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
  55 ext4_dir_dx_rinfo_get_hash_version(struct ext4_dir_idx_rinfo *ri)
  56 {
  57         return ri->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
  65 ext4_dir_dx_rinfo_set_hash_version(struct ext4_dir_idx_rinfo *ri, uint8_t v)
  66 {
  67         ri->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
  75 ext4_dir_dx_rinfo_get_info_length(struct ext4_dir_idx_rinfo *ri)
  76 {
  77         return ri->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
  85 ext4_dir_dx_root_info_set_info_length(struct ext4_dir_idx_rinfo *ri,
  86                                       uint8_t len)
  87 {
  88         ri->info_length = len;
  89 }
  90
  91 /**@brief Get number of indirect levels of HTree.
  92  * @param root_info Pointer to root info structure of index
  93  * @return Height of HTree (actually only 0 or 1)
  94  */
  95 static inline uint8_t
  96 ext4_dir_dx_rinfo_get_indirect_levels(struct ext4_dir_idx_rinfo *ri)
  97 {
  98         return ri->indirect_levels;
  99 }
 100
 101 /**@brief Set number of indirect levels of HTree.
 102  * @param root_info Pointer to root info structure of index
 103  * @param lvl Height of HTree (actually only 0 or 1)
 104  */
 105 static inline void
 106 ext4_dir_dx_rinfo_set_indirect_levels(struct ext4_dir_idx_rinfo *ri, uint8_t l)
 107 {
 108         ri->indirect_levels = l;
 109 }
 110
 111 /**@brief Get maximum number of index node entries.
 112  * @param climit Pointer to counlimit structure
 113  * @return Maximum of entries in node
 114  */
 115 static inline uint16_t
 116 ext4_dir_dx_climit_get_limit(struct ext4_dir_idx_climit *climit)
 117 {
 118         return to_le16(climit->limit);
 119 }
 120
 121 /**@brief Set maximum number of index node entries.
 122  * @param climit Pointer to counlimit structure
 123  * @param limit Maximum of entries in node
 124  */
 125 static inline void
 126 ext4_dir_dx_climit_set_limit(struct ext4_dir_idx_climit *climit, 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_climit_get_count(struct ext4_dir_idx_climit *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_climit_set_count(struct ext4_dir_idx_climit *climit, 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_dir_idx_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_dir_idx_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_dir_idx_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_dir_idx_entry *entry, uint32_t block)
 187 {
 188         entry->block = to_le32(block);
 189 }
 190
 191 /**@brief Sort entry item.*/
 192 struct ext4_dx_sort_entry {
 193         uint32_t hash;
 194         uint32_t rec_len;
 195         void *dentry;
 196 };
 197
 198 static int ext4_dir_dx_hash_string(struct ext4_hash_info *hinfo, int len,
 199                                    const char *name)
 200 {
 201         return ext2_htree_hash(name, len, hinfo->seed, hinfo->hash_version,
 202                                &hinfo->hash, &hinfo->minor_hash);
 203 }
 204
 205 #if CONFIG_META_CSUM_ENABLE
 206 static uint32_t ext4_dir_dx_checksum(struct ext4_inode_ref *inode_ref, void *de,
 207                                      int count_offset, int count,
 208                                      struct ext4_dir_idx_tail *t)
 209 {
 210         uint32_t orig_cum, csum = 0;
 211         struct ext4_sblock *sb = &inode_ref->fs->sb;
 212         int sz;
 213
 214         /* Compute the checksum only if the filesystem supports it */
 215         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
 216                 uint32_t ino_index = to_le32(inode_ref->index);
 217                 uint32_t ino_gen;
 218                 ino_gen = to_le32(ext4_inode_get_generation(inode_ref->inode));
 219
 220                 sz = count_offset + (count * sizeof(struct ext4_dir_idx_tail));
 221                 orig_cum = t->checksum;
 222                 t->checksum = 0;
 223                 /* First calculate crc32 checksum against fs uuid */
 224                 csum = ext4_crc32c(EXT4_CRC32_INIT, sb->uuid, sizeof(sb->uuid));
 225                 /* Then calculate crc32 checksum against inode number
 226                  * and inode generation */
 227                 csum = ext4_crc32c(csum, &ino_index, sizeof(ino_index));
 228                 csum = ext4_crc32c(csum, &ino_gen, sizeof(ino_gen));
 229                 /* After that calculate crc32 checksum against all the dx_entry */
 230                 csum = ext4_crc32c(csum, de, sz);
 231                 /* Finally calculate crc32 checksum for dx_tail */
 232                 csum = ext4_crc32c(csum, t, sizeof(struct ext4_dir_idx_tail));
 233                 t->checksum = orig_cum;
 234         }
 235         return csum;
 236 }
 237
 238 static struct ext4_dir_idx_climit *
 239 ext4_dir_dx_get_climit(struct ext4_inode_ref *inode_ref,
 240                            struct ext4_dir_en *dirent, int *offset)
 241 {
 242         struct ext4_dir_en *dp;
 243         struct ext4_dir_idx_root *root;
 244         struct ext4_sblock *sb = &inode_ref->fs->sb;
 245         uint32_t block_size = ext4_sb_get_block_size(sb);
 246         uint16_t entry_len = ext4_dir_en_get_entry_len(dirent);
 247         int count_offset;
 248
 249
 250         if (entry_len == 12) {
 251                 root = (struct ext4_dir_idx_root *)dirent;
 252                 dp = (struct ext4_dir_en *)&root->dots[1];
 253                 if (ext4_dir_en_get_entry_len(dp) != (block_size - 12))
 254                         return NULL;
 255                 if (root->info.reserved_zero)
 256                         return NULL;
 257                 if (root->info.info_length != sizeof(struct ext4_dir_idx_rinfo))
 258                         return NULL;
 259                 count_offset = 32;
 260         } else if (entry_len == block_size) {
 261                 count_offset = 8;
 262         } else {
 263                 return NULL;
 264         }
 265
 266         if (offset)
 267                 *offset = count_offset;
 268         return (struct ext4_dir_idx_climit *)(((char *)dirent) + count_offset);
 269 }
 270
 271 /*
 272  * BIG FAT NOTES:
 273  *       Currently we do not verify the checksum of HTree node.
 274  */
 275 static bool ext4_dir_dx_csum_verify(struct ext4_inode_ref *inode_ref,
 276                                     struct ext4_dir_en *de)
 277 {
 278         struct ext4_sblock *sb = &inode_ref->fs->sb;
 279         uint32_t block_size = ext4_sb_get_block_size(sb);
 280         int coff, limit, cnt;
 281
 282         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
 283                 struct ext4_dir_idx_climit *climit;
 284                 climit = ext4_dir_dx_get_climit(inode_ref, de, &coff);
 285                 if (!climit) {
 286                         /* Directory seems corrupted. */
 287                         return true;
 288                 }
 289                 struct ext4_dir_idx_tail *t;
 290                 limit = ext4_dir_dx_climit_get_limit(climit);
 291                 cnt = ext4_dir_dx_climit_get_count(climit);
 292                 if (coff + (limit * sizeof(struct ext4_dir_idx_entry)) >
 293                     (block_size - sizeof(struct ext4_dir_idx_tail))) {
 294                         /* There is no space to hold the checksum */
 295                         return true;
 296                 }
 297                 t = (void *)(((struct ext4_dir_idx_entry *)climit) + limit);
 298
 299                 uint32_t c;
 300                 c = to_le32(ext4_dir_dx_checksum(inode_ref, de, coff, cnt, t));
 301                 if (t->checksum != c)
 302                         return false;
 303         }
 304         return true;
 305 }
 306
 307
 308 static void ext4_dir_set_dx_csum(struct ext4_inode_ref *inode_ref,
 309                                  struct ext4_dir_en *dirent)
 310 {
 311         int coff, limit, count;
 312         struct ext4_sblock *sb = &inode_ref->fs->sb;
 313         uint32_t block_size = ext4_sb_get_block_size(sb);
 314
 315         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
 316                 struct ext4_dir_idx_climit *climit;
 317                 climit = ext4_dir_dx_get_climit(inode_ref, dirent, &coff);
 318                 if (!climit) {
 319                         /* Directory seems corrupted. */
 320                         return;
 321                 }
 322                 struct ext4_dir_idx_tail *t;
 323                 limit = ext4_dir_dx_climit_get_limit(climit);
 324                 count = ext4_dir_dx_climit_get_count(climit);
 325                 if (coff + (limit * sizeof(struct ext4_dir_idx_entry)) >
 326                    (block_size - sizeof(struct ext4_dir_idx_tail))) {
 327                         /* There is no space to hold the checksum */
 328                         return;
 329                 }
 330
 331                 t = (void *)(((struct ext4_dir_idx_entry *)climit) + limit);
 332                 t->checksum = to_le32(ext4_dir_dx_checksum(inode_ref, dirent,
 333                                         coff, count, t));
 334         }
 335 }
 336 #else
 337 #define ext4_dir_dx_csum_verify(...) true
 338 #define ext4_dir_set_dx_csum(...)
 339 #endif
 340
 341 /****************************************************************************/
 342
 343 int ext4_dir_dx_init(struct ext4_inode_ref *dir, struct ext4_inode_ref *parent)
 344 {
 345         /* Load block 0, where will be index root located */
 346         ext4_fsblk_t fblock;
 347         uint32_t iblock;
 348         struct ext4_sblock *sb = &dir->fs->sb;
 349         uint32_t block_size = ext4_sb_get_block_size(&dir->fs->sb);
 350
 351         int rc = ext4_fs_append_inode_block(dir, &fblock, &iblock);
 352         if (rc != EOK)
 353                 return rc;
 354
 355         struct ext4_block block;
 356         rc = ext4_block_get_noread(dir->fs->bdev, &block, fblock);
 357         if (rc != EOK)
 358                 return rc;
 359
 360         /* Initialize pointers to data structures */
 361         struct ext4_dir_idx_root *root = (void *)block.data;
 362         struct ext4_dir_idx_rinfo *info = &(root->info);
 363
 364         memset(root, 0, sizeof(struct ext4_dir_idx_root));
 365         struct ext4_dir_en *de;
 366
 367         /* Initialize dot entries */
 368         de = (struct ext4_dir_en *)root->dots;
 369         ext4_dir_write_entry(sb, de, 12, dir, ".", strlen("."));
 370
 371         de = (struct ext4_dir_en *)(root->dots + 1);
 372         uint16_t elen = block_size - 12;
 373         ext4_dir_write_entry(sb, de, elen, parent, "..", strlen(".."));
 374
 375         /* Initialize root info structure */
 376         uint8_t hash_version = ext4_get8(&dir->fs->sb, default_hash_version);
 377
 378         ext4_dir_dx_rinfo_set_hash_version(info, hash_version);
 379         ext4_dir_dx_rinfo_set_indirect_levels(info, 0);
 380         ext4_dir_dx_root_info_set_info_length(info, 8);
 381
 382         /* Set limit and current number of entries */
 383         struct ext4_dir_idx_climit *climit;
 384         climit = (struct ext4_dir_idx_climit *)&root->en;
 385
 386         ext4_dir_dx_climit_set_count(climit, 1);
 387
 388         uint32_t entry_space;
 389         entry_space = block_size - 2 * sizeof(struct ext4_dir_idx_dot_en) -
 390                         sizeof(struct ext4_dir_idx_rinfo);
 391
 392         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 393                 entry_space -= sizeof(struct ext4_dir_idx_tail);
 394
 395         uint16_t root_limit = entry_space / sizeof(struct ext4_dir_idx_entry);
 396         ext4_dir_dx_climit_set_limit(climit, root_limit);
 397
 398         /* Append new block, where will be new entries inserted in the future */
 399         rc = ext4_fs_append_inode_block(dir, &fblock, &iblock);
 400         if (rc != EOK) {
 401                 ext4_block_set(dir->fs->bdev, &block);
 402                 return rc;
 403         }
 404
 405         struct ext4_block new_block;
 406         rc = ext4_block_get_noread(dir->fs->bdev, &new_block, fblock);
 407         if (rc != EOK) {
 408                 ext4_block_set(dir->fs->bdev, &block);
 409                 return rc;
 410         }
 411
 412         /* Fill the whole block with empty entry */
 413         struct ext4_dir_en *be = (void *)new_block.data;
 414
 415         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
 416                 uint16_t len = block_size - sizeof(struct ext4_dir_entry_tail);
 417                 ext4_dir_en_set_entry_len(be, len);
 418                 ext4_dir_en_set_name_len(sb, be, 0);
 419                 ext4_dir_en_set_inode_type(sb, be, EXT4_DE_UNKNOWN);
 420                 ext4_dir_init_entry_tail(EXT4_DIRENT_TAIL(be, block_size));
 421                 ext4_dir_set_csum(dir, be);
 422         } else {
 423                 ext4_dir_en_set_entry_len(be, block_size);
 424         }
 425
 426         ext4_dir_en_set_inode(be, 0);
 427
 428         new_block.dirty = true;
 429         rc = ext4_block_set(dir->fs->bdev, &new_block);
 430         if (rc != EOK) {
 431                 ext4_block_set(dir->fs->bdev, &block);
 432                 return rc;
 433         }
 434
 435         /* Connect new block to the only entry in index */
 436         struct ext4_dir_idx_entry *entry = root->en;
 437         ext4_dir_dx_entry_set_block(entry, iblock);
 438
 439         ext4_dir_set_dx_csum(dir, (struct ext4_dir_en *)block.data);
 440         block.dirty = true;
 441
 442         return ext4_block_set(dir->fs->bdev, &block);
 443 }
 444
 445 /**@brief Initialize hash info structure necessary for index operations.
 446  * @param hinfo      Pointer to hinfo to be initialized
 447  * @param root_block Root block (number 0) of index
 448  * @param sb         Pointer to superblock
 449  * @param name_len   Length of name to be computed hash value from
 450  * @param name       Name to be computed hash value from
 451  * @return Standard error code
 452  */
 453 static int ext4_dir_hinfo_init(struct ext4_hash_info *hinfo,
 454                                struct ext4_block *root_block,
 455                                struct ext4_sblock *sb, size_t name_len,
 456                                const char *name)
 457 {
 458         struct ext4_dir_idx_root *root;
 459
 460         root = (struct ext4_dir_idx_root *)root_block->data;
 461         if ((root->info.hash_version != EXT2_HTREE_LEGACY) &&
 462             (root->info.hash_version != EXT2_HTREE_HALF_MD4) &&
 463             (root->info.hash_version != EXT2_HTREE_TEA))
 464                 return EXT4_ERR_BAD_DX_DIR;
 465
 466         /* Check unused flags */
 467         if (root->info.unused_flags != 0)
 468                 return EXT4_ERR_BAD_DX_DIR;
 469
 470         /* Check indirect levels */
 471         if (root->info.indirect_levels > 1)
 472                 return EXT4_ERR_BAD_DX_DIR;
 473
 474         /* Check if node limit is correct */
 475         uint32_t block_size = ext4_sb_get_block_size(sb);
 476         uint32_t entry_space = block_size;
 477         entry_space -= 2 * sizeof(struct ext4_dir_idx_dot_en);
 478         entry_space -= sizeof(struct ext4_dir_idx_rinfo);
 479         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 480                 entry_space -= sizeof(struct ext4_dir_idx_tail);
 481         entry_space = entry_space / sizeof(struct ext4_dir_idx_entry);
 482
 483         struct ext4_dir_idx_climit *climit = (void *)&root->en;
 484         uint16_t limit = ext4_dir_dx_climit_get_limit(climit);
 485         if (limit != entry_space)
 486                 return EXT4_ERR_BAD_DX_DIR;
 487
 488         /* Check hash version and modify if necessary */
 489         hinfo->hash_version = ext4_dir_dx_rinfo_get_hash_version(&root->info);
 490         if ((hinfo->hash_version <= EXT2_HTREE_TEA) &&
 491             (ext4_sb_check_flag(sb, EXT4_SUPERBLOCK_FLAGS_UNSIGNED_HASH))) {
 492                 /* Use unsigned hash */
 493                 hinfo->hash_version += 3;
 494         }
 495
 496         /* Load hash seed from superblock */
 497         hinfo->seed = ext4_get8(sb, hash_seed);
 498
 499         /* Compute hash value of name */
 500         if (name)
 501                 return ext4_dir_dx_hash_string(hinfo, name_len, name);
 502
 503         return EOK;
 504 }
 505
 506 /**@brief Walk through index tree and load leaf with corresponding hash value.
 507  * @param hinfo      Initialized hash info structure
 508  * @param inode_ref  Current i-node
 509  * @param root_block Root block (iblock 0), where is root node located
 510  * @param dx_block   Pointer to leaf node in dx_blocks array
 511  * @param dx_blocks  Array with the whole path from root to leaf
 512  * @return Standard error code
 513  */
 514 static int ext4_dir_dx_get_leaf(struct ext4_hash_info *hinfo,
 515                                 struct ext4_inode_ref *inode_ref,
 516                                 struct ext4_block *root_block,
 517                                 struct ext4_dir_idx_block **dx_block,
 518                                 struct ext4_dir_idx_block *dx_blocks)
 519 {
 520         struct ext4_dir_idx_root *root;
 521         struct ext4_dir_idx_entry *entries;
 522         struct ext4_dir_idx_entry *p;
 523         struct ext4_dir_idx_entry *q;
 524         struct ext4_dir_idx_entry *m;
 525         struct ext4_dir_idx_entry *at;
 526         ext4_fsblk_t fblock;
 527         uint32_t block_size;
 528         uint16_t limit;
 529         uint16_t entry_space;
 530         uint8_t ind_level;
 531         int r;
 532
 533         struct ext4_dir_idx_block *tmp_dx_blk = dx_blocks;
 534         struct ext4_block *tmp_blk = root_block;
 535         struct ext4_sblock *sb = &inode_ref->fs->sb;
 536
 537         block_size = ext4_sb_get_block_size(sb);
 538         root = (struct ext4_dir_idx_root *)root_block->data;
 539         entries = (struct ext4_dir_idx_entry *)&root->en;
 540         limit = ext4_dir_dx_climit_get_limit((void *)entries);
 541         ind_level = ext4_dir_dx_rinfo_get_indirect_levels(&root->info);
 542
 543         /* Walk through the index tree */
 544         while (true) {
 545                 uint16_t cnt = ext4_dir_dx_climit_get_count((void *)entries);
 546                 if ((cnt == 0) || (cnt > limit))
 547                         return EXT4_ERR_BAD_DX_DIR;
 548
 549                 /* Do binary search in every node */
 550                 p = entries + 1;
 551                 q = entries + cnt - 1;
 552
 553                 while (p <= q) {
 554                         m = p + (q - p) / 2;
 555                         if (ext4_dir_dx_entry_get_hash(m) > hinfo->hash)
 556                                 q = m - 1;
 557                         else
 558                                 p = m + 1;
 559                 }
 560
 561                 at = p - 1;
 562
 563                 /* Write results */
 564                 memcpy(&tmp_dx_blk->b, tmp_blk, sizeof(struct ext4_block));
 565                 tmp_dx_blk->entries = entries;
 566                 tmp_dx_blk->position = at;
 567
 568                 /* Is algorithm in the leaf? */
 569                 if (ind_level == 0) {
 570                         *dx_block = tmp_dx_blk;
 571                         return EOK;
 572                 }
 573
 574                 /* Goto child node */
 575                 uint32_t next_block = ext4_dir_dx_entry_get_block(at);
 576
 577                 ind_level--;
 578
 579                 r = ext4_fs_get_inode_data_block_index(inode_ref, next_block,
 580                                                        &fblock, false);
 581                 if (r != EOK)
 582                         return r;
 583
 584                 r = ext4_block_get(inode_ref->fs->bdev, tmp_blk, fblock);
 585                 if (r != EOK)
 586                         return r;
 587
 588                 entries = ((struct ext4_dir_idx_node *)tmp_blk->data)->entries;
 589                 limit = ext4_dir_dx_climit_get_limit((void *)entries);
 590
 591                 entry_space = block_size - sizeof(struct ext4_fake_dir_entry);
 592                 if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 593                         entry_space -= sizeof(struct ext4_dir_idx_tail);
 594
 595                 entry_space = entry_space / sizeof(struct ext4_dir_idx_entry);
 596
 597                 if (limit != entry_space) {
 598                         ext4_block_set(inode_ref->fs->bdev, tmp_blk);
 599                         return EXT4_ERR_BAD_DX_DIR;
 600                 }
 601
 602                 if (!ext4_dir_dx_csum_verify(inode_ref, (void *)tmp_blk->data)) {
 603                         ext4_dbg(DEBUG_DIR_IDX,
 604                                         DBG_WARN "HTree checksum failed."
 605                                         "Inode: %" PRIu32", "
 606                                         "Block: %" PRIu32"\n",
 607                                         inode_ref->index,
 608                                         next_block);
 609                 }
 610
 611                 ++tmp_dx_blk;
 612         }
 613
 614         /* Unreachable */
 615         return EOK;
 616 }
 617
 618 /**@brief Check if the the next block would be checked during entry search.
 619  * @param inode_ref Directory i-node
 620  * @param hash      Hash value to check
 621  * @param dx_block  Current block
 622  * @param dx_blocks Array with path from root to leaf node
 623  * @return Standard Error code
 624  */
 625 static int ext4_dir_dx_next_block(struct ext4_inode_ref *inode_ref,
 626                                   uint32_t hash,
 627                                   struct ext4_dir_idx_block *dx_block,
 628                                   struct ext4_dir_idx_block *dx_blocks)
 629 {
 630         int r;
 631         uint32_t num_handles = 0;
 632         ext4_fsblk_t block_addr;
 633         struct ext4_dir_idx_block *p = dx_block;
 634
 635         /* Try to find data block with next bunch of entries */
 636         while (true) {
 637                 uint16_t cnt = ext4_dir_dx_climit_get_count((void *)p->entries);
 638
 639                 p->position++;
 640                 if (p->position < p->entries + cnt)
 641                         break;
 642
 643                 if (p == dx_blocks)
 644                         return EOK;
 645
 646                 num_handles++;
 647                 p--;
 648         }
 649
 650         /* Check hash collision (if not occurred - no next block cannot be
 651          * used)*/
 652         uint32_t current_hash = ext4_dir_dx_entry_get_hash(p->position);
 653         if ((hash & 1) == 0) {
 654                 if ((current_hash & ~1) != hash)
 655                         return 0;
 656         }
 657
 658         /* Fill new path */
 659         while (num_handles--) {
 660                 uint32_t block_idx = ext4_dir_dx_entry_get_block(p->position);
 661
 662                 r = ext4_fs_get_inode_data_block_index(inode_ref, block_idx,
 663                                                        &block_addr, false);
 664                 if (r != EOK)
 665                         return r;
 666
 667                 struct ext4_block b;
 668                 r = ext4_block_get(inode_ref->fs->bdev, &b, block_addr);
 669                 if (r != EOK)
 670                         return r;
 671
 672                 if (!ext4_dir_dx_csum_verify(inode_ref, (void *)b.data)) {
 673                         ext4_dbg(DEBUG_DIR_IDX,
 674                                         DBG_WARN "HTree checksum failed."
 675                                         "Inode: %" PRIu32", "
 676                                         "Block: %" PRIu32"\n",
 677                                         inode_ref->index,
 678                                         block_idx);
 679                 }
 680
 681                 p++;
 682
 683                 /* Don't forget to put old block (prevent memory leak) */
 684                 r = ext4_block_set(inode_ref->fs->bdev, &p->b);
 685                 if (r != EOK)
 686                         return r;
 687
 688                 memcpy(&p->b, &b, sizeof(b));
 689                 p->entries = ((struct ext4_dir_idx_node *)b.data)->entries;
 690                 p->position = p->entries;
 691         }
 692
 693         return ENOENT;
 694 }
 695
 696 int ext4_dir_dx_find_entry(struct ext4_dir_search_result *result,
 697                            struct ext4_inode_ref *inode_ref, size_t name_len,
 698                            const char *name)
 699 {
 700         /* Load direct block 0 (index root) */
 701         ext4_fsblk_t root_block_addr;
 702         int rc2;
 703         int rc;
 704         rc = ext4_fs_get_inode_data_block_index(inode_ref,  0, &root_block_addr,
 705                                                false);
 706         if (rc != EOK)
 707                 return rc;
 708
 709         struct ext4_fs *fs = inode_ref->fs;
 710
 711         struct ext4_block root_block;
 712         rc = ext4_block_get(fs->bdev, &root_block, root_block_addr);
 713         if (rc != EOK)
 714                 return rc;
 715
 716         if (!ext4_dir_dx_csum_verify(inode_ref, (void *)root_block.data)) {
 717                 ext4_dbg(DEBUG_DIR_IDX,
 718                          DBG_WARN "HTree root checksum failed."
 719                          "Inode: %" PRIu32", "
 720                          "Block: %" PRIu32"\n",
 721                          inode_ref->index,
 722                          (uint32_t)0);
 723         }
 724
 725         /* Initialize hash info (compute hash value) */
 726         struct ext4_hash_info hinfo;
 727         rc = ext4_dir_hinfo_init(&hinfo, &root_block, &fs->sb, name_len, name);
 728         if (rc != EOK) {
 729                 ext4_block_set(fs->bdev, &root_block);
 730                 return EXT4_ERR_BAD_DX_DIR;
 731         }
 732
 733         /*
 734          * Hardcoded number 2 means maximum height of index tree,
 735          * specified in the Linux driver.
 736          */
 737         struct ext4_dir_idx_block dx_blocks[2];
 738         struct ext4_dir_idx_block *dx_block;
 739         struct ext4_dir_idx_block *tmp;
 740
 741         rc = ext4_dir_dx_get_leaf(&hinfo, inode_ref, &root_block, &dx_block,
 742                                   dx_blocks);
 743         if (rc != EOK) {
 744                 ext4_block_set(fs->bdev, &root_block);
 745                 return EXT4_ERR_BAD_DX_DIR;
 746         }
 747
 748         do {
 749                 /* Load leaf block */
 750                 uint32_t leaf_blk_idx;
 751                 ext4_fsblk_t leaf_block_addr;
 752                 struct ext4_block b;
 753
 754                 leaf_blk_idx = ext4_dir_dx_entry_get_block(dx_block->position);
 755                 rc = ext4_fs_get_inode_data_block_index(inode_ref, leaf_blk_idx,
 756                                                        &leaf_block_addr, false);
 757                 if (rc != EOK)
 758                         goto cleanup;
 759
 760                 rc = ext4_block_get(fs->bdev, &b, leaf_block_addr);
 761                 if (rc != EOK)
 762                         goto cleanup;
 763
 764                 if (!ext4_dir_csum_verify(inode_ref, (void *)b.data)) {
 765                         ext4_dbg(DEBUG_DIR_IDX,
 766                                  DBG_WARN "HTree leaf block checksum failed."
 767                                  "Inode: %" PRIu32", "
 768                                  "Block: %" PRIu32"\n",
 769                                  inode_ref->index,
 770                                  leaf_blk_idx);
 771                 }
 772
 773                 /* Linear search inside block */
 774                 struct ext4_dir_en *de;
 775                 rc = ext4_dir_find_in_block(&b, &fs->sb, name_len, name, &de);
 776
 777                 /* Found => return it */
 778                 if (rc == EOK) {
 779                         result->block = b;
 780                         result->dentry = de;
 781                         goto cleanup;
 782                 }
 783
 784                 /* Not found, leave untouched */
 785                 rc2 = ext4_block_set(fs->bdev, &b);
 786                 if (rc2 != EOK)
 787                         goto cleanup;
 788
 789                 if (rc != ENOENT)
 790                         goto cleanup;
 791
 792                 /* check if the next block could be checked */
 793                 rc = ext4_dir_dx_next_block(inode_ref, hinfo.hash, dx_block,
 794                                             &dx_blocks[0]);
 795                 if (rc < 0)
 796                         goto cleanup;
 797         } while (rc == ENOENT);
 798
 799         /* Entry not found */
 800         rc = ENOENT;
 801
 802 cleanup:
 803         /* The whole path must be released (preventing memory leak) */
 804         tmp = dx_blocks;
 805
 806         while (tmp <= dx_block) {
 807                 rc2 = ext4_block_set(fs->bdev, &tmp->b);
 808                 if (rc == EOK && rc2 != EOK)
 809                         rc = rc2;
 810                 ++tmp;
 811         }
 812
 813         return rc;
 814 }
 815
 816 #if CONFIG_DIR_INDEX_COMB_SORT
 817 #define SWAP_ENTRY(se1, se2)                                                   \
 818         do {                                                                   \
 819                 struct ext4_dx_sort_entry tmp = se1;                           \
 820                 se1 = se2;                                                     \
 821                 se2 = tmp;                                                     \
 822         \
 823 } while (0)
 824
 825 static void comb_sort(struct ext4_dx_sort_entry *se, uint32_t count)
 826 {
 827         struct ext4_dx_sort_entry *p, *q, *top = se + count - 1;
 828         bool more;
 829         /* Combsort */
 830         while (count > 2) {
 831                 count = (count * 10) / 13;
 832                 if (count - 9 < 2)
 833                         count = 11;
 834                 for (p = top, q = p - count; q >= se; p--, q--)
 835                         if (p->hash < q->hash)
 836                                 SWAP_ENTRY(*p, *q);
 837         }
 838         /* Bubblesort */
 839         do {
 840                 more = 0;
 841                 q = top;
 842                 while (q-- > se) {
 843                         if (q[1].hash >= q[0].hash)
 844                                 continue;
 845                         SWAP_ENTRY(*(q + 1), *q);
 846                         more = 1;
 847                 }
 848         } while (more);
 849 }
 850 #else
 851
 852 /**@brief  Compare function used to pass in quicksort implementation.
 853  *         It can compare two entries by hash value.
 854  * @param arg1  First entry
 855  * @param arg2  Second entry
 856  * @param dummy Unused parameter, can be NULL
 857  *
 858  * @return Classic compare result
 859  *         (0: equal, -1: arg1 < arg2, 1: arg1 > arg2)
 860  */
 861 static int ext4_dir_dx_entry_comparator(const void *arg1, const void *arg2)
 862 {
 863         struct ext4_dx_sort_entry *entry1 = (void *)arg1;
 864         struct ext4_dx_sort_entry *entry2 = (void *)arg2;
 865
 866         if (entry1->hash == entry2->hash)
 867                 return 0;
 868
 869         if (entry1->hash < entry2->hash)
 870                 return -1;
 871         else
 872                 return 1;
 873 }
 874 #endif
 875
 876 /**@brief  Insert new index entry to block.
 877  *         Note that space for new entry must be checked by caller.
 878  * @param inode_ref   Directory i-node
 879  * @param index_block Block where to insert new entry
 880  * @param hash        Hash value covered by child node
 881  * @param iblock      Logical number of child block
 882  *
 883  */
 884 static void
 885 ext4_dir_dx_insert_entry(struct ext4_inode_ref *inode_ref __unused,
 886                          struct ext4_dir_idx_block *index_block,
 887                          uint32_t hash, uint32_t iblock)
 888 {
 889         struct ext4_dir_idx_entry *old_index_entry = index_block->position;
 890         struct ext4_dir_idx_entry *new_index_entry = old_index_entry + 1;
 891         struct ext4_dir_idx_climit *climit = (void *)index_block->entries;
 892         struct ext4_dir_idx_entry *start_index = index_block->entries;
 893         uint32_t count = ext4_dir_dx_climit_get_count(climit);
 894
 895         size_t bytes;
 896         bytes = (uint8_t *)(start_index + count) - (uint8_t *)(new_index_entry);
 897
 898         memmove(new_index_entry + 1, new_index_entry, bytes);
 899
 900         ext4_dir_dx_entry_set_block(new_index_entry, iblock);
 901         ext4_dir_dx_entry_set_hash(new_index_entry, hash);
 902         ext4_dir_dx_climit_set_count(climit, count + 1);
 903         ext4_dir_set_dx_csum(inode_ref, (void *)index_block->b.data);
 904         index_block->b.dirty = true;
 905 }
 906
 907 /**@brief Split directory entries to two parts preventing node overflow.
 908  * @param inode_ref      Directory i-node
 909  * @param hinfo          Hash info
 910  * @param old_data_block Block with data to be split
 911  * @param index_block    Block where index entries are located
 912  * @param new_data_block Output value for newly allocated data block
 913  */
 914 static int ext4_dir_dx_split_data(struct ext4_inode_ref *inode_ref,
 915                                   struct ext4_hash_info *hinfo,
 916                                   struct ext4_block *old_data_block,
 917                                   struct ext4_dir_idx_block *index_block,
 918                                   struct ext4_block *new_data_block)
 919 {
 920         int rc = EOK;
 921         struct ext4_sblock *sb = &inode_ref->fs->sb;
 922         uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
 923
 924         /* Allocate buffer for directory entries */
 925         uint8_t *entry_buffer = malloc(block_size);
 926         if (entry_buffer == NULL)
 927                 return ENOMEM;
 928
 929         /* dot entry has the smallest size available */
 930         uint32_t max_ecnt = block_size / sizeof(struct ext4_dir_idx_dot_en);
 931
 932         /* Allocate sort entry */
 933         struct ext4_dx_sort_entry *sort;
 934
 935         sort = malloc(max_ecnt * sizeof(struct ext4_dx_sort_entry));
 936         if (sort == NULL) {
 937                 free(entry_buffer);
 938                 return ENOMEM;
 939         }
 940
 941         uint32_t idx = 0;
 942         uint32_t real_size = 0;
 943
 944         /* Initialize hinfo */
 945         struct ext4_hash_info hinfo_tmp;
 946         memcpy(&hinfo_tmp, hinfo, sizeof(struct ext4_hash_info));
 947
 948         /* Load all valid entries to the buffer */
 949         struct ext4_dir_en *de = (void *)old_data_block->data;
 950         uint8_t *entry_buffer_ptr = entry_buffer;
 951         while ((void *)de < (void *)(old_data_block->data + block_size)) {
 952                 /* Read only valid entries */
 953                 if (ext4_dir_en_get_inode(de) && de->name_len) {
 954                         uint8_t len = ext4_dir_en_get_name_len(sb, de);
 955                         rc = ext4_dir_dx_hash_string(&hinfo_tmp, len,
 956                                                      (char *)de->name);
 957                         if (rc != EOK) {
 958                                 free(sort);
 959                                 free(entry_buffer);
 960                                 return rc;
 961                         }
 962
 963                         uint32_t rec_len = 8 + len;
 964                         if ((rec_len % 4) != 0)
 965                                 rec_len += 4 - (rec_len % 4);
 966
 967                         memcpy(entry_buffer_ptr, de, rec_len);
 968
 969                         sort[idx].dentry = entry_buffer_ptr;
 970                         sort[idx].rec_len = rec_len;
 971                         sort[idx].hash = hinfo_tmp.hash;
 972
 973                         entry_buffer_ptr += rec_len;
 974                         real_size += rec_len;
 975                         idx++;
 976                 }
 977
 978                 size_t elen = ext4_dir_en_get_entry_len(de);
 979                 de = (void *)((uint8_t *)de + elen);
 980         }
 981
 982 /* Sort all entries */
 983 #if CONFIG_DIR_INDEX_COMB_SORT
 984         comb_sort(sort, idx);
 985 #else
 986         qsort(sort, idx, sizeof(struct ext4_dx_sort_entry),
 987               ext4_dir_dx_entry_comparator);
 988 #endif
 989         /* Allocate new block for store the second part of entries */
 990         ext4_fsblk_t new_fblock;
 991         uint32_t new_iblock;
 992         rc = ext4_fs_append_inode_block(inode_ref, &new_fblock, &new_iblock);
 993         if (rc != EOK) {
 994                 free(sort);
 995                 free(entry_buffer);
 996                 return rc;
 997         }
 998
 999         /* Load new block */
1000         struct ext4_block new_data_block_tmp;
1001         rc = ext4_block_get_noread(inode_ref->fs->bdev, &new_data_block_tmp,
1002                                    new_fblock);
1003         if (rc != EOK) {
1004                 free(sort);
1005                 free(entry_buffer);
1006                 return rc;
1007         }
1008
1009         /*
1010          * Distribute entries to two blocks (by size)
1011          * - compute the half
1012          */
1013         uint32_t new_hash = 0;
1014         uint32_t current_size = 0;
1015         uint32_t mid = 0;
1016         uint32_t i;
1017         for (i = 0; i < idx; ++i) {
1018                 if ((current_size + sort[i].rec_len) > (block_size / 2)) {
1019                         new_hash = sort[i].hash;
1020                         mid = i;
1021                         break;
1022                 }
1023
1024                 current_size += sort[i].rec_len;
1025         }
1026
1027         /* Check hash collision */
1028         uint32_t continued = 0;
1029         if (new_hash == sort[mid - 1].hash)
1030                 continued = 1;
1031
1032         uint32_t off = 0;
1033         void *ptr;
1034         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
1035                 block_size -= sizeof(struct ext4_dir_entry_tail);
1036
1037         /* First part - to the old block */
1038         for (i = 0; i < mid; ++i) {
1039                 ptr = old_data_block->data + off;
1040                 memcpy(ptr, sort[i].dentry, sort[i].rec_len);
1041
1042                 struct ext4_dir_en *t = ptr;
1043                 if (i < (mid - 1))
1044                         ext4_dir_en_set_entry_len(t, sort[i].rec_len);
1045                 else
1046                         ext4_dir_en_set_entry_len(t, block_size - off);
1047
1048                 off += sort[i].rec_len;
1049         }
1050
1051         /* Second part - to the new block */
1052         off = 0;
1053         for (i = mid; i < idx; ++i) {
1054                 ptr = new_data_block_tmp.data + off;
1055                 memcpy(ptr, sort[i].dentry, sort[i].rec_len);
1056
1057                 struct ext4_dir_en *t = ptr;
1058                 if (i < (idx - 1))
1059                         ext4_dir_en_set_entry_len(t, sort[i].rec_len);
1060                 else
1061                         ext4_dir_en_set_entry_len(t, block_size - off);
1062
1063                 off += sort[i].rec_len;
1064         }
1065
1066         block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
1067
1068         /* Do some steps to finish operation */
1069         sb = &inode_ref->fs->sb;
1070         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
1071                 struct ext4_dir_entry_tail *t;
1072
1073                 t = EXT4_DIRENT_TAIL(old_data_block->data, block_size);
1074                 ext4_dir_init_entry_tail(t);
1075                 t = EXT4_DIRENT_TAIL(new_data_block_tmp.data, block_size);
1076                 ext4_dir_init_entry_tail(t);
1077         }
1078         ext4_dir_set_csum(inode_ref, (void *)old_data_block->data);
1079         ext4_dir_set_csum(inode_ref, (void *)new_data_block_tmp.data);
1080         old_data_block->dirty = true;
1081         new_data_block_tmp.dirty = true;
1082
1083         free(sort);
1084         free(entry_buffer);
1085
1086         ext4_dir_dx_insert_entry(inode_ref, index_block, new_hash + continued,
1087                                 new_iblock);
1088
1089         *new_data_block = new_data_block_tmp;
1090         return EOK;
1091 }
1092
1093 /**@brief  Split index node and maybe some parent nodes in the tree hierarchy.
1094  * @param inode_ref Directory i-node
1095  * @param dx_blocks Array with path from root to leaf node
1096  * @param dx_block  Leaf block to be split if needed
1097  * @return Error code
1098  */
1099 static int
1100 ext4_dir_dx_split_index(struct ext4_inode_ref *ino_ref,
1101                         struct ext4_dir_idx_block *dx_blks,
1102                         struct ext4_dir_idx_block *dxb,
1103                         struct ext4_dir_idx_block **new_dx_block)
1104 {
1105         struct ext4_sblock *sb = &ino_ref->fs->sb;
1106         struct ext4_dir_idx_entry *e;
1107         int r;
1108
1109         uint32_t block_size = ext4_sb_get_block_size(&ino_ref->fs->sb);
1110         uint32_t entry_space = block_size - sizeof(struct ext4_fake_dir_entry);
1111         uint32_t node_limit =  entry_space / sizeof(struct ext4_dir_idx_entry);
1112
1113         bool meta_csum = ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM);
1114
1115         if (dxb == dx_blks)
1116                 e = ((struct ext4_dir_idx_root *)dxb->b.data)->en;
1117         else
1118                 e = ((struct ext4_dir_idx_node *)dxb->b.data)->entries;
1119
1120         struct ext4_dir_idx_climit *climit = (struct ext4_dir_idx_climit *)e;
1121
1122         uint16_t leaf_limit = ext4_dir_dx_climit_get_limit(climit);
1123         uint16_t leaf_count = ext4_dir_dx_climit_get_count(climit);
1124
1125         /* Check if is necessary to split index block */
1126         if (leaf_limit == leaf_count) {
1127                 struct ext4_dir_idx_entry *ren;
1128                 ptrdiff_t levels = dxb - dx_blks;
1129
1130                 ren = ((struct ext4_dir_idx_root *)dx_blks[0].b.data)->en;
1131                 struct ext4_dir_idx_climit *rclimit = (void *)ren;
1132                 uint16_t root_limit = ext4_dir_dx_climit_get_limit(rclimit);
1133                 uint16_t root_count = ext4_dir_dx_climit_get_count(rclimit);
1134
1135
1136                 /* Linux limitation */
1137                 if ((levels > 0) && (root_limit == root_count))
1138                         return ENOSPC;
1139
1140                 /* Add new block to directory */
1141                 ext4_fsblk_t new_fblk;
1142                 uint32_t new_iblk;
1143                 r = ext4_fs_append_inode_block(ino_ref, &new_fblk, &new_iblk);
1144                 if (r != EOK)
1145                         return r;
1146
1147                 /* load new block */
1148                 struct ext4_block b;
1149                 r = ext4_block_get_noread(ino_ref->fs->bdev, &b, new_fblk);
1150                 if (r != EOK)
1151                         return r;
1152
1153                 struct ext4_dir_idx_node *new_node = (void *)b.data;
1154                 struct ext4_dir_idx_entry *new_en = new_node->entries;
1155
1156                 memset(&new_node->fake, 0, sizeof(struct ext4_fake_dir_entry));
1157                 new_node->fake.entry_length = block_size;
1158
1159                 /* Split leaf node */
1160                 if (levels > 0) {
1161                         uint32_t count_left = leaf_count / 2;
1162                         uint32_t count_right = leaf_count - count_left;
1163                         uint32_t hash_right;
1164                         size_t sz;
1165
1166                         struct ext4_dir_idx_climit *left_climit;
1167                         struct ext4_dir_idx_climit *right_climit;
1168
1169                         hash_right = ext4_dir_dx_entry_get_hash(e + count_left);
1170                         /* Copy data to new node */
1171                         sz = count_right * sizeof(struct ext4_dir_idx_entry);
1172                         memcpy(new_en, e + count_left, sz);
1173
1174                         /* Initialize new node */
1175                         left_climit = (struct ext4_dir_idx_climit *)e;
1176                         right_climit = (struct ext4_dir_idx_climit *)new_en;
1177
1178                         ext4_dir_dx_climit_set_count(left_climit, count_left);
1179                         ext4_dir_dx_climit_set_count(right_climit, count_right);
1180
1181                         if (meta_csum)
1182                                 entry_space -= sizeof(struct ext4_dir_idx_tail);
1183
1184                         ext4_dir_dx_climit_set_limit(right_climit, node_limit);
1185
1186                         /* Which index block is target for new entry */
1187                         uint32_t position_index =
1188                             (dxb->position - dxb->entries);
1189                         if (position_index >= count_left) {
1190                                 ext4_dir_set_dx_csum(
1191                                                 ino_ref,
1192                                                 (struct ext4_dir_en *)
1193                                                 dxb->b.data);
1194                                 dxb->b.dirty = true;
1195
1196                                 struct ext4_block block_tmp = dxb->b;
1197
1198                                 dxb->b = b;
1199
1200                                 dxb->position =
1201                                     new_en + position_index - count_left;
1202                                 dxb->entries = new_en;
1203
1204                                 b = block_tmp;
1205                         }
1206
1207                         /* Finally insert new entry */
1208                         ext4_dir_dx_insert_entry(ino_ref, dx_blks, hash_right,
1209                                                  new_iblk);
1210                         ext4_dir_set_dx_csum(ino_ref, (void *)dx_blks[0].b.data);
1211                         ext4_dir_set_dx_csum(ino_ref, (void *)dx_blks[1].b.data);
1212                         dx_blks[0].b.dirty = true;
1213                         dx_blks[1].b.dirty = true;
1214
1215                         ext4_dir_set_dx_csum(ino_ref, (void *)b.data);
1216                         b.dirty = true;
1217                         return ext4_block_set(ino_ref->fs->bdev, &b);
1218                 } else {
1219                         size_t sz;
1220                         /* Copy data from root to child block */
1221                         sz = leaf_count * sizeof(struct ext4_dir_idx_entry);
1222                         memcpy(new_en, e, sz);
1223
1224                         struct ext4_dir_idx_climit *new_climit = (void*)new_en;
1225                         if (meta_csum)
1226                                 entry_space -= sizeof(struct ext4_dir_idx_tail);
1227
1228                         ext4_dir_dx_climit_set_limit(new_climit, node_limit);
1229
1230                         /* Set values in root node */
1231                         struct ext4_dir_idx_climit *new_root_climit = (void *)e;
1232
1233                         ext4_dir_dx_climit_set_count(new_root_climit, 1);
1234                         ext4_dir_dx_entry_set_block(e, new_iblk);
1235
1236                         struct ext4_dir_idx_root *r = (void *)dx_blks[0].b.data;
1237                         r->info.indirect_levels = 1;
1238
1239                         /* Add new entry to the path */
1240                         dxb = dx_blks + 1;
1241                         dxb->position = dx_blks->position - e + new_en;
1242                         dxb->entries = new_en;
1243                         dxb->b = b;
1244                         *new_dx_block = dxb;
1245
1246                         ext4_dir_set_dx_csum(ino_ref, (void *)dx_blks[0].b.data);
1247                         ext4_dir_set_dx_csum(ino_ref, (void *)dx_blks[1].b.data);
1248                         dx_blks[0].b.dirty = true;
1249                         dx_blks[1].b.dirty = true;
1250                 }
1251         }
1252
1253         return EOK;
1254 }
1255
1256 int ext4_dir_dx_add_entry(struct ext4_inode_ref *parent,
1257                           struct ext4_inode_ref *child, const char *name)
1258 {
1259         int rc2 = EOK;
1260         int r;
1261         /* Get direct block 0 (index root) */
1262         ext4_fsblk_t rblock_addr;
1263         r =  ext4_fs_get_inode_data_block_index(parent, 0, &rblock_addr, false);
1264         if (r != EOK)
1265                 return r;
1266
1267         struct ext4_fs *fs = parent->fs;
1268         struct ext4_block root_blk;
1269
1270         r = ext4_block_get(fs->bdev, &root_blk, rblock_addr);
1271         if (r != EOK)
1272                 return r;
1273
1274         if (!ext4_dir_dx_csum_verify(parent, (void*)root_blk.data)) {
1275                 ext4_dbg(DEBUG_DIR_IDX,
1276                          DBG_WARN "HTree root checksum failed."
1277                          "Inode: %" PRIu32", "
1278                          "Block: %" PRIu32"\n",
1279                          parent->index,
1280                          (uint32_t)0);
1281         }
1282
1283         /* Initialize hinfo structure (mainly compute hash) */
1284         uint32_t name_len = strlen(name);
1285         struct ext4_hash_info hinfo;
1286         r = ext4_dir_hinfo_init(&hinfo, &root_blk, &fs->sb, name_len, name);
1287         if (r != EOK) {
1288                 ext4_block_set(fs->bdev, &root_blk);
1289                 return EXT4_ERR_BAD_DX_DIR;
1290         }
1291
1292         /*
1293          * Hardcoded number 2 means maximum height of index
1294          * tree defined in Linux.
1295          */
1296         struct ext4_dir_idx_block dx_blks[2];
1297         struct ext4_dir_idx_block *dx_blk;
1298         struct ext4_dir_idx_block *dx_it;
1299
1300         r = ext4_dir_dx_get_leaf(&hinfo, parent, &root_blk, &dx_blk, dx_blks);
1301         if (r != EOK) {
1302                 r = EXT4_ERR_BAD_DX_DIR;
1303                 goto release_index;
1304         }
1305
1306         /* Try to insert to existing data block */
1307         uint32_t leaf_block_idx = ext4_dir_dx_entry_get_block(dx_blk->position);
1308         ext4_fsblk_t leaf_block_addr;
1309         r = ext4_fs_get_inode_data_block_index(parent, leaf_block_idx,
1310                                                 &leaf_block_addr, false);
1311         if (r != EOK)
1312                 goto release_index;
1313
1314         /*
1315          * Check if there is needed to split index node
1316          * (and recursively also parent nodes)
1317          */
1318         r = ext4_dir_dx_split_index(parent, dx_blks, dx_blk, &dx_blk);
1319         if (r != EOK)
1320                 goto release_target_index;
1321
1322         struct ext4_block target_block;
1323         r = ext4_block_get(fs->bdev, &target_block, leaf_block_addr);
1324         if (r != EOK)
1325                 goto release_index;
1326
1327         if (!ext4_dir_csum_verify(parent,(void *)target_block.data)) {
1328                 ext4_dbg(DEBUG_DIR_IDX,
1329                                 DBG_WARN "HTree leaf block checksum failed."
1330                                 "Inode: %" PRIu32", "
1331                                 "Block: %" PRIu32"\n",
1332                                 parent->index,
1333                                 leaf_block_idx);
1334         }
1335
1336         /* Check if insert operation passed */
1337         r = ext4_dir_try_insert_entry(&fs->sb, parent, &target_block, child,
1338                                         name, name_len);
1339         if (r == EOK)
1340                 goto release_target_index;
1341
1342         /* Split entries to two blocks (includes sorting by hash value) */
1343         struct ext4_block new_block;
1344         r = ext4_dir_dx_split_data(parent, &hinfo, &target_block, dx_blk,
1345                                     &new_block);
1346         if (r != EOK) {
1347                 rc2 = r;
1348                 goto release_target_index;
1349         }
1350
1351         /* Where to save new entry */
1352         uint32_t blk_hash = ext4_dir_dx_entry_get_hash(dx_blk->position + 1);
1353         if (hinfo.hash >= blk_hash)
1354                 r = ext4_dir_try_insert_entry(&fs->sb, parent, &new_block,
1355                                                 child, name, name_len);
1356         else
1357                 r = ext4_dir_try_insert_entry(&fs->sb, parent, &target_block,
1358                                                 child, name, name_len);
1359
1360         /* Cleanup */
1361         r = ext4_block_set(fs->bdev, &new_block);
1362         if (r != EOK)
1363                 return r;
1364
1365 /* Cleanup operations */
1366
1367 release_target_index:
1368         rc2 = r;
1369
1370         r = ext4_block_set(fs->bdev, &target_block);
1371         if (r != EOK)
1372                 return r;
1373
1374 release_index:
1375         if (r != EOK)
1376                 rc2 = r;
1377
1378         dx_it = dx_blks;
1379
1380         while (dx_it <= dx_blk) {
1381                 r = ext4_block_set(fs->bdev, &dx_it->b);
1382                 if (r != EOK)
1383                         return r;
1384
1385                 dx_it++;
1386         }
1387
1388         return rc2;
1389 }
1390
1391 int ext4_dir_dx_reset_parent_inode(struct ext4_inode_ref *dir,
1392                                    uint32_t parent_inode)
1393 {
1394         /* Load block 0, where will be index root located */
1395         ext4_fsblk_t fblock;
1396         int rc = ext4_fs_get_inode_data_block_index(dir, 0, &fblock, false);
1397         if (rc != EOK)
1398                 return rc;
1399
1400         struct ext4_block block;
1401         rc = ext4_block_get(dir->fs->bdev, &block, fblock);
1402         if (rc != EOK)
1403                 return rc;
1404
1405         if (!ext4_dir_dx_csum_verify(dir, (void *)block.data)) {
1406                 ext4_dbg(DEBUG_DIR_IDX,
1407                          DBG_WARN "HTree root checksum failed."
1408                          "Inode: %" PRIu32", "
1409                          "Block: %" PRIu32"\n",
1410                          dir->index,
1411                          (uint32_t)0);
1412         }
1413
1414         /* Initialize pointers to data structures */
1415         struct ext4_dir_idx_root *root = (void *)block.data;
1416
1417         /* Fill the inode field with a new parent ino. */
1418         ext4_dx_dot_en_set_inode(&root->dots[1], parent_inode);
1419
1420         ext4_dir_set_dx_csum(dir, (void *)block.data);
1421         block.dirty = true;
1422
1423         return ext4_block_set(dir->fs->bdev, &block);
1424 }
1425
1426 /**
1427  * @}
1428  */