fs/ext4/ext4_common.c

   1 /*
   2  * (C) Copyright 2011 - 2012 Samsung Electronics
   3  * EXT4 filesystem implementation in Uboot by
   4  * Uma Shankar <uma.shankar@samsung.com>
   5  * Manjunatha C Achar <a.manjunatha@samsung.com>
   6  *
   7  * ext4ls and ext4load : Based on ext2 ls load support in Uboot.
   8  *
   9  * (C) Copyright 2004
  10  * esd gmbh <www.esd-electronics.com>
  11  * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
  12  *
  13  * based on code from grub2 fs/ext2.c and fs/fshelp.c by
  14  * GRUB  --  GRand Unified Bootloader
  15  * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
  16  *
  17  * ext4write : Based on generic ext4 protocol.
  18  *
  19  * SPDX-License-Identifier:     GPL-2.0+
  20  */
  21
  22 #include <common.h>
  23 #include <ext_common.h>
  24 #include <ext4fs.h>
  25 #include <inttypes.h>
  26 #include <malloc.h>
  27 #include <memalign.h>
  28 #include <stddef.h>
  29 #include <linux/stat.h>
  30 #include <linux/time.h>
  31 #include <asm/byteorder.h>
  32 #include "ext4_common.h"
  33
  34 struct ext2_data *ext4fs_root;
  35 struct ext2fs_node *ext4fs_file;
  36 __le32 *ext4fs_indir1_block;
  37 int ext4fs_indir1_size;
  38 int ext4fs_indir1_blkno = -1;
  39 __le32 *ext4fs_indir2_block;
  40 int ext4fs_indir2_size;
  41 int ext4fs_indir2_blkno = -1;
  42
  43 __le32 *ext4fs_indir3_block;
  44 int ext4fs_indir3_size;
  45 int ext4fs_indir3_blkno = -1;
  46 struct ext2_inode *g_parent_inode;
  47 static int symlinknest;
  48
  49 #if defined(CONFIG_EXT4_WRITE)
  50 static inline void ext4fs_sb_free_inodes_dec(struct ext2_sblock *sb)
  51 {
  52         sb->free_inodes = cpu_to_le32(le32_to_cpu(sb->free_inodes) - 1);
  53 }
  54
  55 static inline void ext4fs_sb_free_blocks_dec(struct ext2_sblock *sb)
  56 {
  57         sb->free_blocks = cpu_to_le32(le32_to_cpu(sb->free_blocks) - 1);
  58 }
  59
  60 static inline void ext4fs_bg_free_inodes_dec(struct ext2_block_group *bg)
  61 {
  62         bg->free_inodes = cpu_to_le16(le16_to_cpu(bg->free_inodes) - 1);
  63 }
  64
  65 static inline void ext4fs_bg_free_blocks_dec(struct ext2_block_group *bg)
  66 {
  67         bg->free_blocks = cpu_to_le16(le16_to_cpu(bg->free_blocks) - 1);
  68 }
  69
  70 static inline void ext4fs_bg_itable_unused_dec(struct ext2_block_group *bg)
  71 {
  72         bg->bg_itable_unused = cpu_to_le16(le16_to_cpu(bg->bg_itable_unused) - 1);
  73 }
  74
  75 uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n)
  76 {
  77         uint32_t res = size / n;
  78         if (res * n != size)
  79                 res++;
  80
  81         return res;
  82 }
  83
  84 void put_ext4(uint64_t off, void *buf, uint32_t size)
  85 {
  86         uint64_t startblock;
  87         uint64_t remainder;
  88         unsigned char *temp_ptr = NULL;
  89         struct ext_filesystem *fs = get_fs();
  90         int log2blksz = fs->dev_desc->log2blksz;
  91         ALLOC_CACHE_ALIGN_BUFFER(unsigned char, sec_buf, fs->dev_desc->blksz);
  92
  93         startblock = off >> log2blksz;
  94         startblock += part_offset;
  95         remainder = off & (uint64_t)(fs->dev_desc->blksz - 1);
  96
  97         if (fs->dev_desc == NULL)
  98                 return;
  99
 100         if ((startblock + (size >> log2blksz)) >
 101             (part_offset + fs->total_sect)) {
 102                 printf("part_offset is " LBAFU "\n", part_offset);
 103                 printf("total_sector is %" PRIu64 "\n", fs->total_sect);
 104                 printf("error: overflow occurs\n");
 105                 return;
 106         }
 107
 108         if (remainder) {
 109                 blk_dread(fs->dev_desc, startblock, 1, sec_buf);
 110                 temp_ptr = sec_buf;
 111                 memcpy((temp_ptr + remainder), (unsigned char *)buf, size);
 112                 blk_dwrite(fs->dev_desc, startblock, 1, sec_buf);
 113         } else {
 114                 if (size >> log2blksz != 0) {
 115                         blk_dwrite(fs->dev_desc, startblock, size >> log2blksz,
 116                                    (unsigned long *)buf);
 117                 } else {
 118                         blk_dread(fs->dev_desc, startblock, 1, sec_buf);
 119                         temp_ptr = sec_buf;
 120                         memcpy(temp_ptr, buf, size);
 121                         blk_dwrite(fs->dev_desc, startblock, 1,
 122                                    (unsigned long *)sec_buf);
 123                 }
 124         }
 125 }
 126
 127 static int _get_new_inode_no(unsigned char *buffer)
 128 {
 129         struct ext_filesystem *fs = get_fs();
 130         unsigned char input;
 131         int operand, status;
 132         int count = 1;
 133         int j = 0;
 134
 135         /* get the blocksize of the filesystem */
 136         unsigned char *ptr = buffer;
 137         while (*ptr == 255) {
 138                 ptr++;
 139                 count += 8;
 140                 if (count > le32_to_cpu(ext4fs_root->sblock.inodes_per_group))
 141                         return -1;
 142         }
 143
 144         for (j = 0; j < fs->blksz; j++) {
 145                 input = *ptr;
 146                 int i = 0;
 147                 while (i <= 7) {
 148                         operand = 1 << i;
 149                         status = input & operand;
 150                         if (status) {
 151                                 i++;
 152                                 count++;
 153                         } else {
 154                                 *ptr |= operand;
 155                                 return count;
 156                         }
 157                 }
 158                 ptr = ptr + 1;
 159         }
 160
 161         return -1;
 162 }
 163
 164 static int _get_new_blk_no(unsigned char *buffer)
 165 {
 166         unsigned char input;
 167         int operand, status;
 168         int count = 0;
 169         int j = 0;
 170         unsigned char *ptr = buffer;
 171         struct ext_filesystem *fs = get_fs();
 172
 173         if (fs->blksz != 1024)
 174                 count = 0;
 175         else
 176                 count = 1;
 177
 178         while (*ptr == 255) {
 179                 ptr++;
 180                 count += 8;
 181                 if (count == (fs->blksz * 8))
 182                         return -1;
 183         }
 184
 185         for (j = 0; j < fs->blksz; j++) {
 186                 input = *ptr;
 187                 int i = 0;
 188                 while (i <= 7) {
 189                         operand = 1 << i;
 190                         status = input & operand;
 191                         if (status) {
 192                                 i++;
 193                                 count++;
 194                         } else {
 195                                 *ptr |= operand;
 196                                 return count;
 197                         }
 198                 }
 199                 ptr = ptr + 1;
 200         }
 201
 202         return -1;
 203 }
 204
 205 int ext4fs_set_block_bmap(long int blockno, unsigned char *buffer, int index)
 206 {
 207         int i, remainder, status;
 208         unsigned char *ptr = buffer;
 209         unsigned char operand;
 210         i = blockno / 8;
 211         remainder = blockno % 8;
 212         int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
 213
 214         i = i - (index * blocksize);
 215         if (blocksize != 1024) {
 216                 ptr = ptr + i;
 217                 operand = 1 << remainder;
 218                 status = *ptr & operand;
 219                 if (status)
 220                         return -1;
 221
 222                 *ptr = *ptr | operand;
 223                 return 0;
 224         } else {
 225                 if (remainder == 0) {
 226                         ptr = ptr + i - 1;
 227                         operand = (1 << 7);
 228                 } else {
 229                         ptr = ptr + i;
 230                         operand = (1 << (remainder - 1));
 231                 }
 232                 status = *ptr & operand;
 233                 if (status)
 234                         return -1;
 235
 236                 *ptr = *ptr | operand;
 237                 return 0;
 238         }
 239 }
 240
 241 void ext4fs_reset_block_bmap(long int blockno, unsigned char *buffer, int index)
 242 {
 243         int i, remainder, status;
 244         unsigned char *ptr = buffer;
 245         unsigned char operand;
 246         i = blockno / 8;
 247         remainder = blockno % 8;
 248         int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
 249
 250         i = i - (index * blocksize);
 251         if (blocksize != 1024) {
 252                 ptr = ptr + i;
 253                 operand = (1 << remainder);
 254                 status = *ptr & operand;
 255                 if (status)
 256                         *ptr = *ptr & ~(operand);
 257         } else {
 258                 if (remainder == 0) {
 259                         ptr = ptr + i - 1;
 260                         operand = (1 << 7);
 261                 } else {
 262                         ptr = ptr + i;
 263                         operand = (1 << (remainder - 1));
 264                 }
 265                 status = *ptr & operand;
 266                 if (status)
 267                         *ptr = *ptr & ~(operand);
 268         }
 269 }
 270
 271 int ext4fs_set_inode_bmap(int inode_no, unsigned char *buffer, int index)
 272 {
 273         int i, remainder, status;
 274         unsigned char *ptr = buffer;
 275         unsigned char operand;
 276
 277         inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
 278         i = inode_no / 8;
 279         remainder = inode_no % 8;
 280         if (remainder == 0) {
 281                 ptr = ptr + i - 1;
 282                 operand = (1 << 7);
 283         } else {
 284                 ptr = ptr + i;
 285                 operand = (1 << (remainder - 1));
 286         }
 287         status = *ptr & operand;
 288         if (status)
 289                 return -1;
 290
 291         *ptr = *ptr | operand;
 292
 293         return 0;
 294 }
 295
 296 void ext4fs_reset_inode_bmap(int inode_no, unsigned char *buffer, int index)
 297 {
 298         int i, remainder, status;
 299         unsigned char *ptr = buffer;
 300         unsigned char operand;
 301
 302         inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
 303         i = inode_no / 8;
 304         remainder = inode_no % 8;
 305         if (remainder == 0) {
 306                 ptr = ptr + i - 1;
 307                 operand = (1 << 7);
 308         } else {
 309                 ptr = ptr + i;
 310                 operand = (1 << (remainder - 1));
 311         }
 312         status = *ptr & operand;
 313         if (status)
 314                 *ptr = *ptr & ~(operand);
 315 }
 316
 317 uint16_t ext4fs_checksum_update(uint32_t i)
 318 {
 319         struct ext2_block_group *desc;
 320         struct ext_filesystem *fs = get_fs();
 321         uint16_t crc = 0;
 322         __le32 le32_i = cpu_to_le32(i);
 323
 324         desc = (struct ext2_block_group *)&fs->bgd[i];
 325         if (le32_to_cpu(fs->sb->feature_ro_compat) & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
 326                 int offset = offsetof(struct ext2_block_group, bg_checksum);
 327
 328                 crc = ext2fs_crc16(~0, fs->sb->unique_id,
 329                                    sizeof(fs->sb->unique_id));
 330                 crc = ext2fs_crc16(crc, &le32_i, sizeof(le32_i));
 331                 crc = ext2fs_crc16(crc, desc, offset);
 332                 offset += sizeof(desc->bg_checksum);    /* skip checksum */
 333                 assert(offset == sizeof(*desc));
 334         }
 335
 336         return crc;
 337 }
 338
 339 static int check_void_in_dentry(struct ext2_dirent *dir, char *filename)
 340 {
 341         int dentry_length;
 342         int sizeof_void_space;
 343         int new_entry_byte_reqd;
 344         short padding_factor = 0;
 345
 346         if (dir->namelen % 4 != 0)
 347                 padding_factor = 4 - (dir->namelen % 4);
 348
 349         dentry_length = sizeof(struct ext2_dirent) +
 350                         dir->namelen + padding_factor;
 351         sizeof_void_space = le16_to_cpu(dir->direntlen) - dentry_length;
 352         if (sizeof_void_space == 0)
 353                 return 0;
 354
 355         padding_factor = 0;
 356         if (strlen(filename) % 4 != 0)
 357                 padding_factor = 4 - (strlen(filename) % 4);
 358
 359         new_entry_byte_reqd = strlen(filename) +
 360             sizeof(struct ext2_dirent) + padding_factor;
 361         if (sizeof_void_space >= new_entry_byte_reqd) {
 362                 dir->direntlen = cpu_to_le16(dentry_length);
 363                 return sizeof_void_space;
 364         }
 365
 366         return 0;
 367 }
 368
 369 int ext4fs_update_parent_dentry(char *filename, int file_type)
 370 {
 371         unsigned int *zero_buffer = NULL;
 372         char *root_first_block_buffer = NULL;
 373         int blk_idx;
 374         long int first_block_no_of_root = 0;
 375         int totalbytes = 0;
 376         unsigned int new_entry_byte_reqd;
 377         int sizeof_void_space = 0;
 378         int templength = 0;
 379         int inodeno = -1;
 380         int status;
 381         struct ext_filesystem *fs = get_fs();
 382         /* directory entry */
 383         struct ext2_dirent *dir;
 384         char *temp_dir = NULL;
 385         uint32_t new_blk_no;
 386         uint32_t new_size;
 387         uint32_t new_blockcnt;
 388         uint32_t directory_blocks;
 389
 390         zero_buffer = zalloc(fs->blksz);
 391         if (!zero_buffer) {
 392                 printf("No Memory\n");
 393                 return -1;
 394         }
 395         root_first_block_buffer = zalloc(fs->blksz);
 396         if (!root_first_block_buffer) {
 397                 free(zero_buffer);
 398                 printf("No Memory\n");
 399                 return -1;
 400         }
 401         new_entry_byte_reqd = ROUND(strlen(filename) +
 402                                     sizeof(struct ext2_dirent), 4);
 403 restart:
 404         directory_blocks = le32_to_cpu(g_parent_inode->size) >>
 405                 LOG2_BLOCK_SIZE(ext4fs_root);
 406         blk_idx = directory_blocks - 1;
 407
 408 restart_read:
 409         /* read the block no allocated to a file */
 410         first_block_no_of_root = read_allocated_block(g_parent_inode, blk_idx);
 411         if (first_block_no_of_root <= 0)
 412                 goto fail;
 413
 414         status = ext4fs_devread((lbaint_t)first_block_no_of_root
 415                                 * fs->sect_perblk,
 416                                 0, fs->blksz, root_first_block_buffer);
 417         if (status == 0)
 418                 goto fail;
 419
 420         if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root))
 421                 goto fail;
 422         dir = (struct ext2_dirent *)root_first_block_buffer;
 423         totalbytes = 0;
 424
 425         while (le16_to_cpu(dir->direntlen) > 0) {
 426                 unsigned short used_len = ROUND(dir->namelen +
 427                     sizeof(struct ext2_dirent), 4);
 428
 429                 /* last entry of block */
 430                 if (fs->blksz - totalbytes == le16_to_cpu(dir->direntlen)) {
 431
 432                         /* check if new entry fits */
 433                         if ((used_len + new_entry_byte_reqd) <=
 434                             le16_to_cpu(dir->direntlen)) {
 435                                 dir->direntlen = cpu_to_le16(used_len);
 436                                 break;
 437                         } else {
 438                                 if (blk_idx > 0) {
 439                                         printf("Block full, trying previous\n");
 440                                         blk_idx--;
 441                                         goto restart_read;
 442                                 }
 443                                 printf("All blocks full: Allocate new\n");
 444
 445                                 if (le32_to_cpu(g_parent_inode->flags) &
 446                                                 EXT4_EXTENTS_FL) {
 447                                         printf("Directory uses extents\n");
 448                                         goto fail;
 449                                 }
 450                                 if (directory_blocks >= INDIRECT_BLOCKS) {
 451                                         printf("Directory exceeds limit\n");
 452                                         goto fail;
 453                                 }
 454                                 new_blk_no = ext4fs_get_new_blk_no();
 455                                 if (new_blk_no == -1) {
 456                                         printf("no block left to assign\n");
 457                                         goto fail;
 458                                 }
 459                                 put_ext4((uint64_t)new_blk_no * fs->blksz, zero_buffer, fs->blksz);
 460                                 g_parent_inode->b.blocks.
 461                                         dir_blocks[directory_blocks] =
 462                                         cpu_to_le32(new_blk_no);
 463
 464                                 new_size = le32_to_cpu(g_parent_inode->size);
 465                                 new_size += fs->blksz;
 466                                 g_parent_inode->size = cpu_to_le32(new_size);
 467
 468                                 new_blockcnt = le32_to_cpu(g_parent_inode->blockcnt);
 469                                 new_blockcnt += fs->sect_perblk;
 470                                 g_parent_inode->blockcnt = cpu_to_le32(new_blockcnt);
 471
 472                                 if (ext4fs_put_metadata
 473                                     (root_first_block_buffer,
 474                                      first_block_no_of_root))
 475                                         goto fail;
 476                                 goto restart;
 477                         }
 478                 }
 479
 480                 templength = le16_to_cpu(dir->direntlen);
 481                 totalbytes = totalbytes + templength;
 482                 sizeof_void_space = check_void_in_dentry(dir, filename);
 483                 if (sizeof_void_space)
 484                         break;
 485
 486                 dir = (struct ext2_dirent *)((char *)dir + templength);
 487         }
 488
 489         /* make a pointer ready for creating next directory entry */
 490         templength = le16_to_cpu(dir->direntlen);
 491         totalbytes = totalbytes + templength;
 492         dir = (struct ext2_dirent *)((char *)dir + templength);
 493
 494         /* get the next available inode number */
 495         inodeno = ext4fs_get_new_inode_no();
 496         if (inodeno == -1) {
 497                 printf("no inode left to assign\n");
 498                 goto fail;
 499         }
 500         dir->inode = cpu_to_le32(inodeno);
 501         if (sizeof_void_space)
 502                 dir->direntlen = cpu_to_le16(sizeof_void_space);
 503         else
 504                 dir->direntlen = cpu_to_le16(fs->blksz - totalbytes);
 505
 506         dir->namelen = strlen(filename);
 507         dir->filetype = FILETYPE_REG;   /* regular file */
 508         temp_dir = (char *)dir;
 509         temp_dir = temp_dir + sizeof(struct ext2_dirent);
 510         memcpy(temp_dir, filename, strlen(filename));
 511
 512         /* update or write  the 1st block of root inode */
 513         if (ext4fs_put_metadata(root_first_block_buffer,
 514                                 first_block_no_of_root))
 515                 goto fail;
 516
 517 fail:
 518         free(zero_buffer);
 519         free(root_first_block_buffer);
 520
 521         return inodeno;
 522 }
 523
 524 static int search_dir(struct ext2_inode *parent_inode, char *dirname)
 525 {
 526         int status;
 527         int inodeno = 0;
 528         int offset;
 529         int blk_idx;
 530         long int blknr;
 531         char *block_buffer = NULL;
 532         struct ext2_dirent *dir = NULL;
 533         struct ext_filesystem *fs = get_fs();
 534         uint32_t directory_blocks;
 535         char *direntname;
 536
 537         directory_blocks = le32_to_cpu(parent_inode->size) >>
 538                 LOG2_BLOCK_SIZE(ext4fs_root);
 539
 540         block_buffer = zalloc(fs->blksz);
 541         if (!block_buffer)
 542                 goto fail;
 543
 544         /* get the block no allocated to a file */
 545         for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
 546                 blknr = read_allocated_block(parent_inode, blk_idx);
 547                 if (blknr == 0)
 548                         goto fail;
 549
 550                 /* read the directory block */
 551                 status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk,
 552                                         0, fs->blksz, (char *)block_buffer);
 553                 if (status == 0)
 554                         goto fail;
 555
 556                 offset = 0;
 557                 do {
 558                         dir = (struct ext2_dirent *)(block_buffer + offset);
 559                         direntname = (char*)(dir) + sizeof(struct ext2_dirent);
 560
 561                         int direntlen = le16_to_cpu(dir->direntlen);
 562                         if (direntlen < sizeof(struct ext2_dirent))
 563                                 break;
 564
 565                         if (dir->inode && (strlen(dirname) == dir->namelen) &&
 566                             (strncmp(dirname, direntname, dir->namelen) == 0)) {
 567                                 inodeno = le32_to_cpu(dir->inode);
 568                                 break;
 569                         }
 570
 571                         offset += direntlen;
 572
 573                 } while (offset < fs->blksz);
 574
 575                 if (inodeno > 0) {
 576                         free(block_buffer);
 577                         return inodeno;
 578                 }
 579         }
 580
 581 fail:
 582         free(block_buffer);
 583
 584         return -1;
 585 }
 586
 587 static int find_dir_depth(char *dirname)
 588 {
 589         char *token = strtok(dirname, "/");
 590         int count = 0;
 591         while (token != NULL) {
 592                 token = strtok(NULL, "/");
 593                 count++;
 594         }
 595         return count + 1 + 1;
 596         /*
 597          * for example  for string /home/temp
 598          * depth=home(1)+temp(1)+1 extra for NULL;
 599          * so count is 4;
 600          */
 601 }
 602
 603 static int parse_path(char **arr, char *dirname)
 604 {
 605         char *token = strtok(dirname, "/");
 606         int i = 0;
 607
 608         /* add root */
 609         arr[i] = zalloc(strlen("/") + 1);
 610         if (!arr[i])
 611                 return -ENOMEM;
 612         memcpy(arr[i++], "/", strlen("/"));
 613
 614         /* add each path entry after root */
 615         while (token != NULL) {
 616                 arr[i] = zalloc(strlen(token) + 1);
 617                 if (!arr[i])
 618                         return -ENOMEM;
 619                 memcpy(arr[i++], token, strlen(token));
 620                 token = strtok(NULL, "/");
 621         }
 622         arr[i] = NULL;
 623
 624         return 0;
 625 }
 626
 627 int ext4fs_iget(int inode_no, struct ext2_inode *inode)
 628 {
 629         if (ext4fs_read_inode(ext4fs_root, inode_no, inode) == 0)
 630                 return -1;
 631
 632         return 0;
 633 }
 634
 635 /*
 636  * Function: ext4fs_get_parent_inode_num
 637  * Return Value: inode Number of the parent directory of  file/Directory to be
 638  * created
 639  * dirname : Input parmater, input path name of the file/directory to be created
 640  * dname : Output parameter, to be filled with the name of the directory
 641  * extracted from dirname
 642  */
 643 int ext4fs_get_parent_inode_num(const char *dirname, char *dname, int flags)
 644 {
 645         int i;
 646         int depth = 0;
 647         int matched_inode_no;
 648         int result_inode_no = -1;
 649         char **ptr = NULL;
 650         char *depth_dirname = NULL;
 651         char *parse_dirname = NULL;
 652         struct ext2_inode *parent_inode = NULL;
 653         struct ext2_inode *first_inode = NULL;
 654         struct ext2_inode temp_inode;
 655
 656         if (*dirname != '/') {
 657                 printf("Please supply Absolute path\n");
 658                 return -1;
 659         }
 660
 661         /* TODO: input validation make equivalent to linux */
 662         depth_dirname = zalloc(strlen(dirname) + 1);
 663         if (!depth_dirname)
 664                 return -ENOMEM;
 665
 666         memcpy(depth_dirname, dirname, strlen(dirname));
 667         depth = find_dir_depth(depth_dirname);
 668         parse_dirname = zalloc(strlen(dirname) + 1);
 669         if (!parse_dirname)
 670                 goto fail;
 671         memcpy(parse_dirname, dirname, strlen(dirname));
 672
 673         /* allocate memory for each directory level */
 674         ptr = zalloc((depth) * sizeof(char *));
 675         if (!ptr)
 676                 goto fail;
 677         if (parse_path(ptr, parse_dirname))
 678                 goto fail;
 679         parent_inode = zalloc(sizeof(struct ext2_inode));
 680         if (!parent_inode)
 681                 goto fail;
 682         first_inode = zalloc(sizeof(struct ext2_inode));
 683         if (!first_inode)
 684                 goto fail;
 685         memcpy(parent_inode, ext4fs_root->inode, sizeof(struct ext2_inode));
 686         memcpy(first_inode, parent_inode, sizeof(struct ext2_inode));
 687         if (flags & F_FILE)
 688                 result_inode_no = EXT2_ROOT_INO;
 689         for (i = 1; i < depth; i++) {
 690                 matched_inode_no = search_dir(parent_inode, ptr[i]);
 691                 if (matched_inode_no == -1) {
 692                         if (ptr[i + 1] == NULL && i == 1) {
 693                                 result_inode_no = EXT2_ROOT_INO;
 694                                 goto end;
 695                         } else {
 696                                 if (ptr[i + 1] == NULL)
 697                                         break;
 698                                 printf("Invalid path\n");
 699                                 result_inode_no = -1;
 700                                 goto fail;
 701                         }
 702                 } else {
 703                         if (ptr[i + 1] != NULL) {
 704                                 memset(parent_inode, '\0',
 705                                        sizeof(struct ext2_inode));
 706                                 if (ext4fs_iget(matched_inode_no,
 707                                                 parent_inode)) {
 708                                         result_inode_no = -1;
 709                                         goto fail;
 710                                 }
 711                                 result_inode_no = matched_inode_no;
 712                         } else {
 713                                 break;
 714                         }
 715                 }
 716         }
 717
 718 end:
 719         if (i == 1)
 720                 matched_inode_no = search_dir(first_inode, ptr[i]);
 721         else
 722                 matched_inode_no = search_dir(parent_inode, ptr[i]);
 723
 724         if (matched_inode_no != -1) {
 725                 ext4fs_iget(matched_inode_no, &temp_inode);
 726                 if (le16_to_cpu(temp_inode.mode) & S_IFDIR) {
 727                         printf("It is a Directory\n");
 728                         result_inode_no = -1;
 729                         goto fail;
 730                 }
 731         }
 732
 733         if (strlen(ptr[i]) > 256) {
 734                 result_inode_no = -1;
 735                 goto fail;
 736         }
 737         memcpy(dname, ptr[i], strlen(ptr[i]));
 738
 739 fail:
 740         free(depth_dirname);
 741         free(parse_dirname);
 742         for (i = 0; i < depth; i++) {
 743                 if (!ptr[i])
 744                         break;
 745                 free(ptr[i]);
 746         }
 747         free(ptr);
 748         free(parent_inode);
 749         free(first_inode);
 750
 751         return result_inode_no;
 752 }
 753
 754 static int unlink_filename(char *filename, unsigned int blknr)
 755 {
 756         int totalbytes = 0;
 757         int templength = 0;
 758         int status, inodeno;
 759         int found = 0;
 760         char *root_first_block_buffer = NULL;
 761         struct ext2_dirent *dir = NULL;
 762         struct ext2_dirent *previous_dir = NULL;
 763         char *ptr = NULL;
 764         struct ext_filesystem *fs = get_fs();
 765         int ret = -1;
 766
 767         /* get the first block of root */
 768         root_first_block_buffer = zalloc(fs->blksz);
 769         if (!root_first_block_buffer)
 770                 return -ENOMEM;
 771         status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk, 0,
 772                                 fs->blksz, root_first_block_buffer);
 773         if (status == 0)
 774                 goto fail;
 775
 776         if (ext4fs_log_journal(root_first_block_buffer, blknr))
 777                 goto fail;
 778         dir = (struct ext2_dirent *)root_first_block_buffer;
 779         ptr = (char *)dir;
 780         totalbytes = 0;
 781         while (le16_to_cpu(dir->direntlen) >= 0) {
 782                 /*
 783                  * blocksize-totalbytes because last
 784                  * directory length i.e., *dir->direntlen
 785                  * is free availble space in the block that
 786                  * means it is a last entry of directory entry
 787                  */
 788                 if (dir->inode && (strlen(filename) == dir->namelen) &&
 789                     (strncmp(ptr + sizeof(struct ext2_dirent),
 790                              filename, dir->namelen) == 0)) {
 791                         printf("file found, deleting\n");
 792                         inodeno = le32_to_cpu(dir->inode);
 793                         if (previous_dir) {
 794                                 uint16_t new_len;
 795                                 new_len = le16_to_cpu(previous_dir->direntlen);
 796                                 new_len += le16_to_cpu(dir->direntlen);
 797                                 previous_dir->direntlen = cpu_to_le16(new_len);
 798                         } else {
 799                                 dir->inode = 0;
 800                         }
 801                         found = 1;
 802                         break;
 803                 }
 804
 805                 if (fs->blksz - totalbytes == le16_to_cpu(dir->direntlen))
 806                         break;
 807
 808                 /* traversing the each directory entry */
 809                 templength = le16_to_cpu(dir->direntlen);
 810                 totalbytes = totalbytes + templength;
 811                 previous_dir = dir;
 812                 dir = (struct ext2_dirent *)((char *)dir + templength);
 813                 ptr = (char *)dir;
 814         }
 815
 816
 817         if (found == 1) {
 818                 if (ext4fs_put_metadata(root_first_block_buffer, blknr))
 819                         goto fail;
 820                 ret = inodeno;
 821         }
 822 fail:
 823         free(root_first_block_buffer);
 824
 825         return ret;
 826 }
 827
 828 int ext4fs_filename_unlink(char *filename)
 829 {
 830         int blk_idx;
 831         long int blknr = -1;
 832         int inodeno = -1;
 833         uint32_t directory_blocks;
 834
 835         directory_blocks = le32_to_cpu(g_parent_inode->size) >>
 836                 LOG2_BLOCK_SIZE(ext4fs_root);
 837
 838         /* read the block no allocated to a file */
 839         for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
 840                 blknr = read_allocated_block(g_parent_inode, blk_idx);
 841                 if (blknr == 0)
 842                         break;
 843                 inodeno = unlink_filename(filename, blknr);
 844                 if (inodeno != -1)
 845                         return inodeno;
 846         }
 847
 848         return -1;
 849 }
 850
 851 uint32_t ext4fs_get_new_blk_no(void)
 852 {
 853         short i;
 854         short status;
 855         int remainder;
 856         unsigned int bg_idx;
 857         static int prev_bg_bitmap_index = -1;
 858         unsigned int blk_per_grp = le32_to_cpu(ext4fs_root->sblock.blocks_per_group);
 859         struct ext_filesystem *fs = get_fs();
 860         char *journal_buffer = zalloc(fs->blksz);
 861         char *zero_buffer = zalloc(fs->blksz);
 862         if (!journal_buffer || !zero_buffer)
 863                 goto fail;
 864         struct ext2_block_group *bgd = (struct ext2_block_group *)fs->gdtable;
 865
 866         if (fs->first_pass_bbmap == 0) {
 867                 for (i = 0; i < fs->no_blkgrp; i++) {
 868                         if (le16_to_cpu(bgd[i].free_blocks)) {
 869                                 if (le16_to_cpu(bgd[i].bg_flags) & EXT4_BG_BLOCK_UNINIT) {
 870                                         uint16_t new_flags;
 871                                         put_ext4((uint64_t)le32_to_cpu(bgd[i].block_id) * fs->blksz,
 872                                                  zero_buffer, fs->blksz);
 873                                         new_flags = le16_to_cpu(bgd[i].bg_flags) & ~EXT4_BG_BLOCK_UNINIT;
 874                                         bgd[i].bg_flags = cpu_to_le16(new_flags);
 875                                         memcpy(fs->blk_bmaps[i], zero_buffer,
 876                                                fs->blksz);
 877                                 }
 878                                 fs->curr_blkno =
 879                                     _get_new_blk_no(fs->blk_bmaps[i]);
 880                                 if (fs->curr_blkno == -1)
 881                                         /* if block bitmap is completely fill */
 882                                         continue;
 883                                 fs->curr_blkno = fs->curr_blkno +
 884                                                 (i * fs->blksz * 8);
 885                                 fs->first_pass_bbmap++;
 886                                 ext4fs_bg_free_blocks_dec(&bgd[i]);
 887                                 ext4fs_sb_free_blocks_dec(fs->sb);
 888                                 status = ext4fs_devread(
 889                                                         (lbaint_t)le32_to_cpu(bgd[i].block_id) *
 890                                                         fs->sect_perblk, 0,
 891                                                         fs->blksz,
 892                                                         journal_buffer);
 893                                 if (status == 0)
 894                                         goto fail;
 895                                 if (ext4fs_log_journal(journal_buffer,
 896                                                         le32_to_cpu(bgd[i].block_id)))
 897                                         goto fail;
 898                                 goto success;
 899                         } else {
 900                                 debug("no space left on block group %d\n", i);
 901                         }
 902                 }
 903
 904                 goto fail;
 905         } else {
 906                 fs->curr_blkno++;
 907 restart:
 908                 /* get the blockbitmap index respective to blockno */
 909                 bg_idx = fs->curr_blkno / blk_per_grp;
 910                 if (fs->blksz == 1024) {
 911                         remainder = fs->curr_blkno % blk_per_grp;
 912                         if (!remainder)
 913                                 bg_idx--;
 914                 }
 915
 916                 /*
 917                  * To skip completely filled block group bitmaps
 918                  * Optimize the block allocation
 919                  */
 920                 if (bg_idx >= fs->no_blkgrp)
 921                         goto fail;
 922
 923                 if (bgd[bg_idx].free_blocks == 0) {
 924                         debug("block group %u is full. Skipping\n", bg_idx);
 925                         fs->curr_blkno = (bg_idx + 1) * blk_per_grp;
 926                         if (fs->blksz == 1024)
 927                                 fs->curr_blkno += 1;
 928                         goto restart;
 929                 }
 930
 931                 if (le16_to_cpu(bgd[bg_idx].bg_flags) & EXT4_BG_BLOCK_UNINIT) {
 932                         uint16_t new_flags;
 933                         put_ext4((uint64_t)le32_to_cpu(bgd[bg_idx].block_id) * fs->blksz,
 934                                  zero_buffer, fs->blksz);
 935                         memcpy(fs->blk_bmaps[bg_idx], zero_buffer, fs->blksz);
 936                         new_flags = le16_to_cpu(bgd[bg_idx].bg_flags) & ~EXT4_BG_BLOCK_UNINIT;
 937                         bgd[bg_idx].bg_flags = cpu_to_le16(new_flags);
 938                 }
 939
 940                 if (ext4fs_set_block_bmap(fs->curr_blkno, fs->blk_bmaps[bg_idx],
 941                                    bg_idx) != 0) {
 942                         debug("going for restart for the block no %ld %u\n",
 943                               fs->curr_blkno, bg_idx);
 944                         fs->curr_blkno++;
 945                         goto restart;
 946                 }
 947
 948                 /* journal backup */
 949                 if (prev_bg_bitmap_index != bg_idx) {
 950                         status = ext4fs_devread(
 951                                                 (lbaint_t)le32_to_cpu(bgd[bg_idx].block_id)
 952                                                 * fs->sect_perblk,
 953                                                 0, fs->blksz, journal_buffer);
 954                         if (status == 0)
 955                                 goto fail;
 956                         if (ext4fs_log_journal(journal_buffer,
 957                                                 le32_to_cpu(bgd[bg_idx].block_id)))
 958                                 goto fail;
 959
 960                         prev_bg_bitmap_index = bg_idx;
 961                 }
 962                 ext4fs_bg_free_blocks_dec(&bgd[bg_idx]);
 963                 ext4fs_sb_free_blocks_dec(fs->sb);
 964                 goto success;
 965         }
 966 success:
 967         free(journal_buffer);
 968         free(zero_buffer);
 969
 970         return fs->curr_blkno;
 971 fail:
 972         free(journal_buffer);
 973         free(zero_buffer);
 974
 975         return -1;
 976 }
 977
 978 int ext4fs_get_new_inode_no(void)
 979 {
 980         short i;
 981         short status;
 982         unsigned int ibmap_idx;
 983         static int prev_inode_bitmap_index = -1;
 984         unsigned int inodes_per_grp = le32_to_cpu(ext4fs_root->sblock.inodes_per_group);
 985         struct ext_filesystem *fs = get_fs();
 986         char *journal_buffer = zalloc(fs->blksz);
 987         char *zero_buffer = zalloc(fs->blksz);
 988         if (!journal_buffer || !zero_buffer)
 989                 goto fail;
 990         struct ext2_block_group *bgd = (struct ext2_block_group *)fs->gdtable;
 991         int has_gdt_chksum = le32_to_cpu(fs->sb->feature_ro_compat) &
 992                 EXT4_FEATURE_RO_COMPAT_GDT_CSUM ? 1 : 0;
 993
 994         if (fs->first_pass_ibmap == 0) {
 995                 for (i = 0; i < fs->no_blkgrp; i++) {
 996                         if (bgd[i].free_inodes) {
 997                                 if (has_gdt_chksum)
 998                                         bgd[i].bg_itable_unused =
 999                                                 bgd[i].free_inodes;
1000                                 if (le16_to_cpu(bgd[i].bg_flags) & EXT4_BG_INODE_UNINIT) {
1001                                         int new_flags;
1002                                         put_ext4((uint64_t)le32_to_cpu(bgd[i].inode_id) * fs->blksz,
1003                                                  zero_buffer, fs->blksz);
1004                                         new_flags = le16_to_cpu(bgd[i].bg_flags) & ~EXT4_BG_INODE_UNINIT;
1005                                         bgd[i].bg_flags = cpu_to_le16(new_flags);
1006                                         memcpy(fs->inode_bmaps[i],
1007                                                zero_buffer, fs->blksz);
1008                                 }
1009                                 fs->curr_inode_no =
1010                                     _get_new_inode_no(fs->inode_bmaps[i]);
1011                                 if (fs->curr_inode_no == -1)
1012                                         /* if block bitmap is completely fill */
1013                                         continue;
1014                                 fs->curr_inode_no = fs->curr_inode_no +
1015                                                         (i * inodes_per_grp);
1016                                 fs->first_pass_ibmap++;
1017                                 ext4fs_bg_free_inodes_dec(&bgd[i]);
1018                                 if (has_gdt_chksum)
1019                                         ext4fs_bg_itable_unused_dec(&bgd[i]);
1020                                 ext4fs_sb_free_inodes_dec(fs->sb);
1021                                 status = ext4fs_devread(
1022                                                         (lbaint_t)le32_to_cpu(bgd[i].inode_id) *
1023                                                         fs->sect_perblk, 0,
1024                                                         fs->blksz,
1025                                                         journal_buffer);
1026                                 if (status == 0)
1027                                         goto fail;
1028                                 if (ext4fs_log_journal(journal_buffer,
1029                                                         le32_to_cpu(bgd[i].inode_id)))
1030                                         goto fail;
1031                                 goto success;
1032                         } else
1033                                 debug("no inode left on block group %d\n", i);
1034                 }
1035                 goto fail;
1036         } else {
1037 restart:
1038                 fs->curr_inode_no++;
1039                 /* get the blockbitmap index respective to blockno */
1040                 ibmap_idx = fs->curr_inode_no / inodes_per_grp;
1041                 if (le16_to_cpu(bgd[ibmap_idx].bg_flags) & EXT4_BG_INODE_UNINIT) {
1042                         int new_flags;
1043                         put_ext4((uint64_t)le32_to_cpu(bgd[ibmap_idx].inode_id) * fs->blksz,
1044                                  zero_buffer, fs->blksz);
1045                         new_flags = le16_to_cpu(bgd[ibmap_idx].bg_flags) & ~EXT4_BG_INODE_UNINIT;
1046                         bgd[ibmap_idx].bg_flags = cpu_to_le16(new_flags);
1047                         memcpy(fs->inode_bmaps[ibmap_idx], zero_buffer,
1048                                 fs->blksz);
1049                 }
1050
1051                 if (ext4fs_set_inode_bmap(fs->curr_inode_no,
1052                                           fs->inode_bmaps[ibmap_idx],
1053                                           ibmap_idx) != 0) {
1054                         debug("going for restart for the block no %d %u\n",
1055                               fs->curr_inode_no, ibmap_idx);
1056                         goto restart;
1057                 }
1058
1059                 /* journal backup */
1060                 if (prev_inode_bitmap_index != ibmap_idx) {
1061                         memset(journal_buffer, '\0', fs->blksz);
1062                         status = ext4fs_devread(
1063                                                 (lbaint_t)le32_to_cpu(bgd[ibmap_idx].inode_id)
1064                                                 * fs->sect_perblk,
1065                                                 0, fs->blksz, journal_buffer);
1066                         if (status == 0)
1067                                 goto fail;
1068                         if (ext4fs_log_journal(journal_buffer,
1069                                                 le32_to_cpu(bgd[ibmap_idx].inode_id)))
1070                                 goto fail;
1071                         prev_inode_bitmap_index = ibmap_idx;
1072                 }
1073                 ext4fs_bg_free_inodes_dec(&bgd[ibmap_idx]);
1074                 if (has_gdt_chksum)
1075                         bgd[ibmap_idx].bg_itable_unused =
1076                                         bgd[ibmap_idx].free_inodes;
1077                 ext4fs_sb_free_inodes_dec(fs->sb);
1078                 goto success;
1079         }
1080
1081 success:
1082         free(journal_buffer);
1083         free(zero_buffer);
1084
1085         return fs->curr_inode_no;
1086 fail:
1087         free(journal_buffer);
1088         free(zero_buffer);
1089
1090         return -1;
1091
1092 }
1093
1094
1095 static void alloc_single_indirect_block(struct ext2_inode *file_inode,
1096                                         unsigned int *total_remaining_blocks,
1097                                         unsigned int *no_blks_reqd)
1098 {
1099         short i;
1100         short status;
1101         long int actual_block_no;
1102         long int si_blockno;
1103         /* si :single indirect */
1104         __le32 *si_buffer = NULL;
1105         __le32 *si_start_addr = NULL;
1106         struct ext_filesystem *fs = get_fs();
1107
1108         if (*total_remaining_blocks != 0) {
1109                 si_buffer = zalloc(fs->blksz);
1110                 if (!si_buffer) {
1111                         printf("No Memory\n");
1112                         return;
1113                 }
1114                 si_start_addr = si_buffer;
1115                 si_blockno = ext4fs_get_new_blk_no();
1116                 if (si_blockno == -1) {
1117                         printf("no block left to assign\n");
1118                         goto fail;
1119                 }
1120                 (*no_blks_reqd)++;
1121                 debug("SIPB %ld: %u\n", si_blockno, *total_remaining_blocks);
1122
1123                 status = ext4fs_devread((lbaint_t)si_blockno * fs->sect_perblk,
1124                                         0, fs->blksz, (char *)si_buffer);
1125                 memset(si_buffer, '\0', fs->blksz);
1126                 if (status == 0)
1127                         goto fail;
1128
1129                 for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1130                         actual_block_no = ext4fs_get_new_blk_no();
1131                         if (actual_block_no == -1) {
1132                                 printf("no block left to assign\n");
1133                                 goto fail;
1134                         }
1135                         *si_buffer = cpu_to_le32(actual_block_no);
1136                         debug("SIAB %u: %u\n", *si_buffer,
1137                                 *total_remaining_blocks);
1138
1139                         si_buffer++;
1140                         (*total_remaining_blocks)--;
1141                         if (*total_remaining_blocks == 0)
1142                                 break;
1143                 }
1144
1145                 /* write the block to disk */
1146                 put_ext4(((uint64_t) ((uint64_t)si_blockno * (uint64_t)fs->blksz)),
1147                          si_start_addr, fs->blksz);
1148                 file_inode->b.blocks.indir_block = cpu_to_le32(si_blockno);
1149         }
1150 fail:
1151         free(si_start_addr);
1152 }
1153
1154 static void alloc_double_indirect_block(struct ext2_inode *file_inode,
1155                                         unsigned int *total_remaining_blocks,
1156                                         unsigned int *no_blks_reqd)
1157 {
1158         short i;
1159         short j;
1160         short status;
1161         long int actual_block_no;
1162         /* di:double indirect */
1163         long int di_blockno_parent;
1164         long int di_blockno_child;
1165         __le32 *di_parent_buffer = NULL;
1166         __le32 *di_child_buff = NULL;
1167         __le32 *di_block_start_addr = NULL;
1168         __le32 *di_child_buff_start = NULL;
1169         struct ext_filesystem *fs = get_fs();
1170
1171         if (*total_remaining_blocks != 0) {
1172                 /* double indirect parent block connecting to inode */
1173                 di_blockno_parent = ext4fs_get_new_blk_no();
1174                 if (di_blockno_parent == -1) {
1175                         printf("no block left to assign\n");
1176                         goto fail;
1177                 }
1178                 di_parent_buffer = zalloc(fs->blksz);
1179                 if (!di_parent_buffer)
1180                         goto fail;
1181
1182                 di_block_start_addr = di_parent_buffer;
1183                 (*no_blks_reqd)++;
1184                 debug("DIPB %ld: %u\n", di_blockno_parent,
1185                       *total_remaining_blocks);
1186
1187                 status = ext4fs_devread((lbaint_t)di_blockno_parent *
1188                                         fs->sect_perblk, 0,
1189                                         fs->blksz, (char *)di_parent_buffer);
1190
1191                 if (!status) {
1192                         printf("%s: Device read error!\n", __func__);
1193                         goto fail;
1194                 }
1195                 memset(di_parent_buffer, '\0', fs->blksz);
1196
1197                 /*
1198                  * start:for each double indirect parent
1199                  * block create one more block
1200                  */
1201                 for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1202                         di_blockno_child = ext4fs_get_new_blk_no();
1203                         if (di_blockno_child == -1) {
1204                                 printf("no block left to assign\n");
1205                                 goto fail;
1206                         }
1207                         di_child_buff = zalloc(fs->blksz);
1208                         if (!di_child_buff)
1209                                 goto fail;
1210
1211                         di_child_buff_start = di_child_buff;
1212                         *di_parent_buffer = cpu_to_le32(di_blockno_child);
1213                         di_parent_buffer++;
1214                         (*no_blks_reqd)++;
1215                         debug("DICB %ld: %u\n", di_blockno_child,
1216                               *total_remaining_blocks);
1217
1218                         status = ext4fs_devread((lbaint_t)di_blockno_child *
1219                                                 fs->sect_perblk, 0,
1220                                                 fs->blksz,
1221                                                 (char *)di_child_buff);
1222
1223                         if (!status) {
1224                                 printf("%s: Device read error!\n", __func__);
1225                                 goto fail;
1226                         }
1227                         memset(di_child_buff, '\0', fs->blksz);
1228                         /* filling of actual datablocks for each child */
1229                         for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1230                                 actual_block_no = ext4fs_get_new_blk_no();
1231                                 if (actual_block_no == -1) {
1232                                         printf("no block left to assign\n");
1233                                         goto fail;
1234                                 }
1235                                 *di_child_buff = cpu_to_le32(actual_block_no);
1236                                 debug("DIAB %ld: %u\n", actual_block_no,
1237                                       *total_remaining_blocks);
1238
1239                                 di_child_buff++;
1240                                 (*total_remaining_blocks)--;
1241                                 if (*total_remaining_blocks == 0)
1242                                         break;
1243                         }
1244                         /* write the block  table */
1245                         put_ext4(((uint64_t) ((uint64_t)di_blockno_child * (uint64_t)fs->blksz)),
1246                                  di_child_buff_start, fs->blksz);
1247                         free(di_child_buff_start);
1248                         di_child_buff_start = NULL;
1249
1250                         if (*total_remaining_blocks == 0)
1251                                 break;
1252                 }
1253                 put_ext4(((uint64_t) ((uint64_t)di_blockno_parent * (uint64_t)fs->blksz)),
1254                          di_block_start_addr, fs->blksz);
1255                 file_inode->b.blocks.double_indir_block = cpu_to_le32(di_blockno_parent);
1256         }
1257 fail:
1258         free(di_block_start_addr);
1259 }
1260
1261 static void alloc_triple_indirect_block(struct ext2_inode *file_inode,
1262                                         unsigned int *total_remaining_blocks,
1263                                         unsigned int *no_blks_reqd)
1264 {
1265         short i;
1266         short j;
1267         short k;
1268         long int actual_block_no;
1269         /* ti: Triple Indirect */
1270         long int ti_gp_blockno;
1271         long int ti_parent_blockno;
1272         long int ti_child_blockno;
1273         __le32 *ti_gp_buff = NULL;
1274         __le32 *ti_parent_buff = NULL;
1275         __le32 *ti_child_buff = NULL;
1276         __le32 *ti_gp_buff_start_addr = NULL;
1277         __le32 *ti_pbuff_start_addr = NULL;
1278         __le32 *ti_cbuff_start_addr = NULL;
1279         struct ext_filesystem *fs = get_fs();
1280         if (*total_remaining_blocks != 0) {
1281                 /* triple indirect grand parent block connecting to inode */
1282                 ti_gp_blockno = ext4fs_get_new_blk_no();
1283                 if (ti_gp_blockno == -1) {
1284                         printf("no block left to assign\n");
1285                         return;
1286                 }
1287                 ti_gp_buff = zalloc(fs->blksz);
1288                 if (!ti_gp_buff)
1289                         return;
1290
1291                 ti_gp_buff_start_addr = ti_gp_buff;
1292                 (*no_blks_reqd)++;
1293                 debug("TIGPB %ld: %u\n", ti_gp_blockno,
1294                       *total_remaining_blocks);
1295
1296                 /* for each 4 byte grand parent entry create one more block */
1297                 for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1298                         ti_parent_blockno = ext4fs_get_new_blk_no();
1299                         if (ti_parent_blockno == -1) {
1300                                 printf("no block left to assign\n");
1301                                 goto fail;
1302                         }
1303                         ti_parent_buff = zalloc(fs->blksz);
1304                         if (!ti_parent_buff)
1305                                 goto fail;
1306
1307                         ti_pbuff_start_addr = ti_parent_buff;
1308                         *ti_gp_buff = cpu_to_le32(ti_parent_blockno);
1309                         ti_gp_buff++;
1310                         (*no_blks_reqd)++;
1311                         debug("TIPB %ld: %u\n", ti_parent_blockno,
1312                               *total_remaining_blocks);
1313
1314                         /* for each 4 byte entry parent create one more block */
1315                         for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1316                                 ti_child_blockno = ext4fs_get_new_blk_no();
1317                                 if (ti_child_blockno == -1) {
1318                                         printf("no block left assign\n");
1319                                         goto fail1;
1320                                 }
1321                                 ti_child_buff = zalloc(fs->blksz);
1322                                 if (!ti_child_buff)
1323                                         goto fail1;
1324
1325                                 ti_cbuff_start_addr = ti_child_buff;
1326                                 *ti_parent_buff = cpu_to_le32(ti_child_blockno);
1327                                 ti_parent_buff++;
1328                                 (*no_blks_reqd)++;
1329                                 debug("TICB %ld: %u\n", ti_parent_blockno,
1330                                       *total_remaining_blocks);
1331
1332                                 /* fill actual datablocks for each child */
1333                                 for (k = 0; k < (fs->blksz / sizeof(int));
1334                                         k++) {
1335                                         actual_block_no =
1336                                             ext4fs_get_new_blk_no();
1337                                         if (actual_block_no == -1) {
1338                                                 printf("no block left\n");
1339                                                 free(ti_cbuff_start_addr);
1340                                                 goto fail1;
1341                                         }
1342                                         *ti_child_buff = cpu_to_le32(actual_block_no);
1343                                         debug("TIAB %ld: %u\n", actual_block_no,
1344                                               *total_remaining_blocks);
1345
1346                                         ti_child_buff++;
1347                                         (*total_remaining_blocks)--;
1348                                         if (*total_remaining_blocks == 0)
1349                                                 break;
1350                                 }
1351                                 /* write the child block */
1352                                 put_ext4(((uint64_t) ((uint64_t)ti_child_blockno *
1353                                                       (uint64_t)fs->blksz)),
1354                                          ti_cbuff_start_addr, fs->blksz);
1355                                 free(ti_cbuff_start_addr);
1356
1357                                 if (*total_remaining_blocks == 0)
1358                                         break;
1359                         }
1360                         /* write the parent block */
1361                         put_ext4(((uint64_t) ((uint64_t)ti_parent_blockno * (uint64_t)fs->blksz)),
1362                                  ti_pbuff_start_addr, fs->blksz);
1363                         free(ti_pbuff_start_addr);
1364
1365                         if (*total_remaining_blocks == 0)
1366                                 break;
1367                 }
1368                 /* write the grand parent block */
1369                 put_ext4(((uint64_t) ((uint64_t)ti_gp_blockno * (uint64_t)fs->blksz)),
1370                          ti_gp_buff_start_addr, fs->blksz);
1371                 file_inode->b.blocks.triple_indir_block = cpu_to_le32(ti_gp_blockno);
1372                 free(ti_gp_buff_start_addr);
1373                 return;
1374         }
1375 fail1:
1376         free(ti_pbuff_start_addr);
1377 fail:
1378         free(ti_gp_buff_start_addr);
1379 }
1380
1381 void ext4fs_allocate_blocks(struct ext2_inode *file_inode,
1382                                 unsigned int total_remaining_blocks,
1383                                 unsigned int *total_no_of_block)
1384 {
1385         short i;
1386         long int direct_blockno;
1387         unsigned int no_blks_reqd = 0;
1388
1389         /* allocation of direct blocks */
1390         for (i = 0; total_remaining_blocks && i < INDIRECT_BLOCKS; i++) {
1391                 direct_blockno = ext4fs_get_new_blk_no();
1392                 if (direct_blockno == -1) {
1393                         printf("no block left to assign\n");
1394                         return;
1395                 }
1396                 file_inode->b.blocks.dir_blocks[i] = cpu_to_le32(direct_blockno);
1397                 debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks);
1398
1399                 total_remaining_blocks--;
1400         }
1401
1402         alloc_single_indirect_block(file_inode, &total_remaining_blocks,
1403                                     &no_blks_reqd);
1404         alloc_double_indirect_block(file_inode, &total_remaining_blocks,
1405                                     &no_blks_reqd);
1406         alloc_triple_indirect_block(file_inode, &total_remaining_blocks,
1407                                     &no_blks_reqd);
1408         *total_no_of_block += no_blks_reqd;
1409 }
1410
1411 #endif
1412
1413 static struct ext4_extent_header *ext4fs_get_extent_block
1414         (struct ext2_data *data, char *buf,
1415                 struct ext4_extent_header *ext_block,
1416                 uint32_t fileblock, int log2_blksz)
1417 {
1418         struct ext4_extent_idx *index;
1419         unsigned long long block;
1420         int blksz = EXT2_BLOCK_SIZE(data);
1421         int i;
1422
1423         while (1) {
1424                 index = (struct ext4_extent_idx *)(ext_block + 1);
1425
1426                 if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
1427                         return NULL;
1428
1429                 if (ext_block->eh_depth == 0)
1430                         return ext_block;
1431                 i = -1;
1432                 do {
1433                         i++;
1434                         if (i >= le16_to_cpu(ext_block->eh_entries))
1435                                 break;
1436                 } while (fileblock >= le32_to_cpu(index[i].ei_block));
1437
1438                 if (--i < 0)
1439                         return NULL;
1440
1441                 block = le16_to_cpu(index[i].ei_leaf_hi);
1442                 block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
1443
1444                 if (ext4fs_devread((lbaint_t)block << log2_blksz, 0, blksz,
1445                                    buf))
1446                         ext_block = (struct ext4_extent_header *)buf;
1447                 else
1448                         return NULL;
1449         }
1450 }
1451
1452 static int ext4fs_blockgroup
1453         (struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
1454 {
1455         long int blkno;
1456         unsigned int blkoff, desc_per_blk;
1457         int log2blksz = get_fs()->dev_desc->log2blksz;
1458
1459         desc_per_blk = EXT2_BLOCK_SIZE(data) / sizeof(struct ext2_block_group);
1460
1461         blkno = le32_to_cpu(data->sblock.first_data_block) + 1 +
1462                         group / desc_per_blk;
1463         blkoff = (group % desc_per_blk) * sizeof(struct ext2_block_group);
1464
1465         debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n",
1466               group, blkno, blkoff);
1467
1468         return ext4fs_devread((lbaint_t)blkno <<
1469                               (LOG2_BLOCK_SIZE(data) - log2blksz),
1470                               blkoff, sizeof(struct ext2_block_group),
1471                               (char *)blkgrp);
1472 }
1473
1474 int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
1475 {
1476         struct ext2_block_group blkgrp;
1477         struct ext2_sblock *sblock = &data->sblock;
1478         struct ext_filesystem *fs = get_fs();
1479         int log2blksz = get_fs()->dev_desc->log2blksz;
1480         int inodes_per_block, status;
1481         long int blkno;
1482         unsigned int blkoff;
1483
1484         /* It is easier to calculate if the first inode is 0. */
1485         ino--;
1486         status = ext4fs_blockgroup(data, ino / le32_to_cpu
1487                                    (sblock->inodes_per_group), &blkgrp);
1488         if (status == 0)
1489                 return 0;
1490
1491         inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
1492         blkno = le32_to_cpu(blkgrp.inode_table_id) +
1493             (ino % le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
1494         blkoff = (ino % inodes_per_block) * fs->inodesz;
1495         /* Read the inode. */
1496         status = ext4fs_devread((lbaint_t)blkno << (LOG2_BLOCK_SIZE(data) -
1497                                 log2blksz), blkoff,
1498                                 sizeof(struct ext2_inode), (char *)inode);
1499         if (status == 0)
1500                 return 0;
1501
1502         return 1;
1503 }
1504
1505 long int read_allocated_block(struct ext2_inode *inode, int fileblock)
1506 {
1507         long int blknr;
1508         int blksz;
1509         int log2_blksz;
1510         int status;
1511         long int rblock;
1512         long int perblock_parent;
1513         long int perblock_child;
1514         unsigned long long start;
1515         /* get the blocksize of the filesystem */
1516         blksz = EXT2_BLOCK_SIZE(ext4fs_root);
1517         log2_blksz = LOG2_BLOCK_SIZE(ext4fs_root)
1518                 - get_fs()->dev_desc->log2blksz;
1519
1520         if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
1521                 char *buf = zalloc(blksz);
1522                 if (!buf)
1523                         return -ENOMEM;
1524                 struct ext4_extent_header *ext_block;
1525                 struct ext4_extent *extent;
1526                 int i = -1;
1527                 ext_block =
1528                         ext4fs_get_extent_block(ext4fs_root, buf,
1529                                                 (struct ext4_extent_header *)
1530                                                 inode->b.blocks.dir_blocks,
1531                                                 fileblock, log2_blksz);
1532                 if (!ext_block) {
1533                         printf("invalid extent block\n");
1534                         free(buf);
1535                         return -EINVAL;
1536                 }
1537
1538                 extent = (struct ext4_extent *)(ext_block + 1);
1539
1540                 do {
1541                         i++;
1542                         if (i >= le16_to_cpu(ext_block->eh_entries))
1543                                 break;
1544                 } while (fileblock >= le32_to_cpu(extent[i].ee_block));
1545                 if (--i >= 0) {
1546                         fileblock -= le32_to_cpu(extent[i].ee_block);
1547                         if (fileblock >= le16_to_cpu(extent[i].ee_len)) {
1548                                 free(buf);
1549                                 return 0;
1550                         }
1551
1552                         start = le16_to_cpu(extent[i].ee_start_hi);
1553                         start = (start << 32) +
1554                                         le32_to_cpu(extent[i].ee_start_lo);
1555                         free(buf);
1556                         return fileblock + start;
1557                 }
1558
1559                 printf("Extent Error\n");
1560                 free(buf);
1561                 return -1;
1562         }
1563
1564         /* Direct blocks. */
1565         if (fileblock < INDIRECT_BLOCKS)
1566                 blknr = le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);
1567
1568         /* Indirect. */
1569         else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
1570                 if (ext4fs_indir1_block == NULL) {
1571                         ext4fs_indir1_block = zalloc(blksz);
1572                         if (ext4fs_indir1_block == NULL) {
1573                                 printf("** SI ext2fs read block (indir 1)"
1574                                         "malloc failed. **\n");
1575                                 return -1;
1576                         }
1577                         ext4fs_indir1_size = blksz;
1578                         ext4fs_indir1_blkno = -1;
1579                 }
1580                 if (blksz != ext4fs_indir1_size) {
1581                         free(ext4fs_indir1_block);
1582                         ext4fs_indir1_block = NULL;
1583                         ext4fs_indir1_size = 0;
1584                         ext4fs_indir1_blkno = -1;
1585                         ext4fs_indir1_block = zalloc(blksz);
1586                         if (ext4fs_indir1_block == NULL) {
1587                                 printf("** SI ext2fs read block (indir 1):"
1588                                         "malloc failed. **\n");
1589                                 return -1;
1590                         }
1591                         ext4fs_indir1_size = blksz;
1592                 }
1593                 if ((le32_to_cpu(inode->b.blocks.indir_block) <<
1594                      log2_blksz) != ext4fs_indir1_blkno) {
1595                         status =
1596                             ext4fs_devread((lbaint_t)le32_to_cpu
1597                                            (inode->b.blocks.
1598                                             indir_block) << log2_blksz, 0,
1599                                            blksz, (char *)ext4fs_indir1_block);
1600                         if (status == 0) {
1601                                 printf("** SI ext2fs read block (indir 1)"
1602                                         "failed. **\n");
1603                                 return 0;
1604                         }
1605                         ext4fs_indir1_blkno =
1606                                 le32_to_cpu(inode->b.blocks.
1607                                                indir_block) << log2_blksz;
1608                 }
1609                 blknr = le32_to_cpu(ext4fs_indir1_block
1610                                       [fileblock - INDIRECT_BLOCKS]);
1611         }
1612         /* Double indirect. */
1613         else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 *
1614                                         (blksz / 4 + 1)))) {
1615
1616                 long int perblock = blksz / 4;
1617                 long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4);
1618
1619                 if (ext4fs_indir1_block == NULL) {
1620                         ext4fs_indir1_block = zalloc(blksz);
1621                         if (ext4fs_indir1_block == NULL) {
1622                                 printf("** DI ext2fs read block (indir 2 1)"
1623                                         "malloc failed. **\n");
1624                                 return -1;
1625                         }
1626                         ext4fs_indir1_size = blksz;
1627                         ext4fs_indir1_blkno = -1;
1628                 }
1629                 if (blksz != ext4fs_indir1_size) {
1630                         free(ext4fs_indir1_block);
1631                         ext4fs_indir1_block = NULL;
1632                         ext4fs_indir1_size = 0;
1633                         ext4fs_indir1_blkno = -1;
1634                         ext4fs_indir1_block = zalloc(blksz);
1635                         if (ext4fs_indir1_block == NULL) {
1636                                 printf("** DI ext2fs read block (indir 2 1)"
1637                                         "malloc failed. **\n");
1638                                 return -1;
1639                         }
1640                         ext4fs_indir1_size = blksz;
1641                 }
1642                 if ((le32_to_cpu(inode->b.blocks.double_indir_block) <<
1643                      log2_blksz) != ext4fs_indir1_blkno) {
1644                         status =
1645                             ext4fs_devread((lbaint_t)le32_to_cpu
1646                                            (inode->b.blocks.
1647                                             double_indir_block) << log2_blksz,
1648                                            0, blksz,
1649                                            (char *)ext4fs_indir1_block);
1650                         if (status == 0) {
1651                                 printf("** DI ext2fs read block (indir 2 1)"
1652                                         "failed. **\n");
1653                                 return -1;
1654                         }
1655                         ext4fs_indir1_blkno =
1656                             le32_to_cpu(inode->b.blocks.double_indir_block) <<
1657                             log2_blksz;
1658                 }
1659
1660                 if (ext4fs_indir2_block == NULL) {
1661                         ext4fs_indir2_block = zalloc(blksz);
1662                         if (ext4fs_indir2_block == NULL) {
1663                                 printf("** DI ext2fs read block (indir 2 2)"
1664                                         "malloc failed. **\n");
1665                                 return -1;
1666                         }
1667                         ext4fs_indir2_size = blksz;
1668                         ext4fs_indir2_blkno = -1;
1669                 }
1670                 if (blksz != ext4fs_indir2_size) {
1671                         free(ext4fs_indir2_block);
1672                         ext4fs_indir2_block = NULL;
1673                         ext4fs_indir2_size = 0;
1674                         ext4fs_indir2_blkno = -1;
1675                         ext4fs_indir2_block = zalloc(blksz);
1676                         if (ext4fs_indir2_block == NULL) {
1677                                 printf("** DI ext2fs read block (indir 2 2)"
1678                                         "malloc failed. **\n");
1679                                 return -1;
1680                         }
1681                         ext4fs_indir2_size = blksz;
1682                 }
1683                 if ((le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) <<
1684                      log2_blksz) != ext4fs_indir2_blkno) {
1685                         status = ext4fs_devread((lbaint_t)le32_to_cpu
1686                                                 (ext4fs_indir1_block
1687                                                  [rblock /
1688                                                   perblock]) << log2_blksz, 0,
1689                                                 blksz,
1690                                                 (char *)ext4fs_indir2_block);
1691                         if (status == 0) {
1692                                 printf("** DI ext2fs read block (indir 2 2)"
1693                                         "failed. **\n");
1694                                 return -1;
1695                         }
1696                         ext4fs_indir2_blkno =
1697                             le32_to_cpu(ext4fs_indir1_block[rblock
1698                                                               /
1699                                                               perblock]) <<
1700                             log2_blksz;
1701                 }
1702                 blknr = le32_to_cpu(ext4fs_indir2_block[rblock % perblock]);
1703         }
1704         /* Tripple indirect. */
1705         else {
1706                 rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 +
1707                                       (blksz / 4 * blksz / 4));
1708                 perblock_child = blksz / 4;
1709                 perblock_parent = ((blksz / 4) * (blksz / 4));
1710
1711                 if (ext4fs_indir1_block == NULL) {
1712                         ext4fs_indir1_block = zalloc(blksz);
1713                         if (ext4fs_indir1_block == NULL) {
1714                                 printf("** TI ext2fs read block (indir 2 1)"
1715                                         "malloc failed. **\n");
1716                                 return -1;
1717                         }
1718                         ext4fs_indir1_size = blksz;
1719                         ext4fs_indir1_blkno = -1;
1720                 }
1721                 if (blksz != ext4fs_indir1_size) {
1722                         free(ext4fs_indir1_block);
1723                         ext4fs_indir1_block = NULL;
1724                         ext4fs_indir1_size = 0;
1725                         ext4fs_indir1_blkno = -1;
1726                         ext4fs_indir1_block = zalloc(blksz);
1727                         if (ext4fs_indir1_block == NULL) {
1728                                 printf("** TI ext2fs read block (indir 2 1)"
1729                                         "malloc failed. **\n");
1730                                 return -1;
1731                         }
1732                         ext4fs_indir1_size = blksz;
1733                 }
1734                 if ((le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1735                      log2_blksz) != ext4fs_indir1_blkno) {
1736                         status = ext4fs_devread
1737                             ((lbaint_t)
1738                              le32_to_cpu(inode->b.blocks.triple_indir_block)
1739                              << log2_blksz, 0, blksz,
1740                              (char *)ext4fs_indir1_block);
1741                         if (status == 0) {
1742                                 printf("** TI ext2fs read block (indir 2 1)"
1743                                         "failed. **\n");
1744                                 return -1;
1745                         }
1746                         ext4fs_indir1_blkno =
1747                             le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1748                             log2_blksz;
1749                 }
1750
1751                 if (ext4fs_indir2_block == NULL) {
1752                         ext4fs_indir2_block = zalloc(blksz);
1753                         if (ext4fs_indir2_block == NULL) {
1754                                 printf("** TI ext2fs read block (indir 2 2)"
1755                                         "malloc failed. **\n");
1756                                 return -1;
1757                         }
1758                         ext4fs_indir2_size = blksz;
1759                         ext4fs_indir2_blkno = -1;
1760                 }
1761                 if (blksz != ext4fs_indir2_size) {
1762                         free(ext4fs_indir2_block);
1763                         ext4fs_indir2_block = NULL;
1764                         ext4fs_indir2_size = 0;
1765                         ext4fs_indir2_blkno = -1;
1766                         ext4fs_indir2_block = zalloc(blksz);
1767                         if (ext4fs_indir2_block == NULL) {
1768                                 printf("** TI ext2fs read block (indir 2 2)"
1769                                         "malloc failed. **\n");
1770                                 return -1;
1771                         }
1772                         ext4fs_indir2_size = blksz;
1773                 }
1774                 if ((le32_to_cpu(ext4fs_indir1_block[rblock /
1775                                                        perblock_parent]) <<
1776                      log2_blksz)
1777                     != ext4fs_indir2_blkno) {
1778                         status = ext4fs_devread((lbaint_t)le32_to_cpu
1779                                                 (ext4fs_indir1_block
1780                                                  [rblock /
1781                                                   perblock_parent]) <<
1782                                                 log2_blksz, 0, blksz,
1783                                                 (char *)ext4fs_indir2_block);
1784                         if (status == 0) {
1785                                 printf("** TI ext2fs read block (indir 2 2)"
1786                                         "failed. **\n");
1787                                 return -1;
1788                         }
1789                         ext4fs_indir2_blkno =
1790                             le32_to_cpu(ext4fs_indir1_block[rblock /
1791                                                               perblock_parent])
1792                             << log2_blksz;
1793                 }
1794
1795                 if (ext4fs_indir3_block == NULL) {
1796                         ext4fs_indir3_block = zalloc(blksz);
1797                         if (ext4fs_indir3_block == NULL) {
1798                                 printf("** TI ext2fs read block (indir 2 2)"
1799                                         "malloc failed. **\n");
1800                                 return -1;
1801                         }
1802                         ext4fs_indir3_size = blksz;
1803                         ext4fs_indir3_blkno = -1;
1804                 }
1805                 if (blksz != ext4fs_indir3_size) {
1806                         free(ext4fs_indir3_block);
1807                         ext4fs_indir3_block = NULL;
1808                         ext4fs_indir3_size = 0;
1809                         ext4fs_indir3_blkno = -1;
1810                         ext4fs_indir3_block = zalloc(blksz);
1811                         if (ext4fs_indir3_block == NULL) {
1812                                 printf("** TI ext2fs read block (indir 2 2)"
1813                                         "malloc failed. **\n");
1814                                 return -1;
1815                         }
1816                         ext4fs_indir3_size = blksz;
1817                 }
1818                 if ((le32_to_cpu(ext4fs_indir2_block[rblock
1819                                                        /
1820                                                        perblock_child]) <<
1821                      log2_blksz) != ext4fs_indir3_blkno) {
1822                         status =
1823                             ext4fs_devread((lbaint_t)le32_to_cpu
1824                                            (ext4fs_indir2_block
1825                                             [(rblock / perblock_child)
1826                                              % (blksz / 4)]) << log2_blksz, 0,
1827                                            blksz, (char *)ext4fs_indir3_block);
1828                         if (status == 0) {
1829                                 printf("** TI ext2fs read block (indir 2 2)"
1830                                        "failed. **\n");
1831                                 return -1;
1832                         }
1833                         ext4fs_indir3_blkno =
1834                             le32_to_cpu(ext4fs_indir2_block[(rblock /
1835                                                                perblock_child) %
1836                                                               (blksz /
1837                                                                4)]) <<
1838                             log2_blksz;
1839                 }
1840
1841                 blknr = le32_to_cpu(ext4fs_indir3_block
1842                                       [rblock % perblock_child]);
1843         }
1844         debug("read_allocated_block %ld\n", blknr);
1845
1846         return blknr;
1847 }
1848
1849 /**
1850  * ext4fs_reinit_global() - Reinitialize values of ext4 write implementation's
1851  *                          global pointers
1852  *
1853  * This function assures that for a file with the same name but different size
1854  * the sequential store on the ext4 filesystem will be correct.
1855  *
1856  * In this function the global data, responsible for internal representation
1857  * of the ext4 data are initialized to the reset state. Without this, during
1858  * replacement of the smaller file with the bigger truncation of new file was
1859  * performed.
1860  */
1861 void ext4fs_reinit_global(void)
1862 {
1863         if (ext4fs_indir1_block != NULL) {
1864                 free(ext4fs_indir1_block);
1865                 ext4fs_indir1_block = NULL;
1866                 ext4fs_indir1_size = 0;
1867                 ext4fs_indir1_blkno = -1;
1868         }
1869         if (ext4fs_indir2_block != NULL) {
1870                 free(ext4fs_indir2_block);
1871                 ext4fs_indir2_block = NULL;
1872                 ext4fs_indir2_size = 0;
1873                 ext4fs_indir2_blkno = -1;
1874         }
1875         if (ext4fs_indir3_block != NULL) {
1876                 free(ext4fs_indir3_block);
1877                 ext4fs_indir3_block = NULL;
1878                 ext4fs_indir3_size = 0;
1879                 ext4fs_indir3_blkno = -1;
1880         }
1881 }
1882 void ext4fs_close(void)
1883 {
1884         if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) {
1885                 ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen);
1886                 ext4fs_file = NULL;
1887         }
1888         if (ext4fs_root != NULL) {
1889                 free(ext4fs_root);
1890                 ext4fs_root = NULL;
1891         }
1892
1893         ext4fs_reinit_global();
1894 }
1895
1896 int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
1897                                 struct ext2fs_node **fnode, int *ftype)
1898 {
1899         unsigned int fpos = 0;
1900         int status;
1901         loff_t actread;
1902         struct ext2fs_node *diro = (struct ext2fs_node *) dir;
1903
1904 #ifdef DEBUG
1905         if (name != NULL)
1906                 printf("Iterate dir %s\n", name);
1907 #endif /* of DEBUG */
1908         if (!diro->inode_read) {
1909                 status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
1910                 if (status == 0)
1911                         return 0;
1912         }
1913         /* Search the file.  */
1914         while (fpos < le32_to_cpu(diro->inode.size)) {
1915                 struct ext2_dirent dirent;
1916
1917                 status = ext4fs_read_file(diro, fpos,
1918                                            sizeof(struct ext2_dirent),
1919                                            (char *)&dirent, &actread);
1920                 if (status < 0)
1921                         return 0;
1922
1923                 if (dirent.direntlen == 0) {
1924                         printf("Failed to iterate over directory %s\n", name);
1925                         return 0;
1926                 }
1927
1928                 if (dirent.namelen != 0) {
1929                         char filename[dirent.namelen + 1];
1930                         struct ext2fs_node *fdiro;
1931                         int type = FILETYPE_UNKNOWN;
1932
1933                         status = ext4fs_read_file(diro,
1934                                                   fpos +
1935                                                   sizeof(struct ext2_dirent),
1936                                                   dirent.namelen, filename,
1937                                                   &actread);
1938                         if (status < 0)
1939                                 return 0;
1940
1941                         fdiro = zalloc(sizeof(struct ext2fs_node));
1942                         if (!fdiro)
1943                                 return 0;
1944
1945                         fdiro->data = diro->data;
1946                         fdiro->ino = le32_to_cpu(dirent.inode);
1947
1948                         filename[dirent.namelen] = '\0';
1949
1950                         if (dirent.filetype != FILETYPE_UNKNOWN) {
1951                                 fdiro->inode_read = 0;
1952
1953                                 if (dirent.filetype == FILETYPE_DIRECTORY)
1954                                         type = FILETYPE_DIRECTORY;
1955                                 else if (dirent.filetype == FILETYPE_SYMLINK)
1956                                         type = FILETYPE_SYMLINK;
1957                                 else if (dirent.filetype == FILETYPE_REG)
1958                                         type = FILETYPE_REG;
1959                         } else {
1960                                 status = ext4fs_read_inode(diro->data,
1961                                                            le32_to_cpu
1962                                                            (dirent.inode),
1963                                                            &fdiro->inode);
1964                                 if (status == 0) {
1965                                         free(fdiro);
1966                                         return 0;
1967                                 }
1968                                 fdiro->inode_read = 1;
1969
1970                                 if ((le16_to_cpu(fdiro->inode.mode) &
1971                                      FILETYPE_INO_MASK) ==
1972                                     FILETYPE_INO_DIRECTORY) {
1973                                         type = FILETYPE_DIRECTORY;
1974                                 } else if ((le16_to_cpu(fdiro->inode.mode)
1975                                             & FILETYPE_INO_MASK) ==
1976                                            FILETYPE_INO_SYMLINK) {
1977                                         type = FILETYPE_SYMLINK;
1978                                 } else if ((le16_to_cpu(fdiro->inode.mode)
1979                                             & FILETYPE_INO_MASK) ==
1980                                            FILETYPE_INO_REG) {
1981                                         type = FILETYPE_REG;
1982                                 }
1983                         }
1984 #ifdef DEBUG
1985                         printf("iterate >%s<\n", filename);
1986 #endif /* of DEBUG */
1987                         if ((name != NULL) && (fnode != NULL)
1988                             && (ftype != NULL)) {
1989                                 if (strcmp(filename, name) == 0) {
1990                                         *ftype = type;
1991                                         *fnode = fdiro;
1992                                         return 1;
1993                                 }
1994                         } else {
1995                                 if (fdiro->inode_read == 0) {
1996                                         status = ext4fs_read_inode(diro->data,
1997                                                                  le32_to_cpu(
1998                                                                  dirent.inode),
1999                                                                  &fdiro->inode);
2000                                         if (status == 0) {
2001                                                 free(fdiro);
2002                                                 return 0;
2003                                         }
2004                                         fdiro->inode_read = 1;
2005                                 }
2006                                 switch (type) {
2007                                 case FILETYPE_DIRECTORY:
2008                                         printf("<DIR> ");
2009                                         break;
2010                                 case FILETYPE_SYMLINK:
2011                                         printf("<SYM> ");
2012                                         break;
2013                                 case FILETYPE_REG:
2014                                         printf("      ");
2015                                         break;
2016                                 default:
2017                                         printf("< ? > ");
2018                                         break;
2019                                 }
2020                                 printf("%10u %s\n",
2021                                        le32_to_cpu(fdiro->inode.size),
2022                                         filename);
2023                         }
2024                         free(fdiro);
2025                 }
2026                 fpos += le16_to_cpu(dirent.direntlen);
2027         }
2028         return 0;
2029 }
2030
2031 static char *ext4fs_read_symlink(struct ext2fs_node *node)
2032 {
2033         char *symlink;
2034         struct ext2fs_node *diro = node;
2035         int status;
2036         loff_t actread;
2037
2038         if (!diro->inode_read) {
2039                 status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2040                 if (status == 0)
2041                         return NULL;
2042         }
2043         symlink = zalloc(le32_to_cpu(diro->inode.size) + 1);
2044         if (!symlink)
2045                 return NULL;
2046
2047         if (le32_to_cpu(diro->inode.size) < sizeof(diro->inode.b.symlink)) {
2048                 strncpy(symlink, diro->inode.b.symlink,
2049                          le32_to_cpu(diro->inode.size));
2050         } else {
2051                 status = ext4fs_read_file(diro, 0,
2052                                            le32_to_cpu(diro->inode.size),
2053                                            symlink, &actread);
2054                 if ((status < 0) || (actread == 0)) {
2055                         free(symlink);
2056                         return NULL;
2057                 }
2058         }
2059         symlink[le32_to_cpu(diro->inode.size)] = '\0';
2060         return symlink;
2061 }
2062
2063 static int ext4fs_find_file1(const char *currpath,
2064                              struct ext2fs_node *currroot,
2065                              struct ext2fs_node **currfound, int *foundtype)
2066 {
2067         char fpath[strlen(currpath) + 1];
2068         char *name = fpath;
2069         char *next;
2070         int status;
2071         int type = FILETYPE_DIRECTORY;
2072         struct ext2fs_node *currnode = currroot;
2073         struct ext2fs_node *oldnode = currroot;
2074
2075         strncpy(fpath, currpath, strlen(currpath) + 1);
2076
2077         /* Remove all leading slashes. */
2078         while (*name == '/')
2079                 name++;
2080
2081         if (!*name) {
2082                 *currfound = currnode;
2083                 return 1;
2084         }
2085
2086         for (;;) {
2087                 int found;
2088
2089                 /* Extract the actual part from the pathname. */
2090                 next = strchr(name, '/');
2091                 if (next) {
2092                         /* Remove all leading slashes. */
2093                         while (*next == '/')
2094                                 *(next++) = '\0';
2095                 }
2096
2097                 if (type != FILETYPE_DIRECTORY) {
2098                         ext4fs_free_node(currnode, currroot);
2099                         return 0;
2100                 }
2101
2102                 oldnode = currnode;
2103
2104                 /* Iterate over the directory. */
2105                 found = ext4fs_iterate_dir(currnode, name, &currnode, &type);
2106                 if (found == 0)
2107                         return 0;
2108
2109                 if (found == -1)
2110                         break;
2111
2112                 /* Read in the symlink and follow it. */
2113                 if (type == FILETYPE_SYMLINK) {
2114                         char *symlink;
2115
2116                         /* Test if the symlink does not loop. */
2117                         if (++symlinknest == 8) {
2118                                 ext4fs_free_node(currnode, currroot);
2119                                 ext4fs_free_node(oldnode, currroot);
2120                                 return 0;
2121                         }
2122
2123                         symlink = ext4fs_read_symlink(currnode);
2124                         ext4fs_free_node(currnode, currroot);
2125
2126                         if (!symlink) {
2127                                 ext4fs_free_node(oldnode, currroot);
2128                                 return 0;
2129                         }
2130
2131                         debug("Got symlink >%s<\n", symlink);
2132
2133                         if (symlink[0] == '/') {
2134                                 ext4fs_free_node(oldnode, currroot);
2135                                 oldnode = &ext4fs_root->diropen;
2136                         }
2137
2138                         /* Lookup the node the symlink points to. */
2139                         status = ext4fs_find_file1(symlink, oldnode,
2140                                                     &currnode, &type);
2141
2142                         free(symlink);
2143
2144                         if (status == 0) {
2145                                 ext4fs_free_node(oldnode, currroot);
2146                                 return 0;
2147                         }
2148                 }
2149
2150                 ext4fs_free_node(oldnode, currroot);
2151
2152                 /* Found the node! */
2153                 if (!next || *next == '\0') {
2154                         *currfound = currnode;
2155                         *foundtype = type;
2156                         return 1;
2157                 }
2158                 name = next;
2159         }
2160         return -1;
2161 }
2162
2163 int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
2164         struct ext2fs_node **foundnode, int expecttype)
2165 {
2166         int status;
2167         int foundtype = FILETYPE_DIRECTORY;
2168
2169         symlinknest = 0;
2170         if (!path)
2171                 return 0;
2172
2173         status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype);
2174         if (status == 0)
2175                 return 0;
2176
2177         /* Check if the node that was found was of the expected type. */
2178         if ((expecttype == FILETYPE_REG) && (foundtype != expecttype))
2179                 return 0;
2180         else if ((expecttype == FILETYPE_DIRECTORY)
2181                    && (foundtype != expecttype))
2182                 return 0;
2183
2184         return 1;
2185 }
2186
2187 int ext4fs_open(const char *filename, loff_t *len)
2188 {
2189         struct ext2fs_node *fdiro = NULL;
2190         int status;
2191
2192         if (ext4fs_root == NULL)
2193                 return -1;
2194
2195         ext4fs_file = NULL;
2196         status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro,
2197                                   FILETYPE_REG);
2198         if (status == 0)
2199                 goto fail;
2200
2201         if (!fdiro->inode_read) {
2202                 status = ext4fs_read_inode(fdiro->data, fdiro->ino,
2203                                 &fdiro->inode);
2204                 if (status == 0)
2205                         goto fail;
2206         }
2207         *len = le32_to_cpu(fdiro->inode.size);
2208         ext4fs_file = fdiro;
2209
2210         return 0;
2211 fail:
2212         ext4fs_free_node(fdiro, &ext4fs_root->diropen);
2213
2214         return -1;
2215 }
2216
2217 int ext4fs_mount(unsigned part_length)
2218 {
2219         struct ext2_data *data;
2220         int status;
2221         struct ext_filesystem *fs = get_fs();
2222         data = zalloc(SUPERBLOCK_SIZE);
2223         if (!data)
2224                 return 0;
2225
2226         /* Read the superblock. */
2227         status = ext4_read_superblock((char *)&data->sblock);
2228
2229         if (status == 0)
2230                 goto fail;
2231
2232         /* Make sure this is an ext2 filesystem. */
2233         if (le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
2234                 goto fail;
2235
2236         /*
2237          * The 64bit feature was enabled when metadata_csum was enabled
2238          * and we do not support metadata_csum (and cannot reliably find
2239          * files when it is set.  Refuse to mount.
2240          */
2241         if (le32_to_cpu(data->sblock.feature_incompat) & EXT4_FEATURE_INCOMPAT_64BIT) {
2242                 printf("Unsupported feature found (64bit, possibly metadata_csum), not mounting\n");
2243                 goto fail;
2244         }
2245
2246         if (le32_to_cpu(data->sblock.revision_level) == 0)
2247                 fs->inodesz = 128;
2248         else
2249                 fs->inodesz = le16_to_cpu(data->sblock.inode_size);
2250
2251         debug("EXT2 rev %d, inode_size %d\n",
2252                le32_to_cpu(data->sblock.revision_level), fs->inodesz);
2253
2254         data->diropen.data = data;
2255         data->diropen.ino = 2;
2256         data->diropen.inode_read = 1;
2257         data->inode = &data->diropen.inode;
2258
2259         status = ext4fs_read_inode(data, 2, data->inode);
2260         if (status == 0)
2261                 goto fail;
2262
2263         ext4fs_root = data;
2264
2265         return 1;
2266 fail:
2267         printf("Failed to mount ext2 filesystem...\n");
2268         free(data);
2269         ext4fs_root = NULL;
2270
2271         return 0;
2272 }