drivers/md/dm-vdo/indexer/config.h

   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 */