320 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2012 Red Hat, Inc.4 *5 * This file is released under the GPL.6 */7 8#include "dm-bitset.h"9#include "dm-transaction-manager.h"10 11#include <linux/export.h>12#include <linux/device-mapper.h>13 14#define DM_MSG_PREFIX "bitset"15#define BITS_PER_ARRAY_ENTRY 6416 17/*----------------------------------------------------------------*/18 19static struct dm_btree_value_type bitset_bvt = {20 .context = NULL,21 .size = sizeof(__le64),22 .inc = NULL,23 .dec = NULL,24 .equal = NULL,25};26 27/*----------------------------------------------------------------*/28 29void dm_disk_bitset_init(struct dm_transaction_manager *tm,30 struct dm_disk_bitset *info)31{32 dm_array_info_init(&info->array_info, tm, &bitset_bvt);33 info->current_index_set = false;34}35EXPORT_SYMBOL_GPL(dm_disk_bitset_init);36 37int dm_bitset_empty(struct dm_disk_bitset *info, dm_block_t *root)38{39 return dm_array_empty(&info->array_info, root);40}41EXPORT_SYMBOL_GPL(dm_bitset_empty);42 43struct packer_context {44 bit_value_fn fn;45 unsigned int nr_bits;46 void *context;47};48 49static int pack_bits(uint32_t index, void *value, void *context)50{51 int r;52 struct packer_context *p = context;53 unsigned int bit, nr = min(64u, p->nr_bits - (index * 64));54 uint64_t word = 0;55 bool bv;56 57 for (bit = 0; bit < nr; bit++) {58 r = p->fn(index * 64 + bit, &bv, p->context);59 if (r)60 return r;61 62 if (bv)63 set_bit(bit, (unsigned long *) &word);64 else65 clear_bit(bit, (unsigned long *) &word);66 }67 68 *((__le64 *) value) = cpu_to_le64(word);69 70 return 0;71}72 73int dm_bitset_new(struct dm_disk_bitset *info, dm_block_t *root,74 uint32_t size, bit_value_fn fn, void *context)75{76 struct packer_context p;77 78 p.fn = fn;79 p.nr_bits = size;80 p.context = context;81 82 return dm_array_new(&info->array_info, root, dm_div_up(size, 64), pack_bits, &p);83}84EXPORT_SYMBOL_GPL(dm_bitset_new);85 86int 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)89{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);93 94 __dm_bless_for_disk(&value);95 return dm_array_resize(&info->array_info, root, old_blocks, new_blocks,96 &value, new_root);97}98EXPORT_SYMBOL_GPL(dm_bitset_resize);99 100int dm_bitset_del(struct dm_disk_bitset *info, dm_block_t root)101{102 return dm_array_del(&info->array_info, root);103}104EXPORT_SYMBOL_GPL(dm_bitset_del);105 106int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root,107 dm_block_t *new_root)108{109 int r;110 __le64 value;111 112 if (!info->current_index_set || !info->dirty)113 return 0;114 115 value = cpu_to_le64(info->current_bits);116 117 __dm_bless_for_disk(&value);118 r = dm_array_set_value(&info->array_info, root, info->current_index,119 &value, new_root);120 if (r)121 return r;122 123 info->current_index_set = false;124 info->dirty = false;125 126 return 0;127}128EXPORT_SYMBOL_GPL(dm_bitset_flush);129 130static int read_bits(struct dm_disk_bitset *info, dm_block_t root,131 uint32_t array_index)132{133 int r;134 __le64 value;135 136 r = dm_array_get_value(&info->array_info, root, array_index, &value);137 if (r)138 return r;139 140 info->current_bits = le64_to_cpu(value);141 info->current_index_set = true;142 info->current_index = array_index;143 info->dirty = false;144 145 return 0;146}147 148static int get_array_entry(struct dm_disk_bitset *info, dm_block_t root,149 uint32_t index, dm_block_t *new_root)150{151 int r;152 unsigned int array_index = index / BITS_PER_ARRAY_ENTRY;153 154 if (info->current_index_set) {155 if (info->current_index == array_index)156 return 0;157 158 r = dm_bitset_flush(info, root, new_root);159 if (r)160 return r;161 }162 163 return read_bits(info, root, array_index);164}165 166int dm_bitset_set_bit(struct dm_disk_bitset *info, dm_block_t root,167 uint32_t index, dm_block_t *new_root)168{169 int r;170 unsigned int b = index % BITS_PER_ARRAY_ENTRY;171 172 r = get_array_entry(info, root, index, new_root);173 if (r)174 return r;175 176 set_bit(b, (unsigned long *) &info->current_bits);177 info->dirty = true;178 179 return 0;180}181EXPORT_SYMBOL_GPL(dm_bitset_set_bit);182 183int dm_bitset_clear_bit(struct dm_disk_bitset *info, dm_block_t root,184 uint32_t index, dm_block_t *new_root)185{186 int r;187 unsigned int b = index % BITS_PER_ARRAY_ENTRY;188 189 r = get_array_entry(info, root, index, new_root);190 if (r)191 return r;192 193 clear_bit(b, (unsigned long *) &info->current_bits);194 info->dirty = true;195 196 return 0;197}198EXPORT_SYMBOL_GPL(dm_bitset_clear_bit);199 200int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root,201 uint32_t index, dm_block_t *new_root, bool *result)202{203 int r;204 unsigned int b = index % BITS_PER_ARRAY_ENTRY;205 206 r = get_array_entry(info, root, index, new_root);207 if (r)208 return r;209 210 *result = test_bit(b, (unsigned long *) &info->current_bits);211 return 0;212}213EXPORT_SYMBOL_GPL(dm_bitset_test_bit);214 215static int cursor_next_array_entry(struct dm_bitset_cursor *c)216{217 int r;218 __le64 *value;219 220 r = dm_array_cursor_next(&c->cursor);221 if (r)222 return r;223 224 dm_array_cursor_get_value(&c->cursor, (void **) &value);225 c->array_index++;226 c->bit_index = 0;227 c->current_bits = le64_to_cpu(*value);228 return 0;229}230 231int dm_bitset_cursor_begin(struct dm_disk_bitset *info,232 dm_block_t root, uint32_t nr_entries,233 struct dm_bitset_cursor *c)234{235 int r;236 __le64 *value;237 238 if (!nr_entries)239 return -ENODATA;240 241 c->info = info;242 c->entries_remaining = nr_entries;243 244 r = dm_array_cursor_begin(&info->array_info, root, &c->cursor);245 if (r)246 return r;247 248 dm_array_cursor_get_value(&c->cursor, (void **) &value);249 c->array_index = 0;250 c->bit_index = 0;251 c->current_bits = le64_to_cpu(*value);252 253 return r;254}255EXPORT_SYMBOL_GPL(dm_bitset_cursor_begin);256 257void dm_bitset_cursor_end(struct dm_bitset_cursor *c)258{259 return dm_array_cursor_end(&c->cursor);260}261EXPORT_SYMBOL_GPL(dm_bitset_cursor_end);262 263int dm_bitset_cursor_next(struct dm_bitset_cursor *c)264{265 int r = 0;266 267 if (!c->entries_remaining)268 return -ENODATA;269 270 c->entries_remaining--;271 if (++c->bit_index > 63)272 r = cursor_next_array_entry(c);273 274 return r;275}276EXPORT_SYMBOL_GPL(dm_bitset_cursor_next);277 278int dm_bitset_cursor_skip(struct dm_bitset_cursor *c, uint32_t count)279{280 int r;281 __le64 *value;282 uint32_t nr_array_skip;283 uint32_t remaining_in_word = 64 - c->bit_index;284 285 if (c->entries_remaining < count)286 return -ENODATA;287 288 if (count < remaining_in_word) {289 c->bit_index += count;290 c->entries_remaining -= count;291 return 0;292 293 } else {294 c->entries_remaining -= remaining_in_word;295 count -= remaining_in_word;296 }297 298 nr_array_skip = (count / 64) + 1;299 r = dm_array_cursor_skip(&c->cursor, nr_array_skip);300 if (r)301 return r;302 303 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);308 309 return 0;310}311EXPORT_SYMBOL_GPL(dm_bitset_cursor_skip);312 313bool dm_bitset_cursor_get_value(struct dm_bitset_cursor *c)314{315 return test_bit(c->bit_index, (unsigned long *) &c->current_bits);316}317EXPORT_SYMBOL_GPL(dm_bitset_cursor_get_value);318 319/*----------------------------------------------------------------*/320