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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_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_directory_dx_tail));
 241                 t->checksum = orig_checksum;
 242         }
 243         return checksum;
 244 }
 245
 246 static struct ext4_directory_dx_countlimit *
 247 ext4_dir_dx_get_countlimit(struct ext4_inode_ref *inode_ref,
 248                         struct ext4_directory_entry_ll *dirent,
 249                         int *offset)
 250 {
 251         struct ext4_directory_entry_ll *dp;
 252         struct ext4_directory_dx_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_directory_dx_root *)dirent;
 261                 dp = (struct ext4_directory_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_directory_dx_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_directory_dx_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_directory_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_directory_dx_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_directory_dx_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_directory_dx_entry)) >
 299                                 ext4_sb_get_block_size(sb) -
 300                                 sizeof(struct ext4_directory_dx_tail)) {
 301                         /* There is no space to hold the checksum */
 302                         return true;
 303                 }
 304                 t = (struct ext4_directory_dx_tail *)
 305                         (((struct ext4_directory_dx_entry *)countlimit) + limit);
 306
 307                 if (t->checksum != to_le32(ext4_dir_dx_checksum(inode_ref,
 308                                                                 dirent,
 309                                                                 count_offset,
 310                                                                 count, t)))
 311                         return false;
 312         }
 313         return true;
 314 }
 315
 316
 317 static void
 318 ext4_dir_set_dx_checksum(struct ext4_inode_ref *inode_ref,
 319                         struct ext4_directory_entry_ll *dirent)
 320 {
 321         int count_offset, limit, count;
 322         struct ext4_sblock *sb = &inode_ref->fs->sb;
 323
 324         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
 325                 struct ext4_directory_dx_countlimit *countlimit =
 326                         ext4_dir_dx_get_countlimit(inode_ref, dirent, &count_offset);
 327                 if (!countlimit) {
 328                         /* Directory seems corrupted. */
 329                         return;
 330                 }
 331                 struct ext4_directory_dx_tail *t;
 332                 limit = ext4_dir_dx_countlimit_get_limit(countlimit);
 333                 count = ext4_dir_dx_countlimit_get_count(countlimit);
 334                 if (count_offset + (limit * sizeof(struct ext4_directory_dx_entry)) >
 335                                 ext4_sb_get_block_size(sb) -
 336                                 sizeof(struct ext4_directory_dx_tail)) {
 337                         /* There is no space to hold the checksum */
 338                         return;
 339                 }
 340                 t = (struct ext4_directory_dx_tail *)
 341                         (((struct ext4_directory_dx_entry *)countlimit) + limit);
 342
 343                 t->checksum =
 344                         to_le32(ext4_dir_dx_checksum(inode_ref, dirent, count_offset, count, t));
 345         }
 346 }
 347 #else
 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_directory_dx_root *root = (void *)block.data;
 370         struct ext4_directory_dx_root_info *info = &(root->info);
 371
 372         /* Initialize dot entries */
 373         ext4_dir_write_entry(&dir->fs->sb,
 374                         (struct ext4_directory_entry_ll *)root->dots,
 375                         12,
 376                         dir,
 377                         ".",
 378                         strlen("."));
 379
 380         ext4_dir_write_entry(&dir->fs->sb,
 381                         (struct ext4_directory_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_directory_dx_countlimit *countlimit =
 396             (struct ext4_directory_dx_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_directory_dx_dot_entry) -
 403                                sizeof(struct ext4_directory_dx_root_info);
 404         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 405                 entry_space -= sizeof(struct ext4_directory_dx_tail);
 406
 407         uint16_t root_limit =
 408             entry_space / sizeof(struct ext4_directory_dx_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_directory_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_directory_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_directory_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_directory_dx_entry *entry = root->entries;
 460         ext4_dir_dx_entry_set_block(entry, iblock);
 461
 462         ext4_dir_set_dx_checksum(dir,
 463                         (struct ext4_directory_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_directory_dx_root *root =
 483             (struct ext4_directory_dx_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_directory_dx_dot_entry);
 502         entry_space -= sizeof(struct ext4_directory_dx_root_info);
 503         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 504                 entry_space -= sizeof(struct ext4_directory_dx_tail);
 505         entry_space = entry_space / sizeof(struct ext4_directory_dx_entry);
 506
 507         uint16_t limit = ext4_dir_dx_countlimit_get_limit(
 508             (struct ext4_directory_dx_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_directory_dx_block **dx_block,
 544                                 struct ext4_directory_dx_block *dx_blocks)
 545 {
 546         struct ext4_directory_dx_block *tmp_dx_block = dx_blocks;
 547         struct ext4_directory_dx_root *root =
 548             (struct ext4_directory_dx_root *)root_block->data;
 549         struct ext4_directory_dx_entry *entries =
 550             (struct ext4_directory_dx_entry *)&root->entries;
 551
 552         uint16_t limit = ext4_dir_dx_countlimit_get_limit(
 553             (struct ext4_directory_dx_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_directory_dx_entry *p;
 559         struct ext4_directory_dx_entry *q;
 560         struct ext4_directory_dx_entry *m;
 561         struct ext4_directory_dx_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_directory_dx_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_directory_dx_node *)tmp_block->data)->entries;
 614                 limit = ext4_dir_dx_countlimit_get_limit(
 615                     (struct ext4_directory_dx_countlimit *)entries);
 616
 617                 uint16_t entry_space =
 618                     ext4_sb_get_block_size(&inode_ref->fs->sb) -
 619                     sizeof(struct ext4_fake_directory_entry);
 620
 621                 if (ext4_sb_feature_ro_com(&inode_ref->fs->sb,
 622                                 EXT4_FRO_COM_METADATA_CSUM))
 623                         entry_space -= sizeof(struct ext4_directory_dx_tail);
 624
 625                 entry_space =
 626                     entry_space / sizeof(struct ext4_directory_dx_entry);
 627
 628                 if (limit != entry_space) {
 629                         ext4_block_set(inode_ref->fs->bdev, tmp_block);
 630                         return EXT4_ERR_BAD_DX_DIR;
 631                 }
 632
 633                 if (!ext4_dir_dx_checksum_verify(inode_ref,
 634                                         (struct ext4_directory_entry_ll *)tmp_block->data)) {
 635                         ext4_dbg(DEBUG_DIR_IDX,
 636                                         DBG_WARN "HTree checksum failed."
 637                                         "Inode: %" PRIu32", "
 638                                         "Block: %" PRIu32"\n",
 639                                         inode_ref->index,
 640                                         next_block);
 641                 }
 642
 643                 ++tmp_dx_block;
 644         }
 645
 646         /* Unreachable */
 647         return EOK;
 648 }
 649
 650 /**@brief Check if the the next block would be checked during entry search.
 651  * @param inode_ref Directory i-node
 652  * @param hash      Hash value to check
 653  * @param dx_block  Current block
 654  * @param dx_blocks Array with path from root to leaf node
 655  * @return Standard Error code
 656  */
 657 static int ext4_dir_dx_next_block(struct ext4_inode_ref *inode_ref,
 658                                   uint32_t hash,
 659                                   struct ext4_directory_dx_block *dx_block,
 660                                   struct ext4_directory_dx_block *dx_blocks)
 661 {
 662         uint32_t num_handles = 0;
 663         struct ext4_directory_dx_block *p = dx_block;
 664
 665         /* Try to find data block with next bunch of entries */
 666         while (true) {
 667                 p->position++;
 668                 uint16_t count = ext4_dir_dx_countlimit_get_count(
 669                     (struct ext4_directory_dx_countlimit *)p->entries);
 670
 671                 if (p->position < p->entries + count)
 672                         break;
 673
 674                 if (p == dx_blocks)
 675                         return EOK;
 676
 677                 num_handles++;
 678                 p--;
 679         }
 680
 681         /* Check hash collision (if not occurred - no next block cannot be
 682          * used)*/
 683         uint32_t current_hash = ext4_dir_dx_entry_get_hash(p->position);
 684         if ((hash & 1) == 0) {
 685                 if ((current_hash & ~1) != hash)
 686                         return 0;
 687         }
 688
 689         /* Fill new path */
 690         while (num_handles--) {
 691                 uint32_t block_idx = ext4_dir_dx_entry_get_block(p->position);
 692                 ext4_fsblk_t block_addr;
 693
 694                 int rc = ext4_fs_get_inode_data_block_index(
 695                     inode_ref, block_idx, &block_addr, false);
 696                 if (rc != EOK)
 697                         return rc;
 698
 699                 struct ext4_block block;
 700                 rc = ext4_block_get(inode_ref->fs->bdev, &block, block_addr);
 701                 if (rc != EOK)
 702                         return rc;
 703
 704                 if (!ext4_dir_dx_checksum_verify(inode_ref,
 705                                         (struct ext4_directory_entry_ll *)block.data)) {
 706                         ext4_dbg(DEBUG_DIR_IDX,
 707                                         DBG_WARN "HTree checksum failed."
 708                                         "Inode: %" PRIu32", "
 709                                         "Block: %" PRIu32"\n",
 710                                         inode_ref->index,
 711                                         block_idx);
 712                 }
 713
 714                 p++;
 715
 716                 /* Don't forget to put old block (prevent memory leak) */
 717                 rc = ext4_block_set(inode_ref->fs->bdev, &p->block);
 718                 if (rc != EOK)
 719                         return rc;
 720
 721                 memcpy(&p->block, &block, sizeof(block));
 722                 p->entries =
 723                     ((struct ext4_directory_dx_node *)block.data)->entries;
 724                 p->position = p->entries;
 725         }
 726
 727         return ENOENT;
 728 }
 729
 730 int ext4_dir_dx_find_entry(struct ext4_directory_search_result *result,
 731                            struct ext4_inode_ref *inode_ref, size_t name_len,
 732                            const char *name)
 733 {
 734         /* Load direct block 0 (index root) */
 735         ext4_fsblk_t root_block_addr;
 736         int rc2;
 737         int rc =
 738             ext4_fs_get_inode_data_block_index(inode_ref,
 739                             0, &root_block_addr, false);
 740         if (rc != EOK)
 741                 return rc;
 742
 743         struct ext4_fs *fs = inode_ref->fs;
 744
 745         struct ext4_block root_block;
 746         rc = ext4_block_get(fs->bdev, &root_block, root_block_addr);
 747         if (rc != EOK)
 748                 return rc;
 749
 750         if (!ext4_dir_dx_checksum_verify(inode_ref,
 751                                 (struct ext4_directory_entry_ll *)root_block.data)) {
 752                 ext4_dbg(DEBUG_DIR_IDX,
 753                          DBG_WARN "HTree root checksum failed."
 754                          "Inode: %" PRIu32", "
 755                          "Block: %" PRIu32"\n",
 756                          inode_ref->index,
 757                          0);
 758         }
 759
 760         /* Initialize hash info (compute hash value) */
 761         struct ext4_hash_info hinfo;
 762         rc = ext4_dir_hinfo_init(&hinfo, &root_block, &fs->sb, name_len, name);
 763         if (rc != EOK) {
 764                 ext4_block_set(fs->bdev, &root_block);
 765                 return EXT4_ERR_BAD_DX_DIR;
 766         }
 767
 768         /*
 769          * Hardcoded number 2 means maximum height of index tree,
 770          * specified in the Linux driver.
 771          */
 772         struct ext4_directory_dx_block dx_blocks[2];
 773         struct ext4_directory_dx_block *dx_block;
 774         struct ext4_directory_dx_block *tmp;
 775
 776         rc = ext4_dir_dx_get_leaf(&hinfo, inode_ref, &root_block, &dx_block,
 777                                   dx_blocks);
 778         if (rc != EOK) {
 779                 ext4_block_set(fs->bdev, &root_block);
 780                 return EXT4_ERR_BAD_DX_DIR;
 781         }
 782
 783         do {
 784                 /* Load leaf block */
 785                 uint32_t leaf_block_idx =
 786                     ext4_dir_dx_entry_get_block(dx_block->position);
 787                 ext4_fsblk_t leaf_block_addr;
 788
 789                 rc = ext4_fs_get_inode_data_block_index(
 790                     inode_ref, leaf_block_idx, &leaf_block_addr,
 791                     false);
 792                 if (rc != EOK)
 793                         goto cleanup;
 794
 795                 struct ext4_block leaf_block;
 796                 rc = ext4_block_get(fs->bdev, &leaf_block, leaf_block_addr);
 797                 if (rc != EOK)
 798                         goto cleanup;
 799
 800                 if (!ext4_dir_checksum_verify(inode_ref,
 801                                 (struct ext4_directory_entry_ll *)leaf_block.data)) {
 802                         ext4_dbg(DEBUG_DIR_IDX,
 803                                  DBG_WARN "HTree leaf block checksum failed."
 804                                  "Inode: %" PRIu32", "
 805                                  "Block: %" PRIu32"\n",
 806                                  inode_ref->index,
 807                                  leaf_block_idx);
 808                 }
 809
 810                 /* Linear search inside block */
 811                 struct ext4_directory_entry_ll *res_dentry;
 812                 rc = ext4_dir_find_in_block(&leaf_block, &fs->sb, name_len,
 813                                             name, &res_dentry);
 814
 815                 /* Found => return it */
 816                 if (rc == EOK) {
 817                         result->block = leaf_block;
 818                         result->dentry = res_dentry;
 819                         goto cleanup;
 820                 }
 821
 822                 /* Not found, leave untouched */
 823                 rc2 = ext4_block_set(fs->bdev, &leaf_block);
 824                 if (rc2 != EOK)
 825                         goto cleanup;
 826
 827                 if (rc != ENOENT)
 828                         goto cleanup;
 829
 830                 /* check if the next block could be checked */
 831                 rc = ext4_dir_dx_next_block(inode_ref, hinfo.hash, dx_block,
 832                                             &dx_blocks[0]);
 833                 if (rc < 0)
 834                         goto cleanup;
 835         } while (rc == ENOENT);
 836
 837         /* Entry not found */
 838         rc = ENOENT;
 839
 840 cleanup:
 841         /* The whole path must be released (preventing memory leak) */
 842         tmp = dx_blocks;
 843
 844         while (tmp <= dx_block) {
 845                 rc2 = ext4_block_set(fs->bdev, &tmp->block);
 846                 if (rc == EOK && rc2 != EOK)
 847                         rc = rc2;
 848                 ++tmp;
 849         }
 850
 851         return rc;
 852 }
 853
 854 #if CONFIG_DIR_INDEX_COMB_SORT
 855 #define SWAP_ENTRY(se1, se2)                                                   \
 856         do {                                                                   \
 857                 struct ext4_dx_sort_entry tmp = se1;                           \
 858                 se1 = se2;                                                     \
 859                 se2 = tmp;                                                     \
 860         \
 861 } while (0)
 862
 863 static void comb_sort(struct ext4_dx_sort_entry *se, uint32_t count)
 864 {
 865         struct ext4_dx_sort_entry *p, *q, *top = se + count - 1;
 866         bool more;
 867         /* Combsort */
 868         while (count > 2) {
 869                 count = (count * 10) / 13;
 870                 if (count - 9 < 2)
 871                         count = 11;
 872                 for (p = top, q = p - count; q >= se; p--, q--)
 873                         if (p->hash < q->hash)
 874                                 SWAP_ENTRY(*p, *q);
 875         }
 876         /* Bubblesort */
 877         do {
 878                 more = 0;
 879                 q = top;
 880                 while (q-- > se) {
 881                         if (q[1].hash >= q[0].hash)
 882                                 continue;
 883                         SWAP_ENTRY(*(q + 1), *q);
 884                         more = 1;
 885                 }
 886         } while (more);
 887 }
 888 #else
 889
 890 /**@brief  Compare function used to pass in quicksort implementation.
 891  *         It can compare two entries by hash value.
 892  * @param arg1  First entry
 893  * @param arg2  Second entry
 894  * @param dummy Unused parameter, can be NULL
 895  *
 896  * @return Classic compare result
 897  *         (0: equal, -1: arg1 < arg2, 1: arg1 > arg2)
 898  */
 899 static int ext4_dir_dx_entry_comparator(const void *arg1, const void *arg2)
 900 {
 901         struct ext4_dx_sort_entry *entry1 = (void *)arg1;
 902         struct ext4_dx_sort_entry *entry2 = (void *)arg2;
 903
 904         if (entry1->hash == entry2->hash)
 905                 return 0;
 906
 907         if (entry1->hash < entry2->hash)
 908                 return -1;
 909         else
 910                 return 1;
 911 }
 912 #endif
 913
 914 /**@brief  Insert new index entry to block.
 915  *         Note that space for new entry must be checked by caller.
 916  * @param inode_ref   Directory i-node
 917  * @param index_block Block where to insert new entry
 918  * @param hash        Hash value covered by child node
 919  * @param iblock      Logical number of child block
 920  *
 921  */
 922 static void
 923 ext4_dir_dx_insert_entry(struct ext4_inode_ref *inode_ref __unused,
 924                          struct ext4_directory_dx_block *index_block,
 925                          uint32_t hash, uint32_t iblock)
 926 {
 927         struct ext4_directory_dx_entry *old_index_entry = index_block->position;
 928         struct ext4_directory_dx_entry *new_index_entry = old_index_entry + 1;
 929
 930         struct ext4_directory_dx_countlimit *countlimit =
 931             (struct ext4_directory_dx_countlimit *)index_block->entries;
 932         uint32_t count = ext4_dir_dx_countlimit_get_count(countlimit);
 933
 934         struct ext4_directory_dx_entry *start_index = index_block->entries;
 935         size_t bytes =
 936             (uint8_t *)(start_index + count) - (uint8_t *)(new_index_entry);
 937
 938         memmove(new_index_entry + 1, new_index_entry, bytes);
 939
 940         ext4_dir_dx_entry_set_block(new_index_entry, iblock);
 941         ext4_dir_dx_entry_set_hash(new_index_entry, hash);
 942
 943         ext4_dir_dx_countlimit_set_count(countlimit, count + 1);
 944
 945         ext4_dir_set_dx_checksum(inode_ref,
 946                         (struct ext4_directory_entry_ll *)index_block->block.data);
 947         index_block->block.dirty = true;
 948 }
 949
 950 /**@brief Split directory entries to two parts preventing node overflow.
 951  * @param inode_ref      Directory i-node
 952  * @param hinfo          Hash info
 953  * @param old_data_block Block with data to be split
 954  * @param index_block    Block where index entries are located
 955  * @param new_data_block Output value for newly allocated data block
 956  */
 957 static int ext4_dir_dx_split_data(struct ext4_inode_ref *inode_ref,
 958                                   struct ext4_hash_info *hinfo,
 959                                   struct ext4_block *old_data_block,
 960                                   struct ext4_directory_dx_block *index_block,
 961                                   struct ext4_block *new_data_block)
 962 {
 963         int rc = EOK;
 964
 965         /* Allocate buffer for directory entries */
 966         uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
 967
 968         uint8_t *entry_buffer = malloc(block_size);
 969         if (entry_buffer == NULL)
 970                 return ENOMEM;
 971
 972         /* dot entry has the smallest size available */
 973         uint32_t max_entry_count =
 974             block_size / sizeof(struct ext4_directory_dx_dot_entry);
 975
 976         /* Allocate sort entry */
 977         struct ext4_dx_sort_entry *sort_array =
 978             malloc(max_entry_count * sizeof(struct ext4_dx_sort_entry));
 979
 980         if (sort_array == NULL) {
 981                 free(entry_buffer);
 982                 return ENOMEM;
 983         }
 984
 985         uint32_t idx = 0;
 986         uint32_t real_size = 0;
 987
 988         /* Initialize hinfo */
 989         struct ext4_hash_info tmp_hinfo;
 990         memcpy(&tmp_hinfo, hinfo, sizeof(struct ext4_hash_info));
 991
 992         /* Load all valid entries to the buffer */
 993         struct ext4_directory_entry_ll *dentry = (void *)old_data_block->data;
 994         uint8_t *entry_buffer_ptr = entry_buffer;
 995         while ((void *)dentry < (void *)(old_data_block->data + block_size)) {
 996                 /* Read only valid entries */
 997                 if (ext4_dir_entry_ll_get_inode(dentry) &&
 998                     dentry->name_length) {
 999                         uint8_t len = ext4_dir_entry_ll_get_name_length(
1000                             &inode_ref->fs->sb, dentry);
1001
1002                         rc = ext4_dir_dx_hash_string(&tmp_hinfo, len,
1003                                                      (char *)dentry->name);
1004                         if (rc != EOK) {
1005                                 free(sort_array);
1006                                 free(entry_buffer);
1007                                 return rc;
1008                         }
1009
1010                         uint32_t rec_len = 8 + len;
1011
1012                         if ((rec_len % 4) != 0)
1013                                 rec_len += 4 - (rec_len % 4);
1014
1015                         memcpy(entry_buffer_ptr, dentry, rec_len);
1016
1017                         sort_array[idx].dentry = entry_buffer_ptr;
1018                         sort_array[idx].rec_len = rec_len;
1019                         sort_array[idx].hash = tmp_hinfo.hash;
1020
1021                         entry_buffer_ptr += rec_len;
1022                         real_size += rec_len;
1023                         idx++;
1024                 }
1025
1026                 dentry = (void *)((uint8_t *)dentry +
1027                                   ext4_dir_entry_ll_get_entry_length(dentry));
1028         }
1029
1030 /* Sort all entries */
1031 #if CONFIG_DIR_INDEX_COMB_SORT
1032         comb_sort(sort_array, idx);
1033 #else
1034         qsort(sort_array, idx, sizeof(struct ext4_dx_sort_entry),
1035               ext4_dir_dx_entry_comparator);
1036 #endif
1037         /* Allocate new block for store the second part of entries */
1038         ext4_fsblk_t new_fblock;
1039         uint32_t new_iblock;
1040         rc = ext4_fs_append_inode_block(inode_ref, &new_fblock, &new_iblock);
1041         if (rc != EOK) {
1042                 free(sort_array);
1043                 free(entry_buffer);
1044                 return rc;
1045         }
1046
1047         /* Load new block */
1048         struct ext4_block new_data_block_tmp;
1049         rc = ext4_block_get(inode_ref->fs->bdev, &new_data_block_tmp,
1050                             new_fblock);
1051         if (rc != EOK) {
1052                 free(sort_array);
1053                 free(entry_buffer);
1054                 return rc;
1055         }
1056
1057         /*
1058          * Distribute entries to two blocks (by size)
1059          * - compute the half
1060          */
1061         uint32_t new_hash = 0;
1062         uint32_t current_size = 0;
1063         uint32_t mid = 0;
1064         uint32_t i;
1065         for (i = 0; i < idx; ++i) {
1066                 if ((current_size + sort_array[i].rec_len) > (block_size / 2)) {
1067                         new_hash = sort_array[i].hash;
1068                         mid = i;
1069                         break;
1070                 }
1071
1072                 current_size += sort_array[i].rec_len;
1073         }
1074
1075         /* Check hash collision */
1076         uint32_t continued = 0;
1077         if (new_hash == sort_array[mid - 1].hash)
1078                 continued = 1;
1079
1080         uint32_t offset = 0;
1081         void *ptr;
1082         struct ext4_sblock *sb = &inode_ref->fs->sb;
1083         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
1084                 block_size -= sizeof(struct ext4_directory_entry_tail);
1085
1086         /* First part - to the old block */
1087         for (i = 0; i < mid; ++i) {
1088                 ptr = old_data_block->data + offset;
1089                 memcpy(ptr, sort_array[i].dentry, sort_array[i].rec_len);
1090
1091                 struct ext4_directory_entry_ll *tmp = ptr;
1092                 if (i < (mid - 1))
1093                         ext4_dir_entry_ll_set_entry_length(
1094                             tmp, sort_array[i].rec_len);
1095                 else
1096                         ext4_dir_entry_ll_set_entry_length(tmp,
1097                                                            block_size - offset);
1098
1099                 offset += sort_array[i].rec_len;
1100         }
1101
1102         /* Second part - to the new block */
1103         offset = 0;
1104         for (i = mid; i < idx; ++i) {
1105                 ptr = new_data_block_tmp.data + offset;
1106                 memcpy(ptr, sort_array[i].dentry, sort_array[i].rec_len);
1107
1108                 struct ext4_directory_entry_ll *tmp = ptr;
1109                 if (i < (idx - 1))
1110                         ext4_dir_entry_ll_set_entry_length(
1111                             tmp, sort_array[i].rec_len);
1112                 else
1113                         ext4_dir_entry_ll_set_entry_length(tmp,
1114                                                            block_size - offset);
1115
1116                 offset += sort_array[i].rec_len;
1117         }
1118
1119         block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
1120
1121         /* Do some steps to finish operation */
1122         sb = &inode_ref->fs->sb;
1123         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
1124                 initialize_dir_tail(EXT4_DIRENT_TAIL(old_data_block->data,
1125                                         block_size));
1126                 initialize_dir_tail(EXT4_DIRENT_TAIL(new_data_block_tmp.data,
1127                                         block_size));
1128         }
1129         ext4_dir_set_checksum(inode_ref,
1130                         (struct ext4_directory_entry_ll *)old_data_block->data);
1131         ext4_dir_set_checksum(inode_ref,
1132                         (struct ext4_directory_entry_ll *)new_data_block_tmp.data);
1133         old_data_block->dirty = true;
1134         new_data_block_tmp.dirty = true;
1135
1136         free(sort_array);
1137         free(entry_buffer);
1138
1139         ext4_dir_dx_insert_entry(inode_ref,
1140                         index_block,
1141                         new_hash + continued, new_iblock);
1142
1143         *new_data_block = new_data_block_tmp;
1144
1145         return EOK;
1146 }
1147
1148 /**@brief  Split index node and maybe some parent nodes in the tree hierarchy.
1149  * @param inode_ref Directory i-node
1150  * @param dx_blocks Array with path from root to leaf node
1151  * @param dx_block  Leaf block to be split if needed
1152  * @return Error code
1153  */
1154 static int
1155 ext4_dir_dx_split_index(struct ext4_inode_ref *inode_ref,
1156                         struct ext4_directory_dx_block *dx_blocks,
1157                         struct ext4_directory_dx_block *dx_block,
1158                         struct ext4_directory_dx_block **new_dx_block)
1159 {
1160         struct ext4_sblock *sb = &inode_ref->fs->sb;
1161         struct ext4_directory_dx_entry *entries;
1162
1163         if (dx_block == dx_blocks)
1164                 entries =
1165                     ((struct ext4_directory_dx_root *)dx_block->block.data)
1166                         ->entries;
1167         else
1168                 entries =
1169                     ((struct ext4_directory_dx_node *)dx_block->block.data)
1170                         ->entries;
1171
1172         struct ext4_directory_dx_countlimit *countlimit =
1173             (struct ext4_directory_dx_countlimit *)entries;
1174
1175         uint16_t leaf_limit = ext4_dir_dx_countlimit_get_limit(countlimit);
1176         uint16_t leaf_count = ext4_dir_dx_countlimit_get_count(countlimit);
1177
1178         /* Check if is necessary to split index block */
1179         if (leaf_limit == leaf_count) {
1180                 size_t levels = dx_block - dx_blocks;
1181
1182                 struct ext4_directory_dx_entry *root_entries =
1183                     ((struct ext4_directory_dx_root *)dx_blocks[0].block.data)
1184                         ->entries;
1185
1186                 struct ext4_directory_dx_countlimit *root_countlimit =
1187                     (struct ext4_directory_dx_countlimit *)root_entries;
1188                 uint16_t root_limit =
1189                     ext4_dir_dx_countlimit_get_limit(root_countlimit);
1190                 uint16_t root_count =
1191                     ext4_dir_dx_countlimit_get_count(root_countlimit);
1192
1193                 /* Linux limitation */
1194                 if ((levels > 0) && (root_limit == root_count))
1195                         return ENOSPC;
1196
1197                 /* Add new block to directory */
1198                 ext4_fsblk_t new_fblock;
1199                 uint32_t new_iblock;
1200                 int rc = ext4_fs_append_inode_block(inode_ref, &new_fblock,
1201                                                     &new_iblock);
1202                 if (rc != EOK)
1203                         return rc;
1204
1205                 /* load new block */
1206                 struct ext4_block new_block;
1207                 rc =
1208                     ext4_block_get(inode_ref->fs->bdev, &new_block, new_fblock);
1209                 if (rc != EOK)
1210                         return rc;
1211
1212                 struct ext4_directory_dx_node *new_node =
1213                     (void *)new_block.data;
1214                 struct ext4_directory_dx_entry *new_entries = new_node->entries;
1215
1216                 memset(&new_node->fake, 0,
1217                        sizeof(struct ext4_fake_directory_entry));
1218
1219                 uint32_t block_size =
1220                     ext4_sb_get_block_size(&inode_ref->fs->sb);
1221
1222                 new_node->fake.entry_length = block_size;
1223
1224                 /* Split leaf node */
1225                 if (levels > 0) {
1226                         uint32_t count_left = leaf_count / 2;
1227                         uint32_t count_right = leaf_count - count_left;
1228                         uint32_t hash_right =
1229                             ext4_dir_dx_entry_get_hash(entries + count_left);
1230
1231                         /* Copy data to new node */
1232                         memcpy((void *)new_entries,
1233                                (void *)(entries + count_left),
1234                                count_right *
1235                                    sizeof(struct ext4_directory_dx_entry));
1236
1237                         /* Initialize new node */
1238                         struct ext4_directory_dx_countlimit *left_countlimit =
1239                             (struct ext4_directory_dx_countlimit *)entries;
1240                         struct ext4_directory_dx_countlimit *right_countlimit =
1241                             (struct ext4_directory_dx_countlimit *)new_entries;
1242
1243                         ext4_dir_dx_countlimit_set_count(left_countlimit,
1244                                                          count_left);
1245                         ext4_dir_dx_countlimit_set_count(right_countlimit,
1246                                                          count_right);
1247
1248                         uint32_t entry_space =
1249                             block_size -
1250                             sizeof(struct ext4_fake_directory_entry);
1251                         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
1252                                 entry_space -= sizeof(struct ext4_directory_dx_tail);
1253
1254                         uint32_t node_limit =
1255                             entry_space / sizeof(struct ext4_directory_dx_entry);
1256
1257                         ext4_dir_dx_countlimit_set_limit(right_countlimit,
1258                                                          node_limit);
1259
1260                         /* Which index block is target for new entry */
1261                         uint32_t position_index =
1262                             (dx_block->position - dx_block->entries);
1263                         if (position_index >= count_left) {
1264                                 ext4_dir_set_dx_checksum(
1265                                                 inode_ref,
1266                                                 (struct ext4_directory_entry_ll *)
1267                                                 dx_block->block.data);
1268                                 dx_block->block.dirty = true;
1269
1270                                 struct ext4_block block_tmp = dx_block->block;
1271
1272                                 dx_block->block = new_block;
1273
1274                                 dx_block->position =
1275                                     new_entries + position_index - count_left;
1276                                 dx_block->entries = new_entries;
1277
1278                                 new_block = block_tmp;
1279                         }
1280
1281                         /* Finally insert new entry */
1282                         ext4_dir_dx_insert_entry(inode_ref,
1283                                                  dx_blocks, hash_right,
1284                                                  new_iblock);
1285                         ext4_dir_set_dx_checksum(inode_ref,
1286                                                 (struct ext4_directory_entry_ll *)
1287                                                         dx_blocks[0].block.data);
1288                         ext4_dir_set_dx_checksum(inode_ref,
1289                                                 (struct ext4_directory_entry_ll *)
1290                                                         dx_blocks[1].block.data);
1291                         dx_blocks[0].block.dirty = true;
1292                         dx_blocks[1].block.dirty = true;
1293
1294                         ext4_dir_set_dx_checksum(inode_ref,
1295                                                 (struct ext4_directory_entry_ll *)
1296                                                         new_block.data);
1297                         new_block.dirty = true;
1298                         return ext4_block_set(inode_ref->fs->bdev, &new_block);
1299                 } else {
1300                         /* Create second level index */
1301
1302                         /* Copy data from root to child block */
1303                         memcpy((void *)new_entries, (void *)entries,
1304                                leaf_count *
1305                                    sizeof(struct ext4_directory_dx_entry));
1306
1307                         struct ext4_directory_dx_countlimit *new_countlimit =
1308                             (struct ext4_directory_dx_countlimit *)new_entries;
1309
1310                         uint32_t entry_space =
1311                             block_size -
1312                             sizeof(struct ext4_fake_directory_entry);
1313                         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
1314                                 entry_space -= sizeof(struct ext4_directory_dx_tail);
1315
1316                         uint32_t node_limit =
1317                             entry_space / sizeof(struct ext4_directory_dx_entry);
1318                         ext4_dir_dx_countlimit_set_limit(new_countlimit,
1319                                                          node_limit);
1320
1321                         /* Set values in root node */
1322                         struct ext4_directory_dx_countlimit
1323                             *new_root_countlimit =
1324                                 (struct ext4_directory_dx_countlimit *)entries;
1325
1326                         ext4_dir_dx_countlimit_set_count(new_root_countlimit,
1327                                                          1);
1328                         ext4_dir_dx_entry_set_block(entries, new_iblock);
1329
1330                         ((struct ext4_directory_dx_root *)dx_blocks[0]
1331                              .block.data)
1332                             ->info.indirect_levels = 1;
1333
1334                         /* Add new entry to the path */
1335                         dx_block = dx_blocks + 1;
1336                         dx_block->position =
1337                             dx_blocks->position - entries + new_entries;
1338                         dx_block->entries = new_entries;
1339                         dx_block->block = new_block;
1340
1341                         *new_dx_block = dx_block;
1342
1343                         ext4_dir_set_dx_checksum(inode_ref,
1344                                                 (struct ext4_directory_entry_ll *)
1345                                                         dx_blocks[0].block.data);
1346                         ext4_dir_set_dx_checksum(inode_ref,
1347                                                 (struct ext4_directory_entry_ll *)
1348                                                         dx_blocks[1].block.data);
1349                         dx_blocks[0].block.dirty = true;
1350                         dx_blocks[1].block.dirty = true;
1351                 }
1352         }
1353
1354         return EOK;
1355 }
1356
1357 int ext4_dir_dx_add_entry(struct ext4_inode_ref *parent,
1358                           struct ext4_inode_ref *child, const char *name)
1359 {
1360         int rc2 = EOK;
1361
1362         /* Get direct block 0 (index root) */
1363         ext4_fsblk_t root_block_addr;
1364         int rc =
1365             ext4_fs_get_inode_data_block_index(parent,
1366                             0, &root_block_addr,
1367                             false);
1368         if (rc != EOK)
1369                 return rc;
1370
1371         struct ext4_fs *fs = parent->fs;
1372         struct ext4_block root_block;
1373
1374         rc = ext4_block_get(fs->bdev, &root_block, root_block_addr);
1375         if (rc != EOK)
1376                 return rc;
1377
1378         if (!ext4_dir_dx_checksum_verify(parent,
1379                         (struct ext4_directory_entry_ll *)root_block.data)) {
1380                 ext4_dbg(DEBUG_DIR_IDX,
1381                          DBG_WARN "HTree root checksum failed."
1382                          "Inode: %" PRIu32", "
1383                          "Block: %" PRIu32"\n",
1384                          parent->index,
1385                          0);
1386         }
1387
1388         /* Initialize hinfo structure (mainly compute hash) */
1389         uint32_t name_len = strlen(name);
1390         struct ext4_hash_info hinfo;
1391         rc = ext4_dir_hinfo_init(&hinfo, &root_block, &fs->sb, name_len, name);
1392         if (rc != EOK) {
1393                 ext4_block_set(fs->bdev, &root_block);
1394                 return EXT4_ERR_BAD_DX_DIR;
1395         }
1396
1397         /*
1398          * Hardcoded number 2 means maximum height of index
1399          * tree defined in Linux.
1400          */
1401         struct ext4_directory_dx_block dx_blocks[2];
1402         struct ext4_directory_dx_block *dx_block;
1403         struct ext4_directory_dx_block *dx_it;
1404
1405         rc = ext4_dir_dx_get_leaf(&hinfo, parent, &root_block, &dx_block,
1406                                   dx_blocks);
1407         if (rc != EOK) {
1408                 rc = EXT4_ERR_BAD_DX_DIR;
1409                 goto release_index;
1410         }
1411
1412         /* Try to insert to existing data block */
1413         uint32_t leaf_block_idx =
1414             ext4_dir_dx_entry_get_block(dx_block->position);
1415         ext4_fsblk_t leaf_block_addr;
1416         rc = ext4_fs_get_inode_data_block_index(parent, leaf_block_idx,
1417                                                 &leaf_block_addr,
1418                                                 false);
1419         if (rc != EOK)
1420                 goto release_index;
1421
1422         /*
1423          * Check if there is needed to split index node
1424          * (and recursively also parent nodes)
1425          */
1426         rc = ext4_dir_dx_split_index(parent, dx_blocks, dx_block, &dx_block);
1427         if (rc != EOK)
1428                 goto release_target_index;
1429
1430         struct ext4_block target_block;
1431         rc = ext4_block_get(fs->bdev, &target_block, leaf_block_addr);
1432         if (rc != EOK)
1433                 goto release_index;
1434
1435         if (!ext4_dir_checksum_verify(parent,
1436                         (struct ext4_directory_entry_ll *)target_block.data)) {
1437                 ext4_dbg(DEBUG_DIR_IDX,
1438                                 DBG_WARN "HTree leaf block checksum failed."
1439                                 "Inode: %" PRIu32", "
1440                                 "Block: %" PRIu32"\n",
1441                                 parent->index,
1442                                 leaf_block_idx);
1443         }
1444
1445         /* Check if insert operation passed */
1446         rc = ext4_dir_try_insert_entry(&fs->sb, parent, &target_block, child, name,
1447                                        name_len);
1448         if (rc == EOK)
1449                 goto release_target_index;
1450
1451         /* Split entries to two blocks (includes sorting by hash value) */
1452         struct ext4_block new_block;
1453         rc = ext4_dir_dx_split_data(parent, &hinfo, &target_block, dx_block,
1454                                     &new_block);
1455         if (rc != EOK) {
1456                 rc2 = rc;
1457                 goto release_target_index;
1458         }
1459
1460         /* Where to save new entry */
1461         uint32_t new_block_hash =
1462             ext4_dir_dx_entry_get_hash(dx_block->position + 1);
1463         if (hinfo.hash >= new_block_hash)
1464                 rc = ext4_dir_try_insert_entry(&fs->sb, parent, &new_block, child, name,
1465                                                name_len);
1466         else
1467                 rc = ext4_dir_try_insert_entry(&fs->sb, parent, &target_block, child,
1468                                                name, name_len);
1469
1470         /* Cleanup */
1471         rc = ext4_block_set(fs->bdev, &new_block);
1472         if (rc != EOK)
1473                 return rc;
1474
1475 /* Cleanup operations */
1476
1477 release_target_index:
1478         rc2 = rc;
1479
1480         rc = ext4_block_set(fs->bdev, &target_block);
1481         if (rc != EOK)
1482                 return rc;
1483
1484 release_index:
1485         if (rc != EOK)
1486                 rc2 = rc;
1487
1488         dx_it = dx_blocks;
1489
1490         while (dx_it <= dx_block) {
1491                 rc = ext4_block_set(fs->bdev, &dx_it->block);
1492                 if (rc != EOK)
1493                         return rc;
1494
1495                 dx_it++;
1496         }
1497
1498         return rc2;
1499 }
1500
1501 int ext4_dir_dx_reset_parent_inode(struct ext4_inode_ref *dir,
1502                                    uint32_t parent_inode)
1503 {
1504         /* Load block 0, where will be index root located */
1505         ext4_fsblk_t fblock;
1506         int rc = ext4_fs_get_inode_data_block_index(dir, 0, &fblock, false);
1507         if (rc != EOK)
1508                 return rc;
1509
1510         struct ext4_block block;
1511         rc = ext4_block_get(dir->fs->bdev, &block, fblock);
1512         if (rc != EOK)
1513                 return rc;
1514
1515         if (!ext4_dir_dx_checksum_verify(dir,
1516                         (struct ext4_directory_entry_ll *)block.data)) {
1517                 ext4_dbg(DEBUG_DIR_IDX,
1518                          DBG_WARN "HTree root checksum failed."
1519                          "Inode: %" PRIu32", "
1520                          "Block: %" PRIu32"\n",
1521                          dir->index,
1522                          0);
1523         }
1524
1525         /* Initialize pointers to data structures */
1526         struct ext4_directory_dx_root *root = (void *)block.data;
1527
1528         /* Fill the inode field with a new parent ino. */
1529         ext4_dx_dot_entry_set_inode(&root->dots[1], parent_inode);
1530
1531         ext4_dir_set_dx_checksum(dir,
1532                                 (struct ext4_directory_entry_ll *)
1533                                         block.data);
1534         block.dirty = true;
1535
1536         return ext4_block_set(dir->fs->bdev, &block);
1537 }
1538
1539 /**
1540  * @}
1541  */