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