1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * linux/fs/jbd2/recovery.c 4 * 5 * Written by Stephen C. Tweedie <sct@redhat.com>, 1999 6 * 7 * Copyright 1999-2000 Red Hat Software --- All Rights Reserved 8 * 9 * Journal recovery routines for the generic filesystem journaling code; 10 * part of the ext2fs journaling system. 11 */ 12 13 #ifndef __KERNEL__ 14 #include "jfs_user.h" 15 #else 16 #include <linux/time.h> 17 #include <linux/fs.h> 18 #include <linux/jbd2.h> 19 #include <linux/errno.h> 20 #include <linux/crc32.h> 21 #include <linux/blkdev.h> 22 #endif 23 24 /* 25 * Maintain information about the progress of the recovery job, so that 26 * the different passes can carry information between them. 27 */ 28 struct recovery_info 29 { 30 tid_t start_transaction; 31 tid_t end_transaction; 32 33 int nr_replays; 34 int nr_revokes; 35 int nr_revoke_hits; 36 }; 37 38 enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY}; 39 static int do_one_pass(journal_t *journal, 40 struct recovery_info *info, enum passtype pass); 41 static int scan_revoke_records(journal_t *, struct buffer_head *, 42 tid_t, struct recovery_info *); 43 44 #ifdef __KERNEL__ 45 46 /* Release readahead buffers after use */ 47 static void journal_brelse_array(struct buffer_head *b[], int n) 48 { 49 while (--n >= 0) 50 brelse (b[n]); 51 } 52 53 54 /* 55 * When reading from the journal, we are going through the block device 56 * layer directly and so there is no readahead being done for us. We 57 * need to implement any readahead ourselves if we want it to happen at 58 * all. Recovery is basically one long sequential read, so make sure we 59 * do the IO in reasonably large chunks. 60 * 61 * This is not so critical that we need to be enormously clever about 62 * the readahead size, though. 128K is a purely arbitrary, good-enough 63 * fixed value. 64 */ 65 66 #define MAXBUF 8 67 static int do_readahead(journal_t *journal, unsigned int start) 68 { 69 int err; 70 unsigned int max, nbufs, next; 71 unsigned long long blocknr; 72 struct buffer_head *bh; 73 74 struct buffer_head * bufs[MAXBUF]; 75 76 /* Do up to 128K of readahead */ 77 max = start + (128 * 1024 / journal->j_blocksize); 78 if (max > journal->j_maxlen) 79 max = journal->j_maxlen; 80 81 /* Do the readahead itself. We'll submit MAXBUF buffer_heads at 82 * a time to the block device IO layer. */ 83 84 nbufs = 0; 85 86 for (next = start; next < max; next++) { 87 err = jbd2_journal_bmap(journal, next, &blocknr); 88 89 if (err) { 90 printk(KERN_ERR "JBD2: bad block at offset %u\n", 91 next); 92 goto failed; 93 } 94 95 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); 96 if (!bh) { 97 err = -ENOMEM; 98 goto failed; 99 } 100 101 if (!buffer_uptodate(bh) && !buffer_locked(bh)) { 102 bufs[nbufs++] = bh; 103 if (nbufs == MAXBUF) { 104 ll_rw_block(REQ_OP_READ, 0, nbufs, bufs); 105 journal_brelse_array(bufs, nbufs); 106 nbufs = 0; 107 } 108 } else 109 brelse(bh); 110 } 111 112 if (nbufs) 113 ll_rw_block(REQ_OP_READ, 0, nbufs, bufs); 114 err = 0; 115 116 failed: 117 if (nbufs) 118 journal_brelse_array(bufs, nbufs); 119 return err; 120 } 121 122 #endif /* __KERNEL__ */ 123 124 125 /* 126 * Read a block from the journal 127 */ 128 129 static int jread(struct buffer_head **bhp, journal_t *journal, 130 unsigned int offset) 131 { 132 int err; 133 unsigned long long blocknr; 134 struct buffer_head *bh; 135 136 *bhp = NULL; 137 138 if (offset >= journal->j_maxlen) { 139 printk(KERN_ERR "JBD2: corrupted journal superblock\n"); 140 return -EFSCORRUPTED; 141 } 142 143 err = jbd2_journal_bmap(journal, offset, &blocknr); 144 145 if (err) { 146 printk(KERN_ERR "JBD2: bad block at offset %u\n", 147 offset); 148 return err; 149 } 150 151 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); 152 if (!bh) 153 return -ENOMEM; 154 155 if (!buffer_uptodate(bh)) { 156 /* If this is a brand new buffer, start readahead. 157 Otherwise, we assume we are already reading it. */ 158 if (!buffer_req(bh)) 159 do_readahead(journal, offset); 160 wait_on_buffer(bh); 161 } 162 163 if (!buffer_uptodate(bh)) { 164 printk(KERN_ERR "JBD2: Failed to read block at offset %u\n", 165 offset); 166 brelse(bh); 167 return -EIO; 168 } 169 170 *bhp = bh; 171 return 0; 172 } 173 174 static int jbd2_descriptor_block_csum_verify(journal_t *j, void *buf) 175 { 176 struct jbd2_journal_block_tail *tail; 177 __be32 provided; 178 __u32 calculated; 179 180 if (!jbd2_journal_has_csum_v2or3(j)) 181 return 1; 182 183 tail = (struct jbd2_journal_block_tail *)(buf + j->j_blocksize - 184 sizeof(struct jbd2_journal_block_tail)); 185 provided = tail->t_checksum; 186 tail->t_checksum = 0; 187 calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize); 188 tail->t_checksum = provided; 189 190 return provided == cpu_to_be32(calculated); 191 } 192 193 /* 194 * Count the number of in-use tags in a journal descriptor block. 195 */ 196 197 static int count_tags(journal_t *journal, struct buffer_head *bh) 198 { 199 char * tagp; 200 journal_block_tag_t * tag; 201 int nr = 0, size = journal->j_blocksize; 202 int tag_bytes = journal_tag_bytes(journal); 203 204 if (jbd2_journal_has_csum_v2or3(journal)) 205 size -= sizeof(struct jbd2_journal_block_tail); 206 207 tagp = &bh->b_data[sizeof(journal_header_t)]; 208 209 while ((tagp - bh->b_data + tag_bytes) <= size) { 210 tag = (journal_block_tag_t *) tagp; 211 212 nr++; 213 tagp += tag_bytes; 214 if (!(tag->t_flags & cpu_to_be16(JBD2_FLAG_SAME_UUID))) 215 tagp += 16; 216 217 if (tag->t_flags & cpu_to_be16(JBD2_FLAG_LAST_TAG)) 218 break; 219 } 220 221 return nr; 222 } 223 224 225 /* Make sure we wrap around the log correctly! */ 226 #define wrap(journal, var) \ 227 do { \ 228 if (var >= (journal)->j_last) \ 229 var -= ((journal)->j_last - (journal)->j_first); \ 230 } while (0) 231 232 /** 233 * jbd2_journal_recover - recovers a on-disk journal 234 * @journal: the journal to recover 235 * 236 * The primary function for recovering the log contents when mounting a 237 * journaled device. 238 * 239 * Recovery is done in three passes. In the first pass, we look for the 240 * end of the log. In the second, we assemble the list of revoke 241 * blocks. In the third and final pass, we replay any un-revoked blocks 242 * in the log. 243 */ 244 int jbd2_journal_recover(journal_t *journal) 245 { 246 int err, err2; 247 journal_superblock_t * sb; 248 249 struct recovery_info info; 250 251 memset(&info, 0, sizeof(info)); 252 sb = journal->j_superblock; 253 254 /* 255 * The journal superblock's s_start field (the current log head) 256 * is always zero if, and only if, the journal was cleanly 257 * unmounted. 258 */ 259 260 if (!sb->s_start) { 261 jbd_debug(1, "No recovery required, last transaction %d\n", 262 be32_to_cpu(sb->s_sequence)); 263 journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1; 264 return 0; 265 } 266 267 err = do_one_pass(journal, &info, PASS_SCAN); 268 if (!err) 269 err = do_one_pass(journal, &info, PASS_REVOKE); 270 if (!err) 271 err = do_one_pass(journal, &info, PASS_REPLAY); 272 273 jbd_debug(1, "JBD2: recovery, exit status %d, " 274 "recovered transactions %u to %u\n", 275 err, info.start_transaction, info.end_transaction); 276 jbd_debug(1, "JBD2: Replayed %d and revoked %d/%d blocks\n", 277 info.nr_replays, info.nr_revoke_hits, info.nr_revokes); 278 279 /* Restart the log at the next transaction ID, thus invalidating 280 * any existing commit records in the log. */ 281 journal->j_transaction_sequence = ++info.end_transaction; 282 283 jbd2_journal_clear_revoke(journal); 284 err2 = sync_blockdev(journal->j_fs_dev); 285 if (!err) 286 err = err2; 287 /* Make sure all replayed data is on permanent storage */ 288 if (journal->j_flags & JBD2_BARRIER) { 289 err2 = blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL); 290 if (!err) 291 err = err2; 292 } 293 return err; 294 } 295 296 /** 297 * jbd2_journal_skip_recovery - Start journal and wipe exiting records 298 * @journal: journal to startup 299 * 300 * Locate any valid recovery information from the journal and set up the 301 * journal structures in memory to ignore it (presumably because the 302 * caller has evidence that it is out of date). 303 * This function doesn't appear to be exported.. 304 * 305 * We perform one pass over the journal to allow us to tell the user how 306 * much recovery information is being erased, and to let us initialise 307 * the journal transaction sequence numbers to the next unused ID. 308 */ 309 int jbd2_journal_skip_recovery(journal_t *journal) 310 { 311 int err; 312 313 struct recovery_info info; 314 315 memset (&info, 0, sizeof(info)); 316 317 err = do_one_pass(journal, &info, PASS_SCAN); 318 319 if (err) { 320 printk(KERN_ERR "JBD2: error %d scanning journal\n", err); 321 ++journal->j_transaction_sequence; 322 } else { 323 #ifdef CONFIG_JBD2_DEBUG 324 int dropped = info.end_transaction - 325 be32_to_cpu(journal->j_superblock->s_sequence); 326 jbd_debug(1, 327 "JBD2: ignoring %d transaction%s from the journal.\n", 328 dropped, (dropped == 1) ? "" : "s"); 329 #endif 330 journal->j_transaction_sequence = ++info.end_transaction; 331 } 332 333 journal->j_tail = 0; 334 return err; 335 } 336 337 static inline unsigned long long read_tag_block(journal_t *journal, 338 journal_block_tag_t *tag) 339 { 340 unsigned long long block = be32_to_cpu(tag->t_blocknr); 341 if (jbd2_has_feature_64bit(journal)) 342 block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32; 343 return block; 344 } 345 346 /* 347 * calc_chksums calculates the checksums for the blocks described in the 348 * descriptor block. 349 */ 350 static int calc_chksums(journal_t *journal, struct buffer_head *bh, 351 unsigned long *next_log_block, __u32 *crc32_sum) 352 { 353 int i, num_blks, err; 354 unsigned long io_block; 355 struct buffer_head *obh; 356 357 num_blks = count_tags(journal, bh); 358 /* Calculate checksum of the descriptor block. */ 359 *crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size); 360 361 for (i = 0; i < num_blks; i++) { 362 io_block = (*next_log_block)++; 363 wrap(journal, *next_log_block); 364 err = jread(&obh, journal, io_block); 365 if (err) { 366 printk(KERN_ERR "JBD2: IO error %d recovering block " 367 "%lu in log\n", err, io_block); 368 return 1; 369 } else { 370 *crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data, 371 obh->b_size); 372 } 373 put_bh(obh); 374 } 375 return 0; 376 } 377 378 static int jbd2_commit_block_csum_verify(journal_t *j, void *buf) 379 { 380 struct commit_header *h; 381 __be32 provided; 382 __u32 calculated; 383 384 if (!jbd2_journal_has_csum_v2or3(j)) 385 return 1; 386 387 h = buf; 388 provided = h->h_chksum[0]; 389 h->h_chksum[0] = 0; 390 calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize); 391 h->h_chksum[0] = provided; 392 393 return provided == cpu_to_be32(calculated); 394 } 395 396 static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag, 397 void *buf, __u32 sequence) 398 { 399 journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag; 400 __u32 csum32; 401 __be32 seq; 402 403 if (!jbd2_journal_has_csum_v2or3(j)) 404 return 1; 405 406 seq = cpu_to_be32(sequence); 407 csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq)); 408 csum32 = jbd2_chksum(j, csum32, buf, j->j_blocksize); 409 410 if (jbd2_has_feature_csum3(j)) 411 return tag3->t_checksum == cpu_to_be32(csum32); 412 else 413 return tag->t_checksum == cpu_to_be16(csum32); 414 } 415 416 static int do_one_pass(journal_t *journal, 417 struct recovery_info *info, enum passtype pass) 418 { 419 unsigned int first_commit_ID, next_commit_ID; 420 unsigned long next_log_block; 421 int err, success = 0; 422 journal_superblock_t * sb; 423 journal_header_t * tmp; 424 struct buffer_head * bh; 425 unsigned int sequence; 426 int blocktype; 427 int tag_bytes = journal_tag_bytes(journal); 428 __u32 crc32_sum = ~0; /* Transactional Checksums */ 429 int descr_csum_size = 0; 430 int block_error = 0; 431 432 /* 433 * First thing is to establish what we expect to find in the log 434 * (in terms of transaction IDs), and where (in terms of log 435 * block offsets): query the superblock. 436 */ 437 438 sb = journal->j_superblock; 439 next_commit_ID = be32_to_cpu(sb->s_sequence); 440 next_log_block = be32_to_cpu(sb->s_start); 441 442 first_commit_ID = next_commit_ID; 443 if (pass == PASS_SCAN) 444 info->start_transaction = first_commit_ID; 445 446 jbd_debug(1, "Starting recovery pass %d\n", pass); 447 448 /* 449 * Now we walk through the log, transaction by transaction, 450 * making sure that each transaction has a commit block in the 451 * expected place. Each complete transaction gets replayed back 452 * into the main filesystem. 453 */ 454 455 while (1) { 456 int flags; 457 char * tagp; 458 journal_block_tag_t * tag; 459 struct buffer_head * obh; 460 struct buffer_head * nbh; 461 462 cond_resched(); 463 464 /* If we already know where to stop the log traversal, 465 * check right now that we haven't gone past the end of 466 * the log. */ 467 468 if (pass != PASS_SCAN) 469 if (tid_geq(next_commit_ID, info->end_transaction)) 470 break; 471 472 jbd_debug(2, "Scanning for sequence ID %u at %lu/%lu\n", 473 next_commit_ID, next_log_block, journal->j_last); 474 475 /* Skip over each chunk of the transaction looking 476 * either the next descriptor block or the final commit 477 * record. */ 478 479 jbd_debug(3, "JBD2: checking block %ld\n", next_log_block); 480 err = jread(&bh, journal, next_log_block); 481 if (err) 482 goto failed; 483 484 next_log_block++; 485 wrap(journal, next_log_block); 486 487 /* What kind of buffer is it? 488 * 489 * If it is a descriptor block, check that it has the 490 * expected sequence number. Otherwise, we're all done 491 * here. */ 492 493 tmp = (journal_header_t *)bh->b_data; 494 495 if (tmp->h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER)) { 496 brelse(bh); 497 break; 498 } 499 500 blocktype = be32_to_cpu(tmp->h_blocktype); 501 sequence = be32_to_cpu(tmp->h_sequence); 502 jbd_debug(3, "Found magic %d, sequence %d\n", 503 blocktype, sequence); 504 505 if (sequence != next_commit_ID) { 506 brelse(bh); 507 break; 508 } 509 510 /* OK, we have a valid descriptor block which matches 511 * all of the sequence number checks. What are we going 512 * to do with it? That depends on the pass... */ 513 514 switch(blocktype) { 515 case JBD2_DESCRIPTOR_BLOCK: 516 /* Verify checksum first */ 517 if (jbd2_journal_has_csum_v2or3(journal)) 518 descr_csum_size = 519 sizeof(struct jbd2_journal_block_tail); 520 if (descr_csum_size > 0 && 521 !jbd2_descriptor_block_csum_verify(journal, 522 bh->b_data)) { 523 printk(KERN_ERR "JBD2: Invalid checksum " 524 "recovering block %lu in log\n", 525 next_log_block); 526 err = -EFSBADCRC; 527 brelse(bh); 528 goto failed; 529 } 530 531 /* If it is a valid descriptor block, replay it 532 * in pass REPLAY; if journal_checksums enabled, then 533 * calculate checksums in PASS_SCAN, otherwise, 534 * just skip over the blocks it describes. */ 535 if (pass != PASS_REPLAY) { 536 if (pass == PASS_SCAN && 537 jbd2_has_feature_checksum(journal) && 538 !info->end_transaction) { 539 if (calc_chksums(journal, bh, 540 &next_log_block, 541 &crc32_sum)) { 542 put_bh(bh); 543 break; 544 } 545 put_bh(bh); 546 continue; 547 } 548 next_log_block += count_tags(journal, bh); 549 wrap(journal, next_log_block); 550 put_bh(bh); 551 continue; 552 } 553 554 /* A descriptor block: we can now write all of 555 * the data blocks. Yay, useful work is finally 556 * getting done here! */ 557 558 tagp = &bh->b_data[sizeof(journal_header_t)]; 559 while ((tagp - bh->b_data + tag_bytes) 560 <= journal->j_blocksize - descr_csum_size) { 561 unsigned long io_block; 562 563 tag = (journal_block_tag_t *) tagp; 564 flags = be16_to_cpu(tag->t_flags); 565 566 io_block = next_log_block++; 567 wrap(journal, next_log_block); 568 err = jread(&obh, journal, io_block); 569 if (err) { 570 /* Recover what we can, but 571 * report failure at the end. */ 572 success = err; 573 printk(KERN_ERR 574 "JBD2: IO error %d recovering " 575 "block %ld in log\n", 576 err, io_block); 577 } else { 578 unsigned long long blocknr; 579 580 J_ASSERT(obh != NULL); 581 blocknr = read_tag_block(journal, 582 tag); 583 584 /* If the block has been 585 * revoked, then we're all done 586 * here. */ 587 if (jbd2_journal_test_revoke 588 (journal, blocknr, 589 next_commit_ID)) { 590 brelse(obh); 591 ++info->nr_revoke_hits; 592 goto skip_write; 593 } 594 595 /* Look for block corruption */ 596 if (!jbd2_block_tag_csum_verify( 597 journal, tag, obh->b_data, 598 be32_to_cpu(tmp->h_sequence))) { 599 brelse(obh); 600 success = -EFSBADCRC; 601 printk(KERN_ERR "JBD2: Invalid " 602 "checksum recovering " 603 "data block %llu in " 604 "log\n", blocknr); 605 block_error = 1; 606 goto skip_write; 607 } 608 609 /* Find a buffer for the new 610 * data being restored */ 611 nbh = __getblk(journal->j_fs_dev, 612 blocknr, 613 journal->j_blocksize); 614 if (nbh == NULL) { 615 printk(KERN_ERR 616 "JBD2: Out of memory " 617 "during recovery.\n"); 618 err = -ENOMEM; 619 brelse(bh); 620 brelse(obh); 621 goto failed; 622 } 623 624 lock_buffer(nbh); 625 memcpy(nbh->b_data, obh->b_data, 626 journal->j_blocksize); 627 if (flags & JBD2_FLAG_ESCAPE) { 628 *((__be32 *)nbh->b_data) = 629 cpu_to_be32(JBD2_MAGIC_NUMBER); 630 } 631 632 BUFFER_TRACE(nbh, "marking dirty"); 633 set_buffer_uptodate(nbh); 634 mark_buffer_dirty(nbh); 635 BUFFER_TRACE(nbh, "marking uptodate"); 636 ++info->nr_replays; 637 /* ll_rw_block(WRITE, 1, &nbh); */ 638 unlock_buffer(nbh); 639 brelse(obh); 640 brelse(nbh); 641 } 642 643 skip_write: 644 tagp += tag_bytes; 645 if (!(flags & JBD2_FLAG_SAME_UUID)) 646 tagp += 16; 647 648 if (flags & JBD2_FLAG_LAST_TAG) 649 break; 650 } 651 652 brelse(bh); 653 continue; 654 655 case JBD2_COMMIT_BLOCK: 656 /* How to differentiate between interrupted commit 657 * and journal corruption ? 658 * 659 * {nth transaction} 660 * Checksum Verification Failed 661 * | 662 * ____________________ 663 * | | 664 * async_commit sync_commit 665 * | | 666 * | GO TO NEXT "Journal Corruption" 667 * | TRANSACTION 668 * | 669 * {(n+1)th transanction} 670 * | 671 * _______|______________ 672 * | | 673 * Commit block found Commit block not found 674 * | | 675 * "Journal Corruption" | 676 * _____________|_________ 677 * | | 678 * nth trans corrupt OR nth trans 679 * and (n+1)th interrupted interrupted 680 * before commit block 681 * could reach the disk. 682 * (Cannot find the difference in above 683 * mentioned conditions. Hence assume 684 * "Interrupted Commit".) 685 */ 686 687 /* Found an expected commit block: if checksums 688 * are present verify them in PASS_SCAN; else not 689 * much to do other than move on to the next sequence 690 * number. */ 691 if (pass == PASS_SCAN && 692 jbd2_has_feature_checksum(journal)) { 693 int chksum_err, chksum_seen; 694 struct commit_header *cbh = 695 (struct commit_header *)bh->b_data; 696 unsigned found_chksum = 697 be32_to_cpu(cbh->h_chksum[0]); 698 699 chksum_err = chksum_seen = 0; 700 701 if (info->end_transaction) { 702 journal->j_failed_commit = 703 info->end_transaction; 704 brelse(bh); 705 break; 706 } 707 708 if (crc32_sum == found_chksum && 709 cbh->h_chksum_type == JBD2_CRC32_CHKSUM && 710 cbh->h_chksum_size == 711 JBD2_CRC32_CHKSUM_SIZE) 712 chksum_seen = 1; 713 else if (!(cbh->h_chksum_type == 0 && 714 cbh->h_chksum_size == 0 && 715 found_chksum == 0 && 716 !chksum_seen)) 717 /* 718 * If fs is mounted using an old kernel and then 719 * kernel with journal_chksum is used then we 720 * get a situation where the journal flag has 721 * checksum flag set but checksums are not 722 * present i.e chksum = 0, in the individual 723 * commit blocks. 724 * Hence to avoid checksum failures, in this 725 * situation, this extra check is added. 726 */ 727 chksum_err = 1; 728 729 if (chksum_err) { 730 info->end_transaction = next_commit_ID; 731 732 if (!jbd2_has_feature_async_commit(journal)) { 733 journal->j_failed_commit = 734 next_commit_ID; 735 brelse(bh); 736 break; 737 } 738 } 739 crc32_sum = ~0; 740 } 741 if (pass == PASS_SCAN && 742 !jbd2_commit_block_csum_verify(journal, 743 bh->b_data)) { 744 info->end_transaction = next_commit_ID; 745 746 if (!jbd2_has_feature_async_commit(journal)) { 747 journal->j_failed_commit = 748 next_commit_ID; 749 brelse(bh); 750 break; 751 } 752 } 753 brelse(bh); 754 next_commit_ID++; 755 continue; 756 757 case JBD2_REVOKE_BLOCK: 758 /* If we aren't in the REVOKE pass, then we can 759 * just skip over this block. */ 760 if (pass != PASS_REVOKE) { 761 brelse(bh); 762 continue; 763 } 764 765 err = scan_revoke_records(journal, bh, 766 next_commit_ID, info); 767 brelse(bh); 768 if (err) 769 goto failed; 770 continue; 771 772 default: 773 jbd_debug(3, "Unrecognised magic %d, end of scan.\n", 774 blocktype); 775 brelse(bh); 776 goto done; 777 } 778 } 779 780 done: 781 /* 782 * We broke out of the log scan loop: either we came to the 783 * known end of the log or we found an unexpected block in the 784 * log. If the latter happened, then we know that the "current" 785 * transaction marks the end of the valid log. 786 */ 787 788 if (pass == PASS_SCAN) { 789 if (!info->end_transaction) 790 info->end_transaction = next_commit_ID; 791 } else { 792 /* It's really bad news if different passes end up at 793 * different places (but possible due to IO errors). */ 794 if (info->end_transaction != next_commit_ID) { 795 printk(KERN_ERR "JBD2: recovery pass %d ended at " 796 "transaction %u, expected %u\n", 797 pass, next_commit_ID, info->end_transaction); 798 if (!success) 799 success = -EIO; 800 } 801 } 802 if (block_error && success == 0) 803 success = -EIO; 804 return success; 805 806 failed: 807 return err; 808 } 809 810 /* Scan a revoke record, marking all blocks mentioned as revoked. */ 811 812 static int scan_revoke_records(journal_t *journal, struct buffer_head *bh, 813 tid_t sequence, struct recovery_info *info) 814 { 815 jbd2_journal_revoke_header_t *header; 816 int offset, max; 817 int csum_size = 0; 818 __u32 rcount; 819 int record_len = 4; 820 821 header = (jbd2_journal_revoke_header_t *) bh->b_data; 822 offset = sizeof(jbd2_journal_revoke_header_t); 823 rcount = be32_to_cpu(header->r_count); 824 825 if (!jbd2_descriptor_block_csum_verify(journal, header)) 826 return -EFSBADCRC; 827 828 if (jbd2_journal_has_csum_v2or3(journal)) 829 csum_size = sizeof(struct jbd2_journal_block_tail); 830 if (rcount > journal->j_blocksize - csum_size) 831 return -EINVAL; 832 max = rcount; 833 834 if (jbd2_has_feature_64bit(journal)) 835 record_len = 8; 836 837 while (offset + record_len <= max) { 838 unsigned long long blocknr; 839 int err; 840 841 if (record_len == 4) 842 blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset))); 843 else 844 blocknr = be64_to_cpu(* ((__be64 *) (bh->b_data+offset))); 845 offset += record_len; 846 err = jbd2_journal_set_revoke(journal, blocknr, sequence); 847 if (err) 848 return err; 849 ++info->nr_revokes; 850 } 851 return 0; 852 } 853