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 */
141