misc/e2image.c

   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
  21 extern char *optarg;
  22 extern 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
  45 const char * program_name = "e2image";
  46 char * device_name = NULL;
  47
  48 static void usage(void)
  49 {
  50         fprintf(stderr, _("Usage: %s [-r] device file\n"), program_name);
  51         exit (1);
  52 }
  53
  54 static void write_header(int fd, struct ext2_image_hdr *hdr, int blocksize)
  55 {
  56         char *header_buf;
  57         int actual;
  58
  59         header_buf = malloc(blocksize);
  60         if (!header_buf) {
  61                 fputs(_("Couldn't allocate header buffer\n"), stderr);
  62                 exit(1);
  63         }
  64
  65         if (lseek(fd, 0, SEEK_SET) < 0) {
  66                 perror("lseek while writing header");
  67                 exit(1);
  68         }
  69         memset(header_buf, 0, blocksize);
  70
  71         if (hdr)
  72                 memcpy(header_buf, hdr, sizeof(struct ext2_image_hdr));
  73
  74         actual = write(fd, header_buf, blocksize);
  75         if (actual < 0) {
  76                 perror("write header");
  77                 exit(1);
  78         }
  79         if (actual != blocksize) {
  80                 fprintf(stderr, _("short write (only %d bytes) for "
  81                                   "writing image header"), actual);
  82                 exit(1);
  83         }
  84         free(header_buf);
  85 }
  86
  87 static void write_image_file(ext2_filsys fs, int fd)
  88 {
  89         struct ext2_image_hdr   hdr;
  90         struct stat             st;
  91         errcode_t               retval;
  92
  93         write_header(fd, NULL, fs->blocksize);
  94         memset(&hdr, 0, sizeof(struct ext2_image_hdr));
  95
  96         hdr.offset_super = lseek(fd, 0, SEEK_CUR);
  97         retval = ext2fs_image_super_write(fs, fd, 0);
  98         if (retval) {
  99                 com_err(program_name, retval, _("while writing superblock"));
 100                 exit(1);
 101         }
 102
 103         hdr.offset_inode = lseek(fd, 0, SEEK_CUR);
 104         retval = ext2fs_image_inode_write(fs, fd,
 105                                   (fd != 1) ? IMAGER_FLAG_SPARSEWRITE : 0);
 106         if (retval) {
 107                 com_err(program_name, retval, _("while writing inode table"));
 108                 exit(1);
 109         }
 110
 111         hdr.offset_blockmap = lseek(fd, 0, SEEK_CUR);
 112         retval = ext2fs_image_bitmap_write(fs, fd, 0);
 113         if (retval) {
 114                 com_err(program_name, retval, _("while writing block bitmap"));
 115                 exit(1);
 116         }
 117
 118         hdr.offset_inodemap = lseek(fd, 0, SEEK_CUR);
 119         retval = ext2fs_image_bitmap_write(fs, fd, IMAGER_FLAG_INODEMAP);
 120         if (retval) {
 121                 com_err(program_name, retval, _("while writing inode bitmap"));
 122                 exit(1);
 123         }
 124
 125         hdr.magic_number = EXT2_ET_MAGIC_E2IMAGE;
 126         strcpy(hdr.magic_descriptor, "Ext2 Image 1.0");
 127         gethostname(hdr.fs_hostname, sizeof(hdr.fs_hostname));
 128         strncat(hdr.fs_device_name, device_name, sizeof(hdr.fs_device_name));
 129         hdr.fs_device_name[sizeof(hdr.fs_device_name) - 1] = 0;
 130         hdr.fs_blocksize = fs->blocksize;
 131
 132         if (stat(device_name, &st) == 0)
 133                 hdr.fs_device = st.st_rdev;
 134
 135         if (fstat(fd, &st) == 0) {
 136                 hdr.image_device = st.st_dev;
 137                 hdr.image_inode = st.st_ino;
 138         }
 139         memcpy(hdr.fs_uuid, fs->super->s_uuid, sizeof(hdr.fs_uuid));
 140
 141         hdr.image_time = time(0);
 142         write_header(fd, &hdr, fs->blocksize);
 143 }
 144
 145 /*
 146  * These set of functions are used to write a RAW image file.
 147  */
 148 ext2fs_block_bitmap meta_block_map;
 149
 150 struct process_block_struct {
 151         ext2_ino_t      ino;
 152 };
 153
 154 /*
 155  * These subroutines short circuits ext2fs_get_blocks and
 156  * ext2fs_check_directory; we use them since we already have the inode
 157  * structure, so there's no point in letting the ext2fs library read
 158  * the inode again.
 159  */
 160 static ino_t stashed_ino = 0;
 161 static struct ext2_inode *stashed_inode;
 162
 163 static errcode_t meta_get_blocks(ext2_filsys fs EXT2FS_ATTR((unused)),
 164                                  ext2_ino_t ino,
 165                                  blk_t *blocks)
 166 {
 167         int     i;
 168
 169         if ((ino != stashed_ino) || !stashed_inode)
 170                 return EXT2_ET_CALLBACK_NOTHANDLED;
 171
 172         for (i=0; i < EXT2_N_BLOCKS; i++)
 173                 blocks[i] = stashed_inode->i_block[i];
 174         return 0;
 175 }
 176
 177 static errcode_t meta_check_directory(ext2_filsys fs EXT2FS_ATTR((unused)),
 178                                       ext2_ino_t ino)
 179 {
 180         if ((ino != stashed_ino) || !stashed_inode)
 181                 return EXT2_ET_CALLBACK_NOTHANDLED;
 182
 183         if (!LINUX_S_ISDIR(stashed_inode->i_mode))
 184                 return EXT2_ET_NO_DIRECTORY;
 185         return 0;
 186 }
 187
 188 static errcode_t meta_read_inode(ext2_filsys fs EXT2FS_ATTR((unused)),
 189                                  ext2_ino_t ino,
 190                                  struct ext2_inode *inode)
 191 {
 192         if ((ino != stashed_ino) || !stashed_inode)
 193                 return EXT2_ET_CALLBACK_NOTHANDLED;
 194         *inode = *stashed_inode;
 195         return 0;
 196 }
 197
 198 static void use_inode_shortcuts(ext2_filsys fs, int bool)
 199 {
 200         if (bool) {
 201                 fs->get_blocks = meta_get_blocks;
 202                 fs->check_directory = meta_check_directory;
 203                 fs->read_inode = meta_read_inode;
 204                 stashed_ino = 0;
 205         } else {
 206                 fs->get_blocks = 0;
 207                 fs->check_directory = 0;
 208                 fs->read_inode = 0;
 209         }
 210 }
 211
 212 static int process_dir_block(ext2_filsys fs EXT2FS_ATTR((unused)),
 213                              blk_t *block_nr,
 214                              e2_blkcnt_t blockcnt EXT2FS_ATTR((unused)),
 215                              blk_t ref_block EXT2FS_ATTR((unused)),
 216                              int ref_offset EXT2FS_ATTR((unused)),
 217                              void *priv_data EXT2FS_ATTR((unused)))
 218 {
 219         ext2fs_mark_block_bitmap(meta_block_map, *block_nr);
 220         return 0;
 221 }
 222
 223 static int process_file_block(ext2_filsys fs EXT2FS_ATTR((unused)),
 224                               blk_t *block_nr,
 225                               e2_blkcnt_t blockcnt,
 226                               blk_t ref_block EXT2FS_ATTR((unused)),
 227                               int ref_offset EXT2FS_ATTR((unused)),
 228                               void *priv_data EXT2FS_ATTR((unused)))
 229 {
 230         if (blockcnt < 0) {
 231                 ext2fs_mark_block_bitmap(meta_block_map, *block_nr);
 232         }
 233         return 0;
 234 }
 235
 236 static void mark_table_blocks(ext2_filsys fs)
 237 {
 238         blk_t   block, b;
 239         unsigned int    i,j;
 240
 241         block = fs->super->s_first_data_block;
 242         /*
 243          * Mark primary superblock
 244          */
 245         ext2fs_mark_block_bitmap(meta_block_map, block);
 246
 247         /*
 248          * Mark the primary superblock descriptors
 249          */
 250         for (j = 0; j < fs->desc_blocks; j++) {
 251                 ext2fs_mark_block_bitmap(meta_block_map,
 252                          ext2fs_descriptor_block_loc(fs, block, j));
 253         }
 254
 255         for (i = 0; i < fs->group_desc_count; i++) {
 256                 /*
 257                  * Mark the blocks used for the inode table
 258                  */
 259                 if (fs->group_desc[i].bg_inode_table) {
 260                         for (j = 0, b = fs->group_desc[i].bg_inode_table;
 261                              j < (unsigned) fs->inode_blocks_per_group;
 262                              j++, b++)
 263                                 ext2fs_mark_block_bitmap(meta_block_map, b);
 264                 }
 265
 266                 /*
 267                  * Mark block used for the block bitmap
 268                  */
 269                 if (fs->group_desc[i].bg_block_bitmap) {
 270                         ext2fs_mark_block_bitmap(meta_block_map,
 271                                      fs->group_desc[i].bg_block_bitmap);
 272                 }
 273
 274                 /*
 275                  * Mark block used for the inode bitmap
 276                  */
 277                 if (fs->group_desc[i].bg_inode_bitmap) {
 278                         ext2fs_mark_block_bitmap(meta_block_map,
 279                                  fs->group_desc[i].bg_inode_bitmap);
 280                 }
 281                 block += fs->super->s_blocks_per_group;
 282         }
 283 }
 284
 285 /*
 286  * This function returns 1 if the specified block is all zeros
 287  */
 288 static int check_zero_block(char *buf, int blocksize)
 289 {
 290         char    *cp = buf;
 291         int     left = blocksize;
 292
 293         while (left > 0) {
 294                 if (*cp++)
 295                         return 0;
 296                 left--;
 297         }
 298         return 1;
 299 }
 300
 301 static void write_block(int fd, char *buf, int sparse_offset,
 302                         int blocksize, blk_t block)
 303 {
 304         int             count;
 305         errcode_t       err;
 306
 307         if (sparse_offset) {
 308 #ifdef HAVE_LSEEK64
 309                 if (lseek64(fd, sparse_offset, SEEK_CUR) < 0)
 310                         perror("lseek");
 311 #else
 312                 if (lseek(fd, sparse_offset, SEEK_CUR) < 0)
 313                         perror("lseek");
 314 #endif
 315         }
 316         if (blocksize) {
 317                 count = write(fd, buf, blocksize);
 318                 if (count != blocksize) {
 319                         if (count == -1)
 320                                 err = errno;
 321                         else
 322                                 err = 0;
 323                         com_err(program_name, err, "error writing block %d",
 324                                 block);
 325                 }
 326         }
 327 }
 328
 329 static void output_meta_data_blocks(ext2_filsys fs, int fd)
 330 {
 331         errcode_t       retval;
 332         blk_t           blk;
 333         char            buf[8192], zero_buf[8192];
 334         int             sparse = 0;
 335
 336         memset(zero_buf, 0, sizeof(zero_buf));
 337         for (blk = 0; blk < fs->super->s_blocks_count; blk++) {
 338                 if ((blk >= fs->super->s_first_data_block) &&
 339                     ext2fs_test_block_bitmap(meta_block_map, blk)) {
 340                         retval = io_channel_read_blk(fs->io, blk, 1, buf);
 341                         if (retval) {
 342                                 com_err(program_name, retval,
 343                                         "error reading block %d", blk);
 344                         }
 345                         if ((fd != 1) && check_zero_block(buf, fs->blocksize))
 346                                 goto sparse_write;
 347                         write_block(fd, buf, sparse, fs->blocksize, blk);
 348                         sparse = 0;
 349                 } else {
 350                 sparse_write:
 351                         if (fd == 1) {
 352                                 write_block(fd, zero_buf, 0,
 353                                             fs->blocksize, blk);
 354                                 continue;
 355                         }
 356                         sparse += fs->blocksize;
 357                         if (sparse >= 1024*1024) {
 358                                 write_block(fd, 0, sparse, 0, 0);
 359                                 sparse = 0;
 360                         }
 361                 }
 362         }
 363         write_block(fd, zero_buf, sparse, 1, -1);
 364 }
 365
 366 static void write_raw_image_file(ext2_filsys fs, int fd)
 367 {
 368         struct process_block_struct     pb;
 369         struct ext2_inode               inode;
 370         ext2_inode_scan                 scan;
 371         ext2_ino_t                      ino;
 372         errcode_t                       retval;
 373         char *                          block_buf;
 374
 375         retval = ext2fs_allocate_block_bitmap(fs, "in-use block map",
 376                                               &meta_block_map);
 377         if (retval) {
 378                 com_err(program_name, retval, "while allocating block bitmap");
 379                 exit(1);
 380         }
 381
 382         mark_table_blocks(fs);
 383
 384         retval = ext2fs_open_inode_scan(fs, 0, &scan);
 385         if (retval) {
 386                 com_err(program_name, retval, _("while opening inode scan"));
 387                 exit(1);
 388         }
 389
 390         block_buf = malloc(fs->blocksize * 3);
 391         if (!block_buf) {
 392                 com_err(program_name, 0, "Can't allocate block buffer");
 393                 exit(1);
 394         }
 395
 396         use_inode_shortcuts(fs, 1);
 397         stashed_inode = &inode;
 398         while (1) {
 399                 retval = ext2fs_get_next_inode(scan, &ino, &inode);
 400                 if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
 401                         continue;
 402                 if (retval) {
 403                         com_err(program_name, retval,
 404                                 _("while getting next inode"));
 405                         exit(1);
 406                 }
 407                 if (ino == 0)
 408                         break;
 409                 if (!inode.i_links_count)
 410                         continue;
 411                 if (inode.i_file_acl) {
 412                         ext2fs_mark_block_bitmap(meta_block_map,
 413                                                  inode.i_file_acl);
 414                 }
 415                 if (!ext2fs_inode_has_valid_blocks(&inode))
 416                         continue;
 417
 418                 stashed_ino = ino;
 419                 if (LINUX_S_ISDIR(inode.i_mode) ||
 420                     (LINUX_S_ISLNK(inode.i_mode) &&
 421                      ext2fs_inode_has_valid_blocks(&inode)) ||
 422                     ino == fs->super->s_journal_inum) {
 423                         retval = ext2fs_block_iterate2(fs, ino, 0,
 424                                        block_buf, process_dir_block, &pb);
 425                         if (retval) {
 426                                 com_err(program_name, retval,
 427                                         "while iterating over inode %d",
 428                                         ino);
 429                                 exit(1);
 430                         }
 431                 } else {
 432                         if (inode.i_block[EXT2_IND_BLOCK] ||
 433                             inode.i_block[EXT2_DIND_BLOCK] ||
 434                             inode.i_block[EXT2_TIND_BLOCK]) {
 435                                 retval = ext2fs_block_iterate2(fs,
 436                                        ino, 0, block_buf,
 437                                        process_file_block, &pb);
 438                                 if (retval) {
 439                                         com_err(program_name, retval,
 440                                         "while iterating over %d", ino);
 441                                         exit(1);
 442                                 }
 443                         }
 444                 }
 445         }
 446         use_inode_shortcuts(fs, 0);
 447         output_meta_data_blocks(fs, fd);
 448 }
 449
 450 int main (int argc, char ** argv)
 451 {
 452         int c;
 453         errcode_t retval;
 454         ext2_filsys fs;
 455         char *outfn;
 456         int open_flag = 0;
 457         int raw_flag = 0;
 458         int fd = 0;
 459
 460 #ifdef ENABLE_NLS
 461         setlocale(LC_MESSAGES, "");
 462         setlocale(LC_CTYPE, "");
 463         bindtextdomain(NLS_CAT_NAME, LOCALEDIR);
 464         textdomain(NLS_CAT_NAME);
 465 #endif
 466         fprintf (stderr, "e2image %s (%s)\n", E2FSPROGS_VERSION,
 467                  E2FSPROGS_DATE);
 468         if (argc && *argv)
 469                 program_name = *argv;
 470         initialize_ext2_error_table();
 471         while ((c = getopt (argc, argv, "r")) != EOF)
 472                 switch (c) {
 473                 case 'r':
 474                         raw_flag++;
 475                         break;
 476                 default:
 477                         usage();
 478                 }
 479         if (optind != argc - 2 )
 480                 usage();
 481         device_name = argv[optind];
 482         outfn = argv[optind+1];
 483         retval = ext2fs_open (device_name, open_flag, 0, 0,
 484                               unix_io_manager, &fs);
 485         if (retval) {
 486                 com_err (program_name, retval, _("while trying to open %s"),
 487                          device_name);
 488                 fputs(_("Couldn't find valid filesystem superblock.\n"), stdout);
 489                 exit(1);
 490         }
 491
 492         if (strcmp(outfn, "-") == 0)
 493                 fd = 1;
 494         else {
 495 #ifdef HAVE_OPEN64
 496                 fd = open64(outfn, O_CREAT|O_TRUNC|O_WRONLY, 0600);
 497 #else
 498                 fd = open(outfn, O_CREAT|O_TRUNC|O_WRONLY, 0600);
 499 #endif
 500                 if (fd < 0) {
 501                         com_err(program_name, errno,
 502                                 _("while trying to open %s"), argv[optind+1]);
 503                         exit(1);
 504                 }
 505         }
 506
 507         if (raw_flag)
 508                 write_raw_image_file(fs, fd);
 509         else
 510                 write_image_file(fs, fd);
 511
 512         ext2fs_close (fs);
 513         exit (0);
 514 }