e2image.c revision d0ff90d5202428583c78a60c3042e7b60d88bc45
1/* 2 * e2image.c --- Program which writes an image file backing up 3 * critical metadata for the filesystem. 4 * 5 * Copyright 2000, 2001 by Theodore Ts'o. 6 * 7 * %Begin-Header% 8 * This file may be redistributed under the terms of the GNU Public 9 * License. 10 * %End-Header% 11 */ 12 13#define _LARGEFILE_SOURCE 14#define _LARGEFILE64_SOURCE 15 16#include <fcntl.h> 17#include <grp.h> 18#ifdef HAVE_GETOPT_H 19#include <getopt.h> 20#else 21extern char *optarg; 22extern int optind; 23#endif 24#include <pwd.h> 25#include <stdio.h> 26#include <stdlib.h> 27#include <string.h> 28#include <time.h> 29#include <unistd.h> 30#include <fcntl.h> 31#include <errno.h> 32#include <sys/stat.h> 33#include <sys/types.h> 34 35#include "ext2fs/ext2_fs.h" 36#include "ext2fs/ext2fs.h" 37#include "et/com_err.h" 38#include "uuid/uuid.h" 39#include "e2p/e2p.h" 40#include "ext2fs/e2image.h" 41 42#include "../version.h" 43#include "nls-enable.h" 44 45const char * program_name = "e2image"; 46char * device_name = NULL; 47 48static void usage(void) 49{ 50 fprintf(stderr, _("Usage: %s [-rsI] device image_file\n"), 51 program_name); 52 exit (1); 53} 54 55static void write_header(int fd, struct ext2_image_hdr *hdr, int blocksize) 56{ 57 char *header_buf; 58 int actual; 59 60 header_buf = malloc(blocksize); 61 if (!header_buf) { 62 fputs(_("Couldn't allocate header buffer\n"), stderr); 63 exit(1); 64 } 65 66 if (lseek(fd, 0, SEEK_SET) < 0) { 67 perror("lseek while writing header"); 68 exit(1); 69 } 70 memset(header_buf, 0, blocksize); 71 72 if (hdr) 73 memcpy(header_buf, hdr, sizeof(struct ext2_image_hdr)); 74 75 actual = write(fd, header_buf, blocksize); 76 if (actual < 0) { 77 perror("write header"); 78 exit(1); 79 } 80 if (actual != blocksize) { 81 fprintf(stderr, _("short write (only %d bytes) for " 82 "writing image header"), actual); 83 exit(1); 84 } 85 free(header_buf); 86} 87 88static void write_image_file(ext2_filsys fs, int fd) 89{ 90 struct ext2_image_hdr hdr; 91 struct stat st; 92 errcode_t retval; 93 94 write_header(fd, NULL, fs->blocksize); 95 memset(&hdr, 0, sizeof(struct ext2_image_hdr)); 96 97 hdr.offset_super = lseek(fd, 0, SEEK_CUR); 98 retval = ext2fs_image_super_write(fs, fd, 0); 99 if (retval) { 100 com_err(program_name, retval, _("while writing superblock")); 101 exit(1); 102 } 103 104 hdr.offset_inode = lseek(fd, 0, SEEK_CUR); 105 retval = ext2fs_image_inode_write(fs, fd, 106 (fd != 1) ? IMAGER_FLAG_SPARSEWRITE : 0); 107 if (retval) { 108 com_err(program_name, retval, _("while writing inode table")); 109 exit(1); 110 } 111 112 hdr.offset_blockmap = lseek(fd, 0, SEEK_CUR); 113 retval = ext2fs_image_bitmap_write(fs, fd, 0); 114 if (retval) { 115 com_err(program_name, retval, _("while writing block bitmap")); 116 exit(1); 117 } 118 119 hdr.offset_inodemap = lseek(fd, 0, SEEK_CUR); 120 retval = ext2fs_image_bitmap_write(fs, fd, IMAGER_FLAG_INODEMAP); 121 if (retval) { 122 com_err(program_name, retval, _("while writing inode bitmap")); 123 exit(1); 124 } 125 126 hdr.magic_number = EXT2_ET_MAGIC_E2IMAGE; 127 strcpy(hdr.magic_descriptor, "Ext2 Image 1.0"); 128 gethostname(hdr.fs_hostname, sizeof(hdr.fs_hostname)); 129 strncat(hdr.fs_device_name, device_name, sizeof(hdr.fs_device_name)); 130 hdr.fs_device_name[sizeof(hdr.fs_device_name) - 1] = 0; 131 hdr.fs_blocksize = fs->blocksize; 132 133 if (stat(device_name, &st) == 0) 134 hdr.fs_device = st.st_rdev; 135 136 if (fstat(fd, &st) == 0) { 137 hdr.image_device = st.st_dev; 138 hdr.image_inode = st.st_ino; 139 } 140 memcpy(hdr.fs_uuid, fs->super->s_uuid, sizeof(hdr.fs_uuid)); 141 142 hdr.image_time = time(0); 143 write_header(fd, &hdr, fs->blocksize); 144} 145 146/* 147 * These set of functions are used to write a RAW image file. 148 */ 149ext2fs_block_bitmap meta_block_map; 150ext2fs_block_bitmap scramble_block_map; /* Directory blocks to be scrambled */ 151 152struct process_block_struct { 153 ext2_ino_t ino; 154 int is_dir; 155}; 156 157/* 158 * These subroutines short circuits ext2fs_get_blocks and 159 * ext2fs_check_directory; we use them since we already have the inode 160 * structure, so there's no point in letting the ext2fs library read 161 * the inode again. 162 */ 163static ino_t stashed_ino = 0; 164static struct ext2_inode *stashed_inode; 165 166static errcode_t meta_get_blocks(ext2_filsys fs EXT2FS_ATTR((unused)), 167 ext2_ino_t ino, 168 blk_t *blocks) 169{ 170 int i; 171 172 if ((ino != stashed_ino) || !stashed_inode) 173 return EXT2_ET_CALLBACK_NOTHANDLED; 174 175 for (i=0; i < EXT2_N_BLOCKS; i++) 176 blocks[i] = stashed_inode->i_block[i]; 177 return 0; 178} 179 180static errcode_t meta_check_directory(ext2_filsys fs EXT2FS_ATTR((unused)), 181 ext2_ino_t ino) 182{ 183 if ((ino != stashed_ino) || !stashed_inode) 184 return EXT2_ET_CALLBACK_NOTHANDLED; 185 186 if (!LINUX_S_ISDIR(stashed_inode->i_mode)) 187 return EXT2_ET_NO_DIRECTORY; 188 return 0; 189} 190 191static errcode_t meta_read_inode(ext2_filsys fs EXT2FS_ATTR((unused)), 192 ext2_ino_t ino, 193 struct ext2_inode *inode) 194{ 195 if ((ino != stashed_ino) || !stashed_inode) 196 return EXT2_ET_CALLBACK_NOTHANDLED; 197 *inode = *stashed_inode; 198 return 0; 199} 200 201static void use_inode_shortcuts(ext2_filsys fs, int bool) 202{ 203 if (bool) { 204 fs->get_blocks = meta_get_blocks; 205 fs->check_directory = meta_check_directory; 206 fs->read_inode = meta_read_inode; 207 stashed_ino = 0; 208 } else { 209 fs->get_blocks = 0; 210 fs->check_directory = 0; 211 fs->read_inode = 0; 212 } 213} 214 215static int process_dir_block(ext2_filsys fs EXT2FS_ATTR((unused)), 216 blk_t *block_nr, 217 e2_blkcnt_t blockcnt EXT2FS_ATTR((unused)), 218 blk_t ref_block EXT2FS_ATTR((unused)), 219 int ref_offset EXT2FS_ATTR((unused)), 220 void *priv_data EXT2FS_ATTR((unused))) 221{ 222 struct process_block_struct *p; 223 224 p = (struct process_block_struct *) priv_data; 225 226 ext2fs_mark_block_bitmap(meta_block_map, *block_nr); 227 if (scramble_block_map && p->is_dir && blockcnt >= 0) 228 ext2fs_mark_block_bitmap(scramble_block_map, *block_nr); 229 return 0; 230} 231 232static int process_file_block(ext2_filsys fs EXT2FS_ATTR((unused)), 233 blk_t *block_nr, 234 e2_blkcnt_t blockcnt, 235 blk_t ref_block EXT2FS_ATTR((unused)), 236 int ref_offset EXT2FS_ATTR((unused)), 237 void *priv_data EXT2FS_ATTR((unused))) 238{ 239 if (blockcnt < 0) { 240 ext2fs_mark_block_bitmap(meta_block_map, *block_nr); 241 } 242 return 0; 243} 244 245static void mark_table_blocks(ext2_filsys fs) 246{ 247 blk_t first_block, b; 248 unsigned int i,j; 249 250 first_block = fs->super->s_first_data_block; 251 /* 252 * Mark primary superblock 253 */ 254 ext2fs_mark_block_bitmap(meta_block_map, first_block); 255 256 /* 257 * Mark the primary superblock descriptors 258 */ 259 for (j = 0; j < fs->desc_blocks; j++) { 260 ext2fs_mark_block_bitmap(meta_block_map, 261 ext2fs_descriptor_block_loc(fs, first_block, j)); 262 } 263 264 for (i = 0; i < fs->group_desc_count; i++) { 265 /* 266 * Mark the blocks used for the inode table 267 */ 268 if (fs->group_desc[i].bg_inode_table) { 269 for (j = 0, b = fs->group_desc[i].bg_inode_table; 270 j < (unsigned) fs->inode_blocks_per_group; 271 j++, b++) 272 ext2fs_mark_block_bitmap(meta_block_map, b); 273 } 274 275 /* 276 * Mark block used for the block bitmap 277 */ 278 if (fs->group_desc[i].bg_block_bitmap) { 279 ext2fs_mark_block_bitmap(meta_block_map, 280 fs->group_desc[i].bg_block_bitmap); 281 } 282 283 /* 284 * Mark block used for the inode bitmap 285 */ 286 if (fs->group_desc[i].bg_inode_bitmap) { 287 ext2fs_mark_block_bitmap(meta_block_map, 288 fs->group_desc[i].bg_inode_bitmap); 289 } 290 } 291} 292 293/* 294 * This function returns 1 if the specified block is all zeros 295 */ 296static int check_zero_block(char *buf, int blocksize) 297{ 298 char *cp = buf; 299 int left = blocksize; 300 301 while (left > 0) { 302 if (*cp++) 303 return 0; 304 left--; 305 } 306 return 1; 307} 308 309static void write_block(int fd, char *buf, int sparse_offset, 310 int blocksize, blk_t block) 311{ 312 int count; 313 errcode_t err; 314 315 if (sparse_offset) { 316#ifdef HAVE_LSEEK64 317 if (lseek64(fd, sparse_offset, SEEK_CUR) < 0) 318 perror("lseek"); 319#else 320 if (lseek(fd, sparse_offset, SEEK_CUR) < 0) 321 perror("lseek"); 322#endif 323 } 324 if (blocksize) { 325 count = write(fd, buf, blocksize); 326 if (count != blocksize) { 327 if (count == -1) 328 err = errno; 329 else 330 err = 0; 331 com_err(program_name, err, "error writing block %u", 332 block); 333 } 334 } 335} 336 337int name_id[256]; 338 339static void scramble_dir_block(ext2_filsys fs, blk_t blk, char *buf) 340{ 341 char *p, *end, *cp; 342 struct ext2_dir_entry_2 *dirent; 343 int rec_len, id, len; 344 345 end = buf + fs->blocksize; 346 for (p = buf; p < end-8; p += rec_len) { 347 dirent = (struct ext2_dir_entry_2 *) p; 348 rec_len = dirent->rec_len; 349#ifdef EXT2FS_ENABLE_SWAPFS 350 if (fs->flags & EXT2_FLAG_SWAP_BYTES) 351 rec_len = ext2fs_swab16(rec_len); 352#endif 353#if 0 354 printf("rec_len = %d, name_len = %d\n", rec_len, dirent->name_len); 355#endif 356 if (rec_len < 8 || (rec_len % 4) || 357 (p+rec_len > end)) { 358 printf("Corrupt directory block %lu: " 359 "bad rec_len (%d)\n", (unsigned long) blk, 360 rec_len); 361 rec_len = end - p; 362#ifdef EXT2FS_ENABLE_SWAPFS 363 if (fs->flags & EXT2_FLAG_SWAP_BYTES) 364 dirent->rec_len = ext2fs_swab16(rec_len); 365#endif 366 continue; 367 } 368 if (dirent->name_len + 8 > rec_len) { 369 printf("Corrupt directory block %lu: " 370 "bad name_len (%d)\n", (unsigned long) blk, 371 dirent->name_len); 372 dirent->name_len = rec_len - 8; 373 continue; 374 } 375 cp = p+8; 376 len = rec_len - dirent->name_len - 8; 377 if (len > 0) 378 memset(cp+dirent->name_len, 0, len); 379 if (dirent->name_len==1 && cp[0] == '.') 380 continue; 381 if (dirent->name_len==2 && cp[0] == '.' && cp[1] == '.') 382 continue; 383 384 memset(cp, 'A', dirent->name_len); 385 len = dirent->name_len; 386 id = name_id[len]++; 387 while ((len > 0) && (id > 0)) { 388 *cp += id % 26; 389 id = id / 26; 390 cp++; 391 len--; 392 } 393 } 394} 395 396static void output_meta_data_blocks(ext2_filsys fs, int fd) 397{ 398 errcode_t retval; 399 blk_t blk; 400 char *buf, *zero_buf; 401 int sparse = 0; 402 403 buf = malloc(fs->blocksize); 404 if (!buf) { 405 com_err(program_name, ENOMEM, "while allocating buffer"); 406 exit(1); 407 } 408 zero_buf = malloc(fs->blocksize); 409 if (!zero_buf) { 410 com_err(program_name, ENOMEM, "while allocating buffer"); 411 exit(1); 412 } 413 memset(zero_buf, 0, fs->blocksize); 414 for (blk = 0; blk < fs->super->s_blocks_count; blk++) { 415 if ((blk >= fs->super->s_first_data_block) && 416 ext2fs_test_block_bitmap(meta_block_map, blk)) { 417 retval = io_channel_read_blk(fs->io, blk, 1, buf); 418 if (retval) { 419 com_err(program_name, retval, 420 "error reading block %u", blk); 421 } 422 if (scramble_block_map && 423 ext2fs_test_block_bitmap(scramble_block_map, blk)) 424 scramble_dir_block(fs, blk, buf); 425 if ((fd != 1) && check_zero_block(buf, fs->blocksize)) 426 goto sparse_write; 427 write_block(fd, buf, sparse, fs->blocksize, blk); 428 sparse = 0; 429 } else { 430 sparse_write: 431 if (fd == 1) { 432 write_block(fd, zero_buf, 0, 433 fs->blocksize, blk); 434 continue; 435 } 436 sparse += fs->blocksize; 437 if (sparse >= 1024*1024) { 438 write_block(fd, 0, sparse, 0, 0); 439 sparse = 0; 440 } 441 } 442 } 443 write_block(fd, zero_buf, sparse, 1, -1); 444} 445 446static void write_raw_image_file(ext2_filsys fs, int fd, int scramble_flag) 447{ 448 struct process_block_struct pb; 449 struct ext2_inode inode; 450 ext2_inode_scan scan; 451 ext2_ino_t ino; 452 errcode_t retval; 453 char * block_buf; 454 455 retval = ext2fs_allocate_block_bitmap(fs, "in-use block map", 456 &meta_block_map); 457 if (retval) { 458 com_err(program_name, retval, "while allocating block bitmap"); 459 exit(1); 460 } 461 462 if (scramble_flag) { 463 retval = ext2fs_allocate_block_bitmap(fs, "scramble block map", 464 &scramble_block_map); 465 if (retval) { 466 com_err(program_name, retval, 467 "while allocating scramble block bitmap"); 468 exit(1); 469 } 470 } 471 472 mark_table_blocks(fs); 473 474 retval = ext2fs_open_inode_scan(fs, 0, &scan); 475 if (retval) { 476 com_err(program_name, retval, _("while opening inode scan")); 477 exit(1); 478 } 479 480 block_buf = malloc(fs->blocksize * 3); 481 if (!block_buf) { 482 com_err(program_name, 0, "Can't allocate block buffer"); 483 exit(1); 484 } 485 486 use_inode_shortcuts(fs, 1); 487 stashed_inode = &inode; 488 while (1) { 489 retval = ext2fs_get_next_inode(scan, &ino, &inode); 490 if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE) 491 continue; 492 if (retval) { 493 com_err(program_name, retval, 494 _("while getting next inode")); 495 exit(1); 496 } 497 if (ino == 0) 498 break; 499 if (!inode.i_links_count) 500 continue; 501 if (inode.i_file_acl) { 502 ext2fs_mark_block_bitmap(meta_block_map, 503 inode.i_file_acl); 504 } 505 if (!ext2fs_inode_has_valid_blocks(&inode)) 506 continue; 507 508 stashed_ino = ino; 509 pb.ino = ino; 510 pb.is_dir = LINUX_S_ISDIR(inode.i_mode); 511 if (LINUX_S_ISDIR(inode.i_mode) || 512 (LINUX_S_ISLNK(inode.i_mode) && 513 ext2fs_inode_has_valid_blocks(&inode)) || 514 ino == fs->super->s_journal_inum) { 515 retval = ext2fs_block_iterate2(fs, ino, 0, 516 block_buf, process_dir_block, &pb); 517 if (retval) { 518 com_err(program_name, retval, 519 "while iterating over inode %u", 520 ino); 521 exit(1); 522 } 523 } else { 524 if (inode.i_block[EXT2_IND_BLOCK] || 525 inode.i_block[EXT2_DIND_BLOCK] || 526 inode.i_block[EXT2_TIND_BLOCK]) { 527 retval = ext2fs_block_iterate2(fs, 528 ino, 0, block_buf, 529 process_file_block, &pb); 530 if (retval) { 531 com_err(program_name, retval, 532 "while iterating over inode %u", ino); 533 exit(1); 534 } 535 } 536 } 537 } 538 use_inode_shortcuts(fs, 0); 539 output_meta_data_blocks(fs, fd); 540} 541 542static void install_image(char *device, char *image_fn, int raw_flag) 543{ 544 errcode_t retval; 545 ext2_filsys fs; 546 int open_flag = EXT2_FLAG_IMAGE_FILE; 547 int fd = 0; 548 io_manager io_ptr; 549 io_channel io, image_io; 550 551 if (raw_flag) { 552 com_err(program_name, 0, "Raw images cannot be installed"); 553 exit(1); 554 } 555 556#ifdef CONFIG_TESTIO_DEBUG 557 io_ptr = test_io_manager; 558 test_io_backing_manager = unix_io_manager; 559#else 560 io_ptr = unix_io_manager; 561#endif 562 563 retval = ext2fs_open (image_fn, open_flag, 0, 0, 564 io_ptr, &fs); 565 if (retval) { 566 com_err (program_name, retval, _("while trying to open %s"), 567 image_fn); 568 exit(1); 569 } 570 571 retval = ext2fs_read_bitmaps (fs); 572 if (retval) { 573 com_err(program_name, retval, "error reading bitmaps"); 574 exit(1); 575 } 576 577 578 fd = open(image_fn, O_RDONLY); 579 if (fd < 0) { 580 perror(image_fn); 581 exit(1); 582 } 583 584 retval = io_ptr->open(device, IO_FLAG_RW, &io); 585 if (retval) { 586 com_err(device, 0, "while opening device file"); 587 exit(1); 588 } 589 590 image_io = fs->io; 591 592 ext2fs_rewrite_to_io(fs, io); 593 594 if (lseek(fd, fs->image_header->offset_inode, SEEK_SET) < 0) { 595 perror("lseek"); 596 exit(1); 597 } 598 599 retval = ext2fs_image_inode_read(fs, fd, 0); 600 if (retval) { 601 com_err(image_fn, 0, "while restoring the image table"); 602 exit(1); 603 } 604 605 ext2fs_close (fs); 606 exit (0); 607} 608 609int main (int argc, char ** argv) 610{ 611 int c; 612 errcode_t retval; 613 ext2_filsys fs; 614 char *image_fn; 615 int open_flag = 0; 616 int raw_flag = 0; 617 int install_flag = 0; 618 int scramble_flag = 0; 619 int fd = 0; 620 621#ifdef ENABLE_NLS 622 setlocale(LC_MESSAGES, ""); 623 setlocale(LC_CTYPE, ""); 624 bindtextdomain(NLS_CAT_NAME, LOCALEDIR); 625 textdomain(NLS_CAT_NAME); 626#endif 627 fprintf (stderr, "e2image %s (%s)\n", E2FSPROGS_VERSION, 628 E2FSPROGS_DATE); 629 if (argc && *argv) 630 program_name = *argv; 631 initialize_ext2_error_table(); 632 while ((c = getopt (argc, argv, "rsI")) != EOF) 633 switch (c) { 634 case 'r': 635 raw_flag++; 636 break; 637 case 's': 638 scramble_flag++; 639 break; 640 case 'I': 641 install_flag++; 642 break; 643 default: 644 usage(); 645 } 646 if (optind != argc - 2 ) 647 usage(); 648 device_name = argv[optind]; 649 image_fn = argv[optind+1]; 650 651 if (install_flag) { 652 install_image(device_name, image_fn, raw_flag); 653 exit (0); 654 } 655 656 retval = ext2fs_open (device_name, open_flag, 0, 0, 657 unix_io_manager, &fs); 658 if (retval) { 659 com_err (program_name, retval, _("while trying to open %s"), 660 device_name); 661 fputs(_("Couldn't find valid filesystem superblock.\n"), stdout); 662 exit(1); 663 } 664 665 if (strcmp(image_fn, "-") == 0) 666 fd = 1; 667 else { 668#ifdef HAVE_OPEN64 669 fd = open64(image_fn, O_CREAT|O_TRUNC|O_WRONLY, 0600); 670#else 671 fd = open(image_fn, O_CREAT|O_TRUNC|O_WRONLY, 0600); 672#endif 673 if (fd < 0) { 674 com_err(program_name, errno, 675 _("while trying to open %s"), argv[optind+1]); 676 exit(1); 677 } 678 } 679 680 if (raw_flag) 681 write_raw_image_file(fs, fd, scramble_flag); 682 else 683 write_image_file(fs, fd); 684 685 ext2fs_close (fs); 686 exit (0); 687} 688