xref: /linux/drivers/md/dm-vdo/indexer/config.h (revision 40d269c000bda9fcd276a0412a9cebd3f6e344c5)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright 2023 Red Hat
4  */
5 
6 #ifndef UDS_CONFIG_H
7 #define UDS_CONFIG_H
8 
9 #include "geometry.h"
10 #include "indexer.h"
11 #include "io-factory.h"
12 
13 /*
14  * The uds_configuration records a variety of parameters used to configure a new UDS index. Some
15  * parameters are provided by the client, while others are fixed or derived from user-supplied
16  * values. It is created when an index is created, and it is recorded in the index metadata.
17  */
18 
19 enum {
20 	DEFAULT_VOLUME_INDEX_MEAN_DELTA = 4096,
21 	DEFAULT_CACHE_CHAPTERS = 7,
22 	DEFAULT_SPARSE_SAMPLE_RATE = 32,
23 	MAX_ZONES = 16,
24 };
25 
26 /* A set of configuration parameters for the indexer. */
27 struct uds_configuration {
28 	/* Storage device for the index */
29 	struct block_device *bdev;
30 
31 	/* The maximum allowable size of the index */
32 	size_t size;
33 
34 	/* The offset where the index should start */
35 	off_t offset;
36 
37 	/* Parameters for the volume */
38 
39 	/* The volume layout */
40 	struct index_geometry *geometry;
41 
42 	/* Index owner's nonce */
43 	u64 nonce;
44 
45 	/* The number of threads used to process index requests */
46 	unsigned int zone_count;
47 
48 	/* The number of threads used to read volume pages */
49 	unsigned int read_threads;
50 
51 	/* Size of the page cache and sparse chapter index cache in chapters */
52 	u32 cache_chapters;
53 
54 	/* Parameters for the volume index */
55 
56 	/* The mean delta for the volume index */
57 	u32 volume_index_mean_delta;
58 
59 	/* Sampling rate for sparse indexing */
60 	u32 sparse_sample_rate;
61 };
62 
63 /* On-disk structure of data for a version 8.02 index. */
64 struct uds_configuration_8_02 {
65 	/* Smaller (16), Small (64) or large (256) indices */
66 	u32 record_pages_per_chapter;
67 	/* Total number of chapters per volume */
68 	u32 chapters_per_volume;
69 	/* Number of sparse chapters per volume */
70 	u32 sparse_chapters_per_volume;
71 	/* Size of the page cache, in chapters */
72 	u32 cache_chapters;
73 	/* Unused field */
74 	u32 unused;
75 	/* The volume index mean delta to use */
76 	u32 volume_index_mean_delta;
77 	/* Size of a page, used for both record pages and index pages */
78 	u32 bytes_per_page;
79 	/* Sampling rate for sparse indexing */
80 	u32 sparse_sample_rate;
81 	/* Index owner's nonce */
82 	u64 nonce;
83 	/* Virtual chapter remapped from physical chapter 0 */
84 	u64 remapped_virtual;
85 	/* New physical chapter which remapped chapter was moved to */
86 	u64 remapped_physical;
87 } __packed;
88 
89 /* On-disk structure of data for a version 6.02 index. */
90 struct uds_configuration_6_02 {
91 	/* Smaller (16), Small (64) or large (256) indices */
92 	u32 record_pages_per_chapter;
93 	/* Total number of chapters per volume */
94 	u32 chapters_per_volume;
95 	/* Number of sparse chapters per volume */
96 	u32 sparse_chapters_per_volume;
97 	/* Size of the page cache, in chapters */
98 	u32 cache_chapters;
99 	/* Unused field */
100 	u32 unused;
101 	/* The volume index mean delta to use */
102 	u32 volume_index_mean_delta;
103 	/* Size of a page, used for both record pages and index pages */
104 	u32 bytes_per_page;
105 	/* Sampling rate for sparse indexing */
106 	u32 sparse_sample_rate;
107 	/* Index owner's nonce */
108 	u64 nonce;
109 } __packed;
110 
111 int __must_check uds_make_configuration(const struct uds_parameters *params,
112 					struct uds_configuration **config_ptr);
113 
114 void uds_free_configuration(struct uds_configuration *config);
115 
116 int __must_check uds_validate_config_contents(struct buffered_reader *reader,
117 					      struct uds_configuration *config);
118 
119 int __must_check uds_write_config_contents(struct buffered_writer *writer,
120 					   struct uds_configuration *config, u32 version);
121 
122 void uds_log_configuration(struct uds_configuration *config);
123 
124 #endif /* UDS_CONFIG_H */
125