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991d9fa0 JT |
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 | ||
c4a69ecd MS |
14 | /* |
15 | * The metadata device is currently limited in size. | |
16 | * | |
17 | * We have one block of index, which can hold 255 index entries. Each | |
18 | * index entry contains allocation info about 16k metadata blocks. | |
19 | */ | |
20 | #define THIN_METADATA_MAX_SECTORS (255 * (1 << 14) * (THIN_METADATA_BLOCK_SIZE / (1 << SECTOR_SHIFT))) | |
21 | ||
22 | /* | |
23 | * A metadata device larger than 16GB triggers a warning. | |
24 | */ | |
25 | #define THIN_METADATA_MAX_SECTORS_WARNING (16 * (1024 * 1024 * 1024 >> SECTOR_SHIFT)) | |
26 | ||
991d9fa0 JT |
27 | /*----------------------------------------------------------------*/ |
28 | ||
29 | struct dm_pool_metadata; | |
30 | struct dm_thin_device; | |
31 | ||
32 | /* | |
33 | * Device identifier | |
34 | */ | |
35 | typedef uint64_t dm_thin_id; | |
36 | ||
37 | /* | |
38 | * Reopens or creates a new, empty metadata volume. | |
39 | */ | |
40 | struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, | |
41 | sector_t data_block_size); | |
42 | ||
43 | int dm_pool_metadata_close(struct dm_pool_metadata *pmd); | |
44 | ||
45 | /* | |
46 | * Compat feature flags. Any incompat flags beyond the ones | |
47 | * specified below will prevent use of the thin metadata. | |
48 | */ | |
49 | #define THIN_FEATURE_COMPAT_SUPP 0UL | |
50 | #define THIN_FEATURE_COMPAT_RO_SUPP 0UL | |
51 | #define THIN_FEATURE_INCOMPAT_SUPP 0UL | |
52 | ||
53 | /* | |
54 | * Device creation/deletion. | |
55 | */ | |
56 | int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev); | |
57 | ||
58 | /* | |
59 | * An internal snapshot. | |
60 | * | |
61 | * You can only snapshot a quiesced origin i.e. one that is either | |
62 | * suspended or not instanced at all. | |
63 | */ | |
64 | int dm_pool_create_snap(struct dm_pool_metadata *pmd, dm_thin_id dev, | |
65 | dm_thin_id origin); | |
66 | ||
67 | /* | |
68 | * Deletes a virtual device from the metadata. It _is_ safe to call this | |
69 | * when that device is open. Operations on that device will just start | |
70 | * failing. You still need to call close() on the device. | |
71 | */ | |
72 | int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd, | |
73 | dm_thin_id dev); | |
74 | ||
75 | /* | |
76 | * Commits _all_ metadata changes: device creation, deletion, mapping | |
77 | * updates. | |
78 | */ | |
79 | int dm_pool_commit_metadata(struct dm_pool_metadata *pmd); | |
80 | ||
81 | /* | |
82 | * Set/get userspace transaction id. | |
83 | */ | |
84 | int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd, | |
85 | uint64_t current_id, | |
86 | uint64_t new_id); | |
87 | ||
88 | int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd, | |
89 | uint64_t *result); | |
90 | ||
91 | /* | |
92 | * Hold/get root for userspace transaction. | |
cc8394d8 JT |
93 | * |
94 | * The metadata snapshot is a copy of the current superblock (minus the | |
95 | * space maps). Userland can access the data structures for READ | |
96 | * operations only. A small performance hit is incurred by providing this | |
97 | * copy of the metadata to userland due to extra copy-on-write operations | |
98 | * on the metadata nodes. Release this as soon as you finish with it. | |
991d9fa0 | 99 | */ |
cc8394d8 JT |
100 | int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd); |
101 | int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd); | |
991d9fa0 | 102 | |
cc8394d8 JT |
103 | int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd, |
104 | dm_block_t *result); | |
991d9fa0 JT |
105 | |
106 | /* | |
107 | * Actions on a single virtual device. | |
108 | */ | |
109 | ||
110 | /* | |
111 | * Opening the same device more than once will fail with -EBUSY. | |
112 | */ | |
113 | int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev, | |
114 | struct dm_thin_device **td); | |
115 | ||
116 | int dm_pool_close_thin_device(struct dm_thin_device *td); | |
117 | ||
118 | dm_thin_id dm_thin_dev_id(struct dm_thin_device *td); | |
119 | ||
120 | struct dm_thin_lookup_result { | |
121 | dm_block_t block; | |
17b7d63f | 122 | unsigned shared:1; |
991d9fa0 JT |
123 | }; |
124 | ||
125 | /* | |
126 | * Returns: | |
127 | * -EWOULDBLOCK iff @can_block is set and would block. | |
128 | * -ENODATA iff that mapping is not present. | |
129 | * 0 success | |
130 | */ | |
131 | int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, | |
132 | int can_block, struct dm_thin_lookup_result *result); | |
133 | ||
134 | /* | |
135 | * Obtain an unused block. | |
136 | */ | |
137 | int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result); | |
138 | ||
139 | /* | |
140 | * Insert or remove block. | |
141 | */ | |
142 | int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block, | |
143 | dm_block_t data_block); | |
144 | ||
145 | int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block); | |
146 | ||
147 | /* | |
148 | * Queries. | |
149 | */ | |
150 | int dm_thin_get_highest_mapped_block(struct dm_thin_device *td, | |
151 | dm_block_t *highest_mapped); | |
152 | ||
153 | int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result); | |
154 | ||
155 | int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, | |
156 | dm_block_t *result); | |
157 | ||
158 | int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd, | |
159 | dm_block_t *result); | |
160 | ||
161 | int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd, | |
162 | dm_block_t *result); | |
163 | ||
164 | int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result); | |
165 | ||
166 | int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result); | |
167 | ||
168 | /* | |
169 | * Returns -ENOSPC if the new size is too small and already allocated | |
170 | * blocks would be lost. | |
171 | */ | |
172 | int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size); | |
173 | ||
174 | /*----------------------------------------------------------------*/ | |
175 | ||
176 | #endif |