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(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(bg_ref->fs->bdev, &block_bitmap, bitmap_block_addr);
 397         if (rc != EOK)
 398                 return rc;
 399
 400         /* Initialize all bitmap bits to zero */
 401         uint32_t block_size = ext4_sb_get_block_size(&bg_ref->fs->sb);
 402         uint32_t inodes_per_group =
 403             ext4_get32(&bg_ref->fs->sb, inodes_per_group);
 404
 405         memset(block_bitmap.data, 0, (inodes_per_group + 7) / 8);
 406
 407         uint32_t start_bit = inodes_per_group;
 408         uint32_t end_bit = block_size * 8;
 409
 410         uint32_t i;
 411         for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
 412                 ext4_bmap_bit_set(block_bitmap.data, i);
 413
 414         if (i < end_bit)
 415                 memset(block_bitmap.data + (i >> 3), 0xff, (end_bit - i) >> 3);
 416
 417         block_bitmap.dirty = true;
 418
 419         ext4_ialloc_set_bitmap_csum(&bg_ref->fs->sb,
 420                                     bg_ref->block_group,
 421                                     block_bitmap.data);
 422         bg_ref->dirty = true;
 423
 424         /* Save bitmap */
 425         return ext4_block_set(bg_ref->fs->bdev, &block_bitmap);
 426 }
 427
 428 /**@brief Initialize i-node table in block group.
 429  * @param bg_ref Reference to block group
 430  * @return Error code
 431  */
 432 static int ext4_fs_init_inode_table(struct ext4_block_group_ref *bg_ref)
 433 {
 434         struct ext4_sblock *sb = &bg_ref->fs->sb;
 435
 436         uint32_t inode_size = ext4_get32(sb, inode_size);
 437         uint32_t block_size = ext4_sb_get_block_size(sb);
 438         uint32_t inodes_per_block = block_size / inode_size;
 439         uint32_t inodes_in_group = ext4_inodes_in_group_cnt(sb, bg_ref->index);
 440         uint32_t table_blocks = inodes_in_group / inodes_per_block;
 441         ext4_fsblk_t fblock;
 442
 443         if (inodes_in_group % inodes_per_block)
 444                 table_blocks++;
 445
 446         /* Compute initialization bounds */
 447         ext4_fsblk_t first_block =
 448             ext4_bg_get_inode_table_first_block(bg_ref->block_group, sb);
 449
 450         ext4_fsblk_t last_block = first_block + table_blocks - 1;
 451
 452         /* Initialization of all itable blocks */
 453         for (fblock = first_block; fblock <= last_block; ++fblock) {
 454
 455                 struct ext4_block block;
 456                 int rc = ext4_block_get(bg_ref->fs->bdev, &block, fblock);
 457                 if (rc != EOK)
 458                         return rc;
 459
 460                 memset(block.data, 0, block_size);
 461                 block.dirty = true;
 462
 463                 ext4_block_set(bg_ref->fs->bdev, &block);
 464                 if (rc != EOK)
 465                         return rc;
 466         }
 467
 468         return EOK;
 469 }
 470
 471 static ext4_fsblk_t ext4_fs_get_descriptor_block(struct ext4_sblock *s,
 472                                              uint32_t bgid,
 473                                              uint32_t dsc_per_block)
 474 {
 475         uint32_t first_meta_bg, dsc_id;
 476
 477         int has_super = 0;
 478
 479         dsc_id = bgid / dsc_per_block;
 480         first_meta_bg = ext4_sb_first_meta_bg(s);
 481
 482         if (!ext4_sb_feature_incom(s, EXT4_FINCOM_META_BG) ||
 483             dsc_id < first_meta_bg)
 484                 return ext4_get32(s, first_data_block) + dsc_id + 1;
 485
 486         if (ext4_sb_is_super_in_bg(s, bgid))
 487                 has_super = 1;
 488
 489         return (has_super + ext4_fs_first_bg_block_no(s, bgid));
 490 }
 491
 492 int ext4_fs_get_block_group_ref(struct ext4_fs *fs, uint32_t bgid,
 493                                 struct ext4_block_group_ref *ref)
 494 {
 495         /* Compute number of descriptors, that fits in one data block */
 496         uint32_t dsc_per_block =
 497             ext4_sb_get_block_size(&fs->sb) / ext4_sb_get_desc_size(&fs->sb);
 498
 499         /* Block group descriptor table starts at the next block after
 500          * superblock */
 501         uint64_t block_id =
 502             ext4_fs_get_descriptor_block(&fs->sb, bgid, dsc_per_block);
 503
 504         uint32_t offset =
 505             (bgid % dsc_per_block) * ext4_sb_get_desc_size(&fs->sb);
 506
 507         int rc = ext4_block_get(fs->bdev, &ref->block, block_id);
 508         if (rc != EOK)
 509                 return rc;
 510
 511         ref->block_group = (void *)(ref->block.data + offset);
 512         ref->fs = fs;
 513         ref->index = bgid;
 514         ref->dirty = false;
 515
 516         if (ext4_bg_has_flag(ref->block_group, EXT4_BLOCK_GROUP_BLOCK_UNINIT)) {
 517                 rc = ext4_fs_init_block_bitmap(ref);
 518                 if (rc != EOK) {
 519                         ext4_block_set(fs->bdev, &ref->block);
 520                         return rc;
 521                 }
 522                 ext4_bg_clear_flag(ref->block_group,
 523                                    EXT4_BLOCK_GROUP_BLOCK_UNINIT);
 524
 525                 ref->dirty = true;
 526         }
 527
 528         if (ext4_bg_has_flag(ref->block_group, EXT4_BLOCK_GROUP_INODE_UNINIT)) {
 529                 rc = ext4_fs_init_inode_bitmap(ref);
 530                 if (rc != EOK) {
 531                         ext4_block_set(ref->fs->bdev, &ref->block);
 532                         return rc;
 533                 }
 534
 535                 ext4_bg_clear_flag(ref->block_group,
 536                                    EXT4_BLOCK_GROUP_INODE_UNINIT);
 537
 538                 if (!ext4_bg_has_flag(ref->block_group,
 539                                       EXT4_BLOCK_GROUP_ITABLE_ZEROED)) {
 540                         rc = ext4_fs_init_inode_table(ref);
 541                         if (rc != EOK) {
 542                                 ext4_block_set(fs->bdev, &ref->block);
 543                                 return rc;
 544                         }
 545
 546                         ext4_bg_set_flag(ref->block_group,
 547                                          EXT4_BLOCK_GROUP_ITABLE_ZEROED);
 548                 }
 549
 550                 ref->dirty = true;
 551         }
 552
 553         return EOK;
 554 }
 555
 556 /*
 557  * BIG FAT NOTES:
 558  *       Currently we do not verify the checksum of block_group_desc
 559  *       and inode.
 560  */
 561
 562 /**@brief  Compute checksum of block group descriptor.
 563  * @param sb   Superblock
 564  * @param bgid Index of block group in the filesystem
 565  * @param bg   Block group to compute checksum for
 566  * @return Checksum value
 567  */
 568 static uint16_t ext4_fs_bg_checksum(struct ext4_sblock *sb, uint32_t bgid,
 569                                     struct ext4_bgroup *bg)
 570 {
 571         /* If checksum not supported, 0 will be returned */
 572         uint16_t crc = 0;
 573
 574         /* Compute the checksum only if the filesystem supports it */
 575         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
 576                 /* Use metadata_csum algorithm instead */
 577                 uint32_t le32_bgid = to_le32(bgid);
 578                 uint32_t orig_checksum, checksum;
 579
 580                 /* Preparation: temporarily set bg checksum to 0 */
 581                 orig_checksum = bg->checksum;
 582                 bg->checksum = 0;
 583
 584                 /* First calculate crc32 checksum against fs uuid */
 585                 checksum = ext4_crc32c(~0, sb->uuid, sizeof(sb->uuid));
 586                 /* Then calculate crc32 checksum against bgid */
 587                 checksum = ext4_crc32c(checksum, &le32_bgid,
 588                                      sizeof(bgid));
 589                 /* Finally calculate crc32 checksum against block_group_desc */
 590                 checksum = ext4_crc32c(checksum, bg,
 591                                      ext4_sb_get_desc_size(sb));
 592                 bg->checksum = orig_checksum;
 593
 594                 crc = checksum & 0xFFFF;
 595         } else if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_GDT_CSUM)) {
 596                 uint8_t *base = (uint8_t *)bg;
 597                 uint8_t *checksum = (uint8_t *)&bg->checksum;
 598
 599                 uint32_t offset = (uint32_t)(checksum - base);
 600
 601                 /* Convert block group index to little endian */
 602                 uint32_t le_group = to_le32(bgid);
 603
 604                 /* Initialization */
 605                 crc = ext4_bg_crc16(~0, sb->uuid, sizeof(sb->uuid));
 606
 607                 /* Include index of block group */
 608                 crc =
 609                     ext4_bg_crc16(crc, (uint8_t *)&le_group, sizeof(le_group));
 610
 611                 /* Compute crc from the first part (stop before checksum field)
 612                  */
 613                 crc = ext4_bg_crc16(crc, (uint8_t *)bg, offset);
 614
 615                 /* Skip checksum */
 616                 offset += sizeof(bg->checksum);
 617
 618                 /* Checksum of the rest of block group descriptor */
 619                 if ((ext4_sb_feature_incom(sb, EXT4_FINCOM_64BIT)) &&
 620                     (offset < ext4_sb_get_desc_size(sb)))
 621
 622                         crc = ext4_bg_crc16(crc, ((uint8_t *)bg) + offset,
 623                                             ext4_sb_get_desc_size(sb) - offset);
 624         }
 625         return crc;
 626 }
 627
 628 int ext4_fs_put_block_group_ref(struct ext4_block_group_ref *ref)
 629 {
 630         /* Check if reference modified */
 631         if (ref->dirty) {
 632                 /* Compute new checksum of block group */
 633                 uint16_t checksum = ext4_fs_bg_checksum(
 634                     &ref->fs->sb, ref->index, ref->block_group);
 635
 636                 ref->block_group->checksum = to_le16(checksum);
 637
 638                 /* Mark block dirty for writing changes to physical device */
 639                 ref->block.dirty = true;
 640         }
 641
 642         /* Put back block, that contains block group descriptor */
 643         return ext4_block_set(ref->fs->bdev, &ref->block);
 644 }
 645
 646 static uint32_t ext4_fs_inode_checksum(struct ext4_inode_ref *inode_ref)
 647 {
 648         uint32_t checksum = 0;
 649         struct ext4_sblock *sb = &inode_ref->fs->sb;
 650         uint16_t inode_size = ext4_get16(sb, inode_size);
 651
 652         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
 653                 uint32_t orig_checksum;
 654
 655                 uint32_t ino_index = to_le32(inode_ref->index);
 656                 uint32_t ino_gen =
 657                         to_le32(ext4_inode_get_generation(inode_ref->inode));
 658
 659                 /* Preparation: temporarily set bg checksum to 0 */
 660                 orig_checksum = ext4_inode_get_checksum(sb, inode_ref->inode);
 661                 ext4_inode_set_checksum(sb, inode_ref->inode, 0);
 662
 663                 /* First calculate crc32 checksum against fs uuid */
 664                 checksum = ext4_crc32c(~0, sb->uuid, sizeof(sb->uuid));
 665                 /* Then calculate crc32 checksum against inode number
 666                  * and inode generation */
 667                 checksum = ext4_crc32c(checksum, &ino_index,
 668                                      sizeof(ino_index));
 669                 checksum = ext4_crc32c(checksum, &ino_gen,
 670                                      sizeof(ino_gen));
 671                 /* Finally calculate crc32 checksum against
 672                  * the entire inode */
 673                 checksum = ext4_crc32c(checksum, inode_ref->inode,
 674                                 inode_size);
 675                 ext4_inode_set_checksum(sb, inode_ref->inode,
 676                                 orig_checksum);
 677         }
 678         return checksum;
 679 }
 680
 681 static void ext4_fs_set_inode_checksum(struct ext4_inode_ref *inode_ref)
 682 {
 683         struct ext4_sblock *sb = &inode_ref->fs->sb;
 684         if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 685                 return;
 686
 687         ext4_inode_set_checksum(sb, inode_ref->inode,
 688                                 ext4_fs_inode_checksum(inode_ref));
 689 }
 690
 691 int ext4_fs_get_inode_ref(struct ext4_fs *fs, uint32_t index,
 692                           struct ext4_inode_ref *ref)
 693 {
 694         /* Compute number of i-nodes, that fits in one data block */
 695         uint32_t inodes_per_group = ext4_get32(&fs->sb, inodes_per_group);
 696
 697         /*
 698          * Inode numbers are 1-based, but it is simpler to work with 0-based
 699          * when computing indices
 700          */
 701         index -= 1;
 702         uint32_t block_group = index / inodes_per_group;
 703         uint32_t offset_in_group = index % inodes_per_group;
 704
 705         /* Load block group, where i-node is located */
 706         struct ext4_block_group_ref bg_ref;
 707
 708         int rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
 709         if (rc != EOK) {
 710                 return rc;
 711         }
 712
 713         /* Load block address, where i-node table is located */
 714         uint32_t inode_table_start =
 715             ext4_bg_get_inode_table_first_block(bg_ref.block_group, &fs->sb);
 716
 717         /* Put back block group reference (not needed more) */
 718         rc = ext4_fs_put_block_group_ref(&bg_ref);
 719         if (rc != EOK) {
 720                 return rc;
 721         }
 722
 723         /* Compute position of i-node in the block group */
 724         uint16_t inode_size = ext4_get16(&fs->sb, inode_size);
 725         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
 726         uint32_t byte_offset_in_group = offset_in_group * inode_size;
 727
 728         /* Compute block address */
 729         ext4_fsblk_t block_id =
 730             inode_table_start + (byte_offset_in_group / block_size);
 731
 732         rc = ext4_block_get(fs->bdev, &ref->block, block_id);
 733         if (rc != EOK) {
 734                 return rc;
 735         }
 736
 737         /* Compute position of i-node in the data block */
 738         uint32_t offset_in_block = byte_offset_in_group % block_size;
 739         ref->inode = (struct ext4_inode *)(ref->block.data + offset_in_block);
 740
 741         /* We need to store the original value of index in the reference */
 742         ref->index = index + 1;
 743         ref->fs = fs;
 744         ref->dirty = false;
 745
 746         return EOK;
 747 }
 748
 749 int ext4_fs_put_inode_ref(struct ext4_inode_ref *ref)
 750 {
 751         /* Check if reference modified */
 752         if (ref->dirty) {
 753                 /* Mark block dirty for writing changes to physical device */
 754                 ext4_fs_set_inode_checksum(ref);
 755                 ref->block.dirty = true;
 756         }
 757
 758         /* Put back block, that contains i-node */
 759         return ext4_block_set(ref->fs->bdev, &ref->block);
 760 }
 761
 762 void ext4_fs_inode_blocks_init(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref)
 763 {
 764         int i;
 765         struct ext4_inode *inode = inode_ref->inode;
 766
 767         for (i = 0; i < EXT4_INODE_BLOCKS; i++)
 768                 inode->blocks[i] = 0;
 769
 770         (void)fs;
 771 #if CONFIG_EXTENT_ENABLE
 772         /* Initialize extents if needed */
 773         if (ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) {
 774                 ext4_inode_set_flag(inode, EXT4_INODE_FLAG_EXTENTS);
 775
 776                 /* Initialize extent root header */
 777                 ext4_extent_tree_init(inode_ref);
 778         }
 779 #endif
 780 }
 781
 782 static uint32_t ext4_fs_correspond_inode_mode(int filetype)
 783 {
 784         switch (filetype) {
 785         case EXT4_DIRENTRY_DIR:
 786                 return EXT4_INODE_MODE_DIRECTORY;
 787         case EXT4_DIRENTRY_REG_FILE:
 788                 return EXT4_INODE_MODE_FILE;
 789         case EXT4_DIRENTRY_SYMLINK:
 790                 return EXT4_INODE_MODE_SOFTLINK;
 791         default:
 792                 /* FIXME: right now we only support 3 file type. */
 793                 ext4_assert(0);
 794         }
 795         return 0;
 796 }
 797
 798 int ext4_fs_alloc_inode(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
 799                         int filetype)
 800 {
 801         /* Check if newly allocated i-node will be a directory */
 802         bool is_dir;
 803         uint16_t inode_size = ext4_get16(&fs->sb, inode_size);
 804
 805         is_dir = (filetype == EXT4_DIRENTRY_DIR);
 806
 807         /* Allocate inode by allocation algorithm */
 808         uint32_t index;
 809         int rc = ext4_ialloc_alloc_inode(fs, &index, is_dir);
 810         if (rc != EOK)
 811                 return rc;
 812
 813         /* Load i-node from on-disk i-node table */
 814         rc = ext4_fs_get_inode_ref(fs, index, inode_ref);
 815         if (rc != EOK) {
 816                 ext4_ialloc_free_inode(fs, index, is_dir);
 817                 return rc;
 818         }
 819
 820         /* Initialize i-node */
 821         struct ext4_inode *inode = inode_ref->inode;
 822
 823         uint32_t mode;
 824         if (is_dir) {
 825                 /*
 826                  * Default directory permissions to be compatible with other
 827                  * systems
 828                  * 0777 (octal) == rwxrwxrwx
 829                  */
 830
 831                 mode = 0777;
 832                 mode |= EXT4_INODE_MODE_DIRECTORY;
 833         } else {
 834                 /*
 835                  * Default file permissions to be compatible with other systems
 836                  * 0666 (octal) == rw-rw-rw-
 837                  */
 838
 839                 mode = 0666;
 840                 mode |= ext4_fs_correspond_inode_mode(filetype);
 841         }
 842         ext4_inode_set_mode(&fs->sb, inode, mode);
 843
 844         ext4_inode_set_links_count(inode, 0);
 845         ext4_inode_set_uid(inode, 0);
 846         ext4_inode_set_gid(inode, 0);
 847         ext4_inode_set_size(inode, 0);
 848         ext4_inode_set_access_time(inode, 0);
 849         ext4_inode_set_change_inode_time(inode, 0);
 850         ext4_inode_set_modification_time(inode, 0);
 851         ext4_inode_set_deletion_time(inode, 0);
 852         ext4_inode_set_blocks_count(&fs->sb, inode, 0);
 853         ext4_inode_set_flags(inode, 0);
 854         ext4_inode_set_generation(inode, 0);
 855         if (inode_size > EXT4_GOOD_OLD_INODE_SIZE)
 856                 ext4_inode_set_extra_isize(inode,
 857                                 sizeof(struct ext4_inode) -
 858                                 ext4_offsetof(struct ext4_inode,
 859                                         extra_isize));
 860
 861         /* Reset blocks array. For symbolic link inode, just
 862          * fill in blocks with 0 */
 863         if (ext4_inode_is_type(&fs->sb, inode, EXT4_INODE_MODE_SOFTLINK)) {
 864                 for (int i = 0; i < EXT4_INODE_BLOCKS; i++)
 865                         inode->blocks[i] = 0;
 866
 867         } else
 868                 ext4_fs_inode_blocks_init(fs, inode_ref);
 869
 870         inode_ref->dirty = true;
 871
 872         return EOK;
 873 }
 874
 875 int ext4_fs_free_inode(struct ext4_inode_ref *inode_ref)
 876 {
 877         struct ext4_fs *fs = inode_ref->fs;
 878         uint32_t offset;
 879         uint32_t suboff;
 880         int rc;
 881 #if CONFIG_EXTENT_ENABLE
 882         /* For extents must be data block destroyed by other way */
 883         if ((ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) &&
 884             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
 885                 /* Data structures are released during truncate operation... */
 886                 goto finish;
 887         }
 888 #endif
 889         /* Release all indirect (no data) blocks */
 890
 891         /* 1) Single indirect */
 892         ext4_fsblk_t fblock = ext4_inode_get_indirect_block(inode_ref->inode, 0);
 893         if (fblock != 0) {
 894                 int rc = ext4_balloc_free_block(inode_ref, fblock);
 895                 if (rc != EOK)
 896                         return rc;
 897
 898                 ext4_inode_set_indirect_block(inode_ref->inode, 0, 0);
 899         }
 900
 901         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
 902         uint32_t count = block_size / sizeof(uint32_t);
 903
 904         struct ext4_block block;
 905
 906         /* 2) Double indirect */
 907         fblock = ext4_inode_get_indirect_block(inode_ref->inode, 1);
 908         if (fblock != 0) {
 909                 int rc = ext4_block_get(fs->bdev, &block, fblock);
 910                 if (rc != EOK)
 911                         return rc;
 912
 913                 ext4_fsblk_t ind_block;
 914                 for (offset = 0; offset < count; ++offset) {
 915                         ind_block = to_le32(((uint32_t *)block.data)[offset]);
 916
 917                         if (ind_block == 0)
 918                                 continue;
 919                         rc = ext4_balloc_free_block(inode_ref, ind_block);
 920                         if (rc != EOK) {
 921                                 ext4_block_set(fs->bdev, &block);
 922                                 return rc;
 923                         }
 924
 925                 }
 926
 927                 ext4_block_set(fs->bdev, &block);
 928                 rc = ext4_balloc_free_block(inode_ref, fblock);
 929                 if (rc != EOK)
 930                         return rc;
 931
 932                 ext4_inode_set_indirect_block(inode_ref->inode, 1, 0);
 933         }
 934
 935         /* 3) Tripple indirect */
 936         struct ext4_block subblock;
 937         fblock = ext4_inode_get_indirect_block(inode_ref->inode, 2);
 938         if (fblock == 0)
 939                 goto finish;
 940         rc = ext4_block_get(fs->bdev, &block, fblock);
 941         if (rc != EOK)
 942                 return rc;
 943
 944         ext4_fsblk_t ind_block;
 945         for (offset = 0; offset < count; ++offset) {
 946                 ind_block = to_le32(((uint32_t *)block.data)[offset]);
 947
 948                 if (ind_block == 0)
 949                         continue;
 950                 rc = ext4_block_get(fs->bdev, &subblock,
 951                                 ind_block);
 952                 if (rc != EOK) {
 953                         ext4_block_set(fs->bdev, &block);
 954                         return rc;
 955                 }
 956
 957                 ext4_fsblk_t ind_subblk;
 958                 for (suboff = 0; suboff < count; ++suboff) {
 959                         ind_subblk = to_le32(((uint32_t *)subblock.data)[suboff]);
 960
 961                         if (ind_subblk == 0)
 962                                 continue;
 963                         rc = ext4_balloc_free_block(inode_ref, ind_subblk);
 964                         if (rc != EOK) {
 965                                 ext4_block_set(fs->bdev, &subblock);
 966                                 ext4_block_set(fs->bdev, &block);
 967                                 return rc;
 968                         }
 969
 970                 }
 971
 972                 ext4_block_set(fs->bdev, &subblock);
 973
 974                 rc = ext4_balloc_free_block(inode_ref,
 975                                 ind_block);
 976                 if (rc != EOK) {
 977                         ext4_block_set(fs->bdev, &block);
 978                         return rc;
 979                 }
 980
 981         }
 982
 983         ext4_block_set(fs->bdev, &block);
 984         rc = ext4_balloc_free_block(inode_ref, fblock);
 985         if (rc != EOK)
 986                 return rc;
 987
 988         ext4_inode_set_indirect_block(inode_ref->inode, 2, 0);
 989 finish:
 990         /* Mark inode dirty for writing to the physical device */
 991         inode_ref->dirty = true;
 992
 993         /* Free block with extended attributes if present */
 994         ext4_fsblk_t xattr_block =
 995             ext4_inode_get_file_acl(inode_ref->inode, &fs->sb);
 996         if (xattr_block) {
 997                 int rc = ext4_balloc_free_block(inode_ref, xattr_block);
 998                 if (rc != EOK)
 999                         return rc;
1000
1001                 ext4_inode_set_file_acl(inode_ref->inode, &fs->sb, 0);
1002         }
1003
1004         /* Free inode by allocator */
1005         if (ext4_inode_is_type(&fs->sb, inode_ref->inode,
1006                                EXT4_INODE_MODE_DIRECTORY))
1007                 rc = ext4_ialloc_free_inode(fs, inode_ref->index, true);
1008         else
1009                 rc = ext4_ialloc_free_inode(fs, inode_ref->index, false);
1010
1011         return rc;
1012 }
1013
1014
1015 /**@brief Release data block from i-node
1016  * @param inode_ref I-node to release block from
1017  * @param iblock    Logical block to be released
1018  * @return Error code
1019  */
1020 static int ext4_fs_release_inode_block(struct ext4_inode_ref *inode_ref,
1021                                 uint32_t iblock)
1022 {
1023         ext4_fsblk_t fblock;
1024
1025         struct ext4_fs *fs = inode_ref->fs;
1026
1027         /* Extents are handled otherwise = there is not support in this function
1028          */
1029         ext4_assert(!(
1030             ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS) &&
1031             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))));
1032
1033         struct ext4_inode *inode = inode_ref->inode;
1034
1035         /* Handle simple case when we are dealing with direct reference */
1036         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1037                 fblock = ext4_inode_get_direct_block(inode, iblock);
1038
1039                 /* Sparse file */
1040                 if (fblock == 0)
1041                         return EOK;
1042
1043                 ext4_inode_set_direct_block(inode, iblock, 0);
1044                 return ext4_balloc_free_block(inode_ref, fblock);
1045         }
1046
1047         /* Determine the indirection level needed to get the desired block */
1048         unsigned int level = 0;
1049         unsigned int i;
1050         for (i = 1; i < 4; i++) {
1051                 if (iblock < fs->inode_block_limits[i]) {
1052                         level = i;
1053                         break;
1054                 }
1055         }
1056
1057         if (level == 0)
1058                 return EIO;
1059
1060         /* Compute offsets for the topmost level */
1061         uint64_t block_offset_in_level =
1062             iblock - fs->inode_block_limits[level - 1];
1063         ext4_fsblk_t current_block =
1064             ext4_inode_get_indirect_block(inode, level - 1);
1065         uint32_t offset_in_block =
1066             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1067
1068         /*
1069          * Navigate through other levels, until we find the block number
1070          * or find null reference meaning we are dealing with sparse file
1071          */
1072         struct ext4_block block;
1073
1074         while (level > 0) {
1075
1076                 /* Sparse check */
1077                 if (current_block == 0)
1078                         return EOK;
1079
1080                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1081                 if (rc != EOK)
1082                         return rc;
1083
1084                 current_block =
1085                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1086
1087                 /* Set zero if physical data block address found */
1088                 if (level == 1) {
1089                         ((uint32_t *)block.data)[offset_in_block] = to_le32(0);
1090                         block.dirty = true;
1091                 }
1092
1093                 rc = ext4_block_set(fs->bdev, &block);
1094                 if (rc != EOK)
1095                         return rc;
1096
1097                 level--;
1098
1099                 /*
1100                  * If we are on the last level, break here as
1101                  * there is no next level to visit
1102                  */
1103                 if (level == 0)
1104                         break;
1105
1106                 /* Visit the next level */
1107                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1108                 offset_in_block = block_offset_in_level /
1109                                   fs->inode_blocks_per_level[level - 1];
1110         }
1111
1112         fblock = current_block;
1113         if (fblock == 0)
1114                 return EOK;
1115
1116         /* Physical block is not referenced, it can be released */
1117         return ext4_balloc_free_block(inode_ref, fblock);
1118 }
1119
1120 int ext4_fs_truncate_inode(struct ext4_inode_ref *inode_ref, uint64_t new_size)
1121 {
1122         struct ext4_sblock *sb = &inode_ref->fs->sb;
1123         uint32_t i;
1124
1125         /* Check flags, if i-node can be truncated */
1126         if (!ext4_inode_can_truncate(sb, inode_ref->inode))
1127                 return EINVAL;
1128
1129         /* If sizes are equal, nothing has to be done. */
1130         uint64_t old_size = ext4_inode_get_size(sb, inode_ref->inode);
1131         if (old_size == new_size)
1132                 return EOK;
1133
1134         /* It's not supported to make the larger file by truncate operation */
1135         if (old_size < new_size)
1136                 return EINVAL;
1137
1138         if (ext4_inode_is_type(sb, inode_ref->inode, EXT4_INODE_MODE_SOFTLINK)
1139                         && old_size < sizeof(inode_ref->inode->blocks)
1140                         && !ext4_inode_get_blocks_count(sb, inode_ref->inode)) {
1141                 char *content = (char *)inode_ref->inode->blocks;
1142                 memset(content + new_size, 0,
1143                         sizeof(inode_ref->inode->blocks) - new_size);
1144                 ext4_inode_set_size(inode_ref->inode, new_size);
1145                 inode_ref->dirty = true;
1146
1147                 return EOK;
1148         }
1149
1150         /* Compute how many blocks will be released */
1151         uint32_t block_size = ext4_sb_get_block_size(sb);
1152         uint32_t new_blocks_count = (new_size + block_size - 1) /
1153                                     block_size;
1154         uint32_t old_blocks_count = (old_size + block_size - 1) /
1155                                     block_size;
1156         uint32_t diff_blocks_count = old_blocks_count - new_blocks_count;
1157 #if CONFIG_EXTENT_ENABLE
1158         if ((ext4_sb_feature_incom(sb, EXT4_FINCOM_EXTENTS)) &&
1159             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1160
1161                 /* Extents require special operation */
1162                 if (diff_blocks_count) {
1163                         int rc = ext4_extent_remove_space(inode_ref,
1164                                         new_blocks_count, EXT_MAX_BLOCKS);
1165                         if (rc != EOK)
1166                                 return rc;
1167
1168                 }
1169         } else
1170 #endif
1171         {
1172                 /* Release data blocks from the end of file */
1173
1174                 /* Starting from 1 because of logical blocks are numbered from 0
1175                  */
1176                 for (i = 0; i < diff_blocks_count; ++i) {
1177                         int rc = ext4_fs_release_inode_block(
1178                             inode_ref, new_blocks_count + i);
1179                         if (rc != EOK)
1180                                 return rc;
1181                 }
1182         }
1183
1184         /* Update i-node */
1185         ext4_inode_set_size(inode_ref->inode, new_size);
1186         inode_ref->dirty = true;
1187
1188         return EOK;
1189 }
1190
1191 /**@brief Compute 'goal' for inode index
1192  * @param inode_ref Reference to inode, to allocate block for
1193  * @return goal
1194  */
1195 ext4_fsblk_t ext4_fs_inode_to_goal_block(struct ext4_inode_ref *inode_ref)
1196 {
1197         uint32_t group_inodes =
1198                 ext4_get32(&inode_ref->fs->sb, inodes_per_group);
1199         return (inode_ref->index - 1) / group_inodes;
1200 }
1201
1202 /**@brief Compute 'goal' for allocation algorithm (For blockmap).
1203  * @param inode_ref Reference to inode, to allocate block for
1204  * @param goal
1205  * @return error code
1206  */
1207 int ext4_fs_indirect_find_goal(struct ext4_inode_ref *inode_ref,
1208                                 ext4_fsblk_t *goal)
1209 {
1210         struct ext4_sblock *sb = &inode_ref->fs->sb;
1211         *goal = 0;
1212
1213         uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
1214         uint32_t block_size = ext4_sb_get_block_size(sb);
1215         uint32_t inode_block_count = inode_size / block_size;
1216
1217         if (inode_size % block_size != 0)
1218                 inode_block_count++;
1219
1220         /* If inode has some blocks, get last block address + 1 */
1221         if (inode_block_count > 0) {
1222                 int rc = ext4_fs_get_inode_data_block_index(
1223                     inode_ref, inode_block_count - 1, goal, false);
1224                 if (rc != EOK)
1225                         return rc;
1226
1227                 if (*goal != 0) {
1228                         (*goal)++;
1229                         return rc;
1230                 }
1231
1232                 /* If goal == 0, sparse file -> continue */
1233         }
1234
1235         /* Identify block group of inode */
1236
1237         uint32_t inodes_per_group = ext4_get32(sb, inodes_per_group);
1238         uint32_t block_group = (inode_ref->index - 1) / inodes_per_group;
1239         block_size = ext4_sb_get_block_size(sb);
1240
1241         /* Load block group reference */
1242         struct ext4_block_group_ref bg_ref;
1243         int rc =
1244             ext4_fs_get_block_group_ref(inode_ref->fs, block_group, &bg_ref);
1245         if (rc != EOK)
1246                 return rc;
1247
1248         /* Compute indexes */
1249         uint32_t block_group_count = ext4_block_group_cnt(sb);
1250         ext4_fsblk_t inode_table_first_block =
1251             ext4_bg_get_inode_table_first_block(bg_ref.block_group, sb);
1252         uint16_t inode_table_item_size = ext4_get16(sb, inode_size);
1253         uint32_t inode_table_bytes;
1254
1255         /* Check for last block group */
1256         if (block_group < block_group_count - 1) {
1257                 inode_table_bytes = inodes_per_group * inode_table_item_size;
1258         } else {
1259                 /* Last block group could be smaller */
1260                 uint32_t inodes_count_total = ext4_get32(sb, inodes_count);
1261
1262                 inode_table_bytes =
1263                     (inodes_count_total -
1264                      ((block_group_count - 1) * inodes_per_group)) *
1265                     inode_table_item_size;
1266         }
1267
1268         ext4_fsblk_t inode_table_blocks = inode_table_bytes / block_size;
1269
1270         if (inode_table_bytes % block_size)
1271                 inode_table_blocks++;
1272
1273         *goal = inode_table_first_block + inode_table_blocks;
1274
1275         return ext4_fs_put_block_group_ref(&bg_ref);
1276 }
1277
1278 static int ext4_fs_get_inode_data_block_idx(struct ext4_inode_ref *inode_ref,
1279                                        uint64_t iblock, ext4_fsblk_t *fblock,
1280                                        bool extent_create,
1281                                        bool support_unwritten)
1282 {
1283         struct ext4_fs *fs = inode_ref->fs;
1284
1285         /* For empty file is situation simple */
1286         if (ext4_inode_get_size(&fs->sb, inode_ref->inode) == 0) {
1287                 *fblock = 0;
1288                 return EOK;
1289         }
1290
1291         ext4_fsblk_t current_block;
1292
1293         (void)extent_create;
1294 #if CONFIG_EXTENT_ENABLE
1295         /* Handle i-node using extents */
1296         if ((ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) &&
1297             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1298
1299                 ext4_fsblk_t current_fsblk;
1300                 int rc = ext4_extent_get_blocks(inode_ref, iblock, 1,
1301                                 &current_fsblk, extent_create, NULL);
1302                 if (rc != EOK)
1303                         return rc;
1304
1305                 current_block = current_fsblk;
1306                 *fblock = current_block;
1307
1308                 ext4_assert(*fblock || support_unwritten);
1309                 return EOK;
1310         }
1311 #endif
1312
1313         struct ext4_inode *inode = inode_ref->inode;
1314
1315         /* Direct block are read directly from array in i-node structure */
1316         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1317                 current_block =
1318                     ext4_inode_get_direct_block(inode, (uint32_t)iblock);
1319                 *fblock = current_block;
1320                 return EOK;
1321         }
1322
1323         /* Determine indirection level of the target block */
1324         unsigned int level = 0;
1325         unsigned int i;
1326         for (i = 1; i < 4; i++) {
1327                 if (iblock < fs->inode_block_limits[i]) {
1328                         level = i;
1329                         break;
1330                 }
1331         }
1332
1333         if (level == 0)
1334                 return EIO;
1335
1336         /* Compute offsets for the topmost level */
1337         uint64_t block_offset_in_level =
1338             iblock - fs->inode_block_limits[level - 1];
1339         current_block = ext4_inode_get_indirect_block(inode, level - 1);
1340         uint32_t offset_in_block =
1341             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1342
1343         /* Sparse file */
1344         if (current_block == 0) {
1345                 *fblock = 0;
1346                 return EOK;
1347         }
1348
1349         struct ext4_block block;
1350
1351         /*
1352          * Navigate through other levels, until we find the block number
1353          * or find null reference meaning we are dealing with sparse file
1354          */
1355         while (level > 0) {
1356                 /* Load indirect block */
1357                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1358                 if (rc != EOK)
1359                         return rc;
1360
1361                 /* Read block address from indirect block */
1362                 current_block =
1363                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1364
1365                 /* Put back indirect block untouched */
1366                 rc = ext4_block_set(fs->bdev, &block);
1367                 if (rc != EOK)
1368                         return rc;
1369
1370                 /* Check for sparse file */
1371                 if (current_block == 0) {
1372                         *fblock = 0;
1373                         return EOK;
1374                 }
1375
1376                 /* Jump to the next level */
1377                 level--;
1378
1379                 /* Termination condition - we have address of data block loaded
1380                  */
1381                 if (level == 0)
1382                         break;
1383
1384                 /* Visit the next level */
1385                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1386                 offset_in_block = block_offset_in_level /
1387                                   fs->inode_blocks_per_level[level - 1];
1388         }
1389
1390         *fblock = current_block;
1391
1392         return EOK;
1393 }
1394
1395
1396 int ext4_fs_get_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1397                                        uint64_t iblock, ext4_fsblk_t *fblock,
1398                                        bool support_unwritten)
1399 {
1400         return ext4_fs_get_inode_data_block_idx(inode_ref, iblock, fblock,
1401                         false, support_unwritten);
1402 }
1403
1404 int ext4_fs_init_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1405                                        uint64_t iblock, ext4_fsblk_t *fblock)
1406 {
1407         return ext4_fs_get_inode_data_block_idx(inode_ref, iblock, fblock,
1408                         true, true);
1409 }
1410
1411 static int ext4_fs_set_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1412                                        uint64_t iblock, ext4_fsblk_t fblock)
1413 {
1414         struct ext4_fs *fs = inode_ref->fs;
1415
1416 #if CONFIG_EXTENT_ENABLE
1417         /* Handle inode using extents */
1418         if ((ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) &&
1419             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1420                 /* Not reachable */
1421                 return ENOTSUP;
1422         }
1423 #endif
1424
1425         /* Handle simple case when we are dealing with direct reference */
1426         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1427                 ext4_inode_set_direct_block(inode_ref->inode, (uint32_t)iblock,
1428                                             (uint32_t)fblock);
1429                 inode_ref->dirty = true;
1430
1431                 return EOK;
1432         }
1433
1434         /* Determine the indirection level needed to get the desired block */
1435         unsigned int level = 0;
1436         unsigned int i;
1437         for (i = 1; i < 4; i++) {
1438                 if (iblock < fs->inode_block_limits[i]) {
1439                         level = i;
1440                         break;
1441                 }
1442         }
1443
1444         if (level == 0)
1445                 return EIO;
1446
1447         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
1448
1449         /* Compute offsets for the topmost level */
1450         uint64_t block_offset_in_level =
1451             iblock - fs->inode_block_limits[level - 1];
1452         ext4_fsblk_t current_block =
1453             ext4_inode_get_indirect_block(inode_ref->inode, level - 1);
1454         uint32_t offset_in_block =
1455             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1456
1457         ext4_fsblk_t new_block_addr;
1458
1459         struct ext4_block block;
1460         struct ext4_block new_block;
1461
1462         /* Is needed to allocate indirect block on the i-node level */
1463         if (current_block == 0) {
1464                 /* Allocate new indirect block */
1465                 ext4_fsblk_t goal;
1466                 int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
1467                 if (rc != EOK)
1468                         return rc;
1469
1470                 rc = ext4_balloc_alloc_block(inode_ref,
1471                                              goal,
1472                                              &new_block_addr);
1473                 if (rc != EOK)
1474                         return rc;
1475
1476                 /* Update i-node */
1477                 ext4_inode_set_indirect_block(inode_ref->inode, level - 1,
1478                                               (uint32_t)new_block_addr);
1479                 inode_ref->dirty = true;
1480
1481                 /* Load newly allocated block */
1482                 rc = ext4_block_get(fs->bdev, &new_block, new_block_addr);
1483                 if (rc != EOK) {
1484                         ext4_balloc_free_block(inode_ref, new_block_addr);
1485                         return rc;
1486                 }
1487
1488                 /* Initialize new block */
1489                 memset(new_block.data, 0, block_size);
1490                 new_block.dirty = true;
1491
1492                 /* Put back the allocated block */
1493                 rc = ext4_block_set(fs->bdev, &new_block);
1494                 if (rc != EOK)
1495                         return rc;
1496
1497                 current_block = new_block_addr;
1498         }
1499
1500         /*
1501          * Navigate through other levels, until we find the block number
1502          * or find null reference meaning we are dealing with sparse file
1503          */
1504         while (level > 0) {
1505                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1506                 if (rc != EOK)
1507                         return rc;
1508
1509                 current_block =
1510                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1511
1512                 if ((level > 1) && (current_block == 0)) {
1513                         ext4_fsblk_t goal;
1514                         rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
1515                         if (rc != EOK) {
1516                                 ext4_block_set(fs->bdev, &block);
1517                                 return rc;
1518                         }
1519
1520                         /* Allocate new block */
1521                         rc =
1522                             ext4_balloc_alloc_block(inode_ref, goal, &new_block_addr);
1523                         if (rc != EOK) {
1524                                 ext4_block_set(fs->bdev, &block);
1525                                 return rc;
1526                         }
1527
1528                         /* Load newly allocated block */
1529                         rc = ext4_block_get(fs->bdev, &new_block,
1530                                             new_block_addr);
1531
1532                         if (rc != EOK) {
1533                                 ext4_block_set(fs->bdev, &block);
1534                                 return rc;
1535                         }
1536
1537                         /* Initialize allocated block */
1538                         memset(new_block.data, 0, block_size);
1539                         new_block.dirty = true;
1540
1541                         rc = ext4_block_set(fs->bdev, &new_block);
1542                         if (rc != EOK) {
1543                                 ext4_block_set(fs->bdev, &block);
1544                                 return rc;
1545                         }
1546
1547                         /* Write block address to the parent */
1548                         ((uint32_t *)block.data)[offset_in_block] =
1549                             to_le32((uint32_t)new_block_addr);
1550                         block.dirty = true;
1551                         current_block = new_block_addr;
1552                 }
1553
1554                 /* Will be finished, write the fblock address */
1555                 if (level == 1) {
1556                         ((uint32_t *)block.data)[offset_in_block] =
1557                             to_le32((uint32_t)fblock);
1558                         block.dirty = true;
1559                 }
1560
1561                 rc = ext4_block_set(fs->bdev, &block);
1562                 if (rc != EOK)
1563                         return rc;
1564
1565                 level--;
1566
1567                 /*
1568                  * If we are on the last level, break here as
1569                  * there is no next level to visit
1570                  */
1571                 if (level == 0)
1572                         break;
1573
1574                 /* Visit the next level */
1575                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1576                 offset_in_block = block_offset_in_level /
1577                                   fs->inode_blocks_per_level[level - 1];
1578         }
1579
1580         return EOK;
1581 }
1582
1583
1584 int ext4_fs_append_inode_block(struct ext4_inode_ref *inode_ref,
1585                                ext4_fsblk_t *fblock, uint32_t *iblock)
1586 {
1587 #if CONFIG_EXTENT_ENABLE
1588         /* Handle extents separately */
1589         if ((ext4_sb_feature_incom(&inode_ref->fs->sb, EXT4_FINCOM_EXTENTS)) &&
1590             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1591                 int rc;
1592                 ext4_fsblk_t current_fsblk;
1593                 struct ext4_sblock *sb = &inode_ref->fs->sb;
1594                 uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
1595                 uint32_t block_size = ext4_sb_get_block_size(sb);
1596                 *iblock = (inode_size + block_size - 1) /
1597                                     block_size;
1598
1599                 rc = ext4_extent_get_blocks(inode_ref, *iblock, 1,
1600                                 &current_fsblk, true, NULL);
1601
1602
1603                 *fblock = current_fsblk;
1604                 ext4_assert(*fblock);
1605
1606                 ext4_inode_set_size(inode_ref->inode,
1607                                     inode_size + block_size);
1608                 inode_ref->dirty = true;
1609
1610
1611                 return rc;
1612         }
1613 #endif
1614         struct ext4_sblock *sb = &inode_ref->fs->sb;
1615
1616         /* Compute next block index and allocate data block */
1617         uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
1618         uint32_t block_size = ext4_sb_get_block_size(sb);
1619
1620         /* Align size i-node size */
1621         if ((inode_size % block_size) != 0)
1622                 inode_size += block_size - (inode_size % block_size);
1623
1624         /* Logical blocks are numbered from 0 */
1625         uint32_t new_block_idx = inode_size / block_size;
1626
1627         /* Allocate new physical block */
1628         ext4_fsblk_t goal, phys_block;
1629         int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
1630         if (rc != EOK)
1631                 return rc;
1632
1633         rc = ext4_balloc_alloc_block(inode_ref, goal, &phys_block);
1634         if (rc != EOK)
1635                 return rc;
1636
1637         /* Add physical block address to the i-node */
1638         rc = ext4_fs_set_inode_data_block_index(inode_ref, new_block_idx,
1639                                                 phys_block);
1640         if (rc != EOK) {
1641                 ext4_balloc_free_block(inode_ref, phys_block);
1642                 return rc;
1643         }
1644
1645         /* Update i-node */
1646         ext4_inode_set_size(inode_ref->inode, inode_size + block_size);
1647         inode_ref->dirty = true;
1648
1649         *fblock = phys_block;
1650         *iblock = new_block_idx;
1651
1652         return EOK;
1653 }
1654
1655 void ext4_fs_inode_links_count_inc(struct ext4_inode_ref *inode_ref)
1656 {
1657         uint16_t link;
1658
1659         link = ext4_inode_get_links_count(inode_ref->inode);
1660         link++;
1661         ext4_inode_set_links_count(inode_ref->inode, link);
1662
1663         bool is_dx =
1664             ext4_sb_feature_com(&inode_ref->fs->sb, EXT4_FCOM_DIR_INDEX) &&
1665             ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_INDEX);
1666
1667         if (is_dx && link > 1) {
1668                 if (link >= EXT4_LINK_MAX || link == 2) {
1669                         ext4_inode_set_links_count(inode_ref->inode, 1);
1670
1671                         uint32_t v =
1672                             ext4_get32(&inode_ref->fs->sb, features_read_only);
1673                         v |= EXT4_FRO_COM_DIR_NLINK;
1674                         ext4_set32(&inode_ref->fs->sb, features_read_only, v);
1675                 }
1676         }
1677 }
1678
1679 void ext4_fs_inode_links_count_dec(struct ext4_inode_ref *inode_ref)
1680 {
1681         uint16_t links = ext4_inode_get_links_count(inode_ref->inode);
1682         if (!ext4_inode_is_type(&inode_ref->fs->sb, inode_ref->inode,
1683                                 EXT4_INODE_MODE_DIRECTORY)) {
1684                 if (links > 0)
1685                         ext4_inode_set_links_count(inode_ref->inode, links - 1);
1686                 return;
1687         }
1688
1689         if (links > 2)
1690                 ext4_inode_set_links_count(inode_ref->inode, links - 1);
1691 }
1692
1693 /**
1694  * @}
1695  */