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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, | |
66b1edc0 JT |
41 | sector_t data_block_size, |
42 | bool format_device); | |
991d9fa0 JT |
43 | |
44 | int dm_pool_metadata_close(struct dm_pool_metadata *pmd); | |
45 | ||
46 | /* | |
47 | * Compat feature flags. Any incompat flags beyond the ones | |
48 | * specified below will prevent use of the thin metadata. | |
49 | */ | |
50 | #define THIN_FEATURE_COMPAT_SUPP 0UL | |
51 | #define THIN_FEATURE_COMPAT_RO_SUPP 0UL | |
52 | #define THIN_FEATURE_INCOMPAT_SUPP 0UL | |
53 | ||
54 | /* | |
55 | * Device creation/deletion. | |
56 | */ | |
57 | int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev); | |
58 | ||
59 | /* | |
60 | * An internal snapshot. | |
61 | * | |
62 | * You can only snapshot a quiesced origin i.e. one that is either | |
63 | * suspended or not instanced at all. | |
64 | */ | |
65 | int dm_pool_create_snap(struct dm_pool_metadata *pmd, dm_thin_id dev, | |
66 | dm_thin_id origin); | |
67 | ||
68 | /* | |
69 | * Deletes a virtual device from the metadata. It _is_ safe to call this | |
70 | * when that device is open. Operations on that device will just start | |
71 | * failing. You still need to call close() on the device. | |
72 | */ | |
73 | int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd, | |
74 | dm_thin_id dev); | |
75 | ||
76 | /* | |
77 | * Commits _all_ metadata changes: device creation, deletion, mapping | |
78 | * updates. | |
79 | */ | |
80 | int dm_pool_commit_metadata(struct dm_pool_metadata *pmd); | |
81 | ||
82 | /* | |
83 | * Set/get userspace transaction id. | |
84 | */ | |
85 | int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd, | |
86 | uint64_t current_id, | |
87 | uint64_t new_id); | |
88 | ||
89 | int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd, | |
90 | uint64_t *result); | |
91 | ||
92 | /* | |
93 | * Hold/get root for userspace transaction. | |
cc8394d8 JT |
94 | * |
95 | * The metadata snapshot is a copy of the current superblock (minus the | |
96 | * space maps). Userland can access the data structures for READ | |
97 | * operations only. A small performance hit is incurred by providing this | |
98 | * copy of the metadata to userland due to extra copy-on-write operations | |
99 | * on the metadata nodes. Release this as soon as you finish with it. | |
991d9fa0 | 100 | */ |
cc8394d8 JT |
101 | int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd); |
102 | int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd); | |
991d9fa0 | 103 | |
cc8394d8 JT |
104 | int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd, |
105 | dm_block_t *result); | |
991d9fa0 JT |
106 | |
107 | /* | |
108 | * Actions on a single virtual device. | |
109 | */ | |
110 | ||
111 | /* | |
112 | * Opening the same device more than once will fail with -EBUSY. | |
113 | */ | |
114 | int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev, | |
115 | struct dm_thin_device **td); | |
116 | ||
117 | int dm_pool_close_thin_device(struct dm_thin_device *td); | |
118 | ||
119 | dm_thin_id dm_thin_dev_id(struct dm_thin_device *td); | |
120 | ||
121 | struct dm_thin_lookup_result { | |
122 | dm_block_t block; | |
17b7d63f | 123 | unsigned shared:1; |
991d9fa0 JT |
124 | }; |
125 | ||
126 | /* | |
127 | * Returns: | |
128 | * -EWOULDBLOCK iff @can_block is set and would block. | |
129 | * -ENODATA iff that mapping is not present. | |
130 | * 0 success | |
131 | */ | |
132 | int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, | |
133 | int can_block, struct dm_thin_lookup_result *result); | |
134 | ||
135 | /* | |
136 | * Obtain an unused block. | |
137 | */ | |
138 | int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result); | |
139 | ||
140 | /* | |
141 | * Insert or remove block. | |
142 | */ | |
143 | int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block, | |
144 | dm_block_t data_block); | |
145 | ||
146 | int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block); | |
147 | ||
148 | /* | |
149 | * Queries. | |
150 | */ | |
40db5a53 JT |
151 | bool dm_thin_changed_this_transaction(struct dm_thin_device *td); |
152 | ||
991d9fa0 JT |
153 | int dm_thin_get_highest_mapped_block(struct dm_thin_device *td, |
154 | dm_block_t *highest_mapped); | |
155 | ||
156 | int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result); | |
157 | ||
158 | int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, | |
159 | dm_block_t *result); | |
160 | ||
161 | int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd, | |
162 | dm_block_t *result); | |
163 | ||
164 | int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd, | |
165 | dm_block_t *result); | |
166 | ||
167 | int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result); | |
168 | ||
169 | int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result); | |
170 | ||
171 | /* | |
172 | * Returns -ENOSPC if the new size is too small and already allocated | |
173 | * blocks would be lost. | |
174 | */ | |
175 | int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size); | |
176 | ||
177 | /*----------------------------------------------------------------*/ | |
178 | ||
179 | #endif |