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         rc = ext4_filesystem_put_block_group_ref(bg_ref);
 133         if (rc != EOK)
 134                 return rc;
 135
 136         return EOK;
 137 }
 138
 139 /** Free continuous set of blocks.
 140  *
 141  * @param inode_ref Inode, where the blocks are allocated
 142  * @param first     First block to release
 143  * @param count     Number of blocks to release
 144  *
 145  */
 146 int ext4_balloc_free_blocks(ext4_inode_ref_t *inode_ref,
 147     uint32_t first, uint32_t count)
 148 {
 149         ext4_filesystem_t *fs = inode_ref->fs;
 150         ext4_superblock_t *sb = fs->superblock;
 151
 152         /* Compute indexes */
 153         uint32_t block_group_first =
 154             ext4_balloc_get_bgid_of_block(sb, first);
 155         uint32_t block_group_last =
 156             ext4_balloc_get_bgid_of_block(sb, first + count - 1);
 157
 158         assert(block_group_first == block_group_last);
 159
 160         /* Load block group reference */
 161         ext4_block_group_ref_t *bg_ref;
 162         int rc = ext4_filesystem_get_block_group_ref(fs, block_group_first, &bg_ref);
 163         if (rc != EOK)
 164                 return rc;
 165
 166         uint32_t index_in_group_first =
 167             ext4_filesystem_blockaddr2_index_in_group(sb, first);
 168
 169         /* Load block with bitmap */
 170         uint32_t bitmap_block_addr =
 171             ext4_block_group_get_block_bitmap(bg_ref->block_group, sb);
 172
 173         block_t *bitmap_block;
 174         rc = block_get(&bitmap_block, fs->device, bitmap_block_addr, 0);
 175         if (rc != EOK)
 176                 return rc;
 177
 178         /* Modify bitmap */
 179         ext4_bitmap_free_bits(bitmap_block->data, index_in_group_first, count);
 180         bitmap_block->dirty = true;
 181
 182         /* Release block with bitmap */
 183         rc = block_put(bitmap_block);
 184         if (rc != EOK) {
 185                 /* Error in saving bitmap */
 186                 ext4_filesystem_put_block_group_ref(bg_ref);
 187                 return rc;
 188         }
 189
 190         uint32_t block_size = ext4_superblock_get_block_size(sb);
 191
 192         /* Update superblock free blocks count */
 193         uint32_t sb_free_blocks =
 194             ext4_superblock_get_free_blocks_count(sb);
 195         sb_free_blocks += count;
 196         ext4_superblock_set_free_blocks_count(sb, sb_free_blocks);
 197
 198         /* Update inode blocks count */
 199         uint64_t ino_blocks =
 200             ext4_inode_get_blocks_count(sb, inode_ref->inode);
 201         ino_blocks -= count * (block_size / EXT4_INODE_BLOCK_SIZE);
 202         ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 203         inode_ref->dirty = true;
 204
 205         /* Update block group free blocks count */
 206         uint32_t free_blocks =
 207             ext4_block_group_get_free_blocks_count(bg_ref->block_group, sb);
 208         free_blocks += count;
 209         ext4_block_group_set_free_blocks_count(bg_ref->block_group,
 210             sb, free_blocks);
 211         bg_ref->dirty = true;
 212
 213         /* Release block group reference */
 214         rc = ext4_filesystem_put_block_group_ref(bg_ref);
 215         if (rc != EOK)
 216                 return rc;
 217
 218         return EOK;
 219 }
 220
 221 /** Compute first block for data in block group.
 222  *
 223  * @param sb   Pointer to superblock
 224  * @param bg   Pointer to block group
 225  * @param bgid Index of block group
 226  *
 227  * @return Absolute block index of first block
 228  *
 229  */
 230 uint32_t ext4_balloc_get_first_data_block_in_group(ext4_superblock_t *sb,
 231     ext4_block_group_ref_t *bg_ref)
 232 {
 233         uint32_t block_group_count = ext4_superblock_get_block_group_count(sb);
 234         uint32_t inode_table_first_block =
 235             ext4_block_group_get_inode_table_first_block(bg_ref->block_group, sb);
 236         uint16_t inode_table_item_size = ext4_superblock_get_inode_size(sb);
 237         uint32_t inodes_per_group = ext4_superblock_get_inodes_per_group(sb);
 238         uint32_t block_size = ext4_superblock_get_block_size(sb);
 239         uint32_t inode_table_bytes;
 240
 241         if (bg_ref->index < block_group_count - 1) {
 242                 inode_table_bytes = inodes_per_group * inode_table_item_size;
 243         } else {
 244                 /* Last block group could be smaller */
 245                 uint32_t inodes_count_total = ext4_superblock_get_inodes_count(sb);
 246                 inode_table_bytes =
 247                     (inodes_count_total - ((block_group_count - 1) * inodes_per_group)) *
 248                     inode_table_item_size;
 249         }
 250
 251         uint32_t inode_table_blocks = inode_table_bytes / block_size;
 252
 253         if (inode_table_bytes % block_size)
 254                 inode_table_blocks++;
 255
 256         return inode_table_first_block + inode_table_blocks;
 257 }
 258
 259 /** Compute 'goal' for allocation algorithm.
 260  *
 261  * @param inode_ref Reference to inode, to allocate block for
 262  *
 263  * @return Goal block number
 264  *
 265  */
 266 static int ext4_balloc_find_goal(ext4_inode_ref_t *inode_ref, uint32_t *goal)
 267 {
 268         *goal = 0;
 269         ext4_superblock_t *sb = inode_ref->fs->superblock;
 270
 271         uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
 272         uint32_t block_size = ext4_superblock_get_block_size(sb);
 273         uint32_t inode_block_count = inode_size / block_size;
 274
 275         if (inode_size % block_size != 0)
 276                 inode_block_count++;
 277
 278         /* If inode has some blocks, get last block address + 1 */
 279         if (inode_block_count > 0) {
 280                 int rc = ext4_filesystem_get_inode_data_block_index(inode_ref,
 281                     inode_block_count - 1, goal);
 282                 if (rc != EOK)
 283                         return rc;
 284
 285                 if (goal != 0) {
 286                         (*goal)++;
 287                         return EOK;
 288                 }
 289
 290                 /* If goal == 0, sparse file -> continue */
 291         }
 292
 293         /* Identify block group of inode */
 294         uint32_t inodes_per_group = ext4_superblock_get_inodes_per_group(sb);
 295         uint32_t block_group = (inode_ref->index - 1) / inodes_per_group;
 296         block_size = ext4_superblock_get_block_size(sb);
 297
 298         /* Load block group reference */
 299         ext4_block_group_ref_t *bg_ref;
 300         int rc = ext4_filesystem_get_block_group_ref(inode_ref->fs,
 301             block_group, &bg_ref);
 302         if (rc != EOK)
 303                 return rc;
 304
 305         /* Compute indexes */
 306         uint32_t block_group_count = ext4_superblock_get_block_group_count(sb);
 307         uint32_t inode_table_first_block =
 308             ext4_block_group_get_inode_table_first_block(bg_ref->block_group, sb);
 309         uint16_t inode_table_item_size = ext4_superblock_get_inode_size(sb);
 310         uint32_t inode_table_bytes;
 311
 312         /* Check for last block group */
 313         if (block_group < block_group_count - 1) {
 314                 inode_table_bytes = inodes_per_group * inode_table_item_size;
 315         } else {
 316                 /* Last block group could be smaller */
 317                 uint32_t inodes_count_total = ext4_superblock_get_inodes_count(sb);
 318                 inode_table_bytes =
 319                     (inodes_count_total - ((block_group_count - 1) * inodes_per_group)) *
 320                     inode_table_item_size;
 321         }
 322
 323         uint32_t inode_table_blocks = inode_table_bytes / block_size;
 324
 325         if (inode_table_bytes % block_size)
 326                 inode_table_blocks++;
 327
 328         *goal = inode_table_first_block + inode_table_blocks;
 329
 330         ext4_filesystem_put_block_group_ref(bg_ref);
 331
 332         return EOK;
 333 }
 334
 335 /** Data block allocation algorithm.
 336  *
 337  * @param inode_ref Inode to allocate block for
 338  * @param fblock    Allocated block address
 339  *
 340  * @return Error code
 341  *
 342  */
 343 int ext4_balloc_alloc_block(ext4_inode_ref_t *inode_ref, uint32_t *fblock)
 344 {
 345         uint32_t allocated_block = 0;
 346
 347         uint32_t bitmap_block_addr;
 348         block_t *bitmap_block;
 349         uint32_t rel_block_idx = 0;
 350         uint32_t goal;
 351
 352         /* Find GOAL */
 353         int rc = ext4_balloc_find_goal(inode_ref, &goal);
 354         if (rc != EOK)
 355                 return rc;
 356         else if (goal == 0) {
 357                 /* no goal found => partition is full */
 358                 return ENOMEM;
 359         }
 360
 361         ext4_superblock_t *sb = inode_ref->fs->superblock;
 362
 363         /* Load block group number for goal and relative index */
 364         uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, goal);
 365         uint32_t index_in_group =
 366             ext4_filesystem_blockaddr2_index_in_group(sb, goal);
 367
 368         /* Load block group reference */
 369         ext4_block_group_ref_t *bg_ref;
 370         rc = ext4_filesystem_get_block_group_ref(inode_ref->fs,
 371             block_group, &bg_ref);
 372         if (rc != EOK)
 373                 return rc;
 374
 375         /* Compute indexes */
 376         uint32_t first_in_group =
 377             ext4_balloc_get_first_data_block_in_group(sb, bg_ref);
 378
 379         uint32_t first_in_group_index =
 380             ext4_filesystem_blockaddr2_index_in_group(sb, first_in_group);
 381
 382         if (index_in_group < first_in_group_index)
 383                 index_in_group = first_in_group_index;
 384
 385         /* Load block with bitmap */
 386         bitmap_block_addr =
 387             ext4_block_group_get_block_bitmap(bg_ref->block_group, sb);
 388
 389         rc = block_get(&bitmap_block, inode_ref->fs->device,
 390             bitmap_block_addr, BLOCK_FLAGS_NONE);
 391         if (rc != EOK) {
 392                 ext4_filesystem_put_block_group_ref(bg_ref);
 393                 return rc;
 394         }
 395
 396         /* Check if goal is free */
 397         if (ext4_bitmap_is_free_bit(bitmap_block->data, index_in_group)) {
 398                 ext4_bitmap_set_bit(bitmap_block->data, index_in_group);
 399                 bitmap_block->dirty = true;
 400                 rc = block_put(bitmap_block);
 401                 if (rc != EOK) {
 402                         ext4_filesystem_put_block_group_ref(bg_ref);
 403                         return rc;
 404                 }
 405
 406                 allocated_block =
 407                     ext4_filesystem_index_in_group2blockaddr(sb, index_in_group,
 408                     block_group);
 409
 410                 goto success;
 411         }
 412
 413         uint32_t blocks_in_group =
 414             ext4_superblock_get_blocks_in_group(sb, block_group);
 415
 416         uint32_t end_idx = (index_in_group + 63) & ~63;
 417         if (end_idx > blocks_in_group)
 418                 end_idx = blocks_in_group;
 419
 420         /* Try to find free block near to goal */
 421         for (uint32_t tmp_idx = index_in_group + 1; tmp_idx < end_idx;
 422             ++tmp_idx) {
 423                 if (ext4_bitmap_is_free_bit(bitmap_block->data, tmp_idx)) {
 424                         ext4_bitmap_set_bit(bitmap_block->data, tmp_idx);
 425                         bitmap_block->dirty = true;
 426                         rc = block_put(bitmap_block);
 427                         if (rc != EOK)
 428                                 return rc;
 429
 430                         allocated_block =
 431                             ext4_filesystem_index_in_group2blockaddr(sb, tmp_idx,
 432                             block_group);
 433
 434                         goto success;
 435                 }
 436         }
 437
 438         /* Find free BYTE in bitmap */
 439         rc = ext4_bitmap_find_free_byte_and_set_bit(bitmap_block->data,
 440             index_in_group, &rel_block_idx, blocks_in_group);
 441         if (rc == EOK) {
 442                 bitmap_block->dirty = true;
 443                 rc = block_put(bitmap_block);
 444                 if (rc != EOK)
 445                         return rc;
 446
 447                 allocated_block =
 448                     ext4_filesystem_index_in_group2blockaddr(sb, rel_block_idx,
 449                     block_group);
 450
 451                 goto success;
 452         }
 453
 454         /* Find free bit in bitmap */
 455         rc = ext4_bitmap_find_free_bit_and_set(bitmap_block->data,
 456             index_in_group, &rel_block_idx, blocks_in_group);
 457         if (rc == EOK) {
 458                 bitmap_block->dirty = true;
 459                 rc = block_put(bitmap_block);
 460                 if (rc != EOK)
 461                         return rc;
 462
 463                 allocated_block =
 464                     ext4_filesystem_index_in_group2blockaddr(sb, rel_block_idx,
 465                     block_group);
 466
 467                 goto success;
 468         }
 469
 470         /* No free block found yet */
 471         block_put(bitmap_block);
 472         ext4_filesystem_put_block_group_ref(bg_ref);
 473
 474         /* Try other block groups */
 475         uint32_t block_group_count = ext4_superblock_get_block_group_count(sb);
 476
 477         uint32_t bgid = (block_group + 1) % block_group_count;
 478         uint32_t count = block_group_count;
 479
 480         while (count > 0) {
 481                 rc = ext4_filesystem_get_block_group_ref(inode_ref->fs, bgid,
 482                     &bg_ref);
 483                 if (rc != EOK)
 484                         return rc;
 485
 486                 /* Load block with bitmap */
 487                 bitmap_block_addr =
 488                     ext4_block_group_get_block_bitmap(bg_ref->block_group, sb);
 489
 490                 rc = block_get(&bitmap_block, inode_ref->fs->device,
 491                     bitmap_block_addr, 0);
 492                 if (rc != EOK) {
 493                         ext4_filesystem_put_block_group_ref(bg_ref);
 494                         return rc;
 495                 }
 496
 497                 /* Compute indexes */
 498                 first_in_group =
 499                     ext4_balloc_get_first_data_block_in_group(sb, bg_ref);
 500                 index_in_group =
 501                     ext4_filesystem_blockaddr2_index_in_group(sb, first_in_group);
 502                 blocks_in_group = ext4_superblock_get_blocks_in_group(sb, bgid);
 503
 504                 first_in_group_index =
 505                     ext4_filesystem_blockaddr2_index_in_group(sb, first_in_group);
 506
 507                 if (index_in_group < first_in_group_index)
 508                         index_in_group = first_in_group_index;
 509
 510                 /* Try to find free byte in bitmap */
 511                 rc = ext4_bitmap_find_free_byte_and_set_bit(bitmap_block->data,
 512                     index_in_group, &rel_block_idx, blocks_in_group);
 513                 if (rc == EOK) {
 514                         bitmap_block->dirty = true;
 515                         rc = block_put(bitmap_block);
 516                         if (rc != EOK)
 517                                 return rc;
 518
 519                         allocated_block =
 520                             ext4_filesystem_index_in_group2blockaddr(sb, rel_block_idx,
 521                             bgid);
 522
 523                         goto success;
 524                 }
 525
 526                 /* Try to find free bit in bitmap */
 527                 rc = ext4_bitmap_find_free_bit_and_set(bitmap_block->data,
 528                     index_in_group, &rel_block_idx, blocks_in_group);
 529                 if (rc == EOK) {
 530                         bitmap_block->dirty = true;
 531                         rc = block_put(bitmap_block);
 532                         if (rc != EOK)
 533                                 return rc;
 534
 535                         allocated_block =
 536                             ext4_filesystem_index_in_group2blockaddr(sb, rel_block_idx,
 537                             bgid);
 538
 539                         goto success;
 540                 }
 541
 542                 block_put(bitmap_block);
 543                 ext4_filesystem_put_block_group_ref(bg_ref);
 544
 545                 /* Goto next group */
 546                 bgid = (bgid + 1) % block_group_count;
 547                 count--;
 548         }
 549
 550         return ENOSPC;
 551
 552 success:
 553         /* Empty command - because of syntax */
 554         ;
 555
 556         uint32_t block_size = ext4_superblock_get_block_size(sb);
 557
 558         /* Update superblock free blocks count */
 559         uint32_t sb_free_blocks = ext4_superblock_get_free_blocks_count(sb);
 560         sb_free_blocks--;
 561         ext4_superblock_set_free_blocks_count(sb, sb_free_blocks);
 562
 563         /* Update inode blocks (different block size!) count */
 564         uint64_t ino_blocks =
 565             ext4_inode_get_blocks_count(sb, inode_ref->inode);
 566         ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
 567         ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 568         inode_ref->dirty = true;
 569
 570         /* Update block group free blocks count */
 571         uint32_t bg_free_blocks =
 572             ext4_block_group_get_free_blocks_count(bg_ref->block_group, sb);
 573         bg_free_blocks--;
 574         ext4_block_group_set_free_blocks_count(bg_ref->block_group, sb,
 575             bg_free_blocks);
 576         bg_ref->dirty = true;
 577
 578         ext4_filesystem_put_block_group_ref(bg_ref);
 579
 580         *fblock = allocated_block;
 581         return EOK;
 582 }
 583
 584 /** Try to allocate concrete block.
 585  *
 586  * @param inode_ref Inode to allocate block for
 587  * @param fblock    Block address to allocate
 588  * @param free      Output value - if target block is free
 589  *
 590  * @return Error code
 591  *
 592  */
 593 int ext4_balloc_try_alloc_block(ext4_inode_ref_t *inode_ref, uint32_t fblock,
 594     bool *free)
 595 {
 596         int rc = EOK;
 597
 598         ext4_filesystem_t *fs = inode_ref->fs;
 599         ext4_superblock_t *sb = fs->superblock;
 600
 601         /* Compute indexes */
 602         uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, fblock);
 603         uint32_t index_in_group =
 604             ext4_filesystem_blockaddr2_index_in_group(sb, fblock);
 605
 606         /* Load block group reference */
 607         ext4_block_group_ref_t *bg_ref;
 608         rc = ext4_filesystem_get_block_group_ref(fs, block_group, &bg_ref);
 609         if (rc != EOK)
 610                 return rc;
 611
 612         /* Load block with bitmap */
 613         uint32_t bitmap_block_addr =
 614             ext4_block_group_get_block_bitmap(bg_ref->block_group, sb);
 615         block_t *bitmap_block;
 616         rc = block_get(&bitmap_block, fs->device, bitmap_block_addr, 0);
 617         if (rc != EOK)
 618                 return rc;
 619
 620         /* Check if block is free */
 621         *free = ext4_bitmap_is_free_bit(bitmap_block->data, index_in_group);
 622
 623         /* Allocate block if possible */
 624         if (*free) {
 625                 ext4_bitmap_set_bit(bitmap_block->data, index_in_group);
 626                 bitmap_block->dirty = true;
 627         }
 628
 629         /* Release block with bitmap */
 630         rc = block_put(bitmap_block);
 631         if (rc != EOK) {
 632                 /* Error in saving bitmap */
 633                 ext4_filesystem_put_block_group_ref(bg_ref);
 634                 return rc;
 635         }
 636
 637         /* If block is not free, return */
 638         if (!(*free))
 639                 goto terminate;
 640
 641         uint32_t block_size = ext4_superblock_get_block_size(sb);
 642
 643         /* Update superblock free blocks count */
 644         uint32_t sb_free_blocks = ext4_superblock_get_free_blocks_count(sb);
 645         sb_free_blocks--;
 646         ext4_superblock_set_free_blocks_count(sb, sb_free_blocks);
 647
 648         /* Update inode blocks count */
 649         uint64_t ino_blocks =
 650             ext4_inode_get_blocks_count(sb, inode_ref->inode);
 651         ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
 652         ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 653         inode_ref->dirty = true;
 654
 655         /* Update block group free blocks count */
 656         uint32_t free_blocks =
 657             ext4_block_group_get_free_blocks_count(bg_ref->block_group, sb);
 658         free_blocks--;
 659         ext4_block_group_set_free_blocks_count(bg_ref->block_group,
 660             sb, free_blocks);
 661         bg_ref->dirty = true;
 662
 663 terminate:
 664         return ext4_filesystem_put_block_group_ref(bg_ref);
 665 }
 666
 667 /**
 668  * @}
 669  */