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7#include "dm-bitset.h"
8#include "dm-transaction-manager.h"
9
10#include <linux/export.h>
11#include <linux/device-mapper.h>
12
13#define DM_MSG_PREFIX "bitset"
14#define BITS_PER_ARRAY_ENTRY 64
15
16
17
18static struct dm_btree_value_type bitset_bvt = {
19 .context = NULL,
20 .size = sizeof(__le64),
21 .inc = NULL,
22 .dec = NULL,
23 .equal = NULL,
24};
25
26
27
28void dm_disk_bitset_init(struct dm_transaction_manager *tm,
29 struct dm_disk_bitset *info)
30{
31 dm_array_info_init(&info->array_info, tm, &bitset_bvt);
32 info->current_index_set = false;
33}
34EXPORT_SYMBOL_GPL(dm_disk_bitset_init);
35
36int dm_bitset_empty(struct dm_disk_bitset *info, dm_block_t *root)
37{
38 return dm_array_empty(&info->array_info, root);
39}
40EXPORT_SYMBOL_GPL(dm_bitset_empty);
41
42int dm_bitset_resize(struct dm_disk_bitset *info, dm_block_t root,
43 uint32_t old_nr_entries, uint32_t new_nr_entries,
44 bool default_value, dm_block_t *new_root)
45{
46 uint32_t old_blocks = dm_div_up(old_nr_entries, BITS_PER_ARRAY_ENTRY);
47 uint32_t new_blocks = dm_div_up(new_nr_entries, BITS_PER_ARRAY_ENTRY);
48 __le64 value = default_value ? cpu_to_le64(~0) : cpu_to_le64(0);
49
50 __dm_bless_for_disk(&value);
51 return dm_array_resize(&info->array_info, root, old_blocks, new_blocks,
52 &value, new_root);
53}
54EXPORT_SYMBOL_GPL(dm_bitset_resize);
55
56int dm_bitset_del(struct dm_disk_bitset *info, dm_block_t root)
57{
58 return dm_array_del(&info->array_info, root);
59}
60EXPORT_SYMBOL_GPL(dm_bitset_del);
61
62int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root,
63 dm_block_t *new_root)
64{
65 int r;
66 __le64 value;
67
68 if (!info->current_index_set || !info->dirty)
69 return 0;
70
71 value = cpu_to_le64(info->current_bits);
72
73 __dm_bless_for_disk(&value);
74 r = dm_array_set_value(&info->array_info, root, info->current_index,
75 &value, new_root);
76 if (r)
77 return r;
78
79 info->current_index_set = false;
80 info->dirty = false;
81
82 return 0;
83}
84EXPORT_SYMBOL_GPL(dm_bitset_flush);
85
86static int read_bits(struct dm_disk_bitset *info, dm_block_t root,
87 uint32_t array_index)
88{
89 int r;
90 __le64 value;
91
92 r = dm_array_get_value(&info->array_info, root, array_index, &value);
93 if (r)
94 return r;
95
96 info->current_bits = le64_to_cpu(value);
97 info->current_index_set = true;
98 info->current_index = array_index;
99 info->dirty = false;
100
101 return 0;
102}
103
104static int get_array_entry(struct dm_disk_bitset *info, dm_block_t root,
105 uint32_t index, dm_block_t *new_root)
106{
107 int r;
108 unsigned array_index = index / BITS_PER_ARRAY_ENTRY;
109
110 if (info->current_index_set) {
111 if (info->current_index == array_index)
112 return 0;
113
114 r = dm_bitset_flush(info, root, new_root);
115 if (r)
116 return r;
117 }
118
119 return read_bits(info, root, array_index);
120}
121
122int dm_bitset_set_bit(struct dm_disk_bitset *info, dm_block_t root,
123 uint32_t index, dm_block_t *new_root)
124{
125 int r;
126 unsigned b = index % BITS_PER_ARRAY_ENTRY;
127
128 r = get_array_entry(info, root, index, new_root);
129 if (r)
130 return r;
131
132 set_bit(b, (unsigned long *) &info->current_bits);
133 info->dirty = true;
134
135 return 0;
136}
137EXPORT_SYMBOL_GPL(dm_bitset_set_bit);
138
139int dm_bitset_clear_bit(struct dm_disk_bitset *info, dm_block_t root,
140 uint32_t index, dm_block_t *new_root)
141{
142 int r;
143 unsigned b = index % BITS_PER_ARRAY_ENTRY;
144
145 r = get_array_entry(info, root, index, new_root);
146 if (r)
147 return r;
148
149 clear_bit(b, (unsigned long *) &info->current_bits);
150 info->dirty = true;
151
152 return 0;
153}
154EXPORT_SYMBOL_GPL(dm_bitset_clear_bit);
155
156int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root,
157 uint32_t index, dm_block_t *new_root, bool *result)
158{
159 int r;
160 unsigned b = index % BITS_PER_ARRAY_ENTRY;
161
162 r = get_array_entry(info, root, index, new_root);
163 if (r)
164 return r;
165
166 *result = test_bit(b, (unsigned long *) &info->current_bits);
167 return 0;
168}
169EXPORT_SYMBOL_GPL(dm_bitset_test_bit);
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172
