1 /* 2 * linux/fs/jbd2/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/jbd2.h> 22 #include <linux/errno.h> 23 #include <linux/crc32.h> 24 #include <linux/blkdev.h> 25 #endif 26 27 /* 28 * Maintain information about the progress of the recovery job, so that 29 * the different passes can carry information between them. 30 */ 31 struct recovery_info 32 { 33 tid_t start_transaction; 34 tid_t end_transaction; 35 36 int nr_replays; 37 int nr_revokes; 38 int nr_revoke_hits; 39 }; 40 41 enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY}; 42 static int do_one_pass(journal_t *journal, 43 struct recovery_info *info, enum passtype pass); 44 static int scan_revoke_records(journal_t *, struct buffer_head *, 45 tid_t, struct recovery_info *); 46 47 #ifdef __KERNEL__ 48 49 /* Release readahead buffers after use */ 50 static void journal_brelse_array(struct buffer_head *b[], int n) 51 { 52 while (--n >= 0) 53 brelse (b[n]); 54 } 55 56 57 /* 58 * When reading from the journal, we are going through the block device 59 * layer directly and so there is no readahead being done for us. We 60 * need to implement any readahead ourselves if we want it to happen at 61 * all. Recovery is basically one long sequential read, so make sure we 62 * do the IO in reasonably large chunks. 63 * 64 * This is not so critical that we need to be enormously clever about 65 * the readahead size, though. 128K is a purely arbitrary, good-enough 66 * fixed value. 67 */ 68 69 #define MAXBUF 8 70 static int do_readahead(journal_t *journal, unsigned int start) 71 { 72 int err; 73 unsigned int max, nbufs, next; 74 unsigned long long blocknr; 75 struct buffer_head *bh; 76 77 struct buffer_head * bufs[MAXBUF]; 78 79 /* Do up to 128K of readahead */ 80 max = start + (128 * 1024 / journal->j_blocksize); 81 if (max > journal->j_maxlen) 82 max = journal->j_maxlen; 83 84 /* Do the readahead itself. We'll submit MAXBUF buffer_heads at 85 * a time to the block device IO layer. */ 86 87 nbufs = 0; 88 89 for (next = start; next < max; next++) { 90 err = jbd2_journal_bmap(journal, next, &blocknr); 91 92 if (err) { 93 printk(KERN_ERR "JBD2: bad block at offset %u\n", 94 next); 95 goto failed; 96 } 97 98 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); 99 if (!bh) { 100 err = -ENOMEM; 101 goto failed; 102 } 103 104 if (!buffer_uptodate(bh) && !buffer_locked(bh)) { 105 bufs[nbufs++] = bh; 106 if (nbufs == MAXBUF) { 107 ll_rw_block(REQ_OP_READ, 0, nbufs, bufs); 108 journal_brelse_array(bufs, nbufs); 109 nbufs = 0; 110 } 111 } else 112 brelse(bh); 113 } 114 115 if (nbufs) 116 ll_rw_block(REQ_OP_READ, 0, nbufs, bufs); 117 err = 0; 118 119 failed: 120 if (nbufs) 121 journal_brelse_array(bufs, nbufs); 122 return err; 123 } 124 125 #endif /* __KERNEL__ */ 126 127 128 /* 129 * Read a block from the journal 130 */ 131 132 static int jread(struct buffer_head **bhp, journal_t *journal, 133 unsigned int offset) 134 { 135 int err; 136 unsigned long long blocknr; 137 struct buffer_head *bh; 138 139 *bhp = NULL; 140 141 if (offset >= journal->j_maxlen) { 142 printk(KERN_ERR "JBD2: corrupted journal superblock\n"); 143 return -EFSCORRUPTED; 144 } 145 146 err = jbd2_journal_bmap(journal, offset, &blocknr); 147 148 if (err) { 149 printk(KERN_ERR "JBD2: bad block at offset %u\n", 150 offset); 151 return err; 152 } 153 154 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); 155 if (!bh) 156 return -ENOMEM; 157 158 if (!buffer_uptodate(bh)) { 159 /* If this is a brand new buffer, start readahead. 160 Otherwise, we assume we are already reading it. */ 161 if (!buffer_req(bh)) 162 do_readahead(journal, offset); 163 wait_on_buffer(bh); 164 } 165 166 if (!buffer_uptodate(bh)) { 167 printk(KERN_ERR "JBD2: Failed to read block at offset %u\n", 168 offset); 169 brelse(bh); 170 return -EIO; 171 } 172 173 *bhp = bh; 174 return 0; 175 } 176 177 static int jbd2_descriptor_block_csum_verify(journal_t *j, void *buf) 178 { 179 struct jbd2_journal_block_tail *tail; 180 __be32 provided; 181 __u32 calculated; 182 183 if (!jbd2_journal_has_csum_v2or3(j)) 184 return 1; 185 186 tail = (struct jbd2_journal_block_tail *)(buf + j->j_blocksize - 187 sizeof(struct jbd2_journal_block_tail)); 188 provided = tail->t_checksum; 189 tail->t_checksum = 0; 190 calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize); 191 tail->t_checksum = provided; 192 193 return provided == cpu_to_be32(calculated); 194 } 195 196 /* 197 * Count the number of in-use tags in a journal descriptor block. 198 */ 199 200 static int count_tags(journal_t *journal, struct buffer_head *bh) 201 { 202 char * tagp; 203 journal_block_tag_t * tag; 204 int nr = 0, size = journal->j_blocksize; 205 int tag_bytes = journal_tag_bytes(journal); 206 207 if (jbd2_journal_has_csum_v2or3(journal)) 208 size -= sizeof(struct jbd2_journal_block_tail); 209 210 tagp = &bh->b_data[sizeof(journal_header_t)]; 211 212 while ((tagp - bh->b_data + tag_bytes) <= size) { 213 tag = (journal_block_tag_t *) tagp; 214 215 nr++; 216 tagp += tag_bytes; 217 if (!(tag->t_flags & cpu_to_be16(JBD2_FLAG_SAME_UUID))) 218 tagp += 16; 219 220 if (tag->t_flags & cpu_to_be16(JBD2_FLAG_LAST_TAG)) 221 break; 222 } 223 224 return nr; 225 } 226 227 228 /* Make sure we wrap around the log correctly! */ 229 #define wrap(journal, var) \ 230 do { \ 231 if (var >= (journal)->j_last) \ 232 var -= ((journal)->j_last - (journal)->j_first); \ 233 } while (0) 234 235 /** 236 * jbd2_journal_recover - recovers a on-disk journal 237 * @journal: the journal to recover 238 * 239 * The primary function for recovering the log contents when mounting a 240 * journaled device. 241 * 242 * Recovery is done in three passes. In the first pass, we look for the 243 * end of the log. In the second, we assemble the list of revoke 244 * blocks. In the third and final pass, we replay any un-revoked blocks 245 * in the log. 246 */ 247 int jbd2_journal_recover(journal_t *journal) 248 { 249 int err, err2; 250 journal_superblock_t * sb; 251 252 struct recovery_info info; 253 254 memset(&info, 0, sizeof(info)); 255 sb = journal->j_superblock; 256 257 /* 258 * The journal superblock's s_start field (the current log head) 259 * is always zero if, and only if, the journal was cleanly 260 * unmounted. 261 */ 262 263 if (!sb->s_start) { 264 jbd_debug(1, "No recovery required, last transaction %d\n", 265 be32_to_cpu(sb->s_sequence)); 266 journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1; 267 return 0; 268 } 269 270 err = do_one_pass(journal, &info, PASS_SCAN); 271 if (!err) 272 err = do_one_pass(journal, &info, PASS_REVOKE); 273 if (!err) 274 err = do_one_pass(journal, &info, PASS_REPLAY); 275 276 jbd_debug(1, "JBD2: recovery, exit status %d, " 277 "recovered transactions %u to %u\n", 278 err, info.start_transaction, info.end_transaction); 279 jbd_debug(1, "JBD2: Replayed %d and revoked %d/%d blocks\n", 280 info.nr_replays, info.nr_revoke_hits, info.nr_revokes); 281 282 /* Restart the log at the next transaction ID, thus invalidating 283 * any existing commit records in the log. */ 284 journal->j_transaction_sequence = ++info.end_transaction; 285 286 jbd2_journal_clear_revoke(journal); 287 err2 = sync_blockdev(journal->j_fs_dev); 288 if (!err) 289 err = err2; 290 /* Make sure all replayed data is on permanent storage */ 291 if (journal->j_flags & JBD2_BARRIER) { 292 err2 = blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL); 293 if (!err) 294 err = err2; 295 } 296 return err; 297 } 298 299 /** 300 * jbd2_journal_skip_recovery - Start journal and wipe exiting records 301 * @journal: journal to startup 302 * 303 * Locate any valid recovery information from the journal and set up the 304 * journal structures in memory to ignore it (presumably because the 305 * caller has evidence that it is out of date). 306 * This function doesn't appear to be exported.. 307 * 308 * We perform one pass over the journal to allow us to tell the user how 309 * much recovery information is being erased, and to let us initialise 310 * the journal transaction sequence numbers to the next unused ID. 311 */ 312 int jbd2_journal_skip_recovery(journal_t *journal) 313 { 314 int err; 315 316 struct recovery_info info; 317 318 memset (&info, 0, sizeof(info)); 319 320 err = do_one_pass(journal, &info, PASS_SCAN); 321 322 if (err) { 323 printk(KERN_ERR "JBD2: error %d scanning journal\n", err); 324 ++journal->j_transaction_sequence; 325 } else { 326 #ifdef CONFIG_JBD2_DEBUG 327 int dropped = info.end_transaction - 328 be32_to_cpu(journal->j_superblock->s_sequence); 329 jbd_debug(1, 330 "JBD2: ignoring %d transaction%s from the journal.\n", 331 dropped, (dropped == 1) ? "" : "s"); 332 #endif 333 journal->j_transaction_sequence = ++info.end_transaction; 334 } 335 336 journal->j_tail = 0; 337 return err; 338 } 339 340 static inline unsigned long long read_tag_block(journal_t *journal, 341 journal_block_tag_t *tag) 342 { 343 unsigned long long block = be32_to_cpu(tag->t_blocknr); 344 if (jbd2_has_feature_64bit(journal)) 345 block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32; 346 return block; 347 } 348 349 /* 350 * calc_chksums calculates the checksums for the blocks described in the 351 * descriptor block. 352 */ 353 static int calc_chksums(journal_t *journal, struct buffer_head *bh, 354 unsigned long *next_log_block, __u32 *crc32_sum) 355 { 356 int i, num_blks, err; 357 unsigned long io_block; 358 struct buffer_head *obh; 359 360 num_blks = count_tags(journal, bh); 361 /* Calculate checksum of the descriptor block. */ 362 *crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size); 363 364 for (i = 0; i < num_blks; i++) { 365 io_block = (*next_log_block)++; 366 wrap(journal, *next_log_block); 367 err = jread(&obh, journal, io_block); 368 if (err) { 369 printk(KERN_ERR "JBD2: IO error %d recovering block " 370 "%lu in log\n", err, io_block); 371 return 1; 372 } else { 373 *crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data, 374 obh->b_size); 375 } 376 put_bh(obh); 377 } 378 return 0; 379 } 380 381 static int jbd2_commit_block_csum_verify(journal_t *j, void *buf) 382 { 383 struct commit_header *h; 384 __be32 provided; 385 __u32 calculated; 386 387 if (!jbd2_journal_has_csum_v2or3(j)) 388 return 1; 389 390 h = buf; 391 provided = h->h_chksum[0]; 392 h->h_chksum[0] = 0; 393 calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize); 394 h->h_chksum[0] = provided; 395 396 return provided == cpu_to_be32(calculated); 397 } 398 399 static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag, 400 void *buf, __u32 sequence) 401 { 402 journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag; 403 __u32 csum32; 404 __be32 seq; 405 406 if (!jbd2_journal_has_csum_v2or3(j)) 407 return 1; 408 409 seq = cpu_to_be32(sequence); 410 csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq)); 411 csum32 = jbd2_chksum(j, csum32, buf, j->j_blocksize); 412 413 if (jbd2_has_feature_csum3(j)) 414 return tag3->t_checksum == cpu_to_be32(csum32); 415 else 416 return tag->t_checksum == cpu_to_be16(csum32); 417 } 418 419 static int do_one_pass(journal_t *journal, 420 struct recovery_info *info, enum passtype pass) 421 { 422 unsigned int first_commit_ID, next_commit_ID; 423 unsigned long next_log_block; 424 int err, success = 0; 425 journal_superblock_t * sb; 426 journal_header_t * tmp; 427 struct buffer_head * bh; 428 unsigned int sequence; 429 int blocktype; 430 int tag_bytes = journal_tag_bytes(journal); 431 __u32 crc32_sum = ~0; /* Transactional Checksums */ 432 int descr_csum_size = 0; 433 int block_error = 0; 434 435 /* 436 * First thing is to establish what we expect to find in the log 437 * (in terms of transaction IDs), and where (in terms of log 438 * block offsets): query the superblock. 439 */ 440 441 sb = journal->j_superblock; 442 next_commit_ID = be32_to_cpu(sb->s_sequence); 443 next_log_block = be32_to_cpu(sb->s_start); 444 445 first_commit_ID = next_commit_ID; 446 if (pass == PASS_SCAN) 447 info->start_transaction = first_commit_ID; 448 449 jbd_debug(1, "Starting recovery pass %d\n", pass); 450 451 /* 452 * Now we walk through the log, transaction by transaction, 453 * making sure that each transaction has a commit block in the 454 * expected place. Each complete transaction gets replayed back 455 * into the main filesystem. 456 */ 457 458 while (1) { 459 int flags; 460 char * tagp; 461 journal_block_tag_t * tag; 462 struct buffer_head * obh; 463 struct buffer_head * nbh; 464 465 cond_resched(); 466 467 /* If we already know where to stop the log traversal, 468 * check right now that we haven't gone past the end of 469 * the log. */ 470 471 if (pass != PASS_SCAN) 472 if (tid_geq(next_commit_ID, info->end_transaction)) 473 break; 474 475 jbd_debug(2, "Scanning for sequence ID %u at %lu/%lu\n", 476 next_commit_ID, next_log_block, journal->j_last); 477 478 /* Skip over each chunk of the transaction looking 479 * either the next descriptor block or the final commit 480 * record. */ 481 482 jbd_debug(3, "JBD2: checking block %ld\n", next_log_block); 483 err = jread(&bh, journal, next_log_block); 484 if (err) 485 goto failed; 486 487 next_log_block++; 488 wrap(journal, next_log_block); 489 490 /* What kind of buffer is it? 491 * 492 * If it is a descriptor block, check that it has the 493 * expected sequence number. Otherwise, we're all done 494 * here. */ 495 496 tmp = (journal_header_t *)bh->b_data; 497 498 if (tmp->h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER)) { 499 brelse(bh); 500 break; 501 } 502 503 blocktype = be32_to_cpu(tmp->h_blocktype); 504 sequence = be32_to_cpu(tmp->h_sequence); 505 jbd_debug(3, "Found magic %d, sequence %d\n", 506 blocktype, sequence); 507 508 if (sequence != next_commit_ID) { 509 brelse(bh); 510 break; 511 } 512 513 /* OK, we have a valid descriptor block which matches 514 * all of the sequence number checks. What are we going 515 * to do with it? That depends on the pass... */ 516 517 switch(blocktype) { 518 case JBD2_DESCRIPTOR_BLOCK: 519 /* Verify checksum first */ 520 if (jbd2_journal_has_csum_v2or3(journal)) 521 descr_csum_size = 522 sizeof(struct jbd2_journal_block_tail); 523 if (descr_csum_size > 0 && 524 !jbd2_descriptor_block_csum_verify(journal, 525 bh->b_data)) { 526 printk(KERN_ERR "JBD2: Invalid checksum " 527 "recovering block %lu in log\n", 528 next_log_block); 529 err = -EFSBADCRC; 530 brelse(bh); 531 goto failed; 532 } 533 534 /* If it is a valid descriptor block, replay it 535 * in pass REPLAY; if journal_checksums enabled, then 536 * calculate checksums in PASS_SCAN, otherwise, 537 * just skip over the blocks it describes. */ 538 if (pass != PASS_REPLAY) { 539 if (pass == PASS_SCAN && 540 jbd2_has_feature_checksum(journal) && 541 !info->end_transaction) { 542 if (calc_chksums(journal, bh, 543 &next_log_block, 544 &crc32_sum)) { 545 put_bh(bh); 546 break; 547 } 548 put_bh(bh); 549 continue; 550 } 551 next_log_block += count_tags(journal, bh); 552 wrap(journal, next_log_block); 553 put_bh(bh); 554 continue; 555 } 556 557 /* A descriptor block: we can now write all of 558 * the data blocks. Yay, useful work is finally 559 * getting done here! */ 560 561 tagp = &bh->b_data[sizeof(journal_header_t)]; 562 while ((tagp - bh->b_data + tag_bytes) 563 <= journal->j_blocksize - descr_csum_size) { 564 unsigned long io_block; 565 566 tag = (journal_block_tag_t *) tagp; 567 flags = be16_to_cpu(tag->t_flags); 568 569 io_block = next_log_block++; 570 wrap(journal, next_log_block); 571 err = jread(&obh, journal, io_block); 572 if (err) { 573 /* Recover what we can, but 574 * report failure at the end. */ 575 success = err; 576 printk(KERN_ERR 577 "JBD2: IO error %d recovering " 578 "block %ld in log\n", 579 err, io_block); 580 } else { 581 unsigned long long blocknr; 582 583 J_ASSERT(obh != NULL); 584 blocknr = read_tag_block(journal, 585 tag); 586 587 /* If the block has been 588 * revoked, then we're all done 589 * here. */ 590 if (jbd2_journal_test_revoke 591 (journal, blocknr, 592 next_commit_ID)) { 593 brelse(obh); 594 ++info->nr_revoke_hits; 595 goto skip_write; 596 } 597 598 /* Look for block corruption */ 599 if (!jbd2_block_tag_csum_verify( 600 journal, tag, obh->b_data, 601 be32_to_cpu(tmp->h_sequence))) { 602 brelse(obh); 603 success = -EFSBADCRC; 604 printk(KERN_ERR "JBD2: Invalid " 605 "checksum recovering " 606 "block %llu in log\n", 607 blocknr); 608 block_error = 1; 609 goto skip_write; 610 } 611 612 /* Find a buffer for the new 613 * data being restored */ 614 nbh = __getblk(journal->j_fs_dev, 615 blocknr, 616 journal->j_blocksize); 617 if (nbh == NULL) { 618 printk(KERN_ERR 619 "JBD2: Out of memory " 620 "during recovery.\n"); 621 err = -ENOMEM; 622 brelse(bh); 623 brelse(obh); 624 goto failed; 625 } 626 627 lock_buffer(nbh); 628 memcpy(nbh->b_data, obh->b_data, 629 journal->j_blocksize); 630 if (flags & JBD2_FLAG_ESCAPE) { 631 *((__be32 *)nbh->b_data) = 632 cpu_to_be32(JBD2_MAGIC_NUMBER); 633 } 634 635 BUFFER_TRACE(nbh, "marking dirty"); 636 set_buffer_uptodate(nbh); 637 mark_buffer_dirty(nbh); 638 BUFFER_TRACE(nbh, "marking uptodate"); 639 ++info->nr_replays; 640 /* ll_rw_block(WRITE, 1, &nbh); */ 641 unlock_buffer(nbh); 642 brelse(obh); 643 brelse(nbh); 644 } 645 646 skip_write: 647 tagp += tag_bytes; 648 if (!(flags & JBD2_FLAG_SAME_UUID)) 649 tagp += 16; 650 651 if (flags & JBD2_FLAG_LAST_TAG) 652 break; 653 } 654 655 brelse(bh); 656 continue; 657 658 case JBD2_COMMIT_BLOCK: 659 /* How to differentiate between interrupted commit 660 * and journal corruption ? 661 * 662 * {nth transaction} 663 * Checksum Verification Failed 664 * | 665 * ____________________ 666 * | | 667 * async_commit sync_commit 668 * | | 669 * | GO TO NEXT "Journal Corruption" 670 * | TRANSACTION 671 * | 672 * {(n+1)th transanction} 673 * | 674 * _______|______________ 675 * | | 676 * Commit block found Commit block not found 677 * | | 678 * "Journal Corruption" | 679 * _____________|_________ 680 * | | 681 * nth trans corrupt OR nth trans 682 * and (n+1)th interrupted interrupted 683 * before commit block 684 * could reach the disk. 685 * (Cannot find the difference in above 686 * mentioned conditions. Hence assume 687 * "Interrupted Commit".) 688 */ 689 690 /* Found an expected commit block: if checksums 691 * are present verify them in PASS_SCAN; else not 692 * much to do other than move on to the next sequence 693 * number. */ 694 if (pass == PASS_SCAN && 695 jbd2_has_feature_checksum(journal)) { 696 int chksum_err, chksum_seen; 697 struct commit_header *cbh = 698 (struct commit_header *)bh->b_data; 699 unsigned found_chksum = 700 be32_to_cpu(cbh->h_chksum[0]); 701 702 chksum_err = chksum_seen = 0; 703 704 if (info->end_transaction) { 705 journal->j_failed_commit = 706 info->end_transaction; 707 brelse(bh); 708 break; 709 } 710 711 if (crc32_sum == found_chksum && 712 cbh->h_chksum_type == JBD2_CRC32_CHKSUM && 713 cbh->h_chksum_size == 714 JBD2_CRC32_CHKSUM_SIZE) 715 chksum_seen = 1; 716 else if (!(cbh->h_chksum_type == 0 && 717 cbh->h_chksum_size == 0 && 718 found_chksum == 0 && 719 !chksum_seen)) 720 /* 721 * If fs is mounted using an old kernel and then 722 * kernel with journal_chksum is used then we 723 * get a situation where the journal flag has 724 * checksum flag set but checksums are not 725 * present i.e chksum = 0, in the individual 726 * commit blocks. 727 * Hence to avoid checksum failures, in this 728 * situation, this extra check is added. 729 */ 730 chksum_err = 1; 731 732 if (chksum_err) { 733 info->end_transaction = next_commit_ID; 734 735 if (!jbd2_has_feature_async_commit(journal)) { 736 journal->j_failed_commit = 737 next_commit_ID; 738 brelse(bh); 739 break; 740 } 741 } 742 crc32_sum = ~0; 743 } 744 if (pass == PASS_SCAN && 745 !jbd2_commit_block_csum_verify(journal, 746 bh->b_data)) { 747 info->end_transaction = next_commit_ID; 748 749 if (!jbd2_has_feature_async_commit(journal)) { 750 journal->j_failed_commit = 751 next_commit_ID; 752 brelse(bh); 753 break; 754 } 755 } 756 brelse(bh); 757 next_commit_ID++; 758 continue; 759 760 case JBD2_REVOKE_BLOCK: 761 /* If we aren't in the REVOKE pass, then we can 762 * just skip over this block. */ 763 if (pass != PASS_REVOKE) { 764 brelse(bh); 765 continue; 766 } 767 768 err = scan_revoke_records(journal, bh, 769 next_commit_ID, info); 770 brelse(bh); 771 if (err) 772 goto failed; 773 continue; 774 775 default: 776 jbd_debug(3, "Unrecognised magic %d, end of scan.\n", 777 blocktype); 778 brelse(bh); 779 goto done; 780 } 781 } 782 783 done: 784 /* 785 * We broke out of the log scan loop: either we came to the 786 * known end of the log or we found an unexpected block in the 787 * log. If the latter happened, then we know that the "current" 788 * transaction marks the end of the valid log. 789 */ 790 791 if (pass == PASS_SCAN) { 792 if (!info->end_transaction) 793 info->end_transaction = next_commit_ID; 794 } else { 795 /* It's really bad news if different passes end up at 796 * different places (but possible due to IO errors). */ 797 if (info->end_transaction != next_commit_ID) { 798 printk(KERN_ERR "JBD2: recovery pass %d ended at " 799 "transaction %u, expected %u\n", 800 pass, next_commit_ID, info->end_transaction); 801 if (!success) 802 success = -EIO; 803 } 804 } 805 if (block_error && success == 0) 806 success = -EIO; 807 return success; 808 809 failed: 810 return err; 811 } 812 813 /* Scan a revoke record, marking all blocks mentioned as revoked. */ 814 815 static int scan_revoke_records(journal_t *journal, struct buffer_head *bh, 816 tid_t sequence, struct recovery_info *info) 817 { 818 jbd2_journal_revoke_header_t *header; 819 int offset, max; 820 int csum_size = 0; 821 __u32 rcount; 822 int record_len = 4; 823 824 header = (jbd2_journal_revoke_header_t *) bh->b_data; 825 offset = sizeof(jbd2_journal_revoke_header_t); 826 rcount = be32_to_cpu(header->r_count); 827 828 if (!jbd2_descriptor_block_csum_verify(journal, header)) 829 return -EFSBADCRC; 830 831 if (jbd2_journal_has_csum_v2or3(journal)) 832 csum_size = sizeof(struct jbd2_journal_block_tail); 833 if (rcount > journal->j_blocksize - csum_size) 834 return -EINVAL; 835 max = rcount; 836 837 if (jbd2_has_feature_64bit(journal)) 838 record_len = 8; 839 840 while (offset + record_len <= max) { 841 unsigned long long blocknr; 842 int err; 843 844 if (record_len == 4) 845 blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset))); 846 else 847 blocknr = be64_to_cpu(* ((__be64 *) (bh->b_data+offset))); 848 offset += record_len; 849 err = jbd2_journal_set_revoke(journal, blocknr, sequence); 850 if (err) 851 return err; 852 ++info->nr_revokes; 853 } 854 return 0; 855 } 856