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Joe Thornber3241b1d2011-10-31 20:19:11 +00001/*
2 * Copyright (C) 2011 Red Hat, Inc.
3 *
4 * This file is released under the GPL.
5 */
6
7#ifndef DM_BTREE_INTERNAL_H
8#define DM_BTREE_INTERNAL_H
9
10#include "dm-btree.h"
11
12/*----------------------------------------------------------------*/
13
14/*
15 * We'll need 2 accessor functions for n->csum and n->blocknr
16 * to support dm-btree-spine.c in that case.
17 */
18
19enum node_flags {
20 INTERNAL_NODE = 1,
21 LEAF_NODE = 1 << 1
22};
23
24/*
25 * Every btree node begins with this structure. Make sure it's a multiple
26 * of 8-bytes in size, otherwise the 64bit keys will be mis-aligned.
27 */
28struct node_header {
29 __le32 csum;
30 __le32 flags;
31 __le64 blocknr; /* Block this node is supposed to live in. */
32
33 __le32 nr_entries;
34 __le32 max_entries;
35 __le32 value_size;
36 __le32 padding;
37} __packed;
38
Mikulas Patocka550929f2012-12-21 20:23:30 +000039struct btree_node {
Joe Thornber3241b1d2011-10-31 20:19:11 +000040 struct node_header header;
41 __le64 keys[0];
42} __packed;
43
44
Joe Thornber9b460d32014-11-10 15:03:24 +000045/*
46 * Locks a block using the btree node validator.
47 */
48int bn_read_lock(struct dm_btree_info *info, dm_block_t b,
49 struct dm_block **result);
50
Mikulas Patocka550929f2012-12-21 20:23:30 +000051void inc_children(struct dm_transaction_manager *tm, struct btree_node *n,
Joe Thornber3241b1d2011-10-31 20:19:11 +000052 struct dm_btree_value_type *vt);
53
54int new_block(struct dm_btree_info *info, struct dm_block **result);
Mikulas Patocka4c7da062015-10-22 16:46:59 -040055void unlock_block(struct dm_btree_info *info, struct dm_block *b);
Joe Thornber3241b1d2011-10-31 20:19:11 +000056
57/*
58 * Spines keep track of the rolling locks. There are 2 variants, read-only
59 * and one that uses shadowing. These are separate structs to allow the
60 * type checker to spot misuse, for example accidentally calling read_lock
61 * on a shadow spine.
62 */
63struct ro_spine {
64 struct dm_btree_info *info;
65
66 int count;
67 struct dm_block *nodes[2];
68};
69
70void init_ro_spine(struct ro_spine *s, struct dm_btree_info *info);
71int exit_ro_spine(struct ro_spine *s);
72int ro_step(struct ro_spine *s, dm_block_t new_child);
Joe Thornber4e7f1f92013-03-01 22:45:50 +000073void ro_pop(struct ro_spine *s);
Mikulas Patocka550929f2012-12-21 20:23:30 +000074struct btree_node *ro_node(struct ro_spine *s);
Joe Thornber3241b1d2011-10-31 20:19:11 +000075
76struct shadow_spine {
77 struct dm_btree_info *info;
78
79 int count;
80 struct dm_block *nodes[2];
81
82 dm_block_t root;
83};
84
85void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info);
86int exit_shadow_spine(struct shadow_spine *s);
87
88int shadow_step(struct shadow_spine *s, dm_block_t b,
89 struct dm_btree_value_type *vt);
90
91/*
92 * The spine must have at least one entry before calling this.
93 */
94struct dm_block *shadow_current(struct shadow_spine *s);
95
96/*
97 * The spine must have at least two entries before calling this.
98 */
99struct dm_block *shadow_parent(struct shadow_spine *s);
100
101int shadow_has_parent(struct shadow_spine *s);
102
103int shadow_root(struct shadow_spine *s);
104
105/*
106 * Some inlines.
107 */
Mikulas Patocka550929f2012-12-21 20:23:30 +0000108static inline __le64 *key_ptr(struct btree_node *n, uint32_t index)
Joe Thornber3241b1d2011-10-31 20:19:11 +0000109{
110 return n->keys + index;
111}
112
Mikulas Patocka550929f2012-12-21 20:23:30 +0000113static inline void *value_base(struct btree_node *n)
Joe Thornber3241b1d2011-10-31 20:19:11 +0000114{
115 return &n->keys[le32_to_cpu(n->header.max_entries)];
116}
117
Mikulas Patocka550929f2012-12-21 20:23:30 +0000118static inline void *value_ptr(struct btree_node *n, uint32_t index)
Joe Thornber3241b1d2011-10-31 20:19:11 +0000119{
Joe Thornbera3aefb32012-03-28 18:41:25 +0100120 uint32_t value_size = le32_to_cpu(n->header.value_size);
Joe Thornber3241b1d2011-10-31 20:19:11 +0000121 return value_base(n) + (value_size * index);
122}
123
124/*
125 * Assumes the values are suitably-aligned and converts to core format.
126 */
Mikulas Patocka550929f2012-12-21 20:23:30 +0000127static inline uint64_t value64(struct btree_node *n, uint32_t index)
Joe Thornber3241b1d2011-10-31 20:19:11 +0000128{
129 __le64 *values_le = value_base(n);
130
131 return le64_to_cpu(values_le[index]);
132}
133
134/*
135 * Searching for a key within a single node.
136 */
Mikulas Patocka550929f2012-12-21 20:23:30 +0000137int lower_bound(struct btree_node *n, uint64_t key);
Joe Thornber3241b1d2011-10-31 20:19:11 +0000138
139extern struct dm_block_validator btree_node_validator;
140
Joe Thornberb0dc3c82015-08-12 15:12:09 +0100141/*
142 * Value type for upper levels of multi-level btrees.
143 */
144extern void init_le64_type(struct dm_transaction_manager *tm,
145 struct dm_btree_value_type *vt);
146
Joe Thornber3241b1d2011-10-31 20:19:11 +0000147#endif /* DM_BTREE_INTERNAL_H */