1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * Copyright 2023 Red Hat
  4 */
  5
  6#ifndef UDS_INDEX_GEOMETRY_H
  7#define UDS_INDEX_GEOMETRY_H
  8
  9#include "indexer.h"
 10
 11/*
 12 * The index_geometry records parameters that define the layout of a UDS index volume, and the size and
 13 * shape of various index structures. It is created when the index is created, and is referenced by
 14 * many index sub-components.
 15 */
 16
 17struct index_geometry {
 18	/* Size of a chapter page, in bytes */
 19	size_t bytes_per_page;
 20	/* Number of record pages in a chapter */
 21	u32 record_pages_per_chapter;
 22	/* Total number of chapters in a volume */
 23	u32 chapters_per_volume;
 24	/* Number of sparsely-indexed chapters in a volume */
 25	u32 sparse_chapters_per_volume;
 26	/* Number of bits used to determine delta list numbers */
 27	u8 chapter_delta_list_bits;
 28	/* Virtual chapter remapped from physical chapter 0 */
 29	u64 remapped_virtual;
 30	/* New physical chapter where the remapped chapter can be found */
 31	u64 remapped_physical;
 32
 33	/*
 34	 * The following properties are derived from the ones above, but they are computed and
 35	 * recorded as fields for convenience.
 36	 */
 37	/* Total number of pages in a volume, excluding the header */
 38	u32 pages_per_volume;
 39	/* Total number of bytes in a volume, including the header */
 40	size_t bytes_per_volume;
 41	/* Number of pages in a chapter */
 42	u32 pages_per_chapter;
 43	/* Number of index pages in a chapter index */
 44	u32 index_pages_per_chapter;
 45	/* Number of records that fit on a page */
 46	u32 records_per_page;
 47	/* Number of records that fit in a chapter */
 48	u32 records_per_chapter;
 49	/* Number of records that fit in a volume */
 50	u64 records_per_volume;
 51	/* Number of delta lists per chapter index */
 52	u32 delta_lists_per_chapter;
 53	/* Mean delta for chapter indexes */
 54	u32 chapter_mean_delta;
 55	/* Number of bits needed for record page numbers */
 56	u8 chapter_payload_bits;
 57	/* Number of bits used to compute addresses for chapter delta lists */
 58	u8 chapter_address_bits;
 59	/* Number of densely-indexed chapters in a volume */
 60	u32 dense_chapters_per_volume;
 61};
 62
 63enum {
 64	/* The number of bytes in a record (name + metadata) */
 65	BYTES_PER_RECORD = (UDS_RECORD_NAME_SIZE + UDS_RECORD_DATA_SIZE),
 66
 67	/* The default length of a page in a chapter, in bytes */
 68	DEFAULT_BYTES_PER_PAGE = 1024 * BYTES_PER_RECORD,
 69
 70	/* The default maximum number of records per page */
 71	DEFAULT_RECORDS_PER_PAGE = DEFAULT_BYTES_PER_PAGE / BYTES_PER_RECORD,
 72
 73	/* The default number of record pages in a chapter */
 74	DEFAULT_RECORD_PAGES_PER_CHAPTER = 256,
 75
 76	/* The default number of record pages in a chapter for a small index */
 77	SMALL_RECORD_PAGES_PER_CHAPTER = 64,
 78
 79	/* The default number of chapters in a volume */
 80	DEFAULT_CHAPTERS_PER_VOLUME = 1024,
 81
 82	/* The default number of sparsely-indexed chapters in a volume */
 83	DEFAULT_SPARSE_CHAPTERS_PER_VOLUME = 0,
 84
 85	/* The log2 of the default mean delta */
 86	DEFAULT_CHAPTER_MEAN_DELTA_BITS = 16,
 87
 88	/* The log2 of the number of delta lists in a large chapter */
 89	DEFAULT_CHAPTER_DELTA_LIST_BITS = 12,
 90
 91	/* The log2 of the number of delta lists in a small chapter */
 92	SMALL_CHAPTER_DELTA_LIST_BITS = 10,
 93
 94	/* The number of header pages per volume */
 95	HEADER_PAGES_PER_VOLUME = 1,
 96};
 97
 98int __must_check uds_make_index_geometry(size_t bytes_per_page, u32 record_pages_per_chapter,
 99					 u32 chapters_per_volume,
100					 u32 sparse_chapters_per_volume, u64 remapped_virtual,
101					 u64 remapped_physical,
102					 struct index_geometry **geometry_ptr);
103
104int __must_check uds_copy_index_geometry(struct index_geometry *source,
105					 struct index_geometry **geometry_ptr);
106
107void uds_free_index_geometry(struct index_geometry *geometry);
108
109u32 __must_check uds_map_to_physical_chapter(const struct index_geometry *geometry,
110					     u64 virtual_chapter);
111
112/*
113 * Check whether this geometry is reduced by a chapter. This will only be true if the volume was
114 * converted from a non-lvm volume to an lvm volume.
115 */
116static inline bool __must_check
117uds_is_reduced_index_geometry(const struct index_geometry *geometry)
118{
119	return !!(geometry->chapters_per_volume & 1);
120}
121
122static inline bool __must_check
123uds_is_sparse_index_geometry(const struct index_geometry *geometry)
124{
125	return geometry->sparse_chapters_per_volume > 0;
126}
127
128bool __must_check uds_has_sparse_chapters(const struct index_geometry *geometry,
129					  u64 oldest_virtual_chapter,
130					  u64 newest_virtual_chapter);
131
132bool __must_check uds_is_chapter_sparse(const struct index_geometry *geometry,
133					u64 oldest_virtual_chapter,
134					u64 newest_virtual_chapter,
135					u64 virtual_chapter_number);
136
137u32 __must_check uds_chapters_to_expire(const struct index_geometry *geometry,
138					u64 newest_chapter);
139
140#endif /* UDS_INDEX_GEOMETRY_H */