lwext4/ext4_dir_idx.c

   1 /*
   2  * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup lwext4
  30  * @{
  31  */
  32 /**
  33  * @file  ext4_dir_idx.c
  34  * @brief Directory indexing procedures.
  35  */
  36
  37 #include "ext4_config.h"
  38 #include "ext4_dir_idx.h"
  39 #include "ext4_dir.h"
  40 #include "ext4_blockdev.h"
  41 #include "ext4_fs.h"
  42 #include "ext4_super.h"
  43 #include "ext4_inode.h"
  44 #include "ext4_crc32c.h"
  45 #include "ext4_hash.h"
  46
  47 #include <string.h>
  48 #include <stdlib.h>
  49
  50 /**@brief Get hash version used in directory index.
  51  * @param root_info Pointer to root info structure of index
  52  * @return Hash algorithm version
  53  */
  54 static inline uint8_t ext4_dir_dx_root_info_get_hash_version(
  55     struct ext4_dir_idx_root_info *root_info)
  56 {
  57         return root_info->hash_version;
  58 }
  59
  60 /**@brief Set hash version, that will be used in directory index.
  61  * @param root_info Pointer to root info structure of index
  62  * @param v Hash algorithm version
  63  */
  64 static inline void ext4_dir_dx_root_info_set_hash_version(
  65     struct ext4_dir_idx_root_info *root_info, uint8_t v)
  66 {
  67         root_info->hash_version = v;
  68 }
  69
  70 /**@brief Get length of root_info structure in bytes.
  71  * @param root_info Pointer to root info structure of index
  72  * @return Length of the structure
  73  */
  74 static inline uint8_t ext4_dir_dx_root_info_get_info_length(
  75     struct ext4_dir_idx_root_info *root_info)
  76 {
  77         return root_info->info_length;
  78 }
  79
  80 /**@brief Set length of root_info structure in bytes.
  81  * @param root_info   Pointer to root info structure of index
  82  * @param info_length Length of the structure
  83  */
  84 static inline void ext4_dir_dx_root_info_set_info_length(
  85     struct ext4_dir_idx_root_info *root_info, uint8_t len)
  86 {
  87         root_info->info_length = len;
  88 }
  89
  90 /**@brief Get number of indirect levels of HTree.
  91  * @param root_info Pointer to root info structure of index
  92  * @return Height of HTree (actually only 0 or 1)
  93  */
  94 static inline uint8_t ext4_dir_dx_root_info_get_indirect_levels(
  95     struct ext4_dir_idx_root_info *root_info)
  96 {
  97         return root_info->indirect_levels;
  98 }
  99
 100 /**@brief Set number of indirect levels of HTree.
 101  * @param root_info Pointer to root info structure of index
 102  * @param lvl Height of HTree (actually only 0 or 1)
 103  */
 104 static inline void ext4_dir_dx_root_info_set_indirect_levels(
 105     struct ext4_dir_idx_root_info *root_info, uint8_t lvl)
 106 {
 107         root_info->indirect_levels = lvl;
 108 }
 109
 110 /**@brief Get maximum number of index node entries.
 111  * @param climit Pointer to counlimit structure
 112  * @return Maximum of entries in node
 113  */
 114 static inline uint16_t
 115 ext4_dir_dx_countlimit_get_limit(struct ext4_dir_idx_countlimit *climit)
 116 {
 117         return to_le16(climit->limit);
 118 }
 119
 120 /**@brief Set maximum number of index node entries.
 121  * @param climit Pointer to counlimit structure
 122  * @param limit Maximum of entries in node
 123  */
 124 static inline void
 125 ext4_dir_dx_countlimit_set_limit(struct ext4_dir_idx_countlimit *climit,
 126                                  uint16_t limit)
 127 {
 128         climit->limit = to_le16(limit);
 129 }
 130
 131 /**@brief Get current number of index node entries.
 132  * @param climit Pointer to counlimit structure
 133  * @return Number of entries in node
 134  */
 135 static inline uint16_t
 136 ext4_dir_dx_countlimit_get_count(struct ext4_dir_idx_countlimit *climit)
 137 {
 138         return to_le16(climit->count);
 139 }
 140
 141 /**@brief Set current number of index node entries.
 142  * @param climit Pointer to counlimit structure
 143  * @param count Number of entries in node
 144  */
 145 static inline void
 146 ext4_dir_dx_countlimit_set_count(struct ext4_dir_idx_countlimit *climit,
 147                                  uint16_t count)
 148 {
 149         climit->count = to_le16(count);
 150 }
 151
 152 /**@brief Get hash value of index entry.
 153  * @param entry Pointer to index entry
 154  * @return Hash value
 155  */
 156 static inline uint32_t
 157 ext4_dir_dx_entry_get_hash(struct ext4_dir_idx_entry *entry)
 158 {
 159         return to_le32(entry->hash);
 160 }
 161
 162 /**@brief Set hash value of index entry.
 163  * @param entry Pointer to index entry
 164  * @param hash  Hash value
 165  */
 166 static inline void
 167 ext4_dir_dx_entry_set_hash(struct ext4_dir_idx_entry *entry, uint32_t hash)
 168 {
 169         entry->hash = to_le32(hash);
 170 }
 171
 172 /**@brief Get block address where child node is located.
 173  * @param entry Pointer to index entry
 174  * @return Block address of child node
 175  */
 176 static inline uint32_t
 177 ext4_dir_dx_entry_get_block(struct ext4_dir_idx_entry *entry)
 178 {
 179         return to_le32(entry->block);
 180 }
 181
 182 /**@brief Set block address where child node is located.
 183  * @param entry Pointer to index entry
 184  * @param block Block address of child node
 185  */
 186 static inline void
 187 ext4_dir_dx_entry_set_block(struct ext4_dir_idx_entry *entry,
 188                             uint32_t block)
 189 {
 190         entry->block = to_le32(block);
 191 }
 192
 193 /**@brief Sort entry item.*/
 194 struct ext4_dx_sort_entry {
 195         uint32_t hash;
 196         uint32_t rec_len;
 197         void *dentry;
 198 };
 199
 200 static int ext4_dir_dx_hash_string(struct ext4_hash_info *hinfo, int len,
 201                                    const char *name)
 202 {
 203         return ext2_htree_hash(name, len, hinfo->seed, hinfo->hash_version,
 204                                &hinfo->hash, &hinfo->minor_hash);
 205 }
 206
 207 #if CONFIG_META_CSUM_ENABLE
 208 static uint32_t
 209 ext4_dir_dx_checksum(struct ext4_inode_ref *inode_ref,
 210                  void *dirent,
 211                  int count_offset, int count, struct ext4_dir_idx_tail *t)
 212 {
 213         uint32_t orig_checksum, checksum = 0;
 214         struct ext4_sblock *sb = &inode_ref->fs->sb;
 215         int size;
 216
 217         /* Compute the checksum only if the filesystem supports it */
 218         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
 219                 uint32_t ino_index = to_le32(inode_ref->index);
 220                 uint32_t ino_gen =
 221                         to_le32(ext4_inode_get_generation(inode_ref->inode));
 222
 223                 size = count_offset +
 224                         (count * sizeof(struct ext4_dir_idx_tail));
 225                 orig_checksum = t->checksum;
 226                 t->checksum = 0;
 227                 /* First calculate crc32 checksum against fs uuid */
 228                 checksum = ext4_crc32c(EXT4_CRC32_INIT, sb->uuid,
 229                                 sizeof(sb->uuid));
 230                 /* Then calculate crc32 checksum against inode number
 231                  * and inode generation */
 232                 checksum = ext4_crc32c(checksum, &ino_index,
 233                                      sizeof(ino_index));
 234                 checksum = ext4_crc32c(checksum, &ino_gen,
 235                                      sizeof(ino_gen));
 236                 /* After that calculate crc32 checksum against all the dx_entry */
 237                 checksum = ext4_crc32c(checksum, dirent, size);
 238                 /* Finally calculate crc32 checksum for dx_tail */
 239                 checksum = ext4_crc32c(checksum, t,
 240                                 sizeof(struct ext4_dir_idx_tail));
 241                 t->checksum = orig_checksum;
 242         }
 243         return checksum;
 244 }
 245
 246 static struct ext4_dir_idx_countlimit *
 247 ext4_dir_dx_get_countlimit(struct ext4_inode_ref *inode_ref,
 248                         struct ext4_dir_entry_ll *dirent,
 249                         int *offset)
 250 {
 251         struct ext4_dir_entry_ll *dp;
 252         struct ext4_dir_idx_root *root;
 253         struct ext4_sblock *sb = &inode_ref->fs->sb;
 254         int count_offset;
 255
 256         if (ext4_dir_entry_ll_get_entry_length(dirent) ==
 257                         ext4_sb_get_block_size(sb))
 258                 count_offset = 8;
 259         else if (ext4_dir_entry_ll_get_entry_length(dirent) == 12) {
 260                 root = (struct ext4_dir_idx_root *)dirent;
 261                 dp = (struct ext4_dir_entry_ll *)&root->dots[1];
 262                 if (ext4_dir_entry_ll_get_entry_length(dp) !=
 263                     ext4_sb_get_block_size(sb) - 12)
 264                         return NULL;
 265                 if (root->info.reserved_zero ||
 266                     root->info.info_length != sizeof(struct ext4_dir_idx_root_info))
 267                         return NULL;
 268                 count_offset = 32;
 269         } else
 270                 return NULL;
 271
 272         if (offset)
 273                 *offset = count_offset;
 274         return (struct ext4_dir_idx_countlimit *)(((char *)dirent) + count_offset);
 275 }
 276
 277 /*
 278  * BIG FAT NOTES:
 279  *       Currently we do not verify the checksum of HTree node.
 280  */
 281 static bool
 282 ext4_dir_dx_checksum_verify(struct ext4_inode_ref *inode_ref,
 283                                 struct ext4_dir_entry_ll *dirent)
 284 {
 285         struct ext4_sblock *sb = &inode_ref->fs->sb;
 286         int count_offset, limit, count;
 287
 288         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
 289                 struct ext4_dir_idx_countlimit *countlimit =
 290                         ext4_dir_dx_get_countlimit(inode_ref, dirent, &count_offset);
 291                 if (!countlimit) {
 292                         /* Directory seems corrupted. */
 293                         return true;
 294                 }
 295                 struct ext4_dir_idx_tail *t;
 296                 limit = ext4_dir_dx_countlimit_get_limit(countlimit);
 297                 count = ext4_dir_dx_countlimit_get_count(countlimit);
 298                 if (count_offset + (limit * sizeof(struct ext4_dir_idx_entry)) >
 299                                 ext4_sb_get_block_size(sb) -
 300                                 sizeof(struct ext4_dir_idx_tail)) {
 301                         /* There is no space to hold the checksum */
 302                         return true;
 303                 }
 304                 t = (void *)(((struct ext4_dir_idx_entry *)countlimit) + limit);
 305
 306                 if (t->checksum != to_le32(ext4_dir_dx_checksum(inode_ref,
 307                                                                 dirent,
 308                                                                 count_offset,
 309                                                                 count, t)))
 310                         return false;
 311         }
 312         return true;
 313 }
 314
 315
 316 static void
 317 ext4_dir_set_dx_checksum(struct ext4_inode_ref *inode_ref,
 318                         struct ext4_dir_entry_ll *dirent)
 319 {
 320         int count_offset, limit, count;
 321         struct ext4_sblock *sb = &inode_ref->fs->sb;
 322
 323         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
 324                 struct ext4_dir_idx_countlimit *countlimit =
 325                         ext4_dir_dx_get_countlimit(inode_ref, dirent, &count_offset);
 326                 if (!countlimit) {
 327                         /* Directory seems corrupted. */
 328                         return;
 329                 }
 330                 struct ext4_dir_idx_tail *t;
 331                 limit = ext4_dir_dx_countlimit_get_limit(countlimit);
 332                 count = ext4_dir_dx_countlimit_get_count(countlimit);
 333                 if (count_offset + (limit * sizeof(struct ext4_dir_idx_entry)) >
 334                                 ext4_sb_get_block_size(sb) -
 335                                 sizeof(struct ext4_dir_idx_tail)) {
 336                         /* There is no space to hold the checksum */
 337                         return;
 338                 }
 339                 t = (struct ext4_dir_idx_tail *)
 340                         (((struct ext4_dir_idx_entry *)countlimit) + limit);
 341
 342                 t->checksum = to_le32(ext4_dir_dx_checksum(inode_ref, dirent,
 343                                         count_offset, count, t));
 344         }
 345 }
 346 #else
 347 #define ext4_dir_dx_checksum_verify(...) true
 348 #define ext4_dir_set_dx_checksum(...)
 349 #endif
 350
 351 /****************************************************************************/
 352
 353 int ext4_dir_dx_init(struct ext4_inode_ref *dir, struct ext4_inode_ref *parent)
 354 {
 355         /* Load block 0, where will be index root located */
 356         ext4_fsblk_t fblock;
 357         uint32_t iblock;
 358         struct ext4_sblock *sb = &dir->fs->sb;
 359         int rc = ext4_fs_append_inode_block(dir, &fblock, &iblock);
 360         if (rc != EOK)
 361                 return rc;
 362
 363         struct ext4_block block;
 364         rc = ext4_block_get(dir->fs->bdev, &block, fblock);
 365         if (rc != EOK)
 366                 return rc;
 367
 368         /* Initialize pointers to data structures */
 369         struct ext4_dir_idx_root *root = (void *)block.data;
 370         struct ext4_dir_idx_root_info *info = &(root->info);
 371
 372         /* Initialize dot entries */
 373         ext4_dir_write_entry(&dir->fs->sb,
 374                         (struct ext4_dir_entry_ll *)root->dots,
 375                         12,
 376                         dir,
 377                         ".",
 378                         strlen("."));
 379
 380         ext4_dir_write_entry(&dir->fs->sb,
 381                         (struct ext4_dir_entry_ll *)(root->dots + 1),
 382                         ext4_sb_get_block_size(sb) - 12,
 383                         parent,
 384                         "..",
 385                         strlen(".."));
 386
 387         /* Initialize root info structure */
 388         uint8_t hash_version = ext4_get8(&dir->fs->sb, default_hash_version);
 389
 390         ext4_dir_dx_root_info_set_hash_version(info, hash_version);
 391         ext4_dir_dx_root_info_set_indirect_levels(info, 0);
 392         ext4_dir_dx_root_info_set_info_length(info, 8);
 393
 394         /* Set limit and current number of entries */
 395         struct ext4_dir_idx_countlimit *countlimit =
 396             (struct ext4_dir_idx_countlimit *)&root->entries;
 397
 398         ext4_dir_dx_countlimit_set_count(countlimit, 1);
 399
 400         uint32_t block_size = ext4_sb_get_block_size(&dir->fs->sb);
 401         uint32_t entry_space = block_size -
 402                                2 * sizeof(struct ext4_dir_idx_dot_entry) -
 403                                sizeof(struct ext4_dir_idx_root_info);
 404         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 405                 entry_space -= sizeof(struct ext4_dir_idx_tail);
 406
 407         uint16_t root_limit =
 408             entry_space / sizeof(struct ext4_dir_idx_entry);
 409
 410         ext4_dir_dx_countlimit_set_limit(countlimit, root_limit);
 411
 412         /* Append new block, where will be new entries inserted in the future */
 413         rc = ext4_fs_append_inode_block(dir, &fblock, &iblock);
 414         if (rc != EOK) {
 415                 ext4_block_set(dir->fs->bdev, &block);
 416                 return rc;
 417         }
 418
 419         struct ext4_block new_block;
 420
 421         rc = ext4_block_get(dir->fs->bdev, &new_block, fblock);
 422         if (rc != EOK) {
 423                 ext4_block_set(dir->fs->bdev, &block);
 424                 return rc;
 425         }
 426
 427         /* Fill the whole block with empty entry */
 428         struct ext4_dir_entry_ll *block_entry = (void *)new_block.data;
 429
 430         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
 431                 ext4_dir_entry_ll_set_entry_length(block_entry,
 432                                 block_size -
 433                                 sizeof(struct ext4_dir_entry_tail));
 434                 ext4_dir_entry_ll_set_name_length(sb,
 435                                                   block_entry,
 436                                                   0);
 437                 ext4_dir_entry_ll_set_inode_type(sb,
 438                                                  block_entry,
 439                                                  EXT4_DIRENTRY_UNKNOWN);
 440
 441                 initialize_dir_tail(EXT4_DIRENT_TAIL(block_entry,
 442                                         ext4_sb_get_block_size(sb)));
 443                 ext4_dir_set_checksum(dir,
 444                                 (struct ext4_dir_entry_ll *)new_block.data);
 445         } else {
 446                 ext4_dir_entry_ll_set_entry_length(block_entry, block_size);
 447         }
 448
 449         ext4_dir_entry_ll_set_inode(block_entry, 0);
 450
 451         new_block.dirty = true;
 452         rc = ext4_block_set(dir->fs->bdev, &new_block);
 453         if (rc != EOK) {
 454                 ext4_block_set(dir->fs->bdev, &block);
 455                 return rc;
 456         }
 457
 458         /* Connect new block to the only entry in index */
 459         struct ext4_dir_idx_entry *entry = root->entries;
 460         ext4_dir_dx_entry_set_block(entry, iblock);
 461
 462         ext4_dir_set_dx_checksum(dir,
 463                         (struct ext4_dir_entry_ll *)block.data);
 464         block.dirty = true;
 465
 466         return ext4_block_set(dir->fs->bdev, &block);
 467 }
 468
 469 /**@brief Initialize hash info structure necessary for index operations.
 470  * @param hinfo      Pointer to hinfo to be initialized
 471  * @param root_block Root block (number 0) of index
 472  * @param sb         Pointer to superblock
 473  * @param name_len   Length of name to be computed hash value from
 474  * @param name       Name to be computed hash value from
 475  * @return Standard error code
 476  */
 477 static int ext4_dir_hinfo_init(struct ext4_hash_info *hinfo,
 478                                struct ext4_block *root_block,
 479                                struct ext4_sblock *sb, size_t name_len,
 480                                const char *name)
 481 {
 482         struct ext4_dir_idx_root *root =
 483             (struct ext4_dir_idx_root *)root_block->data;
 484
 485         if ((root->info.hash_version != EXT2_HTREE_LEGACY) &&
 486             (root->info.hash_version != EXT2_HTREE_HALF_MD4) &&
 487             (root->info.hash_version != EXT2_HTREE_TEA))
 488                 return EXT4_ERR_BAD_DX_DIR;
 489
 490         /* Check unused flags */
 491         if (root->info.unused_flags != 0)
 492                 return EXT4_ERR_BAD_DX_DIR;
 493
 494         /* Check indirect levels */
 495         if (root->info.indirect_levels > 1)
 496                 return EXT4_ERR_BAD_DX_DIR;
 497
 498         /* Check if node limit is correct */
 499         uint32_t block_size = ext4_sb_get_block_size(sb);
 500         uint32_t entry_space = block_size;
 501         entry_space -= 2 * sizeof(struct ext4_dir_idx_dot_entry);
 502         entry_space -= sizeof(struct ext4_dir_idx_root_info);
 503         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 504                 entry_space -= sizeof(struct ext4_dir_idx_tail);
 505         entry_space = entry_space / sizeof(struct ext4_dir_idx_entry);
 506
 507         uint16_t limit = ext4_dir_dx_countlimit_get_limit(
 508             (struct ext4_dir_idx_countlimit *)&root->entries);
 509         if (limit != entry_space)
 510                 return EXT4_ERR_BAD_DX_DIR;
 511
 512         /* Check hash version and modify if necessary */
 513         hinfo->hash_version =
 514             ext4_dir_dx_root_info_get_hash_version(&root->info);
 515         if ((hinfo->hash_version <= EXT2_HTREE_TEA) &&
 516             (ext4_sb_check_flag(sb, EXT4_SUPERBLOCK_FLAGS_UNSIGNED_HASH))) {
 517                 /* Use unsigned hash */
 518                 hinfo->hash_version += 3;
 519         }
 520
 521         /* Load hash seed from superblock */
 522
 523         hinfo->seed = ext4_get8(sb, hash_seed);
 524
 525         /* Compute hash value of name */
 526         if (name)
 527                 return ext4_dir_dx_hash_string(hinfo, name_len, name);
 528
 529         return EOK;
 530 }
 531
 532 /**@brief Walk through index tree and load leaf with corresponding hash value.
 533  * @param hinfo      Initialized hash info structure
 534  * @param inode_ref  Current i-node
 535  * @param root_block Root block (iblock 0), where is root node located
 536  * @param dx_block   Pointer to leaf node in dx_blocks array
 537  * @param dx_blocks  Array with the whole path from root to leaf
 538  * @return Standard error code
 539  */
 540 static int ext4_dir_dx_get_leaf(struct ext4_hash_info *hinfo,
 541                                 struct ext4_inode_ref *inode_ref,
 542                                 struct ext4_block *root_block,
 543                                 struct ext4_dir_idx_block **dx_block,
 544                                 struct ext4_dir_idx_block *dx_blocks)
 545 {
 546         struct ext4_dir_idx_block *tmp_dx_block = dx_blocks;
 547         struct ext4_dir_idx_root *root =
 548             (struct ext4_dir_idx_root *)root_block->data;
 549         struct ext4_dir_idx_entry *entries =
 550             (struct ext4_dir_idx_entry *)&root->entries;
 551
 552         uint16_t limit = ext4_dir_dx_countlimit_get_limit(
 553             (struct ext4_dir_idx_countlimit *)entries);
 554         uint8_t indirect_level =
 555             ext4_dir_dx_root_info_get_indirect_levels(&root->info);
 556
 557         struct ext4_block *tmp_block = root_block;
 558         struct ext4_dir_idx_entry *p;
 559         struct ext4_dir_idx_entry *q;
 560         struct ext4_dir_idx_entry *m;
 561         struct ext4_dir_idx_entry *at;
 562
 563         /* Walk through the index tree */
 564         while (true) {
 565                 uint16_t count = ext4_dir_dx_countlimit_get_count(
 566                     (struct ext4_dir_idx_countlimit *)entries);
 567                 if ((count == 0) || (count > limit))
 568                         return EXT4_ERR_BAD_DX_DIR;
 569
 570                 /* Do binary search in every node */
 571                 p = entries + 1;
 572                 q = entries + count - 1;
 573
 574                 while (p <= q) {
 575                         m = p + (q - p) / 2;
 576                         if (ext4_dir_dx_entry_get_hash(m) > hinfo->hash)
 577                                 q = m - 1;
 578                         else
 579                                 p = m + 1;
 580                 }
 581
 582                 at = p - 1;
 583
 584                 /* Write results */
 585
 586                 memcpy(&tmp_dx_block->block, tmp_block,
 587                        sizeof(struct ext4_block));
 588                 tmp_dx_block->entries = entries;
 589                 tmp_dx_block->position = at;
 590
 591                 /* Is algorithm in the leaf? */
 592                 if (indirect_level == 0) {
 593                         *dx_block = tmp_dx_block;
 594                         return EOK;
 595                 }
 596
 597                 /* Goto child node */
 598                 uint32_t next_block = ext4_dir_dx_entry_get_block(at);
 599
 600                 indirect_level--;
 601
 602                 ext4_fsblk_t fblock;
 603                 int rc = ext4_fs_get_inode_data_block_index(
 604                     inode_ref, next_block, &fblock, false);
 605                 if (rc != EOK)
 606                         return rc;
 607
 608                 rc = ext4_block_get(inode_ref->fs->bdev, tmp_block, fblock);
 609                 if (rc != EOK)
 610                         return rc;
 611
 612                 entries =
 613                     ((struct ext4_dir_idx_node *)tmp_block->data)->entries;
 614                 limit = ext4_dir_dx_countlimit_get_limit(
 615                     (struct ext4_dir_idx_countlimit *)entries);
 616
 617                 struct ext4_sblock *sb = &inode_ref->fs->sb;
 618                 uint16_t entry_space = ext4_sb_get_block_size(sb) -
 619                                 sizeof(struct ext4_fake_dir_entry);
 620
 621                 if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 622                         entry_space -= sizeof(struct ext4_dir_idx_tail);
 623
 624                 entry_space = entry_space / sizeof(struct ext4_dir_idx_entry);
 625
 626                 if (limit != entry_space) {
 627                         ext4_block_set(inode_ref->fs->bdev, tmp_block);
 628                         return EXT4_ERR_BAD_DX_DIR;
 629                 }
 630
 631                 if (!ext4_dir_dx_checksum_verify(inode_ref,
 632                                 (struct ext4_dir_entry_ll *)tmp_block->data)) {
 633                         ext4_dbg(DEBUG_DIR_IDX,
 634                                         DBG_WARN "HTree checksum failed."
 635                                         "Inode: %" PRIu32", "
 636                                         "Block: %" PRIu32"\n",
 637                                         inode_ref->index,
 638                                         next_block);
 639                 }
 640
 641                 ++tmp_dx_block;
 642         }
 643
 644         /* Unreachable */
 645         return EOK;
 646 }
 647
 648 /**@brief Check if the the next block would be checked during entry search.
 649  * @param inode_ref Directory i-node
 650  * @param hash      Hash value to check
 651  * @param dx_block  Current block
 652  * @param dx_blocks Array with path from root to leaf node
 653  * @return Standard Error code
 654  */
 655 static int ext4_dir_dx_next_block(struct ext4_inode_ref *inode_ref,
 656                                   uint32_t hash,
 657                                   struct ext4_dir_idx_block *dx_block,
 658                                   struct ext4_dir_idx_block *dx_blocks)
 659 {
 660         uint32_t num_handles = 0;
 661         struct ext4_dir_idx_block *p = dx_block;
 662
 663         /* Try to find data block with next bunch of entries */
 664         while (true) {
 665                 p->position++;
 666                 uint16_t count = ext4_dir_dx_countlimit_get_count(
 667                     (struct ext4_dir_idx_countlimit *)p->entries);
 668
 669                 if (p->position < p->entries + count)
 670                         break;
 671
 672                 if (p == dx_blocks)
 673                         return EOK;
 674
 675                 num_handles++;
 676                 p--;
 677         }
 678
 679         /* Check hash collision (if not occurred - no next block cannot be
 680          * used)*/
 681         uint32_t current_hash = ext4_dir_dx_entry_get_hash(p->position);
 682         if ((hash & 1) == 0) {
 683                 if ((current_hash & ~1) != hash)
 684                         return 0;
 685         }
 686
 687         /* Fill new path */
 688         while (num_handles--) {
 689                 uint32_t block_idx = ext4_dir_dx_entry_get_block(p->position);
 690                 ext4_fsblk_t block_addr;
 691
 692                 int rc = ext4_fs_get_inode_data_block_index(
 693                     inode_ref, block_idx, &block_addr, false);
 694                 if (rc != EOK)
 695                         return rc;
 696
 697                 struct ext4_block block;
 698                 rc = ext4_block_get(inode_ref->fs->bdev, &block, block_addr);
 699                 if (rc != EOK)
 700                         return rc;
 701
 702                 if (!ext4_dir_dx_checksum_verify(inode_ref,
 703                                 (struct ext4_dir_entry_ll *)block.data)) {
 704                         ext4_dbg(DEBUG_DIR_IDX,
 705                                         DBG_WARN "HTree checksum failed."
 706                                         "Inode: %" PRIu32", "
 707                                         "Block: %" PRIu32"\n",
 708                                         inode_ref->index,
 709                                         block_idx);
 710                 }
 711
 712                 p++;
 713
 714                 /* Don't forget to put old block (prevent memory leak) */
 715                 rc = ext4_block_set(inode_ref->fs->bdev, &p->block);
 716                 if (rc != EOK)
 717                         return rc;
 718
 719                 memcpy(&p->block, &block, sizeof(block));
 720                 p->entries =
 721                     ((struct ext4_dir_idx_node *)block.data)->entries;
 722                 p->position = p->entries;
 723         }
 724
 725         return ENOENT;
 726 }
 727
 728 int ext4_dir_dx_find_entry(struct ext4_dir_search_result *result,
 729                            struct ext4_inode_ref *inode_ref, size_t name_len,
 730                            const char *name)
 731 {
 732         /* Load direct block 0 (index root) */
 733         ext4_fsblk_t root_block_addr;
 734         int rc2;
 735         int rc =
 736             ext4_fs_get_inode_data_block_index(inode_ref,
 737                             0, &root_block_addr, false);
 738         if (rc != EOK)
 739                 return rc;
 740
 741         struct ext4_fs *fs = inode_ref->fs;
 742
 743         struct ext4_block root_block;
 744         rc = ext4_block_get(fs->bdev, &root_block, root_block_addr);
 745         if (rc != EOK)
 746                 return rc;
 747
 748         if (!ext4_dir_dx_checksum_verify(inode_ref,
 749                                 (struct ext4_dir_entry_ll *)root_block.data)) {
 750                 ext4_dbg(DEBUG_DIR_IDX,
 751                          DBG_WARN "HTree root checksum failed."
 752                          "Inode: %" PRIu32", "
 753                          "Block: %" PRIu32"\n",
 754                          inode_ref->index,
 755                          (uint32_t)0);
 756         }
 757
 758         /* Initialize hash info (compute hash value) */
 759         struct ext4_hash_info hinfo;
 760         rc = ext4_dir_hinfo_init(&hinfo, &root_block, &fs->sb, name_len, name);
 761         if (rc != EOK) {
 762                 ext4_block_set(fs->bdev, &root_block);
 763                 return EXT4_ERR_BAD_DX_DIR;
 764         }
 765
 766         /*
 767          * Hardcoded number 2 means maximum height of index tree,
 768          * specified in the Linux driver.
 769          */
 770         struct ext4_dir_idx_block dx_blocks[2];
 771         struct ext4_dir_idx_block *dx_block;
 772         struct ext4_dir_idx_block *tmp;
 773
 774         rc = ext4_dir_dx_get_leaf(&hinfo, inode_ref, &root_block, &dx_block,
 775                                   dx_blocks);
 776         if (rc != EOK) {
 777                 ext4_block_set(fs->bdev, &root_block);
 778                 return EXT4_ERR_BAD_DX_DIR;
 779         }
 780
 781         do {
 782                 /* Load leaf block */
 783                 uint32_t leaf_block_idx =
 784                     ext4_dir_dx_entry_get_block(dx_block->position);
 785                 ext4_fsblk_t leaf_block_addr;
 786
 787                 rc = ext4_fs_get_inode_data_block_index(
 788                     inode_ref, leaf_block_idx, &leaf_block_addr,
 789                     false);
 790                 if (rc != EOK)
 791                         goto cleanup;
 792
 793                 struct ext4_block leaf_block;
 794                 rc = ext4_block_get(fs->bdev, &leaf_block, leaf_block_addr);
 795                 if (rc != EOK)
 796                         goto cleanup;
 797
 798                 if (!ext4_dir_checksum_verify(inode_ref,
 799                                 (struct ext4_dir_entry_ll *)leaf_block.data)) {
 800                         ext4_dbg(DEBUG_DIR_IDX,
 801                                  DBG_WARN "HTree leaf block checksum failed."
 802                                  "Inode: %" PRIu32", "
 803                                  "Block: %" PRIu32"\n",
 804                                  inode_ref->index,
 805                                  leaf_block_idx);
 806                 }
 807
 808                 /* Linear search inside block */
 809                 struct ext4_dir_entry_ll *res_dentry;
 810                 rc = ext4_dir_find_in_block(&leaf_block, &fs->sb, name_len,
 811                                             name, &res_dentry);
 812
 813                 /* Found => return it */
 814                 if (rc == EOK) {
 815                         result->block = leaf_block;
 816                         result->dentry = res_dentry;
 817                         goto cleanup;
 818                 }
 819
 820                 /* Not found, leave untouched */
 821                 rc2 = ext4_block_set(fs->bdev, &leaf_block);
 822                 if (rc2 != EOK)
 823                         goto cleanup;
 824
 825                 if (rc != ENOENT)
 826                         goto cleanup;
 827
 828                 /* check if the next block could be checked */
 829                 rc = ext4_dir_dx_next_block(inode_ref, hinfo.hash, dx_block,
 830                                             &dx_blocks[0]);
 831                 if (rc < 0)
 832                         goto cleanup;
 833         } while (rc == ENOENT);
 834
 835         /* Entry not found */
 836         rc = ENOENT;
 837
 838 cleanup:
 839         /* The whole path must be released (preventing memory leak) */
 840         tmp = dx_blocks;
 841
 842         while (tmp <= dx_block) {
 843                 rc2 = ext4_block_set(fs->bdev, &tmp->block);
 844                 if (rc == EOK && rc2 != EOK)
 845                         rc = rc2;
 846                 ++tmp;
 847         }
 848
 849         return rc;
 850 }
 851
 852 #if CONFIG_DIR_INDEX_COMB_SORT
 853 #define SWAP_ENTRY(se1, se2)                                                   \
 854         do {                                                                   \
 855                 struct ext4_dx_sort_entry tmp = se1;                           \
 856                 se1 = se2;                                                     \
 857                 se2 = tmp;                                                     \
 858         \
 859 } while (0)
 860
 861 static void comb_sort(struct ext4_dx_sort_entry *se, uint32_t count)
 862 {
 863         struct ext4_dx_sort_entry *p, *q, *top = se + count - 1;
 864         bool more;
 865         /* Combsort */
 866         while (count > 2) {
 867                 count = (count * 10) / 13;
 868                 if (count - 9 < 2)
 869                         count = 11;
 870                 for (p = top, q = p - count; q >= se; p--, q--)
 871                         if (p->hash < q->hash)
 872                                 SWAP_ENTRY(*p, *q);
 873         }
 874         /* Bubblesort */
 875         do {
 876                 more = 0;
 877                 q = top;
 878                 while (q-- > se) {
 879                         if (q[1].hash >= q[0].hash)
 880                                 continue;
 881                         SWAP_ENTRY(*(q + 1), *q);
 882                         more = 1;
 883                 }
 884         } while (more);
 885 }
 886 #else
 887
 888 /**@brief  Compare function used to pass in quicksort implementation.
 889  *         It can compare two entries by hash value.
 890  * @param arg1  First entry
 891  * @param arg2  Second entry
 892  * @param dummy Unused parameter, can be NULL
 893  *
 894  * @return Classic compare result
 895  *         (0: equal, -1: arg1 < arg2, 1: arg1 > arg2)
 896  */
 897 static int ext4_dir_dx_entry_comparator(const void *arg1, const void *arg2)
 898 {
 899         struct ext4_dx_sort_entry *entry1 = (void *)arg1;
 900         struct ext4_dx_sort_entry *entry2 = (void *)arg2;
 901
 902         if (entry1->hash == entry2->hash)
 903                 return 0;
 904
 905         if (entry1->hash < entry2->hash)
 906                 return -1;
 907         else
 908                 return 1;
 909 }
 910 #endif
 911
 912 /**@brief  Insert new index entry to block.
 913  *         Note that space for new entry must be checked by caller.
 914  * @param inode_ref   Directory i-node
 915  * @param index_block Block where to insert new entry
 916  * @param hash        Hash value covered by child node
 917  * @param iblock      Logical number of child block
 918  *
 919  */
 920 static void
 921 ext4_dir_dx_insert_entry(struct ext4_inode_ref *inode_ref __unused,
 922                          struct ext4_dir_idx_block *index_block,
 923                          uint32_t hash, uint32_t iblock)
 924 {
 925         struct ext4_dir_idx_entry *old_index_entry = index_block->position;
 926         struct ext4_dir_idx_entry *new_index_entry = old_index_entry + 1;
 927
 928         struct ext4_dir_idx_countlimit *countlimit =
 929             (struct ext4_dir_idx_countlimit *)index_block->entries;
 930         uint32_t count = ext4_dir_dx_countlimit_get_count(countlimit);
 931
 932         struct ext4_dir_idx_entry *start_index = index_block->entries;
 933         size_t bytes =
 934             (uint8_t *)(start_index + count) - (uint8_t *)(new_index_entry);
 935
 936         memmove(new_index_entry + 1, new_index_entry, bytes);
 937
 938         ext4_dir_dx_entry_set_block(new_index_entry, iblock);
 939         ext4_dir_dx_entry_set_hash(new_index_entry, hash);
 940
 941         ext4_dir_dx_countlimit_set_count(countlimit, count + 1);
 942
 943         ext4_dir_set_dx_checksum(inode_ref,
 944                         (struct ext4_dir_entry_ll *)index_block->block.data);
 945         index_block->block.dirty = true;
 946 }
 947
 948 /**@brief Split directory entries to two parts preventing node overflow.
 949  * @param inode_ref      Directory i-node
 950  * @param hinfo          Hash info
 951  * @param old_data_block Block with data to be split
 952  * @param index_block    Block where index entries are located
 953  * @param new_data_block Output value for newly allocated data block
 954  */
 955 static int ext4_dir_dx_split_data(struct ext4_inode_ref *inode_ref,
 956                                   struct ext4_hash_info *hinfo,
 957                                   struct ext4_block *old_data_block,
 958                                   struct ext4_dir_idx_block *index_block,
 959                                   struct ext4_block *new_data_block)
 960 {
 961         int rc = EOK;
 962
 963         /* Allocate buffer for directory entries */
 964         uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
 965
 966         uint8_t *entry_buffer = malloc(block_size);
 967         if (entry_buffer == NULL)
 968                 return ENOMEM;
 969
 970         /* dot entry has the smallest size available */
 971         uint32_t max_entry_count =
 972             block_size / sizeof(struct ext4_dir_idx_dot_entry);
 973
 974         /* Allocate sort entry */
 975         struct ext4_dx_sort_entry *sort_array =
 976             malloc(max_entry_count * sizeof(struct ext4_dx_sort_entry));
 977
 978         if (sort_array == NULL) {
 979                 free(entry_buffer);
 980                 return ENOMEM;
 981         }
 982
 983         uint32_t idx = 0;
 984         uint32_t real_size = 0;
 985
 986         /* Initialize hinfo */
 987         struct ext4_hash_info tmp_hinfo;
 988         memcpy(&tmp_hinfo, hinfo, sizeof(struct ext4_hash_info));
 989
 990         /* Load all valid entries to the buffer */
 991         struct ext4_dir_entry_ll *dentry = (void *)old_data_block->data;
 992         uint8_t *entry_buffer_ptr = entry_buffer;
 993         while ((void *)dentry < (void *)(old_data_block->data + block_size)) {
 994                 /* Read only valid entries */
 995                 if (ext4_dir_entry_ll_get_inode(dentry) && dentry->name_length) {
 996                         uint8_t len = ext4_dir_entry_ll_get_name_length(
 997                             &inode_ref->fs->sb, dentry);
 998
 999                         rc = ext4_dir_dx_hash_string(&tmp_hinfo, len,
1000                                                      (char *)dentry->name);
1001                         if (rc != EOK) {
1002                                 free(sort_array);
1003                                 free(entry_buffer);
1004                                 return rc;
1005                         }
1006
1007                         uint32_t rec_len = 8 + len;
1008
1009                         if ((rec_len % 4) != 0)
1010                                 rec_len += 4 - (rec_len % 4);
1011
1012                         memcpy(entry_buffer_ptr, dentry, rec_len);
1013
1014                         sort_array[idx].dentry = entry_buffer_ptr;
1015                         sort_array[idx].rec_len = rec_len;
1016                         sort_array[idx].hash = tmp_hinfo.hash;
1017
1018                         entry_buffer_ptr += rec_len;
1019                         real_size += rec_len;
1020                         idx++;
1021                 }
1022
1023                 dentry = (void *)((uint8_t *)dentry +
1024                                   ext4_dir_entry_ll_get_entry_length(dentry));
1025         }
1026
1027 /* Sort all entries */
1028 #if CONFIG_DIR_INDEX_COMB_SORT
1029         comb_sort(sort_array, idx);
1030 #else
1031         qsort(sort_array, idx, sizeof(struct ext4_dx_sort_entry),
1032               ext4_dir_dx_entry_comparator);
1033 #endif
1034         /* Allocate new block for store the second part of entries */
1035         ext4_fsblk_t new_fblock;
1036         uint32_t new_iblock;
1037         rc = ext4_fs_append_inode_block(inode_ref, &new_fblock, &new_iblock);
1038         if (rc != EOK) {
1039                 free(sort_array);
1040                 free(entry_buffer);
1041                 return rc;
1042         }
1043
1044         /* Load new block */
1045         struct ext4_block new_data_block_tmp;
1046         rc = ext4_block_get(inode_ref->fs->bdev, &new_data_block_tmp,
1047                             new_fblock);
1048         if (rc != EOK) {
1049                 free(sort_array);
1050                 free(entry_buffer);
1051                 return rc;
1052         }
1053
1054         /*
1055          * Distribute entries to two blocks (by size)
1056          * - compute the half
1057          */
1058         uint32_t new_hash = 0;
1059         uint32_t current_size = 0;
1060         uint32_t mid = 0;
1061         uint32_t i;
1062         for (i = 0; i < idx; ++i) {
1063                 if ((current_size + sort_array[i].rec_len) > (block_size / 2)) {
1064                         new_hash = sort_array[i].hash;
1065                         mid = i;
1066                         break;
1067                 }
1068
1069                 current_size += sort_array[i].rec_len;
1070         }
1071
1072         /* Check hash collision */
1073         uint32_t continued = 0;
1074         if (new_hash == sort_array[mid - 1].hash)
1075                 continued = 1;
1076
1077         uint32_t offset = 0;
1078         void *ptr;
1079         struct ext4_sblock *sb = &inode_ref->fs->sb;
1080         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
1081                 block_size -= sizeof(struct ext4_dir_entry_tail);
1082
1083         /* First part - to the old block */
1084         for (i = 0; i < mid; ++i) {
1085                 ptr = old_data_block->data + offset;
1086                 memcpy(ptr, sort_array[i].dentry, sort_array[i].rec_len);
1087
1088                 struct ext4_dir_entry_ll *tmp = ptr;
1089                 if (i < (mid - 1))
1090                         ext4_dir_entry_ll_set_entry_length(
1091                             tmp, sort_array[i].rec_len);
1092                 else
1093                         ext4_dir_entry_ll_set_entry_length(tmp,
1094                                                            block_size - offset);
1095
1096                 offset += sort_array[i].rec_len;
1097         }
1098
1099         /* Second part - to the new block */
1100         offset = 0;
1101         for (i = mid; i < idx; ++i) {
1102                 ptr = new_data_block_tmp.data + offset;
1103                 memcpy(ptr, sort_array[i].dentry, sort_array[i].rec_len);
1104
1105                 struct ext4_dir_entry_ll *tmp = ptr;
1106                 if (i < (idx - 1))
1107                         ext4_dir_entry_ll_set_entry_length(
1108                             tmp, sort_array[i].rec_len);
1109                 else
1110                         ext4_dir_entry_ll_set_entry_length(tmp,
1111                                                            block_size - offset);
1112
1113                 offset += sort_array[i].rec_len;
1114         }
1115
1116         block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
1117
1118         /* Do some steps to finish operation */
1119         sb = &inode_ref->fs->sb;
1120         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
1121                 initialize_dir_tail(EXT4_DIRENT_TAIL(old_data_block->data,
1122                                         block_size));
1123                 initialize_dir_tail(EXT4_DIRENT_TAIL(new_data_block_tmp.data,
1124                                         block_size));
1125         }
1126         ext4_dir_set_checksum(inode_ref,
1127                         (struct ext4_dir_entry_ll *)old_data_block->data);
1128         ext4_dir_set_checksum(inode_ref,
1129                         (struct ext4_dir_entry_ll *)new_data_block_tmp.data);
1130         old_data_block->dirty = true;
1131         new_data_block_tmp.dirty = true;
1132
1133         free(sort_array);
1134         free(entry_buffer);
1135
1136         ext4_dir_dx_insert_entry(inode_ref,
1137                         index_block,
1138                         new_hash + continued, new_iblock);
1139
1140         *new_data_block = new_data_block_tmp;
1141
1142         return EOK;
1143 }
1144
1145 /**@brief  Split index node and maybe some parent nodes in the tree hierarchy.
1146  * @param inode_ref Directory i-node
1147  * @param dx_blocks Array with path from root to leaf node
1148  * @param dx_block  Leaf block to be split if needed
1149  * @return Error code
1150  */
1151 static int
1152 ext4_dir_dx_split_index(struct ext4_inode_ref *inode_ref,
1153                         struct ext4_dir_idx_block *dx_blocks,
1154                         struct ext4_dir_idx_block *dx_block,
1155                         struct ext4_dir_idx_block **new_dx_block)
1156 {
1157         struct ext4_sblock *sb = &inode_ref->fs->sb;
1158         struct ext4_dir_idx_entry *entries;
1159
1160         if (dx_block == dx_blocks)
1161                 entries =
1162                     ((struct ext4_dir_idx_root *)dx_block->block.data)
1163                         ->entries;
1164         else
1165                 entries =
1166                     ((struct ext4_dir_idx_node *)dx_block->block.data)
1167                         ->entries;
1168
1169         struct ext4_dir_idx_countlimit *countlimit =
1170             (struct ext4_dir_idx_countlimit *)entries;
1171
1172         uint16_t leaf_limit = ext4_dir_dx_countlimit_get_limit(countlimit);
1173         uint16_t leaf_count = ext4_dir_dx_countlimit_get_count(countlimit);
1174
1175         /* Check if is necessary to split index block */
1176         if (leaf_limit == leaf_count) {
1177                 size_t levels = dx_block - dx_blocks;
1178
1179                 struct ext4_dir_idx_entry *root_entries =
1180                     ((struct ext4_dir_idx_root *)dx_blocks[0].block.data)
1181                         ->entries;
1182
1183                 struct ext4_dir_idx_countlimit *root_countlimit =
1184                     (struct ext4_dir_idx_countlimit *)root_entries;
1185                 uint16_t root_limit =
1186                     ext4_dir_dx_countlimit_get_limit(root_countlimit);
1187                 uint16_t root_count =
1188                     ext4_dir_dx_countlimit_get_count(root_countlimit);
1189
1190                 /* Linux limitation */
1191                 if ((levels > 0) && (root_limit == root_count))
1192                         return ENOSPC;
1193
1194                 /* Add new block to directory */
1195                 ext4_fsblk_t new_fblock;
1196                 uint32_t new_iblock;
1197                 int rc = ext4_fs_append_inode_block(inode_ref, &new_fblock,
1198                                                     &new_iblock);
1199                 if (rc != EOK)
1200                         return rc;
1201
1202                 /* load new block */
1203                 struct ext4_block new_block;
1204                 rc =
1205                     ext4_block_get(inode_ref->fs->bdev, &new_block, new_fblock);
1206                 if (rc != EOK)
1207                         return rc;
1208
1209                 struct ext4_dir_idx_node *new_node =
1210                     (void *)new_block.data;
1211                 struct ext4_dir_idx_entry *new_entries = new_node->entries;
1212
1213                 memset(&new_node->fake, 0,
1214                        sizeof(struct ext4_fake_dir_entry));
1215
1216                 uint32_t block_size =
1217                     ext4_sb_get_block_size(&inode_ref->fs->sb);
1218
1219                 new_node->fake.entry_length = block_size;
1220
1221                 /* Split leaf node */
1222                 if (levels > 0) {
1223                         uint32_t count_left = leaf_count / 2;
1224                         uint32_t count_right = leaf_count - count_left;
1225                         uint32_t hash_right =
1226                             ext4_dir_dx_entry_get_hash(entries + count_left);
1227
1228                         /* Copy data to new node */
1229                         memcpy((void *)new_entries,
1230                                (void *)(entries + count_left),
1231                                count_right *
1232                                    sizeof(struct ext4_dir_idx_entry));
1233
1234                         /* Initialize new node */
1235                         struct ext4_dir_idx_countlimit *left_countlimit =
1236                             (struct ext4_dir_idx_countlimit *)entries;
1237                         struct ext4_dir_idx_countlimit *right_countlimit =
1238                             (struct ext4_dir_idx_countlimit *)new_entries;
1239
1240                         ext4_dir_dx_countlimit_set_count(left_countlimit,
1241                                                          count_left);
1242                         ext4_dir_dx_countlimit_set_count(right_countlimit,
1243                                                          count_right);
1244
1245                         uint32_t entry_space =
1246                             block_size -
1247                             sizeof(struct ext4_fake_dir_entry);
1248                         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
1249                                 entry_space -= sizeof(struct ext4_dir_idx_tail);
1250
1251                         uint32_t node_limit =
1252                             entry_space / sizeof(struct ext4_dir_idx_entry);
1253
1254                         ext4_dir_dx_countlimit_set_limit(right_countlimit,
1255                                                          node_limit);
1256
1257                         /* Which index block is target for new entry */
1258                         uint32_t position_index =
1259                             (dx_block->position - dx_block->entries);
1260                         if (position_index >= count_left) {
1261                                 ext4_dir_set_dx_checksum(
1262                                                 inode_ref,
1263                                                 (struct ext4_dir_entry_ll *)
1264                                                 dx_block->block.data);
1265                                 dx_block->block.dirty = true;
1266
1267                                 struct ext4_block block_tmp = dx_block->block;
1268
1269                                 dx_block->block = new_block;
1270
1271                                 dx_block->position =
1272                                     new_entries + position_index - count_left;
1273                                 dx_block->entries = new_entries;
1274
1275                                 new_block = block_tmp;
1276                         }
1277
1278                         /* Finally insert new entry */
1279                         ext4_dir_dx_insert_entry(inode_ref,
1280                                                  dx_blocks, hash_right,
1281                                                  new_iblock);
1282                         ext4_dir_set_dx_checksum(inode_ref,
1283                                                 (struct ext4_dir_entry_ll *)
1284                                                         dx_blocks[0].block.data);
1285                         ext4_dir_set_dx_checksum(inode_ref,
1286                                                 (struct ext4_dir_entry_ll *)
1287                                                         dx_blocks[1].block.data);
1288                         dx_blocks[0].block.dirty = true;
1289                         dx_blocks[1].block.dirty = true;
1290
1291                         ext4_dir_set_dx_checksum(inode_ref,
1292                                                 (struct ext4_dir_entry_ll *)
1293                                                         new_block.data);
1294                         new_block.dirty = true;
1295                         return ext4_block_set(inode_ref->fs->bdev, &new_block);
1296                 } else {
1297                         /* Create second level index */
1298
1299                         /* Copy data from root to child block */
1300                         memcpy((void *)new_entries, (void *)entries,
1301                                leaf_count *
1302                                    sizeof(struct ext4_dir_idx_entry));
1303
1304                         struct ext4_dir_idx_countlimit *new_countlimit =
1305                             (struct ext4_dir_idx_countlimit *)new_entries;
1306
1307                         uint32_t entry_space =
1308                             block_size -
1309                             sizeof(struct ext4_fake_dir_entry);
1310                         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
1311                                 entry_space -= sizeof(struct ext4_dir_idx_tail);
1312
1313                         uint32_t node_limit =
1314                             entry_space / sizeof(struct ext4_dir_idx_entry);
1315                         ext4_dir_dx_countlimit_set_limit(new_countlimit,
1316                                                          node_limit);
1317
1318                         /* Set values in root node */
1319                         struct ext4_dir_idx_countlimit
1320                             *new_root_countlimit =
1321                                 (struct ext4_dir_idx_countlimit *)entries;
1322
1323                         ext4_dir_dx_countlimit_set_count(new_root_countlimit,
1324                                                          1);
1325                         ext4_dir_dx_entry_set_block(entries, new_iblock);
1326
1327                         ((struct ext4_dir_idx_root *)dx_blocks[0]
1328                              .block.data)
1329                             ->info.indirect_levels = 1;
1330
1331                         /* Add new entry to the path */
1332                         dx_block = dx_blocks + 1;
1333                         dx_block->position =
1334                             dx_blocks->position - entries + new_entries;
1335                         dx_block->entries = new_entries;
1336                         dx_block->block = new_block;
1337
1338                         *new_dx_block = dx_block;
1339
1340                         ext4_dir_set_dx_checksum(inode_ref,
1341                                                 (struct ext4_dir_entry_ll *)
1342                                                         dx_blocks[0].block.data);
1343                         ext4_dir_set_dx_checksum(inode_ref,
1344                                                 (struct ext4_dir_entry_ll *)
1345                                                         dx_blocks[1].block.data);
1346                         dx_blocks[0].block.dirty = true;
1347                         dx_blocks[1].block.dirty = true;
1348                 }
1349         }
1350
1351         return EOK;
1352 }
1353
1354 int ext4_dir_dx_add_entry(struct ext4_inode_ref *parent,
1355                           struct ext4_inode_ref *child, const char *name)
1356 {
1357         int rc2 = EOK;
1358
1359         /* Get direct block 0 (index root) */
1360         ext4_fsblk_t root_block_addr;
1361         int rc =
1362             ext4_fs_get_inode_data_block_index(parent,
1363                             0, &root_block_addr,
1364                             false);
1365         if (rc != EOK)
1366                 return rc;
1367
1368         struct ext4_fs *fs = parent->fs;
1369         struct ext4_block root_block;
1370
1371         rc = ext4_block_get(fs->bdev, &root_block, root_block_addr);
1372         if (rc != EOK)
1373                 return rc;
1374
1375         if (!ext4_dir_dx_checksum_verify(parent,
1376                         (struct ext4_dir_entry_ll *)root_block.data)) {
1377                 ext4_dbg(DEBUG_DIR_IDX,
1378                          DBG_WARN "HTree root checksum failed."
1379                          "Inode: %" PRIu32", "
1380                          "Block: %" PRIu32"\n",
1381                          parent->index,
1382                          (uint32_t)0);
1383         }
1384
1385         /* Initialize hinfo structure (mainly compute hash) */
1386         uint32_t name_len = strlen(name);
1387         struct ext4_hash_info hinfo;
1388         rc = ext4_dir_hinfo_init(&hinfo, &root_block, &fs->sb, name_len, name);
1389         if (rc != EOK) {
1390                 ext4_block_set(fs->bdev, &root_block);
1391                 return EXT4_ERR_BAD_DX_DIR;
1392         }
1393
1394         /*
1395          * Hardcoded number 2 means maximum height of index
1396          * tree defined in Linux.
1397          */
1398         struct ext4_dir_idx_block dx_blocks[2];
1399         struct ext4_dir_idx_block *dx_block;
1400         struct ext4_dir_idx_block *dx_it;
1401
1402         rc = ext4_dir_dx_get_leaf(&hinfo, parent, &root_block, &dx_block,
1403                                   dx_blocks);
1404         if (rc != EOK) {
1405                 rc = EXT4_ERR_BAD_DX_DIR;
1406                 goto release_index;
1407         }
1408
1409         /* Try to insert to existing data block */
1410         uint32_t leaf_block_idx =
1411             ext4_dir_dx_entry_get_block(dx_block->position);
1412         ext4_fsblk_t leaf_block_addr;
1413         rc = ext4_fs_get_inode_data_block_index(parent, leaf_block_idx,
1414                                                 &leaf_block_addr,
1415                                                 false);
1416         if (rc != EOK)
1417                 goto release_index;
1418
1419         /*
1420          * Check if there is needed to split index node
1421          * (and recursively also parent nodes)
1422          */
1423         rc = ext4_dir_dx_split_index(parent, dx_blocks, dx_block, &dx_block);
1424         if (rc != EOK)
1425                 goto release_target_index;
1426
1427         struct ext4_block target_block;
1428         rc = ext4_block_get(fs->bdev, &target_block, leaf_block_addr);
1429         if (rc != EOK)
1430                 goto release_index;
1431
1432         if (!ext4_dir_checksum_verify(parent,
1433                         (struct ext4_dir_entry_ll *)target_block.data)) {
1434                 ext4_dbg(DEBUG_DIR_IDX,
1435                                 DBG_WARN "HTree leaf block checksum failed."
1436                                 "Inode: %" PRIu32", "
1437                                 "Block: %" PRIu32"\n",
1438                                 parent->index,
1439                                 leaf_block_idx);
1440         }
1441
1442         /* Check if insert operation passed */
1443         rc = ext4_dir_try_insert_entry(&fs->sb, parent, &target_block, child,
1444                                         name, name_len);
1445         if (rc == EOK)
1446                 goto release_target_index;
1447
1448         /* Split entries to two blocks (includes sorting by hash value) */
1449         struct ext4_block new_block;
1450         rc = ext4_dir_dx_split_data(parent, &hinfo, &target_block, dx_block,
1451                                     &new_block);
1452         if (rc != EOK) {
1453                 rc2 = rc;
1454                 goto release_target_index;
1455         }
1456
1457         /* Where to save new entry */
1458         uint32_t new_block_hash =
1459             ext4_dir_dx_entry_get_hash(dx_block->position + 1);
1460         if (hinfo.hash >= new_block_hash)
1461                 rc = ext4_dir_try_insert_entry(&fs->sb, parent, &new_block,
1462                                 child, name, name_len);
1463         else
1464                 rc = ext4_dir_try_insert_entry(&fs->sb, parent, &target_block,
1465                                 child, name, name_len);
1466
1467         /* Cleanup */
1468         rc = ext4_block_set(fs->bdev, &new_block);
1469         if (rc != EOK)
1470                 return rc;
1471
1472 /* Cleanup operations */
1473
1474 release_target_index:
1475         rc2 = rc;
1476
1477         rc = ext4_block_set(fs->bdev, &target_block);
1478         if (rc != EOK)
1479                 return rc;
1480
1481 release_index:
1482         if (rc != EOK)
1483                 rc2 = rc;
1484
1485         dx_it = dx_blocks;
1486
1487         while (dx_it <= dx_block) {
1488                 rc = ext4_block_set(fs->bdev, &dx_it->block);
1489                 if (rc != EOK)
1490                         return rc;
1491
1492                 dx_it++;
1493         }
1494
1495         return rc2;
1496 }
1497
1498 int ext4_dir_dx_reset_parent_inode(struct ext4_inode_ref *dir,
1499                                    uint32_t parent_inode)
1500 {
1501         /* Load block 0, where will be index root located */
1502         ext4_fsblk_t fblock;
1503         int rc = ext4_fs_get_inode_data_block_index(dir, 0, &fblock, false);
1504         if (rc != EOK)
1505                 return rc;
1506
1507         struct ext4_block block;
1508         rc = ext4_block_get(dir->fs->bdev, &block, fblock);
1509         if (rc != EOK)
1510                 return rc;
1511
1512         if (!ext4_dir_dx_checksum_verify(dir,
1513                         (struct ext4_dir_entry_ll *)block.data)) {
1514                 ext4_dbg(DEBUG_DIR_IDX,
1515                          DBG_WARN "HTree root checksum failed."
1516                          "Inode: %" PRIu32", "
1517                          "Block: %" PRIu32"\n",
1518                          dir->index,
1519                          (uint32_t)0);
1520         }
1521
1522         /* Initialize pointers to data structures */
1523         struct ext4_dir_idx_root *root = (void *)block.data;
1524
1525         /* Fill the inode field with a new parent ino. */
1526         ext4_dx_dot_entry_set_inode(&root->dots[1], parent_inode);
1527
1528         ext4_dir_set_dx_checksum(dir,
1529                                 (struct ext4_dir_entry_ll *)
1530                                         block.data);
1531         block.dirty = true;
1532
1533         return ext4_block_set(dir->fs->bdev, &block);
1534 }
1535
1536 /**
1537  * @}
1538  */