lwext4/ext4_balloc.c

   1 /*
   2  * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
   3  *
   4  *
   5  * HelenOS:
   6  * Copyright (c) 2012 Martin Sucha
   7  * Copyright (c) 2012 Frantisek Princ
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  *
  14  * - Redistributions of source code must retain the above copyright
  15  *   notice, this list of conditions and the following disclaimer.
  16  * - Redistributions in binary form must reproduce the above copyright
  17  *   notice, this list of conditions and the following disclaimer in the
  18  *   documentation and/or other materials provided with the distribution.
  19  * - The name of the author may not be used to endorse or promote products
  20  *   derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 /** @addtogroup lwext4
  35  * @{
  36  */
  37 /**
  38  * @file  ext4_balloc.c
  39  * @brief Physical block allocator.
  40  */
  41
  42 #include "ext4_config.h"
  43 #include "ext4_balloc.h"
  44 #include "ext4_super.h"
  45 #include "ext4_crc32c.h"
  46 #include "ext4_block_group.h"
  47 #include "ext4_fs.h"
  48 #include "ext4_bitmap.h"
  49 #include "ext4_inode.h"
  50
  51 /**@brief Compute number of block group from block address.
  52  * @param sb superblock pointer.
  53  * @param baddr Absolute address of block.
  54  * @return Block group index
  55  */
  56 uint32_t ext4_balloc_get_bgid_of_block(struct ext4_sblock *s,
  57                                        uint64_t baddr)
  58 {
  59         if (ext4_get32(s, first_data_block) && baddr)
  60                 baddr--;
  61
  62         return baddr / ext4_get32(s, blocks_per_group);
  63 }
  64
  65 /**@brief Compute the starting block address of a block group
  66  * @param sb   superblock pointer.
  67  * @param bgid block group index
  68  * @return Block address
  69  */
  70 uint64_t ext4_balloc_get_block_of_bgid(struct ext4_sblock *s,
  71                                        uint32_t bgid)
  72 {
  73         uint64_t baddr = 0;
  74         if (ext4_get32(s, first_data_block))
  75                 baddr++;
  76
  77         baddr += bgid * ext4_get32(s, blocks_per_group);
  78         return baddr;
  79 }
  80
  81 #if CONFIG_META_CSUM_ENABLE
  82 static uint32_t ext4_balloc_bitmap_csum(struct ext4_sblock *sb,
  83                                         void *bitmap)
  84 {
  85         uint32_t checksum = 0;
  86         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
  87                 uint32_t blocks_per_group = ext4_get32(sb, blocks_per_group);
  88
  89                 /* First calculate crc32 checksum against fs uuid */
  90                 checksum = ext4_crc32c(EXT4_CRC32_INIT, sb->uuid,
  91                                 sizeof(sb->uuid));
  92                 /* Then calculate crc32 checksum against block_group_desc */
  93                 checksum = ext4_crc32c(checksum, bitmap, blocks_per_group / 8);
  94         }
  95         return checksum;
  96 }
  97 #else
  98 #define ext4_balloc_bitmap_csum(...) 0
  99 #endif
 100
 101 void ext4_balloc_set_bitmap_csum(struct ext4_sblock *sb,
 102                                  struct ext4_bgroup *bg,
 103                                  void *bitmap __unused)
 104 {
 105         int desc_size = ext4_sb_get_desc_size(sb);
 106         uint32_t checksum = ext4_balloc_bitmap_csum(sb, bitmap);
 107         uint16_t lo_checksum = to_le16(checksum & 0xFFFF),
 108                  hi_checksum = to_le16(checksum >> 16);
 109
 110         if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 111                 return;
 112
 113         /* See if we need to assign a 32bit checksum */
 114         bg->block_bitmap_csum_lo = lo_checksum;
 115         if (desc_size == EXT4_MAX_BLOCK_GROUP_DESCRIPTOR_SIZE)
 116                 bg->block_bitmap_csum_hi = hi_checksum;
 117
 118 }
 119
 120 #if CONFIG_META_CSUM_ENABLE
 121 static bool
 122 ext4_balloc_verify_bitmap_csum(struct ext4_sblock *sb,
 123                                struct ext4_bgroup *bg,
 124                                void *bitmap __unused)
 125 {
 126         int desc_size = ext4_sb_get_desc_size(sb);
 127         uint32_t checksum = ext4_balloc_bitmap_csum(sb, bitmap);
 128         uint16_t lo_checksum = to_le16(checksum & 0xFFFF),
 129                  hi_checksum = to_le16(checksum >> 16);
 130
 131         if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 132                 return true;
 133
 134         if (bg->block_bitmap_csum_lo != lo_checksum)
 135                 return false;
 136
 137         if (desc_size == EXT4_MAX_BLOCK_GROUP_DESCRIPTOR_SIZE)
 138                 if (bg->block_bitmap_csum_hi != hi_checksum)
 139                         return false;
 140
 141         return true;
 142 }
 143 #else
 144 #define ext4_balloc_verify_bitmap_csum(...) true
 145 #endif
 146
 147 int ext4_balloc_free_block(struct ext4_inode_ref *inode_ref, ext4_fsblk_t baddr)
 148 {
 149         struct ext4_fs *fs = inode_ref->fs;
 150         struct ext4_sblock *sb = &fs->sb;
 151
 152         uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, baddr);
 153         uint32_t index_in_group = ext4_fs_addr_to_idx_bg(sb, baddr);
 154
 155         /* Load block group reference */
 156         struct ext4_block_group_ref bg_ref;
 157         int rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
 158         if (rc != EOK)
 159                 return rc;
 160
 161         struct ext4_bgroup *bg = bg_ref.block_group;
 162
 163         /* Load block with bitmap */
 164         ext4_fsblk_t bitmap_block_addr =
 165             ext4_bg_get_block_bitmap(bg, sb);
 166
 167         struct ext4_block bitmap_block;
 168
 169         rc = ext4_block_get(fs->bdev, &bitmap_block, bitmap_block_addr);
 170         if (rc != EOK) {
 171                 ext4_fs_put_block_group_ref(&bg_ref);
 172                 return rc;
 173         }
 174
 175         if (!ext4_balloc_verify_bitmap_csum(sb, bg, bitmap_block.data)) {
 176                 ext4_dbg(DEBUG_BALLOC,
 177                         DBG_WARN "Bitmap checksum failed."
 178                         "Group: %" PRIu32"\n",
 179                         bg_ref.index);
 180         }
 181
 182         /* Modify bitmap */
 183         ext4_bmap_bit_clr(bitmap_block.data, index_in_group);
 184         ext4_balloc_set_bitmap_csum(sb, bg, bitmap_block.data);
 185         bitmap_block.dirty = true;
 186
 187         /* Release block with bitmap */
 188         rc = ext4_block_set(fs->bdev, &bitmap_block);
 189         if (rc != EOK) {
 190                 /* Error in saving bitmap */
 191                 ext4_fs_put_block_group_ref(&bg_ref);
 192                 return rc;
 193         }
 194
 195         uint32_t block_size = ext4_sb_get_block_size(sb);
 196
 197         /* Update superblock free blocks count */
 198         uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
 199         sb_free_blocks++;
 200         ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
 201
 202         /* Update inode blocks count */
 203         uint64_t ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
 204         ino_blocks -= block_size / EXT4_INODE_BLOCK_SIZE;
 205         ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 206         inode_ref->dirty = true;
 207
 208         /* Update block group free blocks count */
 209         uint32_t free_blocks = ext4_bg_get_free_blocks_count(bg, sb);
 210         free_blocks++;
 211         ext4_bg_set_free_blocks_count(bg, sb, free_blocks);
 212
 213         bg_ref.dirty = true;
 214
 215         /* Release block group reference */
 216         return ext4_fs_put_block_group_ref(&bg_ref);
 217 }
 218
 219 int ext4_balloc_free_blocks(struct ext4_inode_ref *inode_ref, ext4_fsblk_t first,
 220                             uint32_t count)
 221 {
 222         int rc = EOK;
 223         struct ext4_fs *fs = inode_ref->fs;
 224         struct ext4_sblock *sb = &fs->sb;
 225
 226         /* Compute indexes */
 227         uint32_t bg_first = ext4_balloc_get_bgid_of_block(sb, first);
 228
 229         /* Compute indexes */
 230         uint32_t bg_last = ext4_balloc_get_bgid_of_block(sb, first + count - 1);
 231
 232         if (!ext4_sb_feature_incom(sb, EXT4_FINCOM_FLEX_BG)) {
 233                 /*It is not possible without flex_bg that blocks are continuous
 234                  * and and last block belongs to other bg.*/
 235                 if (bg_last != bg_first) {
 236                         ext4_dbg(DEBUG_BALLOC, DBG_WARN "FLEX_BG: disabled & "
 237                                 "bg_last: %"PRIu32" bg_first: %"PRIu32"\n",
 238                                 bg_last, bg_first);
 239                 }
 240         }
 241
 242         /* Load block group reference */
 243         struct ext4_block_group_ref bg_ref;
 244         while (bg_first <= bg_last) {
 245
 246                 rc = ext4_fs_get_block_group_ref(fs, bg_first, &bg_ref);
 247                 if (rc != EOK)
 248                         return rc;
 249
 250                 struct ext4_bgroup *bg = bg_ref.block_group;
 251
 252                 uint32_t idx_in_bg_first;
 253                 idx_in_bg_first = ext4_fs_addr_to_idx_bg(sb, first);
 254
 255                 /* Load block with bitmap */
 256                 ext4_fsblk_t bitmap_blk = ext4_bg_get_block_bitmap(bg, sb);
 257
 258                 struct ext4_block blk;
 259                 rc = ext4_block_get(fs->bdev, &blk, bitmap_blk);
 260                 if (rc != EOK) {
 261                         ext4_fs_put_block_group_ref(&bg_ref);
 262                         return rc;
 263                 }
 264
 265                 if (!ext4_balloc_verify_bitmap_csum(sb, bg, blk.data)) {
 266                         ext4_dbg(DEBUG_BALLOC,
 267                                 DBG_WARN "Bitmap checksum failed."
 268                                 "Group: %" PRIu32"\n",
 269                                 bg_ref.index);
 270                 }
 271                 uint32_t free_cnt;
 272                 free_cnt = ext4_sb_get_block_size(sb) * 8 - idx_in_bg_first;
 273
 274                 /*If last block, free only count blocks*/
 275                 free_cnt = count > free_cnt ? free_cnt : count;
 276
 277                 /* Modify bitmap */
 278                 ext4_bmap_bits_free(blk.data, idx_in_bg_first, free_cnt);
 279                 ext4_balloc_set_bitmap_csum(sb, bg, blk.data);
 280                 blk.dirty = true;
 281
 282                 count -= free_cnt;
 283                 first += free_cnt;
 284
 285                 /* Release block with bitmap */
 286                 rc = ext4_block_set(fs->bdev, &blk);
 287                 if (rc != EOK) {
 288                         ext4_fs_put_block_group_ref(&bg_ref);
 289                         return rc;
 290                 }
 291
 292                 uint32_t block_size = ext4_sb_get_block_size(sb);
 293
 294                 /* Update superblock free blocks count */
 295                 uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
 296                 sb_free_blocks += free_cnt;
 297                 ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
 298
 299                 /* Update inode blocks count */
 300                 uint64_t ino_blocks;
 301                 ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
 302                 ino_blocks -= free_cnt * (block_size / EXT4_INODE_BLOCK_SIZE);
 303                 ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 304                 inode_ref->dirty = true;
 305
 306                 /* Update block group free blocks count */
 307                 uint32_t free_blocks;
 308                 free_blocks = ext4_bg_get_free_blocks_count(bg, sb);
 309                 free_blocks += free_cnt;
 310                 ext4_bg_set_free_blocks_count(bg, sb, free_blocks);
 311                 bg_ref.dirty = true;
 312
 313                 /* Release block group reference */
 314                 rc = ext4_fs_put_block_group_ref(&bg_ref);
 315                 if (rc != EOK)
 316                         break;
 317
 318                 bg_first++;
 319         }
 320
 321         /*All blocks should be released*/
 322         ext4_assert(count == 0);
 323         return rc;
 324 }
 325
 326 int ext4_balloc_alloc_block(struct ext4_inode_ref *inode_ref,
 327                             ext4_fsblk_t goal,
 328                             ext4_fsblk_t *fblock)
 329 {
 330         ext4_fsblk_t alloc = 0;
 331         ext4_fsblk_t bmp_blk_adr;
 332         uint32_t rel_blk_idx = 0;
 333         uint64_t free_blocks;
 334         int r;
 335         struct ext4_sblock *sb = &inode_ref->fs->sb;
 336
 337         /* Load block group number for goal and relative index */
 338         uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, goal);
 339         uint32_t idx_in_bg = ext4_fs_addr_to_idx_bg(sb, goal);
 340
 341         struct ext4_block b;
 342         struct ext4_block_group_ref bg_ref;
 343
 344         /* Load block group reference */
 345         r = ext4_fs_get_block_group_ref(inode_ref->fs, block_group, &bg_ref);
 346         if (r != EOK)
 347                 return r;
 348
 349         struct ext4_bgroup *bg = bg_ref.block_group;
 350
 351         free_blocks = ext4_bg_get_free_blocks_count(bg_ref.block_group, sb);
 352         if (free_blocks == 0) {
 353                 /* This group has no free blocks */
 354                 goto goal_failed;
 355         }
 356
 357         /* Compute indexes */
 358         ext4_fsblk_t first_in_bg;
 359         first_in_bg = ext4_balloc_get_block_of_bgid(sb, bg_ref.index);
 360
 361         uint32_t first_in_bg_index;
 362         first_in_bg_index = ext4_fs_addr_to_idx_bg(sb, first_in_bg);
 363
 364         if (idx_in_bg < first_in_bg_index)
 365                 idx_in_bg = first_in_bg_index;
 366
 367         /* Load block with bitmap */
 368         bmp_blk_adr = ext4_bg_get_block_bitmap(bg_ref.block_group, sb);
 369
 370         r = ext4_block_get(inode_ref->fs->bdev, &b, bmp_blk_adr);
 371         if (r != EOK) {
 372                 ext4_fs_put_block_group_ref(&bg_ref);
 373                 return r;
 374         }
 375
 376         if (!ext4_balloc_verify_bitmap_csum(sb, bg, b.data)) {
 377                 ext4_dbg(DEBUG_BALLOC,
 378                         DBG_WARN "Bitmap checksum failed."
 379                         "Group: %" PRIu32"\n",
 380                         bg_ref.index);
 381         }
 382
 383         /* Check if goal is free */
 384         if (ext4_bmap_is_bit_clr(b.data, idx_in_bg)) {
 385                 ext4_bmap_bit_set(b.data, idx_in_bg);
 386                 ext4_balloc_set_bitmap_csum(sb, bg_ref.block_group,
 387                                             b.data);
 388                 b.dirty = true;
 389                 r = ext4_block_set(inode_ref->fs->bdev, &b);
 390                 if (r != EOK) {
 391                         ext4_fs_put_block_group_ref(&bg_ref);
 392                         return r;
 393                 }
 394
 395                 alloc = ext4_fs_bg_idx_to_addr(sb, idx_in_bg, block_group);
 396                 goto success;
 397         }
 398
 399         uint32_t blk_in_bg = ext4_blocks_in_group_cnt(sb, block_group);
 400
 401         uint32_t end_idx = (idx_in_bg + 63) & ~63;
 402         if (end_idx > blk_in_bg)
 403                 end_idx = blk_in_bg;
 404
 405         /* Try to find free block near to goal */
 406         uint32_t tmp_idx;
 407         for (tmp_idx = idx_in_bg + 1; tmp_idx < end_idx; ++tmp_idx) {
 408                 if (ext4_bmap_is_bit_clr(b.data, tmp_idx)) {
 409                         ext4_bmap_bit_set(b.data, tmp_idx);
 410
 411                         ext4_balloc_set_bitmap_csum(sb, bg, b.data);
 412                         b.dirty = true;
 413                         r = ext4_block_set(inode_ref->fs->bdev, &b);
 414                         if (r != EOK)
 415                                 return r;
 416
 417                         alloc = ext4_fs_bg_idx_to_addr(sb, tmp_idx, block_group);
 418                         goto success;
 419                 }
 420         }
 421
 422         /* Find free bit in bitmap */
 423         r = ext4_bmap_bit_find_clr(b.data, idx_in_bg, blk_in_bg, &rel_blk_idx);
 424         if (r == EOK) {
 425                 ext4_bmap_bit_set(b.data, rel_blk_idx);
 426                 ext4_balloc_set_bitmap_csum(sb, bg_ref.block_group, b.data);
 427                 b.dirty = true;
 428                 r = ext4_block_set(inode_ref->fs->bdev, &b);
 429                 if (r != EOK)
 430                         return r;
 431
 432                 alloc = ext4_fs_bg_idx_to_addr(sb, rel_blk_idx, block_group);
 433                 goto success;
 434         }
 435
 436         /* No free block found yet */
 437         r = ext4_block_set(inode_ref->fs->bdev, &b);
 438         if (r != EOK) {
 439                 ext4_fs_put_block_group_ref(&bg_ref);
 440                 return r;
 441         }
 442
 443 goal_failed:
 444
 445         r = ext4_fs_put_block_group_ref(&bg_ref);
 446         if (r != EOK)
 447                 return r;
 448
 449         /* Try other block groups */
 450         uint32_t block_group_count = ext4_block_group_cnt(sb);
 451         uint32_t bgid = (block_group + 1) % block_group_count;
 452         uint32_t count = block_group_count;
 453
 454         while (count > 0) {
 455                 r = ext4_fs_get_block_group_ref(inode_ref->fs, bgid, &bg_ref);
 456                 if (r != EOK)
 457                         return r;
 458
 459                 struct ext4_bgroup *bg = bg_ref.block_group;
 460                 free_blocks = ext4_bg_get_free_blocks_count(bg, sb);
 461                 if (free_blocks == 0) {
 462                         /* This group has no free blocks */
 463                         goto next_group;
 464                 }
 465
 466                 /* Load block with bitmap */
 467                 bmp_blk_adr = ext4_bg_get_block_bitmap(bg, sb);
 468                 r = ext4_block_get(inode_ref->fs->bdev, &b, bmp_blk_adr);
 469                 if (r != EOK) {
 470                         ext4_fs_put_block_group_ref(&bg_ref);
 471                         return r;
 472                 }
 473
 474                 if (!ext4_balloc_verify_bitmap_csum(sb, bg, b.data)) {
 475                         ext4_dbg(DEBUG_BALLOC,
 476                                 DBG_WARN "Bitmap checksum failed."
 477                                 "Group: %" PRIu32"\n",
 478                                 bg_ref.index);
 479                 }
 480
 481                 /* Compute indexes */
 482                 first_in_bg = ext4_balloc_get_block_of_bgid(sb, bgid);
 483                 idx_in_bg = ext4_fs_addr_to_idx_bg(sb, first_in_bg);
 484                 blk_in_bg = ext4_blocks_in_group_cnt(sb, bgid);
 485                 first_in_bg_index = ext4_fs_addr_to_idx_bg(sb, first_in_bg);
 486
 487                 if (idx_in_bg < first_in_bg_index)
 488                         idx_in_bg = first_in_bg_index;
 489
 490                 r = ext4_bmap_bit_find_clr(b.data, idx_in_bg, blk_in_bg,
 491                                 &rel_blk_idx);
 492                 if (r == EOK) {
 493                         ext4_bmap_bit_set(b.data, rel_blk_idx);
 494                         ext4_balloc_set_bitmap_csum(sb, bg, b.data);
 495                         b.dirty = true;
 496                         r = ext4_block_set(inode_ref->fs->bdev, &b);
 497                         if (r != EOK) {
 498                                 ext4_fs_put_block_group_ref(&bg_ref);
 499                                 return r;
 500                         }
 501
 502                         alloc = ext4_fs_bg_idx_to_addr(sb, rel_blk_idx, bgid);
 503                         goto success;
 504                 }
 505
 506                 r = ext4_block_set(inode_ref->fs->bdev, &b);
 507                 if (r != EOK) {
 508                         ext4_fs_put_block_group_ref(&bg_ref);
 509                         return r;
 510                 }
 511
 512         next_group:
 513                 r = ext4_fs_put_block_group_ref(&bg_ref);
 514                 if (r != EOK) {
 515                         return r;
 516                 }
 517
 518                 /* Goto next group */
 519                 bgid = (bgid + 1) % block_group_count;
 520                 count--;
 521         }
 522
 523         return ENOSPC;
 524
 525 success:
 526     /* Empty command - because of syntax */
 527     ;
 528
 529         uint32_t block_size = ext4_sb_get_block_size(sb);
 530
 531         /* Update superblock free blocks count */
 532         uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
 533         sb_free_blocks--;
 534         ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
 535
 536         /* Update inode blocks (different block size!) count */
 537         uint64_t ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
 538         ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
 539         ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 540         inode_ref->dirty = true;
 541
 542         /* Update block group free blocks count */
 543
 544         uint32_t fb_cnt = ext4_bg_get_free_blocks_count(bg_ref.block_group, sb);
 545         fb_cnt--;
 546         ext4_bg_set_free_blocks_count(bg_ref.block_group, sb, fb_cnt);
 547
 548         bg_ref.dirty = true;
 549         r = ext4_fs_put_block_group_ref(&bg_ref);
 550
 551         *fblock = alloc;
 552         return r;
 553 }
 554
 555 int ext4_balloc_try_alloc_block(struct ext4_inode_ref *inode_ref,
 556                                 ext4_fsblk_t baddr, bool *free)
 557 {
 558         int rc;
 559
 560         struct ext4_fs *fs = inode_ref->fs;
 561         struct ext4_sblock *sb = &fs->sb;
 562
 563         /* Compute indexes */
 564         uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, baddr);
 565         uint32_t index_in_group = ext4_fs_addr_to_idx_bg(sb, baddr);
 566
 567         /* Load block group reference */
 568         struct ext4_block_group_ref bg_ref;
 569         rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
 570         if (rc != EOK)
 571                 return rc;
 572
 573         /* Load block with bitmap */
 574         ext4_fsblk_t bmp_blk_addr;
 575         bmp_blk_addr = ext4_bg_get_block_bitmap(bg_ref.block_group, sb);
 576
 577         struct ext4_block b;
 578         rc = ext4_block_get(fs->bdev, &b, bmp_blk_addr);
 579         if (rc != EOK) {
 580                 ext4_fs_put_block_group_ref(&bg_ref);
 581                 return rc;
 582         }
 583
 584         if (!ext4_balloc_verify_bitmap_csum(sb, bg_ref.block_group, b.data)) {
 585                 ext4_dbg(DEBUG_BALLOC,
 586                         DBG_WARN "Bitmap checksum failed."
 587                         "Group: %" PRIu32"\n",
 588                         bg_ref.index);
 589         }
 590
 591         /* Check if block is free */
 592         *free = ext4_bmap_is_bit_clr(b.data, index_in_group);
 593
 594         /* Allocate block if possible */
 595         if (*free) {
 596                 ext4_bmap_bit_set(b.data, index_in_group);
 597                 ext4_balloc_set_bitmap_csum(sb, bg_ref.block_group, b.data);
 598                 b.dirty = true;
 599         }
 600
 601         /* Release block with bitmap */
 602         rc = ext4_block_set(fs->bdev, &b);
 603         if (rc != EOK) {
 604                 /* Error in saving bitmap */
 605                 ext4_fs_put_block_group_ref(&bg_ref);
 606                 return rc;
 607         }
 608
 609         /* If block is not free, return */
 610         if (!(*free))
 611                 goto terminate;
 612
 613         uint32_t block_size = ext4_sb_get_block_size(sb);
 614
 615         /* Update superblock free blocks count */
 616         uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
 617         sb_free_blocks--;
 618         ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
 619
 620         /* Update inode blocks count */
 621         uint64_t ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
 622         ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
 623         ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 624         inode_ref->dirty = true;
 625
 626         /* Update block group free blocks count */
 627         uint32_t fb_cnt = ext4_bg_get_free_blocks_count(bg_ref.block_group, sb);
 628         fb_cnt--;
 629         ext4_bg_set_free_blocks_count(bg_ref.block_group, sb, fb_cnt);
 630
 631         bg_ref.dirty = true;
 632
 633 terminate:
 634         return ext4_fs_put_block_group_ref(&bg_ref);
 635 }
 636
 637 /**
 638  * @}
 639  */