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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 | ||
da105ed5 JT |
82 | /* |
83 | * Discards all uncommitted changes. Rereads the superblock, rolling back | |
84 | * to the last good transaction. Thin devices remain open. | |
85 | * dm_thin_aborted_changes() tells you if they had uncommitted changes. | |
86 | * | |
87 | * If this call fails it's only useful to call dm_pool_metadata_close(). | |
88 | * All other methods will fail with -EINVAL. | |
89 | */ | |
90 | int dm_pool_abort_metadata(struct dm_pool_metadata *pmd); | |
91 | ||
991d9fa0 JT |
92 | /* |
93 | * Set/get userspace transaction id. | |
94 | */ | |
95 | int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd, | |
96 | uint64_t current_id, | |
97 | uint64_t new_id); | |
98 | ||
99 | int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd, | |
100 | uint64_t *result); | |
101 | ||
102 | /* | |
103 | * Hold/get root for userspace transaction. | |
cc8394d8 JT |
104 | * |
105 | * The metadata snapshot is a copy of the current superblock (minus the | |
106 | * space maps). Userland can access the data structures for READ | |
107 | * operations only. A small performance hit is incurred by providing this | |
108 | * copy of the metadata to userland due to extra copy-on-write operations | |
109 | * on the metadata nodes. Release this as soon as you finish with it. | |
991d9fa0 | 110 | */ |
cc8394d8 JT |
111 | int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd); |
112 | int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd); | |
991d9fa0 | 113 | |
cc8394d8 JT |
114 | int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd, |
115 | dm_block_t *result); | |
991d9fa0 JT |
116 | |
117 | /* | |
118 | * Actions on a single virtual device. | |
119 | */ | |
120 | ||
121 | /* | |
122 | * Opening the same device more than once will fail with -EBUSY. | |
123 | */ | |
124 | int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev, | |
125 | struct dm_thin_device **td); | |
126 | ||
127 | int dm_pool_close_thin_device(struct dm_thin_device *td); | |
128 | ||
129 | dm_thin_id dm_thin_dev_id(struct dm_thin_device *td); | |
130 | ||
131 | struct dm_thin_lookup_result { | |
132 | dm_block_t block; | |
17b7d63f | 133 | unsigned shared:1; |
991d9fa0 JT |
134 | }; |
135 | ||
136 | /* | |
137 | * Returns: | |
138 | * -EWOULDBLOCK iff @can_block is set and would block. | |
139 | * -ENODATA iff that mapping is not present. | |
140 | * 0 success | |
141 | */ | |
142 | int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, | |
143 | int can_block, struct dm_thin_lookup_result *result); | |
144 | ||
145 | /* | |
146 | * Obtain an unused block. | |
147 | */ | |
148 | int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result); | |
149 | ||
150 | /* | |
151 | * Insert or remove block. | |
152 | */ | |
153 | int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block, | |
154 | dm_block_t data_block); | |
155 | ||
156 | int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block); | |
157 | ||
158 | /* | |
159 | * Queries. | |
160 | */ | |
40db5a53 JT |
161 | bool dm_thin_changed_this_transaction(struct dm_thin_device *td); |
162 | ||
da105ed5 JT |
163 | bool dm_thin_aborted_changes(struct dm_thin_device *td); |
164 | ||
991d9fa0 JT |
165 | int dm_thin_get_highest_mapped_block(struct dm_thin_device *td, |
166 | dm_block_t *highest_mapped); | |
167 | ||
168 | int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result); | |
169 | ||
170 | int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, | |
171 | dm_block_t *result); | |
172 | ||
173 | int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd, | |
174 | dm_block_t *result); | |
175 | ||
176 | int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd, | |
177 | dm_block_t *result); | |
178 | ||
179 | int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result); | |
180 | ||
181 | int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result); | |
182 | ||
183 | /* | |
184 | * Returns -ENOSPC if the new size is too small and already allocated | |
185 | * blocks would be lost. | |
186 | */ | |
187 | int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size); | |
188 | ||
12ba58af JT |
189 | /* |
190 | * Flicks the underlying block manager into read only mode, so you know | |
191 | * that nothing is changing. | |
192 | */ | |
193 | void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd); | |
194 | ||
991d9fa0 JT |
195 | /*----------------------------------------------------------------*/ |
196 | ||
197 | #endif |