xref: /linux/drivers/md/dm-vdo/indexer/chapter-index.h (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright 2023 Red Hat
4  */
5 
6 #ifndef UDS_CHAPTER_INDEX_H
7 #define UDS_CHAPTER_INDEX_H
8 
9 #include <linux/limits.h>
10 
11 #include "delta-index.h"
12 #include "geometry.h"
13 
14 /*
15  * A chapter index for an open chapter is a mutable structure that tracks all the records that have
16  * been added to the chapter. A chapter index for a closed chapter is similar except that it is
17  * immutable because the contents of a closed chapter can never change, and the immutable structure
18  * is more efficient. Both types of chapter index are implemented with a delta index.
19  */
20 
21 /* The value returned when no entry is found in the chapter index. */
22 #define NO_CHAPTER_INDEX_ENTRY U16_MAX
23 
24 struct open_chapter_index {
25 	const struct index_geometry *geometry;
26 	struct delta_index delta_index;
27 	u64 virtual_chapter_number;
28 	u64 volume_nonce;
29 	size_t memory_size;
30 };
31 
32 int __must_check uds_make_open_chapter_index(struct open_chapter_index **chapter_index,
33 					     const struct index_geometry *geometry,
34 					     u64 volume_nonce);
35 
36 void uds_free_open_chapter_index(struct open_chapter_index *chapter_index);
37 
38 void uds_empty_open_chapter_index(struct open_chapter_index *chapter_index,
39 				  u64 virtual_chapter_number);
40 
41 int __must_check uds_put_open_chapter_index_record(struct open_chapter_index *chapter_index,
42 						   const struct uds_record_name *name,
43 						   u32 page_number);
44 
45 int __must_check uds_pack_open_chapter_index_page(struct open_chapter_index *chapter_index,
46 						  u8 *memory, u32 first_list,
47 						  bool last_page, u32 *lists_packed);
48 
49 int __must_check uds_initialize_chapter_index_page(struct delta_index_page *index_page,
50 						   const struct index_geometry *geometry,
51 						   u8 *page_buffer, u64 volume_nonce);
52 
53 int __must_check uds_validate_chapter_index_page(const struct delta_index_page *index_page,
54 						 const struct index_geometry *geometry);
55 
56 int __must_check uds_search_chapter_index_page(struct delta_index_page *index_page,
57 					       const struct index_geometry *geometry,
58 					       const struct uds_record_name *name,
59 					       u16 *record_page_ptr);
60 
61 #endif /* UDS_CHAPTER_INDEX_H */
62