lwext4/ext4_fs.c

   1 /*
   2  * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
   3  *
   4  *
   5  * HelenOS:
   6  * Copyright (c) 2012 Martin Sucha
   7  * Copyright (c) 2012 Frantisek Princ
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  *
  14  * - Redistributions of source code must retain the above copyright
  15  *   notice, this list of conditions and the following disclaimer.
  16  * - Redistributions in binary form must reproduce the above copyright
  17  *   notice, this list of conditions and the following disclaimer in the
  18  *   documentation and/or other materials provided with the distribution.
  19  * - The name of the author may not be used to endorse or promote products
  20  *   derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33 /** @addtogroup lwext4
  34  * @{
  35  */
  36 /**
  37  * @file  ext4_fs.c
  38  * @brief More complex filesystem functions.
  39  */
  40
  41 #include "ext4_config.h"
  42 #include "ext4_types.h"
  43 #include "ext4_fs.h"
  44 #include "ext4_errno.h"
  45 #include "ext4_blockdev.h"
  46 #include "ext4_super.h"
  47 #include "ext4_debug.h"
  48 #include "ext4_block_group.h"
  49 #include "ext4_balloc.h"
  50 #include "ext4_bitmap.h"
  51 #include "ext4_inode.h"
  52 #include "ext4_ialloc.h"
  53 #include "ext4_extent.h"
  54
  55 #include <string.h>
  56
  57 int ext4_fs_init(struct ext4_fs *fs, struct ext4_blockdev *bdev)
  58 {
  59         int r, i;
  60         uint16_t tmp;
  61         uint32_t bsize;
  62         bool read_only = false;
  63
  64         ext4_assert(fs && bdev);
  65
  66         fs->bdev = bdev;
  67
  68         r = ext4_sb_read(fs->bdev, &fs->sb);
  69         if (r != EOK)
  70                 return r;
  71
  72         if (!ext4_sb_check(&fs->sb))
  73                 return ENOTSUP;
  74
  75         bsize = ext4_sb_get_block_size(&fs->sb);
  76         if (bsize > EXT4_MAX_BLOCK_SIZE)
  77                 return ENXIO;
  78
  79         r = ext4_fs_check_features(fs, &read_only);
  80         if (r != EOK)
  81                 return r;
  82
  83         if (read_only)
  84                 return ENOTSUP;
  85
  86         /* Compute limits for indirect block levels */
  87         uint32_t blocks_id = bsize / sizeof(uint32_t);
  88
  89         fs->inode_block_limits[0] = EXT4_INODE_DIRECT_BLOCK_COUNT;
  90         fs->inode_blocks_per_level[0] = 1;
  91
  92         for (i = 1; i < 4; i++) {
  93                 fs->inode_blocks_per_level[i] =
  94                     fs->inode_blocks_per_level[i - 1] * blocks_id;
  95                 fs->inode_block_limits[i] = fs->inode_block_limits[i - 1] +
  96                                             fs->inode_blocks_per_level[i];
  97         }
  98
  99         /*Validate FS*/
 100         tmp = ext4_get16(&fs->sb, state);
 101         if (tmp & EXT4_SUPERBLOCK_STATE_ERROR_FS)
 102                 ext4_dbg(DEBUG_FS, DBG_WARN
 103                                 "last umount error: superblock fs_error flag\n");
 104
 105
 106         /* Mark system as mounted */
 107         ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_ERROR_FS);
 108         r = ext4_sb_write(fs->bdev, &fs->sb);
 109         if (r != EOK)
 110                 return r;
 111
 112         /*Update mount count*/
 113         ext4_set16(&fs->sb, mount_count, ext4_get16(&fs->sb, mount_count) + 1);
 114
 115         return r;
 116 }
 117
 118 int ext4_fs_fini(struct ext4_fs *fs)
 119 {
 120         ext4_assert(fs);
 121
 122         /*Set superblock state*/
 123         ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_VALID_FS);
 124
 125         return ext4_sb_write(fs->bdev, &fs->sb);
 126 }
 127
 128 static void ext4_fs_debug_features_inc(uint32_t features_incompatible)
 129 {
 130         if (features_incompatible & EXT4_FEATURE_INCOMPAT_COMPRESSION)
 131                 ext4_dbg(DEBUG_FS, DBG_NONE "compression\n");
 132         if (features_incompatible & EXT4_FEATURE_INCOMPAT_FILETYPE)
 133                 ext4_dbg(DEBUG_FS, DBG_NONE "filetype\n");
 134         if (features_incompatible & EXT4_FEATURE_INCOMPAT_RECOVER)
 135                 ext4_dbg(DEBUG_FS, DBG_NONE "recover\n");
 136         if (features_incompatible & EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)
 137                 ext4_dbg(DEBUG_FS, DBG_NONE "journal_dev\n");
 138         if (features_incompatible & EXT4_FEATURE_INCOMPAT_META_BG)
 139                 ext4_dbg(DEBUG_FS, DBG_NONE "meta_bg\n");
 140         if (features_incompatible & EXT4_FEATURE_INCOMPAT_EXTENTS)
 141                 ext4_dbg(DEBUG_FS, DBG_NONE "extents\n");
 142         if (features_incompatible & EXT4_FEATURE_INCOMPAT_64BIT)
 143                 ext4_dbg(DEBUG_FS, DBG_NONE "64bit\n");
 144         if (features_incompatible & EXT4_FEATURE_INCOMPAT_MMP)
 145                 ext4_dbg(DEBUG_FS, DBG_NONE "mnp\n");
 146         if (features_incompatible & EXT4_FEATURE_INCOMPAT_FLEX_BG)
 147                 ext4_dbg(DEBUG_FS, DBG_NONE "flex_bg\n");
 148         if (features_incompatible & EXT4_FEATURE_INCOMPAT_EA_INODE)
 149                 ext4_dbg(DEBUG_FS, DBG_NONE "ea_inode\n");
 150         if (features_incompatible & EXT4_FEATURE_INCOMPAT_DIRDATA)
 151                 ext4_dbg(DEBUG_FS, DBG_NONE "dirdata\n");
 152         if (features_incompatible & EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM)
 153                 ext4_dbg(DEBUG_FS, DBG_NONE "meta_csum\n");
 154         if (features_incompatible & EXT4_FEATURE_INCOMPAT_LARGEDIR)
 155                 ext4_dbg(DEBUG_FS, DBG_NONE "largedir\n");
 156         if (features_incompatible & EXT4_FEATURE_INCOMPAT_INLINE_DATA)
 157                 ext4_dbg(DEBUG_FS, DBG_NONE "inline_data\n");
 158 }
 159 static void ext4_fs_debug_features_comp(uint32_t features_compatible)
 160 {
 161         if (features_compatible & EXT4_FEATURE_COMPAT_DIR_PREALLOC)
 162                 ext4_dbg(DEBUG_FS, DBG_NONE "dir_prealloc\n");
 163         if (features_compatible & EXT4_FEATURE_COMPAT_IMAGIC_INODES)
 164                 ext4_dbg(DEBUG_FS, DBG_NONE "imagic_inodes\n");
 165         if (features_compatible & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
 166                 ext4_dbg(DEBUG_FS, DBG_NONE "has_journal\n");
 167         if (features_compatible & EXT4_FEATURE_COMPAT_EXT_ATTR)
 168                 ext4_dbg(DEBUG_FS, DBG_NONE "ext_attr\n");
 169         if (features_compatible & EXT4_FEATURE_COMPAT_RESIZE_INODE)
 170                 ext4_dbg(DEBUG_FS, DBG_NONE "resize_inode\n");
 171         if (features_compatible & EXT4_FEATURE_COMPAT_DIR_INDEX)
 172                 ext4_dbg(DEBUG_FS, DBG_NONE "dir_index\n");
 173 }
 174
 175 static void ext4_fs_debug_features_ro(uint32_t features_ro)
 176 {
 177         if (features_ro & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)
 178                 ext4_dbg(DEBUG_FS, DBG_NONE "sparse_super\n");
 179         if (features_ro & EXT4_FEATURE_RO_COMPAT_LARGE_FILE)
 180                 ext4_dbg(DEBUG_FS, DBG_NONE "large_file\n");
 181         if (features_ro & EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
 182                 ext4_dbg(DEBUG_FS, DBG_NONE "btree_dir\n");
 183         if (features_ro & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
 184                 ext4_dbg(DEBUG_FS, DBG_NONE "huge_file\n");
 185         if (features_ro & EXT4_FEATURE_RO_COMPAT_GDT_CSUM)
 186                 ext4_dbg(DEBUG_FS, DBG_NONE "gtd_csum\n");
 187         if (features_ro & EXT4_FEATURE_RO_COMPAT_DIR_NLINK)
 188                 ext4_dbg(DEBUG_FS, DBG_NONE "dir_nlink\n");
 189         if (features_ro & EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)
 190                 ext4_dbg(DEBUG_FS, DBG_NONE "extra_isize\n");
 191         if (features_ro & EXT4_FEATURE_RO_COMPAT_QUOTA)
 192                 ext4_dbg(DEBUG_FS, DBG_NONE "quota\n");
 193         if (features_ro & EXT4_FEATURE_RO_COMPAT_BIGALLOC)
 194                 ext4_dbg(DEBUG_FS, DBG_NONE "bigalloc\n");
 195         if (features_ro & EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)
 196                 ext4_dbg(DEBUG_FS, DBG_NONE "metadata_csum\n");
 197 }
 198
 199 int ext4_fs_check_features(struct ext4_fs *fs, bool *read_only)
 200 {
 201         ext4_assert(fs && read_only);
 202         uint32_t v;
 203         if (ext4_get32(&fs->sb, rev_level) == 0) {
 204                 *read_only = false;
 205                 return EOK;
 206         }
 207
 208         ext4_dbg(DEBUG_FS, DBG_INFO "sblock features_incompatible:\n");
 209         ext4_fs_debug_features_inc(ext4_get32(&fs->sb, features_incompatible));
 210
 211         ext4_dbg(DEBUG_FS, DBG_INFO "sblock features_compatible:\n");
 212         ext4_fs_debug_features_comp(ext4_get32(&fs->sb, features_compatible));
 213
 214         ext4_dbg(DEBUG_FS, DBG_INFO "sblock features_read_only:\n");
 215         ext4_fs_debug_features_ro(ext4_get32(&fs->sb, features_read_only));
 216
 217         /*Check features_incompatible*/
 218         v = (ext4_get32(&fs->sb, features_incompatible) &
 219              (~CONFIG_FEATURE_INCOMPAT_SUPP));
 220         if (v) {
 221                 ext4_dbg(DEBUG_FS, DBG_ERROR
 222                                 "sblock has unsupported features incompatible:\n");
 223                 ext4_fs_debug_features_inc(v);
 224                 return ENOTSUP;
 225         }
 226
 227         /*Check features_read_only*/
 228         v = (ext4_get32(&fs->sb, features_read_only) &
 229              (~CONFIG_FEATURE_RO_COMPAT_SUPP));
 230         if (v) {
 231                 ext4_dbg(DEBUG_FS, DBG_WARN
 232                                 "sblock has unsupported features read only:\n");
 233                 ext4_fs_debug_features_ro(v);
 234                 *read_only = true;
 235                 return EOK;
 236         }
 237         *read_only = false;
 238
 239         return EOK;
 240 }
 241
 242 /**@brief Determine whether the block is inside the group.
 243  * @param baddr   block address
 244  * @param bgid    block group id
 245  * @return Error code
 246  */
 247 static int ext4_block_in_group(struct ext4_sblock *s,
 248                                ext4_fsblk_t baddr,
 249                                uint32_t bgid)
 250 {
 251         uint32_t actual_bgid;
 252         actual_bgid = ext4_balloc_get_bgid_of_block(s, baddr);
 253         if (actual_bgid == bgid)
 254                 return 1;
 255         return 0;
 256 }
 257
 258 /**@brief   To avoid calling the atomic setbit hundreds or thousands of times, we only
 259  *          need to use it within a single byte (to ensure we get endianness right).
 260  *          We can use memset for the rest of the bitmap as there are no other users.
 261  */
 262 static void ext4_fs_mark_bitmap_end(int start_bit, int end_bit, void *bitmap)
 263 {
 264         int i;
 265
 266         if (start_bit >= end_bit)
 267                 return;
 268
 269         for (i = start_bit; (unsigned)i < ((start_bit + 7) & ~7UL); i++)
 270                 ext4_bmap_bit_set(bitmap, i);
 271
 272         if (i < end_bit)
 273                 memset((char *)bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
 274 }
 275
 276 /**@brief Initialize block bitmap in block group.
 277  * @param bg_ref Reference to block group
 278  * @return Error code
 279  */
 280 static int ext4_fs_init_block_bitmap(struct ext4_block_group_ref *bg_ref)
 281 {
 282         uint32_t i, bit, bit_max;
 283         uint32_t group_blocks;
 284         uint16_t inode_size = ext4_get16(&bg_ref->fs->sb, inode_size);
 285         uint32_t block_size = ext4_sb_get_block_size(&bg_ref->fs->sb);
 286         uint32_t inodes_per_group = ext4_get32(&bg_ref->fs->sb, inodes_per_group);
 287         ext4_fsblk_t bitmap_block_addr =
 288             ext4_bg_get_block_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
 289         ext4_fsblk_t bitmap_inode_addr =
 290             ext4_bg_get_inode_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
 291         ext4_fsblk_t inode_table_addr =
 292             ext4_bg_get_inode_table_first_block(bg_ref->block_group,
 293                                                 &bg_ref->fs->sb);
 294         ext4_fsblk_t first_group_addr =
 295             ext4_balloc_get_block_of_bgid(&bg_ref->fs->sb, bg_ref->index);
 296
 297         uint32_t dsc_per_block =
 298             ext4_sb_get_block_size(&bg_ref->fs->sb) /
 299             ext4_sb_get_desc_size(&bg_ref->fs->sb);
 300
 301         bool flex_bg =
 302                 ext4_sb_has_feature_incompatible(&bg_ref->fs->sb,
 303                                                  EXT4_FEATURE_INCOMPAT_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_has_feature_incompatible(&bg_ref->fs->sb,
 317                                               EXT4_FEATURE_INCOMPAT_META_BG) ||
 318                         bg_ref->index < ext4_sb_first_meta_bg(&bg_ref->fs->sb) *
 319                         dsc_per_block) {
 320                 if (bit_max) {
 321                         bit_max += ext4_bg_num_gdb(&bg_ref->fs->sb,
 322                                                    bg_ref->index);
 323                         bit_max +=
 324                                 ext4_get16(&bg_ref->fs->sb,
 325                                            s_reserved_gdt_blocks);
 326                 }
 327         } else { /* For META_BG_BLOCK_GROUPS */
 328                 bit_max += ext4_bg_num_gdb(&bg_ref->fs->sb,
 329                                            bg_ref->index);
 330         }
 331         for (bit = 0; bit < bit_max; bit++)
 332                 ext4_bmap_bit_set(block_bitmap.data, bit);
 333
 334         if (bg_ref->index == ext4_block_group_cnt(&bg_ref->fs->sb) - 1) {
 335                 /*
 336                  * Even though mke2fs always initialize first and last group
 337                  * if some other tool enabled the EXT4_BG_BLOCK_UNINIT we need
 338                  * to make sure we calculate the right free blocks
 339                  */
 340                 group_blocks = (ext4_sb_get_blocks_cnt(&bg_ref->fs->sb) -
 341                                 ext4_get32(&bg_ref->fs->sb, first_data_block) -
 342                                 (ext4_get32(&bg_ref->fs->sb, blocks_per_group) *
 343                                  (ext4_block_group_cnt(&bg_ref->fs->sb) - 1)));
 344         } else {
 345                 group_blocks = ext4_get32(&bg_ref->fs->sb, blocks_per_group);
 346         }
 347         if (!flex_bg ||
 348             ext4_block_in_group(&bg_ref->fs->sb,
 349                                 bitmap_block_addr, bg_ref->index))
 350                 ext4_bmap_bit_set(block_bitmap.data,
 351                                   bitmap_block_addr - first_group_addr);
 352
 353         if (!flex_bg ||
 354             ext4_block_in_group(&bg_ref->fs->sb,
 355                                 bitmap_inode_addr, bg_ref->index))
 356                 ext4_bmap_bit_set(block_bitmap.data,
 357                                   bitmap_inode_addr - first_group_addr);
 358
 359         for (i = inode_table_addr;
 360                 i < inode_table_addr + inode_table_bcnt; i++) {
 361                 if (!flex_bg ||
 362                     ext4_block_in_group(&bg_ref->fs->sb,
 363                                         i,
 364                                         bg_ref->index))
 365                         ext4_bmap_bit_set(block_bitmap.data,
 366                                         i - first_group_addr);
 367         }
 368         /*
 369          * Also if the number of blocks within the group is
 370          * less than the blocksize * 8 ( which is the size
 371          * of bitmap ), set rest of the block bitmap to 1
 372          */
 373         ext4_fs_mark_bitmap_end(group_blocks, block_size * 8, block_bitmap.data);
 374         block_bitmap.dirty = true;
 375
 376         /* Save bitmap */
 377         return ext4_block_set(bg_ref->fs->bdev, &block_bitmap);
 378 }
 379
 380 /**@brief Initialize i-node bitmap in block group.
 381  * @param bg_ref Reference to block group
 382  * @return Error code
 383  */
 384 static int ext4_fs_init_inode_bitmap(struct ext4_block_group_ref *bg_ref)
 385 {
 386         /* Load bitmap */
 387         ext4_fsblk_t bitmap_block_addr =
 388             ext4_bg_get_inode_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
 389
 390         struct ext4_block block_bitmap;
 391         int rc =
 392             ext4_block_get(bg_ref->fs->bdev, &block_bitmap, bitmap_block_addr);
 393         if (rc != EOK)
 394                 return rc;
 395
 396         /* Initialize all bitmap bits to zero */
 397         uint32_t block_size = ext4_sb_get_block_size(&bg_ref->fs->sb);
 398         uint32_t inodes_per_group =
 399             ext4_get32(&bg_ref->fs->sb, inodes_per_group);
 400
 401         memset(block_bitmap.data, 0, (inodes_per_group + 7) / 8);
 402
 403         uint32_t start_bit = inodes_per_group;
 404         uint32_t end_bit = block_size * 8;
 405
 406         uint32_t i;
 407         for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
 408                 ext4_bmap_bit_set(block_bitmap.data, i);
 409
 410         if (i < end_bit)
 411                 memset(block_bitmap.data + (i >> 3), 0xff, (end_bit - i) >> 3);
 412
 413         block_bitmap.dirty = true;
 414
 415         /* Save bitmap */
 416         return ext4_block_set(bg_ref->fs->bdev, &block_bitmap);
 417 }
 418
 419 /**@brief Initialize i-node table in block group.
 420  * @param bg_ref Reference to block group
 421  * @return Error code
 422  */
 423 static int ext4_fs_init_inode_table(struct ext4_block_group_ref *bg_ref)
 424 {
 425         struct ext4_sblock *sb = &bg_ref->fs->sb;
 426
 427         uint32_t inode_size = ext4_get32(sb, inode_size);
 428         uint32_t block_size = ext4_sb_get_block_size(sb);
 429         uint32_t inodes_per_block = block_size / inode_size;
 430         uint32_t inodes_in_group = ext4_inodes_in_group_cnt(sb, bg_ref->index);
 431         uint32_t table_blocks = inodes_in_group / inodes_per_block;
 432         ext4_fsblk_t fblock;
 433
 434         if (inodes_in_group % inodes_per_block)
 435                 table_blocks++;
 436
 437         /* Compute initialization bounds */
 438         ext4_fsblk_t first_block =
 439             ext4_bg_get_inode_table_first_block(bg_ref->block_group, sb);
 440
 441         ext4_fsblk_t last_block = first_block + table_blocks - 1;
 442
 443         /* Initialization of all itable blocks */
 444         for (fblock = first_block; fblock <= last_block; ++fblock) {
 445
 446                 struct ext4_block block;
 447                 int rc = ext4_block_get(bg_ref->fs->bdev, &block, fblock);
 448                 if (rc != EOK)
 449                         return rc;
 450
 451                 memset(block.data, 0, block_size);
 452                 block.dirty = true;
 453
 454                 ext4_block_set(bg_ref->fs->bdev, &block);
 455                 if (rc != EOK)
 456                         return rc;
 457         }
 458
 459         return EOK;
 460 }
 461
 462 static ext4_fsblk_t ext4_fs_get_descriptor_block(struct ext4_sblock *s,
 463                                              uint32_t bgid,
 464                                              uint32_t dsc_per_block)
 465 {
 466         uint32_t first_meta_bg, dsc_id;
 467
 468         int has_super = 0;
 469
 470         dsc_id = bgid / dsc_per_block;
 471         first_meta_bg = ext4_sb_first_meta_bg(s);
 472
 473         if (!ext4_sb_has_feature_incompatible(s,
 474                                               EXT4_FEATURE_INCOMPAT_META_BG) ||
 475             dsc_id < first_meta_bg)
 476                 return ext4_get32(s, first_data_block) + dsc_id + 1;
 477
 478         if (ext4_sb_is_super_in_bg(s, bgid))
 479                 has_super = 1;
 480
 481         return (has_super + ext4_fs_first_bg_block_no(s, bgid));
 482 }
 483
 484 int ext4_fs_get_block_group_ref(struct ext4_fs *fs, uint32_t bgid,
 485                                 struct ext4_block_group_ref *ref)
 486 {
 487         /* Compute number of descriptors, that fits in one data block */
 488         uint32_t dsc_per_block =
 489             ext4_sb_get_block_size(&fs->sb) / ext4_sb_get_desc_size(&fs->sb);
 490
 491         /* Block group descriptor table starts at the next block after
 492          * superblock */
 493         uint64_t block_id =
 494             ext4_fs_get_descriptor_block(&fs->sb, bgid, dsc_per_block);
 495
 496         uint32_t offset =
 497             (bgid % dsc_per_block) * ext4_sb_get_desc_size(&fs->sb);
 498
 499         int rc = ext4_block_get(fs->bdev, &ref->block, block_id);
 500         if (rc != EOK)
 501                 return rc;
 502
 503         ref->block_group = (void *)(ref->block.data + offset);
 504         ref->fs = fs;
 505         ref->index = bgid;
 506         ref->dirty = false;
 507
 508         if (ext4_bg_has_flag(ref->block_group, EXT4_BLOCK_GROUP_BLOCK_UNINIT)) {
 509                 rc = ext4_fs_init_block_bitmap(ref);
 510                 if (rc != EOK) {
 511                         ext4_block_set(fs->bdev, &ref->block);
 512                         return rc;
 513                 }
 514                 ext4_bg_clear_flag(ref->block_group,
 515                                    EXT4_BLOCK_GROUP_BLOCK_UNINIT);
 516
 517                 ref->dirty = true;
 518         }
 519
 520         if (ext4_bg_has_flag(ref->block_group, EXT4_BLOCK_GROUP_INODE_UNINIT)) {
 521                 rc = ext4_fs_init_inode_bitmap(ref);
 522                 if (rc != EOK) {
 523                         ext4_block_set(ref->fs->bdev, &ref->block);
 524                         return rc;
 525                 }
 526
 527                 ext4_bg_clear_flag(ref->block_group,
 528                                    EXT4_BLOCK_GROUP_INODE_UNINIT);
 529
 530                 if (!ext4_bg_has_flag(ref->block_group,
 531                                       EXT4_BLOCK_GROUP_ITABLE_ZEROED)) {
 532                         rc = ext4_fs_init_inode_table(ref);
 533                         if (rc != EOK) {
 534                                 ext4_block_set(fs->bdev, &ref->block);
 535                                 return rc;
 536                         }
 537
 538                         ext4_bg_set_flag(ref->block_group,
 539                                          EXT4_BLOCK_GROUP_ITABLE_ZEROED);
 540                 }
 541
 542                 ref->dirty = true;
 543         }
 544
 545         return EOK;
 546 }
 547
 548 /**@brief  Compute checksum of block group descriptor.
 549  * @param sb   Superblock
 550  * @param bgid Index of block group in the filesystem
 551  * @param bg   Block group to compute checksum for
 552  * @return Checksum value
 553  */
 554 static uint16_t ext4_fs_bg_checksum(struct ext4_sblock *sb, uint32_t bgid,
 555                                     struct ext4_bgroup *bg)
 556 {
 557         /* If checksum not supported, 0 will be returned */
 558         uint16_t crc = 0;
 559
 560         /* Compute the checksum only if the filesystem supports it */
 561         if (ext4_sb_has_feature_read_only(sb,
 562                                           EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
 563                 uint8_t *base = (uint8_t *)bg;
 564                 uint8_t *checksum = (uint8_t *)&bg->checksum;
 565
 566                 uint32_t offset = (uint32_t)(checksum - base);
 567
 568                 /* Convert block group index to little endian */
 569                 uint32_t le_group = to_le32(bgid);
 570
 571                 /* Initialization */
 572                 crc = ext4_bg_crc16(~0, sb->uuid, sizeof(sb->uuid));
 573
 574                 /* Include index of block group */
 575                 crc =
 576                     ext4_bg_crc16(crc, (uint8_t *)&le_group, sizeof(le_group));
 577
 578                 /* Compute crc from the first part (stop before checksum field)
 579                  */
 580                 crc = ext4_bg_crc16(crc, (uint8_t *)bg, offset);
 581
 582                 /* Skip checksum */
 583                 offset += sizeof(bg->checksum);
 584
 585                 /* Checksum of the rest of block group descriptor */
 586                 if ((ext4_sb_has_feature_incompatible(
 587                         sb, EXT4_FEATURE_INCOMPAT_64BIT)) &&
 588                     (offset < ext4_sb_get_desc_size(sb)))
 589
 590                         crc = ext4_bg_crc16(crc, ((uint8_t *)bg) + offset,
 591                                             ext4_sb_get_desc_size(sb) - offset);
 592         }
 593         return crc;
 594 }
 595
 596 int ext4_fs_put_block_group_ref(struct ext4_block_group_ref *ref)
 597 {
 598         /* Check if reference modified */
 599         if (ref->dirty) {
 600                 /* Compute new checksum of block group */
 601                 uint16_t checksum = ext4_fs_bg_checksum(
 602                     &ref->fs->sb, ref->index, ref->block_group);
 603
 604                 ref->block_group->checksum = to_le16(checksum);
 605
 606                 /* Mark block dirty for writing changes to physical device */
 607                 ref->block.dirty = true;
 608         }
 609
 610         /* Put back block, that contains block group descriptor */
 611         return ext4_block_set(ref->fs->bdev, &ref->block);
 612 }
 613
 614 int ext4_fs_get_inode_ref(struct ext4_fs *fs, uint32_t index,
 615                           struct ext4_inode_ref *ref)
 616 {
 617         /* Compute number of i-nodes, that fits in one data block */
 618         uint32_t inodes_per_group = ext4_get32(&fs->sb, inodes_per_group);
 619
 620         /*
 621          * Inode numbers are 1-based, but it is simpler to work with 0-based
 622          * when computing indices
 623          */
 624         index -= 1;
 625         uint32_t block_group = index / inodes_per_group;
 626         uint32_t offset_in_group = index % inodes_per_group;
 627
 628         /* Load block group, where i-node is located */
 629         struct ext4_block_group_ref bg_ref;
 630
 631         int rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
 632         if (rc != EOK) {
 633                 return rc;
 634         }
 635
 636         /* Load block address, where i-node table is located */
 637         uint32_t inode_table_start =
 638             ext4_bg_get_inode_table_first_block(bg_ref.block_group, &fs->sb);
 639
 640         /* Put back block group reference (not needed more) */
 641         rc = ext4_fs_put_block_group_ref(&bg_ref);
 642         if (rc != EOK) {
 643                 return rc;
 644         }
 645
 646         /* Compute position of i-node in the block group */
 647         uint16_t inode_size = ext4_get16(&fs->sb, inode_size);
 648         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
 649         uint32_t byte_offset_in_group = offset_in_group * inode_size;
 650
 651         /* Compute block address */
 652         ext4_fsblk_t block_id =
 653             inode_table_start + (byte_offset_in_group / block_size);
 654
 655         rc = ext4_block_get(fs->bdev, &ref->block, block_id);
 656         if (rc != EOK) {
 657                 return rc;
 658         }
 659
 660         /* Compute position of i-node in the data block */
 661         uint32_t offset_in_block = byte_offset_in_group % block_size;
 662         ref->inode = (struct ext4_inode *)(ref->block.data + offset_in_block);
 663
 664         /* We need to store the original value of index in the reference */
 665         ref->index = index + 1;
 666         ref->fs = fs;
 667         ref->dirty = false;
 668
 669         return EOK;
 670 }
 671
 672 int ext4_fs_put_inode_ref(struct ext4_inode_ref *ref)
 673 {
 674         /* Check if reference modified */
 675         if (ref->dirty) {
 676                 /* Mark block dirty for writing changes to physical device */
 677                 ref->block.dirty = true;
 678         }
 679
 680         /* Put back block, that contains i-node */
 681         return ext4_block_set(ref->fs->bdev, &ref->block);
 682 }
 683
 684 void ext4_fs_inode_blocks_init(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref)
 685 {
 686         int i;
 687         struct ext4_inode *inode = inode_ref->inode;
 688
 689         for (i = 0; i < EXT4_INODE_BLOCKS; i++)
 690                 inode->blocks[i] = 0;
 691
 692         (void)fs;
 693 #if CONFIG_EXTENT_ENABLE
 694         /* Initialize extents if needed */
 695         if (ext4_sb_has_feature_incompatible(&fs->sb,
 696                                 EXT4_FEATURE_INCOMPAT_EXTENTS)) {
 697                 ext4_inode_set_flag(inode, EXT4_INODE_FLAG_EXTENTS);
 698
 699                 /* Initialize extent root header */
 700                 ext4_extent_tree_init(inode_ref);
 701         }
 702 #endif
 703 }
 704
 705 static uint32_t ext4_fs_correspond_inode_mode(int filetype)
 706 {
 707         switch (filetype) {
 708         case EXT4_DIRENTRY_DIR:
 709                 return EXT4_INODE_MODE_DIRECTORY;
 710         case EXT4_DIRENTRY_REG_FILE:
 711                 return EXT4_INODE_MODE_FILE;
 712         case EXT4_DIRENTRY_SYMLINK:
 713                 return EXT4_INODE_MODE_SOFTLINK;
 714         default:
 715                 /* FIXME: right now we only support 3 file type. */
 716                 ext4_assert(0);
 717         }
 718         return 0;
 719 }
 720
 721 int ext4_fs_alloc_inode(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
 722                         int filetype)
 723 {
 724         /* Check if newly allocated i-node will be a directory */
 725         bool is_dir;
 726
 727         is_dir = (filetype == EXT4_DIRENTRY_DIR);
 728
 729         /* Allocate inode by allocation algorithm */
 730         uint32_t index;
 731         int rc = ext4_ialloc_alloc_inode(fs, &index, is_dir);
 732         if (rc != EOK)
 733                 return rc;
 734
 735         /* Load i-node from on-disk i-node table */
 736         rc = ext4_fs_get_inode_ref(fs, index, inode_ref);
 737         if (rc != EOK) {
 738                 ext4_ialloc_free_inode(fs, index, is_dir);
 739                 return rc;
 740         }
 741
 742         /* Initialize i-node */
 743         struct ext4_inode *inode = inode_ref->inode;
 744
 745         uint32_t mode;
 746         if (is_dir) {
 747                 /*
 748                  * Default directory permissions to be compatible with other
 749                  * systems
 750                  * 0777 (octal) == rwxrwxrwx
 751                  */
 752
 753                 mode = 0777;
 754                 mode |= EXT4_INODE_MODE_DIRECTORY;
 755         } else {
 756                 /*
 757                  * Default file permissions to be compatible with other systems
 758                  * 0666 (octal) == rw-rw-rw-
 759                  */
 760
 761                 mode = 0666;
 762                 mode |= ext4_fs_correspond_inode_mode(filetype);
 763         }
 764         ext4_inode_set_mode(&fs->sb, inode, mode);
 765
 766         ext4_inode_set_links_count(inode, 0);
 767         ext4_inode_set_uid(inode, 0);
 768         ext4_inode_set_gid(inode, 0);
 769         ext4_inode_set_size(inode, 0);
 770         ext4_inode_set_access_time(inode, 0);
 771         ext4_inode_set_change_inode_time(inode, 0);
 772         ext4_inode_set_modification_time(inode, 0);
 773         ext4_inode_set_deletion_time(inode, 0);
 774         ext4_inode_set_blocks_count(&fs->sb, inode, 0);
 775         ext4_inode_set_flags(inode, 0);
 776         ext4_inode_set_generation(inode, 0);
 777
 778         /* Reset blocks array. For symbolic link inode, just
 779          * fill in blocks with 0 */
 780         if (ext4_inode_is_type(&fs->sb, inode, EXT4_INODE_MODE_SOFTLINK)) {
 781                 for (int i = 0; i < EXT4_INODE_BLOCKS; i++)
 782                         inode->blocks[i] = 0;
 783
 784         } else
 785                 ext4_fs_inode_blocks_init(fs, inode_ref);
 786
 787         inode_ref->dirty = true;
 788
 789         return EOK;
 790 }
 791
 792 int ext4_fs_free_inode(struct ext4_inode_ref *inode_ref)
 793 {
 794         struct ext4_fs *fs = inode_ref->fs;
 795         uint32_t offset;
 796         uint32_t suboff;
 797         int rc;
 798 #if CONFIG_EXTENT_ENABLE
 799         /* For extents must be data block destroyed by other way */
 800         if ((ext4_sb_has_feature_incompatible(&fs->sb,
 801                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
 802             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
 803                 /* Data structures are released during truncate operation... */
 804                 goto finish;
 805         }
 806 #endif
 807         /* Release all indirect (no data) blocks */
 808
 809         /* 1) Single indirect */
 810         ext4_fsblk_t fblock = ext4_inode_get_indirect_block(inode_ref->inode, 0);
 811         if (fblock != 0) {
 812                 int rc = ext4_balloc_free_block(inode_ref, fblock);
 813                 if (rc != EOK)
 814                         return rc;
 815
 816                 ext4_inode_set_indirect_block(inode_ref->inode, 0, 0);
 817         }
 818
 819         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
 820         uint32_t count = block_size / sizeof(uint32_t);
 821
 822         struct ext4_block block;
 823
 824         /* 2) Double indirect */
 825         fblock = ext4_inode_get_indirect_block(inode_ref->inode, 1);
 826         if (fblock != 0) {
 827                 int rc = ext4_block_get(fs->bdev, &block, fblock);
 828                 if (rc != EOK)
 829                         return rc;
 830
 831                 ext4_fsblk_t ind_block;
 832                 for (offset = 0; offset < count; ++offset) {
 833                         ind_block = to_le32(((uint32_t *)block.data)[offset]);
 834
 835                         if (ind_block == 0)
 836                                 continue;
 837                         rc = ext4_balloc_free_block(inode_ref, ind_block);
 838                         if (rc != EOK) {
 839                                 ext4_block_set(fs->bdev, &block);
 840                                 return rc;
 841                         }
 842
 843                 }
 844
 845                 ext4_block_set(fs->bdev, &block);
 846                 rc = ext4_balloc_free_block(inode_ref, fblock);
 847                 if (rc != EOK)
 848                         return rc;
 849
 850                 ext4_inode_set_indirect_block(inode_ref->inode, 1, 0);
 851         }
 852
 853         /* 3) Tripple indirect */
 854         struct ext4_block subblock;
 855         fblock = ext4_inode_get_indirect_block(inode_ref->inode, 2);
 856         if (fblock == 0)
 857                 goto finish;
 858         rc = ext4_block_get(fs->bdev, &block, fblock);
 859         if (rc != EOK)
 860                 return rc;
 861
 862         ext4_fsblk_t ind_block;
 863         for (offset = 0; offset < count; ++offset) {
 864                 ind_block = to_le32(((uint32_t *)block.data)[offset]);
 865
 866                 if (ind_block == 0)
 867                         continue;
 868                 rc = ext4_block_get(fs->bdev, &subblock,
 869                                 ind_block);
 870                 if (rc != EOK) {
 871                         ext4_block_set(fs->bdev, &block);
 872                         return rc;
 873                 }
 874
 875                 ext4_fsblk_t ind_subblk;
 876                 for (suboff = 0; suboff < count; ++suboff) {
 877                         ind_subblk = to_le32(((uint32_t *)subblock.data)[suboff]);
 878
 879                         if (ind_subblk == 0)
 880                                 continue;
 881                         rc = ext4_balloc_free_block(inode_ref, ind_subblk);
 882                         if (rc != EOK) {
 883                                 ext4_block_set(fs->bdev, &subblock);
 884                                 ext4_block_set(fs->bdev, &block);
 885                                 return rc;
 886                         }
 887
 888                 }
 889
 890                 ext4_block_set(fs->bdev, &subblock);
 891
 892                 rc = ext4_balloc_free_block(inode_ref,
 893                                 ind_block);
 894                 if (rc != EOK) {
 895                         ext4_block_set(fs->bdev, &block);
 896                         return rc;
 897                 }
 898
 899         }
 900
 901         ext4_block_set(fs->bdev, &block);
 902         rc = ext4_balloc_free_block(inode_ref, fblock);
 903         if (rc != EOK)
 904                 return rc;
 905
 906         ext4_inode_set_indirect_block(inode_ref->inode, 2, 0);
 907 finish:
 908         /* Mark inode dirty for writing to the physical device */
 909         inode_ref->dirty = true;
 910
 911         /* Free block with extended attributes if present */
 912         ext4_fsblk_t xattr_block =
 913             ext4_inode_get_file_acl(inode_ref->inode, &fs->sb);
 914         if (xattr_block) {
 915                 int rc = ext4_balloc_free_block(inode_ref, xattr_block);
 916                 if (rc != EOK)
 917                         return rc;
 918
 919                 ext4_inode_set_file_acl(inode_ref->inode, &fs->sb, 0);
 920         }
 921
 922         /* Free inode by allocator */
 923         if (ext4_inode_is_type(&fs->sb, inode_ref->inode,
 924                                EXT4_INODE_MODE_DIRECTORY))
 925                 rc = ext4_ialloc_free_inode(fs, inode_ref->index, true);
 926         else
 927                 rc = ext4_ialloc_free_inode(fs, inode_ref->index, false);
 928
 929         return rc;
 930 }
 931
 932 int ext4_fs_truncate_inode(struct ext4_inode_ref *inode_ref, uint64_t new_size)
 933 {
 934         struct ext4_sblock *sb = &inode_ref->fs->sb;
 935         uint32_t i;
 936
 937         /* Check flags, if i-node can be truncated */
 938         if (!ext4_inode_can_truncate(sb, inode_ref->inode))
 939                 return EINVAL;
 940
 941         /* If sizes are equal, nothing has to be done. */
 942         uint64_t old_size = ext4_inode_get_size(sb, inode_ref->inode);
 943         if (old_size == new_size)
 944                 return EOK;
 945
 946         /* It's not supported to make the larger file by truncate operation */
 947         if (old_size < new_size)
 948                 return EINVAL;
 949
 950         if (ext4_inode_is_type(sb, inode_ref->inode, EXT4_INODE_MODE_SOFTLINK)
 951                         && old_size < sizeof(inode_ref->inode->blocks)
 952                         && !ext4_inode_get_blocks_count(sb, inode_ref->inode)) {
 953                 char *content = (char *)inode_ref->inode->blocks;
 954                 memset(content + new_size, 0,
 955                         sizeof(inode_ref->inode->blocks) - new_size);
 956                 ext4_inode_set_size(inode_ref->inode, new_size);
 957                 inode_ref->dirty = true;
 958
 959                 return EOK;
 960         }
 961
 962         /* Compute how many blocks will be released */
 963         uint32_t block_size = ext4_sb_get_block_size(sb);
 964         uint32_t new_blocks_count = (new_size + block_size - 1) /
 965                                     block_size;
 966         uint32_t old_blocks_count = (old_size + block_size - 1) /
 967                                     block_size;
 968         uint32_t diff_blocks_count = old_blocks_count - new_blocks_count;
 969 #if CONFIG_EXTENT_ENABLE
 970         if ((ext4_sb_has_feature_incompatible(sb,
 971                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
 972             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
 973
 974                 /* Extents require special operation */
 975                 if (diff_blocks_count) {
 976                         int rc = ext4_extent_remove_space(inode_ref,
 977                                         new_blocks_count, EXT_MAX_BLOCKS);
 978                         if (rc != EOK)
 979                                 return rc;
 980
 981                 }
 982         } else
 983 #endif
 984         {
 985                 /* Release data blocks from the end of file */
 986
 987                 /* Starting from 1 because of logical blocks are numbered from 0
 988                  */
 989                 for (i = 0; i < diff_blocks_count; ++i) {
 990                         int rc = ext4_fs_release_inode_block(
 991                             inode_ref, new_blocks_count + i);
 992                         if (rc != EOK)
 993                                 return rc;
 994                 }
 995         }
 996
 997         /* Update i-node */
 998         ext4_inode_set_size(inode_ref->inode, new_size);
 999         inode_ref->dirty = true;
1000
1001         return EOK;
1002 }
1003
1004 /**@brief Compute 'goal' for inode index
1005  * @param inode_ref Reference to inode, to allocate block for
1006  * @return goal
1007  */
1008 ext4_fsblk_t ext4_fs_inode_to_goal_block(struct ext4_inode_ref *inode_ref)
1009 {
1010         uint32_t group_inodes =
1011                 ext4_get32(&inode_ref->fs->sb, inodes_per_group);
1012         return (inode_ref->index - 1) / group_inodes;
1013 }
1014
1015 /**@brief Compute 'goal' for allocation algorithm (For blockmap).
1016  * @param inode_ref Reference to inode, to allocate block for
1017  * @param goal
1018  * @return error code
1019  */
1020 int ext4_fs_indirect_find_goal(struct ext4_inode_ref *inode_ref,
1021                                 ext4_fsblk_t *goal)
1022 {
1023         struct ext4_sblock *sb = &inode_ref->fs->sb;
1024         *goal = 0;
1025
1026         uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
1027         uint32_t block_size = ext4_sb_get_block_size(sb);
1028         uint32_t inode_block_count = inode_size / block_size;
1029
1030         if (inode_size % block_size != 0)
1031                 inode_block_count++;
1032
1033         /* If inode has some blocks, get last block address + 1 */
1034         if (inode_block_count > 0) {
1035                 int rc = ext4_fs_get_inode_data_block_index(
1036                     inode_ref, inode_block_count - 1, goal, false);
1037                 if (rc != EOK)
1038                         return rc;
1039
1040                 if (*goal != 0) {
1041                         (*goal)++;
1042                         return rc;
1043                 }
1044
1045                 /* If goal == 0, sparse file -> continue */
1046         }
1047
1048         /* Identify block group of inode */
1049
1050         uint32_t inodes_per_group = ext4_get32(sb, inodes_per_group);
1051         uint32_t block_group = (inode_ref->index - 1) / inodes_per_group;
1052         block_size = ext4_sb_get_block_size(sb);
1053
1054         /* Load block group reference */
1055         struct ext4_block_group_ref bg_ref;
1056         int rc =
1057             ext4_fs_get_block_group_ref(inode_ref->fs, block_group, &bg_ref);
1058         if (rc != EOK)
1059                 return rc;
1060
1061         /* Compute indexes */
1062         uint32_t block_group_count = ext4_block_group_cnt(sb);
1063         ext4_fsblk_t inode_table_first_block =
1064             ext4_bg_get_inode_table_first_block(bg_ref.block_group, sb);
1065         uint16_t inode_table_item_size = ext4_get16(sb, inode_size);
1066         uint32_t inode_table_bytes;
1067
1068         /* Check for last block group */
1069         if (block_group < block_group_count - 1) {
1070                 inode_table_bytes = inodes_per_group * inode_table_item_size;
1071         } else {
1072                 /* Last block group could be smaller */
1073                 uint32_t inodes_count_total = ext4_get32(sb, inodes_count);
1074
1075                 inode_table_bytes =
1076                     (inodes_count_total -
1077                      ((block_group_count - 1) * inodes_per_group)) *
1078                     inode_table_item_size;
1079         }
1080
1081         ext4_fsblk_t inode_table_blocks = inode_table_bytes / block_size;
1082
1083         if (inode_table_bytes % block_size)
1084                 inode_table_blocks++;
1085
1086         *goal = inode_table_first_block + inode_table_blocks;
1087
1088         return ext4_fs_put_block_group_ref(&bg_ref);
1089 }
1090
1091 static int ext4_fs_get_inode_data_block_idx(struct ext4_inode_ref *inode_ref,
1092                                        uint64_t iblock, ext4_fsblk_t *fblock,
1093                                        bool extent_create,
1094                                        bool support_unwritten)
1095 {
1096         struct ext4_fs *fs = inode_ref->fs;
1097
1098         /* For empty file is situation simple */
1099         if (ext4_inode_get_size(&fs->sb, inode_ref->inode) == 0) {
1100                 *fblock = 0;
1101                 return EOK;
1102         }
1103
1104         ext4_fsblk_t current_block;
1105
1106         (void)extent_create;
1107 #if CONFIG_EXTENT_ENABLE
1108         /* Handle i-node using extents */
1109         if ((ext4_sb_has_feature_incompatible(&fs->sb,
1110                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
1111             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1112
1113                 ext4_fsblk_t current_fsblk;
1114                 int rc = ext4_extent_get_blocks(inode_ref, iblock, 1,
1115                                 &current_fsblk, extent_create, NULL);
1116                 if (rc != EOK)
1117                         return rc;
1118
1119                 current_block = current_fsblk;
1120                 *fblock = current_block;
1121
1122                 ext4_assert(*fblock || support_unwritten);
1123                 return EOK;
1124         }
1125 #endif
1126
1127         struct ext4_inode *inode = inode_ref->inode;
1128
1129         /* Direct block are read directly from array in i-node structure */
1130         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1131                 current_block =
1132                     ext4_inode_get_direct_block(inode, (uint32_t)iblock);
1133                 *fblock = current_block;
1134                 return EOK;
1135         }
1136
1137         /* Determine indirection level of the target block */
1138         unsigned int level = 0;
1139         unsigned int i;
1140         for (i = 1; i < 4; i++) {
1141                 if (iblock < fs->inode_block_limits[i]) {
1142                         level = i;
1143                         break;
1144                 }
1145         }
1146
1147         if (level == 0)
1148                 return EIO;
1149
1150         /* Compute offsets for the topmost level */
1151         uint64_t block_offset_in_level =
1152             iblock - fs->inode_block_limits[level - 1];
1153         current_block = ext4_inode_get_indirect_block(inode, level - 1);
1154         uint32_t offset_in_block =
1155             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1156
1157         /* Sparse file */
1158         if (current_block == 0) {
1159                 *fblock = 0;
1160                 return EOK;
1161         }
1162
1163         struct ext4_block block;
1164
1165         /*
1166          * Navigate through other levels, until we find the block number
1167          * or find null reference meaning we are dealing with sparse file
1168          */
1169         while (level > 0) {
1170                 /* Load indirect block */
1171                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1172                 if (rc != EOK)
1173                         return rc;
1174
1175                 /* Read block address from indirect block */
1176                 current_block =
1177                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1178
1179                 /* Put back indirect block untouched */
1180                 rc = ext4_block_set(fs->bdev, &block);
1181                 if (rc != EOK)
1182                         return rc;
1183
1184                 /* Check for sparse file */
1185                 if (current_block == 0) {
1186                         *fblock = 0;
1187                         return EOK;
1188                 }
1189
1190                 /* Jump to the next level */
1191                 level--;
1192
1193                 /* Termination condition - we have address of data block loaded
1194                  */
1195                 if (level == 0)
1196                         break;
1197
1198                 /* Visit the next level */
1199                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1200                 offset_in_block = block_offset_in_level /
1201                                   fs->inode_blocks_per_level[level - 1];
1202         }
1203
1204         *fblock = current_block;
1205
1206         return EOK;
1207 }
1208
1209
1210 int ext4_fs_get_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1211                                        uint64_t iblock, ext4_fsblk_t *fblock,
1212                                        bool support_unwritten)
1213 {
1214         return ext4_fs_get_inode_data_block_idx(inode_ref, iblock, fblock,
1215                         false, support_unwritten);
1216 }
1217
1218 int ext4_fs_init_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1219                                        uint64_t iblock, ext4_fsblk_t *fblock)
1220 {
1221         return ext4_fs_get_inode_data_block_idx(inode_ref, iblock, fblock,
1222                         true, true);
1223 }
1224
1225 int ext4_fs_set_inode_data_block_index(struct ext4_inode_ref *inode_ref,
1226                                        uint64_t iblock, ext4_fsblk_t fblock)
1227 {
1228         struct ext4_fs *fs = inode_ref->fs;
1229
1230 #if CONFIG_EXTENT_ENABLE
1231         /* Handle inode using extents */
1232         if ((ext4_sb_has_feature_incompatible(&fs->sb,
1233                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
1234             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1235                 /* Not reachable */
1236                 return ENOTSUP;
1237         }
1238 #endif
1239
1240         /* Handle simple case when we are dealing with direct reference */
1241         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1242                 ext4_inode_set_direct_block(inode_ref->inode, (uint32_t)iblock,
1243                                             (uint32_t)fblock);
1244                 inode_ref->dirty = true;
1245
1246                 return EOK;
1247         }
1248
1249         /* Determine the indirection level needed to get the desired block */
1250         unsigned int level = 0;
1251         unsigned int i;
1252         for (i = 1; i < 4; i++) {
1253                 if (iblock < fs->inode_block_limits[i]) {
1254                         level = i;
1255                         break;
1256                 }
1257         }
1258
1259         if (level == 0)
1260                 return EIO;
1261
1262         uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
1263
1264         /* Compute offsets for the topmost level */
1265         uint64_t block_offset_in_level =
1266             iblock - fs->inode_block_limits[level - 1];
1267         ext4_fsblk_t current_block =
1268             ext4_inode_get_indirect_block(inode_ref->inode, level - 1);
1269         uint32_t offset_in_block =
1270             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1271
1272         ext4_fsblk_t new_block_addr;
1273
1274         struct ext4_block block;
1275         struct ext4_block new_block;
1276
1277         /* Is needed to allocate indirect block on the i-node level */
1278         if (current_block == 0) {
1279                 /* Allocate new indirect block */
1280                 ext4_fsblk_t goal;
1281                 int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
1282                 if (rc != EOK)
1283                         return rc;
1284
1285                 rc = ext4_balloc_alloc_block(inode_ref,
1286                                              goal,
1287                                              &new_block_addr);
1288                 if (rc != EOK)
1289                         return rc;
1290
1291                 /* Update i-node */
1292                 ext4_inode_set_indirect_block(inode_ref->inode, level - 1,
1293                                               (uint32_t)new_block_addr);
1294                 inode_ref->dirty = true;
1295
1296                 /* Load newly allocated block */
1297                 rc = ext4_block_get(fs->bdev, &new_block, new_block_addr);
1298                 if (rc != EOK) {
1299                         ext4_balloc_free_block(inode_ref, new_block_addr);
1300                         return rc;
1301                 }
1302
1303                 /* Initialize new block */
1304                 memset(new_block.data, 0, block_size);
1305                 new_block.dirty = true;
1306
1307                 /* Put back the allocated block */
1308                 rc = ext4_block_set(fs->bdev, &new_block);
1309                 if (rc != EOK)
1310                         return rc;
1311
1312                 current_block = new_block_addr;
1313         }
1314
1315         /*
1316          * Navigate through other levels, until we find the block number
1317          * or find null reference meaning we are dealing with sparse file
1318          */
1319         while (level > 0) {
1320                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1321                 if (rc != EOK)
1322                         return rc;
1323
1324                 current_block =
1325                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1326
1327                 if ((level > 1) && (current_block == 0)) {
1328                         ext4_fsblk_t goal;
1329                         rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
1330                         if (rc != EOK) {
1331                                 ext4_block_set(fs->bdev, &block);
1332                                 return rc;
1333                         }
1334
1335                         /* Allocate new block */
1336                         rc =
1337                             ext4_balloc_alloc_block(inode_ref, goal, &new_block_addr);
1338                         if (rc != EOK) {
1339                                 ext4_block_set(fs->bdev, &block);
1340                                 return rc;
1341                         }
1342
1343                         /* Load newly allocated block */
1344                         rc = ext4_block_get(fs->bdev, &new_block,
1345                                             new_block_addr);
1346
1347                         if (rc != EOK) {
1348                                 ext4_block_set(fs->bdev, &block);
1349                                 return rc;
1350                         }
1351
1352                         /* Initialize allocated block */
1353                         memset(new_block.data, 0, block_size);
1354                         new_block.dirty = true;
1355
1356                         rc = ext4_block_set(fs->bdev, &new_block);
1357                         if (rc != EOK) {
1358                                 ext4_block_set(fs->bdev, &block);
1359                                 return rc;
1360                         }
1361
1362                         /* Write block address to the parent */
1363                         ((uint32_t *)block.data)[offset_in_block] =
1364                             to_le32((uint32_t)new_block_addr);
1365                         block.dirty = true;
1366                         current_block = new_block_addr;
1367                 }
1368
1369                 /* Will be finished, write the fblock address */
1370                 if (level == 1) {
1371                         ((uint32_t *)block.data)[offset_in_block] =
1372                             to_le32((uint32_t)fblock);
1373                         block.dirty = true;
1374                 }
1375
1376                 rc = ext4_block_set(fs->bdev, &block);
1377                 if (rc != EOK)
1378                         return rc;
1379
1380                 level--;
1381
1382                 /*
1383                  * If we are on the last level, break here as
1384                  * there is no next level to visit
1385                  */
1386                 if (level == 0)
1387                         break;
1388
1389                 /* Visit the next level */
1390                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1391                 offset_in_block = block_offset_in_level /
1392                                   fs->inode_blocks_per_level[level - 1];
1393         }
1394
1395         return EOK;
1396 }
1397
1398 int ext4_fs_release_inode_block(struct ext4_inode_ref *inode_ref,
1399                                 uint32_t iblock)
1400 {
1401         ext4_fsblk_t fblock;
1402
1403         struct ext4_fs *fs = inode_ref->fs;
1404
1405         /* Extents are handled otherwise = there is not support in this function
1406          */
1407         ext4_assert(!(
1408             ext4_sb_has_feature_incompatible(&fs->sb,
1409                                              EXT4_FEATURE_INCOMPAT_EXTENTS) &&
1410             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))));
1411
1412         struct ext4_inode *inode = inode_ref->inode;
1413
1414         /* Handle simple case when we are dealing with direct reference */
1415         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
1416                 fblock = ext4_inode_get_direct_block(inode, iblock);
1417
1418                 /* Sparse file */
1419                 if (fblock == 0)
1420                         return EOK;
1421
1422                 ext4_inode_set_direct_block(inode, iblock, 0);
1423                 return ext4_balloc_free_block(inode_ref, fblock);
1424         }
1425
1426         /* Determine the indirection level needed to get the desired block */
1427         unsigned int level = 0;
1428         unsigned int i;
1429         for (i = 1; i < 4; i++) {
1430                 if (iblock < fs->inode_block_limits[i]) {
1431                         level = i;
1432                         break;
1433                 }
1434         }
1435
1436         if (level == 0)
1437                 return EIO;
1438
1439         /* Compute offsets for the topmost level */
1440         uint64_t block_offset_in_level =
1441             iblock - fs->inode_block_limits[level - 1];
1442         ext4_fsblk_t current_block =
1443             ext4_inode_get_indirect_block(inode, level - 1);
1444         uint32_t offset_in_block =
1445             block_offset_in_level / fs->inode_blocks_per_level[level - 1];
1446
1447         /*
1448          * Navigate through other levels, until we find the block number
1449          * or find null reference meaning we are dealing with sparse file
1450          */
1451         struct ext4_block block;
1452
1453         while (level > 0) {
1454
1455                 /* Sparse check */
1456                 if (current_block == 0)
1457                         return EOK;
1458
1459                 int rc = ext4_block_get(fs->bdev, &block, current_block);
1460                 if (rc != EOK)
1461                         return rc;
1462
1463                 current_block =
1464                     to_le32(((uint32_t *)block.data)[offset_in_block]);
1465
1466                 /* Set zero if physical data block address found */
1467                 if (level == 1) {
1468                         ((uint32_t *)block.data)[offset_in_block] = to_le32(0);
1469                         block.dirty = true;
1470                 }
1471
1472                 rc = ext4_block_set(fs->bdev, &block);
1473                 if (rc != EOK)
1474                         return rc;
1475
1476                 level--;
1477
1478                 /*
1479                  * If we are on the last level, break here as
1480                  * there is no next level to visit
1481                  */
1482                 if (level == 0)
1483                         break;
1484
1485                 /* Visit the next level */
1486                 block_offset_in_level %= fs->inode_blocks_per_level[level];
1487                 offset_in_block = block_offset_in_level /
1488                                   fs->inode_blocks_per_level[level - 1];
1489         }
1490
1491         fblock = current_block;
1492         if (fblock == 0)
1493                 return EOK;
1494
1495         /* Physical block is not referenced, it can be released */
1496         return ext4_balloc_free_block(inode_ref, fblock);
1497 }
1498
1499 int ext4_fs_append_inode_block(struct ext4_inode_ref *inode_ref,
1500                                ext4_fsblk_t *fblock, uint32_t *iblock)
1501 {
1502 #if CONFIG_EXTENT_ENABLE
1503         /* Handle extents separately */
1504         if ((ext4_sb_has_feature_incompatible(&inode_ref->fs->sb,
1505                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
1506             (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
1507                 int rc;
1508                 ext4_fsblk_t current_fsblk;
1509                 struct ext4_sblock *sb = &inode_ref->fs->sb;
1510                 uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
1511                 uint32_t block_size = ext4_sb_get_block_size(sb);
1512                 *iblock = (inode_size + block_size - 1) /
1513                                     block_size;
1514
1515                 rc = ext4_extent_get_blocks(inode_ref, *iblock, 1,
1516                                 &current_fsblk, true, NULL);
1517
1518
1519                 *fblock = current_fsblk;
1520                 ext4_assert(*fblock);
1521
1522                 ext4_inode_set_size(inode_ref->inode,
1523                                     inode_size + block_size);
1524                 inode_ref->dirty = true;
1525
1526
1527                 return rc;
1528         }
1529 #endif
1530         struct ext4_sblock *sb = &inode_ref->fs->sb;
1531
1532         /* Compute next block index and allocate data block */
1533         uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
1534         uint32_t block_size = ext4_sb_get_block_size(sb);
1535
1536         /* Align size i-node size */
1537         if ((inode_size % block_size) != 0)
1538                 inode_size += block_size - (inode_size % block_size);
1539
1540         /* Logical blocks are numbered from 0 */
1541         uint32_t new_block_idx = inode_size / block_size;
1542
1543         /* Allocate new physical block */
1544         ext4_fsblk_t goal, phys_block;
1545         int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
1546         if (rc != EOK)
1547                 return rc;
1548
1549         rc = ext4_balloc_alloc_block(inode_ref, goal, &phys_block);
1550         if (rc != EOK)
1551                 return rc;
1552
1553         /* Add physical block address to the i-node */
1554         rc = ext4_fs_set_inode_data_block_index(inode_ref, new_block_idx,
1555                                                 phys_block);
1556         if (rc != EOK) {
1557                 ext4_balloc_free_block(inode_ref, phys_block);
1558                 return rc;
1559         }
1560
1561         /* Update i-node */
1562         ext4_inode_set_size(inode_ref->inode, inode_size + block_size);
1563         inode_ref->dirty = true;
1564
1565         *fblock = phys_block;
1566         *iblock = new_block_idx;
1567
1568         return EOK;
1569 }
1570
1571 void ext4_fs_inode_links_count_inc(struct ext4_inode_ref *inode_ref)
1572 {
1573         uint16_t link;
1574
1575         link = ext4_inode_get_links_count(inode_ref->inode);
1576         link++;
1577         ext4_inode_set_links_count(inode_ref->inode, link);
1578
1579         bool is_dx =
1580             ext4_sb_has_feature_compatible(&inode_ref->fs->sb,
1581                                            EXT4_FEATURE_COMPAT_DIR_INDEX) &&
1582             ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_INDEX);
1583
1584         if (is_dx && link > 1) {
1585                 if (link >= EXT4_LINK_MAX || link == 2) {
1586                         ext4_inode_set_links_count(inode_ref->inode, 1);
1587
1588                         uint32_t v =
1589                             ext4_get32(&inode_ref->fs->sb, features_read_only);
1590                         v |= EXT4_FEATURE_RO_COMPAT_DIR_NLINK;
1591                         ext4_set32(&inode_ref->fs->sb, features_read_only, v);
1592                 }
1593         }
1594 }
1595
1596 void ext4_fs_inode_links_count_dec(struct ext4_inode_ref *inode_ref)
1597 {
1598         uint16_t links = ext4_inode_get_links_count(inode_ref->inode);
1599         if (!ext4_inode_is_type(&inode_ref->fs->sb, inode_ref->inode,
1600                                 EXT4_INODE_MODE_DIRECTORY)) {
1601                 if (links > 0)
1602                         ext4_inode_set_links_count(inode_ref->inode, links - 1);
1603                 return;
1604         }
1605
1606         if (links > 2)
1607                 ext4_inode_set_links_count(inode_ref->inode, links - 1);
1608 }
1609
1610 /**
1611  * @}
1612  */