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_dblk(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_dblk(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         ext4_bcache_set_dirty(new_block.buf);
 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         ext4_bcache_set_dirty(block.buf);
 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 fblk;
 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 n_blk = ext4_dir_dx_entry_get_block(at);
 576
 577                 ind_level--;
 578
 579                 r = ext4_fs_get_inode_dblk_idx(inode_ref, n_blk, &fblk, false);
 580                 if (r != EOK)
 581                         return r;
 582
 583                 r = ext4_block_get(inode_ref->fs->bdev, tmp_blk, fblk);
 584                 if (r != EOK)
 585                         return r;
 586
 587                 entries = ((struct ext4_dir_idx_node *)tmp_blk->data)->entries;
 588                 limit = ext4_dir_dx_climit_get_limit((void *)entries);
 589
 590                 entry_space = block_size - sizeof(struct ext4_fake_dir_entry);
 591                 if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
 592                         entry_space -= sizeof(struct ext4_dir_idx_tail);
 593
 594                 entry_space = entry_space / sizeof(struct ext4_dir_idx_entry);
 595
 596                 if (limit != entry_space) {
 597                         ext4_block_set(inode_ref->fs->bdev, tmp_blk);
 598                         return EXT4_ERR_BAD_DX_DIR;
 599                 }
 600
 601                 if (!ext4_dir_dx_csum_verify(inode_ref, (void *)tmp_blk->data)) {
 602                         ext4_dbg(DEBUG_DIR_IDX,
 603                                         DBG_WARN "HTree checksum failed."
 604                                         "Inode: %" PRIu32", "
 605                                         "Block: %" PRIu32"\n",
 606                                         inode_ref->index,
 607                                         n_blk);
 608                 }
 609
 610                 ++tmp_dx_blk;
 611         }
 612
 613         /* Unreachable */
 614         return EOK;
 615 }
 616
 617 /**@brief Check if the the next block would be checked during entry search.
 618  * @param inode_ref Directory i-node
 619  * @param hash      Hash value to check
 620  * @param dx_block  Current block
 621  * @param dx_blocks Array with path from root to leaf node
 622  * @return Standard Error code
 623  */
 624 static int ext4_dir_dx_next_block(struct ext4_inode_ref *inode_ref,
 625                                   uint32_t hash,
 626                                   struct ext4_dir_idx_block *dx_block,
 627                                   struct ext4_dir_idx_block *dx_blocks)
 628 {
 629         int r;
 630         uint32_t num_handles = 0;
 631         ext4_fsblk_t blk_adr;
 632         struct ext4_dir_idx_block *p = dx_block;
 633
 634         /* Try to find data block with next bunch of entries */
 635         while (true) {
 636                 uint16_t cnt = ext4_dir_dx_climit_get_count((void *)p->entries);
 637
 638                 p->position++;
 639                 if (p->position < p->entries + cnt)
 640                         break;
 641
 642                 if (p == dx_blocks)
 643                         return EOK;
 644
 645                 num_handles++;
 646                 p--;
 647         }
 648
 649         /* Check hash collision (if not occurred - no next block cannot be
 650          * used)*/
 651         uint32_t current_hash = ext4_dir_dx_entry_get_hash(p->position);
 652         if ((hash & 1) == 0) {
 653                 if ((current_hash & ~1) != hash)
 654                         return 0;
 655         }
 656
 657         /* Fill new path */
 658         while (num_handles--) {
 659                 uint32_t blk = ext4_dir_dx_entry_get_block(p->position);
 660                 r = ext4_fs_get_inode_dblk_idx(inode_ref, blk, &blk_adr, false);
 661                 if (r != EOK)
 662                         return r;
 663
 664                 struct ext4_block b;
 665                 r = ext4_block_get(inode_ref->fs->bdev, &b, blk_adr);
 666                 if (r != EOK)
 667                         return r;
 668
 669                 if (!ext4_dir_dx_csum_verify(inode_ref, (void *)b.data)) {
 670                         ext4_dbg(DEBUG_DIR_IDX,
 671                                         DBG_WARN "HTree checksum failed."
 672                                         "Inode: %" PRIu32", "
 673                                         "Block: %" PRIu32"\n",
 674                                         inode_ref->index,
 675                                         blk);
 676                 }
 677
 678                 p++;
 679
 680                 /* Don't forget to put old block (prevent memory leak) */
 681                 r = ext4_block_set(inode_ref->fs->bdev, &p->b);
 682                 if (r != EOK)
 683                         return r;
 684
 685                 memcpy(&p->b, &b, sizeof(b));
 686                 p->entries = ((struct ext4_dir_idx_node *)b.data)->entries;
 687                 p->position = p->entries;
 688         }
 689
 690         return ENOENT;
 691 }
 692
 693 int ext4_dir_dx_find_entry(struct ext4_dir_search_result *result,
 694                            struct ext4_inode_ref *inode_ref, size_t name_len,
 695                            const char *name)
 696 {
 697         /* Load direct block 0 (index root) */
 698         ext4_fsblk_t root_block_addr;
 699         int rc2;
 700         int rc;
 701         rc = ext4_fs_get_inode_dblk_idx(inode_ref,  0, &root_block_addr, false);
 702         if (rc != EOK)
 703                 return rc;
 704
 705         struct ext4_fs *fs = inode_ref->fs;
 706
 707         struct ext4_block root_block;
 708         rc = ext4_block_get(fs->bdev, &root_block, root_block_addr);
 709         if (rc != EOK)
 710                 return rc;
 711
 712         if (!ext4_dir_dx_csum_verify(inode_ref, (void *)root_block.data)) {
 713                 ext4_dbg(DEBUG_DIR_IDX,
 714                          DBG_WARN "HTree root checksum failed."
 715                          "Inode: %" PRIu32", "
 716                          "Block: %" PRIu32"\n",
 717                          inode_ref->index,
 718                          (uint32_t)0);
 719         }
 720
 721         /* Initialize hash info (compute hash value) */
 722         struct ext4_hash_info hinfo;
 723         rc = ext4_dir_hinfo_init(&hinfo, &root_block, &fs->sb, name_len, name);
 724         if (rc != EOK) {
 725                 ext4_block_set(fs->bdev, &root_block);
 726                 return EXT4_ERR_BAD_DX_DIR;
 727         }
 728
 729         /*
 730          * Hardcoded number 2 means maximum height of index tree,
 731          * specified in the Linux driver.
 732          */
 733         struct ext4_dir_idx_block dx_blocks[2];
 734         struct ext4_dir_idx_block *dx_block;
 735         struct ext4_dir_idx_block *tmp;
 736
 737         rc = ext4_dir_dx_get_leaf(&hinfo, inode_ref, &root_block, &dx_block,
 738                                   dx_blocks);
 739         if (rc != EOK) {
 740                 ext4_block_set(fs->bdev, &root_block);
 741                 return EXT4_ERR_BAD_DX_DIR;
 742         }
 743
 744         do {
 745                 /* Load leaf block */
 746                 uint32_t leaf_blk_idx;
 747                 ext4_fsblk_t leaf_block_addr;
 748                 struct ext4_block b;
 749
 750                 leaf_blk_idx = ext4_dir_dx_entry_get_block(dx_block->position);
 751                 rc = ext4_fs_get_inode_dblk_idx(inode_ref, leaf_blk_idx,
 752                                                 &leaf_block_addr, false);
 753                 if (rc != EOK)
 754                         goto cleanup;
 755
 756                 rc = ext4_block_get(fs->bdev, &b, leaf_block_addr);
 757                 if (rc != EOK)
 758                         goto cleanup;
 759
 760                 if (!ext4_dir_csum_verify(inode_ref, (void *)b.data)) {
 761                         ext4_dbg(DEBUG_DIR_IDX,
 762                                  DBG_WARN "HTree leaf block checksum failed."
 763                                  "Inode: %" PRIu32", "
 764                                  "Block: %" PRIu32"\n",
 765                                  inode_ref->index,
 766                                  leaf_blk_idx);
 767                 }
 768
 769                 /* Linear search inside block */
 770                 struct ext4_dir_en *de;
 771                 rc = ext4_dir_find_in_block(&b, &fs->sb, name_len, name, &de);
 772
 773                 /* Found => return it */
 774                 if (rc == EOK) {
 775                         result->block = b;
 776                         result->dentry = de;
 777                         goto cleanup;
 778                 }
 779
 780                 /* Not found, leave untouched */
 781                 rc2 = ext4_block_set(fs->bdev, &b);
 782                 if (rc2 != EOK)
 783                         goto cleanup;
 784
 785                 if (rc != ENOENT)
 786                         goto cleanup;
 787
 788                 /* check if the next block could be checked */
 789                 rc = ext4_dir_dx_next_block(inode_ref, hinfo.hash, dx_block,
 790                                             &dx_blocks[0]);
 791                 if (rc < 0)
 792                         goto cleanup;
 793         } while (rc == ENOENT);
 794
 795         /* Entry not found */
 796         rc = ENOENT;
 797
 798 cleanup:
 799         /* The whole path must be released (preventing memory leak) */
 800         tmp = dx_blocks;
 801
 802         while (tmp <= dx_block) {
 803                 rc2 = ext4_block_set(fs->bdev, &tmp->b);
 804                 if (rc == EOK && rc2 != EOK)
 805                         rc = rc2;
 806                 ++tmp;
 807         }
 808
 809         return rc;
 810 }
 811
 812 #if CONFIG_DIR_INDEX_COMB_SORT
 813 #define SWAP_ENTRY(se1, se2)                                                   \
 814         do {                                                                   \
 815                 struct ext4_dx_sort_entry tmp = se1;                           \
 816                 se1 = se2;                                                     \
 817                 se2 = tmp;                                                     \
 818         \
 819 } while (0)
 820
 821 static void comb_sort(struct ext4_dx_sort_entry *se, uint32_t count)
 822 {
 823         struct ext4_dx_sort_entry *p, *q, *top = se + count - 1;
 824         bool more;
 825         /* Combsort */
 826         while (count > 2) {
 827                 count = (count * 10) / 13;
 828                 if (count - 9 < 2)
 829                         count = 11;
 830                 for (p = top, q = p - count; q >= se; p--, q--)
 831                         if (p->hash < q->hash)
 832                                 SWAP_ENTRY(*p, *q);
 833         }
 834         /* Bubblesort */
 835         do {
 836                 more = 0;
 837                 q = top;
 838                 while (q-- > se) {
 839                         if (q[1].hash >= q[0].hash)
 840                                 continue;
 841                         SWAP_ENTRY(*(q + 1), *q);
 842                         more = 1;
 843                 }
 844         } while (more);
 845 }
 846 #else
 847
 848 /**@brief  Compare function used to pass in quicksort implementation.
 849  *         It can compare two entries by hash value.
 850  * @param arg1  First entry
 851  * @param arg2  Second entry
 852  * @param dummy Unused parameter, can be NULL
 853  *
 854  * @return Classic compare result
 855  *         (0: equal, -1: arg1 < arg2, 1: arg1 > arg2)
 856  */
 857 static int ext4_dir_dx_entry_comparator(const void *arg1, const void *arg2)
 858 {
 859         struct ext4_dx_sort_entry *entry1 = (void *)arg1;
 860         struct ext4_dx_sort_entry *entry2 = (void *)arg2;
 861
 862         if (entry1->hash == entry2->hash)
 863                 return 0;
 864
 865         if (entry1->hash < entry2->hash)
 866                 return -1;
 867         else
 868                 return 1;
 869 }
 870 #endif
 871
 872 /**@brief  Insert new index entry to block.
 873  *         Note that space for new entry must be checked by caller.
 874  * @param inode_ref   Directory i-node
 875  * @param index_block Block where to insert new entry
 876  * @param hash        Hash value covered by child node
 877  * @param iblock      Logical number of child block
 878  *
 879  */
 880 static void
 881 ext4_dir_dx_insert_entry(struct ext4_inode_ref *inode_ref __unused,
 882                          struct ext4_dir_idx_block *index_block,
 883                          uint32_t hash, uint32_t iblock)
 884 {
 885         struct ext4_dir_idx_entry *old_index_entry = index_block->position;
 886         struct ext4_dir_idx_entry *new_index_entry = old_index_entry + 1;
 887         struct ext4_dir_idx_climit *climit = (void *)index_block->entries;
 888         struct ext4_dir_idx_entry *start_index = index_block->entries;
 889         uint32_t count = ext4_dir_dx_climit_get_count(climit);
 890
 891         size_t bytes;
 892         bytes = (uint8_t *)(start_index + count) - (uint8_t *)(new_index_entry);
 893
 894         memmove(new_index_entry + 1, new_index_entry, bytes);
 895
 896         ext4_dir_dx_entry_set_block(new_index_entry, iblock);
 897         ext4_dir_dx_entry_set_hash(new_index_entry, hash);
 898         ext4_dir_dx_climit_set_count(climit, count + 1);
 899         ext4_dir_set_dx_csum(inode_ref, (void *)index_block->b.data);
 900         ext4_bcache_set_dirty(index_block->b.buf);
 901 }
 902
 903 /**@brief Split directory entries to two parts preventing node overflow.
 904  * @param inode_ref      Directory i-node
 905  * @param hinfo          Hash info
 906  * @param old_data_block Block with data to be split
 907  * @param index_block    Block where index entries are located
 908  * @param new_data_block Output value for newly allocated data block
 909  */
 910 static int ext4_dir_dx_split_data(struct ext4_inode_ref *inode_ref,
 911                                   struct ext4_hash_info *hinfo,
 912                                   struct ext4_block *old_data_block,
 913                                   struct ext4_dir_idx_block *index_block,
 914                                   struct ext4_block *new_data_block)
 915 {
 916         int rc = EOK;
 917         struct ext4_sblock *sb = &inode_ref->fs->sb;
 918         uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
 919
 920         /* Allocate buffer for directory entries */
 921         uint8_t *entry_buffer = malloc(block_size);
 922         if (entry_buffer == NULL)
 923                 return ENOMEM;
 924
 925         /* dot entry has the smallest size available */
 926         uint32_t max_ecnt = block_size / sizeof(struct ext4_dir_idx_dot_en);
 927
 928         /* Allocate sort entry */
 929         struct ext4_dx_sort_entry *sort;
 930
 931         sort = malloc(max_ecnt * sizeof(struct ext4_dx_sort_entry));
 932         if (sort == NULL) {
 933                 free(entry_buffer);
 934                 return ENOMEM;
 935         }
 936
 937         uint32_t idx = 0;
 938         uint32_t real_size = 0;
 939
 940         /* Initialize hinfo */
 941         struct ext4_hash_info hinfo_tmp;
 942         memcpy(&hinfo_tmp, hinfo, sizeof(struct ext4_hash_info));
 943
 944         /* Load all valid entries to the buffer */
 945         struct ext4_dir_en *de = (void *)old_data_block->data;
 946         uint8_t *entry_buffer_ptr = entry_buffer;
 947         while ((void *)de < (void *)(old_data_block->data + block_size)) {
 948                 /* Read only valid entries */
 949                 if (ext4_dir_en_get_inode(de) && de->name_len) {
 950                         uint8_t len = ext4_dir_en_get_name_len(sb, de);
 951                         rc = ext4_dir_dx_hash_string(&hinfo_tmp, len,
 952                                                      (char *)de->name);
 953                         if (rc != EOK) {
 954                                 free(sort);
 955                                 free(entry_buffer);
 956                                 return rc;
 957                         }
 958
 959                         uint32_t rec_len = 8 + len;
 960                         if ((rec_len % 4) != 0)
 961                                 rec_len += 4 - (rec_len % 4);
 962
 963                         memcpy(entry_buffer_ptr, de, rec_len);
 964
 965                         sort[idx].dentry = entry_buffer_ptr;
 966                         sort[idx].rec_len = rec_len;
 967                         sort[idx].hash = hinfo_tmp.hash;
 968
 969                         entry_buffer_ptr += rec_len;
 970                         real_size += rec_len;
 971                         idx++;
 972                 }
 973
 974                 size_t elen = ext4_dir_en_get_entry_len(de);
 975                 de = (void *)((uint8_t *)de + elen);
 976         }
 977
 978 /* Sort all entries */
 979 #if CONFIG_DIR_INDEX_COMB_SORT
 980         comb_sort(sort, idx);
 981 #else
 982         qsort(sort, idx, sizeof(struct ext4_dx_sort_entry),
 983               ext4_dir_dx_entry_comparator);
 984 #endif
 985         /* Allocate new block for store the second part of entries */
 986         ext4_fsblk_t new_fblock;
 987         uint32_t new_iblock;
 988         rc = ext4_fs_append_inode_dblk(inode_ref, &new_fblock, &new_iblock);
 989         if (rc != EOK) {
 990                 free(sort);
 991                 free(entry_buffer);
 992                 return rc;
 993         }
 994
 995         /* Load new block */
 996         struct ext4_block new_data_block_tmp;
 997         rc = ext4_block_get_noread(inode_ref->fs->bdev, &new_data_block_tmp,
 998                                    new_fblock);
 999         if (rc != EOK) {
1000                 free(sort);
1001                 free(entry_buffer);
1002                 return rc;
1003         }
1004
1005         /*
1006          * Distribute entries to two blocks (by size)
1007          * - compute the half
1008          */
1009         uint32_t new_hash = 0;
1010         uint32_t current_size = 0;
1011         uint32_t mid = 0;
1012         uint32_t i;
1013         for (i = 0; i < idx; ++i) {
1014                 if ((current_size + sort[i].rec_len) > (block_size / 2)) {
1015                         new_hash = sort[i].hash;
1016                         mid = i;
1017                         break;
1018                 }
1019
1020                 current_size += sort[i].rec_len;
1021         }
1022
1023         /* Check hash collision */
1024         uint32_t continued = 0;
1025         if (new_hash == sort[mid - 1].hash)
1026                 continued = 1;
1027
1028         uint32_t off = 0;
1029         void *ptr;
1030         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
1031                 block_size -= sizeof(struct ext4_dir_entry_tail);
1032
1033         /* First part - to the old block */
1034         for (i = 0; i < mid; ++i) {
1035                 ptr = old_data_block->data + off;
1036                 memcpy(ptr, sort[i].dentry, sort[i].rec_len);
1037
1038                 struct ext4_dir_en *t = ptr;
1039                 if (i < (mid - 1))
1040                         ext4_dir_en_set_entry_len(t, sort[i].rec_len);
1041                 else
1042                         ext4_dir_en_set_entry_len(t, block_size - off);
1043
1044                 off += sort[i].rec_len;
1045         }
1046
1047         /* Second part - to the new block */
1048         off = 0;
1049         for (i = mid; i < idx; ++i) {
1050                 ptr = new_data_block_tmp.data + off;
1051                 memcpy(ptr, sort[i].dentry, sort[i].rec_len);
1052
1053                 struct ext4_dir_en *t = ptr;
1054                 if (i < (idx - 1))
1055                         ext4_dir_en_set_entry_len(t, sort[i].rec_len);
1056                 else
1057                         ext4_dir_en_set_entry_len(t, block_size - off);
1058
1059                 off += sort[i].rec_len;
1060         }
1061
1062         block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
1063
1064         /* Do some steps to finish operation */
1065         sb = &inode_ref->fs->sb;
1066         if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
1067                 struct ext4_dir_entry_tail *t;
1068
1069                 t = EXT4_DIRENT_TAIL(old_data_block->data, block_size);
1070                 ext4_dir_init_entry_tail(t);
1071                 t = EXT4_DIRENT_TAIL(new_data_block_tmp.data, block_size);
1072                 ext4_dir_init_entry_tail(t);
1073         }
1074         ext4_dir_set_csum(inode_ref, (void *)old_data_block->data);
1075         ext4_dir_set_csum(inode_ref, (void *)new_data_block_tmp.data);
1076         ext4_bcache_set_dirty(old_data_block->buf);
1077         ext4_bcache_set_dirty(new_data_block_tmp.buf);
1078
1079         free(sort);
1080         free(entry_buffer);
1081
1082         ext4_dir_dx_insert_entry(inode_ref, index_block, new_hash + continued,
1083                                 new_iblock);
1084
1085         *new_data_block = new_data_block_tmp;
1086         return EOK;
1087 }
1088
1089 /**@brief  Split index node and maybe some parent nodes in the tree hierarchy.
1090  * @param inode_ref Directory i-node
1091  * @param dx_blocks Array with path from root to leaf node
1092  * @param dx_block  Leaf block to be split if needed
1093  * @return Error code
1094  */
1095 static int
1096 ext4_dir_dx_split_index(struct ext4_inode_ref *ino_ref,
1097                         struct ext4_dir_idx_block *dx_blks,
1098                         struct ext4_dir_idx_block *dxb,
1099                         struct ext4_dir_idx_block **new_dx_block)
1100 {
1101         struct ext4_sblock *sb = &ino_ref->fs->sb;
1102         struct ext4_dir_idx_entry *e;
1103         int r;
1104
1105         uint32_t block_size = ext4_sb_get_block_size(&ino_ref->fs->sb);
1106         uint32_t entry_space = block_size - sizeof(struct ext4_fake_dir_entry);
1107         uint32_t node_limit =  entry_space / sizeof(struct ext4_dir_idx_entry);
1108
1109         bool meta_csum = ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM);
1110
1111         if (dxb == dx_blks)
1112                 e = ((struct ext4_dir_idx_root *)dxb->b.data)->en;
1113         else
1114                 e = ((struct ext4_dir_idx_node *)dxb->b.data)->entries;
1115
1116         struct ext4_dir_idx_climit *climit = (struct ext4_dir_idx_climit *)e;
1117
1118         uint16_t leaf_limit = ext4_dir_dx_climit_get_limit(climit);
1119         uint16_t leaf_count = ext4_dir_dx_climit_get_count(climit);
1120
1121         /* Check if is necessary to split index block */
1122         if (leaf_limit == leaf_count) {
1123                 struct ext4_dir_idx_entry *ren;
1124                 ptrdiff_t levels = dxb - dx_blks;
1125
1126                 ren = ((struct ext4_dir_idx_root *)dx_blks[0].b.data)->en;
1127                 struct ext4_dir_idx_climit *rclimit = (void *)ren;
1128                 uint16_t root_limit = ext4_dir_dx_climit_get_limit(rclimit);
1129                 uint16_t root_count = ext4_dir_dx_climit_get_count(rclimit);
1130
1131
1132                 /* Linux limitation */
1133                 if ((levels > 0) && (root_limit == root_count))
1134                         return ENOSPC;
1135
1136                 /* Add new block to directory */
1137                 ext4_fsblk_t new_fblk;
1138                 uint32_t new_iblk;
1139                 r = ext4_fs_append_inode_dblk(ino_ref, &new_fblk, &new_iblk);
1140                 if (r != EOK)
1141                         return r;
1142
1143                 /* load new block */
1144                 struct ext4_block b;
1145                 r = ext4_block_get_noread(ino_ref->fs->bdev, &b, new_fblk);
1146                 if (r != EOK)
1147                         return r;
1148
1149                 struct ext4_dir_idx_node *new_node = (void *)b.data;
1150                 struct ext4_dir_idx_entry *new_en = new_node->entries;
1151
1152                 memset(&new_node->fake, 0, sizeof(struct ext4_fake_dir_entry));
1153                 new_node->fake.entry_length = block_size;
1154
1155                 /* Split leaf node */
1156                 if (levels > 0) {
1157                         uint32_t count_left = leaf_count / 2;
1158                         uint32_t count_right = leaf_count - count_left;
1159                         uint32_t hash_right;
1160                         size_t sz;
1161
1162                         struct ext4_dir_idx_climit *left_climit;
1163                         struct ext4_dir_idx_climit *right_climit;
1164
1165                         hash_right = ext4_dir_dx_entry_get_hash(e + count_left);
1166                         /* Copy data to new node */
1167                         sz = count_right * sizeof(struct ext4_dir_idx_entry);
1168                         memcpy(new_en, e + count_left, sz);
1169
1170                         /* Initialize new node */
1171                         left_climit = (struct ext4_dir_idx_climit *)e;
1172                         right_climit = (struct ext4_dir_idx_climit *)new_en;
1173
1174                         ext4_dir_dx_climit_set_count(left_climit, count_left);
1175                         ext4_dir_dx_climit_set_count(right_climit, count_right);
1176
1177                         if (meta_csum)
1178                                 entry_space -= sizeof(struct ext4_dir_idx_tail);
1179
1180                         ext4_dir_dx_climit_set_limit(right_climit, node_limit);
1181
1182                         /* Which index block is target for new entry */
1183                         uint32_t position_index =
1184                             (dxb->position - dxb->entries);
1185                         if (position_index >= count_left) {
1186                                 ext4_dir_set_dx_csum(
1187                                                 ino_ref,
1188                                                 (struct ext4_dir_en *)
1189                                                 dxb->b.data);
1190                                 ext4_bcache_set_dirty(dxb->b.buf);
1191
1192                                 struct ext4_block block_tmp = dxb->b;
1193
1194                                 dxb->b = b;
1195
1196                                 dxb->position =
1197                                     new_en + position_index - count_left;
1198                                 dxb->entries = new_en;
1199
1200                                 b = block_tmp;
1201                         }
1202
1203                         /* Finally insert new entry */
1204                         ext4_dir_dx_insert_entry(ino_ref, dx_blks, hash_right,
1205                                                  new_iblk);
1206                         ext4_dir_set_dx_csum(ino_ref, (void*)dx_blks[0].b.data);
1207                         ext4_dir_set_dx_csum(ino_ref, (void*)dx_blks[1].b.data);
1208                         ext4_bcache_set_dirty(dx_blks[0].b.buf);
1209                         ext4_bcache_set_dirty(dx_blks[1].b.buf);
1210
1211                         ext4_dir_set_dx_csum(ino_ref, (void *)b.data);
1212                         ext4_bcache_set_dirty(b.buf);
1213                         return ext4_block_set(ino_ref->fs->bdev, &b);
1214                 } else {
1215                         size_t sz;
1216                         /* Copy data from root to child block */
1217                         sz = leaf_count * sizeof(struct ext4_dir_idx_entry);
1218                         memcpy(new_en, e, sz);
1219
1220                         struct ext4_dir_idx_climit *new_climit = (void*)new_en;
1221                         if (meta_csum)
1222                                 entry_space -= sizeof(struct ext4_dir_idx_tail);
1223
1224                         ext4_dir_dx_climit_set_limit(new_climit, node_limit);
1225
1226                         /* Set values in root node */
1227                         struct ext4_dir_idx_climit *new_root_climit = (void *)e;
1228
1229                         ext4_dir_dx_climit_set_count(new_root_climit, 1);
1230                         ext4_dir_dx_entry_set_block(e, new_iblk);
1231
1232                         struct ext4_dir_idx_root *r = (void *)dx_blks[0].b.data;
1233                         r->info.indirect_levels = 1;
1234
1235                         /* Add new entry to the path */
1236                         dxb = dx_blks + 1;
1237                         dxb->position = dx_blks->position - e + new_en;
1238                         dxb->entries = new_en;
1239                         dxb->b = b;
1240                         *new_dx_block = dxb;
1241
1242                         ext4_dir_set_dx_csum(ino_ref, (void*)dx_blks[0].b.data);
1243                         ext4_dir_set_dx_csum(ino_ref, (void*)dx_blks[1].b.data);
1244                         ext4_bcache_set_dirty(dx_blks[0].b.buf);
1245                         ext4_bcache_set_dirty(dx_blks[1].b.buf);
1246                 }
1247         }
1248
1249         return EOK;
1250 }
1251
1252 int ext4_dir_dx_add_entry(struct ext4_inode_ref *parent,
1253                           struct ext4_inode_ref *child, const char *name)
1254 {
1255         int rc2 = EOK;
1256         int r;
1257         /* Get direct block 0 (index root) */
1258         ext4_fsblk_t rblock_addr;
1259         r =  ext4_fs_get_inode_dblk_idx(parent, 0, &rblock_addr, false);
1260         if (r != EOK)
1261                 return r;
1262
1263         struct ext4_fs *fs = parent->fs;
1264         struct ext4_block root_blk;
1265
1266         r = ext4_block_get(fs->bdev, &root_blk, rblock_addr);
1267         if (r != EOK)
1268                 return r;
1269
1270         if (!ext4_dir_dx_csum_verify(parent, (void*)root_blk.data)) {
1271                 ext4_dbg(DEBUG_DIR_IDX,
1272                          DBG_WARN "HTree root checksum failed."
1273                          "Inode: %" PRIu32", "
1274                          "Block: %" PRIu32"\n",
1275                          parent->index,
1276                          (uint32_t)0);
1277         }
1278
1279         /* Initialize hinfo structure (mainly compute hash) */
1280         uint32_t name_len = strlen(name);
1281         struct ext4_hash_info hinfo;
1282         r = ext4_dir_hinfo_init(&hinfo, &root_blk, &fs->sb, name_len, name);
1283         if (r != EOK) {
1284                 ext4_block_set(fs->bdev, &root_blk);
1285                 return EXT4_ERR_BAD_DX_DIR;
1286         }
1287
1288         /*
1289          * Hardcoded number 2 means maximum height of index
1290          * tree defined in Linux.
1291          */
1292         struct ext4_dir_idx_block dx_blks[2];
1293         struct ext4_dir_idx_block *dx_blk;
1294         struct ext4_dir_idx_block *dx_it;
1295
1296         r = ext4_dir_dx_get_leaf(&hinfo, parent, &root_blk, &dx_blk, dx_blks);
1297         if (r != EOK) {
1298                 r = 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 = ext4_dir_dx_entry_get_block(dx_blk->position);
1304         ext4_fsblk_t leaf_block_addr;
1305         r = ext4_fs_get_inode_dblk_idx(parent, leaf_block_idx,
1306                                                 &leaf_block_addr, false);
1307         if (r != EOK)
1308                 goto release_index;
1309
1310         /*
1311          * Check if there is needed to split index node
1312          * (and recursively also parent nodes)
1313          */
1314         r = ext4_dir_dx_split_index(parent, dx_blks, dx_blk, &dx_blk);
1315         if (r != EOK)
1316                 goto release_target_index;
1317
1318         struct ext4_block target_block;
1319         r = ext4_block_get(fs->bdev, &target_block, leaf_block_addr);
1320         if (r != EOK)
1321                 goto release_index;
1322
1323         if (!ext4_dir_csum_verify(parent,(void *)target_block.data)) {
1324                 ext4_dbg(DEBUG_DIR_IDX,
1325                                 DBG_WARN "HTree leaf block checksum failed."
1326                                 "Inode: %" PRIu32", "
1327                                 "Block: %" PRIu32"\n",
1328                                 parent->index,
1329                                 leaf_block_idx);
1330         }
1331
1332         /* Check if insert operation passed */
1333         r = ext4_dir_try_insert_entry(&fs->sb, parent, &target_block, child,
1334                                         name, name_len);
1335         if (r == EOK)
1336                 goto release_target_index;
1337
1338         /* Split entries to two blocks (includes sorting by hash value) */
1339         struct ext4_block new_block;
1340         r = ext4_dir_dx_split_data(parent, &hinfo, &target_block, dx_blk,
1341                                     &new_block);
1342         if (r != EOK) {
1343                 rc2 = r;
1344                 goto release_target_index;
1345         }
1346
1347         /* Where to save new entry */
1348         uint32_t blk_hash = ext4_dir_dx_entry_get_hash(dx_blk->position + 1);
1349         if (hinfo.hash >= blk_hash)
1350                 r = ext4_dir_try_insert_entry(&fs->sb, parent, &new_block,
1351                                                 child, name, name_len);
1352         else
1353                 r = ext4_dir_try_insert_entry(&fs->sb, parent, &target_block,
1354                                                 child, name, name_len);
1355
1356         /* Cleanup */
1357         r = ext4_block_set(fs->bdev, &new_block);
1358         if (r != EOK)
1359                 return r;
1360
1361 /* Cleanup operations */
1362
1363 release_target_index:
1364         rc2 = r;
1365
1366         r = ext4_block_set(fs->bdev, &target_block);
1367         if (r != EOK)
1368                 return r;
1369
1370 release_index:
1371         if (r != EOK)
1372                 rc2 = r;
1373
1374         dx_it = dx_blks;
1375
1376         while (dx_it <= dx_blk) {
1377                 r = ext4_block_set(fs->bdev, &dx_it->b);
1378                 if (r != EOK)
1379                         return r;
1380
1381                 dx_it++;
1382         }
1383
1384         return rc2;
1385 }
1386
1387 int ext4_dir_dx_reset_parent_inode(struct ext4_inode_ref *dir,
1388                                    uint32_t parent_inode)
1389 {
1390         /* Load block 0, where will be index root located */
1391         ext4_fsblk_t fblock;
1392         int rc = ext4_fs_get_inode_dblk_idx(dir, 0, &fblock, false);
1393         if (rc != EOK)
1394                 return rc;
1395
1396         struct ext4_block block;
1397         rc = ext4_block_get(dir->fs->bdev, &block, fblock);
1398         if (rc != EOK)
1399                 return rc;
1400
1401         if (!ext4_dir_dx_csum_verify(dir, (void *)block.data)) {
1402                 ext4_dbg(DEBUG_DIR_IDX,
1403                          DBG_WARN "HTree root checksum failed."
1404                          "Inode: %" PRIu32", "
1405                          "Block: %" PRIu32"\n",
1406                          dir->index,
1407                          (uint32_t)0);
1408         }
1409
1410         /* Initialize pointers to data structures */
1411         struct ext4_dir_idx_root *root = (void *)block.data;
1412
1413         /* Fill the inode field with a new parent ino. */
1414         ext4_dx_dot_en_set_inode(&root->dots[1], parent_inode);
1415
1416         ext4_dir_set_dx_csum(dir, (void *)block.data);
1417         ext4_bcache_set_dirty(block.buf);
1418
1419         return ext4_block_set(dir->fs->bdev, &block);
1420 }
1421
1422 /**
1423  * @}
1424  */