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_crc32c.h"
  44 #include "ext4_hash.h"
  45
  46 #include <string.h>
  47 #include <stdlib.h>
  48
  49 /**@brief Get hash version used in directory index.
  50  * @param root_info Pointer to root info structure of index
  51  * @return Hash algorithm version
  52  */
  53 static inline uint8_t ext4_dir_dx_root_info_get_hash_version(
  54     struct ext4_directory_dx_root_info *root_info)
  55 {
  56         return root_info->hash_version;
  57 }
  58
  59 /**@brief Set hash version, that will be used in directory index.
  60  * @param root_info Pointer to root info structure of index
  61  * @param v Hash algorithm version
  62  */
  63 static inline void ext4_dir_dx_root_info_set_hash_version(
  64     struct ext4_directory_dx_root_info *root_info, uint8_t v)
  65 {
  66         root_info->hash_version = v;
  67 }
  68
  69 /**@brief Get length of root_info structure in bytes.
  70  * @param root_info Pointer to root info structure of index
  71  * @return Length of the structure
  72  */
  73 static inline uint8_t ext4_dir_dx_root_info_get_info_length(
  74     struct ext4_directory_dx_root_info *root_info)
  75 {
  76         return root_info->info_length;
  77 }
  78
  79 /**@brief Set length of root_info structure in bytes.
  80  * @param root_info   Pointer to root info structure of index
  81  * @param info_length Length of the structure
  82  */
  83 static inline void ext4_dir_dx_root_info_set_info_length(
  84     struct ext4_directory_dx_root_info *root_info, uint8_t len)
  85 {
  86         root_info->info_length = len;
  87 }
  88
  89 /**@brief Get number of indirect levels of HTree.
  90  * @param root_info Pointer to root info structure of index
  91  * @return Height of HTree (actually only 0 or 1)
  92  */
  93 static inline uint8_t ext4_dir_dx_root_info_get_indirect_levels(
  94     struct ext4_directory_dx_root_info *root_info)
  95 {
  96         return root_info->indirect_levels;
  97 }
  98
  99 /**@brief Set number of indirect levels of HTree.
 100  * @param root_info Pointer to root info structure of index
 101  * @param lvl Height of HTree (actually only 0 or 1)
 102  */
 103 static inline void ext4_dir_dx_root_info_set_indirect_levels(
 104     struct ext4_directory_dx_root_info *root_info, uint8_t lvl)
 105 {
 106         root_info->indirect_levels = lvl;
 107 }
 108
 109 /**@brief Get maximum number of index node entries.
 110  * @param climit Pointer to counlimit structure
 111  * @return Maximum of entries in node
 112  */
 113 static inline uint16_t
 114 ext4_dir_dx_countlimit_get_limit(struct ext4_directory_dx_countlimit *climit)
 115 {
 116         return to_le16(climit->limit);
 117 }
 118
 119 /**@brief Set maximum number of index node entries.
 120  * @param climit Pointer to counlimit structure
 121  * @param limit Maximum of entries in node
 122  */
 123 static inline void
 124 ext4_dir_dx_countlimit_set_limit(struct ext4_directory_dx_countlimit *climit,
 125                                  uint16_t limit)
 126 {
 127         climit->limit = to_le16(limit);
 128 }
 129
 130 /**@brief Get current number of index node entries.
 131  * @param climit Pointer to counlimit structure
 132  * @return Number of entries in node
 133  */
 134 static inline uint16_t
 135 ext4_dir_dx_countlimit_get_count(struct ext4_directory_dx_countlimit *climit)
 136 {
 137         return to_le16(climit->count);
 138 }
 139
 140 /**@brief Set current number of index node entries.
 141  * @param climit Pointer to counlimit structure
 142  * @param count Number of entries in node
 143  */
 144 static inline void
 145 ext4_dir_dx_countlimit_set_count(struct ext4_directory_dx_countlimit *climit,
 146                                  uint16_t count)
 147 {
 148         climit->count = to_le16(count);
 149 }
 150
 151 /**@brief Get hash value of index entry.
 152  * @param entry Pointer to index entry
 153  * @return Hash value
 154  */
 155 static inline uint32_t
 156 ext4_dir_dx_entry_get_hash(struct ext4_directory_dx_entry *entry)
 157 {
 158         return to_le32(entry->hash);
 159 }
 160
 161 /**@brief Set hash value of index entry.
 162  * @param entry Pointer to index entry
 163  * @param hash  Hash value
 164  */
 165 static inline void
 166 ext4_dir_dx_entry_set_hash(struct ext4_directory_dx_entry *entry, uint32_t hash)
 167 {
 168         entry->hash = to_le32(hash);
 169 }
 170
 171 /**@brief Get block address where child node is located.
 172  * @param entry Pointer to index entry
 173  * @return Block address of child node
 174  */
 175 static inline uint32_t
 176 ext4_dir_dx_entry_get_block(struct ext4_directory_dx_entry *entry)
 177 {
 178         return to_le32(entry->block);
 179 }
 180
 181 /**@brief Set block address where child node is located.
 182  * @param entry Pointer to index entry
 183  * @param block Block address of child node
 184  */
 185 static inline void
 186 ext4_dir_dx_entry_set_block(struct ext4_directory_dx_entry *entry,
 187                             uint32_t block)
 188 {
 189         entry->block = to_le32(block);
 190 }
 191
 192 /**@brief Sort entry item.*/
 193 struct ext4_dx_sort_entry {
 194         uint32_t hash;
 195         uint32_t rec_len;
 196         void *dentry;
 197 };
 198
 199 static int ext4_dir_dx_hash_string(struct ext4_hash_info *hinfo, int len,
 200                                    const char *name)
 201 {
 202         return ext2_htree_hash(name, len, hinfo->seed, hinfo->hash_version,
 203                                &hinfo->hash, &hinfo->minor_hash);
 204 }
 205
 206 static uint32_t
 207 ext4_dir_dx_checksum(struct ext4_inode_ref *inode_ref,
 208                  void *dirent,
 209                  int count_offset, int count, struct ext4_directory_dx_tail *t)
 210 {
 211         uint32_t orig_checksum, checksum = 0;
 212         struct ext4_sblock *sb = &inode_ref->fs->sb;
 213         int size;
 214
 215         /* Compute the checksum only if the filesystem supports it */
 216         if (ext4_sb_has_feature_read_only(sb,
 217                                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
 218                 size = count_offset +
 219                         (count * sizeof(struct ext4_directory_dx_tail));
 220                 orig_checksum = t->checksum;
 221                 t->checksum = 0;
 222                 /* First calculate crc32 checksum against fs uuid */
 223                 checksum = ext4_crc32c(~0, sb->uuid, sizeof(sb->uuid));
 224                 /* Then calculate crc32 checksum against all the dx_entry */
 225                 checksum = ext4_crc32c(checksum, dirent, size);
 226                 /* Finally calculate crc32 checksum for dx_tail */
 227                 checksum = ext4_crc32c(checksum, t,
 228                                 sizeof(struct ext4_directory_dx_tail));
 229                 t->checksum = orig_checksum;
 230         }
 231         return checksum;
 232 }
 233
 234 static struct ext4_directory_dx_countlimit *
 235 ext4_dir_dx_get_countlimit(struct ext4_inode_ref *inode_ref,
 236                         struct ext4_directory_entry_ll *dirent,
 237                         int *offset)
 238 {
 239         struct ext4_directory_entry_ll *dp;
 240         struct ext4_directory_dx_root *root;
 241         struct ext4_sblock *sb = &inode_ref->fs->sb;
 242         int count_offset;
 243
 244         if (ext4_dir_entry_ll_get_entry_length(dirent) ==
 245                         ext4_sb_get_block_size(sb))
 246                 count_offset = 8;
 247         else if (ext4_dir_entry_ll_get_entry_length(dirent) == 12) {
 248                 root = (struct ext4_directory_dx_root *)dirent;
 249                 dp = (struct ext4_directory_entry_ll *)&root->dots[1];
 250                 if (ext4_dir_entry_ll_get_entry_length(dp) !=
 251                     ext4_sb_get_block_size(sb) - 12)
 252                         return NULL;
 253                 if (root->info.reserved_zero ||
 254                     root->info.info_length != sizeof(struct ext4_directory_dx_root_info))
 255                         return NULL;
 256                 count_offset = 32;
 257         } else
 258                 return NULL;
 259
 260         if (offset)
 261                 *offset = count_offset;
 262         return (struct ext4_directory_dx_countlimit *)(((char *)dirent) + count_offset);
 263 }
 264
 265 /*
 266  * BIG FAT NOTES:
 267  *       Currently we do not verify the checksum of HTree node.
 268  */
 269 __unused static int
 270 ext4_dir_dx_checksum_verify(struct ext4_inode_ref *inode_ref,
 271                                 struct ext4_directory_entry_ll *dirent)
 272 {
 273         struct ext4_sblock *sb = &inode_ref->fs->sb;
 274         int count_offset, limit, count;
 275
 276         if (ext4_sb_has_feature_read_only(sb,
 277                                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
 278                 struct ext4_directory_dx_countlimit *countlimit =
 279                         ext4_dir_dx_get_countlimit(inode_ref, dirent, &count_offset);
 280                 if (!countlimit) {
 281                         /* Directory seems corrupted. */
 282                         return 1;
 283                 }
 284                 struct ext4_directory_dx_tail *t;
 285                 limit = ext4_dir_dx_countlimit_get_limit(countlimit);
 286                 count = ext4_dir_dx_countlimit_get_count(countlimit);
 287                 if (count_offset + (limit * sizeof(struct ext4_directory_dx_entry)) >
 288                                 ext4_sb_get_block_size(sb) -
 289                                 sizeof(struct ext4_directory_dx_tail)) {
 290                         /* There is no space to hold the checksum */
 291                         return 1;
 292                 }
 293                 t = (struct ext4_directory_dx_tail *)
 294                         (((struct ext4_directory_dx_entry *)countlimit) + limit);
 295
 296                 if (t->checksum != to_le32(ext4_dir_dx_checksum(inode_ref,
 297                                                                 dirent,
 298                                                                 count_offset,
 299                                                                 count, t)))
 300                         return 0;
 301         }
 302         return 1;
 303 }
 304
 305 static void
 306 ext4_dir_set_dx_checksum(struct ext4_inode_ref *inode_ref,
 307                         struct ext4_directory_entry_ll *dirent)
 308 {
 309         int count_offset, limit, count;
 310         struct ext4_sblock *sb = &inode_ref->fs->sb;
 311
 312         if (ext4_sb_has_feature_read_only(sb,
 313                                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
 314                 struct ext4_directory_dx_countlimit *countlimit =
 315                         ext4_dir_dx_get_countlimit(inode_ref, dirent, &count_offset);
 316                 if (!countlimit) {
 317                         /* Directory seems corrupted. */
 318                         return;
 319                 }
 320                 struct ext4_directory_dx_tail *t;
 321                 limit = ext4_dir_dx_countlimit_get_limit(countlimit);
 322                 count = ext4_dir_dx_countlimit_get_count(countlimit);
 323                 if (count_offset + (limit * sizeof(struct ext4_directory_dx_entry)) >
 324                                 ext4_sb_get_block_size(sb) -
 325                                 sizeof(struct ext4_directory_dx_tail)) {
 326                         /* There is no space to hold the checksum */
 327                         return;
 328                 }
 329                 t = (struct ext4_directory_dx_tail *)
 330                         (((struct ext4_directory_dx_entry *)countlimit) + limit);
 331
 332                 t->checksum =
 333                         to_le32(ext4_dir_dx_checksum(inode_ref, dirent, count_offset, count, t));
 334         }
 335 }
 336
 337 /****************************************************************************/
 338
 339 int ext4_dir_dx_init(struct ext4_inode_ref *dir)
 340 {
 341         /* Load block 0, where will be index root located */
 342         ext4_fsblk_t fblock;
 343         struct ext4_sblock *sb = &dir->fs->sb;
 344         int rc = ext4_fs_get_inode_data_block_index(dir, 0, &fblock, false);
 345         if (rc != EOK)
 346                 return rc;
 347
 348         struct ext4_block block;
 349         rc = ext4_block_get(dir->fs->bdev, &block, fblock);
 350         if (rc != EOK)
 351                 return rc;
 352
 353         /* Initialize pointers to data structures */
 354         struct ext4_directory_dx_root *root = (void *)block.data;
 355         struct ext4_directory_dx_root_info *info = &(root->info);
 356
 357         /* Initialize root info structure */
 358         uint8_t hash_version = ext4_get8(&dir->fs->sb, default_hash_version);
 359
 360         ext4_dir_dx_root_info_set_hash_version(info, hash_version);
 361         ext4_dir_dx_root_info_set_indirect_levels(info, 0);
 362         ext4_dir_dx_root_info_set_info_length(info, 8);
 363
 364         /* Set limit and current number of entries */
 365         struct ext4_directory_dx_countlimit *countlimit =
 366             (struct ext4_directory_dx_countlimit *)&root->entries;
 367
 368         ext4_dir_dx_countlimit_set_count(countlimit, 1);
 369
 370         uint32_t block_size = ext4_sb_get_block_size(&dir->fs->sb);
 371         uint32_t entry_space = block_size -
 372                                2 * sizeof(struct ext4_directory_dx_dot_entry) -
 373                                sizeof(struct ext4_directory_dx_root_info);
 374         uint16_t root_limit =
 375             entry_space / sizeof(struct ext4_directory_dx_entry);
 376         ext4_dir_dx_countlimit_set_limit(countlimit, root_limit);
 377
 378         /* Append new block, where will be new entries inserted in the future */
 379         uint32_t iblock;
 380         rc = ext4_fs_append_inode_block(dir, &fblock, &iblock);
 381         if (rc != EOK) {
 382                 ext4_block_set(dir->fs->bdev, &block);
 383                 return rc;
 384         }
 385
 386         struct ext4_block new_block;
 387
 388         rc = ext4_block_get(dir->fs->bdev, &new_block, fblock);
 389         if (rc != EOK) {
 390                 ext4_block_set(dir->fs->bdev, &block);
 391                 return rc;
 392         }
 393
 394         /* Fill the whole block with empty entry */
 395         struct ext4_directory_entry_ll *block_entry = (void *)new_block.data;
 396
 397         if (ext4_sb_has_feature_read_only(sb,
 398                                           EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
 399                 ext4_dir_entry_ll_set_entry_length(block_entry,
 400                                 sizeof(struct ext4_directory_entry_tail));
 401                 ext4_dir_entry_ll_set_name_length(sb,
 402                                                   block_entry,
 403                                                   0);
 404                 ext4_dir_entry_ll_set_inode_type(sb,
 405                                                  block_entry,
 406                                                  EXT4_DIRENTRY_DIR_CSUM);
 407                 ext4_dir_set_checksum(dir,
 408                                 (struct ext4_directory_entry_ll *)new_block.data);
 409         } else {
 410                 ext4_dir_entry_ll_set_entry_length(block_entry, block_size);
 411         }
 412
 413         ext4_dir_entry_ll_set_inode(block_entry, 0);
 414
 415         new_block.dirty = true;
 416         rc = ext4_block_set(dir->fs->bdev, &new_block);
 417         if (rc != EOK) {
 418                 ext4_block_set(dir->fs->bdev, &block);
 419                 return rc;
 420         }
 421
 422         /* Connect new block to the only entry in index */
 423         struct ext4_directory_dx_entry *entry = root->entries;
 424         ext4_dir_dx_entry_set_block(entry, iblock);
 425
 426         ext4_dir_set_dx_checksum(dir,
 427                         (struct ext4_directory_entry_ll *)block.data);
 428         block.dirty = true;
 429
 430         return ext4_block_set(dir->fs->bdev, &block);
 431 }
 432
 433 /**@brief Initialize hash info structure necessary for index operations.
 434  * @param hinfo      Pointer to hinfo to be initialized
 435  * @param root_block Root block (number 0) of index
 436  * @param sb         Pointer to superblock
 437  * @param name_len   Length of name to be computed hash value from
 438  * @param name       Name to be computed hash value from
 439  * @return Standard error code
 440  */
 441 static int ext4_dir_hinfo_init(struct ext4_hash_info *hinfo,
 442                                struct ext4_block *root_block,
 443                                struct ext4_sblock *sb, size_t name_len,
 444                                const char *name)
 445 {
 446         struct ext4_directory_dx_root *root =
 447             (struct ext4_directory_dx_root *)root_block->data;
 448
 449         if ((root->info.hash_version != EXT2_HTREE_LEGACY) &&
 450             (root->info.hash_version != EXT2_HTREE_HALF_MD4) &&
 451             (root->info.hash_version != EXT2_HTREE_TEA))
 452                 return EXT4_ERR_BAD_DX_DIR;
 453
 454         /* Check unused flags */
 455         if (root->info.unused_flags != 0)
 456                 return EXT4_ERR_BAD_DX_DIR;
 457
 458         /* Check indirect levels */
 459         if (root->info.indirect_levels > 1)
 460                 return EXT4_ERR_BAD_DX_DIR;
 461
 462         /* Check if node limit is correct */
 463         uint32_t block_size = ext4_sb_get_block_size(sb);
 464         uint32_t entry_space = block_size;
 465         entry_space -= 2 * sizeof(struct ext4_directory_dx_dot_entry);
 466         entry_space -= sizeof(struct ext4_directory_dx_root_info);
 467         entry_space = entry_space / sizeof(struct ext4_directory_dx_entry);
 468
 469         uint16_t limit = ext4_dir_dx_countlimit_get_limit(
 470             (struct ext4_directory_dx_countlimit *)&root->entries);
 471         if (limit != entry_space)
 472                 return EXT4_ERR_BAD_DX_DIR;
 473
 474         /* Check hash version and modify if necessary */
 475         hinfo->hash_version =
 476             ext4_dir_dx_root_info_get_hash_version(&root->info);
 477         if ((hinfo->hash_version <= EXT2_HTREE_TEA) &&
 478             (ext4_sb_check_flag(sb, EXT4_SUPERBLOCK_FLAGS_UNSIGNED_HASH))) {
 479                 /* Use unsigned hash */
 480                 hinfo->hash_version += 3;
 481         }
 482
 483         /* Load hash seed from superblock */
 484
 485         hinfo->seed = ext4_get8(sb, hash_seed);
 486
 487         /* Compute hash value of name */
 488         if (name)
 489                 return ext4_dir_dx_hash_string(hinfo, name_len, name);
 490
 491         return EOK;
 492 }
 493
 494 /**@brief Walk through index tree and load leaf with corresponding hash value.
 495  * @param hinfo      Initialized hash info structure
 496  * @param inode_ref  Current i-node
 497  * @param root_block Root block (iblock 0), where is root node located
 498  * @param dx_block   Pointer to leaf node in dx_blocks array
 499  * @param dx_blocks  Array with the whole path from root to leaf
 500  * @return Standard error code
 501  */
 502 static int ext4_dir_dx_get_leaf(struct ext4_hash_info *hinfo,
 503                                 struct ext4_inode_ref *inode_ref,
 504                                 struct ext4_block *root_block,
 505                                 struct ext4_directory_dx_block **dx_block,
 506                                 struct ext4_directory_dx_block *dx_blocks)
 507 {
 508         struct ext4_directory_dx_block *tmp_dx_block = dx_blocks;
 509         struct ext4_directory_dx_root *root =
 510             (struct ext4_directory_dx_root *)root_block->data;
 511         struct ext4_directory_dx_entry *entries =
 512             (struct ext4_directory_dx_entry *)&root->entries;
 513
 514         uint16_t limit = ext4_dir_dx_countlimit_get_limit(
 515             (struct ext4_directory_dx_countlimit *)entries);
 516         uint8_t indirect_level =
 517             ext4_dir_dx_root_info_get_indirect_levels(&root->info);
 518
 519         struct ext4_block *tmp_block = root_block;
 520         struct ext4_directory_dx_entry *p;
 521         struct ext4_directory_dx_entry *q;
 522         struct ext4_directory_dx_entry *m;
 523         struct ext4_directory_dx_entry *at;
 524
 525         /* Walk through the index tree */
 526         while (true) {
 527                 uint16_t count = ext4_dir_dx_countlimit_get_count(
 528                     (struct ext4_directory_dx_countlimit *)entries);
 529                 if ((count == 0) || (count > limit))
 530                         return EXT4_ERR_BAD_DX_DIR;
 531
 532                 /* Do binary search in every node */
 533                 p = entries + 1;
 534                 q = entries + count - 1;
 535
 536                 while (p <= q) {
 537                         m = p + (q - p) / 2;
 538                         if (ext4_dir_dx_entry_get_hash(m) > hinfo->hash)
 539                                 q = m - 1;
 540                         else
 541                                 p = m + 1;
 542                 }
 543
 544                 at = p - 1;
 545
 546                 /* Write results */
 547
 548                 memcpy(&tmp_dx_block->block, tmp_block,
 549                        sizeof(struct ext4_block));
 550                 tmp_dx_block->entries = entries;
 551                 tmp_dx_block->position = at;
 552
 553                 /* Is algorithm in the leaf? */
 554                 if (indirect_level == 0) {
 555                         *dx_block = tmp_dx_block;
 556                         return EOK;
 557                 }
 558
 559                 /* Goto child node */
 560                 uint32_t next_block = ext4_dir_dx_entry_get_block(at);
 561
 562                 indirect_level--;
 563
 564                 ext4_fsblk_t fblock;
 565                 int rc = ext4_fs_get_inode_data_block_index(
 566                     inode_ref, next_block, &fblock, false);
 567                 if (rc != EOK)
 568                         return rc;
 569
 570                 rc = ext4_block_get(inode_ref->fs->bdev, tmp_block, fblock);
 571                 if (rc != EOK)
 572                         return rc;
 573
 574                 entries =
 575                     ((struct ext4_directory_dx_node *)tmp_block->data)->entries;
 576                 limit = ext4_dir_dx_countlimit_get_limit(
 577                     (struct ext4_directory_dx_countlimit *)entries);
 578
 579                 uint16_t entry_space =
 580                     ext4_sb_get_block_size(&inode_ref->fs->sb) -
 581                     sizeof(struct ext4_fake_directory_entry);
 582
 583                 entry_space =
 584                     entry_space / sizeof(struct ext4_directory_dx_entry);
 585
 586                 if (limit != entry_space) {
 587                         ext4_block_set(inode_ref->fs->bdev, tmp_block);
 588                         return EXT4_ERR_BAD_DX_DIR;
 589                 }
 590
 591                 ++tmp_dx_block;
 592         }
 593
 594         /* Unreachable */
 595         return EOK;
 596 }
 597
 598 /**@brief Check if the the next block would be checked during entry search.
 599  * @param inode_ref Directory i-node
 600  * @param hash      Hash value to check
 601  * @param dx_block  Current block
 602  * @param dx_blocks Array with path from root to leaf node
 603  * @return Standard Error code
 604  */
 605 static int ext4_dir_dx_next_block(struct ext4_inode_ref *inode_ref,
 606                                   uint32_t hash,
 607                                   struct ext4_directory_dx_block *dx_block,
 608                                   struct ext4_directory_dx_block *dx_blocks)
 609 {
 610         uint32_t num_handles = 0;
 611         struct ext4_directory_dx_block *p = dx_block;
 612
 613         /* Try to find data block with next bunch of entries */
 614         while (true) {
 615                 p->position++;
 616                 uint16_t count = ext4_dir_dx_countlimit_get_count(
 617                     (struct ext4_directory_dx_countlimit *)p->entries);
 618
 619                 if (p->position < p->entries + count)
 620                         break;
 621
 622                 if (p == dx_blocks)
 623                         return EOK;
 624
 625                 num_handles++;
 626                 p--;
 627         }
 628
 629         /* Check hash collision (if not occurred - no next block cannot be
 630          * used)*/
 631         uint32_t current_hash = ext4_dir_dx_entry_get_hash(p->position);
 632         if ((hash & 1) == 0) {
 633                 if ((current_hash & ~1) != hash)
 634                         return 0;
 635         }
 636
 637         /* Fill new path */
 638         while (num_handles--) {
 639                 uint32_t block_idx = ext4_dir_dx_entry_get_block(p->position);
 640                 ext4_fsblk_t block_addr;
 641
 642                 int rc = ext4_fs_get_inode_data_block_index(
 643                     inode_ref, block_idx, &block_addr, false);
 644                 if (rc != EOK)
 645                         return rc;
 646
 647                 struct ext4_block block;
 648                 rc = ext4_block_get(inode_ref->fs->bdev, &block, block_addr);
 649                 if (rc != EOK)
 650                         return rc;
 651
 652                 p++;
 653
 654                 /* Don't forget to put old block (prevent memory leak) */
 655                 rc = ext4_block_set(inode_ref->fs->bdev, &p->block);
 656                 if (rc != EOK)
 657                         return rc;
 658
 659                 memcpy(&p->block, &block, sizeof(block));
 660                 p->entries =
 661                     ((struct ext4_directory_dx_node *)block.data)->entries;
 662                 p->position = p->entries;
 663         }
 664
 665         return ENOENT;
 666 }
 667
 668 int ext4_dir_dx_find_entry(struct ext4_directory_search_result *result,
 669                            struct ext4_inode_ref *inode_ref, size_t name_len,
 670                            const char *name)
 671 {
 672         /* Load direct block 0 (index root) */
 673         ext4_fsblk_t root_block_addr;
 674         int rc2;
 675         int rc =
 676             ext4_fs_get_inode_data_block_index(inode_ref,
 677                             0, &root_block_addr, false);
 678         if (rc != EOK)
 679                 return rc;
 680
 681         struct ext4_fs *fs = inode_ref->fs;
 682
 683         struct ext4_block root_block;
 684         rc = ext4_block_get(fs->bdev, &root_block, root_block_addr);
 685         if (rc != EOK)
 686                 return rc;
 687
 688         /* Initialize hash info (compute hash value) */
 689         struct ext4_hash_info hinfo;
 690         rc = ext4_dir_hinfo_init(&hinfo, &root_block, &fs->sb, name_len, name);
 691         if (rc != EOK) {
 692                 ext4_block_set(fs->bdev, &root_block);
 693                 return EXT4_ERR_BAD_DX_DIR;
 694         }
 695
 696         /*
 697          * Hardcoded number 2 means maximum height of index tree,
 698          * specified in the Linux driver.
 699          */
 700         struct ext4_directory_dx_block dx_blocks[2];
 701         struct ext4_directory_dx_block *dx_block;
 702         struct ext4_directory_dx_block *tmp;
 703
 704         rc = ext4_dir_dx_get_leaf(&hinfo, inode_ref, &root_block, &dx_block,
 705                                   dx_blocks);
 706         if (rc != EOK) {
 707                 ext4_block_set(fs->bdev, &root_block);
 708                 return EXT4_ERR_BAD_DX_DIR;
 709         }
 710
 711         do {
 712                 /* Load leaf block */
 713                 uint32_t leaf_block_idx =
 714                     ext4_dir_dx_entry_get_block(dx_block->position);
 715                 ext4_fsblk_t leaf_block_addr;
 716
 717                 rc = ext4_fs_get_inode_data_block_index(
 718                     inode_ref, leaf_block_idx, &leaf_block_addr,
 719                     false);
 720                 if (rc != EOK)
 721                         goto cleanup;
 722
 723                 struct ext4_block leaf_block;
 724                 rc = ext4_block_get(fs->bdev, &leaf_block, leaf_block_addr);
 725                 if (rc != EOK)
 726                         goto cleanup;
 727
 728                 /* Linear search inside block */
 729                 struct ext4_directory_entry_ll *res_dentry;
 730                 rc = ext4_dir_find_in_block(&leaf_block, &fs->sb, name_len,
 731                                             name, &res_dentry);
 732
 733                 /* Found => return it */
 734                 if (rc == EOK) {
 735                         result->block = leaf_block;
 736                         result->dentry = res_dentry;
 737                         goto cleanup;
 738                 }
 739
 740                 /* Not found, leave untouched */
 741                 rc2 = ext4_block_set(fs->bdev, &leaf_block);
 742                 if (rc2 != EOK)
 743                         goto cleanup;
 744
 745                 if (rc != ENOENT)
 746                         goto cleanup;
 747
 748                 /* check if the next block could be checked */
 749                 rc = ext4_dir_dx_next_block(inode_ref, hinfo.hash, dx_block,
 750                                             &dx_blocks[0]);
 751                 if (rc < 0)
 752                         goto cleanup;
 753         } while (rc == ENOENT);
 754
 755         /* Entry not found */
 756         rc = ENOENT;
 757
 758 cleanup:
 759         /* The whole path must be released (preventing memory leak) */
 760         tmp = dx_blocks;
 761
 762         while (tmp <= dx_block) {
 763                 rc2 = ext4_block_set(fs->bdev, &tmp->block);
 764                 if (rc == EOK && rc2 != EOK)
 765                         rc = rc2;
 766                 ++tmp;
 767         }
 768
 769         return rc;
 770 }
 771
 772 #if CONFIG_DIR_INDEX_COMB_SORT
 773 #define SWAP_ENTRY(se1, se2)                                                   \
 774         do {                                                                   \
 775                 struct ext4_dx_sort_entry tmp = se1;                           \
 776                 se1 = se2;                                                     \
 777                 se2 = tmp;                                                     \
 778         \
 779 } while (0)
 780
 781 static void comb_sort(struct ext4_dx_sort_entry *se, uint32_t count)
 782 {
 783         struct ext4_dx_sort_entry *p, *q, *top = se + count - 1;
 784         bool more;
 785         /* Combsort */
 786         while (count > 2) {
 787                 count = (count * 10) / 13;
 788                 if (count - 9 < 2)
 789                         count = 11;
 790                 for (p = top, q = p - count; q >= se; p--, q--)
 791                         if (p->hash < q->hash)
 792                                 SWAP_ENTRY(*p, *q);
 793         }
 794         /* Bubblesort */
 795         do {
 796                 more = 0;
 797                 q = top;
 798                 while (q-- > se) {
 799                         if (q[1].hash >= q[0].hash)
 800                                 continue;
 801                         SWAP_ENTRY(*(q + 1), *q);
 802                         more = 1;
 803                 }
 804         } while (more);
 805 }
 806 #else
 807
 808 /**@brief  Compare function used to pass in quicksort implementation.
 809  *         It can compare two entries by hash value.
 810  * @param arg1  First entry
 811  * @param arg2  Second entry
 812  * @param dummy Unused parameter, can be NULL
 813  *
 814  * @return Classic compare result
 815  *         (0: equal, -1: arg1 < arg2, 1: arg1 > arg2)
 816  */
 817 static int ext4_dir_dx_entry_comparator(const void *arg1, const void *arg2)
 818 {
 819         struct ext4_dx_sort_entry *entry1 = (void *)arg1;
 820         struct ext4_dx_sort_entry *entry2 = (void *)arg2;
 821
 822         if (entry1->hash == entry2->hash)
 823                 return 0;
 824
 825         if (entry1->hash < entry2->hash)
 826                 return -1;
 827         else
 828                 return 1;
 829 }
 830 #endif
 831
 832 /**@brief  Insert new index entry to block.
 833  *         Note that space for new entry must be checked by caller.
 834  * @param inode_ref   Directory i-node
 835  * @param index_block Block where to insert new entry
 836  * @param hash        Hash value covered by child node
 837  * @param iblock      Logical number of child block
 838  *
 839  */
 840 static void
 841 ext4_dir_dx_insert_entry(struct ext4_inode_ref *inode_ref,
 842                          struct ext4_directory_dx_block *index_block,
 843                          uint32_t hash, uint32_t iblock)
 844 {
 845         struct ext4_directory_dx_entry *old_index_entry = index_block->position;
 846         struct ext4_directory_dx_entry *new_index_entry = old_index_entry + 1;
 847
 848         struct ext4_directory_dx_countlimit *countlimit =
 849             (struct ext4_directory_dx_countlimit *)index_block->entries;
 850         uint32_t count = ext4_dir_dx_countlimit_get_count(countlimit);
 851
 852         struct ext4_directory_dx_entry *start_index = index_block->entries;
 853         size_t bytes =
 854             (uint8_t *)(start_index + count) - (uint8_t *)(new_index_entry);
 855
 856         memmove(new_index_entry + 1, new_index_entry, bytes);
 857
 858         ext4_dir_dx_entry_set_block(new_index_entry, iblock);
 859         ext4_dir_dx_entry_set_hash(new_index_entry, hash);
 860
 861         ext4_dir_dx_countlimit_set_count(countlimit, count + 1);
 862
 863         ext4_dir_set_dx_checksum(inode_ref,
 864                         (struct ext4_directory_entry_ll *)index_block->block.data);
 865         index_block->block.dirty = true;
 866 }
 867
 868 /**@brief Split directory entries to two parts preventing node overflow.
 869  * @param inode_ref      Directory i-node
 870  * @param hinfo          Hash info
 871  * @param old_data_block Block with data to be split
 872  * @param index_block    Block where index entries are located
 873  * @param new_data_block Output value for newly allocated data block
 874  */
 875 static int ext4_dir_dx_split_data(struct ext4_inode_ref *inode_ref,
 876                                   struct ext4_hash_info *hinfo,
 877                                   struct ext4_block *old_data_block,
 878                                   struct ext4_directory_dx_block *index_block,
 879                                   struct ext4_block *new_data_block)
 880 {
 881         int rc = EOK;
 882
 883         /* Allocate buffer for directory entries */
 884         uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
 885
 886         uint8_t *entry_buffer = malloc(block_size);
 887         if (entry_buffer == NULL)
 888                 return ENOMEM;
 889
 890         /* dot entry has the smallest size available */
 891         uint32_t max_entry_count =
 892             block_size / sizeof(struct ext4_directory_dx_dot_entry);
 893
 894         /* Allocate sort entry */
 895         struct ext4_dx_sort_entry *sort_array =
 896             malloc(max_entry_count * sizeof(struct ext4_dx_sort_entry));
 897
 898         if (sort_array == NULL) {
 899                 free(entry_buffer);
 900                 return ENOMEM;
 901         }
 902
 903         uint32_t idx = 0;
 904         uint32_t real_size = 0;
 905
 906         /* Initialize hinfo */
 907         struct ext4_hash_info tmp_hinfo;
 908         memcpy(&tmp_hinfo, hinfo, sizeof(struct ext4_hash_info));
 909
 910         /* Load all valid entries to the buffer */
 911         struct ext4_directory_entry_ll *dentry = (void *)old_data_block->data;
 912         uint8_t *entry_buffer_ptr = entry_buffer;
 913         while ((void *)dentry < (void *)(old_data_block->data + block_size)) {
 914                 /* Read only valid entries */
 915                 if (ext4_dir_entry_ll_get_inode(dentry) &&
 916                     dentry->name_length) {
 917                         uint8_t len = ext4_dir_entry_ll_get_name_length(
 918                             &inode_ref->fs->sb, dentry);
 919
 920                         rc = ext4_dir_dx_hash_string(&tmp_hinfo, len,
 921                                                      (char *)dentry->name);
 922                         if (rc != EOK) {
 923                                 free(sort_array);
 924                                 free(entry_buffer);
 925                                 return rc;
 926                         }
 927
 928                         uint32_t rec_len = 8 + len;
 929
 930                         if ((rec_len % 4) != 0)
 931                                 rec_len += 4 - (rec_len % 4);
 932
 933                         memcpy(entry_buffer_ptr, dentry, rec_len);
 934
 935                         sort_array[idx].dentry = entry_buffer_ptr;
 936                         sort_array[idx].rec_len = rec_len;
 937                         sort_array[idx].hash = tmp_hinfo.hash;
 938
 939                         entry_buffer_ptr += rec_len;
 940                         real_size += rec_len;
 941                         idx++;
 942                 }
 943
 944                 dentry = (void *)((uint8_t *)dentry +
 945                                   ext4_dir_entry_ll_get_entry_length(dentry));
 946         }
 947
 948 /* Sort all entries */
 949 #if CONFIG_DIR_INDEX_COMB_SORT
 950         comb_sort(sort_array, idx);
 951 #else
 952         qsort(sort_array, idx, sizeof(struct ext4_dx_sort_entry),
 953               ext4_dir_dx_entry_comparator);
 954 #endif
 955         /* Allocate new block for store the second part of entries */
 956         ext4_fsblk_t new_fblock;
 957         uint32_t new_iblock;
 958         rc = ext4_fs_append_inode_block(inode_ref, &new_fblock, &new_iblock);
 959         if (rc != EOK) {
 960                 free(sort_array);
 961                 free(entry_buffer);
 962                 return rc;
 963         }
 964
 965         /* Load new block */
 966         struct ext4_block new_data_block_tmp;
 967         rc = ext4_block_get(inode_ref->fs->bdev, &new_data_block_tmp,
 968                             new_fblock);
 969         if (rc != EOK) {
 970                 free(sort_array);
 971                 free(entry_buffer);
 972                 return rc;
 973         }
 974
 975         /*
 976          * Distribute entries to two blocks (by size)
 977          * - compute the half
 978          */
 979         uint32_t new_hash = 0;
 980         uint32_t current_size = 0;
 981         uint32_t mid = 0;
 982         uint32_t i;
 983         for (i = 0; i < idx; ++i) {
 984                 if ((current_size + sort_array[i].rec_len) > (block_size / 2)) {
 985                         new_hash = sort_array[i].hash;
 986                         mid = i;
 987                         break;
 988                 }
 989
 990                 current_size += sort_array[i].rec_len;
 991         }
 992
 993         /* Check hash collision */
 994         uint32_t continued = 0;
 995         if (new_hash == sort_array[mid - 1].hash)
 996                 continued = 1;
 997
 998         uint32_t offset = 0;
 999         void *ptr;
1000
1001         /* First part - to the old block */
1002         for (i = 0; i < mid; ++i) {
1003                 ptr = old_data_block->data + offset;
1004                 memcpy(ptr, sort_array[i].dentry, sort_array[i].rec_len);
1005
1006                 struct ext4_directory_entry_ll *tmp = ptr;
1007                 if (i < (mid - 1))
1008                         ext4_dir_entry_ll_set_entry_length(
1009                             tmp, sort_array[i].rec_len);
1010                 else
1011                         ext4_dir_entry_ll_set_entry_length(tmp,
1012                                                            block_size - offset);
1013
1014                 offset += sort_array[i].rec_len;
1015         }
1016
1017         /* Second part - to the new block */
1018         offset = 0;
1019         for (i = mid; i < idx; ++i) {
1020                 ptr = new_data_block_tmp.data + offset;
1021                 memcpy(ptr, sort_array[i].dentry, sort_array[i].rec_len);
1022
1023                 struct ext4_directory_entry_ll *tmp = ptr;
1024                 if (i < (idx - 1))
1025                         ext4_dir_entry_ll_set_entry_length(
1026                             tmp, sort_array[i].rec_len);
1027                 else
1028                         ext4_dir_entry_ll_set_entry_length(tmp,
1029                                                            block_size - offset);
1030
1031                 offset += sort_array[i].rec_len;
1032         }
1033
1034         /* Do some steps to finish operation */
1035         ext4_dir_set_dx_checksum(inode_ref,
1036                         (struct ext4_directory_entry_ll *)old_data_block->data);
1037         ext4_dir_set_dx_checksum(inode_ref,
1038                         (struct ext4_directory_entry_ll *)new_data_block_tmp.data);
1039         old_data_block->dirty = true;
1040         new_data_block_tmp.dirty = true;
1041
1042         free(sort_array);
1043         free(entry_buffer);
1044
1045         ext4_dir_dx_insert_entry(inode_ref,
1046                         index_block,
1047                         new_hash + continued, new_iblock);
1048
1049         *new_data_block = new_data_block_tmp;
1050
1051         return EOK;
1052 }
1053
1054 /**@brief  Split index node and maybe some parent nodes in the tree hierarchy.
1055  * @param inode_ref Directory i-node
1056  * @param dx_blocks Array with path from root to leaf node
1057  * @param dx_block  Leaf block to be split if needed
1058  * @return Error code
1059  */
1060 static int
1061 ext4_dir_dx_split_index(struct ext4_inode_ref *inode_ref,
1062                         struct ext4_directory_dx_block *dx_blocks,
1063                         struct ext4_directory_dx_block *dx_block,
1064                         struct ext4_directory_dx_block **new_dx_block)
1065 {
1066         struct ext4_directory_dx_entry *entries;
1067
1068         if (dx_block == dx_blocks)
1069                 entries =
1070                     ((struct ext4_directory_dx_root *)dx_block->block.data)
1071                         ->entries;
1072         else
1073                 entries =
1074                     ((struct ext4_directory_dx_node *)dx_block->block.data)
1075                         ->entries;
1076
1077         struct ext4_directory_dx_countlimit *countlimit =
1078             (struct ext4_directory_dx_countlimit *)entries;
1079
1080         uint16_t leaf_limit = ext4_dir_dx_countlimit_get_limit(countlimit);
1081         uint16_t leaf_count = ext4_dir_dx_countlimit_get_count(countlimit);
1082
1083         /* Check if is necessary to split index block */
1084         if (leaf_limit == leaf_count) {
1085                 size_t levels = dx_block - dx_blocks;
1086
1087                 struct ext4_directory_dx_entry *root_entries =
1088                     ((struct ext4_directory_dx_root *)dx_blocks[0].block.data)
1089                         ->entries;
1090
1091                 struct ext4_directory_dx_countlimit *root_countlimit =
1092                     (struct ext4_directory_dx_countlimit *)root_entries;
1093                 uint16_t root_limit =
1094                     ext4_dir_dx_countlimit_get_limit(root_countlimit);
1095                 uint16_t root_count =
1096                     ext4_dir_dx_countlimit_get_count(root_countlimit);
1097
1098                 /* Linux limitation */
1099                 if ((levels > 0) && (root_limit == root_count))
1100                         return ENOSPC;
1101
1102                 /* Add new block to directory */
1103                 ext4_fsblk_t new_fblock;
1104                 uint32_t new_iblock;
1105                 int rc = ext4_fs_append_inode_block(inode_ref, &new_fblock,
1106                                                     &new_iblock);
1107                 if (rc != EOK)
1108                         return rc;
1109
1110                 /* load new block */
1111                 struct ext4_block new_block;
1112                 rc =
1113                     ext4_block_get(inode_ref->fs->bdev, &new_block, new_fblock);
1114                 if (rc != EOK)
1115                         return rc;
1116
1117                 struct ext4_directory_dx_node *new_node =
1118                     (void *)new_block.data;
1119                 struct ext4_directory_dx_entry *new_entries = new_node->entries;
1120
1121                 memset(&new_node->fake, 0,
1122                        sizeof(struct ext4_fake_directory_entry));
1123
1124                 uint32_t block_size =
1125                     ext4_sb_get_block_size(&inode_ref->fs->sb);
1126
1127                 new_node->fake.entry_length = block_size;
1128
1129                 /* Split leaf node */
1130                 if (levels > 0) {
1131                         uint32_t count_left = leaf_count / 2;
1132                         uint32_t count_right = leaf_count - count_left;
1133                         uint32_t hash_right =
1134                             ext4_dir_dx_entry_get_hash(entries + count_left);
1135
1136                         /* Copy data to new node */
1137                         memcpy((void *)new_entries,
1138                                (void *)(entries + count_left),
1139                                count_right *
1140                                    sizeof(struct ext4_directory_dx_entry));
1141
1142                         /* Initialize new node */
1143                         struct ext4_directory_dx_countlimit *left_countlimit =
1144                             (struct ext4_directory_dx_countlimit *)entries;
1145                         struct ext4_directory_dx_countlimit *right_countlimit =
1146                             (struct ext4_directory_dx_countlimit *)new_entries;
1147
1148                         ext4_dir_dx_countlimit_set_count(left_countlimit,
1149                                                          count_left);
1150                         ext4_dir_dx_countlimit_set_count(right_countlimit,
1151                                                          count_right);
1152
1153                         uint32_t entry_space =
1154                             block_size -
1155                             sizeof(struct ext4_fake_directory_entry);
1156                         uint32_t node_limit =
1157                             entry_space /
1158                             sizeof(struct ext4_directory_dx_entry);
1159                         ext4_dir_dx_countlimit_set_limit(right_countlimit,
1160                                                          node_limit);
1161
1162                         /* Which index block is target for new entry */
1163                         uint32_t position_index =
1164                             (dx_block->position - dx_block->entries);
1165                         if (position_index >= count_left) {
1166                                 ext4_dir_set_dx_checksum(
1167                                                 inode_ref,
1168                                                 (struct ext4_directory_entry_ll *)
1169                                                 dx_block->block.data);
1170                                 dx_block->block.dirty = true;
1171
1172                                 struct ext4_block block_tmp = dx_block->block;
1173
1174                                 dx_block->block = new_block;
1175
1176                                 dx_block->position =
1177                                     new_entries + position_index - count_left;
1178                                 dx_block->entries = new_entries;
1179
1180                                 new_block = block_tmp;
1181                         }
1182
1183                         /* Finally insert new entry */
1184                         ext4_dir_dx_insert_entry(inode_ref,
1185                                                  dx_blocks, hash_right,
1186                                                  new_iblock);
1187                         ext4_dir_set_dx_checksum(inode_ref,
1188                                                 (struct ext4_directory_entry_ll *)
1189                                                         dx_blocks[0].block.data);
1190                         ext4_dir_set_dx_checksum(inode_ref,
1191                                                 (struct ext4_directory_entry_ll *)
1192                                                         dx_blocks[1].block.data);
1193                         dx_blocks[0].block.dirty = true;
1194                         dx_blocks[1].block.dirty = true;
1195
1196                         ext4_dir_set_dx_checksum(inode_ref,
1197                                                 (struct ext4_directory_entry_ll *)
1198                                                         new_block.data);
1199                         new_block.dirty = true;
1200                         return ext4_block_set(inode_ref->fs->bdev, &new_block);
1201                 } else {
1202                         /* Create second level index */
1203
1204                         /* Copy data from root to child block */
1205                         memcpy((void *)new_entries, (void *)entries,
1206                                leaf_count *
1207                                    sizeof(struct ext4_directory_dx_entry));
1208
1209                         struct ext4_directory_dx_countlimit *new_countlimit =
1210                             (struct ext4_directory_dx_countlimit *)new_entries;
1211
1212                         uint32_t entry_space =
1213                             block_size -
1214                             sizeof(struct ext4_fake_directory_entry);
1215                         uint32_t node_limit =
1216                             entry_space /
1217                             sizeof(struct ext4_directory_dx_entry);
1218                         ext4_dir_dx_countlimit_set_limit(new_countlimit,
1219                                                          node_limit);
1220
1221                         /* Set values in root node */
1222                         struct ext4_directory_dx_countlimit
1223                             *new_root_countlimit =
1224                                 (struct ext4_directory_dx_countlimit *)entries;
1225
1226                         ext4_dir_dx_countlimit_set_count(new_root_countlimit,
1227                                                          1);
1228                         ext4_dir_dx_entry_set_block(entries, new_iblock);
1229
1230                         ((struct ext4_directory_dx_root *)dx_blocks[0]
1231                              .block.data)
1232                             ->info.indirect_levels = 1;
1233
1234                         /* Add new entry to the path */
1235                         dx_block = dx_blocks + 1;
1236                         dx_block->position =
1237                             dx_blocks->position - entries + new_entries;
1238                         dx_block->entries = new_entries;
1239                         dx_block->block = new_block;
1240
1241                         *new_dx_block = dx_block;
1242
1243                         ext4_dir_set_dx_checksum(inode_ref,
1244                                                 (struct ext4_directory_entry_ll *)
1245                                                         dx_blocks[0].block.data);
1246                         ext4_dir_set_dx_checksum(inode_ref,
1247                                                 (struct ext4_directory_entry_ll *)
1248                                                         dx_blocks[1].block.data);
1249                         dx_blocks[0].block.dirty = true;
1250                         dx_blocks[1].block.dirty = true;
1251                 }
1252         }
1253
1254         return EOK;
1255 }
1256
1257 int ext4_dir_dx_add_entry(struct ext4_inode_ref *parent,
1258                           struct ext4_inode_ref *child, const char *name)
1259 {
1260         int rc2 = EOK;
1261
1262         /* Get direct block 0 (index root) */
1263         ext4_fsblk_t root_block_addr;
1264         int rc =
1265             ext4_fs_get_inode_data_block_index(parent,
1266                             0, &root_block_addr,
1267                             false);
1268         if (rc != EOK)
1269                 return rc;
1270
1271         struct ext4_fs *fs = parent->fs;
1272         struct ext4_block root_block;
1273
1274         rc = ext4_block_get(fs->bdev, &root_block, root_block_addr);
1275         if (rc != EOK)
1276                 return rc;
1277
1278         /* Initialize hinfo structure (mainly compute hash) */
1279         uint32_t name_len = strlen(name);
1280         struct ext4_hash_info hinfo;
1281         rc = ext4_dir_hinfo_init(&hinfo, &root_block, &fs->sb, name_len, name);
1282         if (rc != EOK) {
1283                 ext4_block_set(fs->bdev, &root_block);
1284                 return EXT4_ERR_BAD_DX_DIR;
1285         }
1286
1287         /*
1288          * Hardcoded number 2 means maximum height of index
1289          * tree defined in Linux.
1290          */
1291         struct ext4_directory_dx_block dx_blocks[2];
1292         struct ext4_directory_dx_block *dx_block;
1293         struct ext4_directory_dx_block *dx_it;
1294
1295         rc = ext4_dir_dx_get_leaf(&hinfo, parent, &root_block, &dx_block,
1296                                   dx_blocks);
1297         if (rc != EOK) {
1298                 rc = EXT4_ERR_BAD_DX_DIR;
1299                 goto release_index;
1300         }
1301
1302         /* Try to insert to existing data block */
1303         uint32_t leaf_block_idx =
1304             ext4_dir_dx_entry_get_block(dx_block->position);
1305         ext4_fsblk_t leaf_block_addr;
1306         rc = ext4_fs_get_inode_data_block_index(parent, leaf_block_idx,
1307                                                 &leaf_block_addr,
1308                                                 false);
1309         if (rc != EOK)
1310                 goto release_index;
1311
1312         /*
1313          * Check if there is needed to split index node
1314          * (and recursively also parent nodes)
1315          */
1316         rc = ext4_dir_dx_split_index(parent, dx_blocks, dx_block, &dx_block);
1317         if (rc != EOK)
1318                 goto release_target_index;
1319
1320         struct ext4_block target_block;
1321         rc = ext4_block_get(fs->bdev, &target_block, leaf_block_addr);
1322         if (rc != EOK)
1323                 goto release_index;
1324
1325         /* Check if insert operation passed */
1326         rc = ext4_dir_try_insert_entry(&fs->sb, parent, &target_block, child, name,
1327                                        name_len);
1328         if (rc == EOK)
1329                 goto release_target_index;
1330
1331         /* Split entries to two blocks (includes sorting by hash value) */
1332         struct ext4_block new_block;
1333         rc = ext4_dir_dx_split_data(parent, &hinfo, &target_block, dx_block,
1334                                     &new_block);
1335         if (rc != EOK) {
1336                 rc2 = rc;
1337                 goto release_target_index;
1338         }
1339
1340         /* Where to save new entry */
1341         uint32_t new_block_hash =
1342             ext4_dir_dx_entry_get_hash(dx_block->position + 1);
1343         if (hinfo.hash >= new_block_hash)
1344                 rc = ext4_dir_try_insert_entry(&fs->sb, parent, &new_block, child, name,
1345                                                name_len);
1346         else
1347                 rc = ext4_dir_try_insert_entry(&fs->sb, parent, &target_block, child,
1348                                                name, name_len);
1349
1350         /* Cleanup */
1351         rc = ext4_block_set(fs->bdev, &new_block);
1352         if (rc != EOK)
1353                 return rc;
1354
1355 /* Cleanup operations */
1356
1357 release_target_index:
1358         rc2 = rc;
1359
1360         rc = ext4_block_set(fs->bdev, &target_block);
1361         if (rc != EOK)
1362                 return rc;
1363
1364 release_index:
1365         if (rc != EOK)
1366                 rc2 = rc;
1367
1368         dx_it = dx_blocks;
1369
1370         while (dx_it <= dx_block) {
1371                 rc = ext4_block_set(fs->bdev, &dx_it->block);
1372                 if (rc != EOK)
1373                         return rc;
1374
1375                 dx_it++;
1376         }
1377
1378         return rc2;
1379 }
1380
1381 int ext4_dir_dx_reset_parent_inode(struct ext4_inode_ref *dir,
1382                                    uint32_t parent_inode)
1383 {
1384         /* Load block 0, where will be index root located */
1385         ext4_fsblk_t fblock;
1386         int rc = ext4_fs_get_inode_data_block_index(dir, 0, &fblock, false);
1387         if (rc != EOK)
1388                 return rc;
1389
1390         struct ext4_block block;
1391         rc = ext4_block_get(dir->fs->bdev, &block, fblock);
1392         if (rc != EOK)
1393                 return rc;
1394
1395         /* Initialize pointers to data structures */
1396         struct ext4_directory_dx_root *root = (void *)block.data;
1397
1398         /* Fill the inode field with a new parent ino. */
1399         ext4_dx_dot_entry_set_inode(&root->dots[1], parent_inode);
1400
1401         ext4_dir_set_dx_checksum(dir,
1402                                 (struct ext4_directory_entry_ll *)
1403                                         block.data);
1404         block.dirty = true;
1405
1406         return ext4_block_set(dir->fs->bdev, &block);
1407 }
1408
1409 /**
1410  * @}
1411  */