lwext4/ext4_fs.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 /** @addtogroup lwext4
  34  * @{
  35  */
  36 /**
  37  * @file  ext4_fs.c
  38  * @brief More complex filesystem functions.
  39  */
  40
  41 #include "ext4_config.h"
  42 #include "ext4_types.h"
  43 #include "ext4_fs.h"
  44 #include "ext4_errno.h"
  45 #include "ext4_blockdev.h"
  46 #include "ext4_super.h"
  47 #include "ext4_debug.h"
  48 #include "ext4_block_group.h"
  49 #include "ext4_balloc.h"
  50 #include "ext4_bitmap.h"
  51 #include "ext4_inode.h"
  52 #include "ext4_ialloc.h"
  53 #include "ext4_extent.h"
  54
  55 #include <string.h>
  56
  57 int ext4_fs_init(struct ext4_fs *fs, struct ext4_blockdev *bdev)
  58 {
  59         int r, i;
  60         uint16_t tmp;
  61         uint32_t bsize;
  62         bool read_only = false;
  63
  64         ext4_assert(fs && bdev);
  65
  66         fs->bdev = bdev;
  67
  68         r = ext4_sb_read(fs->bdev, &fs->sb);
  69         if (r != EOK)
  70                 return r;
  71
  72         if (!ext4_sb_check(&fs->sb))
  73                 return ENOTSUP;
  74
  75         bsize = ext4_sb_get_block_size(&fs->sb);
  76         if (bsize > EXT4_MAX_BLOCK_SIZE)
  77                 return ENXIO;
  78
  79         r = ext4_fs_check_features(fs, &read_only);
  80         if (r != EOK)
  81                 return r;
  82
  83         if (read_only)
  84                 return ENOTSUP;
  85
  86         /* Compute limits for indirect block levels */
  87         uint32_t blocks_id = bsize / sizeof(uint32_t);
  88
  89         fs->inode_block_limits[0] = EXT4_INODE_DIRECT_BLOCK_COUNT;
  90         fs->inode_blocks_per_level[0] = 1;
  91
  92         for (i = 1; i < 4; i++) {
  93                 fs->inode_blocks_per_level[i] =
  94                     fs->inode_blocks_per_level[i - 1] * blocks_id;
  95                 fs->inode_block_limits[i] = fs->inode_block_limits[i - 1] +
  96                                             fs->inode_blocks_per_level[i];
  97         }
  98
  99         /*Validate FS*/
 100         tmp = ext4_get16(&fs->sb, state);
 101         if (tmp & EXT4_SUPERBLOCK_STATE_ERROR_FS) {
 102                 ext4_dprintf(EXT4_DEBUG_FS, "last umount error\n");
 103         }
 104
 105         /* Mark system as mounted */
 106         ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_ERROR_FS);
 107         r = ext4_sb_write(fs->bdev, &fs->sb);
 108         if (r != EOK)
 109                 return r;
 110
 111         /*Update mount count*/
 112         ext4_set16(&fs->sb, mount_count, ext4_get16(&fs->sb, mount_count) + 1);
 113
 114         return r;
 115 }
 116
 117 int ext4_fs_fini(struct ext4_fs *fs)
 118 {
 119         ext4_assert(fs);
 120
 121         /*Set superblock state*/
 122         ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_VALID_FS);
 123
 124         return ext4_sb_write(fs->bdev, &fs->sb);
 125 }
 126
 127 static void ext4_fs_debug_features_incomp(uint32_t features_incompatible)
 128 {
 129
 130         if (features_incompatible & EXT4_FEATURE_INCOMPAT_COMPRESSION) {
 131                 ext4_dprintf(EXT4_DEBUG_FS, "compression\n");
 132         }
 133         if (features_incompatible & EXT4_FEATURE_INCOMPAT_FILETYPE) {
 134                 ext4_dprintf(EXT4_DEBUG_FS, "filetype\n");
 135         }
 136         if (features_incompatible & EXT4_FEATURE_INCOMPAT_RECOVER) {
 137                 ext4_dprintf(EXT4_DEBUG_FS, "recover\n");
 138         }
 139         if (features_incompatible & EXT4_FEATURE_INCOMPAT_JOURNAL_DEV) {
 140                 ext4_dprintf(EXT4_DEBUG_FS, "journal_dev\n");
 141         }
 142         if (features_incompatible & EXT4_FEATURE_INCOMPAT_META_BG) {
 143                 ext4_dprintf(EXT4_DEBUG_FS, "meta_bg\n");
 144         }
 145         if (features_incompatible & EXT4_FEATURE_INCOMPAT_EXTENTS) {
 146                 ext4_dprintf(EXT4_DEBUG_FS, "extents\n");
 147         }
 148         if (features_incompatible & EXT4_FEATURE_INCOMPAT_64BIT) {
 149                 ext4_dprintf(EXT4_DEBUG_FS, "64bit\n");
 150         }
 151         if (features_incompatible & EXT4_FEATURE_INCOMPAT_MMP) {
 152                 ext4_dprintf(EXT4_DEBUG_FS, "mnp\n");
 153         }
 154         if (features_incompatible & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
 155                 ext4_dprintf(EXT4_DEBUG_FS, "flex_bg\n");
 156         }
 157         if (features_incompatible & EXT4_FEATURE_INCOMPAT_EA_INODE) {
 158                 ext4_dprintf(EXT4_DEBUG_FS, "ea_inode\n");
 159         }
 160         if (features_incompatible & EXT4_FEATURE_INCOMPAT_DIRDATA) {
 161                 ext4_dprintf(EXT4_DEBUG_FS, "dirdata\n");
 162         }
 163         if (features_incompatible & EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM) {
 164                 ext4_dprintf(EXT4_DEBUG_FS, "meta_csum\n");
 165         }
 166         if (features_incompatible & EXT4_FEATURE_INCOMPAT_LARGEDIR) {
 167                 ext4_dprintf(EXT4_DEBUG_FS, "largedir\n");
 168         }
 169         if (features_incompatible & EXT4_FEATURE_INCOMPAT_INLINE_DATA) {
 170                 ext4_dprintf(EXT4_DEBUG_FS, "inline_data\n");
 171         }
 172 }
 173 static void ext4_fs_debug_features_comp(uint32_t features_compatible)
 174 {
 175         if (features_compatible & EXT4_FEATURE_COMPAT_DIR_PREALLOC) {
 176                 ext4_dprintf(EXT4_DEBUG_FS, " dir_prealloc\n");
 177         }
 178         if (features_compatible & EXT4_FEATURE_COMPAT_IMAGIC_INODES) {
 179                 ext4_dprintf(EXT4_DEBUG_FS, "imagic_inodes\n");
 180         }
 181         if (features_compatible & EXT4_FEATURE_COMPAT_HAS_JOURNAL) {
 182                 ext4_dprintf(EXT4_DEBUG_FS, "has_journal\n");
 183         }
 184         if (features_compatible & EXT4_FEATURE_COMPAT_EXT_ATTR) {
 185                 ext4_dprintf(EXT4_DEBUG_FS, "ext_attr\n");
 186         }
 187         if (features_compatible & EXT4_FEATURE_COMPAT_RESIZE_INODE) {
 188                 ext4_dprintf(EXT4_DEBUG_FS, "resize_inode\n");
 189         }
 190         if (features_compatible & EXT4_FEATURE_COMPAT_DIR_INDEX) {
 191                 ext4_dprintf(EXT4_DEBUG_FS, "dir_index\n");
 192         }
 193 }
 194
 195 static void ext4_fs_debug_features_ro(uint32_t features_ro)
 196 {
 197         if (features_ro & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER) {
 198                 ext4_dprintf(EXT4_DEBUG_FS, "sparse_super\n");
 199         }
 200         if (features_ro & EXT4_FEATURE_RO_COMPAT_LARGE_FILE) {
 201                 ext4_dprintf(EXT4_DEBUG_FS, "large_file\n");
 202         }
 203         if (features_ro & EXT4_FEATURE_RO_COMPAT_BTREE_DIR) {
 204                 ext4_dprintf(EXT4_DEBUG_FS, "btree_dir\n");
 205         }
 206         if (features_ro & EXT4_FEATURE_RO_COMPAT_HUGE_FILE) {
 207                 ext4_dprintf(EXT4_DEBUG_FS, "huge_file\n");
 208         }
 209         if (features_ro & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
 210                 ext4_dprintf(EXT4_DEBUG_FS, "gtd_csum\n");
 211         }
 212         if (features_ro & EXT4_FEATURE_RO_COMPAT_DIR_NLINK) {
 213                 ext4_dprintf(EXT4_DEBUG_FS, "dir_nlink\n");
 214         }
 215         if (features_ro & EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE) {
 216                 ext4_dprintf(EXT4_DEBUG_FS, "extra_isize\n");
 217         }
 218         if (features_ro & EXT4_FEATURE_RO_COMPAT_QUOTA) {
 219                 ext4_dprintf(EXT4_DEBUG_FS, "quota\n");
 220         }
 221         if (features_ro & EXT4_FEATURE_RO_COMPAT_BIGALLOC) {
 222                 ext4_dprintf(EXT4_DEBUG_FS, "bigalloc\n");
 223         }
 224         if (features_ro & EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) {
 225                 ext4_dprintf(EXT4_DEBUG_FS, "metadata_csum\n");
 226         }
 227 }
 228
 229 int ext4_fs_check_features(struct ext4_fs *fs, bool *read_only)
 230 {
 231         ext4_assert(fs && read_only);
 232         uint32_t v;
 233         if (ext4_get32(&fs->sb, rev_level) == 0) {
 234                 *read_only = false;
 235                 return EOK;
 236         }
 237
 238         ext4_dprintf(EXT4_DEBUG_FS, "\nSB features_incompatible:\n");
 239         ext4_fs_debug_features_incomp(
 240             ext4_get32(&fs->sb, features_incompatible));
 241
 242         ext4_dprintf(EXT4_DEBUG_FS, "\nSB features_compatible:\n");
 243         ext4_fs_debug_features_comp(ext4_get32(&fs->sb, features_compatible));
 244
 245         ext4_dprintf(EXT4_DEBUG_FS, "\nSB features_read_only:\n");
 246         ext4_fs_debug_features_ro(ext4_get32(&fs->sb, features_read_only));
 247
 248         /*Check features_incompatible*/
 249         v = (ext4_get32(&fs->sb, features_incompatible) &
 250              (~CONFIG_FEATURE_INCOMPAT_SUPP));
 251         if (v) {
 252                 ext4_dprintf(EXT4_DEBUG_FS, "SB features_incompatible: fail\n");
 253                 ext4_fs_debug_features_incomp(v);
 254                 return ENOTSUP;
 255         }
 256
 257         /*Check features_read_only*/
 258         v = (ext4_get32(&fs->sb, features_read_only) &
 259              (~CONFIG_FEATURE_RO_COMPAT_SUPP));
 260         if (v) {
 261                 ext4_dprintf(
 262                     EXT4_DEBUG_FS,
 263                     "\nERROR sblock features_read_only . Unsupported:\n");
 264                 ext4_fs_debug_features_incomp(v);
 265
 266                 *read_only = true;
 267                 return EOK;
 268         }
 269         *read_only = false;
 270
 271         return EOK;
 272 }
 273
 274 /**@brief Determine whether the block is inside the group.
 275  * @param baddr   block address
 276  * @param bgid    block group id
 277  * @return Error code
 278  */
 279 static int ext4_block_in_group(struct ext4_sblock *s,
 280                                uint32_t baddr,
 281                                uint32_t bgid)
 282 {
 283         uint32_t actual_bgid;
 284         actual_bgid = ext4_balloc_get_bgid_of_block(s, baddr);
 285         if (actual_bgid == bgid)
 286                 return 1;
 287         return 0;
 288 }
 289
 290 /**@brief   To avoid calling the atomic setbit hundreds or thousands of times, we only
 291  *          need to use it within a single byte (to ensure we get endianness right).
 292  *          We can use memset for the rest of the bitmap as there are no other users.
 293  */
 294 static void ext4_fs_mark_bitmap_end(int start_bit, int end_bit, void *bitmap)
 295 {
 296         int i;
 297
 298         if (start_bit >= end_bit)
 299                 return;
 300
 301         for (i = start_bit; (unsigned)i < ((start_bit + 7) & ~7UL); i++)
 302                 ext4_bmap_bit_set(bitmap, i);
 303
 304         if (i < end_bit)
 305                 memset((char *)bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
 306 }
 307
 308 /**@brief Initialize block bitmap in block group.
 309  * @param bg_ref Reference to block group
 310  * @return Error code
 311  */
 312 static int ext4_fs_init_block_bitmap(struct ext4_block_group_ref *bg_ref)
 313 {
 314         uint32_t i, bit, bit_max;
 315         uint32_t group_blocks;
 316         uint16_t inode_size = ext4_get16(&bg_ref->fs->sb, inode_size);
 317         uint32_t block_size = ext4_sb_get_block_size(&bg_ref->fs->sb);
 318         uint32_t inodes_per_group = ext4_get32(&bg_ref->fs->sb, inodes_per_group);
 319         uint32_t bitmap_block_addr =
 320             ext4_bg_get_block_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
 321         uint32_t bitmap_inode_addr =
 322             ext4_bg_get_inode_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
 323         uint32_t inode_table_addr =
 324             ext4_bg_get_inode_table_first_block(bg_ref->block_group,
 325                                                 &bg_ref->fs->sb);
 326         uint32_t first_group_addr =
 327             ext4_balloc_get_block_of_bgid(&bg_ref->fs->sb, bg_ref->index);
 328
 329         uint32_t dsc_per_block =
 330             ext4_sb_get_block_size(&bg_ref->fs->sb) /
 331             ext4_sb_get_desc_size(&bg_ref->fs->sb);
 332
 333         bool flex_bg =
 334                 ext4_sb_has_feature_incompatible(&bg_ref->fs->sb,
 335                                                  EXT4_FEATURE_INCOMPAT_FLEX_BG);
 336
 337         uint32_t inode_table_bcnt = inodes_per_group * inode_size / block_size;
 338
 339         struct ext4_block block_bitmap;
 340         int rc =
 341             ext4_block_get(bg_ref->fs->bdev, &block_bitmap, bitmap_block_addr);
 342         if (rc != EOK)
 343                 return rc;
 344
 345         memset(block_bitmap.data, 0, block_size);
 346
 347         bit_max = ext4_sb_is_super_in_bg(&bg_ref->fs->sb, bg_ref->index);
 348         if (!ext4_sb_has_feature_incompatible(&bg_ref->fs->sb,
 349                                               EXT4_FEATURE_INCOMPAT_META_BG) ||
 350                         bg_ref->index < ext4_sb_first_meta_bg(&bg_ref->fs->sb) *
 351                         dsc_per_block) {
 352                 if (bit_max) {
 353                         bit_max += ext4_bg_num_gdb(&bg_ref->fs->sb,
 354                                                    bg_ref->index);
 355                         bit_max +=
 356                                 ext4_get16(&bg_ref->fs->sb,
 357                                            s_reserved_gdt_blocks);
 358                 }
 359         } else { /* For META_BG_BLOCK_GROUPS */
 360                 bit_max += ext4_bg_num_gdb(&bg_ref->fs->sb,
 361                                            bg_ref->index);
 362         }
 363         for (bit = 0; bit < bit_max; bit++)
 364                 ext4_bmap_bit_set(block_bitmap.data, bit);
 365
 366         if (bg_ref->index == ext4_block_group_cnt(&bg_ref->fs->sb) - 1) {
 367                 /*
 368                  * Even though mke2fs always initialize first and last group
 369                  * if some other tool enabled the EXT4_BG_BLOCK_UNINIT we need
 370                  * to make sure we calculate the right free blocks
 371                  */
 372                 group_blocks = (ext4_sb_get_blocks_cnt(&bg_ref->fs->sb) -
 373                                 ext4_get32(&bg_ref->fs->sb, first_data_block) -
 374                                 (ext4_get32(&bg_ref->fs->sb, blocks_per_group) *
 375                                  (ext4_block_group_cnt(&bg_ref->fs->sb) - 1)));
 376         } else {
 377                 group_blocks = ext4_get32(&bg_ref->fs->sb, blocks_per_group);
 378         }
 379         if (!flex_bg ||
 380             ext4_block_in_group(&bg_ref->fs->sb,
 381                                 bitmap_block_addr, bg_ref->index))
 382                 ext4_bmap_bit_set(block_bitmap.data,
 383                                   bitmap_block_addr - first_group_addr);
 384
 385         if (!flex_bg ||
 386             ext4_block_in_group(&bg_ref->fs->sb,
 387                                 bitmap_inode_addr, bg_ref->index))
 388                 ext4_bmap_bit_set(block_bitmap.data,
 389                                   bitmap_inode_addr - first_group_addr);
 390
 391         for (i = inode_table_addr;
 392                 i < inode_table_addr + inode_table_bcnt; i++) {
 393                 if (!flex_bg ||
 394                     ext4_block_in_group(&bg_ref->fs->sb,
 395                                         i,
 396                                         bg_ref->index))
 397                         ext4_bmap_bit_set(block_bitmap.data,
 398                                         i - first_group_addr);
 399         }
 400         /*
 401          * Also if the number of blocks within the group is
 402          * less than the blocksize * 8 ( which is the size
 403          * of bitmap ), set rest of the block bitmap to 1
 404          */
 405         ext4_fs_mark_bitmap_end(group_blocks, block_size * 8, block_bitmap.data);
 406         block_bitmap.dirty = true;
 407
 408         /* Save bitmap */
 409         return ext4_block_set(bg_ref->fs->bdev, &block_bitmap);
 410 }
 411
 412 /**@brief Initialize i-node bitmap in block group.
 413  * @param bg_ref Reference to block group
 414  * @return Error code
 415  */
 416 static int ext4_fs_init_inode_bitmap(struct ext4_block_group_ref *bg_ref)
 417 {
 418         /* Load bitmap */
 419         uint32_t bitmap_block_addr =
 420             ext4_bg_get_inode_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
 421
 422         struct ext4_block block_bitmap;
 423         int rc =
 424             ext4_block_get(bg_ref->fs->bdev, &block_bitmap, bitmap_block_addr);
 425         if (rc != EOK)
 426                 return rc;
 427
 428         /* Initialize all bitmap bits to zero */
 429         uint32_t block_size = ext4_sb_get_block_size(&bg_ref->fs->sb);
 430         uint32_t inodes_per_group =
 431             ext4_get32(&bg_ref->fs->sb, inodes_per_group);
 432
 433         memset(block_bitmap.data, 0, (inodes_per_group + 7) / 8);
 434
 435         uint32_t start_bit = inodes_per_group;
 436         uint32_t end_bit = block_size * 8;
 437
 438         uint32_t i;
 439         for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
 440                 ext4_bmap_bit_set(block_bitmap.data, i);
 441
 442         if (i < end_bit)
 443                 memset(block_bitmap.data + (i >> 3), 0xff, (end_bit - i) >> 3);
 444
 445         block_bitmap.dirty = true;
 446
 447         /* Save bitmap */
 448         return ext4_block_set(bg_ref->fs->bdev, &block_bitmap);
 449 }
 450
 451 /**@brief Initialize i-node table in block group.
 452  * @param bg_ref Reference to block group
 453  * @return Error code
 454  */
 455 static int ext4_fs_init_inode_table(struct ext4_block_group_ref *bg_ref)
 456 {
 457         struct ext4_sblock *sb = &bg_ref->fs->sb;
 458
 459         uint32_t inode_size = ext4_get32(sb, inode_size);
 460         uint32_t block_size = ext4_sb_get_block_size(sb);
 461         uint32_t inodes_per_block = block_size / inode_size;
 462         uint32_t inodes_in_group = ext4_inodes_in_group_cnt(sb, bg_ref->index);
 463         uint32_t table_blocks = inodes_in_group / inodes_per_block;
 464         uint32_t fblock;
 465
 466         if (inodes_in_group % inodes_per_block)
 467                 table_blocks++;
 468
 469         /* Compute initialization bounds */
 470         uint32_t first_block =
 471             ext4_bg_get_inode_table_first_block(bg_ref->block_group, sb);
 472
 473         uint32_t last_block = first_block + table_blocks - 1;
 474
 475         /* Initialization of all itable blocks */
 476         for (fblock = first_block; fblock <= last_block; ++fblock) {
 477
 478                 struct ext4_block block;
 479                 int rc = ext4_block_get(bg_ref->fs->bdev, &block, fblock);
 480                 if (rc != EOK)
 481                         return rc;
 482
 483                 memset(block.data, 0, block_size);
 484                 block.dirty = true;
 485
 486                 ext4_block_set(bg_ref->fs->bdev, &block);
 487                 if (rc != EOK)
 488                         return rc;
 489         }
 490
 491         return EOK;
 492 }
 493
 494 static uint64_t ext4_fs_get_descriptor_block(struct ext4_sblock *s,
 495                                              uint32_t bgid,
 496                                              uint32_t dsc_per_block)
 497 {
 498         uint32_t first_meta_bg, dsc_id;
 499
 500         int has_super = 0;
 501
 502         dsc_id = bgid / dsc_per_block;
 503         first_meta_bg = ext4_sb_first_meta_bg(s);
 504
 505         if (!ext4_sb_has_feature_incompatible(s,
 506                                               EXT4_FEATURE_INCOMPAT_META_BG) ||
 507             dsc_id < first_meta_bg)
 508                 return ext4_get32(s, first_data_block) + dsc_id + 1;
 509
 510         if (ext4_sb_is_super_in_bg(s, bgid))
 511                 has_super = 1;
 512
 513         return (has_super + ext4_fs_first_bg_block_no(s, bgid));
 514 }
 515
 516 int ext4_fs_get_block_group_ref(struct ext4_fs *fs, uint32_t bgid,
 517                                 struct ext4_block_group_ref *ref)
 518 {
 519         /* Compute number of descriptors, that fits in one data block */
 520         uint32_t dsc_per_block =
 521             ext4_sb_get_block_size(&fs->sb) / ext4_sb_get_desc_size(&fs->sb);
 522
 523         /* Block group descriptor table starts at the next block after
 524          * superblock */
 525         uint64_t block_id =
 526             ext4_fs_get_descriptor_block(&fs->sb, bgid, dsc_per_block);
 527
 528         uint32_t offset =
 529             (bgid % dsc_per_block) * ext4_sb_get_desc_size(&fs->sb);
 530
 531         int rc = ext4_block_get(fs->bdev, &ref->block, block_id);
 532         if (rc != EOK)
 533                 return rc;
 534
 535         ref->block_group = (void *)(ref->block.data + offset);
 536         ref->fs = fs;
 537         ref->index = bgid;
 538         ref->dirty = false;
 539
 540         if (ext4_bg_has_flag(ref->block_group, EXT4_BLOCK_GROUP_BLOCK_UNINIT)) {
 541                 rc = ext4_fs_init_block_bitmap(ref);
 542                 if (rc != EOK) {
 543                         ext4_block_set(fs->bdev, &ref->block);
 544                         return rc;
 545                 }
 546                 ext4_bg_clear_flag(ref->block_group,
 547                                    EXT4_BLOCK_GROUP_BLOCK_UNINIT);
 548
 549                 ref->dirty = true;
 550         }
 551
 552         if (ext4_bg_has_flag(ref->block_group, EXT4_BLOCK_GROUP_INODE_UNINIT)) {
 553                 rc = ext4_fs_init_inode_bitmap(ref);
 554                 if (rc != EOK) {
 555                         ext4_block_set(ref->fs->bdev, &ref->block);
 556                         return rc;
 557                 }
 558
 559                 ext4_bg_clear_flag(ref->block_group,
 560                                    EXT4_BLOCK_GROUP_INODE_UNINIT);
 561
 562                 if (!ext4_bg_has_flag(ref->block_group,
 563                                       EXT4_BLOCK_GROUP_ITABLE_ZEROED)) {
 564                         rc = ext4_fs_init_inode_table(ref);
 565                         if (rc != EOK) {
 566                                 ext4_block_set(fs->bdev, &ref->block);
 567                                 return rc;
 568                         }
 569
 570                         ext4_bg_set_flag(ref->block_group,
 571                                          EXT4_BLOCK_GROUP_ITABLE_ZEROED);
 572                 }
 573
 574                 ref->dirty = true;
 575         }
 576
 577         return EOK;
 578 }
 579
 580 /**@brief  Compute checksum of block group descriptor.
 581  * @param sb   Superblock
 582  * @param bgid Index of block group in the filesystem
 583  * @param bg   Block group to compute checksum for
 584  * @return Checksum value
 585  */
 586 static uint16_t ext4_fs_bg_checksum(struct ext4_sblock *sb, uint32_t bgid,
 587                                     struct ext4_bgroup *bg)
 588 {
 589         /* If checksum not supported, 0 will be returned */
 590         uint16_t crc = 0;
 591
 592         /* Compute the checksum only if the filesystem supports it */
 593         if (ext4_sb_has_feature_read_only(sb,
 594                                           EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
 595                 uint8_t *base = (uint8_t *)bg;
 596                 uint8_t *checksum = (uint8_t *)&bg->checksum;
 597
 598                 uint32_t offset = (uint32_t)(checksum - base);
 599
 600                 /* Convert block group index to little endian */
 601                 uint32_t le_group = to_le32(bgid);
 602
 603                 /* Initialization */
 604                 crc = ext4_bg_crc16(~0, sb->uuid, sizeof(sb->uuid));
 605
 606                 /* Include index of block group */
 607                 crc =
 608                     ext4_bg_crc16(crc, (uint8_t *)&le_group, sizeof(le_group));
 609
 610                 /* Compute crc from the first part (stop before checksum field)
 611                  */
 612                 crc = ext4_bg_crc16(crc, (uint8_t *)bg, offset);
 613
 614                 /* Skip checksum */
 615                 offset += sizeof(bg->checksum);
 616
 617                 /* Checksum of the rest of block group descriptor */
 618                 if ((ext4_sb_has_feature_incompatible(
 619                         sb, EXT4_FEATURE_INCOMPAT_64BIT)) &&
 620                     (offset < ext4_sb_get_desc_size(sb)))
 621
 622                         crc = ext4_bg_crc16(crc, ((uint8_t *)bg) + offset,
 623                                             ext4_sb_get_desc_size(sb) - offset);
 624         }
 625         return crc;
 626 }
 627
 628 int ext4_fs_put_block_group_ref(struct ext4_block_group_ref *ref)
 629 {
 630         /* Check if reference modified */
 631         if (ref->dirty) {
 632                 /* Compute new checksum of block group */
 633                 uint16_t checksum = ext4_fs_bg_checksum(
 634                     &ref->fs->sb, ref->index, ref->block_group);
 635
 636                 ref->block_group->checksum = to_le16(checksum);
 637
 638                 /* Mark block dirty for writing changes to physical device */
 639                 ref->block.dirty = true;
 640         }
 641
 642         /* Put back block, that contains block group descriptor */
 643         return ext4_block_set(ref->fs->bdev, &ref->block);
 644 }
 645
 646 int ext4_fs_get_inode_ref(struct ext4_fs *fs, uint32_t index,
 647                           struct ext4_inode_ref *ref)
 648 {
 649         /* Compute number of i-nodes, that fits in one data block */
 650         uint32_t inodes_per_group = ext4_get32(&fs->sb, inodes_per_group);
 651
 652         /*
 653          * Inode numbers are 1-based, but it is simpler to work with 0-based
 654          * when computing indices
 655          */
 656         index -= 1;
 657         uint32_t block_group = index / inodes_per_group;
 658         uint32_t offset_in_group = index % inodes_per_group;
 659
 660         /* Load block group, where i-node is located */
 661         struct ext4_block_group_ref bg_ref;
 662
 663         int rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
 664         if (rc != EOK) {
 665                 return rc;
 666         }
 667
 668         /* Load block address, where i-node table is located */
 669         uint32_t inode_table_start =
 670             ext4_bg_get_inode_table_first_block(bg_ref.block_group, &fs->sb);
 671
 672         /* Put back block group reference (not needed more) */
 673         rc = ext4_fs_put_block_group_ref(&bg_ref);
 674         if (rc != EOK) {
 675                 return rc;
 676         }
 677
 678         /* Compute position of i-node in the block group */
 679         uint16_t inode_size = ext4_get16(&fs->sb, inode_size);
 680         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
 681         uint32_t byte_offset_in_group = offset_in_group * inode_size;
 682
 683         /* Compute block address */
 684         uint64_t block_id =
 685             inode_table_start + (byte_offset_in_group / block_size);
 686
 687         rc = ext4_block_get(fs->bdev, &ref->block, block_id);
 688         if (rc != EOK) {
 689                 return rc;
 690         }
 691
 692         /* Compute position of i-node in the data block */
 693         uint32_t offset_in_block = byte_offset_in_group % block_size;
 694         ref->inode = (struct ext4_inode *)(ref->block.data + offset_in_block);
 695
 696         /* We need to store the original value of index in the reference */
 697         ref->index = index + 1;
 698         ref->fs = fs;
 699         ref->dirty = false;
 700
 701         return EOK;
 702 }
 703
 704 int ext4_fs_put_inode_ref(struct ext4_inode_ref *ref)
 705 {
 706         /* Check if reference modified */
 707         if (ref->dirty) {
 708                 /* Mark block dirty for writing changes to physical device */
 709                 ref->block.dirty = true;
 710         }
 711
 712         /* Put back block, that contains i-node */
 713         return ext4_block_set(ref->fs->bdev, &ref->block);
 714 }
 715
 716 void ext4_fs_inode_blocks_init(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref)
 717 {
 718         int i;
 719         struct ext4_inode *inode = inode_ref->inode;
 720
 721         for (i = 0; i < EXT4_INODE_BLOCKS; i++)
 722                 inode->blocks[i] = 0;
 723
 724 #if CONFIG_EXTENT_ENABLE
 725         /* Initialize extents if needed */
 726         if (ext4_sb_has_feature_incompatible(&fs->sb,
 727                                 EXT4_FEATURE_INCOMPAT_EXTENTS)) {
 728                 ext4_inode_set_flag(inode, EXT4_INODE_FLAG_EXTENTS);
 729
 730                 /* Initialize extent root header */
 731                 struct ext4_extent_header *header = ext4_inode_get_extent_header(inode);
 732                 ext4_extent_header_set_depth(header, 0);
 733                 ext4_extent_header_set_entries_count(header, 0);
 734                 ext4_extent_header_set_generation(header, 0);
 735                 ext4_extent_header_set_magic(header, EXT4_EXTENT_MAGIC);
 736
 737                 uint16_t max_entries = (EXT4_INODE_BLOCKS * sizeof(uint32_t) -
 738                                 sizeof(struct ext4_extent_header)) /
 739                         sizeof(struct ext4_extent);
 740
 741                 ext4_extent_header_set_max_entries_count(header, max_entries);
 742         }
 743 #endif
 744 }
 745
 746 static uint32_t ext4_fs_correspond_inode_mode(int filetype)
 747 {
 748         switch (filetype) {
 749         case EXT4_DIRENTRY_DIR:
 750                 return EXT4_INODE_MODE_DIRECTORY;
 751         case EXT4_DIRENTRY_REG_FILE:
 752                 return EXT4_INODE_MODE_FILE;
 753         case EXT4_DIRENTRY_SYMLINK:
 754                 return EXT4_INODE_MODE_SOFTLINK;
 755         default:
 756                 /* FIXME: right now we only support 3 file type. */
 757                 ext4_assert(0);
 758         }
 759         return 0;
 760 }
 761
 762 int ext4_fs_alloc_inode(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
 763                         int filetype)
 764 {
 765         /* Check if newly allocated i-node will be a directory */
 766         bool is_dir;
 767
 768         is_dir = (filetype == EXT4_DIRENTRY_DIR);
 769
 770         /* Allocate inode by allocation algorithm */
 771         uint32_t index;
 772         int rc = ext4_ialloc_alloc_inode(fs, &index, is_dir);
 773         if (rc != EOK)
 774                 return rc;
 775
 776         /* Load i-node from on-disk i-node table */
 777         rc = ext4_fs_get_inode_ref(fs, index, inode_ref);
 778         if (rc != EOK) {
 779                 ext4_ialloc_free_inode(fs, index, is_dir);
 780                 return rc;
 781         }
 782
 783         /* Initialize i-node */
 784         struct ext4_inode *inode = inode_ref->inode;
 785
 786         uint32_t mode;
 787         if (is_dir) {
 788                 /*
 789                  * Default directory permissions to be compatible with other
 790                  * systems
 791                  * 0777 (octal) == rwxrwxrwx
 792                  */
 793
 794                 mode = 0777;
 795                 mode |= EXT4_INODE_MODE_DIRECTORY;
 796         } else {
 797                 /*
 798                  * Default file permissions to be compatible with other systems
 799                  * 0666 (octal) == rw-rw-rw-
 800                  */
 801
 802                 mode = 0666;
 803                 mode |= ext4_fs_correspond_inode_mode(filetype);
 804         }
 805         ext4_inode_set_mode(&fs->sb, inode, mode);
 806
 807         ext4_inode_set_links_count(inode, 0);
 808         ext4_inode_set_uid(inode, 0);
 809         ext4_inode_set_gid(inode, 0);
 810         ext4_inode_set_size(inode, 0);
 811         ext4_inode_set_access_time(inode, 0);
 812         ext4_inode_set_change_inode_time(inode, 0);
 813         ext4_inode_set_modification_time(inode, 0);
 814         ext4_inode_set_deletion_time(inode, 0);
 815         ext4_inode_set_blocks_count(&fs->sb, inode, 0);
 816         ext4_inode_set_flags(inode, 0);
 817         ext4_inode_set_generation(inode, 0);
 818
 819         /* Reset blocks array. For symbolic link inode, just
 820          * fill in blocks with 0 */
 821         if (ext4_inode_is_type(&fs->sb, inode, EXT4_INODE_MODE_SOFTLINK)) {
 822                 for (int i = 0; i < EXT4_INODE_BLOCKS; i++)
 823                         inode->blocks[i] = 0;
 824
 825         } else
 826                 ext4_fs_inode_blocks_init(fs, inode_ref);
 827
 828         inode_ref->dirty = true;
 829
 830         return EOK;
 831 }
 832
 833 int ext4_fs_free_inode(struct ext4_inode_ref *inode_ref)
 834 {
 835         struct ext4_fs *fs = inode_ref->fs;
 836         uint32_t offset;
 837         uint32_t suboff;
 838         int rc;
 839 #if CONFIG_EXTENT_ENABLE
 840         /* For extents must be data block destroyed by other way */
 841         if ((ext4_sb_has_feature_incompatible(&fs->sb,
 842                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
 843             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
 844                 /* Data structures are released during truncate operation... */
 845                 goto finish;
 846         }
 847 #endif
 848         /* Release all indirect (no data) blocks */
 849
 850         /* 1) Single indirect */
 851         uint32_t fblock = ext4_inode_get_indirect_block(inode_ref->inode, 0);
 852         if (fblock != 0) {
 853                 int rc = ext4_balloc_free_block(inode_ref, fblock);
 854                 if (rc != EOK)
 855                         return rc;
 856
 857                 ext4_inode_set_indirect_block(inode_ref->inode, 0, 0);
 858         }
 859
 860         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
 861         uint32_t count = block_size / sizeof(uint32_t);
 862
 863         struct ext4_block block;
 864
 865         /* 2) Double indirect */
 866         fblock = ext4_inode_get_indirect_block(inode_ref->inode, 1);
 867         if (fblock != 0) {
 868                 int rc = ext4_block_get(fs->bdev, &block, fblock);
 869                 if (rc != EOK)
 870                         return rc;
 871
 872                 uint32_t ind_block;
 873                 for (offset = 0; offset < count; ++offset) {
 874                         ind_block = to_le32(((uint32_t *)block.data)[offset]);
 875
 876                         if (ind_block == 0)
 877                                 continue;
 878                         rc = ext4_balloc_free_block(inode_ref, ind_block);
 879                         if (rc != EOK) {
 880                                 ext4_block_set(fs->bdev, &block);
 881                                 return rc;
 882                         }
 883
 884                 }
 885
 886                 ext4_block_set(fs->bdev, &block);
 887                 rc = ext4_balloc_free_block(inode_ref, fblock);
 888                 if (rc != EOK)
 889                         return rc;
 890
 891                 ext4_inode_set_indirect_block(inode_ref->inode, 1, 0);
 892         }
 893
 894         /* 3) Tripple indirect */
 895         struct ext4_block subblock;
 896         fblock = ext4_inode_get_indirect_block(inode_ref->inode, 2);
 897         if (fblock == 0)
 898                 goto finish;
 899         rc = ext4_block_get(fs->bdev, &block, fblock);
 900         if (rc != EOK)
 901                 return rc;
 902
 903         uint32_t ind_block;
 904         for (offset = 0; offset < count; ++offset) {
 905                 ind_block = to_le32(((uint32_t *)block.data)[offset]);
 906
 907                 if (ind_block == 0)
 908                         continue;
 909                 rc = ext4_block_get(fs->bdev, &subblock,
 910                                 ind_block);
 911                 if (rc != EOK) {
 912                         ext4_block_set(fs->bdev, &block);
 913                         return rc;
 914                 }
 915
 916                 uint32_t ind_subblk;
 917                 for (suboff = 0; suboff < count; ++suboff) {
 918                         ind_subblk = to_le32(((uint32_t *)subblock.data)[suboff]);
 919
 920                         if (ind_subblk == 0)
 921                                 continue;
 922                         rc = ext4_balloc_free_block(inode_ref, ind_subblk);
 923                         if (rc != EOK) {
 924                                 ext4_block_set(fs->bdev, &subblock);
 925                                 ext4_block_set(fs->bdev, &block);
 926                                 return rc;
 927                         }
 928
 929                 }
 930
 931                 ext4_block_set(fs->bdev, &subblock);
 932
 933                 rc = ext4_balloc_free_block(inode_ref,
 934                                 ind_block);
 935                 if (rc != EOK) {
 936                         ext4_block_set(fs->bdev, &block);
 937                         return rc;
 938                 }
 939
 940         }
 941
 942         ext4_block_set(fs->bdev, &block);
 943         rc = ext4_balloc_free_block(inode_ref, fblock);
 944         if (rc != EOK)
 945                 return rc;
 946
 947         ext4_inode_set_indirect_block(inode_ref->inode, 2, 0);
 948 finish:
 949         /* Mark inode dirty for writing to the physical device */
 950         inode_ref->dirty = true;
 951
 952         /* Free block with extended attributes if present */
 953         uint32_t xattr_block =
 954             ext4_inode_get_file_acl(inode_ref->inode, &fs->sb);
 955         if (xattr_block) {
 956                 int rc = ext4_balloc_free_block(inode_ref, xattr_block);
 957                 if (rc != EOK)
 958                         return rc;
 959
 960                 ext4_inode_set_file_acl(inode_ref->inode, &fs->sb, 0);
 961         }
 962
 963         /* Free inode by allocator */
 964         if (ext4_inode_is_type(&fs->sb, inode_ref->inode,
 965                                EXT4_INODE_MODE_DIRECTORY))
 966                 rc = ext4_ialloc_free_inode(fs, inode_ref->index, true);
 967         else
 968                 rc = ext4_ialloc_free_inode(fs, inode_ref->index, false);
 969
 970         return rc;
 971 }
 972
 973 int ext4_fs_truncate_inode(struct ext4_inode_ref *inode_ref, uint64_t new_size)
 974 {
 975         struct ext4_sblock *sb = &inode_ref->fs->sb;
 976         uint32_t i;
 977
 978         /* Check flags, if i-node can be truncated */
 979         if (!ext4_inode_can_truncate(sb, inode_ref->inode))
 980                 return EINVAL;
 981
 982         /* If sizes are equal, nothing has to be done. */
 983         uint64_t old_size = ext4_inode_get_size(sb, inode_ref->inode);
 984         if (old_size == new_size)
 985                 return EOK;
 986
 987         /* It's not supported to make the larger file by truncate operation */
 988         if (old_size < new_size)
 989                 return EINVAL;
 990
 991         if (ext4_inode_is_type(sb, inode_ref->inode, EXT4_INODE_MODE_SOFTLINK)
 992                         && old_size < sizeof(inode_ref->inode->blocks)
 993                         && !ext4_inode_get_blocks_count(sb, inode_ref->inode)) {
 994                 char *content = (char *)inode_ref->inode->blocks;
 995                 memset(content + new_size, 0,
 996                         sizeof(inode_ref->inode->blocks) - new_size);
 997                 ext4_inode_set_size(inode_ref->inode, new_size);
 998                 inode_ref->dirty = true;
 999
1000                 return EOK;
1001         }
1002
1003         /* Compute how many blocks will be released */
1004         uint32_t block_size = ext4_sb_get_block_size(sb);
1005         uint32_t new_blocks_count = (new_size + block_size - 1) /
1006                                     block_size;
1007         uint32_t old_blocks_count = (old_size + block_size - 1) /
1008                                     block_size;
1009         uint32_t diff_blocks_count = old_blocks_count - new_blocks_count;
1010 #if CONFIG_EXTENT_ENABLE
1011         if ((ext4_sb_has_feature_incompatible(sb,
1012                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
1013             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1014
1015                 /* Extents require special operation */
1016                 if (diff_blocks_count) {
1017                         int rc = ext4_extent_release_blocks_from(
1018                                         inode_ref,
1019                                         new_blocks_count);
1020                         if (rc != EOK)
1021                                 return rc;
1022
1023                 }
1024         } else
1025 #endif
1026         {
1027                 /* Release data blocks from the end of file */
1028
1029                 /* Starting from 1 because of logical blocks are numbered from 0
1030                  */
1031                 for (i = 0; i < diff_blocks_count; ++i) {
1032                         int rc = ext4_fs_release_inode_block(
1033                             inode_ref, new_blocks_count + i);
1034                         if (rc != EOK)
1035                                 return rc;
1036                 }
1037         }
1038
1039         /* Update i-node */
1040         ext4_inode_set_size(inode_ref->inode, new_size);
1041         inode_ref->dirty = true;
1042
1043         return EOK;
1044 }
1045
1046 int ext4_fs_get_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1047                                        uint64_t iblock, uint32_t *fblock)
1048 {
1049         struct ext4_fs *fs = inode_ref->fs;
1050
1051         /* For empty file is situation simple */
1052         if (ext4_inode_get_size(&fs->sb, inode_ref->inode) == 0) {
1053                 *fblock = 0;
1054                 return EOK;
1055         }
1056
1057         uint32_t current_block;
1058 #if CONFIG_EXTENT_ENABLE
1059         /* Handle i-node using extents */
1060         if ((ext4_sb_has_feature_incompatible(&fs->sb,
1061                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
1062             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1063
1064                 int rc =
1065                     ext4_extent_find_block(inode_ref, iblock, &current_block);
1066                 if (rc != EOK)
1067                         return rc;
1068
1069                 *fblock = current_block;
1070                 return EOK;
1071         }
1072 #endif
1073
1074         struct ext4_inode *inode = inode_ref->inode;
1075
1076         /* Direct block are read directly from array in i-node structure */
1077         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1078                 current_block =
1079                     ext4_inode_get_direct_block(inode, (uint32_t)iblock);
1080                 *fblock = current_block;
1081                 return EOK;
1082         }
1083
1084         /* Determine indirection level of the target block */
1085         unsigned int level = 0;
1086         unsigned int i;
1087         for (i = 1; i < 4; i++) {
1088                 if (iblock < fs->inode_block_limits[i]) {
1089                         level = i;
1090                         break;
1091                 }
1092         }
1093
1094         if (level == 0)
1095                 return EIO;
1096
1097         /* Compute offsets for the topmost level */
1098         uint64_t block_offset_in_level =
1099             iblock - fs->inode_block_limits[level - 1];
1100         current_block = ext4_inode_get_indirect_block(inode, level - 1);
1101         uint32_t offset_in_block =
1102             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1103
1104         /* Sparse file */
1105         if (current_block == 0) {
1106                 *fblock = 0;
1107                 return EOK;
1108         }
1109
1110         struct ext4_block block;
1111
1112         /*
1113          * Navigate through other levels, until we find the block number
1114          * or find null reference meaning we are dealing with sparse file
1115          */
1116         while (level > 0) {
1117                 /* Load indirect block */
1118                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1119                 if (rc != EOK)
1120                         return rc;
1121
1122                 /* Read block address from indirect block */
1123                 current_block =
1124                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1125
1126                 /* Put back indirect block untouched */
1127                 rc = ext4_block_set(fs->bdev, &block);
1128                 if (rc != EOK)
1129                         return rc;
1130
1131                 /* Check for sparse file */
1132                 if (current_block == 0) {
1133                         *fblock = 0;
1134                         return EOK;
1135                 }
1136
1137                 /* Jump to the next level */
1138                 level--;
1139
1140                 /* Termination condition - we have address of data block loaded
1141                  */
1142                 if (level == 0)
1143                         break;
1144
1145                 /* Visit the next level */
1146                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1147                 offset_in_block = block_offset_in_level /
1148                                   fs->inode_blocks_per_level[level - 1];
1149         }
1150
1151         *fblock = current_block;
1152
1153         return EOK;
1154 }
1155
1156 int ext4_fs_set_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1157                                        uint64_t iblock, uint32_t fblock)
1158 {
1159         struct ext4_fs *fs = inode_ref->fs;
1160
1161 #if CONFIG_EXTENT_ENABLE
1162         /* Handle inode using extents */
1163         if ((ext4_sb_has_feature_incompatible(&fs->sb,
1164                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
1165             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1166                 /* Not reachable */
1167                 return ENOTSUP;
1168         }
1169 #endif
1170
1171         /* Handle simple case when we are dealing with direct reference */
1172         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1173                 ext4_inode_set_direct_block(inode_ref->inode, (uint32_t)iblock,
1174                                             fblock);
1175                 inode_ref->dirty = true;
1176
1177                 return EOK;
1178         }
1179
1180         /* Determine the indirection level needed to get the desired block */
1181         unsigned int level = 0;
1182         unsigned int i;
1183         for (i = 1; i < 4; i++) {
1184                 if (iblock < fs->inode_block_limits[i]) {
1185                         level = i;
1186                         break;
1187                 }
1188         }
1189
1190         if (level == 0)
1191                 return EIO;
1192
1193         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
1194
1195         /* Compute offsets for the topmost level */
1196         uint64_t block_offset_in_level =
1197             iblock - fs->inode_block_limits[level - 1];
1198         uint32_t current_block =
1199             ext4_inode_get_indirect_block(inode_ref->inode, level - 1);
1200         uint32_t offset_in_block =
1201             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1202
1203         uint32_t new_block_addr;
1204
1205         struct ext4_block block;
1206         struct ext4_block new_block;
1207
1208         /* Is needed to allocate indirect block on the i-node level */
1209         if (current_block == 0) {
1210                 /* Allocate new indirect block */
1211                 int rc = ext4_balloc_alloc_block(inode_ref, &new_block_addr);
1212                 if (rc != EOK)
1213                         return rc;
1214
1215                 /* Update i-node */
1216                 ext4_inode_set_indirect_block(inode_ref->inode, level - 1,
1217                                               new_block_addr);
1218                 inode_ref->dirty = true;
1219
1220                 /* Load newly allocated block */
1221                 rc = ext4_block_get(fs->bdev, &new_block, new_block_addr);
1222                 if (rc != EOK) {
1223                         ext4_balloc_free_block(inode_ref, new_block_addr);
1224                         return rc;
1225                 }
1226
1227                 /* Initialize new block */
1228                 memset(new_block.data, 0, block_size);
1229                 new_block.dirty = true;
1230
1231                 /* Put back the allocated block */
1232                 rc = ext4_block_set(fs->bdev, &new_block);
1233                 if (rc != EOK)
1234                         return rc;
1235
1236                 current_block = new_block_addr;
1237         }
1238
1239         /*
1240          * Navigate through other levels, until we find the block number
1241          * or find null reference meaning we are dealing with sparse file
1242          */
1243         while (level > 0) {
1244                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1245                 if (rc != EOK)
1246                         return rc;
1247
1248                 current_block =
1249                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1250
1251                 if ((level > 1) && (current_block == 0)) {
1252                         /* Allocate new block */
1253                         rc =
1254                             ext4_balloc_alloc_block(inode_ref, &new_block_addr);
1255                         if (rc != EOK) {
1256                                 ext4_block_set(fs->bdev, &block);
1257                                 return rc;
1258                         }
1259
1260                         /* Load newly allocated block */
1261                         rc = ext4_block_get(fs->bdev, &new_block,
1262                                             new_block_addr);
1263
1264                         if (rc != EOK) {
1265                                 ext4_block_set(fs->bdev, &block);
1266                                 return rc;
1267                         }
1268
1269                         /* Initialize allocated block */
1270                         memset(new_block.data, 0, block_size);
1271                         new_block.dirty = true;
1272
1273                         rc = ext4_block_set(fs->bdev, &new_block);
1274                         if (rc != EOK) {
1275                                 ext4_block_set(fs->bdev, &block);
1276                                 return rc;
1277                         }
1278
1279                         /* Write block address to the parent */
1280                         ((uint32_t *)block.data)[offset_in_block] =
1281                             to_le32(new_block_addr);
1282                         block.dirty = true;
1283                         current_block = new_block_addr;
1284                 }
1285
1286                 /* Will be finished, write the fblock address */
1287                 if (level == 1) {
1288                         ((uint32_t *)block.data)[offset_in_block] =
1289                             to_le32(fblock);
1290                         block.dirty = true;
1291                 }
1292
1293                 rc = ext4_block_set(fs->bdev, &block);
1294                 if (rc != EOK)
1295                         return rc;
1296
1297                 level--;
1298
1299                 /*
1300                  * If we are on the last level, break here as
1301                  * there is no next level to visit
1302                  */
1303                 if (level == 0)
1304                         break;
1305
1306                 /* Visit the next level */
1307                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1308                 offset_in_block = block_offset_in_level /
1309                                   fs->inode_blocks_per_level[level - 1];
1310         }
1311
1312         return EOK;
1313 }
1314
1315 int ext4_fs_release_inode_block(struct ext4_inode_ref *inode_ref,
1316                                 uint32_t iblock)
1317 {
1318         uint32_t fblock;
1319
1320         struct ext4_fs *fs = inode_ref->fs;
1321
1322         /* Extents are handled otherwise = there is not support in this function
1323          */
1324         ext4_assert(!(
1325             ext4_sb_has_feature_incompatible(&fs->sb,
1326                                              EXT4_FEATURE_INCOMPAT_EXTENTS) &&
1327             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))));
1328
1329         struct ext4_inode *inode = inode_ref->inode;
1330
1331         /* Handle simple case when we are dealing with direct reference */
1332         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1333                 fblock = ext4_inode_get_direct_block(inode, iblock);
1334
1335                 /* Sparse file */
1336                 if (fblock == 0)
1337                         return EOK;
1338
1339                 ext4_inode_set_direct_block(inode, iblock, 0);
1340                 return ext4_balloc_free_block(inode_ref, fblock);
1341         }
1342
1343         /* Determine the indirection level needed to get the desired block */
1344         unsigned int level = 0;
1345         unsigned int i;
1346         for (i = 1; i < 4; i++) {
1347                 if (iblock < fs->inode_block_limits[i]) {
1348                         level = i;
1349                         break;
1350                 }
1351         }
1352
1353         if (level == 0)
1354                 return EIO;
1355
1356         /* Compute offsets for the topmost level */
1357         uint64_t block_offset_in_level =
1358             iblock - fs->inode_block_limits[level - 1];
1359         uint32_t current_block =
1360             ext4_inode_get_indirect_block(inode, level - 1);
1361         uint32_t offset_in_block =
1362             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1363
1364         /*
1365          * Navigate through other levels, until we find the block number
1366          * or find null reference meaning we are dealing with sparse file
1367          */
1368         struct ext4_block block;
1369
1370         while (level > 0) {
1371
1372                 /* Sparse check */
1373                 if (current_block == 0)
1374                         return EOK;
1375
1376                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1377                 if (rc != EOK)
1378                         return rc;
1379
1380                 current_block =
1381                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1382
1383                 /* Set zero if physical data block address found */
1384                 if (level == 1) {
1385                         ((uint32_t *)block.data)[offset_in_block] = to_le32(0);
1386                         block.dirty = true;
1387                 }
1388
1389                 rc = ext4_block_set(fs->bdev, &block);
1390                 if (rc != EOK)
1391                         return rc;
1392
1393                 level--;
1394
1395                 /*
1396                  * If we are on the last level, break here as
1397                  * there is no next level to visit
1398                  */
1399                 if (level == 0)
1400                         break;
1401
1402                 /* Visit the next level */
1403                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1404                 offset_in_block = block_offset_in_level /
1405                                   fs->inode_blocks_per_level[level - 1];
1406         }
1407
1408         fblock = current_block;
1409         if (fblock == 0)
1410                 return EOK;
1411
1412         /* Physical block is not referenced, it can be released */
1413         return ext4_balloc_free_block(inode_ref, fblock);
1414 }
1415
1416 int ext4_fs_append_inode_block(struct ext4_inode_ref *inode_ref,
1417                                uint32_t *fblock, uint32_t *iblock)
1418 {
1419 #if CONFIG_EXTENT_ENABLE
1420         /* Handle extents separately */
1421         if ((ext4_sb_has_feature_incompatible(&inode_ref->fs->sb,
1422                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
1423             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1424                 return ext4_extent_append_block(inode_ref, iblock, fblock,
1425                                                 true);
1426         }
1427 #endif
1428         struct ext4_sblock *sb = &inode_ref->fs->sb;
1429
1430         /* Compute next block index and allocate data block */
1431         uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
1432         uint32_t block_size = ext4_sb_get_block_size(sb);
1433
1434         /* Align size i-node size */
1435         if ((inode_size % block_size) != 0)
1436                 inode_size += block_size - (inode_size % block_size);
1437
1438         /* Logical blocks are numbered from 0 */
1439         uint32_t new_block_idx = inode_size / block_size;
1440
1441         /* Allocate new physical block */
1442         uint32_t phys_block;
1443         int rc = ext4_balloc_alloc_block(inode_ref, &phys_block);
1444         if (rc != EOK)
1445                 return rc;
1446
1447         /* Add physical block address to the i-node */
1448         rc = ext4_fs_set_inode_data_block_index(inode_ref, new_block_idx,
1449                                                 phys_block);
1450         if (rc != EOK) {
1451                 ext4_balloc_free_block(inode_ref, phys_block);
1452                 return rc;
1453         }
1454
1455         /* Update i-node */
1456         ext4_inode_set_size(inode_ref->inode, inode_size + block_size);
1457         inode_ref->dirty = true;
1458
1459         *fblock = phys_block;
1460         *iblock = new_block_idx;
1461
1462         return EOK;
1463 }
1464
1465 void ext4_fs_inode_links_count_inc(struct ext4_inode_ref *inode_ref)
1466 {
1467         uint16_t link;
1468
1469         link = ext4_inode_get_links_count(inode_ref->inode);
1470         link++;
1471         ext4_inode_set_links_count(inode_ref->inode, link);
1472
1473         bool is_dx =
1474             ext4_sb_has_feature_compatible(&inode_ref->fs->sb,
1475                                            EXT4_FEATURE_COMPAT_DIR_INDEX) &&
1476             ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_INDEX);
1477
1478         if (is_dx && link > 1) {
1479                 if (link >= EXT4_LINK_MAX || link == 2) {
1480                         ext4_inode_set_links_count(inode_ref->inode, 1);
1481
1482                         uint32_t v =
1483                             ext4_get32(&inode_ref->fs->sb, features_read_only);
1484                         v |= EXT4_FEATURE_RO_COMPAT_DIR_NLINK;
1485                         ext4_set32(&inode_ref->fs->sb, features_read_only, v);
1486                 }
1487         }
1488 }
1489
1490 void ext4_fs_inode_links_count_dec(struct ext4_inode_ref *inode_ref)
1491 {
1492         uint16_t links = ext4_inode_get_links_count(inode_ref->inode);
1493         if (!ext4_inode_is_type(&inode_ref->fs->sb, inode_ref->inode,
1494                                 EXT4_INODE_MODE_DIRECTORY)) {
1495                 if (links > 0)
1496                         ext4_inode_set_links_count(inode_ref->inode, links - 1);
1497                 return;
1498         }
1499
1500         if (links > 2)
1501                 ext4_inode_set_links_count(inode_ref->inode, links - 1);
1502 }
1503
1504 /**
1505  * @}
1506  */