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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" | |
ac8c3f3d | 11 | #include "persistent-data/dm-space-map.h" |
991d9fa0 JT |
12 | |
13 | #define THIN_METADATA_BLOCK_SIZE 4096 | |
14 | ||
c4a69ecd MS |
15 | /* |
16 | * The metadata device is currently limited in size. | |
17 | * | |
18 | * We have one block of index, which can hold 255 index entries. Each | |
19 | * index entry contains allocation info about 16k metadata blocks. | |
20 | */ | |
21 | #define THIN_METADATA_MAX_SECTORS (255 * (1 << 14) * (THIN_METADATA_BLOCK_SIZE / (1 << SECTOR_SHIFT))) | |
22 | ||
23 | /* | |
24 | * A metadata device larger than 16GB triggers a warning. | |
25 | */ | |
26 | #define THIN_METADATA_MAX_SECTORS_WARNING (16 * (1024 * 1024 * 1024 >> SECTOR_SHIFT)) | |
27 | ||
991d9fa0 JT |
28 | /*----------------------------------------------------------------*/ |
29 | ||
30 | struct dm_pool_metadata; | |
31 | struct dm_thin_device; | |
32 | ||
33 | /* | |
34 | * Device identifier | |
35 | */ | |
36 | typedef uint64_t dm_thin_id; | |
37 | ||
38 | /* | |
39 | * Reopens or creates a new, empty metadata volume. | |
40 | */ | |
41 | struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, | |
66b1edc0 JT |
42 | sector_t data_block_size, |
43 | bool format_device); | |
991d9fa0 JT |
44 | |
45 | int dm_pool_metadata_close(struct dm_pool_metadata *pmd); | |
46 | ||
47 | /* | |
48 | * Compat feature flags. Any incompat flags beyond the ones | |
49 | * specified below will prevent use of the thin metadata. | |
50 | */ | |
51 | #define THIN_FEATURE_COMPAT_SUPP 0UL | |
52 | #define THIN_FEATURE_COMPAT_RO_SUPP 0UL | |
53 | #define THIN_FEATURE_INCOMPAT_SUPP 0UL | |
54 | ||
55 | /* | |
56 | * Device creation/deletion. | |
57 | */ | |
58 | int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev); | |
59 | ||
60 | /* | |
61 | * An internal snapshot. | |
62 | * | |
63 | * You can only snapshot a quiesced origin i.e. one that is either | |
64 | * suspended or not instanced at all. | |
65 | */ | |
66 | int dm_pool_create_snap(struct dm_pool_metadata *pmd, dm_thin_id dev, | |
67 | dm_thin_id origin); | |
68 | ||
69 | /* | |
70 | * Deletes a virtual device from the metadata. It _is_ safe to call this | |
71 | * when that device is open. Operations on that device will just start | |
72 | * failing. You still need to call close() on the device. | |
73 | */ | |
74 | int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd, | |
75 | dm_thin_id dev); | |
76 | ||
77 | /* | |
78 | * Commits _all_ metadata changes: device creation, deletion, mapping | |
79 | * updates. | |
80 | */ | |
81 | int dm_pool_commit_metadata(struct dm_pool_metadata *pmd); | |
82 | ||
da105ed5 JT |
83 | /* |
84 | * Discards all uncommitted changes. Rereads the superblock, rolling back | |
85 | * to the last good transaction. Thin devices remain open. | |
86 | * dm_thin_aborted_changes() tells you if they had uncommitted changes. | |
87 | * | |
88 | * If this call fails it's only useful to call dm_pool_metadata_close(). | |
89 | * All other methods will fail with -EINVAL. | |
90 | */ | |
91 | int dm_pool_abort_metadata(struct dm_pool_metadata *pmd); | |
92 | ||
991d9fa0 JT |
93 | /* |
94 | * Set/get userspace transaction id. | |
95 | */ | |
96 | int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd, | |
97 | uint64_t current_id, | |
98 | uint64_t new_id); | |
99 | ||
100 | int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd, | |
101 | uint64_t *result); | |
102 | ||
103 | /* | |
104 | * Hold/get root for userspace transaction. | |
cc8394d8 JT |
105 | * |
106 | * The metadata snapshot is a copy of the current superblock (minus the | |
107 | * space maps). Userland can access the data structures for READ | |
108 | * operations only. A small performance hit is incurred by providing this | |
109 | * copy of the metadata to userland due to extra copy-on-write operations | |
110 | * on the metadata nodes. Release this as soon as you finish with it. | |
991d9fa0 | 111 | */ |
cc8394d8 JT |
112 | int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd); |
113 | int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd); | |
991d9fa0 | 114 | |
cc8394d8 JT |
115 | int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd, |
116 | dm_block_t *result); | |
991d9fa0 JT |
117 | |
118 | /* | |
119 | * Actions on a single virtual device. | |
120 | */ | |
121 | ||
122 | /* | |
123 | * Opening the same device more than once will fail with -EBUSY. | |
124 | */ | |
125 | int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev, | |
126 | struct dm_thin_device **td); | |
127 | ||
128 | int dm_pool_close_thin_device(struct dm_thin_device *td); | |
129 | ||
130 | dm_thin_id dm_thin_dev_id(struct dm_thin_device *td); | |
131 | ||
132 | struct dm_thin_lookup_result { | |
133 | dm_block_t block; | |
17b7d63f | 134 | unsigned shared:1; |
991d9fa0 JT |
135 | }; |
136 | ||
137 | /* | |
138 | * Returns: | |
139 | * -EWOULDBLOCK iff @can_block is set and would block. | |
140 | * -ENODATA iff that mapping is not present. | |
141 | * 0 success | |
142 | */ | |
143 | int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, | |
144 | int can_block, struct dm_thin_lookup_result *result); | |
145 | ||
146 | /* | |
147 | * Obtain an unused block. | |
148 | */ | |
149 | int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result); | |
150 | ||
151 | /* | |
152 | * Insert or remove block. | |
153 | */ | |
154 | int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block, | |
155 | dm_block_t data_block); | |
156 | ||
157 | int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block); | |
158 | ||
159 | /* | |
160 | * Queries. | |
161 | */ | |
40db5a53 JT |
162 | bool dm_thin_changed_this_transaction(struct dm_thin_device *td); |
163 | ||
da105ed5 JT |
164 | bool dm_thin_aborted_changes(struct dm_thin_device *td); |
165 | ||
991d9fa0 JT |
166 | int dm_thin_get_highest_mapped_block(struct dm_thin_device *td, |
167 | dm_block_t *highest_mapped); | |
168 | ||
169 | int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result); | |
170 | ||
171 | int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, | |
172 | dm_block_t *result); | |
173 | ||
174 | int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd, | |
175 | dm_block_t *result); | |
176 | ||
177 | int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd, | |
178 | dm_block_t *result); | |
179 | ||
180 | int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result); | |
181 | ||
182 | int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result); | |
183 | ||
184 | /* | |
185 | * Returns -ENOSPC if the new size is too small and already allocated | |
186 | * blocks would be lost. | |
187 | */ | |
188 | int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size); | |
24347e95 | 189 | int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_size); |
991d9fa0 | 190 | |
12ba58af JT |
191 | /* |
192 | * Flicks the underlying block manager into read only mode, so you know | |
193 | * that nothing is changing. | |
194 | */ | |
195 | void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd); | |
196 | ||
ac8c3f3d JT |
197 | int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd, |
198 | dm_block_t threshold, | |
199 | dm_sm_threshold_fn fn, | |
200 | void *context); | |
201 | ||
991d9fa0 JT |
202 | /*----------------------------------------------------------------*/ |
203 | ||
204 | #endif |