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 uint32_t *ext4fs_indir1_block; 37 int ext4fs_indir1_size; 38 int ext4fs_indir1_blkno = -1; 39 uint32_t *ext4fs_indir2_block; 40 int ext4fs_indir2_size; 41 int ext4fs_indir2_blkno = -1; 42 43 uint32_t *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 uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n) 51 { 52 uint32_t res = size / n; 53 if (res * n != size) 54 res++; 55 56 return res; 57 } 58 59 void put_ext4(uint64_t off, void *buf, uint32_t size) 60 { 61 uint64_t startblock; 62 uint64_t remainder; 63 unsigned char *temp_ptr = NULL; 64 struct ext_filesystem *fs = get_fs(); 65 int log2blksz = fs->dev_desc->log2blksz; 66 ALLOC_CACHE_ALIGN_BUFFER(unsigned char, sec_buf, fs->dev_desc->blksz); 67 68 startblock = off >> log2blksz; 69 startblock += part_offset; 70 remainder = off & (uint64_t)(fs->dev_desc->blksz - 1); 71 72 if (fs->dev_desc == NULL) 73 return; 74 75 if ((startblock + (size >> log2blksz)) > 76 (part_offset + fs->total_sect)) { 77 printf("part_offset is " LBAFU "\n", part_offset); 78 printf("total_sector is %" PRIu64 "\n", fs->total_sect); 79 printf("error: overflow occurs\n"); 80 return; 81 } 82 83 if (remainder) { 84 if (fs->dev_desc->block_read) { 85 fs->dev_desc->block_read(fs->dev_desc->dev, 86 startblock, 1, sec_buf); 87 temp_ptr = sec_buf; 88 memcpy((temp_ptr + remainder), 89 (unsigned char *)buf, size); 90 fs->dev_desc->block_write(fs->dev_desc->dev, 91 startblock, 1, sec_buf); 92 } 93 } else { 94 if (size >> log2blksz != 0) { 95 fs->dev_desc->block_write(fs->dev_desc->dev, 96 startblock, 97 size >> log2blksz, 98 (unsigned long *)buf); 99 } else { 100 fs->dev_desc->block_read(fs->dev_desc->dev, 101 startblock, 1, sec_buf); 102 temp_ptr = sec_buf; 103 memcpy(temp_ptr, buf, size); 104 fs->dev_desc->block_write(fs->dev_desc->dev, 105 startblock, 1, 106 (unsigned long *)sec_buf); 107 } 108 } 109 } 110 111 static int _get_new_inode_no(unsigned char *buffer) 112 { 113 struct ext_filesystem *fs = get_fs(); 114 unsigned char input; 115 int operand, status; 116 int count = 1; 117 int j = 0; 118 119 /* get the blocksize of the filesystem */ 120 unsigned char *ptr = buffer; 121 while (*ptr == 255) { 122 ptr++; 123 count += 8; 124 if (count > ext4fs_root->sblock.inodes_per_group) 125 return -1; 126 } 127 128 for (j = 0; j < fs->blksz; j++) { 129 input = *ptr; 130 int i = 0; 131 while (i <= 7) { 132 operand = 1 << i; 133 status = input & operand; 134 if (status) { 135 i++; 136 count++; 137 } else { 138 *ptr |= operand; 139 return count; 140 } 141 } 142 ptr = ptr + 1; 143 } 144 145 return -1; 146 } 147 148 static int _get_new_blk_no(unsigned char *buffer) 149 { 150 unsigned char input; 151 int operand, status; 152 int count = 0; 153 int j = 0; 154 unsigned char *ptr = buffer; 155 struct ext_filesystem *fs = get_fs(); 156 157 if (fs->blksz != 1024) 158 count = 0; 159 else 160 count = 1; 161 162 while (*ptr == 255) { 163 ptr++; 164 count += 8; 165 if (count == (fs->blksz * 8)) 166 return -1; 167 } 168 169 for (j = 0; j < fs->blksz; j++) { 170 input = *ptr; 171 int i = 0; 172 while (i <= 7) { 173 operand = 1 << i; 174 status = input & operand; 175 if (status) { 176 i++; 177 count++; 178 } else { 179 *ptr |= operand; 180 return count; 181 } 182 } 183 ptr = ptr + 1; 184 } 185 186 return -1; 187 } 188 189 int ext4fs_set_block_bmap(long int blockno, unsigned char *buffer, int index) 190 { 191 int i, remainder, status; 192 unsigned char *ptr = buffer; 193 unsigned char operand; 194 i = blockno / 8; 195 remainder = blockno % 8; 196 int blocksize = EXT2_BLOCK_SIZE(ext4fs_root); 197 198 i = i - (index * blocksize); 199 if (blocksize != 1024) { 200 ptr = ptr + i; 201 operand = 1 << remainder; 202 status = *ptr & operand; 203 if (status) 204 return -1; 205 206 *ptr = *ptr | operand; 207 return 0; 208 } else { 209 if (remainder == 0) { 210 ptr = ptr + i - 1; 211 operand = (1 << 7); 212 } else { 213 ptr = ptr + i; 214 operand = (1 << (remainder - 1)); 215 } 216 status = *ptr & operand; 217 if (status) 218 return -1; 219 220 *ptr = *ptr | operand; 221 return 0; 222 } 223 } 224 225 void ext4fs_reset_block_bmap(long int blockno, unsigned char *buffer, int index) 226 { 227 int i, remainder, status; 228 unsigned char *ptr = buffer; 229 unsigned char operand; 230 i = blockno / 8; 231 remainder = blockno % 8; 232 int blocksize = EXT2_BLOCK_SIZE(ext4fs_root); 233 234 i = i - (index * blocksize); 235 if (blocksize != 1024) { 236 ptr = ptr + i; 237 operand = (1 << remainder); 238 status = *ptr & operand; 239 if (status) 240 *ptr = *ptr & ~(operand); 241 } else { 242 if (remainder == 0) { 243 ptr = ptr + i - 1; 244 operand = (1 << 7); 245 } else { 246 ptr = ptr + i; 247 operand = (1 << (remainder - 1)); 248 } 249 status = *ptr & operand; 250 if (status) 251 *ptr = *ptr & ~(operand); 252 } 253 } 254 255 int ext4fs_set_inode_bmap(int inode_no, unsigned char *buffer, int index) 256 { 257 int i, remainder, status; 258 unsigned char *ptr = buffer; 259 unsigned char operand; 260 261 inode_no -= (index * ext4fs_root->sblock.inodes_per_group); 262 i = inode_no / 8; 263 remainder = inode_no % 8; 264 if (remainder == 0) { 265 ptr = ptr + i - 1; 266 operand = (1 << 7); 267 } else { 268 ptr = ptr + i; 269 operand = (1 << (remainder - 1)); 270 } 271 status = *ptr & operand; 272 if (status) 273 return -1; 274 275 *ptr = *ptr | operand; 276 277 return 0; 278 } 279 280 void ext4fs_reset_inode_bmap(int inode_no, unsigned char *buffer, int index) 281 { 282 int i, remainder, status; 283 unsigned char *ptr = buffer; 284 unsigned char operand; 285 286 inode_no -= (index * ext4fs_root->sblock.inodes_per_group); 287 i = inode_no / 8; 288 remainder = inode_no % 8; 289 if (remainder == 0) { 290 ptr = ptr + i - 1; 291 operand = (1 << 7); 292 } else { 293 ptr = ptr + i; 294 operand = (1 << (remainder - 1)); 295 } 296 status = *ptr & operand; 297 if (status) 298 *ptr = *ptr & ~(operand); 299 } 300 301 int ext4fs_checksum_update(unsigned int i) 302 { 303 struct ext2_block_group *desc; 304 struct ext_filesystem *fs = get_fs(); 305 __u16 crc = 0; 306 307 desc = (struct ext2_block_group *)&fs->bgd[i]; 308 if (fs->sb->feature_ro_compat & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) { 309 int offset = offsetof(struct ext2_block_group, bg_checksum); 310 311 crc = ext2fs_crc16(~0, fs->sb->unique_id, 312 sizeof(fs->sb->unique_id)); 313 crc = ext2fs_crc16(crc, &i, sizeof(i)); 314 crc = ext2fs_crc16(crc, desc, offset); 315 offset += sizeof(desc->bg_checksum); /* skip checksum */ 316 assert(offset == sizeof(*desc)); 317 } 318 319 return crc; 320 } 321 322 static int check_void_in_dentry(struct ext2_dirent *dir, char *filename) 323 { 324 int dentry_length; 325 int sizeof_void_space; 326 int new_entry_byte_reqd; 327 short padding_factor = 0; 328 329 if (dir->namelen % 4 != 0) 330 padding_factor = 4 - (dir->namelen % 4); 331 332 dentry_length = sizeof(struct ext2_dirent) + 333 dir->namelen + padding_factor; 334 sizeof_void_space = dir->direntlen - dentry_length; 335 if (sizeof_void_space == 0) 336 return 0; 337 338 padding_factor = 0; 339 if (strlen(filename) % 4 != 0) 340 padding_factor = 4 - (strlen(filename) % 4); 341 342 new_entry_byte_reqd = strlen(filename) + 343 sizeof(struct ext2_dirent) + padding_factor; 344 if (sizeof_void_space >= new_entry_byte_reqd) { 345 dir->direntlen = dentry_length; 346 return sizeof_void_space; 347 } 348 349 return 0; 350 } 351 352 void ext4fs_update_parent_dentry(char *filename, int *p_ino, int file_type) 353 { 354 unsigned int *zero_buffer = NULL; 355 char *root_first_block_buffer = NULL; 356 int direct_blk_idx; 357 long int root_blknr; 358 long int first_block_no_of_root = 0; 359 long int previous_blknr = -1; 360 int totalbytes = 0; 361 short int padding_factor = 0; 362 unsigned int new_entry_byte_reqd; 363 unsigned int last_entry_dirlen; 364 int sizeof_void_space = 0; 365 int templength = 0; 366 int inodeno; 367 int status; 368 struct ext_filesystem *fs = get_fs(); 369 /* directory entry */ 370 struct ext2_dirent *dir; 371 char *temp_dir = NULL; 372 373 zero_buffer = zalloc(fs->blksz); 374 if (!zero_buffer) { 375 printf("No Memory\n"); 376 return; 377 } 378 root_first_block_buffer = zalloc(fs->blksz); 379 if (!root_first_block_buffer) { 380 free(zero_buffer); 381 printf("No Memory\n"); 382 return; 383 } 384 restart: 385 386 /* read the block no allocated to a file */ 387 for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS; 388 direct_blk_idx++) { 389 root_blknr = read_allocated_block(g_parent_inode, 390 direct_blk_idx); 391 if (root_blknr == 0) { 392 first_block_no_of_root = previous_blknr; 393 break; 394 } 395 previous_blknr = root_blknr; 396 } 397 398 status = ext4fs_devread((lbaint_t)first_block_no_of_root 399 * fs->sect_perblk, 400 0, fs->blksz, root_first_block_buffer); 401 if (status == 0) 402 goto fail; 403 404 if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root)) 405 goto fail; 406 dir = (struct ext2_dirent *)root_first_block_buffer; 407 totalbytes = 0; 408 while (dir->direntlen > 0) { 409 /* 410 * blocksize-totalbytes because last directory length 411 * i.e. dir->direntlen is free availble space in the 412 * block that means it is a last entry of directory 413 * entry 414 */ 415 416 /* traversing the each directory entry */ 417 if (fs->blksz - totalbytes == dir->direntlen) { 418 if (strlen(filename) % 4 != 0) 419 padding_factor = 4 - (strlen(filename) % 4); 420 421 new_entry_byte_reqd = strlen(filename) + 422 sizeof(struct ext2_dirent) + padding_factor; 423 padding_factor = 0; 424 /* 425 * update last directory entry length to its 426 * length because we are creating new directory 427 * entry 428 */ 429 if (dir->namelen % 4 != 0) 430 padding_factor = 4 - (dir->namelen % 4); 431 432 last_entry_dirlen = dir->namelen + 433 sizeof(struct ext2_dirent) + padding_factor; 434 if ((fs->blksz - totalbytes - last_entry_dirlen) < 435 new_entry_byte_reqd) { 436 printf("1st Block Full:Allocate new block\n"); 437 438 if (direct_blk_idx == INDIRECT_BLOCKS - 1) { 439 printf("Directory exceeds limit\n"); 440 goto fail; 441 } 442 g_parent_inode->b.blocks.dir_blocks 443 [direct_blk_idx] = ext4fs_get_new_blk_no(); 444 if (g_parent_inode->b.blocks.dir_blocks 445 [direct_blk_idx] == -1) { 446 printf("no block left to assign\n"); 447 goto fail; 448 } 449 put_ext4(((uint64_t) 450 ((uint64_t)g_parent_inode->b. 451 blocks.dir_blocks[direct_blk_idx] * 452 (uint64_t)fs->blksz)), zero_buffer, fs->blksz); 453 g_parent_inode->size = 454 g_parent_inode->size + fs->blksz; 455 g_parent_inode->blockcnt = 456 g_parent_inode->blockcnt + fs->sect_perblk; 457 if (ext4fs_put_metadata 458 (root_first_block_buffer, 459 first_block_no_of_root)) 460 goto fail; 461 goto restart; 462 } 463 dir->direntlen = last_entry_dirlen; 464 break; 465 } 466 467 templength = dir->direntlen; 468 totalbytes = totalbytes + templength; 469 sizeof_void_space = check_void_in_dentry(dir, filename); 470 if (sizeof_void_space) 471 break; 472 473 dir = (struct ext2_dirent *)((char *)dir + templength); 474 } 475 476 /* make a pointer ready for creating next directory entry */ 477 templength = dir->direntlen; 478 totalbytes = totalbytes + templength; 479 dir = (struct ext2_dirent *)((char *)dir + templength); 480 481 /* get the next available inode number */ 482 inodeno = ext4fs_get_new_inode_no(); 483 if (inodeno == -1) { 484 printf("no inode left to assign\n"); 485 goto fail; 486 } 487 dir->inode = inodeno; 488 if (sizeof_void_space) 489 dir->direntlen = sizeof_void_space; 490 else 491 dir->direntlen = fs->blksz - totalbytes; 492 493 dir->namelen = strlen(filename); 494 dir->filetype = FILETYPE_REG; /* regular file */ 495 temp_dir = (char *)dir; 496 temp_dir = temp_dir + sizeof(struct ext2_dirent); 497 memcpy(temp_dir, filename, strlen(filename)); 498 499 *p_ino = inodeno; 500 501 /* update or write the 1st block of root inode */ 502 if (ext4fs_put_metadata(root_first_block_buffer, 503 first_block_no_of_root)) 504 goto fail; 505 506 fail: 507 free(zero_buffer); 508 free(root_first_block_buffer); 509 } 510 511 static int search_dir(struct ext2_inode *parent_inode, char *dirname) 512 { 513 int status; 514 int inodeno; 515 int totalbytes; 516 int templength; 517 int direct_blk_idx; 518 long int blknr; 519 int found = 0; 520 char *ptr = NULL; 521 unsigned char *block_buffer = NULL; 522 struct ext2_dirent *dir = NULL; 523 struct ext2_dirent *previous_dir = NULL; 524 struct ext_filesystem *fs = get_fs(); 525 526 /* read the block no allocated to a file */ 527 for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS; 528 direct_blk_idx++) { 529 blknr = read_allocated_block(parent_inode, direct_blk_idx); 530 if (blknr == 0) 531 goto fail; 532 533 /* read the blocks of parenet inode */ 534 block_buffer = zalloc(fs->blksz); 535 if (!block_buffer) 536 goto fail; 537 538 status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk, 539 0, fs->blksz, (char *)block_buffer); 540 if (status == 0) 541 goto fail; 542 543 dir = (struct ext2_dirent *)block_buffer; 544 ptr = (char *)dir; 545 totalbytes = 0; 546 while (dir->direntlen >= 0) { 547 /* 548 * blocksize-totalbytes because last directory 549 * length i.e.,*dir->direntlen is free availble 550 * space in the block that means 551 * it is a last entry of directory entry 552 */ 553 if (strlen(dirname) == dir->namelen) { 554 if (strncmp(dirname, ptr + 555 sizeof(struct ext2_dirent), 556 dir->namelen) == 0) { 557 previous_dir->direntlen += 558 dir->direntlen; 559 inodeno = dir->inode; 560 dir->inode = 0; 561 found = 1; 562 break; 563 } 564 } 565 566 if (fs->blksz - totalbytes == dir->direntlen) 567 break; 568 569 /* traversing the each directory entry */ 570 templength = dir->direntlen; 571 totalbytes = totalbytes + templength; 572 previous_dir = dir; 573 dir = (struct ext2_dirent *)((char *)dir + templength); 574 ptr = (char *)dir; 575 } 576 577 if (found == 1) { 578 free(block_buffer); 579 block_buffer = NULL; 580 return inodeno; 581 } 582 583 free(block_buffer); 584 block_buffer = NULL; 585 } 586 587 fail: 588 free(block_buffer); 589 590 return -1; 591 } 592 593 static int find_dir_depth(char *dirname) 594 { 595 char *token = strtok(dirname, "/"); 596 int count = 0; 597 while (token != NULL) { 598 token = strtok(NULL, "/"); 599 count++; 600 } 601 return count + 1 + 1; 602 /* 603 * for example for string /home/temp 604 * depth=home(1)+temp(1)+1 extra for NULL; 605 * so count is 4; 606 */ 607 } 608 609 static int parse_path(char **arr, char *dirname) 610 { 611 char *token = strtok(dirname, "/"); 612 int i = 0; 613 614 /* add root */ 615 arr[i] = zalloc(strlen("/") + 1); 616 if (!arr[i]) 617 return -ENOMEM; 618 619 arr[i++] = "/"; 620 621 /* add each path entry after root */ 622 while (token != NULL) { 623 arr[i] = zalloc(strlen(token) + 1); 624 if (!arr[i]) 625 return -ENOMEM; 626 memcpy(arr[i++], token, strlen(token)); 627 token = strtok(NULL, "/"); 628 } 629 arr[i] = NULL; 630 631 return 0; 632 } 633 634 int ext4fs_iget(int inode_no, struct ext2_inode *inode) 635 { 636 if (ext4fs_read_inode(ext4fs_root, inode_no, inode) == 0) 637 return -1; 638 639 return 0; 640 } 641 642 /* 643 * Function: ext4fs_get_parent_inode_num 644 * Return Value: inode Number of the parent directory of file/Directory to be 645 * created 646 * dirname : Input parmater, input path name of the file/directory to be created 647 * dname : Output parameter, to be filled with the name of the directory 648 * extracted from dirname 649 */ 650 int ext4fs_get_parent_inode_num(const char *dirname, char *dname, int flags) 651 { 652 int i; 653 int depth = 0; 654 int matched_inode_no; 655 int result_inode_no = -1; 656 char **ptr = NULL; 657 char *depth_dirname = NULL; 658 char *parse_dirname = NULL; 659 struct ext2_inode *parent_inode = NULL; 660 struct ext2_inode *first_inode = NULL; 661 struct ext2_inode temp_inode; 662 663 if (*dirname != '/') { 664 printf("Please supply Absolute path\n"); 665 return -1; 666 } 667 668 /* TODO: input validation make equivalent to linux */ 669 depth_dirname = zalloc(strlen(dirname) + 1); 670 if (!depth_dirname) 671 return -ENOMEM; 672 673 memcpy(depth_dirname, dirname, strlen(dirname)); 674 depth = find_dir_depth(depth_dirname); 675 parse_dirname = zalloc(strlen(dirname) + 1); 676 if (!parse_dirname) 677 goto fail; 678 memcpy(parse_dirname, dirname, strlen(dirname)); 679 680 /* allocate memory for each directory level */ 681 ptr = zalloc((depth) * sizeof(char *)); 682 if (!ptr) 683 goto fail; 684 if (parse_path(ptr, parse_dirname)) 685 goto fail; 686 parent_inode = zalloc(sizeof(struct ext2_inode)); 687 if (!parent_inode) 688 goto fail; 689 first_inode = zalloc(sizeof(struct ext2_inode)); 690 if (!first_inode) 691 goto fail; 692 memcpy(parent_inode, ext4fs_root->inode, sizeof(struct ext2_inode)); 693 memcpy(first_inode, parent_inode, sizeof(struct ext2_inode)); 694 if (flags & F_FILE) 695 result_inode_no = EXT2_ROOT_INO; 696 for (i = 1; i < depth; i++) { 697 matched_inode_no = search_dir(parent_inode, ptr[i]); 698 if (matched_inode_no == -1) { 699 if (ptr[i + 1] == NULL && i == 1) { 700 result_inode_no = EXT2_ROOT_INO; 701 goto end; 702 } else { 703 if (ptr[i + 1] == NULL) 704 break; 705 printf("Invalid path\n"); 706 result_inode_no = -1; 707 goto fail; 708 } 709 } else { 710 if (ptr[i + 1] != NULL) { 711 memset(parent_inode, '\0', 712 sizeof(struct ext2_inode)); 713 if (ext4fs_iget(matched_inode_no, 714 parent_inode)) { 715 result_inode_no = -1; 716 goto fail; 717 } 718 result_inode_no = matched_inode_no; 719 } else { 720 break; 721 } 722 } 723 } 724 725 end: 726 if (i == 1) 727 matched_inode_no = search_dir(first_inode, ptr[i]); 728 else 729 matched_inode_no = search_dir(parent_inode, ptr[i]); 730 731 if (matched_inode_no != -1) { 732 ext4fs_iget(matched_inode_no, &temp_inode); 733 if (temp_inode.mode & S_IFDIR) { 734 printf("It is a Directory\n"); 735 result_inode_no = -1; 736 goto fail; 737 } 738 } 739 740 if (strlen(ptr[i]) > 256) { 741 result_inode_no = -1; 742 goto fail; 743 } 744 memcpy(dname, ptr[i], strlen(ptr[i])); 745 746 fail: 747 free(depth_dirname); 748 free(parse_dirname); 749 free(ptr); 750 free(parent_inode); 751 free(first_inode); 752 753 return result_inode_no; 754 } 755 756 static int check_filename(char *filename, unsigned int blknr) 757 { 758 unsigned int first_block_no_of_root; 759 int totalbytes = 0; 760 int templength = 0; 761 int status, inodeno; 762 int found = 0; 763 char *root_first_block_buffer = NULL; 764 char *root_first_block_addr = NULL; 765 struct ext2_dirent *dir = NULL; 766 struct ext2_dirent *previous_dir = NULL; 767 char *ptr = NULL; 768 struct ext_filesystem *fs = get_fs(); 769 770 /* get the first block of root */ 771 first_block_no_of_root = blknr; 772 root_first_block_buffer = zalloc(fs->blksz); 773 if (!root_first_block_buffer) 774 return -ENOMEM; 775 root_first_block_addr = root_first_block_buffer; 776 status = ext4fs_devread((lbaint_t)first_block_no_of_root * 777 fs->sect_perblk, 0, 778 fs->blksz, root_first_block_buffer); 779 if (status == 0) 780 goto fail; 781 782 if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root)) 783 goto fail; 784 dir = (struct ext2_dirent *)root_first_block_buffer; 785 ptr = (char *)dir; 786 totalbytes = 0; 787 while (dir->direntlen >= 0) { 788 /* 789 * blocksize-totalbytes because last 790 * directory length i.e., *dir->direntlen 791 * is free availble space in the block that 792 * means it is a last entry of directory entry 793 */ 794 if (strlen(filename) == dir->namelen) { 795 if (strncmp(filename, ptr + sizeof(struct ext2_dirent), 796 dir->namelen) == 0) { 797 printf("file found deleting\n"); 798 previous_dir->direntlen += dir->direntlen; 799 inodeno = dir->inode; 800 dir->inode = 0; 801 found = 1; 802 break; 803 } 804 } 805 806 if (fs->blksz - totalbytes == dir->direntlen) 807 break; 808 809 /* traversing the each directory entry */ 810 templength = dir->direntlen; 811 totalbytes = totalbytes + templength; 812 previous_dir = dir; 813 dir = (struct ext2_dirent *)((char *)dir + templength); 814 ptr = (char *)dir; 815 } 816 817 818 if (found == 1) { 819 if (ext4fs_put_metadata(root_first_block_addr, 820 first_block_no_of_root)) 821 goto fail; 822 return inodeno; 823 } 824 fail: 825 free(root_first_block_buffer); 826 827 return -1; 828 } 829 830 int ext4fs_filename_check(char *filename) 831 { 832 short direct_blk_idx = 0; 833 long int blknr = -1; 834 int inodeno = -1; 835 836 /* read the block no allocated to a file */ 837 for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS; 838 direct_blk_idx++) { 839 blknr = read_allocated_block(g_parent_inode, direct_blk_idx); 840 if (blknr == 0) 841 break; 842 inodeno = check_filename(filename, blknr); 843 if (inodeno != -1) 844 return inodeno; 845 } 846 847 return -1; 848 } 849 850 long int ext4fs_get_new_blk_no(void) 851 { 852 short i; 853 short status; 854 int remainder; 855 unsigned int bg_idx; 856 static int prev_bg_bitmap_index = -1; 857 unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group; 858 struct ext_filesystem *fs = get_fs(); 859 char *journal_buffer = zalloc(fs->blksz); 860 char *zero_buffer = zalloc(fs->blksz); 861 if (!journal_buffer || !zero_buffer) 862 goto fail; 863 struct ext2_block_group *bgd = (struct ext2_block_group *)fs->gdtable; 864 865 if (fs->first_pass_bbmap == 0) { 866 for (i = 0; i < fs->no_blkgrp; i++) { 867 if (bgd[i].free_blocks) { 868 if (bgd[i].bg_flags & EXT4_BG_BLOCK_UNINIT) { 869 put_ext4(((uint64_t) ((uint64_t)bgd[i].block_id * 870 (uint64_t)fs->blksz)), 871 zero_buffer, fs->blksz); 872 bgd[i].bg_flags = 873 bgd[i]. 874 bg_flags & ~EXT4_BG_BLOCK_UNINIT; 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 bgd[i].free_blocks--; 887 fs->sb->free_blocks--; 888 status = ext4fs_devread((lbaint_t) 889 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 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 (bgd[bg_idx].bg_flags & EXT4_BG_BLOCK_UNINIT) { 931 memset(zero_buffer, '\0', fs->blksz); 932 put_ext4(((uint64_t) ((uint64_t)bgd[bg_idx].block_id * 933 (uint64_t)fs->blksz)), zero_buffer, fs->blksz); 934 memcpy(fs->blk_bmaps[bg_idx], zero_buffer, fs->blksz); 935 bgd[bg_idx].bg_flags = bgd[bg_idx].bg_flags & 936 ~EXT4_BG_BLOCK_UNINIT; 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 memset(journal_buffer, '\0', fs->blksz); 949 status = ext4fs_devread((lbaint_t)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 bgd[bg_idx].block_id)) 956 goto fail; 957 958 prev_bg_bitmap_index = bg_idx; 959 } 960 bgd[bg_idx].free_blocks--; 961 fs->sb->free_blocks--; 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 = 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; 989 990 if (fs->first_pass_ibmap == 0) { 991 for (i = 0; i < fs->no_blkgrp; i++) { 992 if (bgd[i].free_inodes) { 993 if (bgd[i].bg_itable_unused != 994 bgd[i].free_inodes) 995 bgd[i].bg_itable_unused = 996 bgd[i].free_inodes; 997 if (bgd[i].bg_flags & EXT4_BG_INODE_UNINIT) { 998 put_ext4(((uint64_t) 999 ((uint64_t)bgd[i].inode_id * 1000 (uint64_t)fs->blksz)), 1001 zero_buffer, fs->blksz); 1002 bgd[i].bg_flags = bgd[i].bg_flags & 1003 ~EXT4_BG_INODE_UNINIT; 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 bgd[i].free_inodes--; 1016 bgd[i].bg_itable_unused--; 1017 fs->sb->free_inodes--; 1018 status = ext4fs_devread((lbaint_t) 1019 bgd[i].inode_id * 1020 fs->sect_perblk, 0, 1021 fs->blksz, 1022 journal_buffer); 1023 if (status == 0) 1024 goto fail; 1025 if (ext4fs_log_journal(journal_buffer, 1026 bgd[i].inode_id)) 1027 goto fail; 1028 goto success; 1029 } else 1030 debug("no inode left on block group %d\n", i); 1031 } 1032 goto fail; 1033 } else { 1034 restart: 1035 fs->curr_inode_no++; 1036 /* get the blockbitmap index respective to blockno */ 1037 ibmap_idx = fs->curr_inode_no / inodes_per_grp; 1038 if (bgd[ibmap_idx].bg_flags & EXT4_BG_INODE_UNINIT) { 1039 memset(zero_buffer, '\0', fs->blksz); 1040 put_ext4(((uint64_t) ((uint64_t)bgd[ibmap_idx].inode_id * 1041 (uint64_t)fs->blksz)), zero_buffer, 1042 fs->blksz); 1043 bgd[ibmap_idx].bg_flags = 1044 bgd[ibmap_idx].bg_flags & ~EXT4_BG_INODE_UNINIT; 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((lbaint_t) 1061 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 bgd[ibmap_idx].inode_id)) 1068 goto fail; 1069 prev_inode_bitmap_index = ibmap_idx; 1070 } 1071 if (bgd[ibmap_idx].bg_itable_unused != 1072 bgd[ibmap_idx].free_inodes) 1073 bgd[ibmap_idx].bg_itable_unused = 1074 bgd[ibmap_idx].free_inodes; 1075 bgd[ibmap_idx].free_inodes--; 1076 bgd[ibmap_idx].bg_itable_unused--; 1077 fs->sb->free_inodes--; 1078 goto success; 1079 } 1080 1081 success: 1082 free(journal_buffer); 1083 free(zero_buffer); 1084 1085 return fs->curr_inode_no; 1086 fail: 1087 free(journal_buffer); 1088 free(zero_buffer); 1089 1090 return -1; 1091 1092 } 1093 1094 1095 static void alloc_single_indirect_block(struct ext2_inode *file_inode, 1096 unsigned int *total_remaining_blocks, 1097 unsigned int *no_blks_reqd) 1098 { 1099 short i; 1100 short status; 1101 long int actual_block_no; 1102 long int si_blockno; 1103 /* si :single indirect */ 1104 unsigned int *si_buffer = NULL; 1105 unsigned int *si_start_addr = NULL; 1106 struct ext_filesystem *fs = get_fs(); 1107 1108 if (*total_remaining_blocks != 0) { 1109 si_buffer = zalloc(fs->blksz); 1110 if (!si_buffer) { 1111 printf("No Memory\n"); 1112 return; 1113 } 1114 si_start_addr = si_buffer; 1115 si_blockno = ext4fs_get_new_blk_no(); 1116 if (si_blockno == -1) { 1117 printf("no block left to assign\n"); 1118 goto fail; 1119 } 1120 (*no_blks_reqd)++; 1121 debug("SIPB %ld: %u\n", si_blockno, *total_remaining_blocks); 1122 1123 status = ext4fs_devread((lbaint_t)si_blockno * fs->sect_perblk, 1124 0, fs->blksz, (char *)si_buffer); 1125 memset(si_buffer, '\0', fs->blksz); 1126 if (status == 0) 1127 goto fail; 1128 1129 for (i = 0; i < (fs->blksz / sizeof(int)); i++) { 1130 actual_block_no = ext4fs_get_new_blk_no(); 1131 if (actual_block_no == -1) { 1132 printf("no block left to assign\n"); 1133 goto fail; 1134 } 1135 *si_buffer = actual_block_no; 1136 debug("SIAB %u: %u\n", *si_buffer, 1137 *total_remaining_blocks); 1138 1139 si_buffer++; 1140 (*total_remaining_blocks)--; 1141 if (*total_remaining_blocks == 0) 1142 break; 1143 } 1144 1145 /* write the block to disk */ 1146 put_ext4(((uint64_t) ((uint64_t)si_blockno * (uint64_t)fs->blksz)), 1147 si_start_addr, fs->blksz); 1148 file_inode->b.blocks.indir_block = si_blockno; 1149 } 1150 fail: 1151 free(si_start_addr); 1152 } 1153 1154 static void alloc_double_indirect_block(struct ext2_inode *file_inode, 1155 unsigned int *total_remaining_blocks, 1156 unsigned int *no_blks_reqd) 1157 { 1158 short i; 1159 short j; 1160 short status; 1161 long int actual_block_no; 1162 /* di:double indirect */ 1163 long int di_blockno_parent; 1164 long int di_blockno_child; 1165 unsigned int *di_parent_buffer = NULL; 1166 unsigned int *di_child_buff = NULL; 1167 unsigned int *di_block_start_addr = NULL; 1168 unsigned int *di_child_buff_start = NULL; 1169 struct ext_filesystem *fs = get_fs(); 1170 1171 if (*total_remaining_blocks != 0) { 1172 /* double indirect parent block connecting to inode */ 1173 di_blockno_parent = ext4fs_get_new_blk_no(); 1174 if (di_blockno_parent == -1) { 1175 printf("no block left to assign\n"); 1176 goto fail; 1177 } 1178 di_parent_buffer = zalloc(fs->blksz); 1179 if (!di_parent_buffer) 1180 goto fail; 1181 1182 di_block_start_addr = di_parent_buffer; 1183 (*no_blks_reqd)++; 1184 debug("DIPB %ld: %u\n", di_blockno_parent, 1185 *total_remaining_blocks); 1186 1187 status = ext4fs_devread((lbaint_t)di_blockno_parent * 1188 fs->sect_perblk, 0, 1189 fs->blksz, (char *)di_parent_buffer); 1190 1191 if (!status) { 1192 printf("%s: Device read error!\n", __func__); 1193 goto fail; 1194 } 1195 memset(di_parent_buffer, '\0', fs->blksz); 1196 1197 /* 1198 * start:for each double indirect parent 1199 * block create one more block 1200 */ 1201 for (i = 0; i < (fs->blksz / sizeof(int)); i++) { 1202 di_blockno_child = ext4fs_get_new_blk_no(); 1203 if (di_blockno_child == -1) { 1204 printf("no block left to assign\n"); 1205 goto fail; 1206 } 1207 di_child_buff = zalloc(fs->blksz); 1208 if (!di_child_buff) 1209 goto fail; 1210 1211 di_child_buff_start = di_child_buff; 1212 *di_parent_buffer = di_blockno_child; 1213 di_parent_buffer++; 1214 (*no_blks_reqd)++; 1215 debug("DICB %ld: %u\n", di_blockno_child, 1216 *total_remaining_blocks); 1217 1218 status = ext4fs_devread((lbaint_t)di_blockno_child * 1219 fs->sect_perblk, 0, 1220 fs->blksz, 1221 (char *)di_child_buff); 1222 1223 if (!status) { 1224 printf("%s: Device read error!\n", __func__); 1225 goto fail; 1226 } 1227 memset(di_child_buff, '\0', fs->blksz); 1228 /* filling of actual datablocks for each child */ 1229 for (j = 0; j < (fs->blksz / sizeof(int)); j++) { 1230 actual_block_no = ext4fs_get_new_blk_no(); 1231 if (actual_block_no == -1) { 1232 printf("no block left to assign\n"); 1233 goto fail; 1234 } 1235 *di_child_buff = actual_block_no; 1236 debug("DIAB %ld: %u\n", actual_block_no, 1237 *total_remaining_blocks); 1238 1239 di_child_buff++; 1240 (*total_remaining_blocks)--; 1241 if (*total_remaining_blocks == 0) 1242 break; 1243 } 1244 /* write the block table */ 1245 put_ext4(((uint64_t) ((uint64_t)di_blockno_child * (uint64_t)fs->blksz)), 1246 di_child_buff_start, fs->blksz); 1247 free(di_child_buff_start); 1248 di_child_buff_start = NULL; 1249 1250 if (*total_remaining_blocks == 0) 1251 break; 1252 } 1253 put_ext4(((uint64_t) ((uint64_t)di_blockno_parent * (uint64_t)fs->blksz)), 1254 di_block_start_addr, fs->blksz); 1255 file_inode->b.blocks.double_indir_block = di_blockno_parent; 1256 } 1257 fail: 1258 free(di_block_start_addr); 1259 } 1260 1261 static void alloc_triple_indirect_block(struct ext2_inode *file_inode, 1262 unsigned int *total_remaining_blocks, 1263 unsigned int *no_blks_reqd) 1264 { 1265 short i; 1266 short j; 1267 short k; 1268 long int actual_block_no; 1269 /* ti: Triple Indirect */ 1270 long int ti_gp_blockno; 1271 long int ti_parent_blockno; 1272 long int ti_child_blockno; 1273 unsigned int *ti_gp_buff = NULL; 1274 unsigned int *ti_parent_buff = NULL; 1275 unsigned int *ti_child_buff = NULL; 1276 unsigned int *ti_gp_buff_start_addr = NULL; 1277 unsigned int *ti_pbuff_start_addr = NULL; 1278 unsigned int *ti_cbuff_start_addr = NULL; 1279 struct ext_filesystem *fs = get_fs(); 1280 if (*total_remaining_blocks != 0) { 1281 /* triple indirect grand parent block connecting to inode */ 1282 ti_gp_blockno = ext4fs_get_new_blk_no(); 1283 if (ti_gp_blockno == -1) { 1284 printf("no block left to assign\n"); 1285 goto fail; 1286 } 1287 ti_gp_buff = zalloc(fs->blksz); 1288 if (!ti_gp_buff) 1289 goto fail; 1290 1291 ti_gp_buff_start_addr = ti_gp_buff; 1292 (*no_blks_reqd)++; 1293 debug("TIGPB %ld: %u\n", ti_gp_blockno, 1294 *total_remaining_blocks); 1295 1296 /* for each 4 byte grand parent entry create one more block */ 1297 for (i = 0; i < (fs->blksz / sizeof(int)); i++) { 1298 ti_parent_blockno = ext4fs_get_new_blk_no(); 1299 if (ti_parent_blockno == -1) { 1300 printf("no block left to assign\n"); 1301 goto fail; 1302 } 1303 ti_parent_buff = zalloc(fs->blksz); 1304 if (!ti_parent_buff) 1305 goto fail; 1306 1307 ti_pbuff_start_addr = ti_parent_buff; 1308 *ti_gp_buff = ti_parent_blockno; 1309 ti_gp_buff++; 1310 (*no_blks_reqd)++; 1311 debug("TIPB %ld: %u\n", ti_parent_blockno, 1312 *total_remaining_blocks); 1313 1314 /* for each 4 byte entry parent create one more block */ 1315 for (j = 0; j < (fs->blksz / sizeof(int)); j++) { 1316 ti_child_blockno = ext4fs_get_new_blk_no(); 1317 if (ti_child_blockno == -1) { 1318 printf("no block left assign\n"); 1319 goto fail; 1320 } 1321 ti_child_buff = zalloc(fs->blksz); 1322 if (!ti_child_buff) 1323 goto fail; 1324 1325 ti_cbuff_start_addr = ti_child_buff; 1326 *ti_parent_buff = ti_child_blockno; 1327 ti_parent_buff++; 1328 (*no_blks_reqd)++; 1329 debug("TICB %ld: %u\n", ti_parent_blockno, 1330 *total_remaining_blocks); 1331 1332 /* fill actual datablocks for each child */ 1333 for (k = 0; k < (fs->blksz / sizeof(int)); 1334 k++) { 1335 actual_block_no = 1336 ext4fs_get_new_blk_no(); 1337 if (actual_block_no == -1) { 1338 printf("no block left\n"); 1339 goto fail; 1340 } 1341 *ti_child_buff = actual_block_no; 1342 debug("TIAB %ld: %u\n", actual_block_no, 1343 *total_remaining_blocks); 1344 1345 ti_child_buff++; 1346 (*total_remaining_blocks)--; 1347 if (*total_remaining_blocks == 0) 1348 break; 1349 } 1350 /* write the child block */ 1351 put_ext4(((uint64_t) ((uint64_t)ti_child_blockno * 1352 (uint64_t)fs->blksz)), 1353 ti_cbuff_start_addr, fs->blksz); 1354 free(ti_cbuff_start_addr); 1355 1356 if (*total_remaining_blocks == 0) 1357 break; 1358 } 1359 /* write the parent block */ 1360 put_ext4(((uint64_t) ((uint64_t)ti_parent_blockno * (uint64_t)fs->blksz)), 1361 ti_pbuff_start_addr, fs->blksz); 1362 free(ti_pbuff_start_addr); 1363 1364 if (*total_remaining_blocks == 0) 1365 break; 1366 } 1367 /* write the grand parent block */ 1368 put_ext4(((uint64_t) ((uint64_t)ti_gp_blockno * (uint64_t)fs->blksz)), 1369 ti_gp_buff_start_addr, fs->blksz); 1370 file_inode->b.blocks.triple_indir_block = ti_gp_blockno; 1371 } 1372 fail: 1373 free(ti_gp_buff_start_addr); 1374 } 1375 1376 void ext4fs_allocate_blocks(struct ext2_inode *file_inode, 1377 unsigned int total_remaining_blocks, 1378 unsigned int *total_no_of_block) 1379 { 1380 short i; 1381 long int direct_blockno; 1382 unsigned int no_blks_reqd = 0; 1383 1384 /* allocation of direct blocks */ 1385 for (i = 0; total_remaining_blocks && i < INDIRECT_BLOCKS; i++) { 1386 direct_blockno = ext4fs_get_new_blk_no(); 1387 if (direct_blockno == -1) { 1388 printf("no block left to assign\n"); 1389 return; 1390 } 1391 file_inode->b.blocks.dir_blocks[i] = direct_blockno; 1392 debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks); 1393 1394 total_remaining_blocks--; 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 loff_t actread; 1897 struct ext2fs_node *diro = (struct ext2fs_node *) dir; 1898 1899 #ifdef DEBUG 1900 if (name != NULL) 1901 printf("Iterate dir %s\n", name); 1902 #endif /* of DEBUG */ 1903 if (!diro->inode_read) { 1904 status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode); 1905 if (status == 0) 1906 return 0; 1907 } 1908 /* Search the file. */ 1909 while (fpos < __le32_to_cpu(diro->inode.size)) { 1910 struct ext2_dirent dirent; 1911 1912 status = ext4fs_read_file(diro, fpos, 1913 sizeof(struct ext2_dirent), 1914 (char *)&dirent, &actread); 1915 if (status < 0) 1916 return 0; 1917 1918 if (dirent.namelen != 0) { 1919 char filename[dirent.namelen + 1]; 1920 struct ext2fs_node *fdiro; 1921 int type = FILETYPE_UNKNOWN; 1922 1923 status = ext4fs_read_file(diro, 1924 fpos + 1925 sizeof(struct ext2_dirent), 1926 dirent.namelen, filename, 1927 &actread); 1928 if (status < 0) 1929 return 0; 1930 1931 fdiro = zalloc(sizeof(struct ext2fs_node)); 1932 if (!fdiro) 1933 return 0; 1934 1935 fdiro->data = diro->data; 1936 fdiro->ino = __le32_to_cpu(dirent.inode); 1937 1938 filename[dirent.namelen] = '\0'; 1939 1940 if (dirent.filetype != FILETYPE_UNKNOWN) { 1941 fdiro->inode_read = 0; 1942 1943 if (dirent.filetype == FILETYPE_DIRECTORY) 1944 type = FILETYPE_DIRECTORY; 1945 else if (dirent.filetype == FILETYPE_SYMLINK) 1946 type = FILETYPE_SYMLINK; 1947 else if (dirent.filetype == FILETYPE_REG) 1948 type = FILETYPE_REG; 1949 } else { 1950 status = ext4fs_read_inode(diro->data, 1951 __le32_to_cpu 1952 (dirent.inode), 1953 &fdiro->inode); 1954 if (status == 0) { 1955 free(fdiro); 1956 return 0; 1957 } 1958 fdiro->inode_read = 1; 1959 1960 if ((__le16_to_cpu(fdiro->inode.mode) & 1961 FILETYPE_INO_MASK) == 1962 FILETYPE_INO_DIRECTORY) { 1963 type = FILETYPE_DIRECTORY; 1964 } else if ((__le16_to_cpu(fdiro->inode.mode) 1965 & FILETYPE_INO_MASK) == 1966 FILETYPE_INO_SYMLINK) { 1967 type = FILETYPE_SYMLINK; 1968 } else if ((__le16_to_cpu(fdiro->inode.mode) 1969 & FILETYPE_INO_MASK) == 1970 FILETYPE_INO_REG) { 1971 type = FILETYPE_REG; 1972 } 1973 } 1974 #ifdef DEBUG 1975 printf("iterate >%s<\n", filename); 1976 #endif /* of DEBUG */ 1977 if ((name != NULL) && (fnode != NULL) 1978 && (ftype != NULL)) { 1979 if (strcmp(filename, name) == 0) { 1980 *ftype = type; 1981 *fnode = fdiro; 1982 return 1; 1983 } 1984 } else { 1985 if (fdiro->inode_read == 0) { 1986 status = ext4fs_read_inode(diro->data, 1987 __le32_to_cpu( 1988 dirent.inode), 1989 &fdiro->inode); 1990 if (status == 0) { 1991 free(fdiro); 1992 return 0; 1993 } 1994 fdiro->inode_read = 1; 1995 } 1996 switch (type) { 1997 case FILETYPE_DIRECTORY: 1998 printf("<DIR> "); 1999 break; 2000 case FILETYPE_SYMLINK: 2001 printf("<SYM> "); 2002 break; 2003 case FILETYPE_REG: 2004 printf(" "); 2005 break; 2006 default: 2007 printf("< ? > "); 2008 break; 2009 } 2010 printf("%10u %s\n", 2011 __le32_to_cpu(fdiro->inode.size), 2012 filename); 2013 } 2014 free(fdiro); 2015 } 2016 fpos += __le16_to_cpu(dirent.direntlen); 2017 } 2018 return 0; 2019 } 2020 2021 static char *ext4fs_read_symlink(struct ext2fs_node *node) 2022 { 2023 char *symlink; 2024 struct ext2fs_node *diro = node; 2025 int status; 2026 loff_t actread; 2027 2028 if (!diro->inode_read) { 2029 status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode); 2030 if (status == 0) 2031 return 0; 2032 } 2033 symlink = zalloc(__le32_to_cpu(diro->inode.size) + 1); 2034 if (!symlink) 2035 return 0; 2036 2037 if (__le32_to_cpu(diro->inode.size) <= 60) { 2038 strncpy(symlink, diro->inode.b.symlink, 2039 __le32_to_cpu(diro->inode.size)); 2040 } else { 2041 status = ext4fs_read_file(diro, 0, 2042 __le32_to_cpu(diro->inode.size), 2043 symlink, &actread); 2044 if (status == 0) { 2045 free(symlink); 2046 return 0; 2047 } 2048 } 2049 symlink[__le32_to_cpu(diro->inode.size)] = '\0'; 2050 return symlink; 2051 } 2052 2053 static int ext4fs_find_file1(const char *currpath, 2054 struct ext2fs_node *currroot, 2055 struct ext2fs_node **currfound, int *foundtype) 2056 { 2057 char fpath[strlen(currpath) + 1]; 2058 char *name = fpath; 2059 char *next; 2060 int status; 2061 int type = FILETYPE_DIRECTORY; 2062 struct ext2fs_node *currnode = currroot; 2063 struct ext2fs_node *oldnode = currroot; 2064 2065 strncpy(fpath, currpath, strlen(currpath) + 1); 2066 2067 /* Remove all leading slashes. */ 2068 while (*name == '/') 2069 name++; 2070 2071 if (!*name) { 2072 *currfound = currnode; 2073 return 1; 2074 } 2075 2076 for (;;) { 2077 int found; 2078 2079 /* Extract the actual part from the pathname. */ 2080 next = strchr(name, '/'); 2081 if (next) { 2082 /* Remove all leading slashes. */ 2083 while (*next == '/') 2084 *(next++) = '\0'; 2085 } 2086 2087 if (type != FILETYPE_DIRECTORY) { 2088 ext4fs_free_node(currnode, currroot); 2089 return 0; 2090 } 2091 2092 oldnode = currnode; 2093 2094 /* Iterate over the directory. */ 2095 found = ext4fs_iterate_dir(currnode, name, &currnode, &type); 2096 if (found == 0) 2097 return 0; 2098 2099 if (found == -1) 2100 break; 2101 2102 /* Read in the symlink and follow it. */ 2103 if (type == FILETYPE_SYMLINK) { 2104 char *symlink; 2105 2106 /* Test if the symlink does not loop. */ 2107 if (++symlinknest == 8) { 2108 ext4fs_free_node(currnode, currroot); 2109 ext4fs_free_node(oldnode, currroot); 2110 return 0; 2111 } 2112 2113 symlink = ext4fs_read_symlink(currnode); 2114 ext4fs_free_node(currnode, currroot); 2115 2116 if (!symlink) { 2117 ext4fs_free_node(oldnode, currroot); 2118 return 0; 2119 } 2120 2121 debug("Got symlink >%s<\n", symlink); 2122 2123 if (symlink[0] == '/') { 2124 ext4fs_free_node(oldnode, currroot); 2125 oldnode = &ext4fs_root->diropen; 2126 } 2127 2128 /* Lookup the node the symlink points to. */ 2129 status = ext4fs_find_file1(symlink, oldnode, 2130 &currnode, &type); 2131 2132 free(symlink); 2133 2134 if (status == 0) { 2135 ext4fs_free_node(oldnode, currroot); 2136 return 0; 2137 } 2138 } 2139 2140 ext4fs_free_node(oldnode, currroot); 2141 2142 /* Found the node! */ 2143 if (!next || *next == '\0') { 2144 *currfound = currnode; 2145 *foundtype = type; 2146 return 1; 2147 } 2148 name = next; 2149 } 2150 return -1; 2151 } 2152 2153 int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode, 2154 struct ext2fs_node **foundnode, int expecttype) 2155 { 2156 int status; 2157 int foundtype = FILETYPE_DIRECTORY; 2158 2159 symlinknest = 0; 2160 if (!path) 2161 return 0; 2162 2163 status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype); 2164 if (status == 0) 2165 return 0; 2166 2167 /* Check if the node that was found was of the expected type. */ 2168 if ((expecttype == FILETYPE_REG) && (foundtype != expecttype)) 2169 return 0; 2170 else if ((expecttype == FILETYPE_DIRECTORY) 2171 && (foundtype != expecttype)) 2172 return 0; 2173 2174 return 1; 2175 } 2176 2177 int ext4fs_open(const char *filename, loff_t *len) 2178 { 2179 struct ext2fs_node *fdiro = NULL; 2180 int status; 2181 2182 if (ext4fs_root == NULL) 2183 return -1; 2184 2185 ext4fs_file = NULL; 2186 status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro, 2187 FILETYPE_REG); 2188 if (status == 0) 2189 goto fail; 2190 2191 if (!fdiro->inode_read) { 2192 status = ext4fs_read_inode(fdiro->data, fdiro->ino, 2193 &fdiro->inode); 2194 if (status == 0) 2195 goto fail; 2196 } 2197 *len = __le32_to_cpu(fdiro->inode.size); 2198 ext4fs_file = fdiro; 2199 2200 return 0; 2201 fail: 2202 ext4fs_free_node(fdiro, &ext4fs_root->diropen); 2203 2204 return -1; 2205 } 2206 2207 int ext4fs_mount(unsigned part_length) 2208 { 2209 struct ext2_data *data; 2210 int status; 2211 struct ext_filesystem *fs = get_fs(); 2212 data = zalloc(SUPERBLOCK_SIZE); 2213 if (!data) 2214 return 0; 2215 2216 /* Read the superblock. */ 2217 status = ext4_read_superblock((char *)&data->sblock); 2218 2219 if (status == 0) 2220 goto fail; 2221 2222 /* Make sure this is an ext2 filesystem. */ 2223 if (__le16_to_cpu(data->sblock.magic) != EXT2_MAGIC) 2224 goto fail; 2225 2226 if (__le32_to_cpu(data->sblock.revision_level == 0)) 2227 fs->inodesz = 128; 2228 else 2229 fs->inodesz = __le16_to_cpu(data->sblock.inode_size); 2230 2231 debug("EXT2 rev %d, inode_size %d\n", 2232 __le32_to_cpu(data->sblock.revision_level), fs->inodesz); 2233 2234 data->diropen.data = data; 2235 data->diropen.ino = 2; 2236 data->diropen.inode_read = 1; 2237 data->inode = &data->diropen.inode; 2238 2239 status = ext4fs_read_inode(data, 2, data->inode); 2240 if (status == 0) 2241 goto fail; 2242 2243 ext4fs_root = data; 2244 2245 return 1; 2246 fail: 2247 printf("Failed to mount ext2 filesystem...\n"); 2248 free(data); 2249 ext4fs_root = NULL; 2250 2251 return 0; 2252 } 2253