1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 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 64 16 17 /*----------------------------------------------------------------*/ 18 19 static 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 29 void 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 } 35 EXPORT_SYMBOL_GPL(dm_disk_bitset_init); 36 37 int dm_bitset_empty(struct dm_disk_bitset *info, dm_block_t *root) 38 { 39 return dm_array_empty(&info->array_info, root); 40 } 41 EXPORT_SYMBOL_GPL(dm_bitset_empty); 42 43 struct packer_context { 44 bit_value_fn fn; 45 unsigned int nr_bits; 46 void *context; 47 }; 48 49 static 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 else 65 clear_bit(bit, (unsigned long *) &word); 66 } 67 68 *((__le64 *) value) = cpu_to_le64(word); 69 70 return 0; 71 } 72 73 int 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 } 84 EXPORT_SYMBOL_GPL(dm_bitset_new); 85 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) 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 } 98 EXPORT_SYMBOL_GPL(dm_bitset_resize); 99 100 int dm_bitset_del(struct dm_disk_bitset *info, dm_block_t root) 101 { 102 return dm_array_del(&info->array_info, root); 103 } 104 EXPORT_SYMBOL_GPL(dm_bitset_del); 105 106 int 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 } 128 EXPORT_SYMBOL_GPL(dm_bitset_flush); 129 130 static 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 } 147 148 static 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 } 165 166 int 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 } 181 EXPORT_SYMBOL_GPL(dm_bitset_set_bit); 182 183 int 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 } 198 EXPORT_SYMBOL_GPL(dm_bitset_clear_bit); 199 200 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) 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 } 213 EXPORT_SYMBOL_GPL(dm_bitset_test_bit); 214 215 static 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 } 230 231 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) 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 } 255 EXPORT_SYMBOL_GPL(dm_bitset_cursor_begin); 256 257 void dm_bitset_cursor_end(struct dm_bitset_cursor *c) 258 { 259 return dm_array_cursor_end(&c->cursor); 260 } 261 EXPORT_SYMBOL_GPL(dm_bitset_cursor_end); 262 263 int 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 } 276 EXPORT_SYMBOL_GPL(dm_bitset_cursor_next); 277 278 int 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 } 311 EXPORT_SYMBOL_GPL(dm_bitset_cursor_skip); 312 313 bool dm_bitset_cursor_get_value(struct dm_bitset_cursor *c) 314 { 315 return test_bit(c->bit_index, (unsigned long *) &c->current_bits); 316 } 317 EXPORT_SYMBOL_GPL(dm_bitset_cursor_get_value); 318 319 /*----------------------------------------------------------------*/ 320