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