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_crc32c.h"
  48 #include "ext4_debug.h"
  49 #include "ext4_block_group.h"
  50 #include "ext4_balloc.h"
  51 #include "ext4_bitmap.h"
  52 #include "ext4_inode.h"
  53 #include "ext4_ialloc.h"
  54 #include "ext4_extent.h"
  55
  56 #include <string.h>
  57
  58 int ext4_fs_init(struct ext4_fs *fs, struct ext4_blockdev *bdev)
  59 {
  60         int r, i;
  61         uint16_t tmp;
  62         uint32_t bsize;
  63         bool read_only = false;
  64
  65         ext4_assert(fs && bdev);
  66
  67         fs->bdev = bdev;
  68
  69         r = ext4_sb_read(fs->bdev, &fs->sb);
  70         if (r != EOK)
  71                 return r;
  72
  73         if (!ext4_sb_check(&fs->sb))
  74                 return ENOTSUP;
  75
  76         bsize = ext4_sb_get_block_size(&fs->sb);
  77         if (bsize > EXT4_MAX_BLOCK_SIZE)
  78                 return ENXIO;
  79
  80         r = ext4_fs_check_features(fs, &read_only);
  81         if (r != EOK)
  82                 return r;
  83
  84         if (read_only)
  85                 return ENOTSUP;
  86
  87         /* Compute limits for indirect block levels */
  88         uint32_t blocks_id = bsize / sizeof(uint32_t);
  89
  90         fs->inode_block_limits[0] = EXT4_INODE_DIRECT_BLOCK_COUNT;
  91         fs->inode_blocks_per_level[0] = 1;
  92
  93         for (i = 1; i < 4; i++) {
  94                 fs->inode_blocks_per_level[i] =
  95                     fs->inode_blocks_per_level[i - 1] * blocks_id;
  96                 fs->inode_block_limits[i] = fs->inode_block_limits[i - 1] +
  97                                             fs->inode_blocks_per_level[i];
  98         }
  99
 100         /*Validate FS*/
 101         tmp = ext4_get16(&fs->sb, state);
 102         if (tmp & EXT4_SUPERBLOCK_STATE_ERROR_FS)
 103                 ext4_dbg(DEBUG_FS, DBG_WARN
 104                                 "last umount error: superblock fs_error flag\n");
 105
 106
 107         /* Mark system as mounted */
 108         ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_ERROR_FS);
 109         r = ext4_sb_write(fs->bdev, &fs->sb);
 110         if (r != EOK)
 111                 return r;
 112
 113         /*Update mount count*/
 114         ext4_set16(&fs->sb, mount_count, ext4_get16(&fs->sb, mount_count) + 1);
 115
 116         return r;
 117 }
 118
 119 int ext4_fs_fini(struct ext4_fs *fs)
 120 {
 121         ext4_assert(fs);
 122
 123         /*Set superblock state*/
 124         ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_VALID_FS);
 125
 126         return ext4_sb_write(fs->bdev, &fs->sb);
 127 }
 128
 129 static void ext4_fs_debug_features_inc(uint32_t features_incompatible)
 130 {
 131         if (features_incompatible & EXT4_FINCOM_COMPRESSION)
 132                 ext4_dbg(DEBUG_FS, DBG_NONE "compression\n");
 133         if (features_incompatible & EXT4_FINCOM_FILETYPE)
 134                 ext4_dbg(DEBUG_FS, DBG_NONE "filetype\n");
 135         if (features_incompatible & EXT4_FINCOM_RECOVER)
 136                 ext4_dbg(DEBUG_FS, DBG_NONE "recover\n");
 137         if (features_incompatible & EXT4_FINCOM_JOURNAL_DEV)
 138                 ext4_dbg(DEBUG_FS, DBG_NONE "journal_dev\n");
 139         if (features_incompatible & EXT4_FINCOM_META_BG)
 140                 ext4_dbg(DEBUG_FS, DBG_NONE "meta_bg\n");
 141         if (features_incompatible & EXT4_FINCOM_EXTENTS)
 142                 ext4_dbg(DEBUG_FS, DBG_NONE "extents\n");
 143         if (features_incompatible & EXT4_FINCOM_64BIT)
 144                 ext4_dbg(DEBUG_FS, DBG_NONE "64bit\n");
 145         if (features_incompatible & EXT4_FINCOM_MMP)
 146                 ext4_dbg(DEBUG_FS, DBG_NONE "mnp\n");
 147         if (features_incompatible & EXT4_FINCOM_FLEX_BG)
 148                 ext4_dbg(DEBUG_FS, DBG_NONE "flex_bg\n");
 149         if (features_incompatible & EXT4_FINCOM_EA_INODE)
 150                 ext4_dbg(DEBUG_FS, DBG_NONE "ea_inode\n");
 151         if (features_incompatible & EXT4_FINCOM_DIRDATA)
 152                 ext4_dbg(DEBUG_FS, DBG_NONE "dirdata\n");
 153         if (features_incompatible & EXT4_FINCOM_BG_USE_META_CSUM)
 154                 ext4_dbg(DEBUG_FS, DBG_NONE "meta_csum\n");
 155         if (features_incompatible & EXT4_FINCOM_LARGEDIR)
 156                 ext4_dbg(DEBUG_FS, DBG_NONE "largedir\n");
 157         if (features_incompatible & EXT4_FINCOM_INLINE_DATA)
 158                 ext4_dbg(DEBUG_FS, DBG_NONE "inline_data\n");
 159 }
 160 static void ext4_fs_debug_features_comp(uint32_t features_compatible)
 161 {
 162         if (features_compatible & EXT4_FCOM_DIR_PREALLOC)
 163                 ext4_dbg(DEBUG_FS, DBG_NONE "dir_prealloc\n");
 164         if (features_compatible & EXT4_FCOM_IMAGIC_INODES)
 165                 ext4_dbg(DEBUG_FS, DBG_NONE "imagic_inodes\n");
 166         if (features_compatible & EXT4_FCOM_HAS_JOURNAL)
 167                 ext4_dbg(DEBUG_FS, DBG_NONE "has_journal\n");
 168         if (features_compatible & EXT4_FCOM_EXT_ATTR)
 169                 ext4_dbg(DEBUG_FS, DBG_NONE "ext_attr\n");
 170         if (features_compatible & EXT4_FCOM_RESIZE_INODE)
 171                 ext4_dbg(DEBUG_FS, DBG_NONE "resize_inode\n");
 172         if (features_compatible & EXT4_FCOM_DIR_INDEX)
 173                 ext4_dbg(DEBUG_FS, DBG_NONE "dir_index\n");
 174 }
 175
 176 static void ext4_fs_debug_features_ro(uint32_t features_ro)
 177 {
 178         if (features_ro & EXT4_FRO_COM_SPARSE_SUPER)
 179                 ext4_dbg(DEBUG_FS, DBG_NONE "sparse_super\n");
 180         if (features_ro & EXT4_FRO_COM_LARGE_FILE)
 181                 ext4_dbg(DEBUG_FS, DBG_NONE "large_file\n");
 182         if (features_ro & EXT4_FRO_COM_BTREE_DIR)
 183                 ext4_dbg(DEBUG_FS, DBG_NONE "btree_dir\n");
 184         if (features_ro & EXT4_FRO_COM_HUGE_FILE)
 185                 ext4_dbg(DEBUG_FS, DBG_NONE "huge_file\n");
 186         if (features_ro & EXT4_FRO_COM_GDT_CSUM)
 187                 ext4_dbg(DEBUG_FS, DBG_NONE "gtd_csum\n");
 188         if (features_ro & EXT4_FRO_COM_DIR_NLINK)
 189                 ext4_dbg(DEBUG_FS, DBG_NONE "dir_nlink\n");
 190         if (features_ro & EXT4_FRO_COM_EXTRA_ISIZE)
 191                 ext4_dbg(DEBUG_FS, DBG_NONE "extra_isize\n");
 192         if (features_ro & EXT4_FRO_COM_QUOTA)
 193                 ext4_dbg(DEBUG_FS, DBG_NONE "quota\n");
 194         if (features_ro & EXT4_FRO_COM_BIGALLOC)
 195                 ext4_dbg(DEBUG_FS, DBG_NONE "bigalloc\n");
 196         if (features_ro & EXT4_FRO_COM_METADATA_CSUM)
 197                 ext4_dbg(DEBUG_FS, DBG_NONE "metadata_csum\n");
 198 }
 199
 200 int ext4_fs_check_features(struct ext4_fs *fs, bool *read_only)
 201 {
 202         ext4_assert(fs && read_only);
 203         uint32_t v;
 204         if (ext4_get32(&fs->sb, rev_level) == 0) {
 205                 *read_only = false;
 206                 return EOK;
 207         }
 208
 209         ext4_dbg(DEBUG_FS, DBG_INFO "sblock features_incompatible:\n");
 210         ext4_fs_debug_features_inc(ext4_get32(&fs->sb, features_incompatible));
 211
 212         ext4_dbg(DEBUG_FS, DBG_INFO "sblock features_compatible:\n");
 213         ext4_fs_debug_features_comp(ext4_get32(&fs->sb, features_compatible));
 214
 215         ext4_dbg(DEBUG_FS, DBG_INFO "sblock features_read_only:\n");
 216         ext4_fs_debug_features_ro(ext4_get32(&fs->sb, features_read_only));
 217
 218         /*Check features_incompatible*/
 219         v = (ext4_get32(&fs->sb, features_incompatible) &
 220              (~CONFIG_SUPPORTED_FINCOM));
 221         if (v) {
 222                 ext4_dbg(DEBUG_FS, DBG_ERROR
 223                                 "sblock has unsupported features incompatible:\n");
 224                 ext4_fs_debug_features_inc(v);
 225                 return ENOTSUP;
 226         }
 227
 228         /*Check features_read_only*/
 229         v = (ext4_get32(&fs->sb, features_read_only) &
 230              (~CONFIG_SUPPORTED_FRO_COM));
 231         if (v) {
 232                 ext4_dbg(DEBUG_FS, DBG_WARN
 233                                 "sblock has unsupported features read only:\n");
 234                 ext4_fs_debug_features_ro(v);
 235                 *read_only = true;
 236                 return EOK;
 237         }
 238         *read_only = false;
 239
 240         return EOK;
 241 }
 242
 243 /**@brief Determine whether the block is inside the group.
 244  * @param baddr   block address
 245  * @param bgid    block group id
 246  * @return Error code
 247  */
 248 static int ext4_block_in_group(struct ext4_sblock *s,
 249                                ext4_fsblk_t baddr,
 250                                uint32_t bgid)
 251 {
 252         uint32_t actual_bgid;
 253         actual_bgid = ext4_balloc_get_bgid_of_block(s, baddr);
 254         if (actual_bgid == bgid)
 255                 return 1;
 256         return 0;
 257 }
 258
 259 /**@brief   To avoid calling the atomic setbit hundreds or thousands of times, we only
 260  *          need to use it within a single byte (to ensure we get endianness right).
 261  *          We can use memset for the rest of the bitmap as there are no other users.
 262  */
 263 static void ext4_fs_mark_bitmap_end(int start_bit, int end_bit, void *bitmap)
 264 {
 265         int i;
 266
 267         if (start_bit >= end_bit)
 268                 return;
 269
 270         for (i = start_bit; (unsigned)i < ((start_bit + 7) & ~7UL); i++)
 271                 ext4_bmap_bit_set(bitmap, i);
 272
 273         if (i < end_bit)
 274                 memset((char *)bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
 275 }
 276
 277 /**@brief Initialize block bitmap in block group.
 278  * @param bg_ref Reference to block group
 279  * @return Error code
 280  */
 281 static int ext4_fs_init_block_bitmap(struct ext4_block_group_ref *bg_ref)
 282 {
 283         uint32_t i, bit, bit_max;
 284         uint32_t group_blocks;
 285         uint16_t inode_size = ext4_get16(&bg_ref->fs->sb, inode_size);
 286         uint32_t block_size = ext4_sb_get_block_size(&bg_ref->fs->sb);
 287         uint32_t inodes_per_group = ext4_get32(&bg_ref->fs->sb, inodes_per_group);
 288         ext4_fsblk_t bitmap_block_addr =
 289             ext4_bg_get_block_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
 290         ext4_fsblk_t bitmap_inode_addr =
 291             ext4_bg_get_inode_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
 292         ext4_fsblk_t inode_table_addr =
 293             ext4_bg_get_inode_table_first_block(bg_ref->block_group,
 294                                                 &bg_ref->fs->sb);
 295         ext4_fsblk_t first_group_addr =
 296             ext4_balloc_get_block_of_bgid(&bg_ref->fs->sb, bg_ref->index);
 297
 298         uint32_t dsc_per_block =
 299             ext4_sb_get_block_size(&bg_ref->fs->sb) /
 300             ext4_sb_get_desc_size(&bg_ref->fs->sb);
 301
 302         bool flex_bg =
 303                 ext4_sb_feature_incom(&bg_ref->fs->sb, EXT4_FINCOM_FLEX_BG);
 304
 305         uint32_t inode_table_bcnt = inodes_per_group * inode_size / block_size;
 306
 307         struct ext4_block block_bitmap;
 308         int rc =
 309             ext4_block_get_noread(bg_ref->fs->bdev, &block_bitmap, bitmap_block_addr);
 310         if (rc != EOK)
 311                 return rc;
 312
 313         memset(block_bitmap.data, 0, block_size);
 314
 315         bit_max = ext4_sb_is_super_in_bg(&bg_ref->fs->sb, bg_ref->index);
 316         if (!ext4_sb_feature_incom(&bg_ref->fs->sb, EXT4_FINCOM_META_BG) ||
 317                         bg_ref->index < ext4_sb_first_meta_bg(&bg_ref->fs->sb) *
 318                         dsc_per_block) {
 319                 if (bit_max) {
 320                         bit_max += ext4_bg_num_gdb(&bg_ref->fs->sb,
 321                                                    bg_ref->index);
 322                         bit_max +=
 323                                 ext4_get16(&bg_ref->fs->sb,
 324                                            s_reserved_gdt_blocks);
 325                 }
 326         } else { /* For META_BG_BLOCK_GROUPS */
 327                 bit_max += ext4_bg_num_gdb(&bg_ref->fs->sb,
 328                                            bg_ref->index);
 329         }
 330         for (bit = 0; bit < bit_max; bit++)
 331                 ext4_bmap_bit_set(block_bitmap.data, bit);
 332
 333         if (bg_ref->index == ext4_block_group_cnt(&bg_ref->fs->sb) - 1) {
 334                 /*
 335                  * Even though mke2fs always initialize first and last group
 336                  * if some other tool enabled the EXT4_BG_BLOCK_UNINIT we need
 337                  * to make sure we calculate the right free blocks
 338                  */
 339                 group_blocks = (ext4_sb_get_blocks_cnt(&bg_ref->fs->sb) -
 340                                 ext4_get32(&bg_ref->fs->sb, first_data_block) -
 341                                 (ext4_get32(&bg_ref->fs->sb, blocks_per_group) *
 342                                  (ext4_block_group_cnt(&bg_ref->fs->sb) - 1)));
 343         } else {
 344                 group_blocks = ext4_get32(&bg_ref->fs->sb, blocks_per_group);
 345         }
 346         if (!flex_bg ||
 347             ext4_block_in_group(&bg_ref->fs->sb,
 348                                 bitmap_block_addr, bg_ref->index))
 349                 ext4_bmap_bit_set(block_bitmap.data,
 350                                   bitmap_block_addr - first_group_addr);
 351
 352         if (!flex_bg ||
 353             ext4_block_in_group(&bg_ref->fs->sb,
 354                                 bitmap_inode_addr, bg_ref->index))
 355                 ext4_bmap_bit_set(block_bitmap.data,
 356                                   bitmap_inode_addr - first_group_addr);
 357
 358         for (i = inode_table_addr;
 359                 i < inode_table_addr + inode_table_bcnt; i++) {
 360                 if (!flex_bg ||
 361                     ext4_block_in_group(&bg_ref->fs->sb,
 362                                         i,
 363                                         bg_ref->index))
 364                         ext4_bmap_bit_set(block_bitmap.data,
 365                                         i - first_group_addr);
 366         }
 367         /*
 368          * Also if the number of blocks within the group is
 369          * less than the blocksize * 8 ( which is the size
 370          * of bitmap ), set rest of the block bitmap to 1
 371          */
 372         ext4_fs_mark_bitmap_end(group_blocks, block_size * 8, block_bitmap.data);
 373         block_bitmap.dirty = true;
 374
 375         ext4_balloc_set_bitmap_csum(&bg_ref->fs->sb,
 376                                     bg_ref->block_group,
 377                                     block_bitmap.data);
 378         bg_ref->dirty = true;
 379
 380         /* Save bitmap */
 381         return ext4_block_set(bg_ref->fs->bdev, &block_bitmap);
 382 }
 383
 384 /**@brief Initialize i-node bitmap in block group.
 385  * @param bg_ref Reference to block group
 386  * @return Error code
 387  */
 388 static int ext4_fs_init_inode_bitmap(struct ext4_block_group_ref *bg_ref)
 389 {
 390         /* Load bitmap */
 391         ext4_fsblk_t bitmap_block_addr =
 392             ext4_bg_get_inode_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
 393
 394         struct ext4_block block_bitmap;
 395         int rc =
 396             ext4_block_get_noread(bg_ref->fs->bdev,
 397                                   &block_bitmap, bitmap_block_addr);
 398         if (rc != EOK)
 399                 return rc;
 400
 401         /* Initialize all bitmap bits to zero */
 402         uint32_t block_size = ext4_sb_get_block_size(&bg_ref->fs->sb);
 403         uint32_t inodes_per_group =
 404             ext4_get32(&bg_ref->fs->sb, inodes_per_group);
 405
 406         memset(block_bitmap.data, 0, (inodes_per_group + 7) / 8);
 407
 408         uint32_t start_bit = inodes_per_group;
 409         uint32_t end_bit = block_size * 8;
 410
 411         uint32_t i;
 412         for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
 413                 ext4_bmap_bit_set(block_bitmap.data, i);
 414
 415         if (i < end_bit)
 416                 memset(block_bitmap.data + (i >> 3), 0xff, (end_bit - i) >> 3);
 417
 418         block_bitmap.dirty = true;
 419
 420         ext4_ialloc_set_bitmap_csum(&bg_ref->fs->sb,
 421                                     bg_ref->block_group,
 422                                     block_bitmap.data);
 423         bg_ref->dirty = true;
 424
 425         /* Save bitmap */
 426         return ext4_block_set(bg_ref->fs->bdev, &block_bitmap);
 427 }
 428
 429 /**@brief Initialize i-node table in block group.
 430  * @param bg_ref Reference to block group
 431  * @return Error code
 432  */
 433 static int ext4_fs_init_inode_table(struct ext4_block_group_ref *bg_ref)
 434 {
 435         struct ext4_sblock *sb = &bg_ref->fs->sb;
 436
 437         uint32_t inode_size = ext4_get32(sb, inode_size);
 438         uint32_t block_size = ext4_sb_get_block_size(sb);
 439         uint32_t inodes_per_block = block_size / inode_size;
 440         uint32_t inodes_in_group = ext4_inodes_in_group_cnt(sb, bg_ref->index);
 441         uint32_t table_blocks = inodes_in_group / inodes_per_block;
 442         ext4_fsblk_t fblock;
 443
 444         if (inodes_in_group % inodes_per_block)
 445                 table_blocks++;
 446
 447         /* Compute initialization bounds */
 448         ext4_fsblk_t first_block =
 449             ext4_bg_get_inode_table_first_block(bg_ref->block_group, sb);
 450
 451         ext4_fsblk_t last_block = first_block + table_blocks - 1;
 452
 453         /* Initialization of all itable blocks */
 454         for (fblock = first_block; fblock <= last_block; ++fblock) {
 455
 456                 struct ext4_block block;
 457                 int rc = ext4_block_get_noread(bg_ref->fs->bdev, &block, fblock);
 458                 if (rc != EOK)
 459                         return rc;
 460
 461                 memset(block.data, 0, block_size);
 462                 block.dirty = true;
 463
 464                 ext4_block_set(bg_ref->fs->bdev, &block);
 465                 if (rc != EOK)
 466                         return rc;
 467         }
 468
 469         return EOK;
 470 }
 471
 472 static ext4_fsblk_t ext4_fs_get_descriptor_block(struct ext4_sblock *s,
 473                                              uint32_t bgid,
 474                                              uint32_t dsc_per_block)
 475 {
 476         uint32_t first_meta_bg, dsc_id;
 477
 478         int has_super = 0;
 479
 480         dsc_id = bgid / dsc_per_block;
 481         first_meta_bg = ext4_sb_first_meta_bg(s);
 482
 483         if (!ext4_sb_feature_incom(s, EXT4_FINCOM_META_BG) ||
 484             dsc_id < first_meta_bg)
 485                 return ext4_get32(s, first_data_block) + dsc_id + 1;
 486
 487         if (ext4_sb_is_super_in_bg(s, bgid))
 488                 has_super = 1;
 489
 490         return (has_super + ext4_fs_first_bg_block_no(s, bgid));
 491 }
 492
 493 /**@brief  Compute checksum of block group descriptor.
 494  * @param sb   Superblock
 495  * @param bgid Index of block group in the filesystem
 496  * @param bg   Block group to compute checksum for
 497  * @return Checksum value
 498  */
 499 static uint16_t ext4_fs_bg_checksum(struct ext4_sblock *sb, uint32_t bgid,
 500                                     struct ext4_bgroup *bg)
 501 {
 502         /* If checksum not supported, 0 will be returned */
 503         uint16_t crc = 0;
 504 #if CONFIG_META_CSUM_ENABLE
 505         /* Compute the checksum only if the filesystem supports it */
 506         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
 507                 /* Use metadata_csum algorithm instead */
 508                 uint32_t le32_bgid = to_le32(bgid);
 509                 uint32_t orig_checksum, checksum;
 510
 511                 /* Preparation: temporarily set bg checksum to 0 */
 512                 orig_checksum = bg->checksum;
 513                 bg->checksum = 0;
 514
 515                 /* First calculate crc32 checksum against fs uuid */
 516                 checksum = ext4_crc32c(EXT4_CRC32_INIT, sb->uuid,
 517                                 sizeof(sb->uuid));
 518                 /* Then calculate crc32 checksum against bgid */
 519                 checksum = ext4_crc32c(checksum, &le32_bgid,
 520                                      sizeof(bgid));
 521                 /* Finally calculate crc32 checksum against block_group_desc */
 522                 checksum = ext4_crc32c(checksum, bg,
 523                                      ext4_sb_get_desc_size(sb));
 524                 bg->checksum = orig_checksum;
 525
 526                 crc = checksum & 0xFFFF;
 527                 return crc;
 528         }
 529 #endif
 530         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_GDT_CSUM)) {
 531                 uint8_t *base = (uint8_t *)bg;
 532                 uint8_t *checksum = (uint8_t *)&bg->checksum;
 533
 534                 uint32_t offset = (uint32_t)(checksum - base);
 535
 536                 /* Convert block group index to little endian */
 537                 uint32_t le_group = to_le32(bgid);
 538
 539                 /* Initialization */
 540                 crc = ext4_bg_crc16(~0, sb->uuid, sizeof(sb->uuid));
 541
 542                 /* Include index of block group */
 543                 crc =
 544                     ext4_bg_crc16(crc, (uint8_t *)&le_group, sizeof(le_group));
 545
 546                 /* Compute crc from the first part (stop before checksum field)
 547                  */
 548                 crc = ext4_bg_crc16(crc, (uint8_t *)bg, offset);
 549
 550                 /* Skip checksum */
 551                 offset += sizeof(bg->checksum);
 552
 553                 /* Checksum of the rest of block group descriptor */
 554                 if ((ext4_sb_feature_incom(sb, EXT4_FINCOM_64BIT)) &&
 555                     (offset < ext4_sb_get_desc_size(sb)))
 556
 557                         crc = ext4_bg_crc16(crc, ((uint8_t *)bg) + offset,
 558                                             ext4_sb_get_desc_size(sb) - offset);
 559         }
 560         return crc;
 561 }
 562
 563 #if CONFIG_META_CSUM_ENABLE
 564 static bool ext4_fs_verify_bg_csum(struct ext4_sblock *sb,
 565                                    uint32_t bgid,
 566                                    struct ext4_bgroup *bg)
 567 {
 568         if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 569                 return true;
 570
 571         return ext4_fs_bg_checksum(sb,
 572                                    bgid,
 573                                    bg) ==
 574                 to_le16(bg->checksum);
 575 }
 576 #else
 577 #define ext4_fs_verify_bg_csum(...) true
 578 #endif
 579
 580 int ext4_fs_get_block_group_ref(struct ext4_fs *fs, uint32_t bgid,
 581                                 struct ext4_block_group_ref *ref)
 582 {
 583         /* Compute number of descriptors, that fits in one data block */
 584         uint32_t dsc_per_block =
 585             ext4_sb_get_block_size(&fs->sb) / ext4_sb_get_desc_size(&fs->sb);
 586
 587         /* Block group descriptor table starts at the next block after
 588          * superblock */
 589         uint64_t block_id =
 590             ext4_fs_get_descriptor_block(&fs->sb, bgid, dsc_per_block);
 591
 592         uint32_t offset =
 593             (bgid % dsc_per_block) * ext4_sb_get_desc_size(&fs->sb);
 594
 595         int rc = ext4_block_get(fs->bdev, &ref->block, block_id);
 596         if (rc != EOK)
 597                 return rc;
 598
 599         ref->block_group = (void *)(ref->block.data + offset);
 600         ref->fs = fs;
 601         ref->index = bgid;
 602         ref->dirty = false;
 603
 604         if (!ext4_fs_verify_bg_csum(&fs->sb,
 605                                     bgid,
 606                                     ref->block_group)) {
 607                 ext4_dbg(DEBUG_FS,
 608                          DBG_WARN "Block group descriptor checksum failed."
 609                          "Block group index: %" PRIu32"\n",
 610                          bgid);
 611         }
 612
 613         if (ext4_bg_has_flag(ref->block_group, EXT4_BLOCK_GROUP_BLOCK_UNINIT)) {
 614                 rc = ext4_fs_init_block_bitmap(ref);
 615                 if (rc != EOK) {
 616                         ext4_block_set(fs->bdev, &ref->block);
 617                         return rc;
 618                 }
 619                 ext4_bg_clear_flag(ref->block_group,
 620                                    EXT4_BLOCK_GROUP_BLOCK_UNINIT);
 621
 622                 ref->dirty = true;
 623         }
 624
 625         if (ext4_bg_has_flag(ref->block_group, EXT4_BLOCK_GROUP_INODE_UNINIT)) {
 626                 rc = ext4_fs_init_inode_bitmap(ref);
 627                 if (rc != EOK) {
 628                         ext4_block_set(ref->fs->bdev, &ref->block);
 629                         return rc;
 630                 }
 631
 632                 ext4_bg_clear_flag(ref->block_group,
 633                                    EXT4_BLOCK_GROUP_INODE_UNINIT);
 634
 635                 if (!ext4_bg_has_flag(ref->block_group,
 636                                       EXT4_BLOCK_GROUP_ITABLE_ZEROED)) {
 637                         rc = ext4_fs_init_inode_table(ref);
 638                         if (rc != EOK) {
 639                                 ext4_block_set(fs->bdev, &ref->block);
 640                                 return rc;
 641                         }
 642
 643                         ext4_bg_set_flag(ref->block_group,
 644                                          EXT4_BLOCK_GROUP_ITABLE_ZEROED);
 645                 }
 646
 647                 ref->dirty = true;
 648         }
 649
 650         return EOK;
 651 }
 652
 653 int ext4_fs_put_block_group_ref(struct ext4_block_group_ref *ref)
 654 {
 655         /* Check if reference modified */
 656         if (ref->dirty) {
 657                 /* Compute new checksum of block group */
 658                 uint16_t checksum = ext4_fs_bg_checksum(
 659                     &ref->fs->sb, ref->index, ref->block_group);
 660
 661                 ref->block_group->checksum = to_le16(checksum);
 662
 663                 /* Mark block dirty for writing changes to physical device */
 664                 ref->block.dirty = true;
 665         }
 666
 667         /* Put back block, that contains block group descriptor */
 668         return ext4_block_set(ref->fs->bdev, &ref->block);
 669 }
 670
 671 #if CONFIG_META_CSUM_ENABLE
 672 static uint32_t ext4_fs_inode_checksum(struct ext4_inode_ref *inode_ref)
 673 {
 674         uint32_t checksum = 0;
 675         struct ext4_sblock *sb = &inode_ref->fs->sb;
 676         uint16_t inode_size = ext4_get16(sb, inode_size);
 677
 678         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
 679                 uint32_t orig_checksum;
 680
 681                 uint32_t ino_index = to_le32(inode_ref->index);
 682                 uint32_t ino_gen =
 683                         to_le32(ext4_inode_get_generation(inode_ref->inode));
 684
 685                 /* Preparation: temporarily set bg checksum to 0 */
 686                 orig_checksum = ext4_inode_get_checksum(sb, inode_ref->inode);
 687                 ext4_inode_set_checksum(sb, inode_ref->inode, 0);
 688
 689                 /* First calculate crc32 checksum against fs uuid */
 690                 checksum = ext4_crc32c(EXT4_CRC32_INIT, sb->uuid,
 691                                 sizeof(sb->uuid));
 692                 /* Then calculate crc32 checksum against inode number
 693                  * and inode generation */
 694                 checksum = ext4_crc32c(checksum, &ino_index,
 695                                      sizeof(ino_index));
 696                 checksum = ext4_crc32c(checksum, &ino_gen,
 697                                      sizeof(ino_gen));
 698                 /* Finally calculate crc32 checksum against
 699                  * the entire inode */
 700                 checksum = ext4_crc32c(checksum, inode_ref->inode,
 701                                 inode_size);
 702                 ext4_inode_set_checksum(sb, inode_ref->inode,
 703                                 orig_checksum);
 704
 705                 /* If inode size is not large enough to hold the
 706                  * upper 16bit of the checksum */
 707                 if (inode_size == EXT4_GOOD_OLD_INODE_SIZE)
 708                         checksum &= 0xFFFF;
 709
 710         }
 711         return checksum;
 712 }
 713 #else
 714 #define ext4_fs_inode_checksum(...) 0
 715 #endif
 716
 717 static void ext4_fs_set_inode_checksum(struct ext4_inode_ref *inode_ref)
 718 {
 719         struct ext4_sblock *sb = &inode_ref->fs->sb;
 720         if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 721                 return;
 722
 723         ext4_inode_set_checksum(sb, inode_ref->inode,
 724                                 ext4_fs_inode_checksum(inode_ref));
 725 }
 726
 727 #if CONFIG_META_CSUM_ENABLE
 728 static bool ext4_fs_verify_inode_csum(struct ext4_inode_ref *inode_ref)
 729 {
 730         struct ext4_sblock *sb = &inode_ref->fs->sb;
 731         if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 732                 return true;
 733
 734         return ext4_inode_get_checksum(sb, inode_ref->inode) ==
 735                 ext4_fs_inode_checksum(inode_ref);
 736 }
 737 #else
 738 #define ext4_fs_verify_inode_csum(...) true
 739 #endif
 740
 741 static int
 742 __ext4_fs_get_inode_ref(struct ext4_fs *fs, uint32_t index,
 743                         struct ext4_inode_ref *ref,
 744                         bool initialized)
 745 {
 746         /* Compute number of i-nodes, that fits in one data block */
 747         uint32_t inodes_per_group = ext4_get32(&fs->sb, inodes_per_group);
 748
 749         /*
 750          * Inode numbers are 1-based, but it is simpler to work with 0-based
 751          * when computing indices
 752          */
 753         index -= 1;
 754         uint32_t block_group = index / inodes_per_group;
 755         uint32_t offset_in_group = index % inodes_per_group;
 756
 757         /* Load block group, where i-node is located */
 758         struct ext4_block_group_ref bg_ref;
 759
 760         int rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
 761         if (rc != EOK) {
 762                 return rc;
 763         }
 764
 765         /* Load block address, where i-node table is located */
 766         uint32_t inode_table_start =
 767             ext4_bg_get_inode_table_first_block(bg_ref.block_group, &fs->sb);
 768
 769         /* Put back block group reference (not needed more) */
 770         rc = ext4_fs_put_block_group_ref(&bg_ref);
 771         if (rc != EOK) {
 772                 return rc;
 773         }
 774
 775         /* Compute position of i-node in the block group */
 776         uint16_t inode_size = ext4_get16(&fs->sb, inode_size);
 777         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
 778         uint32_t byte_offset_in_group = offset_in_group * inode_size;
 779
 780         /* Compute block address */
 781         ext4_fsblk_t block_id =
 782             inode_table_start + (byte_offset_in_group / block_size);
 783
 784         rc = ext4_block_get(fs->bdev, &ref->block, block_id);
 785         if (rc != EOK) {
 786                 return rc;
 787         }
 788
 789         /* Compute position of i-node in the data block */
 790         uint32_t offset_in_block = byte_offset_in_group % block_size;
 791         ref->inode = (struct ext4_inode *)(ref->block.data + offset_in_block);
 792
 793         /* We need to store the original value of index in the reference */
 794         ref->index = index + 1;
 795         ref->fs = fs;
 796         ref->dirty = false;
 797
 798         if (initialized && !ext4_fs_verify_inode_csum(ref)) {
 799                 ext4_dbg(DEBUG_FS,
 800                         DBG_WARN "Inode checksum failed."
 801                         "Inode: %" PRIu32"\n",
 802                         ref->index);
 803         }
 804
 805         return EOK;
 806 }
 807
 808 int ext4_fs_get_inode_ref(struct ext4_fs *fs, uint32_t index,
 809                           struct ext4_inode_ref *ref)
 810 {
 811         return __ext4_fs_get_inode_ref(fs, index, ref, true);
 812 }
 813
 814 int ext4_fs_put_inode_ref(struct ext4_inode_ref *ref)
 815 {
 816         /* Check if reference modified */
 817         if (ref->dirty) {
 818                 /* Mark block dirty for writing changes to physical device */
 819                 ext4_fs_set_inode_checksum(ref);
 820                 ref->block.dirty = true;
 821         }
 822
 823         /* Put back block, that contains i-node */
 824         return ext4_block_set(ref->fs->bdev, &ref->block);
 825 }
 826
 827 void ext4_fs_inode_blocks_init(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref)
 828 {
 829         int i;
 830         struct ext4_inode *inode = inode_ref->inode;
 831
 832         for (i = 0; i < EXT4_INODE_BLOCKS; i++)
 833                 inode->blocks[i] = 0;
 834
 835         (void)fs;
 836 #if CONFIG_EXTENT_ENABLE
 837         /* Initialize extents if needed */
 838         if (ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) {
 839                 ext4_inode_set_flag(inode, EXT4_INODE_FLAG_EXTENTS);
 840
 841                 /* Initialize extent root header */
 842                 ext4_extent_tree_init(inode_ref);
 843         }
 844 #endif
 845 }
 846
 847 uint32_t ext4_fs_correspond_inode_mode(int filetype)
 848 {
 849         switch (filetype) {
 850         case EXT4_DIRENTRY_DIR:
 851                 return EXT4_INODE_MODE_DIRECTORY;
 852         case EXT4_DIRENTRY_REG_FILE:
 853                 return EXT4_INODE_MODE_FILE;
 854         case EXT4_DIRENTRY_SYMLINK:
 855                 return EXT4_INODE_MODE_SOFTLINK;
 856         default:
 857                 /* FIXME: right now we only support 3 file type. */
 858                 ext4_assert(0);
 859         }
 860         return 0;
 861 }
 862
 863 int ext4_fs_alloc_inode(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
 864                         int filetype)
 865 {
 866         /* Check if newly allocated i-node will be a directory */
 867         bool is_dir;
 868         uint16_t inode_size = ext4_get16(&fs->sb, inode_size);
 869
 870         is_dir = (filetype == EXT4_DIRENTRY_DIR);
 871
 872         /* Allocate inode by allocation algorithm */
 873         uint32_t index;
 874         int rc = ext4_ialloc_alloc_inode(fs, &index, is_dir);
 875         if (rc != EOK)
 876                 return rc;
 877
 878         /* Load i-node from on-disk i-node table */
 879         rc = __ext4_fs_get_inode_ref(fs, index, inode_ref, false);
 880         if (rc != EOK) {
 881                 ext4_ialloc_free_inode(fs, index, is_dir);
 882                 return rc;
 883         }
 884
 885         /* Initialize i-node */
 886         struct ext4_inode *inode = inode_ref->inode;
 887
 888         uint32_t mode;
 889         if (is_dir) {
 890                 /*
 891                  * Default directory permissions to be compatible with other
 892                  * systems
 893                  * 0777 (octal) == rwxrwxrwx
 894                  */
 895
 896                 mode = 0777;
 897                 mode |= EXT4_INODE_MODE_DIRECTORY;
 898         } else {
 899                 /*
 900                  * Default file permissions to be compatible with other systems
 901                  * 0666 (octal) == rw-rw-rw-
 902                  */
 903
 904                 mode = 0666;
 905                 mode |= ext4_fs_correspond_inode_mode(filetype);
 906         }
 907         ext4_inode_set_mode(&fs->sb, inode, mode);
 908
 909         ext4_inode_set_links_count(inode, 0);
 910         ext4_inode_set_uid(inode, 0);
 911         ext4_inode_set_gid(inode, 0);
 912         ext4_inode_set_size(inode, 0);
 913         ext4_inode_set_access_time(inode, 0);
 914         ext4_inode_set_change_inode_time(inode, 0);
 915         ext4_inode_set_modification_time(inode, 0);
 916         ext4_inode_set_deletion_time(inode, 0);
 917         ext4_inode_set_blocks_count(&fs->sb, inode, 0);
 918         ext4_inode_set_flags(inode, 0);
 919         ext4_inode_set_generation(inode, 0);
 920         if (inode_size > EXT4_GOOD_OLD_INODE_SIZE)
 921                 ext4_inode_set_extra_isize(inode,
 922                                 sizeof(struct ext4_inode) -
 923                                 offsetof(struct ext4_inode,
 924                                         extra_isize));
 925
 926         /* Reset blocks array. For symbolic link inode, just
 927          * fill in blocks with 0 */
 928         if (ext4_inode_is_type(&fs->sb, inode, EXT4_INODE_MODE_SOFTLINK)) {
 929                 for (int i = 0; i < EXT4_INODE_BLOCKS; i++)
 930                         inode->blocks[i] = 0;
 931
 932         } else
 933                 ext4_fs_inode_blocks_init(fs, inode_ref);
 934
 935         inode_ref->dirty = true;
 936
 937         return EOK;
 938 }
 939
 940 int ext4_fs_free_inode(struct ext4_inode_ref *inode_ref)
 941 {
 942         struct ext4_fs *fs = inode_ref->fs;
 943         uint32_t offset;
 944         uint32_t suboff;
 945         int rc;
 946 #if CONFIG_EXTENT_ENABLE
 947         /* For extents must be data block destroyed by other way */
 948         if ((ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) &&
 949             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
 950                 /* Data structures are released during truncate operation... */
 951                 goto finish;
 952         }
 953 #endif
 954         /* Release all indirect (no data) blocks */
 955
 956         /* 1) Single indirect */
 957         ext4_fsblk_t fblock = ext4_inode_get_indirect_block(inode_ref->inode, 0);
 958         if (fblock != 0) {
 959                 int rc = ext4_balloc_free_block(inode_ref, fblock);
 960                 if (rc != EOK)
 961                         return rc;
 962
 963                 ext4_inode_set_indirect_block(inode_ref->inode, 0, 0);
 964         }
 965
 966         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
 967         uint32_t count = block_size / sizeof(uint32_t);
 968
 969         struct ext4_block block;
 970
 971         /* 2) Double indirect */
 972         fblock = ext4_inode_get_indirect_block(inode_ref->inode, 1);
 973         if (fblock != 0) {
 974                 int rc = ext4_block_get(fs->bdev, &block, fblock);
 975                 if (rc != EOK)
 976                         return rc;
 977
 978                 ext4_fsblk_t ind_block;
 979                 for (offset = 0; offset < count; ++offset) {
 980                         ind_block = to_le32(((uint32_t *)block.data)[offset]);
 981
 982                         if (ind_block == 0)
 983                                 continue;
 984                         rc = ext4_balloc_free_block(inode_ref, ind_block);
 985                         if (rc != EOK) {
 986                                 ext4_block_set(fs->bdev, &block);
 987                                 return rc;
 988                         }
 989
 990                 }
 991
 992                 ext4_block_set(fs->bdev, &block);
 993                 rc = ext4_balloc_free_block(inode_ref, fblock);
 994                 if (rc != EOK)
 995                         return rc;
 996
 997                 ext4_inode_set_indirect_block(inode_ref->inode, 1, 0);
 998         }
 999
1000         /* 3) Tripple indirect */
1001         struct ext4_block subblock;
1002         fblock = ext4_inode_get_indirect_block(inode_ref->inode, 2);
1003         if (fblock == 0)
1004                 goto finish;
1005         rc = ext4_block_get(fs->bdev, &block, fblock);
1006         if (rc != EOK)
1007                 return rc;
1008
1009         ext4_fsblk_t ind_block;
1010         for (offset = 0; offset < count; ++offset) {
1011                 ind_block = to_le32(((uint32_t *)block.data)[offset]);
1012
1013                 if (ind_block == 0)
1014                         continue;
1015                 rc = ext4_block_get(fs->bdev, &subblock,
1016                                 ind_block);
1017                 if (rc != EOK) {
1018                         ext4_block_set(fs->bdev, &block);
1019                         return rc;
1020                 }
1021
1022                 ext4_fsblk_t ind_subblk;
1023                 for (suboff = 0; suboff < count; ++suboff) {
1024                         ind_subblk = to_le32(((uint32_t *)subblock.data)[suboff]);
1025
1026                         if (ind_subblk == 0)
1027                                 continue;
1028                         rc = ext4_balloc_free_block(inode_ref, ind_subblk);
1029                         if (rc != EOK) {
1030                                 ext4_block_set(fs->bdev, &subblock);
1031                                 ext4_block_set(fs->bdev, &block);
1032                                 return rc;
1033                         }
1034
1035                 }
1036
1037                 ext4_block_set(fs->bdev, &subblock);
1038
1039                 rc = ext4_balloc_free_block(inode_ref,
1040                                 ind_block);
1041                 if (rc != EOK) {
1042                         ext4_block_set(fs->bdev, &block);
1043                         return rc;
1044                 }
1045
1046         }
1047
1048         ext4_block_set(fs->bdev, &block);
1049         rc = ext4_balloc_free_block(inode_ref, fblock);
1050         if (rc != EOK)
1051                 return rc;
1052
1053         ext4_inode_set_indirect_block(inode_ref->inode, 2, 0);
1054 finish:
1055         /* Mark inode dirty for writing to the physical device */
1056         inode_ref->dirty = true;
1057
1058         /* Free block with extended attributes if present */
1059         ext4_fsblk_t xattr_block =
1060             ext4_inode_get_file_acl(inode_ref->inode, &fs->sb);
1061         if (xattr_block) {
1062                 int rc = ext4_balloc_free_block(inode_ref, xattr_block);
1063                 if (rc != EOK)
1064                         return rc;
1065
1066                 ext4_inode_set_file_acl(inode_ref->inode, &fs->sb, 0);
1067         }
1068
1069         /* Free inode by allocator */
1070         if (ext4_inode_is_type(&fs->sb, inode_ref->inode,
1071                                EXT4_INODE_MODE_DIRECTORY))
1072                 rc = ext4_ialloc_free_inode(fs, inode_ref->index, true);
1073         else
1074                 rc = ext4_ialloc_free_inode(fs, inode_ref->index, false);
1075
1076         return rc;
1077 }
1078
1079
1080 /**@brief Release data block from i-node
1081  * @param inode_ref I-node to release block from
1082  * @param iblock    Logical block to be released
1083  * @return Error code
1084  */
1085 static int ext4_fs_release_inode_block(struct ext4_inode_ref *inode_ref,
1086                                 uint32_t iblock)
1087 {
1088         ext4_fsblk_t fblock;
1089
1090         struct ext4_fs *fs = inode_ref->fs;
1091
1092         /* Extents are handled otherwise = there is not support in this function
1093          */
1094         ext4_assert(!(
1095             ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS) &&
1096             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))));
1097
1098         struct ext4_inode *inode = inode_ref->inode;
1099
1100         /* Handle simple case when we are dealing with direct reference */
1101         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1102                 fblock = ext4_inode_get_direct_block(inode, iblock);
1103
1104                 /* Sparse file */
1105                 if (fblock == 0)
1106                         return EOK;
1107
1108                 ext4_inode_set_direct_block(inode, iblock, 0);
1109                 return ext4_balloc_free_block(inode_ref, fblock);
1110         }
1111
1112         /* Determine the indirection level needed to get the desired block */
1113         unsigned int level = 0;
1114         unsigned int i;
1115         for (i = 1; i < 4; i++) {
1116                 if (iblock < fs->inode_block_limits[i]) {
1117                         level = i;
1118                         break;
1119                 }
1120         }
1121
1122         if (level == 0)
1123                 return EIO;
1124
1125         /* Compute offsets for the topmost level */
1126         uint64_t block_offset_in_level =
1127             iblock - fs->inode_block_limits[level - 1];
1128         ext4_fsblk_t current_block =
1129             ext4_inode_get_indirect_block(inode, level - 1);
1130         uint32_t offset_in_block =
1131             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1132
1133         /*
1134          * Navigate through other levels, until we find the block number
1135          * or find null reference meaning we are dealing with sparse file
1136          */
1137         struct ext4_block block;
1138
1139         while (level > 0) {
1140
1141                 /* Sparse check */
1142                 if (current_block == 0)
1143                         return EOK;
1144
1145                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1146                 if (rc != EOK)
1147                         return rc;
1148
1149                 current_block =
1150                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1151
1152                 /* Set zero if physical data block address found */
1153                 if (level == 1) {
1154                         ((uint32_t *)block.data)[offset_in_block] = to_le32(0);
1155                         block.dirty = true;
1156                 }
1157
1158                 rc = ext4_block_set(fs->bdev, &block);
1159                 if (rc != EOK)
1160                         return rc;
1161
1162                 level--;
1163
1164                 /*
1165                  * If we are on the last level, break here as
1166                  * there is no next level to visit
1167                  */
1168                 if (level == 0)
1169                         break;
1170
1171                 /* Visit the next level */
1172                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1173                 offset_in_block = block_offset_in_level /
1174                                   fs->inode_blocks_per_level[level - 1];
1175         }
1176
1177         fblock = current_block;
1178         if (fblock == 0)
1179                 return EOK;
1180
1181         /* Physical block is not referenced, it can be released */
1182         return ext4_balloc_free_block(inode_ref, fblock);
1183 }
1184
1185 int ext4_fs_truncate_inode(struct ext4_inode_ref *inode_ref, uint64_t new_size)
1186 {
1187         struct ext4_sblock *sb = &inode_ref->fs->sb;
1188         uint32_t i;
1189
1190         /* Check flags, if i-node can be truncated */
1191         if (!ext4_inode_can_truncate(sb, inode_ref->inode))
1192                 return EINVAL;
1193
1194         /* If sizes are equal, nothing has to be done. */
1195         uint64_t old_size = ext4_inode_get_size(sb, inode_ref->inode);
1196         if (old_size == new_size)
1197                 return EOK;
1198
1199         /* It's not supported to make the larger file by truncate operation */
1200         if (old_size < new_size)
1201                 return EINVAL;
1202
1203         if (ext4_inode_is_type(sb, inode_ref->inode, EXT4_INODE_MODE_SOFTLINK)
1204                         && old_size < sizeof(inode_ref->inode->blocks)
1205                         && !ext4_inode_get_blocks_count(sb, inode_ref->inode)) {
1206                 char *content = (char *)inode_ref->inode->blocks;
1207                 memset(content + new_size, 0,
1208                         sizeof(inode_ref->inode->blocks) - new_size);
1209                 ext4_inode_set_size(inode_ref->inode, new_size);
1210                 inode_ref->dirty = true;
1211
1212                 return EOK;
1213         }
1214
1215         /* Compute how many blocks will be released */
1216         uint32_t block_size = ext4_sb_get_block_size(sb);
1217         uint32_t new_blocks_count = (new_size + block_size - 1) /
1218                                     block_size;
1219         uint32_t old_blocks_count = (old_size + block_size - 1) /
1220                                     block_size;
1221         uint32_t diff_blocks_count = old_blocks_count - new_blocks_count;
1222 #if CONFIG_EXTENT_ENABLE
1223         if ((ext4_sb_feature_incom(sb, EXT4_FINCOM_EXTENTS)) &&
1224             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1225
1226                 /* Extents require special operation */
1227                 if (diff_blocks_count) {
1228                         int rc = ext4_extent_remove_space(inode_ref,
1229                                         new_blocks_count, EXT_MAX_BLOCKS);
1230                         if (rc != EOK)
1231                                 return rc;
1232
1233                 }
1234         } else
1235 #endif
1236         {
1237                 /* Release data blocks from the end of file */
1238
1239                 /* Starting from 1 because of logical blocks are numbered from 0
1240                  */
1241                 for (i = 0; i < diff_blocks_count; ++i) {
1242                         int rc = ext4_fs_release_inode_block(
1243                             inode_ref, new_blocks_count + i);
1244                         if (rc != EOK)
1245                                 return rc;
1246                 }
1247         }
1248
1249         /* Update i-node */
1250         ext4_inode_set_size(inode_ref->inode, new_size);
1251         inode_ref->dirty = true;
1252
1253         return EOK;
1254 }
1255
1256 /**@brief Compute 'goal' for inode index
1257  * @param inode_ref Reference to inode, to allocate block for
1258  * @return goal
1259  */
1260 ext4_fsblk_t ext4_fs_inode_to_goal_block(struct ext4_inode_ref *inode_ref)
1261 {
1262         uint32_t group_inodes =
1263                 ext4_get32(&inode_ref->fs->sb, inodes_per_group);
1264         return (inode_ref->index - 1) / group_inodes;
1265 }
1266
1267 /**@brief Compute 'goal' for allocation algorithm (For blockmap).
1268  * @param inode_ref Reference to inode, to allocate block for
1269  * @param goal
1270  * @return error code
1271  */
1272 int ext4_fs_indirect_find_goal(struct ext4_inode_ref *inode_ref,
1273                                 ext4_fsblk_t *goal)
1274 {
1275         struct ext4_sblock *sb = &inode_ref->fs->sb;
1276         *goal = 0;
1277
1278         uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
1279         uint32_t block_size = ext4_sb_get_block_size(sb);
1280         uint32_t inode_block_count = inode_size / block_size;
1281
1282         if (inode_size % block_size != 0)
1283                 inode_block_count++;
1284
1285         /* If inode has some blocks, get last block address + 1 */
1286         if (inode_block_count > 0) {
1287                 int rc = ext4_fs_get_inode_data_block_index(
1288                     inode_ref, inode_block_count - 1, goal, false);
1289                 if (rc != EOK)
1290                         return rc;
1291
1292                 if (*goal != 0) {
1293                         (*goal)++;
1294                         return rc;
1295                 }
1296
1297                 /* If goal == 0, sparse file -> continue */
1298         }
1299
1300         /* Identify block group of inode */
1301
1302         uint32_t inodes_per_group = ext4_get32(sb, inodes_per_group);
1303         uint32_t block_group = (inode_ref->index - 1) / inodes_per_group;
1304         block_size = ext4_sb_get_block_size(sb);
1305
1306         /* Load block group reference */
1307         struct ext4_block_group_ref bg_ref;
1308         int rc =
1309             ext4_fs_get_block_group_ref(inode_ref->fs, block_group, &bg_ref);
1310         if (rc != EOK)
1311                 return rc;
1312
1313         /* Compute indexes */
1314         uint32_t block_group_count = ext4_block_group_cnt(sb);
1315         ext4_fsblk_t inode_table_first_block =
1316             ext4_bg_get_inode_table_first_block(bg_ref.block_group, sb);
1317         uint16_t inode_table_item_size = ext4_get16(sb, inode_size);
1318         uint32_t inode_table_bytes;
1319
1320         /* Check for last block group */
1321         if (block_group < block_group_count - 1) {
1322                 inode_table_bytes = inodes_per_group * inode_table_item_size;
1323         } else {
1324                 /* Last block group could be smaller */
1325                 uint32_t inodes_count_total = ext4_get32(sb, inodes_count);
1326
1327                 inode_table_bytes =
1328                     (inodes_count_total -
1329                      ((block_group_count - 1) * inodes_per_group)) *
1330                     inode_table_item_size;
1331         }
1332
1333         ext4_fsblk_t inode_table_blocks = inode_table_bytes / block_size;
1334
1335         if (inode_table_bytes % block_size)
1336                 inode_table_blocks++;
1337
1338         *goal = inode_table_first_block + inode_table_blocks;
1339
1340         return ext4_fs_put_block_group_ref(&bg_ref);
1341 }
1342
1343 static int ext4_fs_get_inode_data_block_idx(struct ext4_inode_ref *inode_ref,
1344                                        uint64_t iblock, ext4_fsblk_t *fblock,
1345                                        bool extent_create,
1346                                        bool support_unwritten __unused)
1347 {
1348         struct ext4_fs *fs = inode_ref->fs;
1349
1350         /* For empty file is situation simple */
1351         if (ext4_inode_get_size(&fs->sb, inode_ref->inode) == 0) {
1352                 *fblock = 0;
1353                 return EOK;
1354         }
1355
1356         ext4_fsblk_t current_block;
1357
1358         (void)extent_create;
1359 #if CONFIG_EXTENT_ENABLE
1360         /* Handle i-node using extents */
1361         if ((ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) &&
1362             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1363
1364                 ext4_fsblk_t current_fsblk;
1365                 int rc = ext4_extent_get_blocks(inode_ref, iblock, 1,
1366                                 &current_fsblk, extent_create, NULL);
1367                 if (rc != EOK)
1368                         return rc;
1369
1370                 current_block = current_fsblk;
1371                 *fblock = current_block;
1372
1373                 ext4_assert(*fblock || support_unwritten);
1374                 return EOK;
1375         }
1376 #endif
1377
1378         struct ext4_inode *inode = inode_ref->inode;
1379
1380         /* Direct block are read directly from array in i-node structure */
1381         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1382                 current_block =
1383                     ext4_inode_get_direct_block(inode, (uint32_t)iblock);
1384                 *fblock = current_block;
1385                 return EOK;
1386         }
1387
1388         /* Determine indirection level of the target block */
1389         unsigned int level = 0;
1390         unsigned int i;
1391         for (i = 1; i < 4; i++) {
1392                 if (iblock < fs->inode_block_limits[i]) {
1393                         level = i;
1394                         break;
1395                 }
1396         }
1397
1398         if (level == 0)
1399                 return EIO;
1400
1401         /* Compute offsets for the topmost level */
1402         uint64_t block_offset_in_level =
1403             iblock - fs->inode_block_limits[level - 1];
1404         current_block = ext4_inode_get_indirect_block(inode, level - 1);
1405         uint32_t offset_in_block =
1406             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1407
1408         /* Sparse file */
1409         if (current_block == 0) {
1410                 *fblock = 0;
1411                 return EOK;
1412         }
1413
1414         struct ext4_block block;
1415
1416         /*
1417          * Navigate through other levels, until we find the block number
1418          * or find null reference meaning we are dealing with sparse file
1419          */
1420         while (level > 0) {
1421                 /* Load indirect block */
1422                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1423                 if (rc != EOK)
1424                         return rc;
1425
1426                 /* Read block address from indirect block */
1427                 current_block =
1428                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1429
1430                 /* Put back indirect block untouched */
1431                 rc = ext4_block_set(fs->bdev, &block);
1432                 if (rc != EOK)
1433                         return rc;
1434
1435                 /* Check for sparse file */
1436                 if (current_block == 0) {
1437                         *fblock = 0;
1438                         return EOK;
1439                 }
1440
1441                 /* Jump to the next level */
1442                 level--;
1443
1444                 /* Termination condition - we have address of data block loaded
1445                  */
1446                 if (level == 0)
1447                         break;
1448
1449                 /* Visit the next level */
1450                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1451                 offset_in_block = block_offset_in_level /
1452                                   fs->inode_blocks_per_level[level - 1];
1453         }
1454
1455         *fblock = current_block;
1456
1457         return EOK;
1458 }
1459
1460
1461 int ext4_fs_get_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1462                                        uint64_t iblock, ext4_fsblk_t *fblock,
1463                                        bool support_unwritten)
1464 {
1465         return ext4_fs_get_inode_data_block_idx(inode_ref, iblock, fblock,
1466                         false, support_unwritten);
1467 }
1468
1469 int ext4_fs_init_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1470                                        uint64_t iblock, ext4_fsblk_t *fblock)
1471 {
1472         return ext4_fs_get_inode_data_block_idx(inode_ref, iblock, fblock,
1473                         true, true);
1474 }
1475
1476 static int ext4_fs_set_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1477                                        uint64_t iblock, ext4_fsblk_t fblock)
1478 {
1479         struct ext4_fs *fs = inode_ref->fs;
1480
1481 #if CONFIG_EXTENT_ENABLE
1482         /* Handle inode using extents */
1483         if ((ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) &&
1484             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1485                 /* Not reachable */
1486                 return ENOTSUP;
1487         }
1488 #endif
1489
1490         /* Handle simple case when we are dealing with direct reference */
1491         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1492                 ext4_inode_set_direct_block(inode_ref->inode, (uint32_t)iblock,
1493                                             (uint32_t)fblock);
1494                 inode_ref->dirty = true;
1495
1496                 return EOK;
1497         }
1498
1499         /* Determine the indirection level needed to get the desired block */
1500         unsigned int level = 0;
1501         unsigned int i;
1502         for (i = 1; i < 4; i++) {
1503                 if (iblock < fs->inode_block_limits[i]) {
1504                         level = i;
1505                         break;
1506                 }
1507         }
1508
1509         if (level == 0)
1510                 return EIO;
1511
1512         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
1513
1514         /* Compute offsets for the topmost level */
1515         uint64_t block_offset_in_level =
1516             iblock - fs->inode_block_limits[level - 1];
1517         ext4_fsblk_t current_block =
1518             ext4_inode_get_indirect_block(inode_ref->inode, level - 1);
1519         uint32_t offset_in_block =
1520             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1521
1522         ext4_fsblk_t new_block_addr;
1523
1524         struct ext4_block block;
1525         struct ext4_block new_block;
1526
1527         /* Is needed to allocate indirect block on the i-node level */
1528         if (current_block == 0) {
1529                 /* Allocate new indirect block */
1530                 ext4_fsblk_t goal;
1531                 int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
1532                 if (rc != EOK)
1533                         return rc;
1534
1535                 rc = ext4_balloc_alloc_block(inode_ref,
1536                                              goal,
1537                                              &new_block_addr);
1538                 if (rc != EOK)
1539                         return rc;
1540
1541                 /* Update i-node */
1542                 ext4_inode_set_indirect_block(inode_ref->inode, level - 1,
1543                                               (uint32_t)new_block_addr);
1544                 inode_ref->dirty = true;
1545
1546                 /* Load newly allocated block */
1547                 rc = ext4_block_get_noread(fs->bdev, &new_block, new_block_addr);
1548                 if (rc != EOK) {
1549                         ext4_balloc_free_block(inode_ref, new_block_addr);
1550                         return rc;
1551                 }
1552
1553                 /* Initialize new block */
1554                 memset(new_block.data, 0, block_size);
1555                 new_block.dirty = true;
1556
1557                 /* Put back the allocated block */
1558                 rc = ext4_block_set(fs->bdev, &new_block);
1559                 if (rc != EOK)
1560                         return rc;
1561
1562                 current_block = new_block_addr;
1563         }
1564
1565         /*
1566          * Navigate through other levels, until we find the block number
1567          * or find null reference meaning we are dealing with sparse file
1568          */
1569         while (level > 0) {
1570                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1571                 if (rc != EOK)
1572                         return rc;
1573
1574                 current_block =
1575                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1576
1577                 if ((level > 1) && (current_block == 0)) {
1578                         ext4_fsblk_t goal;
1579                         rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
1580                         if (rc != EOK) {
1581                                 ext4_block_set(fs->bdev, &block);
1582                                 return rc;
1583                         }
1584
1585                         /* Allocate new block */
1586                         rc =
1587                             ext4_balloc_alloc_block(inode_ref, goal, &new_block_addr);
1588                         if (rc != EOK) {
1589                                 ext4_block_set(fs->bdev, &block);
1590                                 return rc;
1591                         }
1592
1593                         /* Load newly allocated block */
1594                         rc = ext4_block_get_noread(fs->bdev, &new_block,
1595                                             new_block_addr);
1596
1597                         if (rc != EOK) {
1598                                 ext4_block_set(fs->bdev, &block);
1599                                 return rc;
1600                         }
1601
1602                         /* Initialize allocated block */
1603                         memset(new_block.data, 0, block_size);
1604                         new_block.dirty = true;
1605
1606                         rc = ext4_block_set(fs->bdev, &new_block);
1607                         if (rc != EOK) {
1608                                 ext4_block_set(fs->bdev, &block);
1609                                 return rc;
1610                         }
1611
1612                         /* Write block address to the parent */
1613                         ((uint32_t *)block.data)[offset_in_block] =
1614                             to_le32((uint32_t)new_block_addr);
1615                         block.dirty = true;
1616                         current_block = new_block_addr;
1617                 }
1618
1619                 /* Will be finished, write the fblock address */
1620                 if (level == 1) {
1621                         ((uint32_t *)block.data)[offset_in_block] =
1622                             to_le32((uint32_t)fblock);
1623                         block.dirty = true;
1624                 }
1625
1626                 rc = ext4_block_set(fs->bdev, &block);
1627                 if (rc != EOK)
1628                         return rc;
1629
1630                 level--;
1631
1632                 /*
1633                  * If we are on the last level, break here as
1634                  * there is no next level to visit
1635                  */
1636                 if (level == 0)
1637                         break;
1638
1639                 /* Visit the next level */
1640                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1641                 offset_in_block = block_offset_in_level /
1642                                   fs->inode_blocks_per_level[level - 1];
1643         }
1644
1645         return EOK;
1646 }
1647
1648
1649 int ext4_fs_append_inode_block(struct ext4_inode_ref *inode_ref,
1650                                ext4_fsblk_t *fblock, uint32_t *iblock)
1651 {
1652 #if CONFIG_EXTENT_ENABLE
1653         /* Handle extents separately */
1654         if ((ext4_sb_feature_incom(&inode_ref->fs->sb, EXT4_FINCOM_EXTENTS)) &&
1655             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1656                 int rc;
1657                 ext4_fsblk_t current_fsblk;
1658                 struct ext4_sblock *sb = &inode_ref->fs->sb;
1659                 uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
1660                 uint32_t block_size = ext4_sb_get_block_size(sb);
1661                 *iblock = (inode_size + block_size - 1) /
1662                                     block_size;
1663
1664                 rc = ext4_extent_get_blocks(inode_ref, *iblock, 1,
1665                                 &current_fsblk, true, NULL);
1666
1667
1668                 *fblock = current_fsblk;
1669                 ext4_assert(*fblock);
1670
1671                 ext4_inode_set_size(inode_ref->inode,
1672                                     inode_size + block_size);
1673                 inode_ref->dirty = true;
1674
1675
1676                 return rc;
1677         }
1678 #endif
1679         struct ext4_sblock *sb = &inode_ref->fs->sb;
1680
1681         /* Compute next block index and allocate data block */
1682         uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
1683         uint32_t block_size = ext4_sb_get_block_size(sb);
1684
1685         /* Align size i-node size */
1686         if ((inode_size % block_size) != 0)
1687                 inode_size += block_size - (inode_size % block_size);
1688
1689         /* Logical blocks are numbered from 0 */
1690         uint32_t new_block_idx = inode_size / block_size;
1691
1692         /* Allocate new physical block */
1693         ext4_fsblk_t goal, phys_block;
1694         int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
1695         if (rc != EOK)
1696                 return rc;
1697
1698         rc = ext4_balloc_alloc_block(inode_ref, goal, &phys_block);
1699         if (rc != EOK)
1700                 return rc;
1701
1702         /* Add physical block address to the i-node */
1703         rc = ext4_fs_set_inode_data_block_index(inode_ref, new_block_idx,
1704                                                 phys_block);
1705         if (rc != EOK) {
1706                 ext4_balloc_free_block(inode_ref, phys_block);
1707                 return rc;
1708         }
1709
1710         /* Update i-node */
1711         ext4_inode_set_size(inode_ref->inode, inode_size + block_size);
1712         inode_ref->dirty = true;
1713
1714         *fblock = phys_block;
1715         *iblock = new_block_idx;
1716
1717         return EOK;
1718 }
1719
1720 void ext4_fs_inode_links_count_inc(struct ext4_inode_ref *inode_ref)
1721 {
1722         uint16_t link;
1723
1724         link = ext4_inode_get_links_count(inode_ref->inode);
1725         link++;
1726         ext4_inode_set_links_count(inode_ref->inode, link);
1727
1728         bool is_dx =
1729             ext4_sb_feature_com(&inode_ref->fs->sb, EXT4_FCOM_DIR_INDEX) &&
1730             ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_INDEX);
1731
1732         if (is_dx && link > 1) {
1733                 if (link >= EXT4_LINK_MAX || link == 2) {
1734                         ext4_inode_set_links_count(inode_ref->inode, 1);
1735
1736                         uint32_t v =
1737                             ext4_get32(&inode_ref->fs->sb, features_read_only);
1738                         v |= EXT4_FRO_COM_DIR_NLINK;
1739                         ext4_set32(&inode_ref->fs->sb, features_read_only, v);
1740                 }
1741         }
1742 }
1743
1744 void ext4_fs_inode_links_count_dec(struct ext4_inode_ref *inode_ref)
1745 {
1746         uint16_t links = ext4_inode_get_links_count(inode_ref->inode);
1747         if (!ext4_inode_is_type(&inode_ref->fs->sb, inode_ref->inode,
1748                                 EXT4_INODE_MODE_DIRECTORY)) {
1749                 if (links > 0)
1750                         ext4_inode_set_links_count(inode_ref->inode, links - 1);
1751                 return;
1752         }
1753
1754         if (links > 2)
1755                 ext4_inode_set_links_count(inode_ref->inode, links - 1);
1756 }
1757
1758 /**
1759  * @}
1760  */