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 <malloc.h> 26 #include <stddef.h> 27 #include <linux/stat.h> 28 #include <linux/time.h> 29 #include <asm/byteorder.h> 30 #include "ext4_common.h" 31 32 struct ext2_data *ext4fs_root; 33 struct ext2fs_node *ext4fs_file; 34 uint32_t *ext4fs_indir1_block; 35 int ext4fs_indir1_size; 36 int ext4fs_indir1_blkno = -1; 37 uint32_t *ext4fs_indir2_block; 38 int ext4fs_indir2_size; 39 int ext4fs_indir2_blkno = -1; 40 41 uint32_t *ext4fs_indir3_block; 42 int ext4fs_indir3_size; 43 int ext4fs_indir3_blkno = -1; 44 struct ext2_inode *g_parent_inode; 45 static int symlinknest; 46 47 #if defined(CONFIG_EXT4_WRITE) 48 uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n) 49 { 50 uint32_t res = size / n; 51 if (res * n != size) 52 res++; 53 54 return res; 55 } 56 57 void put_ext4(uint64_t off, void *buf, uint32_t size) 58 { 59 uint64_t startblock; 60 uint64_t remainder; 61 unsigned char *temp_ptr = NULL; 62 struct ext_filesystem *fs = get_fs(); 63 int log2blksz = fs->dev_desc->log2blksz; 64 ALLOC_CACHE_ALIGN_BUFFER(unsigned char, sec_buf, fs->dev_desc->blksz); 65 66 startblock = off >> log2blksz; 67 startblock += part_offset; 68 remainder = off & (uint64_t)(fs->dev_desc->blksz - 1); 69 70 if (fs->dev_desc == NULL) 71 return; 72 73 if ((startblock + (size >> log2blksz)) > 74 (part_offset + fs->total_sect)) { 75 printf("part_offset is " LBAFU "\n", part_offset); 76 printf("total_sector is %llu\n", fs->total_sect); 77 printf("error: overflow occurs\n"); 78 return; 79 } 80 81 if (remainder) { 82 if (fs->dev_desc->block_read) { 83 fs->dev_desc->block_read(fs->dev_desc->dev, 84 startblock, 1, sec_buf); 85 temp_ptr = sec_buf; 86 memcpy((temp_ptr + remainder), 87 (unsigned char *)buf, size); 88 fs->dev_desc->block_write(fs->dev_desc->dev, 89 startblock, 1, sec_buf); 90 } 91 } else { 92 if (size >> log2blksz != 0) { 93 fs->dev_desc->block_write(fs->dev_desc->dev, 94 startblock, 95 size >> log2blksz, 96 (unsigned long *)buf); 97 } else { 98 fs->dev_desc->block_read(fs->dev_desc->dev, 99 startblock, 1, sec_buf); 100 temp_ptr = sec_buf; 101 memcpy(temp_ptr, buf, size); 102 fs->dev_desc->block_write(fs->dev_desc->dev, 103 startblock, 1, 104 (unsigned long *)sec_buf); 105 } 106 } 107 } 108 109 static int _get_new_inode_no(unsigned char *buffer) 110 { 111 struct ext_filesystem *fs = get_fs(); 112 unsigned char input; 113 int operand, status; 114 int count = 1; 115 int j = 0; 116 117 /* get the blocksize of the filesystem */ 118 unsigned char *ptr = buffer; 119 while (*ptr == 255) { 120 ptr++; 121 count += 8; 122 if (count > ext4fs_root->sblock.inodes_per_group) 123 return -1; 124 } 125 126 for (j = 0; j < fs->blksz; j++) { 127 input = *ptr; 128 int i = 0; 129 while (i <= 7) { 130 operand = 1 << i; 131 status = input & operand; 132 if (status) { 133 i++; 134 count++; 135 } else { 136 *ptr |= operand; 137 return count; 138 } 139 } 140 ptr = ptr + 1; 141 } 142 143 return -1; 144 } 145 146 static int _get_new_blk_no(unsigned char *buffer) 147 { 148 unsigned char input; 149 int operand, status; 150 int count = 0; 151 int j = 0; 152 unsigned char *ptr = buffer; 153 struct ext_filesystem *fs = get_fs(); 154 155 if (fs->blksz != 1024) 156 count = 0; 157 else 158 count = 1; 159 160 while (*ptr == 255) { 161 ptr++; 162 count += 8; 163 if (count == (fs->blksz * 8)) 164 return -1; 165 } 166 167 for (j = 0; j < fs->blksz; j++) { 168 input = *ptr; 169 int i = 0; 170 while (i <= 7) { 171 operand = 1 << i; 172 status = input & operand; 173 if (status) { 174 i++; 175 count++; 176 } else { 177 *ptr |= operand; 178 return count; 179 } 180 } 181 ptr = ptr + 1; 182 } 183 184 return -1; 185 } 186 187 int ext4fs_set_block_bmap(long int blockno, unsigned char *buffer, int index) 188 { 189 int i, remainder, status; 190 unsigned char *ptr = buffer; 191 unsigned char operand; 192 i = blockno / 8; 193 remainder = blockno % 8; 194 int blocksize = EXT2_BLOCK_SIZE(ext4fs_root); 195 196 i = i - (index * blocksize); 197 if (blocksize != 1024) { 198 ptr = ptr + i; 199 operand = 1 << remainder; 200 status = *ptr & operand; 201 if (status) 202 return -1; 203 204 *ptr = *ptr | operand; 205 return 0; 206 } else { 207 if (remainder == 0) { 208 ptr = ptr + i - 1; 209 operand = (1 << 7); 210 } else { 211 ptr = ptr + i; 212 operand = (1 << (remainder - 1)); 213 } 214 status = *ptr & operand; 215 if (status) 216 return -1; 217 218 *ptr = *ptr | operand; 219 return 0; 220 } 221 } 222 223 void ext4fs_reset_block_bmap(long int blockno, unsigned char *buffer, int index) 224 { 225 int i, remainder, status; 226 unsigned char *ptr = buffer; 227 unsigned char operand; 228 i = blockno / 8; 229 remainder = blockno % 8; 230 int blocksize = EXT2_BLOCK_SIZE(ext4fs_root); 231 232 i = i - (index * blocksize); 233 if (blocksize != 1024) { 234 ptr = ptr + i; 235 operand = (1 << remainder); 236 status = *ptr & operand; 237 if (status) 238 *ptr = *ptr & ~(operand); 239 } else { 240 if (remainder == 0) { 241 ptr = ptr + i - 1; 242 operand = (1 << 7); 243 } else { 244 ptr = ptr + i; 245 operand = (1 << (remainder - 1)); 246 } 247 status = *ptr & operand; 248 if (status) 249 *ptr = *ptr & ~(operand); 250 } 251 } 252 253 int ext4fs_set_inode_bmap(int inode_no, unsigned char *buffer, int index) 254 { 255 int i, remainder, status; 256 unsigned char *ptr = buffer; 257 unsigned char operand; 258 259 inode_no -= (index * ext4fs_root->sblock.inodes_per_group); 260 i = inode_no / 8; 261 remainder = inode_no % 8; 262 if (remainder == 0) { 263 ptr = ptr + i - 1; 264 operand = (1 << 7); 265 } else { 266 ptr = ptr + i; 267 operand = (1 << (remainder - 1)); 268 } 269 status = *ptr & operand; 270 if (status) 271 return -1; 272 273 *ptr = *ptr | operand; 274 275 return 0; 276 } 277 278 void ext4fs_reset_inode_bmap(int inode_no, unsigned char *buffer, int index) 279 { 280 int i, remainder, status; 281 unsigned char *ptr = buffer; 282 unsigned char operand; 283 284 inode_no -= (index * ext4fs_root->sblock.inodes_per_group); 285 i = inode_no / 8; 286 remainder = inode_no % 8; 287 if (remainder == 0) { 288 ptr = ptr + i - 1; 289 operand = (1 << 7); 290 } else { 291 ptr = ptr + i; 292 operand = (1 << (remainder - 1)); 293 } 294 status = *ptr & operand; 295 if (status) 296 *ptr = *ptr & ~(operand); 297 } 298 299 int ext4fs_checksum_update(unsigned int i) 300 { 301 struct ext2_block_group *desc; 302 struct ext_filesystem *fs = get_fs(); 303 __u16 crc = 0; 304 305 desc = (struct ext2_block_group *)&fs->bgd[i]; 306 if (fs->sb->feature_ro_compat & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) { 307 int offset = offsetof(struct ext2_block_group, bg_checksum); 308 309 crc = ext2fs_crc16(~0, fs->sb->unique_id, 310 sizeof(fs->sb->unique_id)); 311 crc = ext2fs_crc16(crc, &i, sizeof(i)); 312 crc = ext2fs_crc16(crc, desc, offset); 313 offset += sizeof(desc->bg_checksum); /* skip checksum */ 314 assert(offset == sizeof(*desc)); 315 } 316 317 return crc; 318 } 319 320 static int check_void_in_dentry(struct ext2_dirent *dir, char *filename) 321 { 322 int dentry_length; 323 int sizeof_void_space; 324 int new_entry_byte_reqd; 325 short padding_factor = 0; 326 327 if (dir->namelen % 4 != 0) 328 padding_factor = 4 - (dir->namelen % 4); 329 330 dentry_length = sizeof(struct ext2_dirent) + 331 dir->namelen + padding_factor; 332 sizeof_void_space = dir->direntlen - dentry_length; 333 if (sizeof_void_space == 0) 334 return 0; 335 336 padding_factor = 0; 337 if (strlen(filename) % 4 != 0) 338 padding_factor = 4 - (strlen(filename) % 4); 339 340 new_entry_byte_reqd = strlen(filename) + 341 sizeof(struct ext2_dirent) + padding_factor; 342 if (sizeof_void_space >= new_entry_byte_reqd) { 343 dir->direntlen = dentry_length; 344 return sizeof_void_space; 345 } 346 347 return 0; 348 } 349 350 void ext4fs_update_parent_dentry(char *filename, int *p_ino, int file_type) 351 { 352 unsigned int *zero_buffer = NULL; 353 char *root_first_block_buffer = NULL; 354 int direct_blk_idx; 355 long int root_blknr; 356 long int first_block_no_of_root = 0; 357 long int previous_blknr = -1; 358 int totalbytes = 0; 359 short int padding_factor = 0; 360 unsigned int new_entry_byte_reqd; 361 unsigned int last_entry_dirlen; 362 int sizeof_void_space = 0; 363 int templength = 0; 364 int inodeno; 365 int status; 366 struct ext_filesystem *fs = get_fs(); 367 /* directory entry */ 368 struct ext2_dirent *dir; 369 char *temp_dir = NULL; 370 371 zero_buffer = zalloc(fs->blksz); 372 if (!zero_buffer) { 373 printf("No Memory\n"); 374 return; 375 } 376 root_first_block_buffer = zalloc(fs->blksz); 377 if (!root_first_block_buffer) { 378 free(zero_buffer); 379 printf("No Memory\n"); 380 return; 381 } 382 restart: 383 384 /* read the block no allocated to a file */ 385 for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS; 386 direct_blk_idx++) { 387 root_blknr = read_allocated_block(g_parent_inode, 388 direct_blk_idx); 389 if (root_blknr == 0) { 390 first_block_no_of_root = previous_blknr; 391 break; 392 } 393 previous_blknr = root_blknr; 394 } 395 396 status = ext4fs_devread((lbaint_t)first_block_no_of_root 397 * fs->sect_perblk, 398 0, fs->blksz, root_first_block_buffer); 399 if (status == 0) 400 goto fail; 401 402 if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root)) 403 goto fail; 404 dir = (struct ext2_dirent *)root_first_block_buffer; 405 totalbytes = 0; 406 while (dir->direntlen > 0) { 407 /* 408 * blocksize-totalbytes because last directory length 409 * i.e. dir->direntlen is free availble space in the 410 * block that means it is a last entry of directory 411 * entry 412 */ 413 414 /* traversing the each directory entry */ 415 if (fs->blksz - totalbytes == dir->direntlen) { 416 if (strlen(filename) % 4 != 0) 417 padding_factor = 4 - (strlen(filename) % 4); 418 419 new_entry_byte_reqd = strlen(filename) + 420 sizeof(struct ext2_dirent) + padding_factor; 421 padding_factor = 0; 422 /* 423 * update last directory entry length to its 424 * length because we are creating new directory 425 * entry 426 */ 427 if (dir->namelen % 4 != 0) 428 padding_factor = 4 - (dir->namelen % 4); 429 430 last_entry_dirlen = dir->namelen + 431 sizeof(struct ext2_dirent) + padding_factor; 432 if ((fs->blksz - totalbytes - last_entry_dirlen) < 433 new_entry_byte_reqd) { 434 printf("1st Block Full:Allocate new block\n"); 435 436 if (direct_blk_idx == INDIRECT_BLOCKS - 1) { 437 printf("Directory exceeds limit\n"); 438 goto fail; 439 } 440 g_parent_inode->b.blocks.dir_blocks 441 [direct_blk_idx] = ext4fs_get_new_blk_no(); 442 if (g_parent_inode->b.blocks.dir_blocks 443 [direct_blk_idx] == -1) { 444 printf("no block left to assign\n"); 445 goto fail; 446 } 447 put_ext4(((uint64_t) 448 ((uint64_t)g_parent_inode->b. 449 blocks.dir_blocks[direct_blk_idx] * 450 (uint64_t)fs->blksz)), zero_buffer, fs->blksz); 451 g_parent_inode->size = 452 g_parent_inode->size + fs->blksz; 453 g_parent_inode->blockcnt = 454 g_parent_inode->blockcnt + fs->sect_perblk; 455 if (ext4fs_put_metadata 456 (root_first_block_buffer, 457 first_block_no_of_root)) 458 goto fail; 459 goto restart; 460 } 461 dir->direntlen = last_entry_dirlen; 462 break; 463 } 464 465 templength = dir->direntlen; 466 totalbytes = totalbytes + templength; 467 sizeof_void_space = check_void_in_dentry(dir, filename); 468 if (sizeof_void_space) 469 break; 470 471 dir = (struct ext2_dirent *)((char *)dir + templength); 472 } 473 474 /* make a pointer ready for creating next directory entry */ 475 templength = dir->direntlen; 476 totalbytes = totalbytes + templength; 477 dir = (struct ext2_dirent *)((char *)dir + templength); 478 479 /* get the next available inode number */ 480 inodeno = ext4fs_get_new_inode_no(); 481 if (inodeno == -1) { 482 printf("no inode left to assign\n"); 483 goto fail; 484 } 485 dir->inode = inodeno; 486 if (sizeof_void_space) 487 dir->direntlen = sizeof_void_space; 488 else 489 dir->direntlen = fs->blksz - totalbytes; 490 491 dir->namelen = strlen(filename); 492 dir->filetype = FILETYPE_REG; /* regular file */ 493 temp_dir = (char *)dir; 494 temp_dir = temp_dir + sizeof(struct ext2_dirent); 495 memcpy(temp_dir, filename, strlen(filename)); 496 497 *p_ino = inodeno; 498 499 /* update or write the 1st block of root inode */ 500 if (ext4fs_put_metadata(root_first_block_buffer, 501 first_block_no_of_root)) 502 goto fail; 503 504 fail: 505 free(zero_buffer); 506 free(root_first_block_buffer); 507 } 508 509 static int search_dir(struct ext2_inode *parent_inode, char *dirname) 510 { 511 int status; 512 int inodeno; 513 int totalbytes; 514 int templength; 515 int direct_blk_idx; 516 long int blknr; 517 int found = 0; 518 char *ptr = NULL; 519 unsigned char *block_buffer = NULL; 520 struct ext2_dirent *dir = NULL; 521 struct ext2_dirent *previous_dir = NULL; 522 struct ext_filesystem *fs = get_fs(); 523 524 /* read the block no allocated to a file */ 525 for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS; 526 direct_blk_idx++) { 527 blknr = read_allocated_block(parent_inode, direct_blk_idx); 528 if (blknr == 0) 529 goto fail; 530 531 /* read the blocks of parenet inode */ 532 block_buffer = zalloc(fs->blksz); 533 if (!block_buffer) 534 goto fail; 535 536 status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk, 537 0, fs->blksz, (char *)block_buffer); 538 if (status == 0) 539 goto fail; 540 541 dir = (struct ext2_dirent *)block_buffer; 542 ptr = (char *)dir; 543 totalbytes = 0; 544 while (dir->direntlen >= 0) { 545 /* 546 * blocksize-totalbytes because last directory 547 * length i.e.,*dir->direntlen is free availble 548 * space in the block that means 549 * it is a last entry of directory entry 550 */ 551 if (strlen(dirname) == dir->namelen) { 552 if (strncmp(dirname, ptr + 553 sizeof(struct ext2_dirent), 554 dir->namelen) == 0) { 555 previous_dir->direntlen += 556 dir->direntlen; 557 inodeno = dir->inode; 558 dir->inode = 0; 559 found = 1; 560 break; 561 } 562 } 563 564 if (fs->blksz - totalbytes == dir->direntlen) 565 break; 566 567 /* traversing the each directory entry */ 568 templength = dir->direntlen; 569 totalbytes = totalbytes + templength; 570 previous_dir = dir; 571 dir = (struct ext2_dirent *)((char *)dir + templength); 572 ptr = (char *)dir; 573 } 574 575 if (found == 1) { 576 free(block_buffer); 577 block_buffer = NULL; 578 return inodeno; 579 } 580 581 free(block_buffer); 582 block_buffer = NULL; 583 } 584 585 fail: 586 free(block_buffer); 587 588 return -1; 589 } 590 591 static int find_dir_depth(char *dirname) 592 { 593 char *token = strtok(dirname, "/"); 594 int count = 0; 595 while (token != NULL) { 596 token = strtok(NULL, "/"); 597 count++; 598 } 599 return count + 1 + 1; 600 /* 601 * for example for string /home/temp 602 * depth=home(1)+temp(1)+1 extra for NULL; 603 * so count is 4; 604 */ 605 } 606 607 static int parse_path(char **arr, char *dirname) 608 { 609 char *token = strtok(dirname, "/"); 610 int i = 0; 611 612 /* add root */ 613 arr[i] = zalloc(strlen("/") + 1); 614 if (!arr[i]) 615 return -ENOMEM; 616 617 arr[i++] = "/"; 618 619 /* add each path entry after root */ 620 while (token != NULL) { 621 arr[i] = zalloc(strlen(token) + 1); 622 if (!arr[i]) 623 return -ENOMEM; 624 memcpy(arr[i++], token, strlen(token)); 625 token = strtok(NULL, "/"); 626 } 627 arr[i] = NULL; 628 629 return 0; 630 } 631 632 int ext4fs_iget(int inode_no, struct ext2_inode *inode) 633 { 634 if (ext4fs_read_inode(ext4fs_root, inode_no, inode) == 0) 635 return -1; 636 637 return 0; 638 } 639 640 /* 641 * Function: ext4fs_get_parent_inode_num 642 * Return Value: inode Number of the parent directory of file/Directory to be 643 * created 644 * dirname : Input parmater, input path name of the file/directory to be created 645 * dname : Output parameter, to be filled with the name of the directory 646 * extracted from dirname 647 */ 648 int ext4fs_get_parent_inode_num(const char *dirname, char *dname, int flags) 649 { 650 int i; 651 int depth = 0; 652 int matched_inode_no; 653 int result_inode_no = -1; 654 char **ptr = NULL; 655 char *depth_dirname = NULL; 656 char *parse_dirname = NULL; 657 struct ext2_inode *parent_inode = NULL; 658 struct ext2_inode *first_inode = NULL; 659 struct ext2_inode temp_inode; 660 661 if (*dirname != '/') { 662 printf("Please supply Absolute path\n"); 663 return -1; 664 } 665 666 /* TODO: input validation make equivalent to linux */ 667 depth_dirname = zalloc(strlen(dirname) + 1); 668 if (!depth_dirname) 669 return -ENOMEM; 670 671 memcpy(depth_dirname, dirname, strlen(dirname)); 672 depth = find_dir_depth(depth_dirname); 673 parse_dirname = zalloc(strlen(dirname) + 1); 674 if (!parse_dirname) 675 goto fail; 676 memcpy(parse_dirname, dirname, strlen(dirname)); 677 678 /* allocate memory for each directory level */ 679 ptr = zalloc((depth) * sizeof(char *)); 680 if (!ptr) 681 goto fail; 682 if (parse_path(ptr, parse_dirname)) 683 goto fail; 684 parent_inode = zalloc(sizeof(struct ext2_inode)); 685 if (!parent_inode) 686 goto fail; 687 first_inode = zalloc(sizeof(struct ext2_inode)); 688 if (!first_inode) 689 goto fail; 690 memcpy(parent_inode, ext4fs_root->inode, sizeof(struct ext2_inode)); 691 memcpy(first_inode, parent_inode, sizeof(struct ext2_inode)); 692 if (flags & F_FILE) 693 result_inode_no = EXT2_ROOT_INO; 694 for (i = 1; i < depth; i++) { 695 matched_inode_no = search_dir(parent_inode, ptr[i]); 696 if (matched_inode_no == -1) { 697 if (ptr[i + 1] == NULL && i == 1) { 698 result_inode_no = EXT2_ROOT_INO; 699 goto end; 700 } else { 701 if (ptr[i + 1] == NULL) 702 break; 703 printf("Invalid path\n"); 704 result_inode_no = -1; 705 goto fail; 706 } 707 } else { 708 if (ptr[i + 1] != NULL) { 709 memset(parent_inode, '\0', 710 sizeof(struct ext2_inode)); 711 if (ext4fs_iget(matched_inode_no, 712 parent_inode)) { 713 result_inode_no = -1; 714 goto fail; 715 } 716 result_inode_no = matched_inode_no; 717 } else { 718 break; 719 } 720 } 721 } 722 723 end: 724 if (i == 1) 725 matched_inode_no = search_dir(first_inode, ptr[i]); 726 else 727 matched_inode_no = search_dir(parent_inode, ptr[i]); 728 729 if (matched_inode_no != -1) { 730 ext4fs_iget(matched_inode_no, &temp_inode); 731 if (temp_inode.mode & S_IFDIR) { 732 printf("It is a Directory\n"); 733 result_inode_no = -1; 734 goto fail; 735 } 736 } 737 738 if (strlen(ptr[i]) > 256) { 739 result_inode_no = -1; 740 goto fail; 741 } 742 memcpy(dname, ptr[i], strlen(ptr[i])); 743 744 fail: 745 free(depth_dirname); 746 free(parse_dirname); 747 free(ptr); 748 free(parent_inode); 749 free(first_inode); 750 751 return result_inode_no; 752 } 753 754 static int check_filename(char *filename, unsigned int blknr) 755 { 756 unsigned int first_block_no_of_root; 757 int totalbytes = 0; 758 int templength = 0; 759 int status, inodeno; 760 int found = 0; 761 char *root_first_block_buffer = NULL; 762 char *root_first_block_addr = NULL; 763 struct ext2_dirent *dir = NULL; 764 struct ext2_dirent *previous_dir = NULL; 765 char *ptr = NULL; 766 struct ext_filesystem *fs = get_fs(); 767 768 /* get the first block of root */ 769 first_block_no_of_root = blknr; 770 root_first_block_buffer = zalloc(fs->blksz); 771 if (!root_first_block_buffer) 772 return -ENOMEM; 773 root_first_block_addr = root_first_block_buffer; 774 status = ext4fs_devread((lbaint_t)first_block_no_of_root * 775 fs->sect_perblk, 0, 776 fs->blksz, root_first_block_buffer); 777 if (status == 0) 778 goto fail; 779 780 if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root)) 781 goto fail; 782 dir = (struct ext2_dirent *)root_first_block_buffer; 783 ptr = (char *)dir; 784 totalbytes = 0; 785 while (dir->direntlen >= 0) { 786 /* 787 * blocksize-totalbytes because last 788 * directory length i.e., *dir->direntlen 789 * is free availble space in the block that 790 * means it is a last entry of directory entry 791 */ 792 if (strlen(filename) == dir->namelen) { 793 if (strncmp(filename, ptr + sizeof(struct ext2_dirent), 794 dir->namelen) == 0) { 795 printf("file found deleting\n"); 796 previous_dir->direntlen += dir->direntlen; 797 inodeno = dir->inode; 798 dir->inode = 0; 799 found = 1; 800 break; 801 } 802 } 803 804 if (fs->blksz - totalbytes == dir->direntlen) 805 break; 806 807 /* traversing the each directory entry */ 808 templength = dir->direntlen; 809 totalbytes = totalbytes + templength; 810 previous_dir = dir; 811 dir = (struct ext2_dirent *)((char *)dir + templength); 812 ptr = (char *)dir; 813 } 814 815 816 if (found == 1) { 817 if (ext4fs_put_metadata(root_first_block_addr, 818 first_block_no_of_root)) 819 goto fail; 820 return inodeno; 821 } 822 fail: 823 free(root_first_block_buffer); 824 825 return -1; 826 } 827 828 int ext4fs_filename_check(char *filename) 829 { 830 short direct_blk_idx = 0; 831 long int blknr = -1; 832 int inodeno = -1; 833 834 /* read the block no allocated to a file */ 835 for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS; 836 direct_blk_idx++) { 837 blknr = read_allocated_block(g_parent_inode, direct_blk_idx); 838 if (blknr == 0) 839 break; 840 inodeno = check_filename(filename, blknr); 841 if (inodeno != -1) 842 return inodeno; 843 } 844 845 return -1; 846 } 847 848 long int ext4fs_get_new_blk_no(void) 849 { 850 short i; 851 short status; 852 int remainder; 853 unsigned int bg_idx; 854 static int prev_bg_bitmap_index = -1; 855 unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group; 856 struct ext_filesystem *fs = get_fs(); 857 char *journal_buffer = zalloc(fs->blksz); 858 char *zero_buffer = zalloc(fs->blksz); 859 if (!journal_buffer || !zero_buffer) 860 goto fail; 861 struct ext2_block_group *bgd = (struct ext2_block_group *)fs->gdtable; 862 863 if (fs->first_pass_bbmap == 0) { 864 for (i = 0; i < fs->no_blkgrp; i++) { 865 if (bgd[i].free_blocks) { 866 if (bgd[i].bg_flags & EXT4_BG_BLOCK_UNINIT) { 867 put_ext4(((uint64_t) ((uint64_t)bgd[i].block_id * 868 (uint64_t)fs->blksz)), 869 zero_buffer, fs->blksz); 870 bgd[i].bg_flags = 871 bgd[i]. 872 bg_flags & ~EXT4_BG_BLOCK_UNINIT; 873 memcpy(fs->blk_bmaps[i], zero_buffer, 874 fs->blksz); 875 } 876 fs->curr_blkno = 877 _get_new_blk_no(fs->blk_bmaps[i]); 878 if (fs->curr_blkno == -1) 879 /* if block bitmap is completely fill */ 880 continue; 881 fs->curr_blkno = fs->curr_blkno + 882 (i * fs->blksz * 8); 883 fs->first_pass_bbmap++; 884 bgd[i].free_blocks--; 885 fs->sb->free_blocks--; 886 status = ext4fs_devread((lbaint_t) 887 bgd[i].block_id * 888 fs->sect_perblk, 0, 889 fs->blksz, 890 journal_buffer); 891 if (status == 0) 892 goto fail; 893 if (ext4fs_log_journal(journal_buffer, 894 bgd[i].block_id)) 895 goto fail; 896 goto success; 897 } else { 898 debug("no space left on block group %d\n", i); 899 } 900 } 901 902 goto fail; 903 } else { 904 restart: 905 fs->curr_blkno++; 906 /* get the blockbitmap index respective to blockno */ 907 bg_idx = fs->curr_blkno / blk_per_grp; 908 if (fs->blksz == 1024) { 909 remainder = fs->curr_blkno % blk_per_grp; 910 if (!remainder) 911 bg_idx--; 912 } 913 914 /* 915 * To skip completely filled block group bitmaps 916 * Optimize the block allocation 917 */ 918 if (bg_idx >= fs->no_blkgrp) 919 goto fail; 920 921 if (bgd[bg_idx].free_blocks == 0) { 922 debug("block group %u is full. Skipping\n", bg_idx); 923 fs->curr_blkno = fs->curr_blkno + blk_per_grp; 924 fs->curr_blkno--; 925 goto restart; 926 } 927 928 if (bgd[bg_idx].bg_flags & EXT4_BG_BLOCK_UNINIT) { 929 memset(zero_buffer, '\0', fs->blksz); 930 put_ext4(((uint64_t) ((uint64_t)bgd[bg_idx].block_id * 931 (uint64_t)fs->blksz)), zero_buffer, fs->blksz); 932 memcpy(fs->blk_bmaps[bg_idx], zero_buffer, fs->blksz); 933 bgd[bg_idx].bg_flags = bgd[bg_idx].bg_flags & 934 ~EXT4_BG_BLOCK_UNINIT; 935 } 936 937 if (ext4fs_set_block_bmap(fs->curr_blkno, fs->blk_bmaps[bg_idx], 938 bg_idx) != 0) { 939 debug("going for restart for the block no %ld %u\n", 940 fs->curr_blkno, bg_idx); 941 goto restart; 942 } 943 944 /* journal backup */ 945 if (prev_bg_bitmap_index != bg_idx) { 946 memset(journal_buffer, '\0', fs->blksz); 947 status = ext4fs_devread((lbaint_t)bgd[bg_idx].block_id 948 * fs->sect_perblk, 949 0, fs->blksz, journal_buffer); 950 if (status == 0) 951 goto fail; 952 if (ext4fs_log_journal(journal_buffer, 953 bgd[bg_idx].block_id)) 954 goto fail; 955 956 prev_bg_bitmap_index = bg_idx; 957 } 958 bgd[bg_idx].free_blocks--; 959 fs->sb->free_blocks--; 960 goto success; 961 } 962 success: 963 free(journal_buffer); 964 free(zero_buffer); 965 966 return fs->curr_blkno; 967 fail: 968 free(journal_buffer); 969 free(zero_buffer); 970 971 return -1; 972 } 973 974 int ext4fs_get_new_inode_no(void) 975 { 976 short i; 977 short status; 978 unsigned int ibmap_idx; 979 static int prev_inode_bitmap_index = -1; 980 unsigned int inodes_per_grp = ext4fs_root->sblock.inodes_per_group; 981 struct ext_filesystem *fs = get_fs(); 982 char *journal_buffer = zalloc(fs->blksz); 983 char *zero_buffer = zalloc(fs->blksz); 984 if (!journal_buffer || !zero_buffer) 985 goto fail; 986 struct ext2_block_group *bgd = (struct ext2_block_group *)fs->gdtable; 987 988 if (fs->first_pass_ibmap == 0) { 989 for (i = 0; i < fs->no_blkgrp; i++) { 990 if (bgd[i].free_inodes) { 991 if (bgd[i].bg_itable_unused != 992 bgd[i].free_inodes) 993 bgd[i].bg_itable_unused = 994 bgd[i].free_inodes; 995 if (bgd[i].bg_flags & EXT4_BG_INODE_UNINIT) { 996 put_ext4(((uint64_t) 997 ((uint64_t)bgd[i].inode_id * 998 (uint64_t)fs->blksz)), 999 zero_buffer, fs->blksz); 1000 bgd[i].bg_flags = bgd[i].bg_flags & 1001 ~EXT4_BG_INODE_UNINIT; 1002 memcpy(fs->inode_bmaps[i], 1003 zero_buffer, fs->blksz); 1004 } 1005 fs->curr_inode_no = 1006 _get_new_inode_no(fs->inode_bmaps[i]); 1007 if (fs->curr_inode_no == -1) 1008 /* if block bitmap is completely fill */ 1009 continue; 1010 fs->curr_inode_no = fs->curr_inode_no + 1011 (i * inodes_per_grp); 1012 fs->first_pass_ibmap++; 1013 bgd[i].free_inodes--; 1014 bgd[i].bg_itable_unused--; 1015 fs->sb->free_inodes--; 1016 status = ext4fs_devread((lbaint_t) 1017 bgd[i].inode_id * 1018 fs->sect_perblk, 0, 1019 fs->blksz, 1020 journal_buffer); 1021 if (status == 0) 1022 goto fail; 1023 if (ext4fs_log_journal(journal_buffer, 1024 bgd[i].inode_id)) 1025 goto fail; 1026 goto success; 1027 } else 1028 debug("no inode left on block group %d\n", i); 1029 } 1030 goto fail; 1031 } else { 1032 restart: 1033 fs->curr_inode_no++; 1034 /* get the blockbitmap index respective to blockno */ 1035 ibmap_idx = fs->curr_inode_no / inodes_per_grp; 1036 if (bgd[ibmap_idx].bg_flags & EXT4_BG_INODE_UNINIT) { 1037 memset(zero_buffer, '\0', fs->blksz); 1038 put_ext4(((uint64_t) ((uint64_t)bgd[ibmap_idx].inode_id * 1039 (uint64_t)fs->blksz)), zero_buffer, 1040 fs->blksz); 1041 bgd[ibmap_idx].bg_flags = 1042 bgd[ibmap_idx].bg_flags & ~EXT4_BG_INODE_UNINIT; 1043 memcpy(fs->inode_bmaps[ibmap_idx], zero_buffer, 1044 fs->blksz); 1045 } 1046 1047 if (ext4fs_set_inode_bmap(fs->curr_inode_no, 1048 fs->inode_bmaps[ibmap_idx], 1049 ibmap_idx) != 0) { 1050 debug("going for restart for the block no %d %u\n", 1051 fs->curr_inode_no, ibmap_idx); 1052 goto restart; 1053 } 1054 1055 /* journal backup */ 1056 if (prev_inode_bitmap_index != ibmap_idx) { 1057 memset(journal_buffer, '\0', fs->blksz); 1058 status = ext4fs_devread((lbaint_t) 1059 bgd[ibmap_idx].inode_id 1060 * fs->sect_perblk, 1061 0, fs->blksz, journal_buffer); 1062 if (status == 0) 1063 goto fail; 1064 if (ext4fs_log_journal(journal_buffer, 1065 bgd[ibmap_idx].inode_id)) 1066 goto fail; 1067 prev_inode_bitmap_index = ibmap_idx; 1068 } 1069 if (bgd[ibmap_idx].bg_itable_unused != 1070 bgd[ibmap_idx].free_inodes) 1071 bgd[ibmap_idx].bg_itable_unused = 1072 bgd[ibmap_idx].free_inodes; 1073 bgd[ibmap_idx].free_inodes--; 1074 bgd[ibmap_idx].bg_itable_unused--; 1075 fs->sb->free_inodes--; 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 unsigned int *si_buffer = NULL; 1103 unsigned int *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 = 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 = 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 unsigned int *di_parent_buffer = NULL; 1164 unsigned int *di_child_buff = NULL; 1165 unsigned int *di_block_start_addr = NULL; 1166 unsigned int *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 = 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 = 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 = 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 unsigned int *ti_gp_buff = NULL; 1272 unsigned int *ti_parent_buff = NULL; 1273 unsigned int *ti_child_buff = NULL; 1274 unsigned int *ti_gp_buff_start_addr = NULL; 1275 unsigned int *ti_pbuff_start_addr = NULL; 1276 unsigned int *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 goto fail; 1284 } 1285 ti_gp_buff = zalloc(fs->blksz); 1286 if (!ti_gp_buff) 1287 goto fail; 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 = 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 fail; 1318 } 1319 ti_child_buff = zalloc(fs->blksz); 1320 if (!ti_child_buff) 1321 goto fail; 1322 1323 ti_cbuff_start_addr = ti_child_buff; 1324 *ti_parent_buff = 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 goto fail; 1338 } 1339 *ti_child_buff = actual_block_no; 1340 debug("TIAB %ld: %u\n", actual_block_no, 1341 *total_remaining_blocks); 1342 1343 ti_child_buff++; 1344 (*total_remaining_blocks)--; 1345 if (*total_remaining_blocks == 0) 1346 break; 1347 } 1348 /* write the child block */ 1349 put_ext4(((uint64_t) ((uint64_t)ti_child_blockno * 1350 (uint64_t)fs->blksz)), 1351 ti_cbuff_start_addr, fs->blksz); 1352 free(ti_cbuff_start_addr); 1353 1354 if (*total_remaining_blocks == 0) 1355 break; 1356 } 1357 /* write the parent block */ 1358 put_ext4(((uint64_t) ((uint64_t)ti_parent_blockno * (uint64_t)fs->blksz)), 1359 ti_pbuff_start_addr, fs->blksz); 1360 free(ti_pbuff_start_addr); 1361 1362 if (*total_remaining_blocks == 0) 1363 break; 1364 } 1365 /* write the grand parent block */ 1366 put_ext4(((uint64_t) ((uint64_t)ti_gp_blockno * (uint64_t)fs->blksz)), 1367 ti_gp_buff_start_addr, fs->blksz); 1368 file_inode->b.blocks.triple_indir_block = ti_gp_blockno; 1369 } 1370 fail: 1371 free(ti_gp_buff_start_addr); 1372 } 1373 1374 void ext4fs_allocate_blocks(struct ext2_inode *file_inode, 1375 unsigned int total_remaining_blocks, 1376 unsigned int *total_no_of_block) 1377 { 1378 short i; 1379 long int direct_blockno; 1380 unsigned int no_blks_reqd = 0; 1381 1382 /* allocation of direct blocks */ 1383 for (i = 0; i < INDIRECT_BLOCKS; i++) { 1384 direct_blockno = ext4fs_get_new_blk_no(); 1385 if (direct_blockno == -1) { 1386 printf("no block left to assign\n"); 1387 return; 1388 } 1389 file_inode->b.blocks.dir_blocks[i] = direct_blockno; 1390 debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks); 1391 1392 total_remaining_blocks--; 1393 if (total_remaining_blocks == 0) 1394 break; 1395 } 1396 1397 alloc_single_indirect_block(file_inode, &total_remaining_blocks, 1398 &no_blks_reqd); 1399 alloc_double_indirect_block(file_inode, &total_remaining_blocks, 1400 &no_blks_reqd); 1401 alloc_triple_indirect_block(file_inode, &total_remaining_blocks, 1402 &no_blks_reqd); 1403 *total_no_of_block += no_blks_reqd; 1404 } 1405 1406 #endif 1407 1408 static struct ext4_extent_header *ext4fs_get_extent_block 1409 (struct ext2_data *data, char *buf, 1410 struct ext4_extent_header *ext_block, 1411 uint32_t fileblock, int log2_blksz) 1412 { 1413 struct ext4_extent_idx *index; 1414 unsigned long long block; 1415 int blksz = EXT2_BLOCK_SIZE(data); 1416 int i; 1417 1418 while (1) { 1419 index = (struct ext4_extent_idx *)(ext_block + 1); 1420 1421 if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC) 1422 return 0; 1423 1424 if (ext_block->eh_depth == 0) 1425 return ext_block; 1426 i = -1; 1427 do { 1428 i++; 1429 if (i >= le16_to_cpu(ext_block->eh_entries)) 1430 break; 1431 } while (fileblock >= le32_to_cpu(index[i].ei_block)); 1432 1433 if (--i < 0) 1434 return 0; 1435 1436 block = le16_to_cpu(index[i].ei_leaf_hi); 1437 block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo); 1438 1439 if (ext4fs_devread((lbaint_t)block << log2_blksz, 0, blksz, 1440 buf)) 1441 ext_block = (struct ext4_extent_header *)buf; 1442 else 1443 return 0; 1444 } 1445 } 1446 1447 static int ext4fs_blockgroup 1448 (struct ext2_data *data, int group, struct ext2_block_group *blkgrp) 1449 { 1450 long int blkno; 1451 unsigned int blkoff, desc_per_blk; 1452 int log2blksz = get_fs()->dev_desc->log2blksz; 1453 1454 desc_per_blk = EXT2_BLOCK_SIZE(data) / sizeof(struct ext2_block_group); 1455 1456 blkno = __le32_to_cpu(data->sblock.first_data_block) + 1 + 1457 group / desc_per_blk; 1458 blkoff = (group % desc_per_blk) * sizeof(struct ext2_block_group); 1459 1460 debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n", 1461 group, blkno, blkoff); 1462 1463 return ext4fs_devread((lbaint_t)blkno << 1464 (LOG2_BLOCK_SIZE(data) - log2blksz), 1465 blkoff, sizeof(struct ext2_block_group), 1466 (char *)blkgrp); 1467 } 1468 1469 int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode) 1470 { 1471 struct ext2_block_group blkgrp; 1472 struct ext2_sblock *sblock = &data->sblock; 1473 struct ext_filesystem *fs = get_fs(); 1474 int log2blksz = get_fs()->dev_desc->log2blksz; 1475 int inodes_per_block, status; 1476 long int blkno; 1477 unsigned int blkoff; 1478 1479 /* It is easier to calculate if the first inode is 0. */ 1480 ino--; 1481 status = ext4fs_blockgroup(data, ino / __le32_to_cpu 1482 (sblock->inodes_per_group), &blkgrp); 1483 if (status == 0) 1484 return 0; 1485 1486 inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz; 1487 blkno = __le32_to_cpu(blkgrp.inode_table_id) + 1488 (ino % __le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block; 1489 blkoff = (ino % inodes_per_block) * fs->inodesz; 1490 /* Read the inode. */ 1491 status = ext4fs_devread((lbaint_t)blkno << (LOG2_BLOCK_SIZE(data) - 1492 log2blksz), blkoff, 1493 sizeof(struct ext2_inode), (char *)inode); 1494 if (status == 0) 1495 return 0; 1496 1497 return 1; 1498 } 1499 1500 long int read_allocated_block(struct ext2_inode *inode, int fileblock) 1501 { 1502 long int blknr; 1503 int blksz; 1504 int log2_blksz; 1505 int status; 1506 long int rblock; 1507 long int perblock_parent; 1508 long int perblock_child; 1509 unsigned long long start; 1510 /* get the blocksize of the filesystem */ 1511 blksz = EXT2_BLOCK_SIZE(ext4fs_root); 1512 log2_blksz = LOG2_BLOCK_SIZE(ext4fs_root) 1513 - get_fs()->dev_desc->log2blksz; 1514 1515 if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) { 1516 char *buf = zalloc(blksz); 1517 if (!buf) 1518 return -ENOMEM; 1519 struct ext4_extent_header *ext_block; 1520 struct ext4_extent *extent; 1521 int i = -1; 1522 ext_block = 1523 ext4fs_get_extent_block(ext4fs_root, buf, 1524 (struct ext4_extent_header *) 1525 inode->b.blocks.dir_blocks, 1526 fileblock, log2_blksz); 1527 if (!ext_block) { 1528 printf("invalid extent block\n"); 1529 free(buf); 1530 return -EINVAL; 1531 } 1532 1533 extent = (struct ext4_extent *)(ext_block + 1); 1534 1535 do { 1536 i++; 1537 if (i >= le16_to_cpu(ext_block->eh_entries)) 1538 break; 1539 } while (fileblock >= le32_to_cpu(extent[i].ee_block)); 1540 if (--i >= 0) { 1541 fileblock -= le32_to_cpu(extent[i].ee_block); 1542 if (fileblock >= le16_to_cpu(extent[i].ee_len)) { 1543 free(buf); 1544 return 0; 1545 } 1546 1547 start = le16_to_cpu(extent[i].ee_start_hi); 1548 start = (start << 32) + 1549 le32_to_cpu(extent[i].ee_start_lo); 1550 free(buf); 1551 return fileblock + start; 1552 } 1553 1554 printf("Extent Error\n"); 1555 free(buf); 1556 return -1; 1557 } 1558 1559 /* Direct blocks. */ 1560 if (fileblock < INDIRECT_BLOCKS) 1561 blknr = __le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]); 1562 1563 /* Indirect. */ 1564 else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) { 1565 if (ext4fs_indir1_block == NULL) { 1566 ext4fs_indir1_block = zalloc(blksz); 1567 if (ext4fs_indir1_block == NULL) { 1568 printf("** SI ext2fs read block (indir 1)" 1569 "malloc failed. **\n"); 1570 return -1; 1571 } 1572 ext4fs_indir1_size = blksz; 1573 ext4fs_indir1_blkno = -1; 1574 } 1575 if (blksz != ext4fs_indir1_size) { 1576 free(ext4fs_indir1_block); 1577 ext4fs_indir1_block = NULL; 1578 ext4fs_indir1_size = 0; 1579 ext4fs_indir1_blkno = -1; 1580 ext4fs_indir1_block = zalloc(blksz); 1581 if (ext4fs_indir1_block == NULL) { 1582 printf("** SI ext2fs read block (indir 1):" 1583 "malloc failed. **\n"); 1584 return -1; 1585 } 1586 ext4fs_indir1_size = blksz; 1587 } 1588 if ((__le32_to_cpu(inode->b.blocks.indir_block) << 1589 log2_blksz) != ext4fs_indir1_blkno) { 1590 status = 1591 ext4fs_devread((lbaint_t)__le32_to_cpu 1592 (inode->b.blocks. 1593 indir_block) << log2_blksz, 0, 1594 blksz, (char *)ext4fs_indir1_block); 1595 if (status == 0) { 1596 printf("** SI ext2fs read block (indir 1)" 1597 "failed. **\n"); 1598 return 0; 1599 } 1600 ext4fs_indir1_blkno = 1601 __le32_to_cpu(inode->b.blocks. 1602 indir_block) << log2_blksz; 1603 } 1604 blknr = __le32_to_cpu(ext4fs_indir1_block 1605 [fileblock - INDIRECT_BLOCKS]); 1606 } 1607 /* Double indirect. */ 1608 else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 * 1609 (blksz / 4 + 1)))) { 1610 1611 long int perblock = blksz / 4; 1612 long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4); 1613 1614 if (ext4fs_indir1_block == NULL) { 1615 ext4fs_indir1_block = zalloc(blksz); 1616 if (ext4fs_indir1_block == NULL) { 1617 printf("** DI ext2fs read block (indir 2 1)" 1618 "malloc failed. **\n"); 1619 return -1; 1620 } 1621 ext4fs_indir1_size = blksz; 1622 ext4fs_indir1_blkno = -1; 1623 } 1624 if (blksz != ext4fs_indir1_size) { 1625 free(ext4fs_indir1_block); 1626 ext4fs_indir1_block = NULL; 1627 ext4fs_indir1_size = 0; 1628 ext4fs_indir1_blkno = -1; 1629 ext4fs_indir1_block = zalloc(blksz); 1630 if (ext4fs_indir1_block == NULL) { 1631 printf("** DI ext2fs read block (indir 2 1)" 1632 "malloc failed. **\n"); 1633 return -1; 1634 } 1635 ext4fs_indir1_size = blksz; 1636 } 1637 if ((__le32_to_cpu(inode->b.blocks.double_indir_block) << 1638 log2_blksz) != ext4fs_indir1_blkno) { 1639 status = 1640 ext4fs_devread((lbaint_t)__le32_to_cpu 1641 (inode->b.blocks. 1642 double_indir_block) << log2_blksz, 1643 0, blksz, 1644 (char *)ext4fs_indir1_block); 1645 if (status == 0) { 1646 printf("** DI ext2fs read block (indir 2 1)" 1647 "failed. **\n"); 1648 return -1; 1649 } 1650 ext4fs_indir1_blkno = 1651 __le32_to_cpu(inode->b.blocks.double_indir_block) << 1652 log2_blksz; 1653 } 1654 1655 if (ext4fs_indir2_block == NULL) { 1656 ext4fs_indir2_block = zalloc(blksz); 1657 if (ext4fs_indir2_block == NULL) { 1658 printf("** DI ext2fs read block (indir 2 2)" 1659 "malloc failed. **\n"); 1660 return -1; 1661 } 1662 ext4fs_indir2_size = blksz; 1663 ext4fs_indir2_blkno = -1; 1664 } 1665 if (blksz != ext4fs_indir2_size) { 1666 free(ext4fs_indir2_block); 1667 ext4fs_indir2_block = NULL; 1668 ext4fs_indir2_size = 0; 1669 ext4fs_indir2_blkno = -1; 1670 ext4fs_indir2_block = zalloc(blksz); 1671 if (ext4fs_indir2_block == NULL) { 1672 printf("** DI ext2fs read block (indir 2 2)" 1673 "malloc failed. **\n"); 1674 return -1; 1675 } 1676 ext4fs_indir2_size = blksz; 1677 } 1678 if ((__le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) << 1679 log2_blksz) != ext4fs_indir2_blkno) { 1680 status = ext4fs_devread((lbaint_t)__le32_to_cpu 1681 (ext4fs_indir1_block 1682 [rblock / 1683 perblock]) << log2_blksz, 0, 1684 blksz, 1685 (char *)ext4fs_indir2_block); 1686 if (status == 0) { 1687 printf("** DI ext2fs read block (indir 2 2)" 1688 "failed. **\n"); 1689 return -1; 1690 } 1691 ext4fs_indir2_blkno = 1692 __le32_to_cpu(ext4fs_indir1_block[rblock 1693 / 1694 perblock]) << 1695 log2_blksz; 1696 } 1697 blknr = __le32_to_cpu(ext4fs_indir2_block[rblock % perblock]); 1698 } 1699 /* Tripple indirect. */ 1700 else { 1701 rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 + 1702 (blksz / 4 * blksz / 4)); 1703 perblock_child = blksz / 4; 1704 perblock_parent = ((blksz / 4) * (blksz / 4)); 1705 1706 if (ext4fs_indir1_block == NULL) { 1707 ext4fs_indir1_block = zalloc(blksz); 1708 if (ext4fs_indir1_block == NULL) { 1709 printf("** TI ext2fs read block (indir 2 1)" 1710 "malloc failed. **\n"); 1711 return -1; 1712 } 1713 ext4fs_indir1_size = blksz; 1714 ext4fs_indir1_blkno = -1; 1715 } 1716 if (blksz != ext4fs_indir1_size) { 1717 free(ext4fs_indir1_block); 1718 ext4fs_indir1_block = NULL; 1719 ext4fs_indir1_size = 0; 1720 ext4fs_indir1_blkno = -1; 1721 ext4fs_indir1_block = zalloc(blksz); 1722 if (ext4fs_indir1_block == NULL) { 1723 printf("** TI ext2fs read block (indir 2 1)" 1724 "malloc failed. **\n"); 1725 return -1; 1726 } 1727 ext4fs_indir1_size = blksz; 1728 } 1729 if ((__le32_to_cpu(inode->b.blocks.triple_indir_block) << 1730 log2_blksz) != ext4fs_indir1_blkno) { 1731 status = ext4fs_devread 1732 ((lbaint_t) 1733 __le32_to_cpu(inode->b.blocks.triple_indir_block) 1734 << log2_blksz, 0, blksz, 1735 (char *)ext4fs_indir1_block); 1736 if (status == 0) { 1737 printf("** TI ext2fs read block (indir 2 1)" 1738 "failed. **\n"); 1739 return -1; 1740 } 1741 ext4fs_indir1_blkno = 1742 __le32_to_cpu(inode->b.blocks.triple_indir_block) << 1743 log2_blksz; 1744 } 1745 1746 if (ext4fs_indir2_block == NULL) { 1747 ext4fs_indir2_block = zalloc(blksz); 1748 if (ext4fs_indir2_block == NULL) { 1749 printf("** TI ext2fs read block (indir 2 2)" 1750 "malloc failed. **\n"); 1751 return -1; 1752 } 1753 ext4fs_indir2_size = blksz; 1754 ext4fs_indir2_blkno = -1; 1755 } 1756 if (blksz != ext4fs_indir2_size) { 1757 free(ext4fs_indir2_block); 1758 ext4fs_indir2_block = NULL; 1759 ext4fs_indir2_size = 0; 1760 ext4fs_indir2_blkno = -1; 1761 ext4fs_indir2_block = zalloc(blksz); 1762 if (ext4fs_indir2_block == NULL) { 1763 printf("** TI ext2fs read block (indir 2 2)" 1764 "malloc failed. **\n"); 1765 return -1; 1766 } 1767 ext4fs_indir2_size = blksz; 1768 } 1769 if ((__le32_to_cpu(ext4fs_indir1_block[rblock / 1770 perblock_parent]) << 1771 log2_blksz) 1772 != ext4fs_indir2_blkno) { 1773 status = ext4fs_devread((lbaint_t)__le32_to_cpu 1774 (ext4fs_indir1_block 1775 [rblock / 1776 perblock_parent]) << 1777 log2_blksz, 0, blksz, 1778 (char *)ext4fs_indir2_block); 1779 if (status == 0) { 1780 printf("** TI ext2fs read block (indir 2 2)" 1781 "failed. **\n"); 1782 return -1; 1783 } 1784 ext4fs_indir2_blkno = 1785 __le32_to_cpu(ext4fs_indir1_block[rblock / 1786 perblock_parent]) 1787 << log2_blksz; 1788 } 1789 1790 if (ext4fs_indir3_block == NULL) { 1791 ext4fs_indir3_block = zalloc(blksz); 1792 if (ext4fs_indir3_block == NULL) { 1793 printf("** TI ext2fs read block (indir 2 2)" 1794 "malloc failed. **\n"); 1795 return -1; 1796 } 1797 ext4fs_indir3_size = blksz; 1798 ext4fs_indir3_blkno = -1; 1799 } 1800 if (blksz != ext4fs_indir3_size) { 1801 free(ext4fs_indir3_block); 1802 ext4fs_indir3_block = NULL; 1803 ext4fs_indir3_size = 0; 1804 ext4fs_indir3_blkno = -1; 1805 ext4fs_indir3_block = zalloc(blksz); 1806 if (ext4fs_indir3_block == NULL) { 1807 printf("** TI ext2fs read block (indir 2 2)" 1808 "malloc failed. **\n"); 1809 return -1; 1810 } 1811 ext4fs_indir3_size = blksz; 1812 } 1813 if ((__le32_to_cpu(ext4fs_indir2_block[rblock 1814 / 1815 perblock_child]) << 1816 log2_blksz) != ext4fs_indir3_blkno) { 1817 status = 1818 ext4fs_devread((lbaint_t)__le32_to_cpu 1819 (ext4fs_indir2_block 1820 [(rblock / perblock_child) 1821 % (blksz / 4)]) << log2_blksz, 0, 1822 blksz, (char *)ext4fs_indir3_block); 1823 if (status == 0) { 1824 printf("** TI ext2fs read block (indir 2 2)" 1825 "failed. **\n"); 1826 return -1; 1827 } 1828 ext4fs_indir3_blkno = 1829 __le32_to_cpu(ext4fs_indir2_block[(rblock / 1830 perblock_child) % 1831 (blksz / 1832 4)]) << 1833 log2_blksz; 1834 } 1835 1836 blknr = __le32_to_cpu(ext4fs_indir3_block 1837 [rblock % perblock_child]); 1838 } 1839 debug("read_allocated_block %ld\n", blknr); 1840 1841 return blknr; 1842 } 1843 1844 /** 1845 * ext4fs_reinit_global() - Reinitialize values of ext4 write implementation's 1846 * global pointers 1847 * 1848 * This function assures that for a file with the same name but different size 1849 * the sequential store on the ext4 filesystem will be correct. 1850 * 1851 * In this function the global data, responsible for internal representation 1852 * of the ext4 data are initialized to the reset state. Without this, during 1853 * replacement of the smaller file with the bigger truncation of new file was 1854 * performed. 1855 */ 1856 void ext4fs_reinit_global(void) 1857 { 1858 if (ext4fs_indir1_block != NULL) { 1859 free(ext4fs_indir1_block); 1860 ext4fs_indir1_block = NULL; 1861 ext4fs_indir1_size = 0; 1862 ext4fs_indir1_blkno = -1; 1863 } 1864 if (ext4fs_indir2_block != NULL) { 1865 free(ext4fs_indir2_block); 1866 ext4fs_indir2_block = NULL; 1867 ext4fs_indir2_size = 0; 1868 ext4fs_indir2_blkno = -1; 1869 } 1870 if (ext4fs_indir3_block != NULL) { 1871 free(ext4fs_indir3_block); 1872 ext4fs_indir3_block = NULL; 1873 ext4fs_indir3_size = 0; 1874 ext4fs_indir3_blkno = -1; 1875 } 1876 } 1877 void ext4fs_close(void) 1878 { 1879 if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) { 1880 ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen); 1881 ext4fs_file = NULL; 1882 } 1883 if (ext4fs_root != NULL) { 1884 free(ext4fs_root); 1885 ext4fs_root = NULL; 1886 } 1887 1888 ext4fs_reinit_global(); 1889 } 1890 1891 int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name, 1892 struct ext2fs_node **fnode, int *ftype) 1893 { 1894 unsigned int fpos = 0; 1895 int status; 1896 struct ext2fs_node *diro = (struct ext2fs_node *) dir; 1897 1898 #ifdef DEBUG 1899 if (name != NULL) 1900 printf("Iterate dir %s\n", name); 1901 #endif /* of DEBUG */ 1902 if (!diro->inode_read) { 1903 status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode); 1904 if (status == 0) 1905 return 0; 1906 } 1907 /* Search the file. */ 1908 while (fpos < __le32_to_cpu(diro->inode.size)) { 1909 struct ext2_dirent dirent; 1910 1911 status = ext4fs_read_file(diro, fpos, 1912 sizeof(struct ext2_dirent), 1913 (char *) &dirent); 1914 if (status < 1) 1915 return 0; 1916 1917 if (dirent.namelen != 0) { 1918 char filename[dirent.namelen + 1]; 1919 struct ext2fs_node *fdiro; 1920 int type = FILETYPE_UNKNOWN; 1921 1922 status = ext4fs_read_file(diro, 1923 fpos + 1924 sizeof(struct ext2_dirent), 1925 dirent.namelen, filename); 1926 if (status < 1) 1927 return 0; 1928 1929 fdiro = zalloc(sizeof(struct ext2fs_node)); 1930 if (!fdiro) 1931 return 0; 1932 1933 fdiro->data = diro->data; 1934 fdiro->ino = __le32_to_cpu(dirent.inode); 1935 1936 filename[dirent.namelen] = '\0'; 1937 1938 if (dirent.filetype != FILETYPE_UNKNOWN) { 1939 fdiro->inode_read = 0; 1940 1941 if (dirent.filetype == FILETYPE_DIRECTORY) 1942 type = FILETYPE_DIRECTORY; 1943 else if (dirent.filetype == FILETYPE_SYMLINK) 1944 type = FILETYPE_SYMLINK; 1945 else if (dirent.filetype == FILETYPE_REG) 1946 type = FILETYPE_REG; 1947 } else { 1948 status = ext4fs_read_inode(diro->data, 1949 __le32_to_cpu 1950 (dirent.inode), 1951 &fdiro->inode); 1952 if (status == 0) { 1953 free(fdiro); 1954 return 0; 1955 } 1956 fdiro->inode_read = 1; 1957 1958 if ((__le16_to_cpu(fdiro->inode.mode) & 1959 FILETYPE_INO_MASK) == 1960 FILETYPE_INO_DIRECTORY) { 1961 type = FILETYPE_DIRECTORY; 1962 } else if ((__le16_to_cpu(fdiro->inode.mode) 1963 & FILETYPE_INO_MASK) == 1964 FILETYPE_INO_SYMLINK) { 1965 type = FILETYPE_SYMLINK; 1966 } else if ((__le16_to_cpu(fdiro->inode.mode) 1967 & FILETYPE_INO_MASK) == 1968 FILETYPE_INO_REG) { 1969 type = FILETYPE_REG; 1970 } 1971 } 1972 #ifdef DEBUG 1973 printf("iterate >%s<\n", filename); 1974 #endif /* of DEBUG */ 1975 if ((name != NULL) && (fnode != NULL) 1976 && (ftype != NULL)) { 1977 if (strcmp(filename, name) == 0) { 1978 *ftype = type; 1979 *fnode = fdiro; 1980 return 1; 1981 } 1982 } else { 1983 if (fdiro->inode_read == 0) { 1984 status = ext4fs_read_inode(diro->data, 1985 __le32_to_cpu( 1986 dirent.inode), 1987 &fdiro->inode); 1988 if (status == 0) { 1989 free(fdiro); 1990 return 0; 1991 } 1992 fdiro->inode_read = 1; 1993 } 1994 switch (type) { 1995 case FILETYPE_DIRECTORY: 1996 printf("<DIR> "); 1997 break; 1998 case FILETYPE_SYMLINK: 1999 printf("<SYM> "); 2000 break; 2001 case FILETYPE_REG: 2002 printf(" "); 2003 break; 2004 default: 2005 printf("< ? > "); 2006 break; 2007 } 2008 printf("%10d %s\n", 2009 __le32_to_cpu(fdiro->inode.size), 2010 filename); 2011 } 2012 free(fdiro); 2013 } 2014 fpos += __le16_to_cpu(dirent.direntlen); 2015 } 2016 return 0; 2017 } 2018 2019 static char *ext4fs_read_symlink(struct ext2fs_node *node) 2020 { 2021 char *symlink; 2022 struct ext2fs_node *diro = node; 2023 int status; 2024 2025 if (!diro->inode_read) { 2026 status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode); 2027 if (status == 0) 2028 return 0; 2029 } 2030 symlink = zalloc(__le32_to_cpu(diro->inode.size) + 1); 2031 if (!symlink) 2032 return 0; 2033 2034 if (__le32_to_cpu(diro->inode.size) <= 60) { 2035 strncpy(symlink, diro->inode.b.symlink, 2036 __le32_to_cpu(diro->inode.size)); 2037 } else { 2038 status = ext4fs_read_file(diro, 0, 2039 __le32_to_cpu(diro->inode.size), 2040 symlink); 2041 if (status == 0) { 2042 free(symlink); 2043 return 0; 2044 } 2045 } 2046 symlink[__le32_to_cpu(diro->inode.size)] = '\0'; 2047 return symlink; 2048 } 2049 2050 static int ext4fs_find_file1(const char *currpath, 2051 struct ext2fs_node *currroot, 2052 struct ext2fs_node **currfound, int *foundtype) 2053 { 2054 char fpath[strlen(currpath) + 1]; 2055 char *name = fpath; 2056 char *next; 2057 int status; 2058 int type = FILETYPE_DIRECTORY; 2059 struct ext2fs_node *currnode = currroot; 2060 struct ext2fs_node *oldnode = currroot; 2061 2062 strncpy(fpath, currpath, strlen(currpath) + 1); 2063 2064 /* Remove all leading slashes. */ 2065 while (*name == '/') 2066 name++; 2067 2068 if (!*name) { 2069 *currfound = currnode; 2070 return 1; 2071 } 2072 2073 for (;;) { 2074 int found; 2075 2076 /* Extract the actual part from the pathname. */ 2077 next = strchr(name, '/'); 2078 if (next) { 2079 /* Remove all leading slashes. */ 2080 while (*next == '/') 2081 *(next++) = '\0'; 2082 } 2083 2084 if (type != FILETYPE_DIRECTORY) { 2085 ext4fs_free_node(currnode, currroot); 2086 return 0; 2087 } 2088 2089 oldnode = currnode; 2090 2091 /* Iterate over the directory. */ 2092 found = ext4fs_iterate_dir(currnode, name, &currnode, &type); 2093 if (found == 0) 2094 return 0; 2095 2096 if (found == -1) 2097 break; 2098 2099 /* Read in the symlink and follow it. */ 2100 if (type == FILETYPE_SYMLINK) { 2101 char *symlink; 2102 2103 /* Test if the symlink does not loop. */ 2104 if (++symlinknest == 8) { 2105 ext4fs_free_node(currnode, currroot); 2106 ext4fs_free_node(oldnode, currroot); 2107 return 0; 2108 } 2109 2110 symlink = ext4fs_read_symlink(currnode); 2111 ext4fs_free_node(currnode, currroot); 2112 2113 if (!symlink) { 2114 ext4fs_free_node(oldnode, currroot); 2115 return 0; 2116 } 2117 2118 debug("Got symlink >%s<\n", symlink); 2119 2120 if (symlink[0] == '/') { 2121 ext4fs_free_node(oldnode, currroot); 2122 oldnode = &ext4fs_root->diropen; 2123 } 2124 2125 /* Lookup the node the symlink points to. */ 2126 status = ext4fs_find_file1(symlink, oldnode, 2127 &currnode, &type); 2128 2129 free(symlink); 2130 2131 if (status == 0) { 2132 ext4fs_free_node(oldnode, currroot); 2133 return 0; 2134 } 2135 } 2136 2137 ext4fs_free_node(oldnode, currroot); 2138 2139 /* Found the node! */ 2140 if (!next || *next == '\0') { 2141 *currfound = currnode; 2142 *foundtype = type; 2143 return 1; 2144 } 2145 name = next; 2146 } 2147 return -1; 2148 } 2149 2150 int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode, 2151 struct ext2fs_node **foundnode, int expecttype) 2152 { 2153 int status; 2154 int foundtype = FILETYPE_DIRECTORY; 2155 2156 symlinknest = 0; 2157 if (!path) 2158 return 0; 2159 2160 status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype); 2161 if (status == 0) 2162 return 0; 2163 2164 /* Check if the node that was found was of the expected type. */ 2165 if ((expecttype == FILETYPE_REG) && (foundtype != expecttype)) 2166 return 0; 2167 else if ((expecttype == FILETYPE_DIRECTORY) 2168 && (foundtype != expecttype)) 2169 return 0; 2170 2171 return 1; 2172 } 2173 2174 int ext4fs_open(const char *filename) 2175 { 2176 struct ext2fs_node *fdiro = NULL; 2177 int status; 2178 int len; 2179 2180 if (ext4fs_root == NULL) 2181 return -1; 2182 2183 ext4fs_file = NULL; 2184 status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro, 2185 FILETYPE_REG); 2186 if (status == 0) 2187 goto fail; 2188 2189 if (!fdiro->inode_read) { 2190 status = ext4fs_read_inode(fdiro->data, fdiro->ino, 2191 &fdiro->inode); 2192 if (status == 0) 2193 goto fail; 2194 } 2195 len = __le32_to_cpu(fdiro->inode.size); 2196 ext4fs_file = fdiro; 2197 2198 return len; 2199 fail: 2200 ext4fs_free_node(fdiro, &ext4fs_root->diropen); 2201 2202 return -1; 2203 } 2204 2205 int ext4fs_mount(unsigned part_length) 2206 { 2207 struct ext2_data *data; 2208 int status; 2209 struct ext_filesystem *fs = get_fs(); 2210 data = zalloc(SUPERBLOCK_SIZE); 2211 if (!data) 2212 return 0; 2213 2214 /* Read the superblock. */ 2215 status = ext4_read_superblock((char *)&data->sblock); 2216 2217 if (status == 0) 2218 goto fail; 2219 2220 /* Make sure this is an ext2 filesystem. */ 2221 if (__le16_to_cpu(data->sblock.magic) != EXT2_MAGIC) 2222 goto fail; 2223 2224 if (__le32_to_cpu(data->sblock.revision_level == 0)) 2225 fs->inodesz = 128; 2226 else 2227 fs->inodesz = __le16_to_cpu(data->sblock.inode_size); 2228 2229 debug("EXT2 rev %d, inode_size %d\n", 2230 __le32_to_cpu(data->sblock.revision_level), fs->inodesz); 2231 2232 data->diropen.data = data; 2233 data->diropen.ino = 2; 2234 data->diropen.inode_read = 1; 2235 data->inode = &data->diropen.inode; 2236 2237 status = ext4fs_read_inode(data, 2, data->inode); 2238 if (status == 0) 2239 goto fail; 2240 2241 ext4fs_root = data; 2242 2243 return 1; 2244 fail: 2245 printf("Failed to mount ext2 filesystem...\n"); 2246 free(data); 2247 ext4fs_root = NULL; 2248 2249 return 0; 2250 } 2251