1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2012 Red Hat, Inc.
5 * This file is released under the GPL.
9 #include "dm-transaction-manager.h"
11 #include <linux/export.h>
12 #include <linux/device-mapper.h>
14 #define DM_MSG_PREFIX "bitset"
15 #define BITS_PER_ARRAY_ENTRY 64
17 /*----------------------------------------------------------------*/
19 static struct dm_btree_value_type bitset_bvt = {
21 .size = sizeof(__le64),
27 /*----------------------------------------------------------------*/
29 void dm_disk_bitset_init(struct dm_transaction_manager *tm,
30 struct dm_disk_bitset *info)
32 dm_array_info_init(&info->array_info, tm, &bitset_bvt);
33 info->current_index_set = false;
35 EXPORT_SYMBOL_GPL(dm_disk_bitset_init);
37 int dm_bitset_empty(struct dm_disk_bitset *info, dm_block_t *root)
39 return dm_array_empty(&info->array_info, root);
41 EXPORT_SYMBOL_GPL(dm_bitset_empty);
43 struct packer_context {
49 static int pack_bits(uint32_t index, void *value, void *context)
52 struct packer_context *p = context;
53 unsigned int bit, nr = min(64u, p->nr_bits - (index * 64));
57 for (bit = 0; bit < nr; bit++) {
58 r = p->fn(index * 64 + bit, &bv, p->context);
63 set_bit(bit, (unsigned long *) &word);
65 clear_bit(bit, (unsigned long *) &word);
68 *((__le64 *) value) = cpu_to_le64(word);
73 int dm_bitset_new(struct dm_disk_bitset *info, dm_block_t *root,
74 uint32_t size, bit_value_fn fn, void *context)
76 struct packer_context p;
82 return dm_array_new(&info->array_info, root, dm_div_up(size, 64), pack_bits, &p);
84 EXPORT_SYMBOL_GPL(dm_bitset_new);
86 int dm_bitset_resize(struct dm_disk_bitset *info, dm_block_t root,
87 uint32_t old_nr_entries, uint32_t new_nr_entries,
88 bool default_value, dm_block_t *new_root)
90 uint32_t old_blocks = dm_div_up(old_nr_entries, BITS_PER_ARRAY_ENTRY);
91 uint32_t new_blocks = dm_div_up(new_nr_entries, BITS_PER_ARRAY_ENTRY);
92 __le64 value = default_value ? cpu_to_le64(~0) : cpu_to_le64(0);
94 __dm_bless_for_disk(&value);
95 return dm_array_resize(&info->array_info, root, old_blocks, new_blocks,
98 EXPORT_SYMBOL_GPL(dm_bitset_resize);
100 int dm_bitset_del(struct dm_disk_bitset *info, dm_block_t root)
102 return dm_array_del(&info->array_info, root);
104 EXPORT_SYMBOL_GPL(dm_bitset_del);
106 int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root,
107 dm_block_t *new_root)
112 if (!info->current_index_set || !info->dirty)
115 value = cpu_to_le64(info->current_bits);
117 __dm_bless_for_disk(&value);
118 r = dm_array_set_value(&info->array_info, root, info->current_index,
123 info->current_index_set = false;
128 EXPORT_SYMBOL_GPL(dm_bitset_flush);
130 static int read_bits(struct dm_disk_bitset *info, dm_block_t root,
131 uint32_t array_index)
136 r = dm_array_get_value(&info->array_info, root, array_index, &value);
140 info->current_bits = le64_to_cpu(value);
141 info->current_index_set = true;
142 info->current_index = array_index;
148 static int get_array_entry(struct dm_disk_bitset *info, dm_block_t root,
149 uint32_t index, dm_block_t *new_root)
152 unsigned int array_index = index / BITS_PER_ARRAY_ENTRY;
154 if (info->current_index_set) {
155 if (info->current_index == array_index)
158 r = dm_bitset_flush(info, root, new_root);
163 return read_bits(info, root, array_index);
166 int dm_bitset_set_bit(struct dm_disk_bitset *info, dm_block_t root,
167 uint32_t index, dm_block_t *new_root)
170 unsigned int b = index % BITS_PER_ARRAY_ENTRY;
172 r = get_array_entry(info, root, index, new_root);
176 set_bit(b, (unsigned long *) &info->current_bits);
181 EXPORT_SYMBOL_GPL(dm_bitset_set_bit);
183 int dm_bitset_clear_bit(struct dm_disk_bitset *info, dm_block_t root,
184 uint32_t index, dm_block_t *new_root)
187 unsigned int b = index % BITS_PER_ARRAY_ENTRY;
189 r = get_array_entry(info, root, index, new_root);
193 clear_bit(b, (unsigned long *) &info->current_bits);
198 EXPORT_SYMBOL_GPL(dm_bitset_clear_bit);
200 int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root,
201 uint32_t index, dm_block_t *new_root, bool *result)
204 unsigned int b = index % BITS_PER_ARRAY_ENTRY;
206 r = get_array_entry(info, root, index, new_root);
210 *result = test_bit(b, (unsigned long *) &info->current_bits);
213 EXPORT_SYMBOL_GPL(dm_bitset_test_bit);
215 static int cursor_next_array_entry(struct dm_bitset_cursor *c)
220 r = dm_array_cursor_next(&c->cursor);
224 dm_array_cursor_get_value(&c->cursor, (void **) &value);
227 c->current_bits = le64_to_cpu(*value);
231 int dm_bitset_cursor_begin(struct dm_disk_bitset *info,
232 dm_block_t root, uint32_t nr_entries,
233 struct dm_bitset_cursor *c)
242 c->entries_remaining = nr_entries;
244 r = dm_array_cursor_begin(&info->array_info, root, &c->cursor);
248 dm_array_cursor_get_value(&c->cursor, (void **) &value);
251 c->current_bits = le64_to_cpu(*value);
255 EXPORT_SYMBOL_GPL(dm_bitset_cursor_begin);
257 void dm_bitset_cursor_end(struct dm_bitset_cursor *c)
259 return dm_array_cursor_end(&c->cursor);
261 EXPORT_SYMBOL_GPL(dm_bitset_cursor_end);
263 int dm_bitset_cursor_next(struct dm_bitset_cursor *c)
267 if (!c->entries_remaining)
270 c->entries_remaining--;
271 if (++c->bit_index > 63)
272 r = cursor_next_array_entry(c);
276 EXPORT_SYMBOL_GPL(dm_bitset_cursor_next);
278 int dm_bitset_cursor_skip(struct dm_bitset_cursor *c, uint32_t count)
282 uint32_t nr_array_skip;
283 uint32_t remaining_in_word = 64 - c->bit_index;
285 if (c->entries_remaining < count)
288 if (count < remaining_in_word) {
289 c->bit_index += count;
290 c->entries_remaining -= count;
294 c->entries_remaining -= remaining_in_word;
295 count -= remaining_in_word;
298 nr_array_skip = (count / 64) + 1;
299 r = dm_array_cursor_skip(&c->cursor, nr_array_skip);
303 dm_array_cursor_get_value(&c->cursor, (void **) &value);
304 c->entries_remaining -= count;
305 c->array_index += nr_array_skip;
306 c->bit_index = count & 63;
307 c->current_bits = le64_to_cpu(*value);
311 EXPORT_SYMBOL_GPL(dm_bitset_cursor_skip);
313 bool dm_bitset_cursor_get_value(struct dm_bitset_cursor *c)
315 return test_bit(c->bit_index, (unsigned long *) &c->current_bits);
317 EXPORT_SYMBOL_GPL(dm_bitset_cursor_get_value);
319 /*----------------------------------------------------------------*/