata(struct dm_pool_metadata *pmd);
67
68/*
69 * Set/get userspace transaction id.
70 */
71int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
72 uint64_t current_id,
73 uint64_t new_id);
74
75int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
76 uint64_t *result);
77
78/*
79 * Hold/get root for userspace transaction.
80 */
81int dm_pool_hold_metadata_root(struct dm_pool_metadata *pmd);
82
83int dm_pool_get_held_metadata_root(struct dm_pool_metadata *pmd,
84 dm_block_t *result);
85
86/*
87 * Actions on a single virtual device.
88 */
89
90/*
91 * Opening the same device more than once will fail with -EBUSY.
92 */
93int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
94 struct dm_thin_device **td);
95
96int dm_pool_close_thin_device(struct dm_thin_device *td);
97
98dm_thin_id dm_thin_dev_id(struct dm_thin_device *td);
99
100struct dm_thin_lookup_result {
101 dm_block_t block;
102 int shared;
103};
104
105/*
106 * Returns:
107 * -EWOULDBLOCK iff @can_block is set and would block.
108 * -ENODATA iff that mapping is not present.
109 * 0 success
110 */
111int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
112 int can_block, struct dm_thin_lookup_result *result);
113
114/*
115 * Obtain an unused block.
116 */
117int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result);
118
119/*
120 * Insert or remove block.
121 */
122int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
123 dm_block_t data_block);
124
125int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block);
126
127/*
128 * Queries.
129 */
130int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
131 dm_block_t *highest_mapped);
132
133int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result);
134
135int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd,
136 dm_block_t *result);
137
138int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
139 dm_block_t *result);
140
141int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
142 dm_block_t *result);
143
144int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result);
145
146int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result);
147
148/*
149 * Returns -ENOSPC if the new size is too small and already allocated
150 * blocks would be lost.
151 */
152int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size);
153
154/*----------------------------------------------------------------*/
155
156#endif