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 unsigned long head_block; 33 34 int nr_replays; 35 int nr_revokes; 36 int nr_revoke_hits; 37 }; 38 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_total_len) 79 max = journal->j_total_len; 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 bh_readahead_batch(nbufs, bufs, 0); 105 journal_brelse_array(bufs, nbufs); 106 nbufs = 0; 107 } 108 } else 109 brelse(bh); 110 } 111 112 if (nbufs) 113 bh_readahead_batch(nbufs, bufs, 0); 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_total_len) { 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 /* 157 * If this is a brand new buffer, start readahead. 158 * Otherwise, we assume we are already reading it. 159 */ 160 bool need_readahead = !buffer_req(bh); 161 162 bh_read_nowait(bh, 0); 163 if (need_readahead) 164 do_readahead(journal, offset); 165 wait_on_buffer(bh); 166 } 167 168 if (!buffer_uptodate(bh)) { 169 printk(KERN_ERR "JBD2: Failed to read block at offset %u\n", 170 offset); 171 brelse(bh); 172 return -EIO; 173 } 174 175 *bhp = bh; 176 return 0; 177 } 178 179 static int jbd2_descriptor_block_csum_verify(journal_t *j, void *buf) 180 { 181 struct jbd2_journal_block_tail *tail; 182 __be32 provided; 183 __u32 calculated; 184 185 if (!jbd2_journal_has_csum_v2or3(j)) 186 return 1; 187 188 tail = (struct jbd2_journal_block_tail *)((char *)buf + 189 j->j_blocksize - sizeof(struct jbd2_journal_block_tail)); 190 provided = tail->t_checksum; 191 tail->t_checksum = 0; 192 calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize); 193 tail->t_checksum = provided; 194 195 return provided == cpu_to_be32(calculated); 196 } 197 198 /* 199 * Count the number of in-use tags in a journal descriptor block. 200 */ 201 202 static int count_tags(journal_t *journal, struct buffer_head *bh) 203 { 204 char * tagp; 205 journal_block_tag_t tag; 206 int nr = 0, size = journal->j_blocksize; 207 int tag_bytes = journal_tag_bytes(journal); 208 209 if (jbd2_journal_has_csum_v2or3(journal)) 210 size -= sizeof(struct jbd2_journal_block_tail); 211 212 tagp = &bh->b_data[sizeof(journal_header_t)]; 213 214 while ((tagp - bh->b_data + tag_bytes) <= size) { 215 memcpy(&tag, tagp, sizeof(tag)); 216 217 nr++; 218 tagp += tag_bytes; 219 if (!(tag.t_flags & cpu_to_be16(JBD2_FLAG_SAME_UUID))) 220 tagp += 16; 221 222 if (tag.t_flags & cpu_to_be16(JBD2_FLAG_LAST_TAG)) 223 break; 224 } 225 226 return nr; 227 } 228 229 230 /* Make sure we wrap around the log correctly! */ 231 #define wrap(journal, var) \ 232 do { \ 233 if (var >= (journal)->j_last) \ 234 var -= ((journal)->j_last - (journal)->j_first); \ 235 } while (0) 236 237 static int fc_do_one_pass(journal_t *journal, 238 struct recovery_info *info, enum passtype pass) 239 { 240 unsigned int expected_commit_id = info->end_transaction; 241 unsigned long next_fc_block; 242 struct buffer_head *bh; 243 int err = 0; 244 245 next_fc_block = journal->j_fc_first; 246 if (!journal->j_fc_replay_callback) 247 return 0; 248 249 while (next_fc_block <= journal->j_fc_last) { 250 jbd2_debug(3, "Fast commit replay: next block %ld\n", 251 next_fc_block); 252 err = jread(&bh, journal, next_fc_block); 253 if (err) { 254 jbd2_debug(3, "Fast commit replay: read error\n"); 255 break; 256 } 257 258 err = journal->j_fc_replay_callback(journal, bh, pass, 259 next_fc_block - journal->j_fc_first, 260 expected_commit_id); 261 brelse(bh); 262 next_fc_block++; 263 if (err < 0 || err == JBD2_FC_REPLAY_STOP) 264 break; 265 err = 0; 266 } 267 268 if (err) 269 jbd2_debug(3, "Fast commit replay failed, err = %d\n", err); 270 271 return err; 272 } 273 274 /** 275 * jbd2_journal_recover - recovers a on-disk journal 276 * @journal: the journal to recover 277 * 278 * The primary function for recovering the log contents when mounting a 279 * journaled device. 280 * 281 * Recovery is done in three passes. In the first pass, we look for the 282 * end of the log. In the second, we assemble the list of revoke 283 * blocks. In the third and final pass, we replay any un-revoked blocks 284 * in the log. 285 */ 286 int jbd2_journal_recover(journal_t *journal) 287 { 288 int err, err2; 289 journal_superblock_t * sb; 290 291 struct recovery_info info; 292 293 memset(&info, 0, sizeof(info)); 294 sb = journal->j_superblock; 295 296 /* 297 * The journal superblock's s_start field (the current log head) 298 * is always zero if, and only if, the journal was cleanly 299 * unmounted. 300 */ 301 if (!sb->s_start) { 302 jbd2_debug(1, "No recovery required, last transaction %d, head block %u\n", 303 be32_to_cpu(sb->s_sequence), be32_to_cpu(sb->s_head)); 304 journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1; 305 journal->j_head = be32_to_cpu(sb->s_head); 306 return 0; 307 } 308 309 err = do_one_pass(journal, &info, PASS_SCAN); 310 if (!err) 311 err = do_one_pass(journal, &info, PASS_REVOKE); 312 if (!err) 313 err = do_one_pass(journal, &info, PASS_REPLAY); 314 315 jbd2_debug(1, "JBD2: recovery, exit status %d, " 316 "recovered transactions %u to %u\n", 317 err, info.start_transaction, info.end_transaction); 318 jbd2_debug(1, "JBD2: Replayed %d and revoked %d/%d blocks\n", 319 info.nr_replays, info.nr_revoke_hits, info.nr_revokes); 320 321 /* Restart the log at the next transaction ID, thus invalidating 322 * any existing commit records in the log. */ 323 journal->j_transaction_sequence = ++info.end_transaction; 324 journal->j_head = info.head_block; 325 jbd2_debug(1, "JBD2: last transaction %d, head block %lu\n", 326 journal->j_transaction_sequence, journal->j_head); 327 328 jbd2_journal_clear_revoke(journal); 329 err2 = sync_blockdev(journal->j_fs_dev); 330 if (!err) 331 err = err2; 332 /* Make sure all replayed data is on permanent storage */ 333 if (journal->j_flags & JBD2_BARRIER) { 334 err2 = blkdev_issue_flush(journal->j_fs_dev); 335 if (!err) 336 err = err2; 337 } 338 return err; 339 } 340 341 /** 342 * jbd2_journal_skip_recovery - Start journal and wipe exiting records 343 * @journal: journal to startup 344 * 345 * Locate any valid recovery information from the journal and set up the 346 * journal structures in memory to ignore it (presumably because the 347 * caller has evidence that it is out of date). 348 * This function doesn't appear to be exported.. 349 * 350 * We perform one pass over the journal to allow us to tell the user how 351 * much recovery information is being erased, and to let us initialise 352 * the journal transaction sequence numbers to the next unused ID. 353 */ 354 int jbd2_journal_skip_recovery(journal_t *journal) 355 { 356 int err; 357 358 struct recovery_info info; 359 360 memset (&info, 0, sizeof(info)); 361 362 err = do_one_pass(journal, &info, PASS_SCAN); 363 364 if (err) { 365 printk(KERN_ERR "JBD2: error %d scanning journal\n", err); 366 ++journal->j_transaction_sequence; 367 journal->j_head = journal->j_first; 368 } else { 369 #ifdef CONFIG_JBD2_DEBUG 370 int dropped = info.end_transaction - 371 be32_to_cpu(journal->j_superblock->s_sequence); 372 jbd2_debug(1, 373 "JBD2: ignoring %d transaction%s from the journal.\n", 374 dropped, (dropped == 1) ? "" : "s"); 375 #endif 376 journal->j_transaction_sequence = ++info.end_transaction; 377 journal->j_head = info.head_block; 378 } 379 380 journal->j_tail = 0; 381 return err; 382 } 383 384 static inline unsigned long long read_tag_block(journal_t *journal, 385 journal_block_tag_t *tag) 386 { 387 unsigned long long block = be32_to_cpu(tag->t_blocknr); 388 if (jbd2_has_feature_64bit(journal)) 389 block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32; 390 return block; 391 } 392 393 /* 394 * calc_chksums calculates the checksums for the blocks described in the 395 * descriptor block. 396 */ 397 static int calc_chksums(journal_t *journal, struct buffer_head *bh, 398 unsigned long *next_log_block, __u32 *crc32_sum) 399 { 400 int i, num_blks, err; 401 unsigned long io_block; 402 struct buffer_head *obh; 403 404 num_blks = count_tags(journal, bh); 405 /* Calculate checksum of the descriptor block. */ 406 *crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size); 407 408 for (i = 0; i < num_blks; i++) { 409 io_block = (*next_log_block)++; 410 wrap(journal, *next_log_block); 411 err = jread(&obh, journal, io_block); 412 if (err) { 413 printk(KERN_ERR "JBD2: IO error %d recovering block " 414 "%lu in log\n", err, io_block); 415 return 1; 416 } else { 417 *crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data, 418 obh->b_size); 419 } 420 put_bh(obh); 421 } 422 return 0; 423 } 424 425 static int jbd2_commit_block_csum_verify(journal_t *j, void *buf) 426 { 427 struct commit_header *h; 428 __be32 provided; 429 __u32 calculated; 430 431 if (!jbd2_journal_has_csum_v2or3(j)) 432 return 1; 433 434 h = buf; 435 provided = h->h_chksum[0]; 436 h->h_chksum[0] = 0; 437 calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize); 438 h->h_chksum[0] = provided; 439 440 return provided == cpu_to_be32(calculated); 441 } 442 443 static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag, 444 journal_block_tag3_t *tag3, 445 void *buf, __u32 sequence) 446 { 447 __u32 csum32; 448 __be32 seq; 449 450 if (!jbd2_journal_has_csum_v2or3(j)) 451 return 1; 452 453 seq = cpu_to_be32(sequence); 454 csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq)); 455 csum32 = jbd2_chksum(j, csum32, buf, j->j_blocksize); 456 457 if (jbd2_has_feature_csum3(j)) 458 return tag3->t_checksum == cpu_to_be32(csum32); 459 else 460 return tag->t_checksum == cpu_to_be16(csum32); 461 } 462 463 static int do_one_pass(journal_t *journal, 464 struct recovery_info *info, enum passtype pass) 465 { 466 unsigned int first_commit_ID, next_commit_ID; 467 unsigned long next_log_block, head_block; 468 int err, success = 0; 469 journal_superblock_t * sb; 470 journal_header_t * tmp; 471 struct buffer_head * bh; 472 unsigned int sequence; 473 int blocktype; 474 int tag_bytes = journal_tag_bytes(journal); 475 __u32 crc32_sum = ~0; /* Transactional Checksums */ 476 int descr_csum_size = 0; 477 int block_error = 0; 478 bool need_check_commit_time = false; 479 __u64 last_trans_commit_time = 0, commit_time; 480 481 /* 482 * First thing is to establish what we expect to find in the log 483 * (in terms of transaction IDs), and where (in terms of log 484 * block offsets): query the superblock. 485 */ 486 487 sb = journal->j_superblock; 488 next_commit_ID = be32_to_cpu(sb->s_sequence); 489 next_log_block = be32_to_cpu(sb->s_start); 490 head_block = next_log_block; 491 492 first_commit_ID = next_commit_ID; 493 if (pass == PASS_SCAN) 494 info->start_transaction = first_commit_ID; 495 496 jbd2_debug(1, "Starting recovery pass %d\n", pass); 497 498 /* 499 * Now we walk through the log, transaction by transaction, 500 * making sure that each transaction has a commit block in the 501 * expected place. Each complete transaction gets replayed back 502 * into the main filesystem. 503 */ 504 505 while (1) { 506 int flags; 507 char * tagp; 508 journal_block_tag_t tag; 509 struct buffer_head * obh; 510 struct buffer_head * nbh; 511 512 cond_resched(); 513 514 /* If we already know where to stop the log traversal, 515 * check right now that we haven't gone past the end of 516 * the log. */ 517 518 if (pass != PASS_SCAN) 519 if (tid_geq(next_commit_ID, info->end_transaction)) 520 break; 521 522 jbd2_debug(2, "Scanning for sequence ID %u at %lu/%lu\n", 523 next_commit_ID, next_log_block, journal->j_last); 524 525 /* Skip over each chunk of the transaction looking 526 * either the next descriptor block or the final commit 527 * record. */ 528 529 jbd2_debug(3, "JBD2: checking block %ld\n", next_log_block); 530 err = jread(&bh, journal, next_log_block); 531 if (err) 532 goto failed; 533 534 next_log_block++; 535 wrap(journal, next_log_block); 536 537 /* What kind of buffer is it? 538 * 539 * If it is a descriptor block, check that it has the 540 * expected sequence number. Otherwise, we're all done 541 * here. */ 542 543 tmp = (journal_header_t *)bh->b_data; 544 545 if (tmp->h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER)) { 546 brelse(bh); 547 break; 548 } 549 550 blocktype = be32_to_cpu(tmp->h_blocktype); 551 sequence = be32_to_cpu(tmp->h_sequence); 552 jbd2_debug(3, "Found magic %d, sequence %d\n", 553 blocktype, sequence); 554 555 if (sequence != next_commit_ID) { 556 brelse(bh); 557 break; 558 } 559 560 /* OK, we have a valid descriptor block which matches 561 * all of the sequence number checks. What are we going 562 * to do with it? That depends on the pass... */ 563 564 switch(blocktype) { 565 case JBD2_DESCRIPTOR_BLOCK: 566 /* Verify checksum first */ 567 if (jbd2_journal_has_csum_v2or3(journal)) 568 descr_csum_size = 569 sizeof(struct jbd2_journal_block_tail); 570 if (descr_csum_size > 0 && 571 !jbd2_descriptor_block_csum_verify(journal, 572 bh->b_data)) { 573 /* 574 * PASS_SCAN can see stale blocks due to lazy 575 * journal init. Don't error out on those yet. 576 */ 577 if (pass != PASS_SCAN) { 578 pr_err("JBD2: Invalid checksum recovering block %lu in log\n", 579 next_log_block); 580 err = -EFSBADCRC; 581 brelse(bh); 582 goto failed; 583 } 584 need_check_commit_time = true; 585 jbd2_debug(1, 586 "invalid descriptor block found in %lu\n", 587 next_log_block); 588 } 589 590 /* If it is a valid descriptor block, replay it 591 * in pass REPLAY; if journal_checksums enabled, then 592 * calculate checksums in PASS_SCAN, otherwise, 593 * just skip over the blocks it describes. */ 594 if (pass != PASS_REPLAY) { 595 if (pass == PASS_SCAN && 596 jbd2_has_feature_checksum(journal) && 597 !need_check_commit_time && 598 !info->end_transaction) { 599 if (calc_chksums(journal, bh, 600 &next_log_block, 601 &crc32_sum)) { 602 put_bh(bh); 603 break; 604 } 605 put_bh(bh); 606 continue; 607 } 608 next_log_block += count_tags(journal, bh); 609 wrap(journal, next_log_block); 610 put_bh(bh); 611 continue; 612 } 613 614 /* A descriptor block: we can now write all of 615 * the data blocks. Yay, useful work is finally 616 * getting done here! */ 617 618 tagp = &bh->b_data[sizeof(journal_header_t)]; 619 while ((tagp - bh->b_data + tag_bytes) 620 <= journal->j_blocksize - descr_csum_size) { 621 unsigned long io_block; 622 623 memcpy(&tag, tagp, sizeof(tag)); 624 flags = be16_to_cpu(tag.t_flags); 625 626 io_block = next_log_block++; 627 wrap(journal, next_log_block); 628 err = jread(&obh, journal, io_block); 629 if (err) { 630 /* Recover what we can, but 631 * report failure at the end. */ 632 success = err; 633 printk(KERN_ERR 634 "JBD2: IO error %d recovering " 635 "block %ld in log\n", 636 err, io_block); 637 } else { 638 unsigned long long blocknr; 639 640 J_ASSERT(obh != NULL); 641 blocknr = read_tag_block(journal, 642 &tag); 643 644 /* If the block has been 645 * revoked, then we're all done 646 * here. */ 647 if (jbd2_journal_test_revoke 648 (journal, blocknr, 649 next_commit_ID)) { 650 brelse(obh); 651 ++info->nr_revoke_hits; 652 goto skip_write; 653 } 654 655 /* Look for block corruption */ 656 if (!jbd2_block_tag_csum_verify( 657 journal, &tag, (journal_block_tag3_t *)tagp, 658 obh->b_data, be32_to_cpu(tmp->h_sequence))) { 659 brelse(obh); 660 success = -EFSBADCRC; 661 printk(KERN_ERR "JBD2: Invalid " 662 "checksum recovering " 663 "data block %llu in " 664 "log\n", blocknr); 665 block_error = 1; 666 goto skip_write; 667 } 668 669 /* Find a buffer for the new 670 * data being restored */ 671 nbh = __getblk(journal->j_fs_dev, 672 blocknr, 673 journal->j_blocksize); 674 if (nbh == NULL) { 675 printk(KERN_ERR 676 "JBD2: Out of memory " 677 "during recovery.\n"); 678 err = -ENOMEM; 679 brelse(bh); 680 brelse(obh); 681 goto failed; 682 } 683 684 lock_buffer(nbh); 685 memcpy(nbh->b_data, obh->b_data, 686 journal->j_blocksize); 687 if (flags & JBD2_FLAG_ESCAPE) { 688 *((__be32 *)nbh->b_data) = 689 cpu_to_be32(JBD2_MAGIC_NUMBER); 690 } 691 692 BUFFER_TRACE(nbh, "marking dirty"); 693 set_buffer_uptodate(nbh); 694 mark_buffer_dirty(nbh); 695 BUFFER_TRACE(nbh, "marking uptodate"); 696 ++info->nr_replays; 697 unlock_buffer(nbh); 698 brelse(obh); 699 brelse(nbh); 700 } 701 702 skip_write: 703 tagp += tag_bytes; 704 if (!(flags & JBD2_FLAG_SAME_UUID)) 705 tagp += 16; 706 707 if (flags & JBD2_FLAG_LAST_TAG) 708 break; 709 } 710 711 brelse(bh); 712 continue; 713 714 case JBD2_COMMIT_BLOCK: 715 /* How to differentiate between interrupted commit 716 * and journal corruption ? 717 * 718 * {nth transaction} 719 * Checksum Verification Failed 720 * | 721 * ____________________ 722 * | | 723 * async_commit sync_commit 724 * | | 725 * | GO TO NEXT "Journal Corruption" 726 * | TRANSACTION 727 * | 728 * {(n+1)th transanction} 729 * | 730 * _______|______________ 731 * | | 732 * Commit block found Commit block not found 733 * | | 734 * "Journal Corruption" | 735 * _____________|_________ 736 * | | 737 * nth trans corrupt OR nth trans 738 * and (n+1)th interrupted interrupted 739 * before commit block 740 * could reach the disk. 741 * (Cannot find the difference in above 742 * mentioned conditions. Hence assume 743 * "Interrupted Commit".) 744 */ 745 commit_time = be64_to_cpu( 746 ((struct commit_header *)bh->b_data)->h_commit_sec); 747 /* 748 * If need_check_commit_time is set, it means we are in 749 * PASS_SCAN and csum verify failed before. If 750 * commit_time is increasing, it's the same journal, 751 * otherwise it is stale journal block, just end this 752 * recovery. 753 */ 754 if (need_check_commit_time) { 755 if (commit_time >= last_trans_commit_time) { 756 pr_err("JBD2: Invalid checksum found in transaction %u\n", 757 next_commit_ID); 758 err = -EFSBADCRC; 759 brelse(bh); 760 goto failed; 761 } 762 ignore_crc_mismatch: 763 /* 764 * It likely does not belong to same journal, 765 * just end this recovery with success. 766 */ 767 jbd2_debug(1, "JBD2: Invalid checksum ignored in transaction %u, likely stale data\n", 768 next_commit_ID); 769 brelse(bh); 770 goto done; 771 } 772 773 /* 774 * Found an expected commit block: if checksums 775 * are present, verify them in PASS_SCAN; else not 776 * much to do other than move on to the next sequence 777 * number. 778 */ 779 if (pass == PASS_SCAN && 780 jbd2_has_feature_checksum(journal)) { 781 struct commit_header *cbh = 782 (struct commit_header *)bh->b_data; 783 unsigned found_chksum = 784 be32_to_cpu(cbh->h_chksum[0]); 785 786 if (info->end_transaction) { 787 journal->j_failed_commit = 788 info->end_transaction; 789 brelse(bh); 790 break; 791 } 792 793 /* Neither checksum match nor unused? */ 794 if (!((crc32_sum == found_chksum && 795 cbh->h_chksum_type == 796 JBD2_CRC32_CHKSUM && 797 cbh->h_chksum_size == 798 JBD2_CRC32_CHKSUM_SIZE) || 799 (cbh->h_chksum_type == 0 && 800 cbh->h_chksum_size == 0 && 801 found_chksum == 0))) 802 goto chksum_error; 803 804 crc32_sum = ~0; 805 } 806 if (pass == PASS_SCAN && 807 !jbd2_commit_block_csum_verify(journal, 808 bh->b_data)) { 809 chksum_error: 810 if (commit_time < last_trans_commit_time) 811 goto ignore_crc_mismatch; 812 info->end_transaction = next_commit_ID; 813 info->head_block = head_block; 814 815 if (!jbd2_has_feature_async_commit(journal)) { 816 journal->j_failed_commit = 817 next_commit_ID; 818 brelse(bh); 819 break; 820 } 821 } 822 if (pass == PASS_SCAN) { 823 last_trans_commit_time = commit_time; 824 head_block = next_log_block; 825 } 826 brelse(bh); 827 next_commit_ID++; 828 continue; 829 830 case JBD2_REVOKE_BLOCK: 831 /* 832 * Check revoke block crc in pass_scan, if csum verify 833 * failed, check commit block time later. 834 */ 835 if (pass == PASS_SCAN && 836 !jbd2_descriptor_block_csum_verify(journal, 837 bh->b_data)) { 838 jbd2_debug(1, "JBD2: invalid revoke block found in %lu\n", 839 next_log_block); 840 need_check_commit_time = true; 841 } 842 /* If we aren't in the REVOKE pass, then we can 843 * just skip over this block. */ 844 if (pass != PASS_REVOKE) { 845 brelse(bh); 846 continue; 847 } 848 849 err = scan_revoke_records(journal, bh, 850 next_commit_ID, info); 851 brelse(bh); 852 if (err) 853 goto failed; 854 continue; 855 856 default: 857 jbd2_debug(3, "Unrecognised magic %d, end of scan.\n", 858 blocktype); 859 brelse(bh); 860 goto done; 861 } 862 } 863 864 done: 865 /* 866 * We broke out of the log scan loop: either we came to the 867 * known end of the log or we found an unexpected block in the 868 * log. If the latter happened, then we know that the "current" 869 * transaction marks the end of the valid log. 870 */ 871 872 if (pass == PASS_SCAN) { 873 if (!info->end_transaction) 874 info->end_transaction = next_commit_ID; 875 if (!info->head_block) 876 info->head_block = head_block; 877 } else { 878 /* It's really bad news if different passes end up at 879 * different places (but possible due to IO errors). */ 880 if (info->end_transaction != next_commit_ID) { 881 printk(KERN_ERR "JBD2: recovery pass %d ended at " 882 "transaction %u, expected %u\n", 883 pass, next_commit_ID, info->end_transaction); 884 if (!success) 885 success = -EIO; 886 } 887 } 888 889 if (jbd2_has_feature_fast_commit(journal) && pass != PASS_REVOKE) { 890 err = fc_do_one_pass(journal, info, pass); 891 if (err) 892 success = err; 893 } 894 895 if (block_error && success == 0) 896 success = -EIO; 897 return success; 898 899 failed: 900 return err; 901 } 902 903 /* Scan a revoke record, marking all blocks mentioned as revoked. */ 904 905 static int scan_revoke_records(journal_t *journal, struct buffer_head *bh, 906 tid_t sequence, struct recovery_info *info) 907 { 908 jbd2_journal_revoke_header_t *header; 909 int offset, max; 910 unsigned csum_size = 0; 911 __u32 rcount; 912 int record_len = 4; 913 914 header = (jbd2_journal_revoke_header_t *) bh->b_data; 915 offset = sizeof(jbd2_journal_revoke_header_t); 916 rcount = be32_to_cpu(header->r_count); 917 918 if (jbd2_journal_has_csum_v2or3(journal)) 919 csum_size = sizeof(struct jbd2_journal_block_tail); 920 if (rcount > journal->j_blocksize - csum_size) 921 return -EINVAL; 922 max = rcount; 923 924 if (jbd2_has_feature_64bit(journal)) 925 record_len = 8; 926 927 while (offset + record_len <= max) { 928 unsigned long long blocknr; 929 int err; 930 931 if (record_len == 4) 932 blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset))); 933 else 934 blocknr = be64_to_cpu(* ((__be64 *) (bh->b_data+offset))); 935 offset += record_len; 936 err = jbd2_journal_set_revoke(journal, blocknr, sequence); 937 if (err) 938 return err; 939 ++info->nr_revokes; 940 } 941 return 0; 942 } 943