e2fsck/recovery.c

   1 /*
   2  * linux/fs/jbd/recovery.c
   3  *
   4  * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
   5  *
   6  * Copyright 1999-2000 Red Hat Software --- All Rights Reserved
   7  *
   8  * This file is part of the Linux kernel and is made available under
   9  * the terms of the GNU General Public License, version 2, or at your
  10  * option, any later version, incorporated herein by reference.
  11  *
  12  * Journal recovery routines for the generic filesystem journaling code;
  13  * part of the ext2fs journaling system.
  14  */
  15
  16 #ifndef __KERNEL__
  17 #include "jfs_user.h"
  18 #else
  19 #include <linux/time.h>
  20 #include <linux/fs.h>
  21 #include <linux/jbd.h>
  22 #include <linux/errno.h>
  23 #include <linux/slab.h>
  24 #endif
  25
  26 /*
  27  * Maintain information about the progress of the recovery job, so that
  28  * the different passes can carry information between them.
  29  */
  30 struct recovery_info
  31 {
  32         tid_t           start_transaction;
  33         tid_t           end_transaction;
  34
  35         int             nr_replays;
  36         int             nr_revokes;
  37         int             nr_revoke_hits;
  38 };
  39
  40 enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY};
  41 static int do_one_pass(journal_t *journal,
  42                                 struct recovery_info *info, enum passtype pass);
  43 static int scan_revoke_records(journal_t *, struct buffer_head *,
  44                                 tid_t, struct recovery_info *);
  45
  46 #ifdef __KERNEL__
  47
  48 /* Release readahead buffers after use */
  49 static void journal_brelse_array(struct buffer_head *b[], int n)
  50 {
  51         while (--n >= 0)
  52                 brelse (b[n]);
  53 }
  54
  55
  56 /*
  57  * When reading from the journal, we are going through the block device
  58  * layer directly and so there is no readahead being done for us.  We
  59  * need to implement any readahead ourselves if we want it to happen at
  60  * all.  Recovery is basically one long sequential read, so make sure we
  61  * do the IO in reasonably large chunks.
  62  *
  63  * This is not so critical that we need to be enormously clever about
  64  * the readahead size, though.  128K is a purely arbitrary, good-enough
  65  * fixed value.
  66  */
  67
  68 #define MAXBUF 8
  69 static int do_readahead(journal_t *journal, unsigned int start)
  70 {
  71         int err;
  72         unsigned int max, nbufs, next;
  73         unsigned long long blocknr;
  74         struct buffer_head *bh;
  75
  76         struct buffer_head * bufs[MAXBUF];
  77
  78         /* Do up to 128K of readahead */
  79         max = start + (128 * 1024 / journal->j_blocksize);
  80         if (max > journal->j_maxlen)
  81                 max = journal->j_maxlen;
  82
  83         /* Do the readahead itself.  We'll submit MAXBUF buffer_heads at
  84          * a time to the block device IO layer. */
  85
  86         nbufs = 0;
  87
  88         for (next = start; next < max; next++) {
  89                 err = journal_bmap(journal, next, &blocknr);
  90
  91                 if (err) {
  92                         printk (KERN_ERR "JBD: bad block at offset %u\n",
  93                                 next);
  94                         goto failed;
  95                 }
  96
  97                 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
  98                 if (!bh) {
  99                         err = -ENOMEM;
 100                         goto failed;
 101                 }
 102
 103                 if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
 104                         bufs[nbufs++] = bh;
 105                         if (nbufs == MAXBUF) {
 106                                 ll_rw_block(READ, nbufs, bufs);
 107                                 journal_brelse_array(bufs, nbufs);
 108                                 nbufs = 0;
 109                         }
 110                 } else
 111                         brelse(bh);
 112         }
 113
 114         if (nbufs)
 115                 ll_rw_block(READ, nbufs, bufs);
 116         err = 0;
 117
 118 failed:
 119         if (nbufs)
 120                 journal_brelse_array(bufs, nbufs);
 121         return err;
 122 }
 123
 124 #endif /* __KERNEL__ */
 125
 126
 127 /*
 128  * Read a block from the journal
 129  */
 130
 131 static int jread(struct buffer_head **bhp, journal_t *journal,
 132                  unsigned int offset)
 133 {
 134         int err;
 135         unsigned long long blocknr;
 136         struct buffer_head *bh;
 137
 138         *bhp = NULL;
 139
 140         if (offset >= journal->j_maxlen) {
 141                 printk(KERN_ERR "JBD: corrupted journal superblock\n");
 142                 return -EIO;
 143         }
 144
 145         err = journal_bmap(journal, offset, &blocknr);
 146
 147         if (err) {
 148                 printk (KERN_ERR "JBD: bad block at offset %u\n",
 149                         offset);
 150                 return err;
 151         }
 152
 153         bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
 154         if (!bh)
 155                 return -ENOMEM;
 156
 157         if (!buffer_uptodate(bh)) {
 158                 /* If this is a brand new buffer, start readahead.
 159                    Otherwise, we assume we are already reading it.  */
 160                 if (!buffer_req(bh))
 161                         do_readahead(journal, offset);
 162                 wait_on_buffer(bh);
 163         }
 164
 165         if (!buffer_uptodate(bh)) {
 166                 printk (KERN_ERR "JBD: Failed to read block at offset %u\n",
 167                         offset);
 168                 brelse(bh);
 169                 return -EIO;
 170         }
 171
 172         *bhp = bh;
 173         return 0;
 174 }
 175
 176
 177 /*
 178  * Count the number of in-use tags in a journal descriptor block.
 179  */
 180
 181 static int count_tags(journal_t *journal, struct buffer_head *bh)
 182 {
 183         char *                  tagp;
 184         journal_block_tag_t *   tag;
 185         int                     nr = 0, size = journal->j_blocksize;
 186         int                     tag_bytes = journal_tag_bytes(journal);
 187
 188         tagp = &bh->b_data[sizeof(journal_header_t)];
 189
 190         while ((tagp - bh->b_data + tag_bytes) <= size) {
 191                 tag = (journal_block_tag_t *) tagp;
 192
 193                 nr++;
 194                 tagp += tag_bytes;
 195                 if (!(tag->t_flags & cpu_to_be32(JFS_FLAG_SAME_UUID)))
 196                         tagp += 16;
 197
 198                 if (tag->t_flags & cpu_to_be32(JFS_FLAG_LAST_TAG))
 199                         break;
 200         }
 201
 202         return nr;
 203 }
 204
 205
 206 /* Make sure we wrap around the log correctly! */
 207 #define wrap(journal, var)                                              \
 208 do {                                                                    \
 209         if (var >= (journal)->j_last)                                   \
 210                 var -= ((journal)->j_last - (journal)->j_first);        \
 211 } while (0)
 212
 213 /**
 214  * journal_recover - recovers a on-disk journal
 215  * @journal: the journal to recover
 216  *
 217  * The primary function for recovering the log contents when mounting a
 218  * journaled device.
 219  *
 220  * Recovery is done in three passes.  In the first pass, we look for the
 221  * end of the log.  In the second, we assemble the list of revoke
 222  * blocks.  In the third and final pass, we replay any un-revoked blocks
 223  * in the log.
 224  */
 225 int journal_recover(journal_t *journal)
 226 {
 227         int                     err;
 228         journal_superblock_t *  sb;
 229
 230         struct recovery_info    info;
 231
 232         memset(&info, 0, sizeof(info));
 233         sb = journal->j_superblock;
 234
 235         /*
 236          * The journal superblock's s_start field (the current log head)
 237          * is always zero if, and only if, the journal was cleanly
 238          * unmounted.
 239          */
 240
 241         if (!sb->s_start) {
 242                 jbd_debug(1, "No recovery required, last transaction %d\n",
 243                           be32_to_cpu(sb->s_sequence));
 244                 journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1;
 245                 return 0;
 246         }
 247
 248         err = do_one_pass(journal, &info, PASS_SCAN);
 249         if (!err)
 250                 err = do_one_pass(journal, &info, PASS_REVOKE);
 251         if (!err)
 252                 err = do_one_pass(journal, &info, PASS_REPLAY);
 253
 254         jbd_debug(1, "JBD: recovery, exit status %d, "
 255                   "recovered transactions %u to %u\n",
 256                   err, info.start_transaction, info.end_transaction);
 257         jbd_debug(1, "JBD: Replayed %d and revoked %d/%d blocks\n",
 258                   info.nr_replays, info.nr_revoke_hits, info.nr_revokes);
 259
 260         /* Restart the log at the next transaction ID, thus invalidating
 261          * any existing commit records in the log. */
 262         journal->j_transaction_sequence = ++info.end_transaction;
 263
 264         journal_clear_revoke(journal);
 265         sync_blockdev(journal->j_fs_dev);
 266         return err;
 267 }
 268
 269 /**
 270  * journal_skip_recovery - Start journal and wipe exiting records
 271  * @journal: journal to startup
 272  *
 273  * Locate any valid recovery information from the journal and set up the
 274  * journal structures in memory to ignore it (presumably because the
 275  * caller has evidence that it is out of date).
 276  * This function does'nt appear to be exorted..
 277  *
 278  * We perform one pass over the journal to allow us to tell the user how
 279  * much recovery information is being erased, and to let us initialise
 280  * the journal transaction sequence numbers to the next unused ID.
 281  */
 282 int journal_skip_recovery(journal_t *journal)
 283 {
 284         int                     err;
 285         struct recovery_info    info;
 286
 287         memset (&info, 0, sizeof(info));
 288
 289         err = do_one_pass(journal, &info, PASS_SCAN);
 290
 291         if (err) {
 292                 printk(KERN_ERR "JBD: error %d scanning journal\n", err);
 293                 ++journal->j_transaction_sequence;
 294         } else {
 295 #ifdef CONFIG_JBD_DEBUG
 296                 journal_superblock_t *sb = journal->j_superblock;
 297
 298                 int dropped = info.end_transaction - be32_to_cpu(sb->s_sequence);
 299 #endif
 300                 jbd_debug(1,
 301                           "JBD: ignoring %d transaction%s from the journal.\n",
 302                           dropped, (dropped == 1) ? "" : "s");
 303                 journal->j_transaction_sequence = ++info.end_transaction;
 304         }
 305
 306         journal->j_tail = 0;
 307         return err;
 308 }
 309
 310 static inline unsigned long long read_tag_block(int tag_bytes, journal_block_tag_t *tag)
 311 {
 312         unsigned long long block = be32_to_cpu(tag->t_blocknr);
 313         if (tag_bytes > JBD_TAG_SIZE32)
 314                 block |= (__u64)be32_to_cpu(tag->t_blocknr_high) << 32;
 315         return block;
 316 }
 317
 318 /*
 319  * calc_chksums calculates the checksums for the blocks described in the
 320  * descriptor block.
 321  */
 322 static int calc_chksums(journal_t *journal, struct buffer_head *bh,
 323                         unsigned long long *next_log_block, __u32 *crc32_sum)
 324 {
 325         int i, num_blks, err;
 326         unsigned long long io_block;
 327         struct buffer_head *obh;
 328
 329         num_blks = count_tags(journal, bh);
 330         /* Calculate checksum of the descriptor block. */
 331         *crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size);
 332
 333         for (i = 0; i < num_blks; i++) {
 334                 io_block = (*next_log_block)++;
 335                 wrap(journal, *next_log_block);
 336                 err = jread(&obh, journal, io_block);
 337                 if (err) {
 338                         printk(KERN_ERR "JBD: IO error %d recovering block "
 339                                 "%llu in log\n", err, io_block);
 340                         return 1;
 341                 } else {
 342                         *crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data,
 343                                      obh->b_size);
 344                 }
 345                 brelse(obh);
 346         }
 347         return 0;
 348 }
 349
 350 static int do_one_pass(journal_t *journal,
 351                         struct recovery_info *info, enum passtype pass)
 352 {
 353         unsigned int            first_commit_ID, next_commit_ID;
 354         unsigned long long      next_log_block;
 355         int                     err, success = 0;
 356         journal_superblock_t *  sb;
 357         journal_header_t *      tmp;
 358         struct buffer_head *    bh;
 359         unsigned int            sequence;
 360         int                     blocktype;
 361         int                     tag_bytes = journal_tag_bytes(journal);
 362         __u32                   crc32_sum = ~0; /* Transactional Checksums */
 363
 364         /*
 365          * First thing is to establish what we expect to find in the log
 366          * (in terms of transaction IDs), and where (in terms of log
 367          * block offsets): query the superblock.
 368          */
 369
 370         sb = journal->j_superblock;
 371         next_commit_ID = be32_to_cpu(sb->s_sequence);
 372         next_log_block = be32_to_cpu(sb->s_start);
 373
 374         first_commit_ID = next_commit_ID;
 375         if (pass == PASS_SCAN)
 376                 info->start_transaction = first_commit_ID;
 377
 378         jbd_debug(1, "Starting recovery pass %d\n", pass);
 379
 380         /*
 381          * Now we walk through the log, transaction by transaction,
 382          * making sure that each transaction has a commit block in the
 383          * expected place.  Each complete transaction gets replayed back
 384          * into the main filesystem.
 385          */
 386
 387         while (1) {
 388                 int                     flags;
 389                 char *                  tagp;
 390                 journal_block_tag_t *   tag;
 391                 struct buffer_head *    obh;
 392                 struct buffer_head *    nbh;
 393
 394                 cond_resched();
 395
 396                 /* If we already know where to stop the log traversal,
 397                  * check right now that we haven't gone past the end of
 398                  * the log. */
 399
 400                 if (pass != PASS_SCAN)
 401                         if (tid_geq(next_commit_ID, info->end_transaction))
 402                                 break;
 403
 404                 jbd_debug(2, "Scanning for sequence ID %u at %llu/%lu\n",
 405                           next_commit_ID, next_log_block, journal->j_last);
 406
 407                 /* Skip over each chunk of the transaction looking
 408                  * either the next descriptor block or the final commit
 409                  * record. */
 410
 411                 jbd_debug(3, "JBD: checking block %llu\n", next_log_block);
 412                 err = jread(&bh, journal, next_log_block);
 413                 if (err)
 414                         goto failed;
 415
 416                 next_log_block++;
 417                 wrap(journal, next_log_block);
 418
 419                 /* What kind of buffer is it?
 420                  *
 421                  * If it is a descriptor block, check that it has the
 422                  * expected sequence number.  Otherwise, we're all done
 423                  * here. */
 424
 425                 tmp = (journal_header_t *)bh->b_data;
 426
 427                 if (tmp->h_magic != cpu_to_be32(JFS_MAGIC_NUMBER)) {
 428                         brelse(bh);
 429                         break;
 430                 }
 431
 432                 blocktype = be32_to_cpu(tmp->h_blocktype);
 433                 sequence = be32_to_cpu(tmp->h_sequence);
 434                 jbd_debug(3, "Found magic %d, sequence %d\n",
 435                           blocktype, sequence);
 436
 437                 if (sequence != next_commit_ID) {
 438                         brelse(bh);
 439                         break;
 440                 }
 441
 442                 /* OK, we have a valid descriptor block which matches
 443                  * all of the sequence number checks.  What are we going
 444                  * to do with it?  That depends on the pass... */
 445
 446                 switch(blocktype) {
 447                 case JFS_DESCRIPTOR_BLOCK:
 448                         /* If it is a valid descriptor block, replay it
 449                          * in pass REPLAY; if journal_checksums enabled, then
 450                          * calculate checksums in PASS_SCAN, otherwise,
 451                          * just skip over the blocks it describes. */
 452                         if (pass != PASS_REPLAY) {
 453                                 if (pass == PASS_SCAN &&
 454                                     JFS_HAS_COMPAT_FEATURE(journal,
 455                                             JFS_FEATURE_COMPAT_CHECKSUM) &&
 456                                     !info->end_transaction) {
 457                                         if (calc_chksums(journal, bh,
 458                                                         &next_log_block,
 459                                                         &crc32_sum)) {
 460                                                 brelse(bh);
 461                                                 break;
 462                                         }
 463                                         brelse(bh);
 464                                         continue;
 465                                 }
 466                                 next_log_block += count_tags(journal, bh);
 467                                 wrap(journal, next_log_block);
 468                                 brelse(bh);
 469                                 continue;
 470                         }
 471
 472                         /* A descriptor block: we can now write all of
 473                          * the data blocks.  Yay, useful work is finally
 474                          * getting done here! */
 475
 476                         tagp = &bh->b_data[sizeof(journal_header_t)];
 477                         while ((tagp - bh->b_data + tag_bytes)
 478                                <= journal->j_blocksize) {
 479                                 unsigned long long io_block;
 480
 481                                 tag = (journal_block_tag_t *) tagp;
 482                                 flags = be32_to_cpu(tag->t_flags);
 483
 484                                 io_block = next_log_block++;
 485                                 wrap(journal, next_log_block);
 486                                 err = jread(&obh, journal, io_block);
 487                                 if (err) {
 488                                         /* Recover what we can, but
 489                                          * report failure at the end. */
 490                                         success = err;
 491                                         printk (KERN_ERR
 492                                                 "JBD: IO error %d recovering "
 493                                                 "block %llu in log\n",
 494                                                 err, io_block);
 495                                 } else {
 496                                         unsigned long long blocknr;
 497
 498                                         J_ASSERT(obh != NULL);
 499                                         blocknr = read_tag_block(tag_bytes,
 500                                                                  tag);
 501
 502                                         /* If the block has been
 503                                          * revoked, then we're all done
 504                                          * here. */
 505                                         if (journal_test_revoke
 506                                             (journal, blocknr,
 507                                              next_commit_ID)) {
 508                                                 brelse(obh);
 509                                                 ++info->nr_revoke_hits;
 510                                                 goto skip_write;
 511                                         }
 512
 513                                         /* Find a buffer for the new
 514                                          * data being restored */
 515                                         nbh = __getblk(journal->j_fs_dev,
 516                                                         blocknr,
 517                                                         journal->j_blocksize);
 518                                         if (nbh == NULL) {
 519                                                 printk(KERN_ERR
 520                                                        "JBD: Out of memory "
 521                                                        "during recovery.\n");
 522                                                 err = -ENOMEM;
 523                                                 brelse(bh);
 524                                                 brelse(obh);
 525                                                 goto failed;
 526                                         }
 527
 528                                         lock_buffer(nbh);
 529                                         memcpy(nbh->b_data, obh->b_data,
 530                                                         journal->j_blocksize);
 531                                         if (flags & JFS_FLAG_ESCAPE) {
 532                                                 journal_header_t *header;
 533
 534                                                 header = (journal_header_t *) &nbh->b_data[0];
 535                                                 header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER);
 536                                         }
 537
 538                                         BUFFER_TRACE(nbh, "marking dirty");
 539                                         set_buffer_uptodate(nbh);
 540                                         mark_buffer_dirty(nbh);
 541                                         BUFFER_TRACE(nbh, "marking uptodate");
 542                                         ++info->nr_replays;
 543                                         /* ll_rw_block(WRITE, 1, &nbh); */
 544                                         unlock_buffer(nbh);
 545                                         brelse(obh);
 546                                         brelse(nbh);
 547                                 }
 548
 549                         skip_write:
 550                                 tagp += tag_bytes;
 551                                 if (!(flags & JFS_FLAG_SAME_UUID))
 552                                         tagp += 16;
 553
 554                                 if (flags & JFS_FLAG_LAST_TAG)
 555                                         break;
 556                         }
 557
 558                         brelse(bh);
 559                         continue;
 560
 561                 case JFS_COMMIT_BLOCK:
 562                         jbd_debug(3, "Commit block for #%u found\n",
 563                                   next_commit_ID);
 564                         /*     How to differentiate between interrupted commit
 565                          *               and journal corruption ?
 566                          *
 567                          * {nth transaction}
 568                          *        Checksum Verification Failed
 569                          *                       |
 570                          *               ____________________
 571                          *              |                    |
 572                          *      async_commit             sync_commit
 573                          *              |                    |
 574                          *              | GO TO NEXT    "Journal Corruption"
 575                          *              | TRANSACTION
 576                          *              |
 577                          * {(n+1)th transanction}
 578                          *              |
 579                          *       _______|______________
 580                          *      |                     |
 581                          * Commit block found   Commit block not found
 582                          *      |                     |
 583                          * "Journal Corruption"       |
 584                          *               _____________|_________
 585                          *              |                       |
 586                          *      nth trans corrupt       OR   nth trans
 587                          *      and (n+1)th interrupted     interrupted
 588                          *      before commit block
 589                          *      could reach the disk.
 590                          *      (Cannot find the difference in above
 591                          *       mentioned conditions. Hence assume
 592                          *       "Interrupted Commit".)
 593                          */
 594
 595                         /* Found an expected commit block: if checksums
 596                          * are present verify them in PASS_SCAN; else not
 597                          * much to do other than move on to the next sequence
 598                          * number. */
 599                         if (pass == PASS_SCAN &&
 600                             JFS_HAS_COMPAT_FEATURE(journal,
 601                                     JFS_FEATURE_COMPAT_CHECKSUM)) {
 602                                 int chksum_err, chksum_seen;
 603                                 struct commit_header *cbh =
 604                                         (struct commit_header *)bh->b_data;
 605                                 unsigned found_chksum =
 606                                         be32_to_cpu(cbh->h_chksum[0]);
 607
 608                                 chksum_err = chksum_seen = 0;
 609
 610                                 jbd_debug(3, "Checksums %x %x\n",
 611                                           crc32_sum, found_chksum);
 612                                 if (info->end_transaction) {
 613                                         journal->j_failed_commit =
 614                                                 info->end_transaction;
 615                                         brelse(bh);
 616                                         break;
 617                                 }
 618
 619                                 if (crc32_sum == found_chksum &&
 620                                     cbh->h_chksum_type == JBD2_CRC32_CHKSUM &&
 621                                     cbh->h_chksum_size ==
 622                                                 JBD2_CRC32_CHKSUM_SIZE)
 623                                        chksum_seen = 1;
 624                                 else if (!(cbh->h_chksum_type == 0 &&
 625                                              cbh->h_chksum_size == 0 &&
 626                                              found_chksum == 0 &&
 627                                              !chksum_seen))
 628                                 /*
 629                                  * If fs is mounted using an old kernel and then
 630                                  * kernel with journal_chksum is used then we
 631                                  * get a situation where the journal flag has
 632                                  * checksum flag set but checksums are not
 633                                  * present i.e chksum = 0, in the individual
 634                                  * commit blocks.
 635                                  * Hence to avoid checksum failures, in this
 636                                  * situation, this extra check is added.
 637                                  */
 638                                                 chksum_err = 1;
 639
 640                                 if (chksum_err) {
 641                                         info->end_transaction = next_commit_ID;
 642                                         jbd_debug(1, "Checksum_err %x %x\n",
 643                                                   crc32_sum, found_chksum);
 644                                         if (!JFS_HAS_INCOMPAT_FEATURE(journal,
 645                                            JFS_FEATURE_INCOMPAT_ASYNC_COMMIT)){
 646                                                 journal->j_failed_commit =
 647                                                         next_commit_ID;
 648                                                 brelse(bh);
 649                                                 break;
 650                                         }
 651                                 }
 652                                 crc32_sum = ~0;
 653                         }
 654                         brelse(bh);
 655                         next_commit_ID++;
 656                         continue;
 657
 658                 case JFS_REVOKE_BLOCK:
 659                         /* If we aren't in the REVOKE pass, then we can
 660                          * just skip over this block. */
 661                         if (pass != PASS_REVOKE) {
 662                                 brelse(bh);
 663                                 continue;
 664                         }
 665
 666                         err = scan_revoke_records(journal, bh,
 667                                                   next_commit_ID, info);
 668                         brelse(bh);
 669                         if (err)
 670                                 goto failed;
 671                         continue;
 672
 673                 default:
 674                         jbd_debug(3, "Unrecognised magic %d, end of scan.\n",
 675                                   blocktype);
 676                         brelse(bh);
 677                         goto done;
 678                 }
 679         }
 680
 681  done:
 682         /*
 683          * We broke out of the log scan loop: either we came to the
 684          * known end of the log or we found an unexpected block in the
 685          * log.  If the latter happened, then we know that the "current"
 686          * transaction marks the end of the valid log.
 687          */
 688
 689         if (pass == PASS_SCAN) {
 690                 if (!info->end_transaction)
 691                         info->end_transaction = next_commit_ID;
 692         } else {
 693                 /* It's really bad news if different passes end up at
 694                  * different places (but possible due to IO errors). */
 695                 if (info->end_transaction != next_commit_ID) {
 696                         printk (KERN_ERR "JBD: recovery pass %d ended at "
 697                                 "transaction %u, expected %u\n",
 698                                 pass, next_commit_ID, info->end_transaction);
 699                         if (!success)
 700                                 success = -EIO;
 701                 }
 702         }
 703
 704         return success;
 705
 706  failed:
 707         return err;
 708 }
 709
 710
 711 /* Scan a revoke record, marking all blocks mentioned as revoked. */
 712
 713 static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
 714                                tid_t sequence, struct recovery_info *info)
 715 {
 716         journal_revoke_header_t *header;
 717         int offset, max;
 718         int record_len = 4;
 719
 720         header = (journal_revoke_header_t *) bh->b_data;
 721         offset = sizeof(journal_revoke_header_t);
 722         max = be32_to_cpu(header->r_count);
 723
 724         if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_64BIT))
 725                 record_len = 8;
 726
 727         while (offset < max) {
 728                 unsigned long long blocknr;
 729                 int err;
 730
 731                 if (record_len == 4) {
 732                         __be32 b;
 733                         memcpy(&b, bh->b_data + offset, sizeof(__be32));
 734                         blocknr = ext2fs_be32_to_cpu(b);
 735                 } else {
 736                         __be64 b;
 737                         memcpy(&b, bh->b_data + offset, sizeof(__be64));
 738                         blocknr = ext2fs_be64_to_cpu(b);
 739                 }
 740
 741                 offset += record_len;
 742                 err = journal_set_revoke(journal, blocknr, sequence);
 743                 if (err)
 744                         return err;
 745                 ++info->nr_revokes;
 746         }
 747         return 0;
 748 }