lwext4/ext4_fs.c

   1 /*
   2  * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
   3  *
   4  *
   5  * HelenOS:
   6  * Copyright (c) 2012 Martin Sucha
   7  * Copyright (c) 2012 Frantisek Princ
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  *
  14  * - Redistributions of source code must retain the above copyright
  15  *   notice, this list of conditions and the following disclaimer.
  16  * - Redistributions in binary form must reproduce the above copyright
  17  *   notice, this list of conditions and the following disclaimer in the
  18  *   documentation and/or other materials provided with the distribution.
  19  * - The name of the author may not be used to endorse or promote products
  20  *   derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33 /** @addtogroup lwext4
  34  * @{
  35  */
  36 /**
  37  * @file  ext4_fs.c
  38  * @brief More complex filesystem functions.
  39  */
  40
  41 #include "ext4_config.h"
  42 #include "ext4_types.h"
  43 #include "ext4_fs.h"
  44 #include "ext4_errno.h"
  45 #include "ext4_blockdev.h"
  46 #include "ext4_super.h"
  47 #include "ext4_debug.h"
  48 #include "ext4_block_group.h"
  49 #include "ext4_balloc.h"
  50 #include "ext4_bitmap.h"
  51 #include "ext4_inode.h"
  52 #include "ext4_ialloc.h"
  53 #include "ext4_extent.h"
  54 #include "ext4_extent_full.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_FEATURE_INCOMPAT_COMPRESSION)
 132                 ext4_dbg(DEBUG_FS, DBG_NONE "compression\n");
 133         if (features_incompatible & EXT4_FEATURE_INCOMPAT_FILETYPE)
 134                 ext4_dbg(DEBUG_FS, DBG_NONE "filetype\n");
 135         if (features_incompatible & EXT4_FEATURE_INCOMPAT_RECOVER)
 136                 ext4_dbg(DEBUG_FS, DBG_NONE "recover\n");
 137         if (features_incompatible & EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)
 138                 ext4_dbg(DEBUG_FS, DBG_NONE "journal_dev\n");
 139         if (features_incompatible & EXT4_FEATURE_INCOMPAT_META_BG)
 140                 ext4_dbg(DEBUG_FS, DBG_NONE "meta_bg\n");
 141         if (features_incompatible & EXT4_FEATURE_INCOMPAT_EXTENTS)
 142                 ext4_dbg(DEBUG_FS, DBG_NONE "extents\n");
 143         if (features_incompatible & EXT4_FEATURE_INCOMPAT_64BIT)
 144                 ext4_dbg(DEBUG_FS, DBG_NONE "64bit\n");
 145         if (features_incompatible & EXT4_FEATURE_INCOMPAT_MMP)
 146                 ext4_dbg(DEBUG_FS, DBG_NONE "mnp\n");
 147         if (features_incompatible & EXT4_FEATURE_INCOMPAT_FLEX_BG)
 148                 ext4_dbg(DEBUG_FS, DBG_NONE "flex_bg\n");
 149         if (features_incompatible & EXT4_FEATURE_INCOMPAT_EA_INODE)
 150                 ext4_dbg(DEBUG_FS, DBG_NONE "ea_inode\n");
 151         if (features_incompatible & EXT4_FEATURE_INCOMPAT_DIRDATA)
 152                 ext4_dbg(DEBUG_FS, DBG_NONE "dirdata\n");
 153         if (features_incompatible & EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM)
 154                 ext4_dbg(DEBUG_FS, DBG_NONE "meta_csum\n");
 155         if (features_incompatible & EXT4_FEATURE_INCOMPAT_LARGEDIR)
 156                 ext4_dbg(DEBUG_FS, DBG_NONE "largedir\n");
 157         if (features_incompatible & EXT4_FEATURE_INCOMPAT_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_FEATURE_COMPAT_DIR_PREALLOC)
 163                 ext4_dbg(DEBUG_FS, DBG_NONE "dir_prealloc\n");
 164         if (features_compatible & EXT4_FEATURE_COMPAT_IMAGIC_INODES)
 165                 ext4_dbg(DEBUG_FS, DBG_NONE "imagic_inodes\n");
 166         if (features_compatible & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
 167                 ext4_dbg(DEBUG_FS, DBG_NONE "has_journal\n");
 168         if (features_compatible & EXT4_FEATURE_COMPAT_EXT_ATTR)
 169                 ext4_dbg(DEBUG_FS, DBG_NONE "ext_attr\n");
 170         if (features_compatible & EXT4_FEATURE_COMPAT_RESIZE_INODE)
 171                 ext4_dbg(DEBUG_FS, DBG_NONE "resize_inode\n");
 172         if (features_compatible & EXT4_FEATURE_COMPAT_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_FEATURE_RO_COMPAT_SPARSE_SUPER)
 179                 ext4_dbg(DEBUG_FS, DBG_NONE "sparse_super\n");
 180         if (features_ro & EXT4_FEATURE_RO_COMPAT_LARGE_FILE)
 181                 ext4_dbg(DEBUG_FS, DBG_NONE "large_file\n");
 182         if (features_ro & EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
 183                 ext4_dbg(DEBUG_FS, DBG_NONE "btree_dir\n");
 184         if (features_ro & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
 185                 ext4_dbg(DEBUG_FS, DBG_NONE "huge_file\n");
 186         if (features_ro & EXT4_FEATURE_RO_COMPAT_GDT_CSUM)
 187                 ext4_dbg(DEBUG_FS, DBG_NONE "gtd_csum\n");
 188         if (features_ro & EXT4_FEATURE_RO_COMPAT_DIR_NLINK)
 189                 ext4_dbg(DEBUG_FS, DBG_NONE "dir_nlink\n");
 190         if (features_ro & EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)
 191                 ext4_dbg(DEBUG_FS, DBG_NONE "extra_isize\n");
 192         if (features_ro & EXT4_FEATURE_RO_COMPAT_QUOTA)
 193                 ext4_dbg(DEBUG_FS, DBG_NONE "quota\n");
 194         if (features_ro & EXT4_FEATURE_RO_COMPAT_BIGALLOC)
 195                 ext4_dbg(DEBUG_FS, DBG_NONE "bigalloc\n");
 196         if (features_ro & EXT4_FEATURE_RO_COMPAT_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_FEATURE_INCOMPAT_SUPP));
 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_FEATURE_RO_COMPAT_SUPP));
 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                                uint32_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         uint32_t bitmap_block_addr =
 289             ext4_bg_get_block_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
 290         uint32_t bitmap_inode_addr =
 291             ext4_bg_get_inode_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
 292         uint32_t inode_table_addr =
 293             ext4_bg_get_inode_table_first_block(bg_ref->block_group,
 294                                                 &bg_ref->fs->sb);
 295         uint32_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_has_feature_incompatible(&bg_ref->fs->sb,
 304                                                  EXT4_FEATURE_INCOMPAT_FLEX_BG);
 305
 306         uint32_t inode_table_bcnt = inodes_per_group * inode_size / block_size;
 307
 308         struct ext4_block block_bitmap;
 309         int rc =
 310             ext4_block_get(bg_ref->fs->bdev, &block_bitmap, bitmap_block_addr);
 311         if (rc != EOK)
 312                 return rc;
 313
 314         memset(block_bitmap.data, 0, block_size);
 315
 316         bit_max = ext4_sb_is_super_in_bg(&bg_ref->fs->sb, bg_ref->index);
 317         if (!ext4_sb_has_feature_incompatible(&bg_ref->fs->sb,
 318                                               EXT4_FEATURE_INCOMPAT_META_BG) ||
 319                         bg_ref->index < ext4_sb_first_meta_bg(&bg_ref->fs->sb) *
 320                         dsc_per_block) {
 321                 if (bit_max) {
 322                         bit_max += ext4_bg_num_gdb(&bg_ref->fs->sb,
 323                                                    bg_ref->index);
 324                         bit_max +=
 325                                 ext4_get16(&bg_ref->fs->sb,
 326                                            s_reserved_gdt_blocks);
 327                 }
 328         } else { /* For META_BG_BLOCK_GROUPS */
 329                 bit_max += ext4_bg_num_gdb(&bg_ref->fs->sb,
 330                                            bg_ref->index);
 331         }
 332         for (bit = 0; bit < bit_max; bit++)
 333                 ext4_bmap_bit_set(block_bitmap.data, bit);
 334
 335         if (bg_ref->index == ext4_block_group_cnt(&bg_ref->fs->sb) - 1) {
 336                 /*
 337                  * Even though mke2fs always initialize first and last group
 338                  * if some other tool enabled the EXT4_BG_BLOCK_UNINIT we need
 339                  * to make sure we calculate the right free blocks
 340                  */
 341                 group_blocks = (ext4_sb_get_blocks_cnt(&bg_ref->fs->sb) -
 342                                 ext4_get32(&bg_ref->fs->sb, first_data_block) -
 343                                 (ext4_get32(&bg_ref->fs->sb, blocks_per_group) *
 344                                  (ext4_block_group_cnt(&bg_ref->fs->sb) - 1)));
 345         } else {
 346                 group_blocks = ext4_get32(&bg_ref->fs->sb, blocks_per_group);
 347         }
 348         if (!flex_bg ||
 349             ext4_block_in_group(&bg_ref->fs->sb,
 350                                 bitmap_block_addr, bg_ref->index))
 351                 ext4_bmap_bit_set(block_bitmap.data,
 352                                   bitmap_block_addr - first_group_addr);
 353
 354         if (!flex_bg ||
 355             ext4_block_in_group(&bg_ref->fs->sb,
 356                                 bitmap_inode_addr, bg_ref->index))
 357                 ext4_bmap_bit_set(block_bitmap.data,
 358                                   bitmap_inode_addr - first_group_addr);
 359
 360         for (i = inode_table_addr;
 361                 i < inode_table_addr + inode_table_bcnt; i++) {
 362                 if (!flex_bg ||
 363                     ext4_block_in_group(&bg_ref->fs->sb,
 364                                         i,
 365                                         bg_ref->index))
 366                         ext4_bmap_bit_set(block_bitmap.data,
 367                                         i - first_group_addr);
 368         }
 369         /*
 370          * Also if the number of blocks within the group is
 371          * less than the blocksize * 8 ( which is the size
 372          * of bitmap ), set rest of the block bitmap to 1
 373          */
 374         ext4_fs_mark_bitmap_end(group_blocks, block_size * 8, block_bitmap.data);
 375         block_bitmap.dirty = true;
 376
 377         /* Save bitmap */
 378         return ext4_block_set(bg_ref->fs->bdev, &block_bitmap);
 379 }
 380
 381 /**@brief Initialize i-node bitmap in block group.
 382  * @param bg_ref Reference to block group
 383  * @return Error code
 384  */
 385 static int ext4_fs_init_inode_bitmap(struct ext4_block_group_ref *bg_ref)
 386 {
 387         /* Load bitmap */
 388         uint32_t bitmap_block_addr =
 389             ext4_bg_get_inode_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
 390
 391         struct ext4_block block_bitmap;
 392         int rc =
 393             ext4_block_get(bg_ref->fs->bdev, &block_bitmap, bitmap_block_addr);
 394         if (rc != EOK)
 395                 return rc;
 396
 397         /* Initialize all bitmap bits to zero */
 398         uint32_t block_size = ext4_sb_get_block_size(&bg_ref->fs->sb);
 399         uint32_t inodes_per_group =
 400             ext4_get32(&bg_ref->fs->sb, inodes_per_group);
 401
 402         memset(block_bitmap.data, 0, (inodes_per_group + 7) / 8);
 403
 404         uint32_t start_bit = inodes_per_group;
 405         uint32_t end_bit = block_size * 8;
 406
 407         uint32_t i;
 408         for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
 409                 ext4_bmap_bit_set(block_bitmap.data, i);
 410
 411         if (i < end_bit)
 412                 memset(block_bitmap.data + (i >> 3), 0xff, (end_bit - i) >> 3);
 413
 414         block_bitmap.dirty = true;
 415
 416         /* Save bitmap */
 417         return ext4_block_set(bg_ref->fs->bdev, &block_bitmap);
 418 }
 419
 420 /**@brief Initialize i-node table in block group.
 421  * @param bg_ref Reference to block group
 422  * @return Error code
 423  */
 424 static int ext4_fs_init_inode_table(struct ext4_block_group_ref *bg_ref)
 425 {
 426         struct ext4_sblock *sb = &bg_ref->fs->sb;
 427
 428         uint32_t inode_size = ext4_get32(sb, inode_size);
 429         uint32_t block_size = ext4_sb_get_block_size(sb);
 430         uint32_t inodes_per_block = block_size / inode_size;
 431         uint32_t inodes_in_group = ext4_inodes_in_group_cnt(sb, bg_ref->index);
 432         uint32_t table_blocks = inodes_in_group / inodes_per_block;
 433         uint32_t fblock;
 434
 435         if (inodes_in_group % inodes_per_block)
 436                 table_blocks++;
 437
 438         /* Compute initialization bounds */
 439         uint32_t first_block =
 440             ext4_bg_get_inode_table_first_block(bg_ref->block_group, sb);
 441
 442         uint32_t last_block = first_block + table_blocks - 1;
 443
 444         /* Initialization of all itable blocks */
 445         for (fblock = first_block; fblock <= last_block; ++fblock) {
 446
 447                 struct ext4_block block;
 448                 int rc = ext4_block_get(bg_ref->fs->bdev, &block, fblock);
 449                 if (rc != EOK)
 450                         return rc;
 451
 452                 memset(block.data, 0, block_size);
 453                 block.dirty = true;
 454
 455                 ext4_block_set(bg_ref->fs->bdev, &block);
 456                 if (rc != EOK)
 457                         return rc;
 458         }
 459
 460         return EOK;
 461 }
 462
 463 static uint64_t ext4_fs_get_descriptor_block(struct ext4_sblock *s,
 464                                              uint32_t bgid,
 465                                              uint32_t dsc_per_block)
 466 {
 467         uint32_t first_meta_bg, dsc_id;
 468
 469         int has_super = 0;
 470
 471         dsc_id = bgid / dsc_per_block;
 472         first_meta_bg = ext4_sb_first_meta_bg(s);
 473
 474         if (!ext4_sb_has_feature_incompatible(s,
 475                                               EXT4_FEATURE_INCOMPAT_META_BG) ||
 476             dsc_id < first_meta_bg)
 477                 return ext4_get32(s, first_data_block) + dsc_id + 1;
 478
 479         if (ext4_sb_is_super_in_bg(s, bgid))
 480                 has_super = 1;
 481
 482         return (has_super + ext4_fs_first_bg_block_no(s, bgid));
 483 }
 484
 485 int ext4_fs_get_block_group_ref(struct ext4_fs *fs, uint32_t bgid,
 486                                 struct ext4_block_group_ref *ref)
 487 {
 488         /* Compute number of descriptors, that fits in one data block */
 489         uint32_t dsc_per_block =
 490             ext4_sb_get_block_size(&fs->sb) / ext4_sb_get_desc_size(&fs->sb);
 491
 492         /* Block group descriptor table starts at the next block after
 493          * superblock */
 494         uint64_t block_id =
 495             ext4_fs_get_descriptor_block(&fs->sb, bgid, dsc_per_block);
 496
 497         uint32_t offset =
 498             (bgid % dsc_per_block) * ext4_sb_get_desc_size(&fs->sb);
 499
 500         int rc = ext4_block_get(fs->bdev, &ref->block, block_id);
 501         if (rc != EOK)
 502                 return rc;
 503
 504         ref->block_group = (void *)(ref->block.data + offset);
 505         ref->fs = fs;
 506         ref->index = bgid;
 507         ref->dirty = false;
 508
 509         if (ext4_bg_has_flag(ref->block_group, EXT4_BLOCK_GROUP_BLOCK_UNINIT)) {
 510                 rc = ext4_fs_init_block_bitmap(ref);
 511                 if (rc != EOK) {
 512                         ext4_block_set(fs->bdev, &ref->block);
 513                         return rc;
 514                 }
 515                 ext4_bg_clear_flag(ref->block_group,
 516                                    EXT4_BLOCK_GROUP_BLOCK_UNINIT);
 517
 518                 ref->dirty = true;
 519         }
 520
 521         if (ext4_bg_has_flag(ref->block_group, EXT4_BLOCK_GROUP_INODE_UNINIT)) {
 522                 rc = ext4_fs_init_inode_bitmap(ref);
 523                 if (rc != EOK) {
 524                         ext4_block_set(ref->fs->bdev, &ref->block);
 525                         return rc;
 526                 }
 527
 528                 ext4_bg_clear_flag(ref->block_group,
 529                                    EXT4_BLOCK_GROUP_INODE_UNINIT);
 530
 531                 if (!ext4_bg_has_flag(ref->block_group,
 532                                       EXT4_BLOCK_GROUP_ITABLE_ZEROED)) {
 533                         rc = ext4_fs_init_inode_table(ref);
 534                         if (rc != EOK) {
 535                                 ext4_block_set(fs->bdev, &ref->block);
 536                                 return rc;
 537                         }
 538
 539                         ext4_bg_set_flag(ref->block_group,
 540                                          EXT4_BLOCK_GROUP_ITABLE_ZEROED);
 541                 }
 542
 543                 ref->dirty = true;
 544         }
 545
 546         return EOK;
 547 }
 548
 549 /**@brief  Compute checksum of block group descriptor.
 550  * @param sb   Superblock
 551  * @param bgid Index of block group in the filesystem
 552  * @param bg   Block group to compute checksum for
 553  * @return Checksum value
 554  */
 555 static uint16_t ext4_fs_bg_checksum(struct ext4_sblock *sb, uint32_t bgid,
 556                                     struct ext4_bgroup *bg)
 557 {
 558         /* If checksum not supported, 0 will be returned */
 559         uint16_t crc = 0;
 560
 561         /* Compute the checksum only if the filesystem supports it */
 562         if (ext4_sb_has_feature_read_only(sb,
 563                                           EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
 564                 uint8_t *base = (uint8_t *)bg;
 565                 uint8_t *checksum = (uint8_t *)&bg->checksum;
 566
 567                 uint32_t offset = (uint32_t)(checksum - base);
 568
 569                 /* Convert block group index to little endian */
 570                 uint32_t le_group = to_le32(bgid);
 571
 572                 /* Initialization */
 573                 crc = ext4_bg_crc16(~0, sb->uuid, sizeof(sb->uuid));
 574
 575                 /* Include index of block group */
 576                 crc =
 577                     ext4_bg_crc16(crc, (uint8_t *)&le_group, sizeof(le_group));
 578
 579                 /* Compute crc from the first part (stop before checksum field)
 580                  */
 581                 crc = ext4_bg_crc16(crc, (uint8_t *)bg, offset);
 582
 583                 /* Skip checksum */
 584                 offset += sizeof(bg->checksum);
 585
 586                 /* Checksum of the rest of block group descriptor */
 587                 if ((ext4_sb_has_feature_incompatible(
 588                         sb, EXT4_FEATURE_INCOMPAT_64BIT)) &&
 589                     (offset < ext4_sb_get_desc_size(sb)))
 590
 591                         crc = ext4_bg_crc16(crc, ((uint8_t *)bg) + offset,
 592                                             ext4_sb_get_desc_size(sb) - offset);
 593         }
 594         return crc;
 595 }
 596
 597 int ext4_fs_put_block_group_ref(struct ext4_block_group_ref *ref)
 598 {
 599         /* Check if reference modified */
 600         if (ref->dirty) {
 601                 /* Compute new checksum of block group */
 602                 uint16_t checksum = ext4_fs_bg_checksum(
 603                     &ref->fs->sb, ref->index, ref->block_group);
 604
 605                 ref->block_group->checksum = to_le16(checksum);
 606
 607                 /* Mark block dirty for writing changes to physical device */
 608                 ref->block.dirty = true;
 609         }
 610
 611         /* Put back block, that contains block group descriptor */
 612         return ext4_block_set(ref->fs->bdev, &ref->block);
 613 }
 614
 615 int ext4_fs_get_inode_ref(struct ext4_fs *fs, uint32_t index,
 616                           struct ext4_inode_ref *ref)
 617 {
 618         /* Compute number of i-nodes, that fits in one data block */
 619         uint32_t inodes_per_group = ext4_get32(&fs->sb, inodes_per_group);
 620
 621         /*
 622          * Inode numbers are 1-based, but it is simpler to work with 0-based
 623          * when computing indices
 624          */
 625         index -= 1;
 626         uint32_t block_group = index / inodes_per_group;
 627         uint32_t offset_in_group = index % inodes_per_group;
 628
 629         /* Load block group, where i-node is located */
 630         struct ext4_block_group_ref bg_ref;
 631
 632         int rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
 633         if (rc != EOK) {
 634                 return rc;
 635         }
 636
 637         /* Load block address, where i-node table is located */
 638         uint32_t inode_table_start =
 639             ext4_bg_get_inode_table_first_block(bg_ref.block_group, &fs->sb);
 640
 641         /* Put back block group reference (not needed more) */
 642         rc = ext4_fs_put_block_group_ref(&bg_ref);
 643         if (rc != EOK) {
 644                 return rc;
 645         }
 646
 647         /* Compute position of i-node in the block group */
 648         uint16_t inode_size = ext4_get16(&fs->sb, inode_size);
 649         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
 650         uint32_t byte_offset_in_group = offset_in_group * inode_size;
 651
 652         /* Compute block address */
 653         uint64_t block_id =
 654             inode_table_start + (byte_offset_in_group / block_size);
 655
 656         rc = ext4_block_get(fs->bdev, &ref->block, block_id);
 657         if (rc != EOK) {
 658                 return rc;
 659         }
 660
 661         /* Compute position of i-node in the data block */
 662         uint32_t offset_in_block = byte_offset_in_group % block_size;
 663         ref->inode = (struct ext4_inode *)(ref->block.data + offset_in_block);
 664
 665         /* We need to store the original value of index in the reference */
 666         ref->index = index + 1;
 667         ref->fs = fs;
 668         ref->dirty = false;
 669
 670         return EOK;
 671 }
 672
 673 int ext4_fs_put_inode_ref(struct ext4_inode_ref *ref)
 674 {
 675         /* Check if reference modified */
 676         if (ref->dirty) {
 677                 /* Mark block dirty for writing changes to physical device */
 678                 ref->block.dirty = true;
 679         }
 680
 681         /* Put back block, that contains i-node */
 682         return ext4_block_set(ref->fs->bdev, &ref->block);
 683 }
 684
 685 void ext4_fs_inode_blocks_init(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref)
 686 {
 687         int i;
 688         struct ext4_inode *inode = inode_ref->inode;
 689
 690         for (i = 0; i < EXT4_INODE_BLOCKS; i++)
 691                 inode->blocks[i] = 0;
 692
 693         (void)fs;
 694 #if CONFIG_EXTENT_ENABLE
 695         /* Initialize extents if needed */
 696         if (ext4_sb_has_feature_incompatible(&fs->sb,
 697                                 EXT4_FEATURE_INCOMPAT_EXTENTS)) {
 698                 ext4_inode_set_flag(inode, EXT4_INODE_FLAG_EXTENTS);
 699
 700                 /* Initialize extent root header */
 701                 ext4_ext_tree_init(inode_ref);
 702         }
 703 #endif
 704 }
 705
 706 static uint32_t ext4_fs_correspond_inode_mode(int filetype)
 707 {
 708         switch (filetype) {
 709         case EXT4_DIRENTRY_DIR:
 710                 return EXT4_INODE_MODE_DIRECTORY;
 711         case EXT4_DIRENTRY_REG_FILE:
 712                 return EXT4_INODE_MODE_FILE;
 713         case EXT4_DIRENTRY_SYMLINK:
 714                 return EXT4_INODE_MODE_SOFTLINK;
 715         default:
 716                 /* FIXME: right now we only support 3 file type. */
 717                 ext4_assert(0);
 718         }
 719         return 0;
 720 }
 721
 722 int ext4_fs_alloc_inode(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
 723                         int filetype)
 724 {
 725         /* Check if newly allocated i-node will be a directory */
 726         bool is_dir;
 727
 728         is_dir = (filetype == EXT4_DIRENTRY_DIR);
 729
 730         /* Allocate inode by allocation algorithm */
 731         uint32_t index;
 732         int rc = ext4_ialloc_alloc_inode(fs, &index, is_dir);
 733         if (rc != EOK)
 734                 return rc;
 735
 736         /* Load i-node from on-disk i-node table */
 737         rc = ext4_fs_get_inode_ref(fs, index, inode_ref);
 738         if (rc != EOK) {
 739                 ext4_ialloc_free_inode(fs, index, is_dir);
 740                 return rc;
 741         }
 742
 743         /* Initialize i-node */
 744         struct ext4_inode *inode = inode_ref->inode;
 745
 746         uint32_t mode;
 747         if (is_dir) {
 748                 /*
 749                  * Default directory permissions to be compatible with other
 750                  * systems
 751                  * 0777 (octal) == rwxrwxrwx
 752                  */
 753
 754                 mode = 0777;
 755                 mode |= EXT4_INODE_MODE_DIRECTORY;
 756         } else {
 757                 /*
 758                  * Default file permissions to be compatible with other systems
 759                  * 0666 (octal) == rw-rw-rw-
 760                  */
 761
 762                 mode = 0666;
 763                 mode |= ext4_fs_correspond_inode_mode(filetype);
 764         }
 765         ext4_inode_set_mode(&fs->sb, inode, mode);
 766
 767         ext4_inode_set_links_count(inode, 0);
 768         ext4_inode_set_uid(inode, 0);
 769         ext4_inode_set_gid(inode, 0);
 770         ext4_inode_set_size(inode, 0);
 771         ext4_inode_set_access_time(inode, 0);
 772         ext4_inode_set_change_inode_time(inode, 0);
 773         ext4_inode_set_modification_time(inode, 0);
 774         ext4_inode_set_deletion_time(inode, 0);
 775         ext4_inode_set_blocks_count(&fs->sb, inode, 0);
 776         ext4_inode_set_flags(inode, 0);
 777         ext4_inode_set_generation(inode, 0);
 778
 779         /* Reset blocks array. For symbolic link inode, just
 780          * fill in blocks with 0 */
 781         if (ext4_inode_is_type(&fs->sb, inode, EXT4_INODE_MODE_SOFTLINK)) {
 782                 for (int i = 0; i < EXT4_INODE_BLOCKS; i++)
 783                         inode->blocks[i] = 0;
 784
 785         } else
 786                 ext4_fs_inode_blocks_init(fs, inode_ref);
 787
 788         inode_ref->dirty = true;
 789
 790         return EOK;
 791 }
 792
 793 int ext4_fs_free_inode(struct ext4_inode_ref *inode_ref)
 794 {
 795         struct ext4_fs *fs = inode_ref->fs;
 796         uint32_t offset;
 797         uint32_t suboff;
 798         int rc;
 799 #if CONFIG_EXTENT_ENABLE
 800         /* For extents must be data block destroyed by other way */
 801         if ((ext4_sb_has_feature_incompatible(&fs->sb,
 802                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
 803             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
 804                 /* Data structures are released during truncate operation... */
 805                 goto finish;
 806         }
 807 #endif
 808         /* Release all indirect (no data) blocks */
 809
 810         /* 1) Single indirect */
 811         uint32_t fblock = ext4_inode_get_indirect_block(inode_ref->inode, 0);
 812         if (fblock != 0) {
 813                 int rc = ext4_balloc_free_block(inode_ref, fblock);
 814                 if (rc != EOK)
 815                         return rc;
 816
 817                 ext4_inode_set_indirect_block(inode_ref->inode, 0, 0);
 818         }
 819
 820         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
 821         uint32_t count = block_size / sizeof(uint32_t);
 822
 823         struct ext4_block block;
 824
 825         /* 2) Double indirect */
 826         fblock = ext4_inode_get_indirect_block(inode_ref->inode, 1);
 827         if (fblock != 0) {
 828                 int rc = ext4_block_get(fs->bdev, &block, fblock);
 829                 if (rc != EOK)
 830                         return rc;
 831
 832                 uint32_t ind_block;
 833                 for (offset = 0; offset < count; ++offset) {
 834                         ind_block = to_le32(((uint32_t *)block.data)[offset]);
 835
 836                         if (ind_block == 0)
 837                                 continue;
 838                         rc = ext4_balloc_free_block(inode_ref, ind_block);
 839                         if (rc != EOK) {
 840                                 ext4_block_set(fs->bdev, &block);
 841                                 return rc;
 842                         }
 843
 844                 }
 845
 846                 ext4_block_set(fs->bdev, &block);
 847                 rc = ext4_balloc_free_block(inode_ref, fblock);
 848                 if (rc != EOK)
 849                         return rc;
 850
 851                 ext4_inode_set_indirect_block(inode_ref->inode, 1, 0);
 852         }
 853
 854         /* 3) Tripple indirect */
 855         struct ext4_block subblock;
 856         fblock = ext4_inode_get_indirect_block(inode_ref->inode, 2);
 857         if (fblock == 0)
 858                 goto finish;
 859         rc = ext4_block_get(fs->bdev, &block, fblock);
 860         if (rc != EOK)
 861                 return rc;
 862
 863         uint32_t ind_block;
 864         for (offset = 0; offset < count; ++offset) {
 865                 ind_block = to_le32(((uint32_t *)block.data)[offset]);
 866
 867                 if (ind_block == 0)
 868                         continue;
 869                 rc = ext4_block_get(fs->bdev, &subblock,
 870                                 ind_block);
 871                 if (rc != EOK) {
 872                         ext4_block_set(fs->bdev, &block);
 873                         return rc;
 874                 }
 875
 876                 uint32_t ind_subblk;
 877                 for (suboff = 0; suboff < count; ++suboff) {
 878                         ind_subblk = to_le32(((uint32_t *)subblock.data)[suboff]);
 879
 880                         if (ind_subblk == 0)
 881                                 continue;
 882                         rc = ext4_balloc_free_block(inode_ref, ind_subblk);
 883                         if (rc != EOK) {
 884                                 ext4_block_set(fs->bdev, &subblock);
 885                                 ext4_block_set(fs->bdev, &block);
 886                                 return rc;
 887                         }
 888
 889                 }
 890
 891                 ext4_block_set(fs->bdev, &subblock);
 892
 893                 rc = ext4_balloc_free_block(inode_ref,
 894                                 ind_block);
 895                 if (rc != EOK) {
 896                         ext4_block_set(fs->bdev, &block);
 897                         return rc;
 898                 }
 899
 900         }
 901
 902         ext4_block_set(fs->bdev, &block);
 903         rc = ext4_balloc_free_block(inode_ref, fblock);
 904         if (rc != EOK)
 905                 return rc;
 906
 907         ext4_inode_set_indirect_block(inode_ref->inode, 2, 0);
 908 finish:
 909         /* Mark inode dirty for writing to the physical device */
 910         inode_ref->dirty = true;
 911
 912         /* Free block with extended attributes if present */
 913         uint32_t xattr_block =
 914             ext4_inode_get_file_acl(inode_ref->inode, &fs->sb);
 915         if (xattr_block) {
 916                 int rc = ext4_balloc_free_block(inode_ref, xattr_block);
 917                 if (rc != EOK)
 918                         return rc;
 919
 920                 ext4_inode_set_file_acl(inode_ref->inode, &fs->sb, 0);
 921         }
 922
 923         /* Free inode by allocator */
 924         if (ext4_inode_is_type(&fs->sb, inode_ref->inode,
 925                                EXT4_INODE_MODE_DIRECTORY))
 926                 rc = ext4_ialloc_free_inode(fs, inode_ref->index, true);
 927         else
 928                 rc = ext4_ialloc_free_inode(fs, inode_ref->index, false);
 929
 930         return rc;
 931 }
 932
 933 int ext4_fs_truncate_inode(struct ext4_inode_ref *inode_ref, uint64_t new_size)
 934 {
 935         struct ext4_sblock *sb = &inode_ref->fs->sb;
 936         uint32_t i;
 937
 938         /* Check flags, if i-node can be truncated */
 939         if (!ext4_inode_can_truncate(sb, inode_ref->inode))
 940                 return EINVAL;
 941
 942         /* If sizes are equal, nothing has to be done. */
 943         uint64_t old_size = ext4_inode_get_size(sb, inode_ref->inode);
 944         if (old_size == new_size)
 945                 return EOK;
 946
 947         /* It's not supported to make the larger file by truncate operation */
 948         if (old_size < new_size)
 949                 return EINVAL;
 950
 951         if (ext4_inode_is_type(sb, inode_ref->inode, EXT4_INODE_MODE_SOFTLINK)
 952                         && old_size < sizeof(inode_ref->inode->blocks)
 953                         && !ext4_inode_get_blocks_count(sb, inode_ref->inode)) {
 954                 char *content = (char *)inode_ref->inode->blocks;
 955                 memset(content + new_size, 0,
 956                         sizeof(inode_ref->inode->blocks) - new_size);
 957                 ext4_inode_set_size(inode_ref->inode, new_size);
 958                 inode_ref->dirty = true;
 959
 960                 return EOK;
 961         }
 962
 963         /* Compute how many blocks will be released */
 964         uint32_t block_size = ext4_sb_get_block_size(sb);
 965         uint32_t new_blocks_count = (new_size + block_size - 1) /
 966                                     block_size;
 967         uint32_t old_blocks_count = (old_size + block_size - 1) /
 968                                     block_size;
 969         uint32_t diff_blocks_count = old_blocks_count - new_blocks_count;
 970 #if CONFIG_EXTENT_ENABLE
 971         if ((ext4_sb_has_feature_incompatible(sb,
 972                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
 973             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
 974
 975                 /* Extents require special operation */
 976                 if (diff_blocks_count) {
 977                         int rc = ext4_ext_remove_space(
 978                                         inode_ref,
 979                                         new_blocks_count,
 980                                         (ext4_lblk_t)-1);
 981                         if (rc != EOK)
 982                                 return rc;
 983
 984                 }
 985         } else
 986 #endif
 987         {
 988                 /* Release data blocks from the end of file */
 989
 990                 /* Starting from 1 because of logical blocks are numbered from 0
 991                  */
 992                 for (i = 0; i < diff_blocks_count; ++i) {
 993                         int rc = ext4_fs_release_inode_block(
 994                             inode_ref, new_blocks_count + i);
 995                         if (rc != EOK)
 996                                 return rc;
 997                 }
 998         }
 999
1000         /* Update i-node */
1001         ext4_inode_set_size(inode_ref->inode, new_size);
1002         inode_ref->dirty = true;
1003
1004         return EOK;
1005 }
1006
1007 static int ext4_fs_get_inode_data_block_idx(struct ext4_inode_ref *inode_ref,
1008                                        uint64_t iblock, uint32_t *fblock,
1009                                        bool extent_create)
1010 {
1011         struct ext4_fs *fs = inode_ref->fs;
1012
1013         /* For empty file is situation simple */
1014         if (ext4_inode_get_size(&fs->sb, inode_ref->inode) == 0) {
1015                 *fblock = 0;
1016                 return EOK;
1017         }
1018
1019         uint32_t current_block;
1020
1021         (void)extent_create;
1022 #if CONFIG_EXTENT_ENABLE
1023         /* Handle i-node using extents */
1024         if ((ext4_sb_has_feature_incompatible(&fs->sb,
1025                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
1026             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1027
1028                 ext4_fsblk_t current_fsblk;
1029                 int rc = ext4_ext_get_blocks(inode_ref, iblock, 1, &current_fsblk,
1030                                         extent_create, NULL);
1031                 if (rc != EOK)
1032                         return rc;
1033
1034                 current_block = (uint32_t)current_fsblk;
1035                 *fblock = current_block;
1036
1037                 ext4_assert(*fblock);
1038                 return EOK;
1039         }
1040 #endif
1041
1042         struct ext4_inode *inode = inode_ref->inode;
1043
1044         /* Direct block are read directly from array in i-node structure */
1045         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1046                 current_block =
1047                     ext4_inode_get_direct_block(inode, (uint32_t)iblock);
1048                 *fblock = current_block;
1049                 return EOK;
1050         }
1051
1052         /* Determine indirection level of the target block */
1053         unsigned int level = 0;
1054         unsigned int i;
1055         for (i = 1; i < 4; i++) {
1056                 if (iblock < fs->inode_block_limits[i]) {
1057                         level = i;
1058                         break;
1059                 }
1060         }
1061
1062         if (level == 0)
1063                 return EIO;
1064
1065         /* Compute offsets for the topmost level */
1066         uint64_t block_offset_in_level =
1067             iblock - fs->inode_block_limits[level - 1];
1068         current_block = ext4_inode_get_indirect_block(inode, level - 1);
1069         uint32_t offset_in_block =
1070             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1071
1072         /* Sparse file */
1073         if (current_block == 0) {
1074                 *fblock = 0;
1075                 return EOK;
1076         }
1077
1078         struct ext4_block block;
1079
1080         /*
1081          * Navigate through other levels, until we find the block number
1082          * or find null reference meaning we are dealing with sparse file
1083          */
1084         while (level > 0) {
1085                 /* Load indirect block */
1086                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1087                 if (rc != EOK)
1088                         return rc;
1089
1090                 /* Read block address from indirect block */
1091                 current_block =
1092                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1093
1094                 /* Put back indirect block untouched */
1095                 rc = ext4_block_set(fs->bdev, &block);
1096                 if (rc != EOK)
1097                         return rc;
1098
1099                 /* Check for sparse file */
1100                 if (current_block == 0) {
1101                         *fblock = 0;
1102                         return EOK;
1103                 }
1104
1105                 /* Jump to the next level */
1106                 level--;
1107
1108                 /* Termination condition - we have address of data block loaded
1109                  */
1110                 if (level == 0)
1111                         break;
1112
1113                 /* Visit the next level */
1114                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1115                 offset_in_block = block_offset_in_level /
1116                                   fs->inode_blocks_per_level[level - 1];
1117         }
1118
1119         *fblock = current_block;
1120
1121         return EOK;
1122 }
1123
1124
1125 int ext4_fs_get_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1126                                        uint64_t iblock, uint32_t *fblock)
1127 {
1128         return ext4_fs_get_inode_data_block_idx(inode_ref, iblock, fblock,
1129                         false);
1130 }
1131
1132 int ext4_fs_init_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1133                                        uint64_t iblock, uint32_t *fblock)
1134 {
1135         return ext4_fs_get_inode_data_block_idx(inode_ref, iblock, fblock,
1136                         true);
1137 }
1138
1139 int ext4_fs_set_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1140                                        uint64_t iblock, uint32_t fblock)
1141 {
1142         struct ext4_fs *fs = inode_ref->fs;
1143
1144 #if CONFIG_EXTENT_ENABLE
1145         /* Handle inode using extents */
1146         if ((ext4_sb_has_feature_incompatible(&fs->sb,
1147                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
1148             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1149                 /* Not reachable */
1150                 return ENOTSUP;
1151         }
1152 #endif
1153
1154         /* Handle simple case when we are dealing with direct reference */
1155         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1156                 ext4_inode_set_direct_block(inode_ref->inode, (uint32_t)iblock,
1157                                             fblock);
1158                 inode_ref->dirty = true;
1159
1160                 return EOK;
1161         }
1162
1163         /* Determine the indirection level needed to get the desired block */
1164         unsigned int level = 0;
1165         unsigned int i;
1166         for (i = 1; i < 4; i++) {
1167                 if (iblock < fs->inode_block_limits[i]) {
1168                         level = i;
1169                         break;
1170                 }
1171         }
1172
1173         if (level == 0)
1174                 return EIO;
1175
1176         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
1177
1178         /* Compute offsets for the topmost level */
1179         uint64_t block_offset_in_level =
1180             iblock - fs->inode_block_limits[level - 1];
1181         uint32_t current_block =
1182             ext4_inode_get_indirect_block(inode_ref->inode, level - 1);
1183         uint32_t offset_in_block =
1184             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1185
1186         uint32_t new_block_addr;
1187
1188         struct ext4_block block;
1189         struct ext4_block new_block;
1190
1191         /* Is needed to allocate indirect block on the i-node level */
1192         if (current_block == 0) {
1193                 /* Allocate new indirect block */
1194                 int rc = ext4_balloc_alloc_block(inode_ref, &new_block_addr);
1195                 if (rc != EOK)
1196                         return rc;
1197
1198                 /* Update i-node */
1199                 ext4_inode_set_indirect_block(inode_ref->inode, level - 1,
1200                                               new_block_addr);
1201                 inode_ref->dirty = true;
1202
1203                 /* Load newly allocated block */
1204                 rc = ext4_block_get(fs->bdev, &new_block, new_block_addr);
1205                 if (rc != EOK) {
1206                         ext4_balloc_free_block(inode_ref, new_block_addr);
1207                         return rc;
1208                 }
1209
1210                 /* Initialize new block */
1211                 memset(new_block.data, 0, block_size);
1212                 new_block.dirty = true;
1213
1214                 /* Put back the allocated block */
1215                 rc = ext4_block_set(fs->bdev, &new_block);
1216                 if (rc != EOK)
1217                         return rc;
1218
1219                 current_block = new_block_addr;
1220         }
1221
1222         /*
1223          * Navigate through other levels, until we find the block number
1224          * or find null reference meaning we are dealing with sparse file
1225          */
1226         while (level > 0) {
1227                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1228                 if (rc != EOK)
1229                         return rc;
1230
1231                 current_block =
1232                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1233
1234                 if ((level > 1) && (current_block == 0)) {
1235                         /* Allocate new block */
1236                         rc =
1237                             ext4_balloc_alloc_block(inode_ref, &new_block_addr);
1238                         if (rc != EOK) {
1239                                 ext4_block_set(fs->bdev, &block);
1240                                 return rc;
1241                         }
1242
1243                         /* Load newly allocated block */
1244                         rc = ext4_block_get(fs->bdev, &new_block,
1245                                             new_block_addr);
1246
1247                         if (rc != EOK) {
1248                                 ext4_block_set(fs->bdev, &block);
1249                                 return rc;
1250                         }
1251
1252                         /* Initialize allocated block */
1253                         memset(new_block.data, 0, block_size);
1254                         new_block.dirty = true;
1255
1256                         rc = ext4_block_set(fs->bdev, &new_block);
1257                         if (rc != EOK) {
1258                                 ext4_block_set(fs->bdev, &block);
1259                                 return rc;
1260                         }
1261
1262                         /* Write block address to the parent */
1263                         ((uint32_t *)block.data)[offset_in_block] =
1264                             to_le32(new_block_addr);
1265                         block.dirty = true;
1266                         current_block = new_block_addr;
1267                 }
1268
1269                 /* Will be finished, write the fblock address */
1270                 if (level == 1) {
1271                         ((uint32_t *)block.data)[offset_in_block] =
1272                             to_le32(fblock);
1273                         block.dirty = true;
1274                 }
1275
1276                 rc = ext4_block_set(fs->bdev, &block);
1277                 if (rc != EOK)
1278                         return rc;
1279
1280                 level--;
1281
1282                 /*
1283                  * If we are on the last level, break here as
1284                  * there is no next level to visit
1285                  */
1286                 if (level == 0)
1287                         break;
1288
1289                 /* Visit the next level */
1290                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1291                 offset_in_block = block_offset_in_level /
1292                                   fs->inode_blocks_per_level[level - 1];
1293         }
1294
1295         return EOK;
1296 }
1297
1298 int ext4_fs_release_inode_block(struct ext4_inode_ref *inode_ref,
1299                                 uint32_t iblock)
1300 {
1301         uint32_t fblock;
1302
1303         struct ext4_fs *fs = inode_ref->fs;
1304
1305         /* Extents are handled otherwise = there is not support in this function
1306          */
1307         ext4_assert(!(
1308             ext4_sb_has_feature_incompatible(&fs->sb,
1309                                              EXT4_FEATURE_INCOMPAT_EXTENTS) &&
1310             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))));
1311
1312         struct ext4_inode *inode = inode_ref->inode;
1313
1314         /* Handle simple case when we are dealing with direct reference */
1315         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1316                 fblock = ext4_inode_get_direct_block(inode, iblock);
1317
1318                 /* Sparse file */
1319                 if (fblock == 0)
1320                         return EOK;
1321
1322                 ext4_inode_set_direct_block(inode, iblock, 0);
1323                 return ext4_balloc_free_block(inode_ref, fblock);
1324         }
1325
1326         /* Determine the indirection level needed to get the desired block */
1327         unsigned int level = 0;
1328         unsigned int i;
1329         for (i = 1; i < 4; i++) {
1330                 if (iblock < fs->inode_block_limits[i]) {
1331                         level = i;
1332                         break;
1333                 }
1334         }
1335
1336         if (level == 0)
1337                 return EIO;
1338
1339         /* Compute offsets for the topmost level */
1340         uint64_t block_offset_in_level =
1341             iblock - fs->inode_block_limits[level - 1];
1342         uint32_t current_block =
1343             ext4_inode_get_indirect_block(inode, level - 1);
1344         uint32_t offset_in_block =
1345             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1346
1347         /*
1348          * Navigate through other levels, until we find the block number
1349          * or find null reference meaning we are dealing with sparse file
1350          */
1351         struct ext4_block block;
1352
1353         while (level > 0) {
1354
1355                 /* Sparse check */
1356                 if (current_block == 0)
1357                         return EOK;
1358
1359                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1360                 if (rc != EOK)
1361                         return rc;
1362
1363                 current_block =
1364                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1365
1366                 /* Set zero if physical data block address found */
1367                 if (level == 1) {
1368                         ((uint32_t *)block.data)[offset_in_block] = to_le32(0);
1369                         block.dirty = true;
1370                 }
1371
1372                 rc = ext4_block_set(fs->bdev, &block);
1373                 if (rc != EOK)
1374                         return rc;
1375
1376                 level--;
1377
1378                 /*
1379                  * If we are on the last level, break here as
1380                  * there is no next level to visit
1381                  */
1382                 if (level == 0)
1383                         break;
1384
1385                 /* Visit the next level */
1386                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1387                 offset_in_block = block_offset_in_level /
1388                                   fs->inode_blocks_per_level[level - 1];
1389         }
1390
1391         fblock = current_block;
1392         if (fblock == 0)
1393                 return EOK;
1394
1395         /* Physical block is not referenced, it can be released */
1396         return ext4_balloc_free_block(inode_ref, fblock);
1397 }
1398
1399 int ext4_fs_append_inode_block(struct ext4_inode_ref *inode_ref,
1400                                uint32_t *fblock, uint32_t *iblock)
1401 {
1402 #if CONFIG_EXTENT_ENABLE
1403         /* Handle extents separately */
1404         if ((ext4_sb_has_feature_incompatible(&inode_ref->fs->sb,
1405                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
1406             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1407                 int rc;
1408                 ext4_fsblk_t current_fsblk;
1409                 struct ext4_sblock *sb = &inode_ref->fs->sb;
1410                 uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
1411                 uint32_t block_size = ext4_sb_get_block_size(sb);
1412                 *iblock = (inode_size + block_size - 1) /
1413                                     block_size;
1414
1415                 rc = ext4_ext_get_blocks(inode_ref, *iblock, 1, &current_fsblk,
1416                                          true, NULL);
1417
1418
1419                 *fblock = current_fsblk;
1420                 ext4_assert(*fblock);
1421
1422                 ext4_inode_set_size(inode_ref->inode,
1423                                     inode_size + block_size);
1424                 inode_ref->dirty = true;
1425
1426
1427                 return rc;
1428         }
1429 #endif
1430         struct ext4_sblock *sb = &inode_ref->fs->sb;
1431
1432         /* Compute next block index and allocate data block */
1433         uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
1434         uint32_t block_size = ext4_sb_get_block_size(sb);
1435
1436         /* Align size i-node size */
1437         if ((inode_size % block_size) != 0)
1438                 inode_size += block_size - (inode_size % block_size);
1439
1440         /* Logical blocks are numbered from 0 */
1441         uint32_t new_block_idx = inode_size / block_size;
1442
1443         /* Allocate new physical block */
1444         uint32_t phys_block;
1445         int rc = ext4_balloc_alloc_block(inode_ref, &phys_block);
1446         if (rc != EOK)
1447                 return rc;
1448
1449         /* Add physical block address to the i-node */
1450         rc = ext4_fs_set_inode_data_block_index(inode_ref, new_block_idx,
1451                                                 phys_block);
1452         if (rc != EOK) {
1453                 ext4_balloc_free_block(inode_ref, phys_block);
1454                 return rc;
1455         }
1456
1457         /* Update i-node */
1458         ext4_inode_set_size(inode_ref->inode, inode_size + block_size);
1459         inode_ref->dirty = true;
1460
1461         *fblock = phys_block;
1462         *iblock = new_block_idx;
1463
1464         return EOK;
1465 }
1466
1467 void ext4_fs_inode_links_count_inc(struct ext4_inode_ref *inode_ref)
1468 {
1469         uint16_t link;
1470
1471         link = ext4_inode_get_links_count(inode_ref->inode);
1472         link++;
1473         ext4_inode_set_links_count(inode_ref->inode, link);
1474
1475         bool is_dx =
1476             ext4_sb_has_feature_compatible(&inode_ref->fs->sb,
1477                                            EXT4_FEATURE_COMPAT_DIR_INDEX) &&
1478             ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_INDEX);
1479
1480         if (is_dx && link > 1) {
1481                 if (link >= EXT4_LINK_MAX || link == 2) {
1482                         ext4_inode_set_links_count(inode_ref->inode, 1);
1483
1484                         uint32_t v =
1485                             ext4_get32(&inode_ref->fs->sb, features_read_only);
1486                         v |= EXT4_FEATURE_RO_COMPAT_DIR_NLINK;
1487                         ext4_set32(&inode_ref->fs->sb, features_read_only, v);
1488                 }
1489         }
1490 }
1491
1492 void ext4_fs_inode_links_count_dec(struct ext4_inode_ref *inode_ref)
1493 {
1494         uint16_t links = ext4_inode_get_links_count(inode_ref->inode);
1495         if (!ext4_inode_is_type(&inode_ref->fs->sb, inode_ref->inode,
1496                                 EXT4_INODE_MODE_DIRECTORY)) {
1497                 if (links > 0)
1498                         ext4_inode_set_links_count(inode_ref->inode, links - 1);
1499                 return;
1500         }
1501
1502         if (links > 2)
1503                 ext4_inode_set_links_count(inode_ref->inode, links - 1);
1504 }
1505
1506 /**
1507  * @}
1508  */