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c6b4fcba JT |
1 | /* |
2 | * Copyright (C) 2012 Red Hat, Inc. | |
3 | * | |
4 | * This file is released under the GPL. | |
5 | */ | |
6 | ||
7 | #ifndef DM_CACHE_METADATA_H | |
8 | #define DM_CACHE_METADATA_H | |
9 | ||
10 | #include "dm-cache-block-types.h" | |
11 | #include "dm-cache-policy-internal.h" | |
895b47d7 | 12 | #include "persistent-data/dm-space-map-metadata.h" |
c6b4fcba JT |
13 | |
14 | /*----------------------------------------------------------------*/ | |
15 | ||
895b47d7 | 16 | #define DM_CACHE_METADATA_BLOCK_SIZE DM_SM_METADATA_BLOCK_SIZE |
c6b4fcba JT |
17 | |
18 | /* FIXME: remove this restriction */ | |
19 | /* | |
20 | * The metadata device is currently limited in size. | |
c6b4fcba | 21 | */ |
895b47d7 | 22 | #define DM_CACHE_METADATA_MAX_SECTORS DM_SM_METADATA_MAX_SECTORS |
c6b4fcba JT |
23 | |
24 | /* | |
25 | * A metadata device larger than 16GB triggers a warning. | |
26 | */ | |
27 | #define DM_CACHE_METADATA_MAX_SECTORS_WARNING (16 * (1024 * 1024 * 1024 >> SECTOR_SHIFT)) | |
28 | ||
29 | /*----------------------------------------------------------------*/ | |
30 | ||
31 | /* | |
32 | * Ext[234]-style compat feature flags. | |
33 | * | |
34 | * A new feature which old metadata will still be compatible with should | |
35 | * define a DM_CACHE_FEATURE_COMPAT_* flag (rarely useful). | |
36 | * | |
37 | * A new feature that is not compatible with old code should define a | |
38 | * DM_CACHE_FEATURE_INCOMPAT_* flag and guard the relevant code with | |
39 | * that flag. | |
40 | * | |
41 | * A new feature that is not compatible with old code accessing the | |
42 | * metadata RDWR should define a DM_CACHE_FEATURE_RO_COMPAT_* flag and | |
43 | * guard the relevant code with that flag. | |
44 | * | |
45 | * As these various flags are defined they should be added to the | |
46 | * following masks. | |
47 | */ | |
48 | #define DM_CACHE_FEATURE_COMPAT_SUPP 0UL | |
49 | #define DM_CACHE_FEATURE_COMPAT_RO_SUPP 0UL | |
50 | #define DM_CACHE_FEATURE_INCOMPAT_SUPP 0UL | |
51 | ||
52 | /* | |
53 | * Reopens or creates a new, empty metadata volume. | |
54 | * Returns an ERR_PTR on failure. | |
55 | */ | |
56 | struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev, | |
57 | sector_t data_block_size, | |
58 | bool may_format_device, | |
59 | size_t policy_hint_size); | |
60 | ||
61 | void dm_cache_metadata_close(struct dm_cache_metadata *cmd); | |
62 | ||
63 | /* | |
64 | * The metadata needs to know how many cache blocks there are. We don't | |
65 | * care about the origin, assuming the core target is giving us valid | |
66 | * origin blocks to map to. | |
67 | */ | |
68 | int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size); | |
69 | dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd); | |
70 | ||
71 | int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd, | |
72 | sector_t discard_block_size, | |
1bad9bc4 | 73 | dm_dblock_t new_nr_entries); |
c6b4fcba JT |
74 | |
75 | typedef int (*load_discard_fn)(void *context, sector_t discard_block_size, | |
1bad9bc4 | 76 | dm_dblock_t dblock, bool discarded); |
c6b4fcba JT |
77 | int dm_cache_load_discards(struct dm_cache_metadata *cmd, |
78 | load_discard_fn fn, void *context); | |
79 | ||
1bad9bc4 | 80 | int dm_cache_set_discard(struct dm_cache_metadata *cmd, dm_dblock_t dblock, bool discard); |
c6b4fcba JT |
81 | |
82 | int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock); | |
83 | int dm_cache_insert_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock, dm_oblock_t oblock); | |
84 | int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd); | |
85 | ||
86 | typedef int (*load_mapping_fn)(void *context, dm_oblock_t oblock, | |
87 | dm_cblock_t cblock, bool dirty, | |
88 | uint32_t hint, bool hint_valid); | |
89 | int dm_cache_load_mappings(struct dm_cache_metadata *cmd, | |
ea2dd8c1 | 90 | struct dm_cache_policy *policy, |
c6b4fcba JT |
91 | load_mapping_fn fn, |
92 | void *context); | |
93 | ||
94 | int dm_cache_set_dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty); | |
95 | ||
96 | struct dm_cache_statistics { | |
97 | uint32_t read_hits; | |
98 | uint32_t read_misses; | |
99 | uint32_t write_hits; | |
100 | uint32_t write_misses; | |
101 | }; | |
102 | ||
103 | void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd, | |
104 | struct dm_cache_statistics *stats); | |
028ae9f7 JT |
105 | |
106 | /* | |
107 | * 'void' because it's no big deal if it fails. | |
108 | */ | |
c6b4fcba JT |
109 | void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd, |
110 | struct dm_cache_statistics *stats); | |
111 | ||
112 | int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown); | |
113 | ||
114 | int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd, | |
115 | dm_block_t *result); | |
116 | ||
117 | int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd, | |
118 | dm_block_t *result); | |
119 | ||
120 | void dm_cache_dump(struct dm_cache_metadata *cmd); | |
121 | ||
122 | /* | |
123 | * The policy is invited to save a 32bit hint value for every cblock (eg, | |
124 | * for a hit count). These are stored against the policy name. If | |
125 | * policies are changed, then hints will be lost. If the machine crashes, | |
126 | * hints will be lost. | |
127 | * | |
128 | * The hints are indexed by the cblock, but many policies will not | |
129 | * neccessarily have a fast way of accessing efficiently via cblock. So | |
130 | * rather than querying the policy for each cblock, we let it walk its data | |
131 | * structures and fill in the hints in whatever order it wishes. | |
132 | */ | |
0596661f | 133 | int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *p); |
c6b4fcba | 134 | |
2ee57d58 JT |
135 | /* |
136 | * Query method. Are all the blocks in the cache clean? | |
137 | */ | |
138 | int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result); | |
139 | ||
028ae9f7 JT |
140 | bool dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd); |
141 | int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd); | |
142 | void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd); | |
143 | void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd); | |
144 | int dm_cache_metadata_abort(struct dm_cache_metadata *cmd); | |
145 | ||
c6b4fcba JT |
146 | /*----------------------------------------------------------------*/ |
147 | ||
148 | #endif /* DM_CACHE_METADATA_H */ |