uspace/lib/ext4/libext4_balloc.c

   1 /*
   2  * Copyright (c) 2012 Frantisek Princ
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup libext4
  30  * @{
  31  */
  32 /**
  33  * @file  libext4_balloc.c
  34  * @brief Physical block allocator.
  35  */
  36
  37 #include <errno.h>
  38 #include <sys/types.h>
  39 #include "libext4.h"
  40
  41 /** Compute number of block group from block address.
  42  *
  43  * @param sb         Superblock pointer.
  44  * @param block_addr Absolute address of block.
  45  *
  46  * @return Block group index
  47  *
  48  */
  49 static uint32_t ext4_balloc_get_bgid_of_block(ext4_superblock_t *sb,
  50     uint32_t block_addr)
  51 {
  52         uint32_t blocks_per_group =
  53             ext4_superblock_get_blocks_per_group(sb);
  54         uint32_t first_block =
  55             ext4_superblock_get_first_data_block(sb);
  56
  57         /* First block == 0 or 1 */
  58         if (first_block == 0)
  59                 return block_addr / blocks_per_group;
  60         else
  61                 return (block_addr - 1) / blocks_per_group;
  62 }
  63
  64 /** Free block.
  65  *
  66  * @param inode_ref  Inode, where the block is allocated
  67  * @param block_addr Absolute block address to free
  68  *
  69  * @return Error code
  70  *
  71  */
  72 int ext4_balloc_free_block(ext4_inode_ref_t *inode_ref, uint32_t block_addr)
  73 {
  74         ext4_filesystem_t *fs = inode_ref->fs;
  75         ext4_superblock_t *sb = fs->superblock;
  76
  77         /* Compute indexes */
  78         uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, block_addr);
  79         uint32_t index_in_group =
  80             ext4_filesystem_blockaddr2_index_in_group(sb, block_addr);
  81
  82         /* Load block group reference */
  83         ext4_block_group_ref_t *bg_ref;
  84         int rc = ext4_filesystem_get_block_group_ref(fs, block_group, &bg_ref);
  85         if (rc != EOK)
  86                 return rc;
  87
  88         /* Load block with bitmap */
  89         uint32_t bitmap_block_addr =
  90             ext4_block_group_get_block_bitmap(bg_ref->block_group, sb);
  91         block_t *bitmap_block;
  92         rc = block_get(&bitmap_block, fs->device, bitmap_block_addr, 0);
  93         if (rc != EOK)
  94                 return rc;
  95
  96         /* Modify bitmap */
  97         ext4_bitmap_free_bit(bitmap_block->data, index_in_group);
  98         bitmap_block->dirty = true;
  99
 100         /* Release block with bitmap */
 101         rc = block_put(bitmap_block);
 102         if (rc != EOK) {
 103                 /* Error in saving bitmap */
 104                 ext4_filesystem_put_block_group_ref(bg_ref);
 105                 return rc;
 106         }
 107
 108         uint32_t block_size = ext4_superblock_get_block_size(sb);
 109
 110         /* Update superblock free blocks count */
 111         uint32_t sb_free_blocks =
 112             ext4_superblock_get_free_blocks_count(sb);
 113         sb_free_blocks++;
 114         ext4_superblock_set_free_blocks_count(sb, sb_free_blocks);
 115
 116         /* Update inode blocks count */
 117         uint64_t ino_blocks =
 118             ext4_inode_get_blocks_count(sb, inode_ref->inode);
 119         ino_blocks -= block_size / EXT4_INODE_BLOCK_SIZE;
 120         ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 121         inode_ref->dirty = true;
 122
 123         /* Update block group free blocks count */
 124         uint32_t free_blocks =
 125             ext4_block_group_get_free_blocks_count(bg_ref->block_group, sb);
 126         free_blocks++;
 127         ext4_block_group_set_free_blocks_count(bg_ref->block_group,
 128             sb, free_blocks);
 129         bg_ref->dirty = true;
 130
 131         /* Release block group reference */
 132         return ext4_filesystem_put_block_group_ref(bg_ref);
 133 }
 134
 135 /** Free continuous set of blocks.
 136  *
 137  * @param inode_ref Inode, where the blocks are allocated
 138  * @param first     First block to release
 139  * @param count     Number of blocks to release
 140  *
 141  */
 142 int ext4_balloc_free_blocks(ext4_inode_ref_t *inode_ref,
 143     uint32_t first, uint32_t count)
 144 {
 145         ext4_filesystem_t *fs = inode_ref->fs;
 146         ext4_superblock_t *sb = fs->superblock;
 147
 148         /* Compute indexes */
 149         uint32_t block_group_first =
 150             ext4_balloc_get_bgid_of_block(sb, first);
 151         uint32_t block_group_last =
 152             ext4_balloc_get_bgid_of_block(sb, first + count - 1);
 153
 154         assert(block_group_first == block_group_last);
 155
 156         /* Load block group reference */
 157         ext4_block_group_ref_t *bg_ref;
 158         int rc = ext4_filesystem_get_block_group_ref(fs, block_group_first, &bg_ref);
 159         if (rc != EOK)
 160                 return rc;
 161
 162         uint32_t index_in_group_first =
 163             ext4_filesystem_blockaddr2_index_in_group(sb, first);
 164
 165         /* Load block with bitmap */
 166         uint32_t bitmap_block_addr =
 167             ext4_block_group_get_block_bitmap(bg_ref->block_group, sb);
 168
 169         block_t *bitmap_block;
 170         rc = block_get(&bitmap_block, fs->device, bitmap_block_addr, 0);
 171         if (rc != EOK)
 172                 return rc;
 173
 174         /* Modify bitmap */
 175         ext4_bitmap_free_bits(bitmap_block->data, index_in_group_first, count);
 176         bitmap_block->dirty = true;
 177
 178         /* Release block with bitmap */
 179         rc = block_put(bitmap_block);
 180         if (rc != EOK) {
 181                 /* Error in saving bitmap */
 182                 ext4_filesystem_put_block_group_ref(bg_ref);
 183                 return rc;
 184         }
 185
 186         uint32_t block_size = ext4_superblock_get_block_size(sb);
 187
 188         /* Update superblock free blocks count */
 189         uint32_t sb_free_blocks =
 190             ext4_superblock_get_free_blocks_count(sb);
 191         sb_free_blocks += count;
 192         ext4_superblock_set_free_blocks_count(sb, sb_free_blocks);
 193
 194         /* Update inode blocks count */
 195         uint64_t ino_blocks =
 196             ext4_inode_get_blocks_count(sb, inode_ref->inode);
 197         ino_blocks -= count * (block_size / EXT4_INODE_BLOCK_SIZE);
 198         ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 199         inode_ref->dirty = true;
 200
 201         /* Update block group free blocks count */
 202         uint32_t free_blocks =
 203             ext4_block_group_get_free_blocks_count(bg_ref->block_group, sb);
 204         free_blocks += count;
 205         ext4_block_group_set_free_blocks_count(bg_ref->block_group,
 206             sb, free_blocks);
 207         bg_ref->dirty = true;
 208
 209         /* Release block group reference */
 210         return ext4_filesystem_put_block_group_ref(bg_ref);
 211 }
 212
 213 /** Compute first block for data in block group.
 214  *
 215  * @param sb   Pointer to superblock
 216  * @param bg   Pointer to block group
 217  * @param bgid Index of block group
 218  *
 219  * @return Absolute block index of first block
 220  *
 221  */
 222 uint32_t ext4_balloc_get_first_data_block_in_group(ext4_superblock_t *sb,
 223     ext4_block_group_ref_t *bg_ref)
 224 {
 225         uint32_t block_group_count = ext4_superblock_get_block_group_count(sb);
 226         uint32_t inode_table_first_block =
 227             ext4_block_group_get_inode_table_first_block(bg_ref->block_group, sb);
 228         uint16_t inode_table_item_size = ext4_superblock_get_inode_size(sb);
 229         uint32_t inodes_per_group = ext4_superblock_get_inodes_per_group(sb);
 230         uint32_t block_size = ext4_superblock_get_block_size(sb);
 231         uint32_t inode_table_bytes;
 232
 233         if (bg_ref->index < block_group_count - 1) {
 234                 inode_table_bytes = inodes_per_group * inode_table_item_size;
 235         } else {
 236                 /* Last block group could be smaller */
 237                 uint32_t inodes_count_total = ext4_superblock_get_inodes_count(sb);
 238                 inode_table_bytes =
 239                     (inodes_count_total - ((block_group_count - 1) * inodes_per_group)) *
 240                     inode_table_item_size;
 241         }
 242
 243         uint32_t inode_table_blocks = inode_table_bytes / block_size;
 244
 245         if (inode_table_bytes % block_size)
 246                 inode_table_blocks++;
 247
 248         return inode_table_first_block + inode_table_blocks;
 249 }
 250
 251 /** Compute 'goal' for allocation algorithm.
 252  *
 253  * @param inode_ref Reference to inode, to allocate block for
 254  *
 255  * @return Goal block number
 256  *
 257  */
 258 static int ext4_balloc_find_goal(ext4_inode_ref_t *inode_ref, uint32_t *goal)
 259 {
 260         *goal = 0;
 261         ext4_superblock_t *sb = inode_ref->fs->superblock;
 262
 263         uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
 264         uint32_t block_size = ext4_superblock_get_block_size(sb);
 265         uint32_t inode_block_count = inode_size / block_size;
 266
 267         if (inode_size % block_size != 0)
 268                 inode_block_count++;
 269
 270         /* If inode has some blocks, get last block address + 1 */
 271         if (inode_block_count > 0) {
 272                 int rc = ext4_filesystem_get_inode_data_block_index(inode_ref,
 273                     inode_block_count - 1, goal);
 274                 if (rc != EOK)
 275                         return rc;
 276
 277                 if (goal != 0) {
 278                         (*goal)++;
 279                         return EOK;
 280                 }
 281
 282                 /* If goal == 0, sparse file -> continue */
 283         }
 284
 285         /* Identify block group of inode */
 286         uint32_t inodes_per_group = ext4_superblock_get_inodes_per_group(sb);
 287         uint32_t block_group = (inode_ref->index - 1) / inodes_per_group;
 288         block_size = ext4_superblock_get_block_size(sb);
 289
 290         /* Load block group reference */
 291         ext4_block_group_ref_t *bg_ref;
 292         int rc = ext4_filesystem_get_block_group_ref(inode_ref->fs,
 293             block_group, &bg_ref);
 294         if (rc != EOK)
 295                 return rc;
 296
 297         /* Compute indexes */
 298         uint32_t block_group_count = ext4_superblock_get_block_group_count(sb);
 299         uint32_t inode_table_first_block =
 300             ext4_block_group_get_inode_table_first_block(bg_ref->block_group, sb);
 301         uint16_t inode_table_item_size = ext4_superblock_get_inode_size(sb);
 302         uint32_t inode_table_bytes;
 303
 304         /* Check for last block group */
 305         if (block_group < block_group_count - 1) {
 306                 inode_table_bytes = inodes_per_group * inode_table_item_size;
 307         } else {
 308                 /* Last block group could be smaller */
 309                 uint32_t inodes_count_total = ext4_superblock_get_inodes_count(sb);
 310                 inode_table_bytes =
 311                     (inodes_count_total - ((block_group_count - 1) * inodes_per_group)) *
 312                     inode_table_item_size;
 313         }
 314
 315         uint32_t inode_table_blocks = inode_table_bytes / block_size;
 316
 317         if (inode_table_bytes % block_size)
 318                 inode_table_blocks++;
 319
 320         *goal = inode_table_first_block + inode_table_blocks;
 321
 322         return ext4_filesystem_put_block_group_ref(bg_ref);
 323 }
 324
 325 /** Data block allocation algorithm.
 326  *
 327  * @param inode_ref Inode to allocate block for
 328  * @param fblock    Allocated block address
 329  *
 330  * @return Error code
 331  *
 332  */
 333 int ext4_balloc_alloc_block(ext4_inode_ref_t *inode_ref, uint32_t *fblock)
 334 {
 335         uint32_t allocated_block = 0;
 336
 337         uint32_t bitmap_block_addr;
 338         block_t *bitmap_block;
 339         uint32_t rel_block_idx = 0;
 340         uint32_t goal;
 341
 342         /* Find GOAL */
 343         int rc = ext4_balloc_find_goal(inode_ref, &goal);
 344         if (rc != EOK)
 345                 return rc;
 346         else if (goal == 0) {
 347                 /* no goal found => partition is full */
 348                 return ENOMEM;
 349         }
 350
 351         ext4_superblock_t *sb = inode_ref->fs->superblock;
 352
 353         /* Load block group number for goal and relative index */
 354         uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, goal);
 355         uint32_t index_in_group =
 356             ext4_filesystem_blockaddr2_index_in_group(sb, goal);
 357
 358         /* Load block group reference */
 359         ext4_block_group_ref_t *bg_ref;
 360         rc = ext4_filesystem_get_block_group_ref(inode_ref->fs,
 361             block_group, &bg_ref);
 362         if (rc != EOK)
 363                 return rc;
 364
 365         /* Compute indexes */
 366         uint32_t first_in_group =
 367             ext4_balloc_get_first_data_block_in_group(sb, bg_ref);
 368
 369         uint32_t first_in_group_index =
 370             ext4_filesystem_blockaddr2_index_in_group(sb, first_in_group);
 371
 372         if (index_in_group < first_in_group_index)
 373                 index_in_group = first_in_group_index;
 374
 375         /* Load block with bitmap */
 376         bitmap_block_addr =
 377             ext4_block_group_get_block_bitmap(bg_ref->block_group, sb);
 378
 379         rc = block_get(&bitmap_block, inode_ref->fs->device,
 380             bitmap_block_addr, BLOCK_FLAGS_NONE);
 381         if (rc != EOK) {
 382                 ext4_filesystem_put_block_group_ref(bg_ref);
 383                 return rc;
 384         }
 385
 386         /* Check if goal is free */
 387         if (ext4_bitmap_is_free_bit(bitmap_block->data, index_in_group)) {
 388                 ext4_bitmap_set_bit(bitmap_block->data, index_in_group);
 389                 bitmap_block->dirty = true;
 390                 rc = block_put(bitmap_block);
 391                 if (rc != EOK) {
 392                         ext4_filesystem_put_block_group_ref(bg_ref);
 393                         return rc;
 394                 }
 395
 396                 allocated_block =
 397                     ext4_filesystem_index_in_group2blockaddr(sb, index_in_group,
 398                     block_group);
 399
 400                 goto success;
 401         }
 402
 403         uint32_t blocks_in_group =
 404             ext4_superblock_get_blocks_in_group(sb, block_group);
 405
 406         uint32_t end_idx = (index_in_group + 63) & ~63;
 407         if (end_idx > blocks_in_group)
 408                 end_idx = blocks_in_group;
 409
 410         /* Try to find free block near to goal */
 411         for (uint32_t tmp_idx = index_in_group + 1; tmp_idx < end_idx;
 412             ++tmp_idx) {
 413                 if (ext4_bitmap_is_free_bit(bitmap_block->data, tmp_idx)) {
 414                         ext4_bitmap_set_bit(bitmap_block->data, tmp_idx);
 415                         bitmap_block->dirty = true;
 416                         rc = block_put(bitmap_block);
 417                         if (rc != EOK)
 418                                 return rc;
 419
 420                         allocated_block =
 421                             ext4_filesystem_index_in_group2blockaddr(sb, tmp_idx,
 422                             block_group);
 423
 424                         goto success;
 425                 }
 426         }
 427
 428         /* Find free BYTE in bitmap */
 429         rc = ext4_bitmap_find_free_byte_and_set_bit(bitmap_block->data,
 430             index_in_group, &rel_block_idx, blocks_in_group);
 431         if (rc == EOK) {
 432                 bitmap_block->dirty = true;
 433                 rc = block_put(bitmap_block);
 434                 if (rc != EOK)
 435                         return rc;
 436
 437                 allocated_block =
 438                     ext4_filesystem_index_in_group2blockaddr(sb, rel_block_idx,
 439                     block_group);
 440
 441                 goto success;
 442         }
 443
 444         /* Find free bit in bitmap */
 445         rc = ext4_bitmap_find_free_bit_and_set(bitmap_block->data,
 446             index_in_group, &rel_block_idx, blocks_in_group);
 447         if (rc == EOK) {
 448                 bitmap_block->dirty = true;
 449                 rc = block_put(bitmap_block);
 450                 if (rc != EOK)
 451                         return rc;
 452
 453                 allocated_block =
 454                     ext4_filesystem_index_in_group2blockaddr(sb, rel_block_idx,
 455                     block_group);
 456
 457                 goto success;
 458         }
 459
 460         /* No free block found yet */
 461         rc = block_put(bitmap_block);
 462         if (rc != EOK) {
 463                 ext4_filesystem_put_block_group_ref(bg_ref);
 464                 return rc;
 465         }
 466
 467         rc = ext4_filesystem_put_block_group_ref(bg_ref);
 468         if (rc != EOK)
 469                 return rc;
 470
 471         /* Try other block groups */
 472         uint32_t block_group_count = ext4_superblock_get_block_group_count(sb);
 473
 474         uint32_t bgid = (block_group + 1) % block_group_count;
 475         uint32_t count = block_group_count;
 476
 477         while (count > 0) {
 478                 rc = ext4_filesystem_get_block_group_ref(inode_ref->fs, bgid,
 479                     &bg_ref);
 480                 if (rc != EOK)
 481                         return rc;
 482
 483                 /* Load block with bitmap */
 484                 bitmap_block_addr =
 485                     ext4_block_group_get_block_bitmap(bg_ref->block_group, sb);
 486
 487                 rc = block_get(&bitmap_block, inode_ref->fs->device,
 488                     bitmap_block_addr, 0);
 489                 if (rc != EOK) {
 490                         ext4_filesystem_put_block_group_ref(bg_ref);
 491                         return rc;
 492                 }
 493
 494                 /* Compute indexes */
 495                 first_in_group =
 496                     ext4_balloc_get_first_data_block_in_group(sb, bg_ref);
 497                 index_in_group =
 498                     ext4_filesystem_blockaddr2_index_in_group(sb, first_in_group);
 499                 blocks_in_group = ext4_superblock_get_blocks_in_group(sb, bgid);
 500
 501                 first_in_group_index =
 502                     ext4_filesystem_blockaddr2_index_in_group(sb, first_in_group);
 503
 504                 if (index_in_group < first_in_group_index)
 505                         index_in_group = first_in_group_index;
 506
 507                 /* Try to find free byte in bitmap */
 508                 rc = ext4_bitmap_find_free_byte_and_set_bit(bitmap_block->data,
 509                     index_in_group, &rel_block_idx, blocks_in_group);
 510                 if (rc == EOK) {
 511                         bitmap_block->dirty = true;
 512                         rc = block_put(bitmap_block);
 513                         if (rc != EOK)
 514                                 return rc;
 515
 516                         allocated_block =
 517                             ext4_filesystem_index_in_group2blockaddr(sb, rel_block_idx,
 518                             bgid);
 519
 520                         goto success;
 521                 }
 522
 523                 /* Try to find free bit in bitmap */
 524                 rc = ext4_bitmap_find_free_bit_and_set(bitmap_block->data,
 525                     index_in_group, &rel_block_idx, blocks_in_group);
 526                 if (rc == EOK) {
 527                         bitmap_block->dirty = true;
 528                         rc = block_put(bitmap_block);
 529                         if (rc != EOK)
 530                                 return rc;
 531
 532                         allocated_block =
 533                             ext4_filesystem_index_in_group2blockaddr(sb, rel_block_idx,
 534                             bgid);
 535
 536                         goto success;
 537                 }
 538
 539                 rc = block_put(bitmap_block);
 540                 if (rc != EOK) {
 541                         ext4_filesystem_put_block_group_ref(bg_ref);
 542                         return rc;
 543                 }
 544
 545                 rc = ext4_filesystem_put_block_group_ref(bg_ref);
 546                 if (rc != EOK)
 547                         return rc;
 548
 549                 /* Goto next group */
 550                 bgid = (bgid + 1) % block_group_count;
 551                 count--;
 552         }
 553
 554         return ENOSPC;
 555
 556 success:
 557         /* Empty command - because of syntax */
 558         ;
 559
 560         uint32_t block_size = ext4_superblock_get_block_size(sb);
 561
 562         /* Update superblock free blocks count */
 563         uint32_t sb_free_blocks = ext4_superblock_get_free_blocks_count(sb);
 564         sb_free_blocks--;
 565         ext4_superblock_set_free_blocks_count(sb, sb_free_blocks);
 566
 567         /* Update inode blocks (different block size!) count */
 568         uint64_t ino_blocks =
 569             ext4_inode_get_blocks_count(sb, inode_ref->inode);
 570         ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
 571         ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 572         inode_ref->dirty = true;
 573
 574         /* Update block group free blocks count */
 575         uint32_t bg_free_blocks =
 576             ext4_block_group_get_free_blocks_count(bg_ref->block_group, sb);
 577         bg_free_blocks--;
 578         ext4_block_group_set_free_blocks_count(bg_ref->block_group, sb,
 579             bg_free_blocks);
 580         bg_ref->dirty = true;
 581
 582         rc = ext4_filesystem_put_block_group_ref(bg_ref);
 583
 584         *fblock = allocated_block;
 585         return rc;
 586 }
 587
 588 /** Try to allocate concrete block.
 589  *
 590  * @param inode_ref Inode to allocate block for
 591  * @param fblock    Block address to allocate
 592  * @param free      Output value - if target block is free
 593  *
 594  * @return Error code
 595  *
 596  */
 597 int ext4_balloc_try_alloc_block(ext4_inode_ref_t *inode_ref, uint32_t fblock,
 598     bool *free)
 599 {
 600         int rc = EOK;
 601
 602         ext4_filesystem_t *fs = inode_ref->fs;
 603         ext4_superblock_t *sb = fs->superblock;
 604
 605         /* Compute indexes */
 606         uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, fblock);
 607         uint32_t index_in_group =
 608             ext4_filesystem_blockaddr2_index_in_group(sb, fblock);
 609
 610         /* Load block group reference */
 611         ext4_block_group_ref_t *bg_ref;
 612         rc = ext4_filesystem_get_block_group_ref(fs, block_group, &bg_ref);
 613         if (rc != EOK)
 614                 return rc;
 615
 616         /* Load block with bitmap */
 617         uint32_t bitmap_block_addr =
 618             ext4_block_group_get_block_bitmap(bg_ref->block_group, sb);
 619         block_t *bitmap_block;
 620         rc = block_get(&bitmap_block, fs->device, bitmap_block_addr, 0);
 621         if (rc != EOK)
 622                 return rc;
 623
 624         /* Check if block is free */
 625         *free = ext4_bitmap_is_free_bit(bitmap_block->data, index_in_group);
 626
 627         /* Allocate block if possible */
 628         if (*free) {
 629                 ext4_bitmap_set_bit(bitmap_block->data, index_in_group);
 630                 bitmap_block->dirty = true;
 631         }
 632
 633         /* Release block with bitmap */
 634         rc = block_put(bitmap_block);
 635         if (rc != EOK) {
 636                 /* Error in saving bitmap */
 637                 ext4_filesystem_put_block_group_ref(bg_ref);
 638                 return rc;
 639         }
 640
 641         /* If block is not free, return */
 642         if (!(*free))
 643                 goto terminate;
 644
 645         uint32_t block_size = ext4_superblock_get_block_size(sb);
 646
 647         /* Update superblock free blocks count */
 648         uint32_t sb_free_blocks = ext4_superblock_get_free_blocks_count(sb);
 649         sb_free_blocks--;
 650         ext4_superblock_set_free_blocks_count(sb, sb_free_blocks);
 651
 652         /* Update inode blocks count */
 653         uint64_t ino_blocks =
 654             ext4_inode_get_blocks_count(sb, inode_ref->inode);
 655         ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
 656         ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 657         inode_ref->dirty = true;
 658
 659         /* Update block group free blocks count */
 660         uint32_t free_blocks =
 661             ext4_block_group_get_free_blocks_count(bg_ref->block_group, sb);
 662         free_blocks--;
 663         ext4_block_group_set_free_blocks_count(bg_ref->block_group,
 664             sb, free_blocks);
 665         bg_ref->dirty = true;
 666
 667 terminate:
 668         return ext4_filesystem_put_block_group_ref(bg_ref);
 669 }
 670
 671 /**
 672  * @}
 673  */