src/ext4_balloc.c

   1 /*
   2  * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
   3  *
   4  * HelenOS:
   5  * Copyright (c) 2012 Martin Sucha
   6  * Copyright (c) 2012 Frantisek Princ
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * - Redistributions of source code must retain the above copyright
  14  *   notice, this list of conditions and the following disclaimer.
  15  * - Redistributions in binary form must reproduce the above copyright
  16  *   notice, this list of conditions and the following disclaimer in the
  17  *   documentation and/or other materials provided with the distribution.
  18  * - The name of the author may not be used to endorse or promote products
  19  *   derived from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  */
  32
  33 /** @addtogroup lwext4
  34  * @{
  35  */
  36 /**
  37  * @file  ext4_balloc.c
  38  * @brief Physical block allocator.
  39  */
  40
  41 #include "ext4_config.h"
  42 #include "ext4_types.h"
  43 #include "ext4_misc.h"
  44 #include "ext4_errno.h"
  45 #include "ext4_debug.h"
  46
  47 #include "ext4_trans.h"
  48 #include "ext4_balloc.h"
  49 #include "ext4_super.h"
  50 #include "ext4_crc32.h"
  51 #include "ext4_block_group.h"
  52 #include "ext4_fs.h"
  53 #include "ext4_bitmap.h"
  54 #include "ext4_inode.h"
  55
  56 /**@brief Compute number of block group from block address.
  57  * @param sb superblock pointer.
  58  * @param baddr Absolute address of block.
  59  * @return Block group index
  60  */
  61 uint32_t ext4_balloc_get_bgid_of_block(struct ext4_sblock *s,
  62                                        uint64_t baddr)
  63 {
  64         if (ext4_get32(s, first_data_block) && baddr)
  65                 baddr--;
  66
  67         return (uint32_t)(baddr / ext4_get32(s, blocks_per_group));
  68 }
  69
  70 /**@brief Compute the starting block address of a block group
  71  * @param sb   superblock pointer.
  72  * @param bgid block group index
  73  * @return Block address
  74  */
  75 uint64_t ext4_balloc_get_block_of_bgid(struct ext4_sblock *s,
  76                                        uint32_t bgid)
  77 {
  78         uint64_t baddr = 0;
  79         if (ext4_get32(s, first_data_block))
  80                 baddr++;
  81
  82         baddr += bgid * ext4_get32(s, blocks_per_group);
  83         return baddr;
  84 }
  85
  86 #if CONFIG_META_CSUM_ENABLE
  87 static uint32_t ext4_balloc_bitmap_csum(struct ext4_sblock *sb,
  88                                         void *bitmap)
  89 {
  90         uint32_t checksum = 0;
  91         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
  92                 uint32_t blocks_per_group = ext4_get32(sb, blocks_per_group);
  93
  94                 /* First calculate crc32 checksum against fs uuid */
  95                 checksum = ext4_crc32c(EXT4_CRC32_INIT, sb->uuid,
  96                                 sizeof(sb->uuid));
  97                 /* Then calculate crc32 checksum against block_group_desc */
  98                 checksum = ext4_crc32c(checksum, bitmap, blocks_per_group / 8);
  99         }
 100         return checksum;
 101 }
 102 #else
 103 #define ext4_balloc_bitmap_csum(...) 0
 104 #endif
 105
 106 void ext4_balloc_set_bitmap_csum(struct ext4_sblock *sb,
 107                                  struct ext4_bgroup *bg,
 108                                  void *bitmap __unused)
 109 {
 110         int desc_size = ext4_sb_get_desc_size(sb);
 111         uint32_t checksum = ext4_balloc_bitmap_csum(sb, bitmap);
 112         uint16_t lo_checksum = to_le16(checksum & 0xFFFF),
 113                  hi_checksum = to_le16(checksum >> 16);
 114
 115         if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 116                 return;
 117
 118         /* See if we need to assign a 32bit checksum */
 119         bg->block_bitmap_csum_lo = lo_checksum;
 120         if (desc_size == EXT4_MAX_BLOCK_GROUP_DESCRIPTOR_SIZE)
 121                 bg->block_bitmap_csum_hi = hi_checksum;
 122
 123 }
 124
 125 #if CONFIG_META_CSUM_ENABLE
 126 static bool
 127 ext4_balloc_verify_bitmap_csum(struct ext4_sblock *sb,
 128                                struct ext4_bgroup *bg,
 129                                void *bitmap __unused)
 130 {
 131         int desc_size = ext4_sb_get_desc_size(sb);
 132         uint32_t checksum = ext4_balloc_bitmap_csum(sb, bitmap);
 133         uint16_t lo_checksum = to_le16(checksum & 0xFFFF),
 134                  hi_checksum = to_le16(checksum >> 16);
 135
 136         if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 137                 return true;
 138
 139         if (bg->block_bitmap_csum_lo != lo_checksum)
 140                 return false;
 141
 142         if (desc_size == EXT4_MAX_BLOCK_GROUP_DESCRIPTOR_SIZE)
 143                 if (bg->block_bitmap_csum_hi != hi_checksum)
 144                         return false;
 145
 146         return true;
 147 }
 148 #else
 149 #define ext4_balloc_verify_bitmap_csum(...) true
 150 #endif
 151
 152 int ext4_balloc_free_block(struct ext4_inode_ref *inode_ref, ext4_fsblk_t baddr)
 153 {
 154         struct ext4_fs *fs = inode_ref->fs;
 155         struct ext4_sblock *sb = &fs->sb;
 156
 157         uint32_t bg_id = ext4_balloc_get_bgid_of_block(sb, baddr);
 158         uint32_t index_in_group = ext4_fs_addr_to_idx_bg(sb, baddr);
 159
 160         /* Load block group reference */
 161         struct ext4_block_group_ref bg_ref;
 162         int rc = ext4_fs_get_block_group_ref(fs, bg_id, &bg_ref);
 163         if (rc != EOK)
 164                 return rc;
 165
 166         struct ext4_bgroup *bg = bg_ref.block_group;
 167
 168         /* Load block with bitmap */
 169         ext4_fsblk_t bitmap_block_addr =
 170             ext4_bg_get_block_bitmap(bg, sb);
 171
 172         struct ext4_block bitmap_block;
 173
 174         rc = ext4_trans_block_get(fs->bdev, &bitmap_block, bitmap_block_addr);
 175         if (rc != EOK) {
 176                 ext4_fs_put_block_group_ref(&bg_ref);
 177                 return rc;
 178         }
 179
 180         if (!ext4_balloc_verify_bitmap_csum(sb, bg, bitmap_block.data)) {
 181                 ext4_dbg(DEBUG_BALLOC,
 182                         DBG_WARN "Bitmap checksum failed."
 183                         "Group: %" PRIu32"\n",
 184                         bg_ref.index);
 185         }
 186
 187         /* Modify bitmap */
 188         ext4_bmap_bit_clr(bitmap_block.data, index_in_group);
 189         ext4_balloc_set_bitmap_csum(sb, bg, bitmap_block.data);
 190         ext4_trans_set_block_dirty(bitmap_block.buf);
 191
 192         /* Release block with bitmap */
 193         rc = ext4_block_set(fs->bdev, &bitmap_block);
 194         if (rc != EOK) {
 195                 /* Error in saving bitmap */
 196                 ext4_fs_put_block_group_ref(&bg_ref);
 197                 return rc;
 198         }
 199
 200         uint32_t block_size = ext4_sb_get_block_size(sb);
 201
 202         /* Update superblock free blocks count */
 203         uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
 204         sb_free_blocks++;
 205         ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
 206
 207         /* Update inode blocks count */
 208         uint64_t ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
 209         ino_blocks -= block_size / EXT4_INODE_BLOCK_SIZE;
 210         ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 211         inode_ref->dirty = true;
 212
 213         /* Update block group free blocks count */
 214         uint32_t free_blocks = ext4_bg_get_free_blocks_count(bg, sb);
 215         free_blocks++;
 216         ext4_bg_set_free_blocks_count(bg, sb, free_blocks);
 217
 218         bg_ref.dirty = true;
 219
 220         rc = ext4_trans_try_revoke_block(fs->bdev, baddr);
 221         if (rc != EOK) {
 222                 bg_ref.dirty = false;
 223                 ext4_fs_put_block_group_ref(&bg_ref);
 224                 return rc;
 225         }
 226         ext4_bcache_invalidate_lba(fs->bdev->bc, baddr, 1);
 227         /* Release block group reference */
 228         return ext4_fs_put_block_group_ref(&bg_ref);
 229 }
 230
 231 int ext4_balloc_free_blocks(struct ext4_inode_ref *inode_ref,
 232                             ext4_fsblk_t first, uint32_t count)
 233 {
 234         int rc = EOK;
 235         uint32_t blk_cnt = count;
 236         struct ext4_fs *fs = inode_ref->fs;
 237         struct ext4_sblock *sb = &fs->sb;
 238
 239         /* Compute indexes */
 240         uint32_t bg_first = ext4_balloc_get_bgid_of_block(sb, first);
 241
 242         /* Compute indexes */
 243         uint32_t bg_last = ext4_balloc_get_bgid_of_block(sb, first + count - 1);
 244
 245         if (!ext4_sb_feature_incom(sb, EXT4_FINCOM_FLEX_BG)) {
 246                 /*It is not possible without flex_bg that blocks are continuous
 247                  * and and last block belongs to other bg.*/
 248                 if (bg_last != bg_first) {
 249                         ext4_dbg(DEBUG_BALLOC, DBG_WARN "FLEX_BG: disabled & "
 250                                 "bg_last: %"PRIu32" bg_first: %"PRIu32"\n",
 251                                 bg_last, bg_first);
 252                 }
 253         }
 254
 255         /* Load block group reference */
 256         struct ext4_block_group_ref bg_ref;
 257         while (bg_first <= bg_last) {
 258
 259                 rc = ext4_fs_get_block_group_ref(fs, bg_first, &bg_ref);
 260                 if (rc != EOK)
 261                         return rc;
 262
 263                 struct ext4_bgroup *bg = bg_ref.block_group;
 264
 265                 uint32_t idx_in_bg_first;
 266                 idx_in_bg_first = ext4_fs_addr_to_idx_bg(sb, first);
 267
 268                 /* Load block with bitmap */
 269                 ext4_fsblk_t bitmap_blk = ext4_bg_get_block_bitmap(bg, sb);
 270
 271                 struct ext4_block blk;
 272                 rc = ext4_trans_block_get(fs->bdev, &blk, bitmap_blk);
 273                 if (rc != EOK) {
 274                         ext4_fs_put_block_group_ref(&bg_ref);
 275                         return rc;
 276                 }
 277
 278                 if (!ext4_balloc_verify_bitmap_csum(sb, bg, blk.data)) {
 279                         ext4_dbg(DEBUG_BALLOC,
 280                                 DBG_WARN "Bitmap checksum failed."
 281                                 "Group: %" PRIu32"\n",
 282                                 bg_ref.index);
 283                 }
 284                 uint32_t free_cnt;
 285                 free_cnt = ext4_sb_get_block_size(sb) * 8 - idx_in_bg_first;
 286
 287                 /*If last block, free only count blocks*/
 288                 free_cnt = count > free_cnt ? free_cnt : count;
 289
 290                 /* Modify bitmap */
 291                 ext4_bmap_bits_free(blk.data, idx_in_bg_first, free_cnt);
 292                 ext4_balloc_set_bitmap_csum(sb, bg, blk.data);
 293                 ext4_trans_set_block_dirty(blk.buf);
 294
 295                 count -= free_cnt;
 296                 first += free_cnt;
 297
 298                 /* Release block with bitmap */
 299                 rc = ext4_block_set(fs->bdev, &blk);
 300                 if (rc != EOK) {
 301                         ext4_fs_put_block_group_ref(&bg_ref);
 302                         return rc;
 303                 }
 304
 305                 uint32_t block_size = ext4_sb_get_block_size(sb);
 306
 307                 /* Update superblock free blocks count */
 308                 uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
 309                 sb_free_blocks += free_cnt;
 310                 ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
 311
 312                 /* Update inode blocks count */
 313                 uint64_t ino_blocks;
 314                 ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
 315                 ino_blocks -= free_cnt * (block_size / EXT4_INODE_BLOCK_SIZE);
 316                 ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 317                 inode_ref->dirty = true;
 318
 319                 /* Update block group free blocks count */
 320                 uint32_t free_blocks;
 321                 free_blocks = ext4_bg_get_free_blocks_count(bg, sb);
 322                 free_blocks += free_cnt;
 323                 ext4_bg_set_free_blocks_count(bg, sb, free_blocks);
 324                 bg_ref.dirty = true;
 325
 326                 /* Release block group reference */
 327                 rc = ext4_fs_put_block_group_ref(&bg_ref);
 328                 if (rc != EOK)
 329                         break;
 330
 331                 bg_first++;
 332         }
 333
 334         uint32_t i;
 335         for (i = 0;i < blk_cnt;i++) {
 336                 rc = ext4_trans_try_revoke_block(fs->bdev, first + i);
 337                 if (rc != EOK)
 338                         return rc;
 339
 340         }
 341
 342         ext4_bcache_invalidate_lba(fs->bdev->bc, first, count);
 343         /*All blocks should be released*/
 344         ext4_assert(count == 0);
 345         return rc;
 346 }
 347
 348 int ext4_balloc_alloc_block(struct ext4_inode_ref *inode_ref,
 349                             ext4_fsblk_t goal,
 350                             ext4_fsblk_t *fblock)
 351 {
 352         ext4_fsblk_t alloc = 0;
 353         ext4_fsblk_t bmp_blk_adr;
 354         uint32_t rel_blk_idx = 0;
 355         uint64_t free_blocks;
 356         int r;
 357         struct ext4_sblock *sb = &inode_ref->fs->sb;
 358
 359         /* Load block group number for goal and relative index */
 360         uint32_t bg_id = ext4_balloc_get_bgid_of_block(sb, goal);
 361         uint32_t idx_in_bg = ext4_fs_addr_to_idx_bg(sb, goal);
 362
 363         struct ext4_block b;
 364         struct ext4_block_group_ref bg_ref;
 365
 366         /* Load block group reference */
 367         r = ext4_fs_get_block_group_ref(inode_ref->fs, bg_id, &bg_ref);
 368         if (r != EOK)
 369                 return r;
 370
 371         struct ext4_bgroup *bg = bg_ref.block_group;
 372
 373         free_blocks = ext4_bg_get_free_blocks_count(bg_ref.block_group, sb);
 374         if (free_blocks == 0) {
 375                 /* This group has no free blocks */
 376                 goto goal_failed;
 377         }
 378
 379         /* Compute indexes */
 380         ext4_fsblk_t first_in_bg;
 381         first_in_bg = ext4_balloc_get_block_of_bgid(sb, bg_ref.index);
 382
 383         uint32_t first_in_bg_index;
 384         first_in_bg_index = ext4_fs_addr_to_idx_bg(sb, first_in_bg);
 385
 386         if (idx_in_bg < first_in_bg_index)
 387                 idx_in_bg = first_in_bg_index;
 388
 389         /* Load block with bitmap */
 390         bmp_blk_adr = ext4_bg_get_block_bitmap(bg_ref.block_group, sb);
 391
 392         r = ext4_trans_block_get(inode_ref->fs->bdev, &b, bmp_blk_adr);
 393         if (r != EOK) {
 394                 ext4_fs_put_block_group_ref(&bg_ref);
 395                 return r;
 396         }
 397
 398         if (!ext4_balloc_verify_bitmap_csum(sb, bg, b.data)) {
 399                 ext4_dbg(DEBUG_BALLOC,
 400                         DBG_WARN "Bitmap checksum failed."
 401                         "Group: %" PRIu32"\n",
 402                         bg_ref.index);
 403         }
 404
 405         /* Check if goal is free */
 406         if (ext4_bmap_is_bit_clr(b.data, idx_in_bg)) {
 407                 ext4_bmap_bit_set(b.data, idx_in_bg);
 408                 ext4_balloc_set_bitmap_csum(sb, bg_ref.block_group,
 409                                             b.data);
 410                 ext4_trans_set_block_dirty(b.buf);
 411                 r = ext4_block_set(inode_ref->fs->bdev, &b);
 412                 if (r != EOK) {
 413                         ext4_fs_put_block_group_ref(&bg_ref);
 414                         return r;
 415                 }
 416
 417                 alloc = ext4_fs_bg_idx_to_addr(sb, idx_in_bg, bg_id);
 418                 goto success;
 419         }
 420
 421         uint32_t blk_in_bg = ext4_blocks_in_group_cnt(sb, bg_id);
 422
 423         uint32_t end_idx = (idx_in_bg + 63) & ~63;
 424         if (end_idx > blk_in_bg)
 425                 end_idx = blk_in_bg;
 426
 427         /* Try to find free block near to goal */
 428         uint32_t tmp_idx;
 429         for (tmp_idx = idx_in_bg + 1; tmp_idx < end_idx; ++tmp_idx) {
 430                 if (ext4_bmap_is_bit_clr(b.data, tmp_idx)) {
 431                         ext4_bmap_bit_set(b.data, tmp_idx);
 432
 433                         ext4_balloc_set_bitmap_csum(sb, bg, b.data);
 434                         ext4_trans_set_block_dirty(b.buf);
 435                         r = ext4_block_set(inode_ref->fs->bdev, &b);
 436                         if (r != EOK)
 437                                 return r;
 438
 439                         alloc = ext4_fs_bg_idx_to_addr(sb, tmp_idx, bg_id);
 440                         goto success;
 441                 }
 442         }
 443
 444         /* Find free bit in bitmap */
 445         r = ext4_bmap_bit_find_clr(b.data, idx_in_bg, blk_in_bg, &rel_blk_idx);
 446         if (r == EOK) {
 447                 ext4_bmap_bit_set(b.data, rel_blk_idx);
 448                 ext4_balloc_set_bitmap_csum(sb, bg_ref.block_group, b.data);
 449                 ext4_trans_set_block_dirty(b.buf);
 450                 r = ext4_block_set(inode_ref->fs->bdev, &b);
 451                 if (r != EOK)
 452                         return r;
 453
 454                 alloc = ext4_fs_bg_idx_to_addr(sb, rel_blk_idx, bg_id);
 455                 goto success;
 456         }
 457
 458         /* No free block found yet */
 459         r = ext4_block_set(inode_ref->fs->bdev, &b);
 460         if (r != EOK) {
 461                 ext4_fs_put_block_group_ref(&bg_ref);
 462                 return r;
 463         }
 464
 465 goal_failed:
 466
 467         r = ext4_fs_put_block_group_ref(&bg_ref);
 468         if (r != EOK)
 469                 return r;
 470
 471         /* Try other block groups */
 472         uint32_t block_group_count = ext4_block_group_cnt(sb);
 473         uint32_t bgid = (bg_id + 1) % block_group_count;
 474         uint32_t count = block_group_count;
 475
 476         while (count > 0) {
 477                 r = ext4_fs_get_block_group_ref(inode_ref->fs, bgid, &bg_ref);
 478                 if (r != EOK)
 479                         return r;
 480
 481                 struct ext4_bgroup *bg = bg_ref.block_group;
 482                 free_blocks = ext4_bg_get_free_blocks_count(bg, sb);
 483                 if (free_blocks == 0) {
 484                         /* This group has no free blocks */
 485                         goto next_group;
 486                 }
 487
 488                 /* Load block with bitmap */
 489                 bmp_blk_adr = ext4_bg_get_block_bitmap(bg, sb);
 490                 r = ext4_trans_block_get(inode_ref->fs->bdev, &b, bmp_blk_adr);
 491                 if (r != EOK) {
 492                         ext4_fs_put_block_group_ref(&bg_ref);
 493                         return r;
 494                 }
 495
 496                 if (!ext4_balloc_verify_bitmap_csum(sb, bg, b.data)) {
 497                         ext4_dbg(DEBUG_BALLOC,
 498                                 DBG_WARN "Bitmap checksum failed."
 499                                 "Group: %" PRIu32"\n",
 500                                 bg_ref.index);
 501                 }
 502
 503                 /* Compute indexes */
 504                 first_in_bg = ext4_balloc_get_block_of_bgid(sb, bgid);
 505                 idx_in_bg = ext4_fs_addr_to_idx_bg(sb, first_in_bg);
 506                 blk_in_bg = ext4_blocks_in_group_cnt(sb, bgid);
 507                 first_in_bg_index = ext4_fs_addr_to_idx_bg(sb, first_in_bg);
 508
 509                 if (idx_in_bg < first_in_bg_index)
 510                         idx_in_bg = first_in_bg_index;
 511
 512                 r = ext4_bmap_bit_find_clr(b.data, idx_in_bg, blk_in_bg,
 513                                 &rel_blk_idx);
 514                 if (r == EOK) {
 515                         ext4_bmap_bit_set(b.data, rel_blk_idx);
 516                         ext4_balloc_set_bitmap_csum(sb, bg, b.data);
 517                         ext4_trans_set_block_dirty(b.buf);
 518                         r = ext4_block_set(inode_ref->fs->bdev, &b);
 519                         if (r != EOK) {
 520                                 ext4_fs_put_block_group_ref(&bg_ref);
 521                                 return r;
 522                         }
 523
 524                         alloc = ext4_fs_bg_idx_to_addr(sb, rel_blk_idx, bgid);
 525                         goto success;
 526                 }
 527
 528                 r = ext4_block_set(inode_ref->fs->bdev, &b);
 529                 if (r != EOK) {
 530                         ext4_fs_put_block_group_ref(&bg_ref);
 531                         return r;
 532                 }
 533
 534         next_group:
 535                 r = ext4_fs_put_block_group_ref(&bg_ref);
 536                 if (r != EOK) {
 537                         return r;
 538                 }
 539
 540                 /* Goto next group */
 541                 bgid = (bgid + 1) % block_group_count;
 542                 count--;
 543         }
 544
 545         return ENOSPC;
 546
 547 success:
 548     /* Empty command - because of syntax */
 549     ;
 550
 551         uint32_t block_size = ext4_sb_get_block_size(sb);
 552
 553         /* Update superblock free blocks count */
 554         uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
 555         sb_free_blocks--;
 556         ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
 557
 558         /* Update inode blocks (different block size!) count */
 559         uint64_t ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
 560         ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
 561         ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 562         inode_ref->dirty = true;
 563
 564         /* Update block group free blocks count */
 565
 566         uint32_t fb_cnt = ext4_bg_get_free_blocks_count(bg_ref.block_group, sb);
 567         fb_cnt--;
 568         ext4_bg_set_free_blocks_count(bg_ref.block_group, sb, fb_cnt);
 569
 570         bg_ref.dirty = true;
 571         r = ext4_fs_put_block_group_ref(&bg_ref);
 572
 573         *fblock = alloc;
 574         return r;
 575 }
 576
 577 int ext4_balloc_try_alloc_block(struct ext4_inode_ref *inode_ref,
 578                                 ext4_fsblk_t baddr, bool *free)
 579 {
 580         int rc;
 581
 582         struct ext4_fs *fs = inode_ref->fs;
 583         struct ext4_sblock *sb = &fs->sb;
 584
 585         /* Compute indexes */
 586         uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, baddr);
 587         uint32_t index_in_group = ext4_fs_addr_to_idx_bg(sb, baddr);
 588
 589         /* Load block group reference */
 590         struct ext4_block_group_ref bg_ref;
 591         rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
 592         if (rc != EOK)
 593                 return rc;
 594
 595         /* Load block with bitmap */
 596         ext4_fsblk_t bmp_blk_addr;
 597         bmp_blk_addr = ext4_bg_get_block_bitmap(bg_ref.block_group, sb);
 598
 599         struct ext4_block b;
 600         rc = ext4_trans_block_get(fs->bdev, &b, bmp_blk_addr);
 601         if (rc != EOK) {
 602                 ext4_fs_put_block_group_ref(&bg_ref);
 603                 return rc;
 604         }
 605
 606         if (!ext4_balloc_verify_bitmap_csum(sb, bg_ref.block_group, b.data)) {
 607                 ext4_dbg(DEBUG_BALLOC,
 608                         DBG_WARN "Bitmap checksum failed."
 609                         "Group: %" PRIu32"\n",
 610                         bg_ref.index);
 611         }
 612
 613         /* Check if block is free */
 614         *free = ext4_bmap_is_bit_clr(b.data, index_in_group);
 615
 616         /* Allocate block if possible */
 617         if (*free) {
 618                 ext4_bmap_bit_set(b.data, index_in_group);
 619                 ext4_balloc_set_bitmap_csum(sb, bg_ref.block_group, b.data);
 620                 ext4_trans_set_block_dirty(b.buf);
 621         }
 622
 623         /* Release block with bitmap */
 624         rc = ext4_block_set(fs->bdev, &b);
 625         if (rc != EOK) {
 626                 /* Error in saving bitmap */
 627                 ext4_fs_put_block_group_ref(&bg_ref);
 628                 return rc;
 629         }
 630
 631         /* If block is not free, return */
 632         if (!(*free))
 633                 goto terminate;
 634
 635         uint32_t block_size = ext4_sb_get_block_size(sb);
 636
 637         /* Update superblock free blocks count */
 638         uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
 639         sb_free_blocks--;
 640         ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
 641
 642         /* Update inode blocks count */
 643         uint64_t ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
 644         ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
 645         ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
 646         inode_ref->dirty = true;
 647
 648         /* Update block group free blocks count */
 649         uint32_t fb_cnt = ext4_bg_get_free_blocks_count(bg_ref.block_group, sb);
 650         fb_cnt--;
 651         ext4_bg_set_free_blocks_count(bg_ref.block_group, sb, fb_cnt);
 652
 653         bg_ref.dirty = true;
 654
 655 terminate:
 656         return ext4_fs_put_block_group_ref(&bg_ref);
 657 }
 658
 659 /**
 660  * @}
 661  */