misc/e2undo.c

   1 /*
   2  * e2undo.c - Replay an undo log onto an ext2/3/4 filesystem
   3  *
   4  * Copyright IBM Corporation, 2007
   5  * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
   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 #include "config.h"
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #ifdef HAVE_GETOPT_H
  17 #include <getopt.h>
  18 #endif
  19 #include <fcntl.h>
  20 #if HAVE_ERRNO_H
  21 #include <errno.h>
  22 #endif
  23 #include <unistd.h>
  24 #include <libgen.h>
  25 #include "ext2fs/ext2fs.h"
  26 #include "support/nls-enable.h"
  27
  28 #undef DEBUG
  29
  30 #ifdef DEBUG
  31 # define dbg_printf(f, a...)  do {printf(f, ## a); fflush(stdout); } while (0)
  32 #else
  33 # define dbg_printf(f, a...)
  34 #endif
  35
  36 /*
  37  * Undo file format: The file is cut up into undo_header.block_size blocks.
  38  * The first block contains the header.
  39  * The second block contains the superblock.
  40  * There is then a repeating series of blocks as follows:
  41  *   A key block, which contains undo_keys to map the following data blocks.
  42  *   Data blocks
  43  * (Note that there are pointers to the first key block and the sb, so this
  44  * order isn't strictly necessary.)
  45  */
  46 #define E2UNDO_MAGIC "E2UNDO02"
  47 #define KEYBLOCK_MAGIC 0xCADECADE
  48
  49 #define E2UNDO_STATE_FINISHED   0x1     /* undo file is complete */
  50
  51 #define E2UNDO_MIN_BLOCK_SIZE   1024    /* undo blocks are no less than 1KB */
  52 #define E2UNDO_MAX_BLOCK_SIZE   1048576 /* undo blocks are no more than 1MB */
  53
  54 struct undo_header {
  55         char magic[8];          /* "E2UNDO02" */
  56         __le64 num_keys;        /* how many keys? */
  57         __le64 super_offset;    /* where in the file is the superblock copy? */
  58         __le64 key_offset;      /* where do the key/data block chunks start? */
  59         __le32 block_size;      /* block size of the undo file */
  60         __le32 fs_block_size;   /* block size of the target device */
  61         __le32 sb_crc;          /* crc32c of the superblock */
  62         __le32 state;           /* e2undo state flags */
  63         __le32 f_compat;        /* compatible features (none so far) */
  64         __le32 f_incompat;      /* incompatible features (none so far) */
  65         __le32 f_rocompat;      /* ro compatible features (none so far) */
  66         __le32 pad32;           /* padding for fs_offset */
  67         __le64 fs_offset;       /* filesystem offset */
  68         __u8 padding[436];      /* padding */
  69         __le32 header_crc;      /* crc32c of the header (but not this field) */
  70 };
  71
  72 #define E2UNDO_MAX_EXTENT_BLOCKS        512     /* max extent size, in blocks */
  73
  74 struct undo_key {
  75         __le64 fsblk;           /* where in the fs does the block go */
  76         __le32 blk_crc;         /* crc32c of the block */
  77         __le32 size;            /* how many bytes in this block? */
  78 };
  79
  80 struct undo_key_block {
  81         __le32 magic;           /* KEYBLOCK_MAGIC number */
  82         __le32 crc;             /* block checksum */
  83         __le64 reserved;        /* zero */
  84 #if __GNUC_PREREQ (4, 8)
  85 #pragma GCC diagnostic push
  86 #pragma GCC diagnostic ignored "-Wpedantic"
  87 #endif
  88         struct undo_key keys[0];        /* keys, which come immediately after */
  89 #if __GNUC_PREREQ (4, 8)
  90 #pragma GCC diagnostic pop
  91 #endif
  92 };
  93
  94 struct undo_key_info {
  95         blk64_t fsblk;
  96         blk64_t fileblk;
  97         __u32 blk_crc;
  98         unsigned int size;
  99 };
 100
 101 struct undo_context {
 102         struct undo_header hdr;
 103         io_channel undo_file;
 104         unsigned int blocksize, fs_blocksize;
 105         blk64_t super_block;
 106         size_t num_keys;
 107         struct undo_key_info *keys;
 108 };
 109 #define KEYS_PER_BLOCK(d) (((d)->blocksize / sizeof(struct undo_key)) - 1)
 110
 111 #define E2UNDO_FEATURE_COMPAT_FS_OFFSET 0x1     /* the filesystem offset */
 112
 113 static inline int e2undo_has_feature_fs_offset(struct undo_header *header) {
 114         return ext2fs_le32_to_cpu(header->f_compat) &
 115                 E2UNDO_FEATURE_COMPAT_FS_OFFSET;
 116 }
 117
 118 static char *prg_name;
 119 static char *undo_file;
 120
 121 static void usage(void)
 122 {
 123         fprintf(stderr,
 124                 _("Usage: %s [-f] [-h] [-n] [-o offset] [-v] [-z undo_file] <transaction file> <filesystem>\n"), prg_name);
 125         exit(1);
 126 }
 127
 128 static void dump_header(struct undo_header *hdr)
 129 {
 130         printf("nr keys:\t%llu\n", ext2fs_le64_to_cpu(hdr->num_keys));
 131         printf("super block:\t%llu\n", ext2fs_le64_to_cpu(hdr->super_offset));
 132         printf("key block:\t%llu\n", ext2fs_le64_to_cpu(hdr->key_offset));
 133         printf("block size:\t%u\n", ext2fs_le32_to_cpu(hdr->block_size));
 134         printf("fs block size:\t%u\n", ext2fs_le32_to_cpu(hdr->fs_block_size));
 135         printf("super crc:\t0x%x\n", ext2fs_le32_to_cpu(hdr->sb_crc));
 136         printf("state:\t\t0x%x\n", ext2fs_le32_to_cpu(hdr->state));
 137         printf("compat:\t\t0x%x\n", ext2fs_le32_to_cpu(hdr->f_compat));
 138         printf("incompat:\t0x%x\n", ext2fs_le32_to_cpu(hdr->f_incompat));
 139         printf("rocompat:\t0x%x\n", ext2fs_le32_to_cpu(hdr->f_rocompat));
 140         if (e2undo_has_feature_fs_offset(hdr))
 141                 printf("fs offset:\t%llu\n", ext2fs_le64_to_cpu(hdr->fs_offset));
 142         printf("header crc:\t0x%x\n", ext2fs_le32_to_cpu(hdr->header_crc));
 143 }
 144
 145 static void print_undo_mismatch(struct ext2_super_block *fs_super,
 146                                 struct ext2_super_block *undo_super)
 147 {
 148         printf("%s",
 149                _("The file system superblock doesn't match the undo file.\n"));
 150         if (memcmp(fs_super->s_uuid, undo_super->s_uuid,
 151                    sizeof(fs_super->s_uuid)))
 152                 printf("%s", _("UUID does not match.\n"));
 153         if (fs_super->s_mtime != undo_super->s_mtime)
 154                 printf("%s", _("Last mount time does not match.\n"));
 155         if (fs_super->s_wtime != undo_super->s_wtime)
 156                 printf("%s", _("Last write time does not match.\n"));
 157         if (fs_super->s_kbytes_written != undo_super->s_kbytes_written)
 158                 printf("%s", _("Lifetime write counter does not match.\n"));
 159 }
 160
 161 static int check_filesystem(struct undo_context *ctx, io_channel channel)
 162 {
 163         struct ext2_super_block super, *sb;
 164         char *buf;
 165         __u32 sb_crc;
 166         errcode_t retval;
 167
 168         io_channel_set_blksize(channel, SUPERBLOCK_OFFSET);
 169         retval = io_channel_read_blk64(channel, 1, -SUPERBLOCK_SIZE, &super);
 170         if (retval) {
 171                 com_err(prg_name, retval,
 172                         "%s", _("while reading filesystem superblock."));
 173                 return retval;
 174         }
 175
 176         /*
 177          * Compare the FS and the undo file superblock so that we can't apply
 178          * e2undo "patches" out of order.
 179          */
 180         retval = ext2fs_get_mem(ctx->blocksize, &buf);
 181         if (retval) {
 182                 com_err(prg_name, retval, "%s", _("while allocating memory"));
 183                 return retval;
 184         }
 185         retval = io_channel_read_blk64(ctx->undo_file, ctx->super_block,
 186                                        -SUPERBLOCK_SIZE, buf);
 187         if (retval) {
 188                 com_err(prg_name, retval, "%s", _("while fetching superblock"));
 189                 goto out;
 190         }
 191         sb = (struct ext2_super_block *)buf;
 192         sb->s_magic = ~sb->s_magic;
 193         if (memcmp(&super, buf, sizeof(super))) {
 194                 print_undo_mismatch(&super, (struct ext2_super_block *)buf);
 195                 retval = -1;
 196                 goto out;
 197         }
 198         sb_crc = ext2fs_crc32c_le(~0, (unsigned char *)buf, SUPERBLOCK_SIZE);
 199         if (ext2fs_le32_to_cpu(ctx->hdr.sb_crc) != sb_crc) {
 200                 fprintf(stderr,
 201                         _("Undo file superblock checksum doesn't match.\n"));
 202                 retval = -1;
 203                 goto out;
 204         }
 205
 206 out:
 207         ext2fs_free_mem(&buf);
 208         return retval;
 209 }
 210
 211 static int key_compare(const void *a, const void *b)
 212 {
 213         const struct undo_key_info *ka, *kb;
 214
 215         ka = a;
 216         kb = b;
 217         return ka->fsblk - kb->fsblk;
 218 }
 219
 220 static int e2undo_setup_tdb(const char *name, io_manager *io_ptr)
 221 {
 222         errcode_t retval = 0;
 223         const char *tdb_dir;
 224         char *tdb_file = NULL;
 225         char *dev_name, *tmp_name;
 226
 227         /* (re)open a specific undo file */
 228         if (undo_file && undo_file[0] != 0) {
 229                 retval = set_undo_io_backing_manager(*io_ptr);
 230                 if (retval)
 231                         goto err;
 232                 *io_ptr = undo_io_manager;
 233                 retval = set_undo_io_backup_file(undo_file);
 234                 if (retval)
 235                         goto err;
 236                 printf(_("Overwriting existing filesystem; this can be undone "
 237                          "using the command:\n"
 238                          "    e2undo %s %s\n\n"),
 239                          undo_file, name);
 240                 return retval;
 241         }
 242
 243         /*
 244          * Configuration via a conf file would be
 245          * nice
 246          */
 247         tdb_dir = getenv("E2FSPROGS_UNDO_DIR");
 248         if (!tdb_dir)
 249                 tdb_dir = "/var/lib/e2fsprogs";
 250
 251         if (!strcmp(tdb_dir, "none") || (tdb_dir[0] == 0) ||
 252             access(tdb_dir, W_OK))
 253                 return 0;
 254
 255         tmp_name = strdup(name);
 256         if (!tmp_name)
 257                 goto errout;
 258         dev_name = basename(tmp_name);
 259         tdb_file = malloc(strlen(tdb_dir) + 8 + strlen(dev_name) + 7 + 1);
 260         if (!tdb_file) {
 261                 free(tmp_name);
 262                 goto errout;
 263         }
 264         sprintf(tdb_file, "%s/e2undo-%s.e2undo", tdb_dir, dev_name);
 265         free(tmp_name);
 266
 267         if ((unlink(tdb_file) < 0) && (errno != ENOENT)) {
 268                 retval = errno;
 269                 com_err(prg_name, retval,
 270                         _("while trying to delete %s"), tdb_file);
 271                 goto errout;
 272         }
 273
 274         retval = set_undo_io_backing_manager(*io_ptr);
 275         if (retval)
 276                 goto errout;
 277         *io_ptr = undo_io_manager;
 278         retval = set_undo_io_backup_file(tdb_file);
 279         if (retval)
 280                 goto errout;
 281         printf(_("Overwriting existing filesystem; this can be undone "
 282                  "using the command:\n"
 283                  "    e2undo %s %s\n\n"),
 284                  tdb_file, name);
 285
 286         free(tdb_file);
 287         return 0;
 288 errout:
 289         free(tdb_file);
 290 err:
 291         com_err(prg_name, retval, "while trying to setup undo file\n");
 292         return retval;
 293 }
 294
 295 int main(int argc, char *argv[])
 296 {
 297         int c, force = 0, dry_run = 0, verbose = 0, dump = 0;
 298         io_channel channel;
 299         errcode_t retval;
 300         int mount_flags, csum_error = 0, io_error = 0;
 301         size_t i, keys_per_block;
 302         char *device_name, *tdb_file;
 303         io_manager manager = unix_io_manager;
 304         struct undo_context undo_ctx;
 305         char *buf;
 306         struct undo_key_block *keyb;
 307         struct undo_key *dkey;
 308         struct undo_key_info *ikey;
 309         __u32 key_crc, blk_crc, hdr_crc;
 310         blk64_t lblk;
 311         ext2_filsys fs;
 312         __u64 offset = 0;
 313         char opt_offset_string[40] = { 0 };
 314
 315 #ifdef ENABLE_NLS
 316         setlocale(LC_MESSAGES, "");
 317         setlocale(LC_CTYPE, "");
 318         bindtextdomain(NLS_CAT_NAME, LOCALEDIR);
 319         textdomain(NLS_CAT_NAME);
 320         set_com_err_gettext(gettext);
 321 #endif
 322         add_error_table(&et_ext2_error_table);
 323
 324         prg_name = argv[0];
 325         while ((c = getopt(argc, argv, "fhno:vz:")) != EOF) {
 326                 switch (c) {
 327                 case 'f':
 328                         force = 1;
 329                         break;
 330                 case 'h':
 331                         dump = 1;
 332                         break;
 333                 case 'n':
 334                         dry_run = 1;
 335                         break;
 336                 case 'o':
 337                         offset = strtoull(optarg, &buf, 0);
 338                         if (*buf) {
 339                                 com_err(prg_name, 0,
 340                                                 _("illegal offset - %s"), optarg);
 341                                 exit(1);
 342                         }
 343                         /* used to indicate that an offset was specified */
 344                         opt_offset_string[0] = 1;
 345                         break;
 346                 case 'v':
 347                         verbose = 1;
 348                         break;
 349                 case 'z':
 350                         undo_file = optarg;
 351                         break;
 352                 default:
 353                         usage();
 354                 }
 355         }
 356
 357         if (argc != optind + 2)
 358                 usage();
 359
 360         tdb_file = argv[optind];
 361         device_name = argv[optind+1];
 362
 363         if (undo_file && strcmp(tdb_file, undo_file) == 0) {
 364                 printf(_("Will not write to an undo file while replaying it.\n"));
 365                 exit(1);
 366         }
 367
 368         /* Interpret the undo file */
 369         retval = manager->open(tdb_file, IO_FLAG_EXCLUSIVE,
 370                                &undo_ctx.undo_file);
 371         if (retval) {
 372                 com_err(prg_name, errno,
 373                                 _("while opening undo file `%s'\n"), tdb_file);
 374                 exit(1);
 375         }
 376         retval = io_channel_read_blk64(undo_ctx.undo_file, 0,
 377                                        -(int)sizeof(undo_ctx.hdr),
 378                                        &undo_ctx.hdr);
 379         if (retval) {
 380                 com_err(prg_name, retval, _("while reading undo file"));
 381                 exit(1);
 382         }
 383         if (memcmp(undo_ctx.hdr.magic, E2UNDO_MAGIC,
 384                     sizeof(undo_ctx.hdr.magic))) {
 385                 fprintf(stderr, _("%s: Not an undo file.\n"), tdb_file);
 386                 exit(1);
 387         }
 388         if (dump) {
 389                 dump_header(&undo_ctx.hdr);
 390                 exit(1);
 391         }
 392         hdr_crc = ext2fs_crc32c_le(~0, (unsigned char *)&undo_ctx.hdr,
 393                                    sizeof(struct undo_header) -
 394                                    sizeof(__u32));
 395         if (!force && ext2fs_le32_to_cpu(undo_ctx.hdr.header_crc) != hdr_crc) {
 396                 fprintf(stderr, _("%s: Header checksum doesn't match.\n"),
 397                         tdb_file);
 398                 exit(1);
 399         }
 400         undo_ctx.blocksize = ext2fs_le32_to_cpu(undo_ctx.hdr.block_size);
 401         undo_ctx.fs_blocksize = ext2fs_le32_to_cpu(undo_ctx.hdr.fs_block_size);
 402         if (undo_ctx.blocksize == 0 || undo_ctx.fs_blocksize == 0) {
 403                 fprintf(stderr, _("%s: Corrupt undo file header.\n"), tdb_file);
 404                 exit(1);
 405         }
 406         if (!force && undo_ctx.blocksize > E2UNDO_MAX_BLOCK_SIZE) {
 407                 fprintf(stderr, _("%s: Undo block size too large.\n"),
 408                         tdb_file);
 409                 exit(1);
 410         }
 411         if (!force && undo_ctx.blocksize < E2UNDO_MIN_BLOCK_SIZE) {
 412                 fprintf(stderr, _("%s: Undo block size too small.\n"),
 413                         tdb_file);
 414                 exit(1);
 415         }
 416         undo_ctx.super_block = ext2fs_le64_to_cpu(undo_ctx.hdr.super_offset);
 417         undo_ctx.num_keys = ext2fs_le64_to_cpu(undo_ctx.hdr.num_keys);
 418         io_channel_set_blksize(undo_ctx.undo_file, undo_ctx.blocksize);
 419         /*
 420          * Do not compare undo_ctx.hdr.f_compat with the available compatible
 421          * features set, because a "missing" compatible feature should
 422          * not cause any problems.
 423          */
 424         if (!force && (undo_ctx.hdr.f_incompat || undo_ctx.hdr.f_rocompat)) {
 425                 fprintf(stderr, _("%s: Unknown undo file feature set.\n"),
 426                         tdb_file);
 427                 exit(1);
 428         }
 429
 430         /* open the fs */
 431         retval = ext2fs_check_if_mounted(device_name, &mount_flags);
 432         if (retval) {
 433                 com_err(prg_name, retval, _("Error while determining whether "
 434                                 "%s is mounted."), device_name);
 435                 exit(1);
 436         }
 437
 438         if (mount_flags & EXT2_MF_MOUNTED) {
 439                 com_err(prg_name, retval, "%s", _("e2undo should only be run "
 440                                                 "on unmounted filesystems"));
 441                 exit(1);
 442         }
 443
 444         if (undo_file) {
 445                 retval = e2undo_setup_tdb(device_name, &manager);
 446                 if (retval)
 447                         exit(1);
 448         }
 449
 450         retval = manager->open(device_name,
 451                                IO_FLAG_EXCLUSIVE | (dry_run ? 0 : IO_FLAG_RW),
 452                                &channel);
 453         if (retval) {
 454                 com_err(prg_name, retval,
 455                                 _("while opening `%s'"), device_name);
 456                 exit(1);
 457         }
 458
 459         if (*opt_offset_string || e2undo_has_feature_fs_offset(&undo_ctx.hdr)) {
 460                 if (!*opt_offset_string)
 461                         offset = ext2fs_le64_to_cpu(undo_ctx.hdr.fs_offset);
 462                 retval = snprintf(opt_offset_string, sizeof(opt_offset_string),
 463                                                   "offset=%llu", offset);
 464                 if ((size_t) retval >= sizeof(opt_offset_string)) {
 465                         /* should not happen... */
 466                         com_err(prg_name, 0, _("specified offset is too large"));
 467                         exit(1);
 468                 }
 469                 io_channel_set_options(channel, opt_offset_string);
 470         }
 471
 472         if (!force && check_filesystem(&undo_ctx, channel))
 473                 exit(1);
 474
 475         /* prepare to read keys */
 476         retval = ext2fs_get_mem(sizeof(struct undo_key_info) * undo_ctx.num_keys,
 477                                 &undo_ctx.keys);
 478         if (retval) {
 479                 com_err(prg_name, retval, "%s", _("while allocating memory"));
 480                 exit(1);
 481         }
 482         ikey = undo_ctx.keys;
 483         retval = ext2fs_get_mem(undo_ctx.blocksize, &keyb);
 484         if (retval) {
 485                 com_err(prg_name, retval, "%s", _("while allocating memory"));
 486                 exit(1);
 487         }
 488         retval = ext2fs_get_mem(E2UNDO_MAX_EXTENT_BLOCKS * undo_ctx.blocksize,
 489                                 &buf);
 490         if (retval) {
 491                 com_err(prg_name, retval, "%s", _("while allocating memory"));
 492                 exit(1);
 493         }
 494
 495         /* load keys */
 496         keys_per_block = KEYS_PER_BLOCK(&undo_ctx);
 497         lblk = ext2fs_le64_to_cpu(undo_ctx.hdr.key_offset);
 498         dbg_printf("nr_keys=%lu, kpb=%zu, blksz=%u\n",
 499                    undo_ctx.num_keys, keys_per_block, undo_ctx.blocksize);
 500         for (i = 0; i < undo_ctx.num_keys; i += keys_per_block) {
 501                 size_t j, max_j;
 502                 __le32 crc;
 503
 504                 retval = io_channel_read_blk64(undo_ctx.undo_file,
 505                                                lblk, 1, keyb);
 506                 if (retval) {
 507                         com_err(prg_name, retval, "%s", _("while reading keys"));
 508                         if (force) {
 509                                 io_error = 1;
 510                                 undo_ctx.num_keys = i - 1;
 511                                 break;
 512                         }
 513                         exit(1);
 514                 }
 515
 516                 /* check keys */
 517                 if (!force &&
 518                     ext2fs_le32_to_cpu(keyb->magic) != KEYBLOCK_MAGIC) {
 519                         fprintf(stderr, _("%s: wrong key magic at %llu\n"),
 520                                 tdb_file, lblk);
 521                         exit(1);
 522                 }
 523                 crc = keyb->crc;
 524                 keyb->crc = 0;
 525                 key_crc = ext2fs_crc32c_le(~0, (unsigned char *)keyb,
 526                                            undo_ctx.blocksize);
 527                 if (!force && ext2fs_le32_to_cpu(crc) != key_crc) {
 528                         fprintf(stderr,
 529                                 _("%s: key block checksum error at %llu.\n"),
 530                                 tdb_file, lblk);
 531                         exit(1);
 532                 }
 533
 534                 /* load keys from key block */
 535                 lblk++;
 536                 max_j = undo_ctx.num_keys - i;
 537                 if (max_j > keys_per_block)
 538                         max_j = keys_per_block;
 539                 for (j = 0, dkey = keyb->keys;
 540                      j < max_j;
 541                      j++, ikey++, dkey++) {
 542                         ikey->fsblk = ext2fs_le64_to_cpu(dkey->fsblk);
 543                         ikey->fileblk = lblk;
 544                         ikey->blk_crc = ext2fs_le32_to_cpu(dkey->blk_crc);
 545                         ikey->size = ext2fs_le32_to_cpu(dkey->size);
 546                         lblk += (ikey->size + undo_ctx.blocksize - 1) /
 547                                 undo_ctx.blocksize;
 548
 549                         if (E2UNDO_MAX_EXTENT_BLOCKS * undo_ctx.blocksize <
 550                             ikey->size) {
 551                                 com_err(prg_name, retval,
 552                                         _("%s: block %llu is too long."),
 553                                         tdb_file, ikey->fsblk);
 554                                 exit(1);
 555                         }
 556
 557                         /* check each block's crc */
 558                         retval = io_channel_read_blk64(undo_ctx.undo_file,
 559                                                        ikey->fileblk,
 560                                                        -(int)ikey->size,
 561                                                        buf);
 562                         if (retval) {
 563                                 com_err(prg_name, retval,
 564                                         _("while fetching block %llu."),
 565                                         ikey->fileblk);
 566                                 if (!force)
 567                                         exit(1);
 568                                 io_error = 1;
 569                                 continue;
 570                         }
 571
 572                         blk_crc = ext2fs_crc32c_le(~0, (unsigned char *)buf,
 573                                                    ikey->size);
 574                         if (blk_crc != ikey->blk_crc) {
 575                                 fprintf(stderr,
 576                                         _("checksum error in filesystem block "
 577                                           "%llu (undo blk %llu)\n"),
 578                                         ikey->fsblk, ikey->fileblk);
 579                                 if (!force)
 580                                         exit(1);
 581                                 csum_error = 1;
 582                         }
 583                 }
 584         }
 585         ext2fs_free_mem(&keyb);
 586
 587         /* sort keys in fs block order */
 588         qsort(undo_ctx.keys, undo_ctx.num_keys, sizeof(struct undo_key_info),
 589               key_compare);
 590
 591         /* replay */
 592         io_channel_set_blksize(channel, undo_ctx.fs_blocksize);
 593         for (i = 0, ikey = undo_ctx.keys; i < undo_ctx.num_keys; i++, ikey++) {
 594                 retval = io_channel_read_blk64(undo_ctx.undo_file,
 595                                                ikey->fileblk,
 596                                                -(int)ikey->size,
 597                                                buf);
 598                 if (retval) {
 599                         com_err(prg_name, retval,
 600                                 _("while fetching block %llu."),
 601                                 ikey->fileblk);
 602                         io_error = 1;
 603                         continue;
 604                 }
 605
 606                 if (verbose)
 607                         printf("Replayed block of size %u from %llu to %llu\n",
 608                                 ikey->size, ikey->fileblk, ikey->fsblk);
 609                 if (dry_run)
 610                         continue;
 611                 retval = io_channel_write_blk64(channel, ikey->fsblk,
 612                                                 -(int)ikey->size, buf);
 613                 if (retval) {
 614                         com_err(prg_name, retval,
 615                                 _("while writing block %llu."), ikey->fsblk);
 616                         io_error = 1;
 617                 }
 618         }
 619
 620         if (csum_error)
 621                 fprintf(stderr, _("Undo file corruption; run e2fsck NOW!\n"));
 622         if (io_error)
 623                 fprintf(stderr, _("IO error during replay; run e2fsck NOW!\n"));
 624         if (!(ext2fs_le32_to_cpu(undo_ctx.hdr.state) & E2UNDO_STATE_FINISHED)) {
 625                 force = 1;
 626                 fprintf(stderr, _("Incomplete undo record; run e2fsck.\n"));
 627         }
 628         ext2fs_free_mem(&buf);
 629         ext2fs_free_mem(&undo_ctx.keys);
 630         io_channel_close(channel);
 631
 632         /* If there were problems, try to force a fsck */
 633         if (!dry_run && (force || csum_error || io_error)) {
 634                 retval = ext2fs_open2(device_name, NULL,
 635                                    EXT2_FLAG_RW | EXT2_FLAG_64BITS, 0, 0,
 636                                    manager, &fs);
 637                 if (retval)
 638                         goto out;
 639                 fs->super->s_state &= ~EXT2_VALID_FS;
 640                 if (csum_error || io_error)
 641                         fs->super->s_state |= EXT2_ERROR_FS;
 642                 ext2fs_mark_super_dirty(fs);
 643                 ext2fs_close_free(&fs);
 644         }
 645
 646 out:
 647         io_channel_close(undo_ctx.undo_file);
 648
 649         return csum_error;
 650 }