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 restart:
 907                 fs->curr_blkno++;
 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 = fs->curr_blkno + blk_per_grp;
 926                         fs->curr_blkno--;
 927                         goto restart;
 928                 }
 929
 930                 if (le16_to_cpu(bgd[bg_idx].bg_flags) & EXT4_BG_BLOCK_UNINIT) {
 931                         uint16_t new_flags;
 932                         put_ext4((uint64_t)le32_to_cpu(bgd[bg_idx].block_id) * fs->blksz,
 933                                  zero_buffer, fs->blksz);
 934                         memcpy(fs->blk_bmaps[bg_idx], zero_buffer, fs->blksz);
 935                         new_flags = le16_to_cpu(bgd[bg_idx].bg_flags) & ~EXT4_BG_BLOCK_UNINIT;
 936                         bgd[bg_idx].bg_flags = cpu_to_le16(new_flags);
 937                 }
 938
 939                 if (ext4fs_set_block_bmap(fs->curr_blkno, fs->blk_bmaps[bg_idx],
 940                                    bg_idx) != 0) {
 941                         debug("going for restart for the block no %ld %u\n",
 942                               fs->curr_blkno, bg_idx);
 943                         goto restart;
 944                 }
 945
 946                 /* journal backup */
 947                 if (prev_bg_bitmap_index != bg_idx) {
 948                         status = ext4fs_devread(
 949                                                 (lbaint_t)le32_to_cpu(bgd[bg_idx].block_id)
 950                                                 * fs->sect_perblk,
 951                                                 0, fs->blksz, journal_buffer);
 952                         if (status == 0)
 953                                 goto fail;
 954                         if (ext4fs_log_journal(journal_buffer,
 955                                                 le32_to_cpu(bgd[bg_idx].block_id)))
 956                                 goto fail;
 957
 958                         prev_bg_bitmap_index = bg_idx;
 959                 }
 960                 ext4fs_bg_free_blocks_dec(&bgd[bg_idx]);
 961                 ext4fs_sb_free_blocks_dec(fs->sb);
 962                 goto success;
 963         }
 964 success:
 965         free(journal_buffer);
 966         free(zero_buffer);
 967
 968         return fs->curr_blkno;
 969 fail:
 970         free(journal_buffer);
 971         free(zero_buffer);
 972
 973         return -1;
 974 }
 975
 976 int ext4fs_get_new_inode_no(void)
 977 {
 978         short i;
 979         short status;
 980         unsigned int ibmap_idx;
 981         static int prev_inode_bitmap_index = -1;
 982         unsigned int inodes_per_grp = le32_to_cpu(ext4fs_root->sblock.inodes_per_group);
 983         struct ext_filesystem *fs = get_fs();
 984         char *journal_buffer = zalloc(fs->blksz);
 985         char *zero_buffer = zalloc(fs->blksz);
 986         if (!journal_buffer || !zero_buffer)
 987                 goto fail;
 988         struct ext2_block_group *bgd = (struct ext2_block_group *)fs->gdtable;
 989         int has_gdt_chksum = le32_to_cpu(fs->sb->feature_ro_compat) &
 990                 EXT4_FEATURE_RO_COMPAT_GDT_CSUM ? 1 : 0;
 991
 992         if (fs->first_pass_ibmap == 0) {
 993                 for (i = 0; i < fs->no_blkgrp; i++) {
 994                         if (bgd[i].free_inodes) {
 995                                 if (has_gdt_chksum)
 996                                         bgd[i].bg_itable_unused =
 997                                                 bgd[i].free_inodes;
 998                                 if (le16_to_cpu(bgd[i].bg_flags) & EXT4_BG_INODE_UNINIT) {
 999                                         int new_flags;
1000                                         put_ext4((uint64_t)le32_to_cpu(bgd[i].inode_id) * fs->blksz,
1001                                                  zero_buffer, fs->blksz);
1002                                         new_flags = le16_to_cpu(bgd[i].bg_flags) & ~EXT4_BG_INODE_UNINIT;
1003                                         bgd[i].bg_flags = cpu_to_le16(new_flags);
1004                                         memcpy(fs->inode_bmaps[i],
1005                                                zero_buffer, fs->blksz);
1006                                 }
1007                                 fs->curr_inode_no =
1008                                     _get_new_inode_no(fs->inode_bmaps[i]);
1009                                 if (fs->curr_inode_no == -1)
1010                                         /* if block bitmap is completely fill */
1011                                         continue;
1012                                 fs->curr_inode_no = fs->curr_inode_no +
1013                                                         (i * inodes_per_grp);
1014                                 fs->first_pass_ibmap++;
1015                                 ext4fs_bg_free_inodes_dec(&bgd[i]);
1016                                 if (has_gdt_chksum)
1017                                         ext4fs_bg_itable_unused_dec(&bgd[i]);
1018                                 ext4fs_sb_free_inodes_dec(fs->sb);
1019                                 status = ext4fs_devread(
1020                                                         (lbaint_t)le32_to_cpu(bgd[i].inode_id) *
1021                                                         fs->sect_perblk, 0,
1022                                                         fs->blksz,
1023                                                         journal_buffer);
1024                                 if (status == 0)
1025                                         goto fail;
1026                                 if (ext4fs_log_journal(journal_buffer,
1027                                                         le32_to_cpu(bgd[i].inode_id)))
1028                                         goto fail;
1029                                 goto success;
1030                         } else
1031                                 debug("no inode left on block group %d\n", i);
1032                 }
1033                 goto fail;
1034         } else {
1035 restart:
1036                 fs->curr_inode_no++;
1037                 /* get the blockbitmap index respective to blockno */
1038                 ibmap_idx = fs->curr_inode_no / inodes_per_grp;
1039                 if (le16_to_cpu(bgd[ibmap_idx].bg_flags) & EXT4_BG_INODE_UNINIT) {
1040                         int new_flags;
1041                         put_ext4((uint64_t)le32_to_cpu(bgd[ibmap_idx].inode_id) * fs->blksz,
1042                                  zero_buffer, fs->blksz);
1043                         new_flags = le16_to_cpu(bgd[ibmap_idx].bg_flags) & ~EXT4_BG_INODE_UNINIT;
1044                         bgd[ibmap_idx].bg_flags = cpu_to_le16(new_flags);
1045                         memcpy(fs->inode_bmaps[ibmap_idx], zero_buffer,
1046                                 fs->blksz);
1047                 }
1048
1049                 if (ext4fs_set_inode_bmap(fs->curr_inode_no,
1050                                           fs->inode_bmaps[ibmap_idx],
1051                                           ibmap_idx) != 0) {
1052                         debug("going for restart for the block no %d %u\n",
1053                               fs->curr_inode_no, ibmap_idx);
1054                         goto restart;
1055                 }
1056
1057                 /* journal backup */
1058                 if (prev_inode_bitmap_index != ibmap_idx) {
1059                         memset(journal_buffer, '\0', fs->blksz);
1060                         status = ext4fs_devread(
1061                                                 (lbaint_t)le32_to_cpu(bgd[ibmap_idx].inode_id)
1062                                                 * fs->sect_perblk,
1063                                                 0, fs->blksz, journal_buffer);
1064                         if (status == 0)
1065                                 goto fail;
1066                         if (ext4fs_log_journal(journal_buffer,
1067                                                 le32_to_cpu(bgd[ibmap_idx].inode_id)))
1068                                 goto fail;
1069                         prev_inode_bitmap_index = ibmap_idx;
1070                 }
1071                 ext4fs_bg_free_inodes_dec(&bgd[ibmap_idx]);
1072                 if (has_gdt_chksum)
1073                         bgd[ibmap_idx].bg_itable_unused =
1074                                         bgd[ibmap_idx].free_inodes;
1075                 ext4fs_sb_free_inodes_dec(fs->sb);
1076                 goto success;
1077         }
1078
1079 success:
1080         free(journal_buffer);
1081         free(zero_buffer);
1082
1083         return fs->curr_inode_no;
1084 fail:
1085         free(journal_buffer);
1086         free(zero_buffer);
1087
1088         return -1;
1089
1090 }
1091
1092
1093 static void alloc_single_indirect_block(struct ext2_inode *file_inode,
1094                                         unsigned int *total_remaining_blocks,
1095                                         unsigned int *no_blks_reqd)
1096 {
1097         short i;
1098         short status;
1099         long int actual_block_no;
1100         long int si_blockno;
1101         /* si :single indirect */
1102         __le32 *si_buffer = NULL;
1103         __le32 *si_start_addr = NULL;
1104         struct ext_filesystem *fs = get_fs();
1105
1106         if (*total_remaining_blocks != 0) {
1107                 si_buffer = zalloc(fs->blksz);
1108                 if (!si_buffer) {
1109                         printf("No Memory\n");
1110                         return;
1111                 }
1112                 si_start_addr = si_buffer;
1113                 si_blockno = ext4fs_get_new_blk_no();
1114                 if (si_blockno == -1) {
1115                         printf("no block left to assign\n");
1116                         goto fail;
1117                 }
1118                 (*no_blks_reqd)++;
1119                 debug("SIPB %ld: %u\n", si_blockno, *total_remaining_blocks);
1120
1121                 status = ext4fs_devread((lbaint_t)si_blockno * fs->sect_perblk,
1122                                         0, fs->blksz, (char *)si_buffer);
1123                 memset(si_buffer, '\0', fs->blksz);
1124                 if (status == 0)
1125                         goto fail;
1126
1127                 for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1128                         actual_block_no = ext4fs_get_new_blk_no();
1129                         if (actual_block_no == -1) {
1130                                 printf("no block left to assign\n");
1131                                 goto fail;
1132                         }
1133                         *si_buffer = cpu_to_le32(actual_block_no);
1134                         debug("SIAB %u: %u\n", *si_buffer,
1135                                 *total_remaining_blocks);
1136
1137                         si_buffer++;
1138                         (*total_remaining_blocks)--;
1139                         if (*total_remaining_blocks == 0)
1140                                 break;
1141                 }
1142
1143                 /* write the block to disk */
1144                 put_ext4(((uint64_t) ((uint64_t)si_blockno * (uint64_t)fs->blksz)),
1145                          si_start_addr, fs->blksz);
1146                 file_inode->b.blocks.indir_block = cpu_to_le32(si_blockno);
1147         }
1148 fail:
1149         free(si_start_addr);
1150 }
1151
1152 static void alloc_double_indirect_block(struct ext2_inode *file_inode,
1153                                         unsigned int *total_remaining_blocks,
1154                                         unsigned int *no_blks_reqd)
1155 {
1156         short i;
1157         short j;
1158         short status;
1159         long int actual_block_no;
1160         /* di:double indirect */
1161         long int di_blockno_parent;
1162         long int di_blockno_child;
1163         __le32 *di_parent_buffer = NULL;
1164         __le32 *di_child_buff = NULL;
1165         __le32 *di_block_start_addr = NULL;
1166         __le32 *di_child_buff_start = NULL;
1167         struct ext_filesystem *fs = get_fs();
1168
1169         if (*total_remaining_blocks != 0) {
1170                 /* double indirect parent block connecting to inode */
1171                 di_blockno_parent = ext4fs_get_new_blk_no();
1172                 if (di_blockno_parent == -1) {
1173                         printf("no block left to assign\n");
1174                         goto fail;
1175                 }
1176                 di_parent_buffer = zalloc(fs->blksz);
1177                 if (!di_parent_buffer)
1178                         goto fail;
1179
1180                 di_block_start_addr = di_parent_buffer;
1181                 (*no_blks_reqd)++;
1182                 debug("DIPB %ld: %u\n", di_blockno_parent,
1183                       *total_remaining_blocks);
1184
1185                 status = ext4fs_devread((lbaint_t)di_blockno_parent *
1186                                         fs->sect_perblk, 0,
1187                                         fs->blksz, (char *)di_parent_buffer);
1188
1189                 if (!status) {
1190                         printf("%s: Device read error!\n", __func__);
1191                         goto fail;
1192                 }
1193                 memset(di_parent_buffer, '\0', fs->blksz);
1194
1195                 /*
1196                  * start:for each double indirect parent
1197                  * block create one more block
1198                  */
1199                 for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1200                         di_blockno_child = ext4fs_get_new_blk_no();
1201                         if (di_blockno_child == -1) {
1202                                 printf("no block left to assign\n");
1203                                 goto fail;
1204                         }
1205                         di_child_buff = zalloc(fs->blksz);
1206                         if (!di_child_buff)
1207                                 goto fail;
1208
1209                         di_child_buff_start = di_child_buff;
1210                         *di_parent_buffer = cpu_to_le32(di_blockno_child);
1211                         di_parent_buffer++;
1212                         (*no_blks_reqd)++;
1213                         debug("DICB %ld: %u\n", di_blockno_child,
1214                               *total_remaining_blocks);
1215
1216                         status = ext4fs_devread((lbaint_t)di_blockno_child *
1217                                                 fs->sect_perblk, 0,
1218                                                 fs->blksz,
1219                                                 (char *)di_child_buff);
1220
1221                         if (!status) {
1222                                 printf("%s: Device read error!\n", __func__);
1223                                 goto fail;
1224                         }
1225                         memset(di_child_buff, '\0', fs->blksz);
1226                         /* filling of actual datablocks for each child */
1227                         for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1228                                 actual_block_no = ext4fs_get_new_blk_no();
1229                                 if (actual_block_no == -1) {
1230                                         printf("no block left to assign\n");
1231                                         goto fail;
1232                                 }
1233                                 *di_child_buff = cpu_to_le32(actual_block_no);
1234                                 debug("DIAB %ld: %u\n", actual_block_no,
1235                                       *total_remaining_blocks);
1236
1237                                 di_child_buff++;
1238                                 (*total_remaining_blocks)--;
1239                                 if (*total_remaining_blocks == 0)
1240                                         break;
1241                         }
1242                         /* write the block  table */
1243                         put_ext4(((uint64_t) ((uint64_t)di_blockno_child * (uint64_t)fs->blksz)),
1244                                  di_child_buff_start, fs->blksz);
1245                         free(di_child_buff_start);
1246                         di_child_buff_start = NULL;
1247
1248                         if (*total_remaining_blocks == 0)
1249                                 break;
1250                 }
1251                 put_ext4(((uint64_t) ((uint64_t)di_blockno_parent * (uint64_t)fs->blksz)),
1252                          di_block_start_addr, fs->blksz);
1253                 file_inode->b.blocks.double_indir_block = cpu_to_le32(di_blockno_parent);
1254         }
1255 fail:
1256         free(di_block_start_addr);
1257 }
1258
1259 static void alloc_triple_indirect_block(struct ext2_inode *file_inode,
1260                                         unsigned int *total_remaining_blocks,
1261                                         unsigned int *no_blks_reqd)
1262 {
1263         short i;
1264         short j;
1265         short k;
1266         long int actual_block_no;
1267         /* ti: Triple Indirect */
1268         long int ti_gp_blockno;
1269         long int ti_parent_blockno;
1270         long int ti_child_blockno;
1271         __le32 *ti_gp_buff = NULL;
1272         __le32 *ti_parent_buff = NULL;
1273         __le32 *ti_child_buff = NULL;
1274         __le32 *ti_gp_buff_start_addr = NULL;
1275         __le32 *ti_pbuff_start_addr = NULL;
1276         __le32 *ti_cbuff_start_addr = NULL;
1277         struct ext_filesystem *fs = get_fs();
1278         if (*total_remaining_blocks != 0) {
1279                 /* triple indirect grand parent block connecting to inode */
1280                 ti_gp_blockno = ext4fs_get_new_blk_no();
1281                 if (ti_gp_blockno == -1) {
1282                         printf("no block left to assign\n");
1283                         return;
1284                 }
1285                 ti_gp_buff = zalloc(fs->blksz);
1286                 if (!ti_gp_buff)
1287                         return;
1288
1289                 ti_gp_buff_start_addr = ti_gp_buff;
1290                 (*no_blks_reqd)++;
1291                 debug("TIGPB %ld: %u\n", ti_gp_blockno,
1292                       *total_remaining_blocks);
1293
1294                 /* for each 4 byte grand parent entry create one more block */
1295                 for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1296                         ti_parent_blockno = ext4fs_get_new_blk_no();
1297                         if (ti_parent_blockno == -1) {
1298                                 printf("no block left to assign\n");
1299                                 goto fail;
1300                         }
1301                         ti_parent_buff = zalloc(fs->blksz);
1302                         if (!ti_parent_buff)
1303                                 goto fail;
1304
1305                         ti_pbuff_start_addr = ti_parent_buff;
1306                         *ti_gp_buff = cpu_to_le32(ti_parent_blockno);
1307                         ti_gp_buff++;
1308                         (*no_blks_reqd)++;
1309                         debug("TIPB %ld: %u\n", ti_parent_blockno,
1310                               *total_remaining_blocks);
1311
1312                         /* for each 4 byte entry parent create one more block */
1313                         for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1314                                 ti_child_blockno = ext4fs_get_new_blk_no();
1315                                 if (ti_child_blockno == -1) {
1316                                         printf("no block left assign\n");
1317                                         goto fail1;
1318                                 }
1319                                 ti_child_buff = zalloc(fs->blksz);
1320                                 if (!ti_child_buff)
1321                                         goto fail1;
1322
1323                                 ti_cbuff_start_addr = ti_child_buff;
1324                                 *ti_parent_buff = cpu_to_le32(ti_child_blockno);
1325                                 ti_parent_buff++;
1326                                 (*no_blks_reqd)++;
1327                                 debug("TICB %ld: %u\n", ti_parent_blockno,
1328                                       *total_remaining_blocks);
1329
1330                                 /* fill actual datablocks for each child */
1331                                 for (k = 0; k < (fs->blksz / sizeof(int));
1332                                         k++) {
1333                                         actual_block_no =
1334                                             ext4fs_get_new_blk_no();
1335                                         if (actual_block_no == -1) {
1336                                                 printf("no block left\n");
1337                                                 free(ti_cbuff_start_addr);
1338                                                 goto fail1;
1339                                         }
1340                                         *ti_child_buff = cpu_to_le32(actual_block_no);
1341                                         debug("TIAB %ld: %u\n", actual_block_no,
1342                                               *total_remaining_blocks);
1343
1344                                         ti_child_buff++;
1345                                         (*total_remaining_blocks)--;
1346                                         if (*total_remaining_blocks == 0)
1347                                                 break;
1348                                 }
1349                                 /* write the child block */
1350                                 put_ext4(((uint64_t) ((uint64_t)ti_child_blockno *
1351                                                       (uint64_t)fs->blksz)),
1352                                          ti_cbuff_start_addr, fs->blksz);
1353                                 free(ti_cbuff_start_addr);
1354
1355                                 if (*total_remaining_blocks == 0)
1356                                         break;
1357                         }
1358                         /* write the parent block */
1359                         put_ext4(((uint64_t) ((uint64_t)ti_parent_blockno * (uint64_t)fs->blksz)),
1360                                  ti_pbuff_start_addr, fs->blksz);
1361                         free(ti_pbuff_start_addr);
1362
1363                         if (*total_remaining_blocks == 0)
1364                                 break;
1365                 }
1366                 /* write the grand parent block */
1367                 put_ext4(((uint64_t) ((uint64_t)ti_gp_blockno * (uint64_t)fs->blksz)),
1368                          ti_gp_buff_start_addr, fs->blksz);
1369                 file_inode->b.blocks.triple_indir_block = cpu_to_le32(ti_gp_blockno);
1370                 free(ti_gp_buff_start_addr);
1371                 return;
1372         }
1373 fail1:
1374         free(ti_pbuff_start_addr);
1375 fail:
1376         free(ti_gp_buff_start_addr);
1377 }
1378
1379 void ext4fs_allocate_blocks(struct ext2_inode *file_inode,
1380                                 unsigned int total_remaining_blocks,
1381                                 unsigned int *total_no_of_block)
1382 {
1383         short i;
1384         long int direct_blockno;
1385         unsigned int no_blks_reqd = 0;
1386
1387         /* allocation of direct blocks */
1388         for (i = 0; total_remaining_blocks && i < INDIRECT_BLOCKS; i++) {
1389                 direct_blockno = ext4fs_get_new_blk_no();
1390                 if (direct_blockno == -1) {
1391                         printf("no block left to assign\n");
1392                         return;
1393                 }
1394                 file_inode->b.blocks.dir_blocks[i] = cpu_to_le32(direct_blockno);
1395                 debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks);
1396
1397                 total_remaining_blocks--;
1398         }
1399
1400         alloc_single_indirect_block(file_inode, &total_remaining_blocks,
1401                                     &no_blks_reqd);
1402         alloc_double_indirect_block(file_inode, &total_remaining_blocks,
1403                                     &no_blks_reqd);
1404         alloc_triple_indirect_block(file_inode, &total_remaining_blocks,
1405                                     &no_blks_reqd);
1406         *total_no_of_block += no_blks_reqd;
1407 }
1408
1409 #endif
1410
1411 static struct ext4_extent_header *ext4fs_get_extent_block
1412         (struct ext2_data *data, char *buf,
1413                 struct ext4_extent_header *ext_block,
1414                 uint32_t fileblock, int log2_blksz)
1415 {
1416         struct ext4_extent_idx *index;
1417         unsigned long long block;
1418         int blksz = EXT2_BLOCK_SIZE(data);
1419         int i;
1420
1421         while (1) {
1422                 index = (struct ext4_extent_idx *)(ext_block + 1);
1423
1424                 if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
1425                         return NULL;
1426
1427                 if (ext_block->eh_depth == 0)
1428                         return ext_block;
1429                 i = -1;
1430                 do {
1431                         i++;
1432                         if (i >= le16_to_cpu(ext_block->eh_entries))
1433                                 break;
1434                 } while (fileblock >= le32_to_cpu(index[i].ei_block));
1435
1436                 if (--i < 0)
1437                         return NULL;
1438
1439                 block = le16_to_cpu(index[i].ei_leaf_hi);
1440                 block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
1441
1442                 if (ext4fs_devread((lbaint_t)block << log2_blksz, 0, blksz,
1443                                    buf))
1444                         ext_block = (struct ext4_extent_header *)buf;
1445                 else
1446                         return NULL;
1447         }
1448 }
1449
1450 static int ext4fs_blockgroup
1451         (struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
1452 {
1453         long int blkno;
1454         unsigned int blkoff, desc_per_blk;
1455         int log2blksz = get_fs()->dev_desc->log2blksz;
1456
1457         desc_per_blk = EXT2_BLOCK_SIZE(data) / sizeof(struct ext2_block_group);
1458
1459         blkno = le32_to_cpu(data->sblock.first_data_block) + 1 +
1460                         group / desc_per_blk;
1461         blkoff = (group % desc_per_blk) * sizeof(struct ext2_block_group);
1462
1463         debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n",
1464               group, blkno, blkoff);
1465
1466         return ext4fs_devread((lbaint_t)blkno <<
1467                               (LOG2_BLOCK_SIZE(data) - log2blksz),
1468                               blkoff, sizeof(struct ext2_block_group),
1469                               (char *)blkgrp);
1470 }
1471
1472 int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
1473 {
1474         struct ext2_block_group blkgrp;
1475         struct ext2_sblock *sblock = &data->sblock;
1476         struct ext_filesystem *fs = get_fs();
1477         int log2blksz = get_fs()->dev_desc->log2blksz;
1478         int inodes_per_block, status;
1479         long int blkno;
1480         unsigned int blkoff;
1481
1482         /* It is easier to calculate if the first inode is 0. */
1483         ino--;
1484         status = ext4fs_blockgroup(data, ino / le32_to_cpu
1485                                    (sblock->inodes_per_group), &blkgrp);
1486         if (status == 0)
1487                 return 0;
1488
1489         inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
1490         blkno = le32_to_cpu(blkgrp.inode_table_id) +
1491             (ino % le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
1492         blkoff = (ino % inodes_per_block) * fs->inodesz;
1493         /* Read the inode. */
1494         status = ext4fs_devread((lbaint_t)blkno << (LOG2_BLOCK_SIZE(data) -
1495                                 log2blksz), blkoff,
1496                                 sizeof(struct ext2_inode), (char *)inode);
1497         if (status == 0)
1498                 return 0;
1499
1500         return 1;
1501 }
1502
1503 long int read_allocated_block(struct ext2_inode *inode, int fileblock)
1504 {
1505         long int blknr;
1506         int blksz;
1507         int log2_blksz;
1508         int status;
1509         long int rblock;
1510         long int perblock_parent;
1511         long int perblock_child;
1512         unsigned long long start;
1513         /* get the blocksize of the filesystem */
1514         blksz = EXT2_BLOCK_SIZE(ext4fs_root);
1515         log2_blksz = LOG2_BLOCK_SIZE(ext4fs_root)
1516                 - get_fs()->dev_desc->log2blksz;
1517
1518         if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
1519                 char *buf = zalloc(blksz);
1520                 if (!buf)
1521                         return -ENOMEM;
1522                 struct ext4_extent_header *ext_block;
1523                 struct ext4_extent *extent;
1524                 int i = -1;
1525                 ext_block =
1526                         ext4fs_get_extent_block(ext4fs_root, buf,
1527                                                 (struct ext4_extent_header *)
1528                                                 inode->b.blocks.dir_blocks,
1529                                                 fileblock, log2_blksz);
1530                 if (!ext_block) {
1531                         printf("invalid extent block\n");
1532                         free(buf);
1533                         return -EINVAL;
1534                 }
1535
1536                 extent = (struct ext4_extent *)(ext_block + 1);
1537
1538                 do {
1539                         i++;
1540                         if (i >= le16_to_cpu(ext_block->eh_entries))
1541                                 break;
1542                 } while (fileblock >= le32_to_cpu(extent[i].ee_block));
1543                 if (--i >= 0) {
1544                         fileblock -= le32_to_cpu(extent[i].ee_block);
1545                         if (fileblock >= le16_to_cpu(extent[i].ee_len)) {
1546                                 free(buf);
1547                                 return 0;
1548                         }
1549
1550                         start = le16_to_cpu(extent[i].ee_start_hi);
1551                         start = (start << 32) +
1552                                         le32_to_cpu(extent[i].ee_start_lo);
1553                         free(buf);
1554                         return fileblock + start;
1555                 }
1556
1557                 printf("Extent Error\n");
1558                 free(buf);
1559                 return -1;
1560         }
1561
1562         /* Direct blocks. */
1563         if (fileblock < INDIRECT_BLOCKS)
1564                 blknr = le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);
1565
1566         /* Indirect. */
1567         else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
1568                 if (ext4fs_indir1_block == NULL) {
1569                         ext4fs_indir1_block = zalloc(blksz);
1570                         if (ext4fs_indir1_block == NULL) {
1571                                 printf("** SI ext2fs read block (indir 1)"
1572                                         "malloc failed. **\n");
1573                                 return -1;
1574                         }
1575                         ext4fs_indir1_size = blksz;
1576                         ext4fs_indir1_blkno = -1;
1577                 }
1578                 if (blksz != ext4fs_indir1_size) {
1579                         free(ext4fs_indir1_block);
1580                         ext4fs_indir1_block = NULL;
1581                         ext4fs_indir1_size = 0;
1582                         ext4fs_indir1_blkno = -1;
1583                         ext4fs_indir1_block = zalloc(blksz);
1584                         if (ext4fs_indir1_block == NULL) {
1585                                 printf("** SI ext2fs read block (indir 1):"
1586                                         "malloc failed. **\n");
1587                                 return -1;
1588                         }
1589                         ext4fs_indir1_size = blksz;
1590                 }
1591                 if ((le32_to_cpu(inode->b.blocks.indir_block) <<
1592                      log2_blksz) != ext4fs_indir1_blkno) {
1593                         status =
1594                             ext4fs_devread((lbaint_t)le32_to_cpu
1595                                            (inode->b.blocks.
1596                                             indir_block) << log2_blksz, 0,
1597                                            blksz, (char *)ext4fs_indir1_block);
1598                         if (status == 0) {
1599                                 printf("** SI ext2fs read block (indir 1)"
1600                                         "failed. **\n");
1601                                 return 0;
1602                         }
1603                         ext4fs_indir1_blkno =
1604                                 le32_to_cpu(inode->b.blocks.
1605                                                indir_block) << log2_blksz;
1606                 }
1607                 blknr = le32_to_cpu(ext4fs_indir1_block
1608                                       [fileblock - INDIRECT_BLOCKS]);
1609         }
1610         /* Double indirect. */
1611         else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 *
1612                                         (blksz / 4 + 1)))) {
1613
1614                 long int perblock = blksz / 4;
1615                 long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4);
1616
1617                 if (ext4fs_indir1_block == NULL) {
1618                         ext4fs_indir1_block = zalloc(blksz);
1619                         if (ext4fs_indir1_block == NULL) {
1620                                 printf("** DI ext2fs read block (indir 2 1)"
1621                                         "malloc failed. **\n");
1622                                 return -1;
1623                         }
1624                         ext4fs_indir1_size = blksz;
1625                         ext4fs_indir1_blkno = -1;
1626                 }
1627                 if (blksz != ext4fs_indir1_size) {
1628                         free(ext4fs_indir1_block);
1629                         ext4fs_indir1_block = NULL;
1630                         ext4fs_indir1_size = 0;
1631                         ext4fs_indir1_blkno = -1;
1632                         ext4fs_indir1_block = zalloc(blksz);
1633                         if (ext4fs_indir1_block == NULL) {
1634                                 printf("** DI ext2fs read block (indir 2 1)"
1635                                         "malloc failed. **\n");
1636                                 return -1;
1637                         }
1638                         ext4fs_indir1_size = blksz;
1639                 }
1640                 if ((le32_to_cpu(inode->b.blocks.double_indir_block) <<
1641                      log2_blksz) != ext4fs_indir1_blkno) {
1642                         status =
1643                             ext4fs_devread((lbaint_t)le32_to_cpu
1644                                            (inode->b.blocks.
1645                                             double_indir_block) << log2_blksz,
1646                                            0, blksz,
1647                                            (char *)ext4fs_indir1_block);
1648                         if (status == 0) {
1649                                 printf("** DI ext2fs read block (indir 2 1)"
1650                                         "failed. **\n");
1651                                 return -1;
1652                         }
1653                         ext4fs_indir1_blkno =
1654                             le32_to_cpu(inode->b.blocks.double_indir_block) <<
1655                             log2_blksz;
1656                 }
1657
1658                 if (ext4fs_indir2_block == NULL) {
1659                         ext4fs_indir2_block = zalloc(blksz);
1660                         if (ext4fs_indir2_block == NULL) {
1661                                 printf("** DI ext2fs read block (indir 2 2)"
1662                                         "malloc failed. **\n");
1663                                 return -1;
1664                         }
1665                         ext4fs_indir2_size = blksz;
1666                         ext4fs_indir2_blkno = -1;
1667                 }
1668                 if (blksz != ext4fs_indir2_size) {
1669                         free(ext4fs_indir2_block);
1670                         ext4fs_indir2_block = NULL;
1671                         ext4fs_indir2_size = 0;
1672                         ext4fs_indir2_blkno = -1;
1673                         ext4fs_indir2_block = zalloc(blksz);
1674                         if (ext4fs_indir2_block == NULL) {
1675                                 printf("** DI ext2fs read block (indir 2 2)"
1676                                         "malloc failed. **\n");
1677                                 return -1;
1678                         }
1679                         ext4fs_indir2_size = blksz;
1680                 }
1681                 if ((le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) <<
1682                      log2_blksz) != ext4fs_indir2_blkno) {
1683                         status = ext4fs_devread((lbaint_t)le32_to_cpu
1684                                                 (ext4fs_indir1_block
1685                                                  [rblock /
1686                                                   perblock]) << log2_blksz, 0,
1687                                                 blksz,
1688                                                 (char *)ext4fs_indir2_block);
1689                         if (status == 0) {
1690                                 printf("** DI ext2fs read block (indir 2 2)"
1691                                         "failed. **\n");
1692                                 return -1;
1693                         }
1694                         ext4fs_indir2_blkno =
1695                             le32_to_cpu(ext4fs_indir1_block[rblock
1696                                                               /
1697                                                               perblock]) <<
1698                             log2_blksz;
1699                 }
1700                 blknr = le32_to_cpu(ext4fs_indir2_block[rblock % perblock]);
1701         }
1702         /* Tripple indirect. */
1703         else {
1704                 rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 +
1705                                       (blksz / 4 * blksz / 4));
1706                 perblock_child = blksz / 4;
1707                 perblock_parent = ((blksz / 4) * (blksz / 4));
1708
1709                 if (ext4fs_indir1_block == NULL) {
1710                         ext4fs_indir1_block = zalloc(blksz);
1711                         if (ext4fs_indir1_block == NULL) {
1712                                 printf("** TI ext2fs read block (indir 2 1)"
1713                                         "malloc failed. **\n");
1714                                 return -1;
1715                         }
1716                         ext4fs_indir1_size = blksz;
1717                         ext4fs_indir1_blkno = -1;
1718                 }
1719                 if (blksz != ext4fs_indir1_size) {
1720                         free(ext4fs_indir1_block);
1721                         ext4fs_indir1_block = NULL;
1722                         ext4fs_indir1_size = 0;
1723                         ext4fs_indir1_blkno = -1;
1724                         ext4fs_indir1_block = zalloc(blksz);
1725                         if (ext4fs_indir1_block == NULL) {
1726                                 printf("** TI ext2fs read block (indir 2 1)"
1727                                         "malloc failed. **\n");
1728                                 return -1;
1729                         }
1730                         ext4fs_indir1_size = blksz;
1731                 }
1732                 if ((le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1733                      log2_blksz) != ext4fs_indir1_blkno) {
1734                         status = ext4fs_devread
1735                             ((lbaint_t)
1736                              le32_to_cpu(inode->b.blocks.triple_indir_block)
1737                              << log2_blksz, 0, blksz,
1738                              (char *)ext4fs_indir1_block);
1739                         if (status == 0) {
1740                                 printf("** TI ext2fs read block (indir 2 1)"
1741                                         "failed. **\n");
1742                                 return -1;
1743                         }
1744                         ext4fs_indir1_blkno =
1745                             le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1746                             log2_blksz;
1747                 }
1748
1749                 if (ext4fs_indir2_block == NULL) {
1750                         ext4fs_indir2_block = zalloc(blksz);
1751                         if (ext4fs_indir2_block == NULL) {
1752                                 printf("** TI ext2fs read block (indir 2 2)"
1753                                         "malloc failed. **\n");
1754                                 return -1;
1755                         }
1756                         ext4fs_indir2_size = blksz;
1757                         ext4fs_indir2_blkno = -1;
1758                 }
1759                 if (blksz != ext4fs_indir2_size) {
1760                         free(ext4fs_indir2_block);
1761                         ext4fs_indir2_block = NULL;
1762                         ext4fs_indir2_size = 0;
1763                         ext4fs_indir2_blkno = -1;
1764                         ext4fs_indir2_block = zalloc(blksz);
1765                         if (ext4fs_indir2_block == NULL) {
1766                                 printf("** TI ext2fs read block (indir 2 2)"
1767                                         "malloc failed. **\n");
1768                                 return -1;
1769                         }
1770                         ext4fs_indir2_size = blksz;
1771                 }
1772                 if ((le32_to_cpu(ext4fs_indir1_block[rblock /
1773                                                        perblock_parent]) <<
1774                      log2_blksz)
1775                     != ext4fs_indir2_blkno) {
1776                         status = ext4fs_devread((lbaint_t)le32_to_cpu
1777                                                 (ext4fs_indir1_block
1778                                                  [rblock /
1779                                                   perblock_parent]) <<
1780                                                 log2_blksz, 0, blksz,
1781                                                 (char *)ext4fs_indir2_block);
1782                         if (status == 0) {
1783                                 printf("** TI ext2fs read block (indir 2 2)"
1784                                         "failed. **\n");
1785                                 return -1;
1786                         }
1787                         ext4fs_indir2_blkno =
1788                             le32_to_cpu(ext4fs_indir1_block[rblock /
1789                                                               perblock_parent])
1790                             << log2_blksz;
1791                 }
1792
1793                 if (ext4fs_indir3_block == NULL) {
1794                         ext4fs_indir3_block = zalloc(blksz);
1795                         if (ext4fs_indir3_block == NULL) {
1796                                 printf("** TI ext2fs read block (indir 2 2)"
1797                                         "malloc failed. **\n");
1798                                 return -1;
1799                         }
1800                         ext4fs_indir3_size = blksz;
1801                         ext4fs_indir3_blkno = -1;
1802                 }
1803                 if (blksz != ext4fs_indir3_size) {
1804                         free(ext4fs_indir3_block);
1805                         ext4fs_indir3_block = NULL;
1806                         ext4fs_indir3_size = 0;
1807                         ext4fs_indir3_blkno = -1;
1808                         ext4fs_indir3_block = zalloc(blksz);
1809                         if (ext4fs_indir3_block == NULL) {
1810                                 printf("** TI ext2fs read block (indir 2 2)"
1811                                         "malloc failed. **\n");
1812                                 return -1;
1813                         }
1814                         ext4fs_indir3_size = blksz;
1815                 }
1816                 if ((le32_to_cpu(ext4fs_indir2_block[rblock
1817                                                        /
1818                                                        perblock_child]) <<
1819                      log2_blksz) != ext4fs_indir3_blkno) {
1820                         status =
1821                             ext4fs_devread((lbaint_t)le32_to_cpu
1822                                            (ext4fs_indir2_block
1823                                             [(rblock / perblock_child)
1824                                              % (blksz / 4)]) << log2_blksz, 0,
1825                                            blksz, (char *)ext4fs_indir3_block);
1826                         if (status == 0) {
1827                                 printf("** TI ext2fs read block (indir 2 2)"
1828                                        "failed. **\n");
1829                                 return -1;
1830                         }
1831                         ext4fs_indir3_blkno =
1832                             le32_to_cpu(ext4fs_indir2_block[(rblock /
1833                                                                perblock_child) %
1834                                                               (blksz /
1835                                                                4)]) <<
1836                             log2_blksz;
1837                 }
1838
1839                 blknr = le32_to_cpu(ext4fs_indir3_block
1840                                       [rblock % perblock_child]);
1841         }
1842         debug("read_allocated_block %ld\n", blknr);
1843
1844         return blknr;
1845 }
1846
1847 /**
1848  * ext4fs_reinit_global() - Reinitialize values of ext4 write implementation's
1849  *                          global pointers
1850  *
1851  * This function assures that for a file with the same name but different size
1852  * the sequential store on the ext4 filesystem will be correct.
1853  *
1854  * In this function the global data, responsible for internal representation
1855  * of the ext4 data are initialized to the reset state. Without this, during
1856  * replacement of the smaller file with the bigger truncation of new file was
1857  * performed.
1858  */
1859 void ext4fs_reinit_global(void)
1860 {
1861         if (ext4fs_indir1_block != NULL) {
1862                 free(ext4fs_indir1_block);
1863                 ext4fs_indir1_block = NULL;
1864                 ext4fs_indir1_size = 0;
1865                 ext4fs_indir1_blkno = -1;
1866         }
1867         if (ext4fs_indir2_block != NULL) {
1868                 free(ext4fs_indir2_block);
1869                 ext4fs_indir2_block = NULL;
1870                 ext4fs_indir2_size = 0;
1871                 ext4fs_indir2_blkno = -1;
1872         }
1873         if (ext4fs_indir3_block != NULL) {
1874                 free(ext4fs_indir3_block);
1875                 ext4fs_indir3_block = NULL;
1876                 ext4fs_indir3_size = 0;
1877                 ext4fs_indir3_blkno = -1;
1878         }
1879 }
1880 void ext4fs_close(void)
1881 {
1882         if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) {
1883                 ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen);
1884                 ext4fs_file = NULL;
1885         }
1886         if (ext4fs_root != NULL) {
1887                 free(ext4fs_root);
1888                 ext4fs_root = NULL;
1889         }
1890
1891         ext4fs_reinit_global();
1892 }
1893
1894 int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
1895                                 struct ext2fs_node **fnode, int *ftype)
1896 {
1897         unsigned int fpos = 0;
1898         int status;
1899         loff_t actread;
1900         struct ext2fs_node *diro = (struct ext2fs_node *) dir;
1901
1902 #ifdef DEBUG
1903         if (name != NULL)
1904                 printf("Iterate dir %s\n", name);
1905 #endif /* of DEBUG */
1906         if (!diro->inode_read) {
1907                 status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
1908                 if (status == 0)
1909                         return 0;
1910         }
1911         /* Search the file.  */
1912         while (fpos < le32_to_cpu(diro->inode.size)) {
1913                 struct ext2_dirent dirent;
1914
1915                 status = ext4fs_read_file(diro, fpos,
1916                                            sizeof(struct ext2_dirent),
1917                                            (char *)&dirent, &actread);
1918                 if (status < 0)
1919                         return 0;
1920
1921                 if (dirent.direntlen == 0) {
1922                         printf("Failed to iterate over directory %s\n", name);
1923                         return 0;
1924                 }
1925
1926                 if (dirent.namelen != 0) {
1927                         char filename[dirent.namelen + 1];
1928                         struct ext2fs_node *fdiro;
1929                         int type = FILETYPE_UNKNOWN;
1930
1931                         status = ext4fs_read_file(diro,
1932                                                   fpos +
1933                                                   sizeof(struct ext2_dirent),
1934                                                   dirent.namelen, filename,
1935                                                   &actread);
1936                         if (status < 0)
1937                                 return 0;
1938
1939                         fdiro = zalloc(sizeof(struct ext2fs_node));
1940                         if (!fdiro)
1941                                 return 0;
1942
1943                         fdiro->data = diro->data;
1944                         fdiro->ino = le32_to_cpu(dirent.inode);
1945
1946                         filename[dirent.namelen] = '\0';
1947
1948                         if (dirent.filetype != FILETYPE_UNKNOWN) {
1949                                 fdiro->inode_read = 0;
1950
1951                                 if (dirent.filetype == FILETYPE_DIRECTORY)
1952                                         type = FILETYPE_DIRECTORY;
1953                                 else if (dirent.filetype == FILETYPE_SYMLINK)
1954                                         type = FILETYPE_SYMLINK;
1955                                 else if (dirent.filetype == FILETYPE_REG)
1956                                         type = FILETYPE_REG;
1957                         } else {
1958                                 status = ext4fs_read_inode(diro->data,
1959                                                            le32_to_cpu
1960                                                            (dirent.inode),
1961                                                            &fdiro->inode);
1962                                 if (status == 0) {
1963                                         free(fdiro);
1964                                         return 0;
1965                                 }
1966                                 fdiro->inode_read = 1;
1967
1968                                 if ((le16_to_cpu(fdiro->inode.mode) &
1969                                      FILETYPE_INO_MASK) ==
1970                                     FILETYPE_INO_DIRECTORY) {
1971                                         type = FILETYPE_DIRECTORY;
1972                                 } else if ((le16_to_cpu(fdiro->inode.mode)
1973                                             & FILETYPE_INO_MASK) ==
1974                                            FILETYPE_INO_SYMLINK) {
1975                                         type = FILETYPE_SYMLINK;
1976                                 } else if ((le16_to_cpu(fdiro->inode.mode)
1977                                             & FILETYPE_INO_MASK) ==
1978                                            FILETYPE_INO_REG) {
1979                                         type = FILETYPE_REG;
1980                                 }
1981                         }
1982 #ifdef DEBUG
1983                         printf("iterate >%s<\n", filename);
1984 #endif /* of DEBUG */
1985                         if ((name != NULL) && (fnode != NULL)
1986                             && (ftype != NULL)) {
1987                                 if (strcmp(filename, name) == 0) {
1988                                         *ftype = type;
1989                                         *fnode = fdiro;
1990                                         return 1;
1991                                 }
1992                         } else {
1993                                 if (fdiro->inode_read == 0) {
1994                                         status = ext4fs_read_inode(diro->data,
1995                                                                  le32_to_cpu(
1996                                                                  dirent.inode),
1997                                                                  &fdiro->inode);
1998                                         if (status == 0) {
1999                                                 free(fdiro);
2000                                                 return 0;
2001                                         }
2002                                         fdiro->inode_read = 1;
2003                                 }
2004                                 switch (type) {
2005                                 case FILETYPE_DIRECTORY:
2006                                         printf("<DIR> ");
2007                                         break;
2008                                 case FILETYPE_SYMLINK:
2009                                         printf("<SYM> ");
2010                                         break;
2011                                 case FILETYPE_REG:
2012                                         printf("      ");
2013                                         break;
2014                                 default:
2015                                         printf("< ? > ");
2016                                         break;
2017                                 }
2018                                 printf("%10u %s\n",
2019                                        le32_to_cpu(fdiro->inode.size),
2020                                         filename);
2021                         }
2022                         free(fdiro);
2023                 }
2024                 fpos += le16_to_cpu(dirent.direntlen);
2025         }
2026         return 0;
2027 }
2028
2029 static char *ext4fs_read_symlink(struct ext2fs_node *node)
2030 {
2031         char *symlink;
2032         struct ext2fs_node *diro = node;
2033         int status;
2034         loff_t actread;
2035
2036         if (!diro->inode_read) {
2037                 status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2038                 if (status == 0)
2039                         return NULL;
2040         }
2041         symlink = zalloc(le32_to_cpu(diro->inode.size) + 1);
2042         if (!symlink)
2043                 return NULL;
2044
2045         if (le32_to_cpu(diro->inode.size) < sizeof(diro->inode.b.symlink)) {
2046                 strncpy(symlink, diro->inode.b.symlink,
2047                          le32_to_cpu(diro->inode.size));
2048         } else {
2049                 status = ext4fs_read_file(diro, 0,
2050                                            le32_to_cpu(diro->inode.size),
2051                                            symlink, &actread);
2052                 if ((status < 0) || (actread == 0)) {
2053                         free(symlink);
2054                         return NULL;
2055                 }
2056         }
2057         symlink[le32_to_cpu(diro->inode.size)] = '\0';
2058         return symlink;
2059 }
2060
2061 static int ext4fs_find_file1(const char *currpath,
2062                              struct ext2fs_node *currroot,
2063                              struct ext2fs_node **currfound, int *foundtype)
2064 {
2065         char fpath[strlen(currpath) + 1];
2066         char *name = fpath;
2067         char *next;
2068         int status;
2069         int type = FILETYPE_DIRECTORY;
2070         struct ext2fs_node *currnode = currroot;
2071         struct ext2fs_node *oldnode = currroot;
2072
2073         strncpy(fpath, currpath, strlen(currpath) + 1);
2074
2075         /* Remove all leading slashes. */
2076         while (*name == '/')
2077                 name++;
2078
2079         if (!*name) {
2080                 *currfound = currnode;
2081                 return 1;
2082         }
2083
2084         for (;;) {
2085                 int found;
2086
2087                 /* Extract the actual part from the pathname. */
2088                 next = strchr(name, '/');
2089                 if (next) {
2090                         /* Remove all leading slashes. */
2091                         while (*next == '/')
2092                                 *(next++) = '\0';
2093                 }
2094
2095                 if (type != FILETYPE_DIRECTORY) {
2096                         ext4fs_free_node(currnode, currroot);
2097                         return 0;
2098                 }
2099
2100                 oldnode = currnode;
2101
2102                 /* Iterate over the directory. */
2103                 found = ext4fs_iterate_dir(currnode, name, &currnode, &type);
2104                 if (found == 0)
2105                         return 0;
2106
2107                 if (found == -1)
2108                         break;
2109
2110                 /* Read in the symlink and follow it. */
2111                 if (type == FILETYPE_SYMLINK) {
2112                         char *symlink;
2113
2114                         /* Test if the symlink does not loop. */
2115                         if (++symlinknest == 8) {
2116                                 ext4fs_free_node(currnode, currroot);
2117                                 ext4fs_free_node(oldnode, currroot);
2118                                 return 0;
2119                         }
2120
2121                         symlink = ext4fs_read_symlink(currnode);
2122                         ext4fs_free_node(currnode, currroot);
2123
2124                         if (!symlink) {
2125                                 ext4fs_free_node(oldnode, currroot);
2126                                 return 0;
2127                         }
2128
2129                         debug("Got symlink >%s<\n", symlink);
2130
2131                         if (symlink[0] == '/') {
2132                                 ext4fs_free_node(oldnode, currroot);
2133                                 oldnode = &ext4fs_root->diropen;
2134                         }
2135
2136                         /* Lookup the node the symlink points to. */
2137                         status = ext4fs_find_file1(symlink, oldnode,
2138                                                     &currnode, &type);
2139
2140                         free(symlink);
2141
2142                         if (status == 0) {
2143                                 ext4fs_free_node(oldnode, currroot);
2144                                 return 0;
2145                         }
2146                 }
2147
2148                 ext4fs_free_node(oldnode, currroot);
2149
2150                 /* Found the node! */
2151                 if (!next || *next == '\0') {
2152                         *currfound = currnode;
2153                         *foundtype = type;
2154                         return 1;
2155                 }
2156                 name = next;
2157         }
2158         return -1;
2159 }
2160
2161 int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
2162         struct ext2fs_node **foundnode, int expecttype)
2163 {
2164         int status;
2165         int foundtype = FILETYPE_DIRECTORY;
2166
2167         symlinknest = 0;
2168         if (!path)
2169                 return 0;
2170
2171         status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype);
2172         if (status == 0)
2173                 return 0;
2174
2175         /* Check if the node that was found was of the expected type. */
2176         if ((expecttype == FILETYPE_REG) && (foundtype != expecttype))
2177                 return 0;
2178         else if ((expecttype == FILETYPE_DIRECTORY)
2179                    && (foundtype != expecttype))
2180                 return 0;
2181
2182         return 1;
2183 }
2184
2185 int ext4fs_open(const char *filename, loff_t *len)
2186 {
2187         struct ext2fs_node *fdiro = NULL;
2188         int status;
2189
2190         if (ext4fs_root == NULL)
2191                 return -1;
2192
2193         ext4fs_file = NULL;
2194         status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro,
2195                                   FILETYPE_REG);
2196         if (status == 0)
2197                 goto fail;
2198
2199         if (!fdiro->inode_read) {
2200                 status = ext4fs_read_inode(fdiro->data, fdiro->ino,
2201                                 &fdiro->inode);
2202                 if (status == 0)
2203                         goto fail;
2204         }
2205         *len = le32_to_cpu(fdiro->inode.size);
2206         ext4fs_file = fdiro;
2207
2208         return 0;
2209 fail:
2210         ext4fs_free_node(fdiro, &ext4fs_root->diropen);
2211
2212         return -1;
2213 }
2214
2215 int ext4fs_mount(unsigned part_length)
2216 {
2217         struct ext2_data *data;
2218         int status;
2219         struct ext_filesystem *fs = get_fs();
2220         data = zalloc(SUPERBLOCK_SIZE);
2221         if (!data)
2222                 return 0;
2223
2224         /* Read the superblock. */
2225         status = ext4_read_superblock((char *)&data->sblock);
2226
2227         if (status == 0)
2228                 goto fail;
2229
2230         /* Make sure this is an ext2 filesystem. */
2231         if (le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
2232                 goto fail;
2233
2234         /*
2235          * The 64bit feature was enabled when metadata_csum was enabled
2236          * and we do not support metadata_csum (and cannot reliably find
2237          * files when it is set.  Refuse to mount.
2238          */
2239         if (le32_to_cpu(data->sblock.feature_incompat) & EXT4_FEATURE_INCOMPAT_64BIT) {
2240                 printf("Unsupported feature found (64bit, possibly metadata_csum), not mounting\n");
2241                 goto fail;
2242         }
2243
2244         if (le32_to_cpu(data->sblock.revision_level) == 0)
2245                 fs->inodesz = 128;
2246         else
2247                 fs->inodesz = le16_to_cpu(data->sblock.inode_size);
2248
2249         debug("EXT2 rev %d, inode_size %d\n",
2250                le32_to_cpu(data->sblock.revision_level), fs->inodesz);
2251
2252         data->diropen.data = data;
2253         data->diropen.ino = 2;
2254         data->diropen.inode_read = 1;
2255         data->inode = &data->diropen.inode;
2256
2257         status = ext4fs_read_inode(data, 2, data->inode);
2258         if (status == 0)
2259                 goto fail;
2260
2261         ext4fs_root = data;
2262
2263         return 1;
2264 fail:
2265         printf("Failed to mount ext2 filesystem...\n");
2266         free(data);
2267         ext4fs_root = NULL;
2268
2269         return 0;
2270 }