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 */ 28struct 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 39static int do_one_pass(journal_t *journal, 40 struct recovery_info *info, enum passtype pass); 41static 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 */ 47static 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 67static 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 116failed: 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 129static 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 179static 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 202static 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) \ 232do { \ 233 if (var >= (journal)->j_last) \ 234 var -= ((journal)->j_last - (journal)->j_first); \ 235} while (0) 236 237static 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 */ 286int jbd2_journal_recover(journal_t *journal) 287{ 288 int err, err2; 289 journal_superblock_t * sb; 290 291 struct recovery_info info; 292 errseq_t wb_err; 293 struct address_space *mapping; 294 295 memset(&info, 0, sizeof(info)); 296 sb = journal->j_superblock; 297 298 /* 299 * The journal superblock's s_start field (the current log head) 300 * is always zero if, and only if, the journal was cleanly 301 * unmounted. 302 */ 303 if (!sb->s_start) { 304 jbd2_debug(1, "No recovery required, last transaction %d, head block %u\n", 305 be32_to_cpu(sb->s_sequence), be32_to_cpu(sb->s_head)); 306 journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1; 307 journal->j_head = be32_to_cpu(sb->s_head); 308 return 0; 309 } 310 311 wb_err = 0; 312 mapping = journal->j_fs_dev->bd_inode->i_mapping; 313 errseq_check_and_advance(&mapping->wb_err, &wb_err); 314 err = do_one_pass(journal, &info, PASS_SCAN); 315 if (!err) 316 err = do_one_pass(journal, &info, PASS_REVOKE); 317 if (!err) 318 err = do_one_pass(journal, &info, PASS_REPLAY); 319 320 jbd2_debug(1, "JBD2: recovery, exit status %d, " 321 "recovered transactions %u to %u\n", 322 err, info.start_transaction, info.end_transaction); 323 jbd2_debug(1, "JBD2: Replayed %d and revoked %d/%d blocks\n", 324 info.nr_replays, info.nr_revoke_hits, info.nr_revokes); 325 326 /* Restart the log at the next transaction ID, thus invalidating 327 * any existing commit records in the log. */ 328 journal->j_transaction_sequence = ++info.end_transaction; 329 journal->j_head = info.head_block; 330 jbd2_debug(1, "JBD2: last transaction %d, head block %lu\n", 331 journal->j_transaction_sequence, journal->j_head); 332 333 jbd2_journal_clear_revoke(journal); 334 err2 = sync_blockdev(journal->j_fs_dev); 335 if (!err) 336 err = err2; 337 err2 = errseq_check_and_advance(&mapping->wb_err, &wb_err); 338 if (!err) 339 err = err2; 340 /* Make sure all replayed data is on permanent storage */ 341 if (journal->j_flags & JBD2_BARRIER) { 342 err2 = blkdev_issue_flush(journal->j_fs_dev); 343 if (!err) 344 err = err2; 345 } 346 return err; 347} 348 349/** 350 * jbd2_journal_skip_recovery - Start journal and wipe exiting records 351 * @journal: journal to startup 352 * 353 * Locate any valid recovery information from the journal and set up the 354 * journal structures in memory to ignore it (presumably because the 355 * caller has evidence that it is out of date). 356 * This function doesn't appear to be exported.. 357 * 358 * We perform one pass over the journal to allow us to tell the user how 359 * much recovery information is being erased, and to let us initialise 360 * the journal transaction sequence numbers to the next unused ID. 361 */ 362int jbd2_journal_skip_recovery(journal_t *journal) 363{ 364 int err; 365 366 struct recovery_info info; 367 368 memset (&info, 0, sizeof(info)); 369 370 err = do_one_pass(journal, &info, PASS_SCAN); 371 372 if (err) { 373 printk(KERN_ERR "JBD2: error %d scanning journal\n", err); 374 ++journal->j_transaction_sequence; 375 journal->j_head = journal->j_first; 376 } else { 377#ifdef CONFIG_JBD2_DEBUG 378 int dropped = info.end_transaction - 379 be32_to_cpu(journal->j_superblock->s_sequence); 380 jbd2_debug(1, 381 "JBD2: ignoring %d transaction%s from the journal.\n", 382 dropped, (dropped == 1) ? "" : "s"); 383#endif 384 journal->j_transaction_sequence = ++info.end_transaction; 385 journal->j_head = info.head_block; 386 } 387 388 journal->j_tail = 0; 389 return err; 390} 391 392static inline unsigned long long read_tag_block(journal_t *journal, 393 journal_block_tag_t *tag) 394{ 395 unsigned long long block = be32_to_cpu(tag->t_blocknr); 396 if (jbd2_has_feature_64bit(journal)) 397 block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32; 398 return block; 399} 400 401/* 402 * calc_chksums calculates the checksums for the blocks described in the 403 * descriptor block. 404 */ 405static int calc_chksums(journal_t *journal, struct buffer_head *bh, 406 unsigned long *next_log_block, __u32 *crc32_sum) 407{ 408 int i, num_blks, err; 409 unsigned long io_block; 410 struct buffer_head *obh; 411 412 num_blks = count_tags(journal, bh); 413 /* Calculate checksum of the descriptor block. */ 414 *crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size); 415 416 for (i = 0; i < num_blks; i++) { 417 io_block = (*next_log_block)++; 418 wrap(journal, *next_log_block); 419 err = jread(&obh, journal, io_block); 420 if (err) { 421 printk(KERN_ERR "JBD2: IO error %d recovering block " 422 "%lu in log\n", err, io_block); 423 return 1; 424 } else { 425 *crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data, 426 obh->b_size); 427 } 428 put_bh(obh); 429 } 430 return 0; 431} 432 433static int jbd2_commit_block_csum_verify(journal_t *j, void *buf) 434{ 435 struct commit_header *h; 436 __be32 provided; 437 __u32 calculated; 438 439 if (!jbd2_journal_has_csum_v2or3(j)) 440 return 1; 441 442 h = buf; 443 provided = h->h_chksum[0]; 444 h->h_chksum[0] = 0; 445 calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize); 446 h->h_chksum[0] = provided; 447 448 return provided == cpu_to_be32(calculated); 449} 450 451static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag, 452 journal_block_tag3_t *tag3, 453 void *buf, __u32 sequence) 454{ 455 __u32 csum32; 456 __be32 seq; 457 458 if (!jbd2_journal_has_csum_v2or3(j)) 459 return 1; 460 461 seq = cpu_to_be32(sequence); 462 csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq)); 463 csum32 = jbd2_chksum(j, csum32, buf, j->j_blocksize); 464 465 if (jbd2_has_feature_csum3(j)) 466 return tag3->t_checksum == cpu_to_be32(csum32); 467 else 468 return tag->t_checksum == cpu_to_be16(csum32); 469} 470 471static int do_one_pass(journal_t *journal, 472 struct recovery_info *info, enum passtype pass) 473{ 474 unsigned int first_commit_ID, next_commit_ID; 475 unsigned long next_log_block, head_block; 476 int err, success = 0; 477 journal_superblock_t * sb; 478 journal_header_t * tmp; 479 struct buffer_head * bh; 480 unsigned int sequence; 481 int blocktype; 482 int tag_bytes = journal_tag_bytes(journal); 483 __u32 crc32_sum = ~0; /* Transactional Checksums */ 484 int descr_csum_size = 0; 485 int block_error = 0; 486 bool need_check_commit_time = false; 487 __u64 last_trans_commit_time = 0, commit_time; 488 489 /* 490 * First thing is to establish what we expect to find in the log 491 * (in terms of transaction IDs), and where (in terms of log 492 * block offsets): query the superblock. 493 */ 494 495 sb = journal->j_superblock; 496 next_commit_ID = be32_to_cpu(sb->s_sequence); 497 next_log_block = be32_to_cpu(sb->s_start); 498 head_block = next_log_block; 499 500 first_commit_ID = next_commit_ID; 501 if (pass == PASS_SCAN) 502 info->start_transaction = first_commit_ID; 503 504 jbd2_debug(1, "Starting recovery pass %d\n", pass); 505 506 /* 507 * Now we walk through the log, transaction by transaction, 508 * making sure that each transaction has a commit block in the 509 * expected place. Each complete transaction gets replayed back 510 * into the main filesystem. 511 */ 512 513 while (1) { 514 int flags; 515 char * tagp; 516 journal_block_tag_t tag; 517 struct buffer_head * obh; 518 struct buffer_head * nbh; 519 520 cond_resched(); 521 522 /* If we already know where to stop the log traversal, 523 * check right now that we haven't gone past the end of 524 * the log. */ 525 526 if (pass != PASS_SCAN) 527 if (tid_geq(next_commit_ID, info->end_transaction)) 528 break; 529 530 jbd2_debug(2, "Scanning for sequence ID %u at %lu/%lu\n", 531 next_commit_ID, next_log_block, journal->j_last); 532 533 /* Skip over each chunk of the transaction looking 534 * either the next descriptor block or the final commit 535 * record. */ 536 537 jbd2_debug(3, "JBD2: checking block %ld\n", next_log_block); 538 err = jread(&bh, journal, next_log_block); 539 if (err) 540 goto failed; 541 542 next_log_block++; 543 wrap(journal, next_log_block); 544 545 /* What kind of buffer is it? 546 * 547 * If it is a descriptor block, check that it has the 548 * expected sequence number. Otherwise, we're all done 549 * here. */ 550 551 tmp = (journal_header_t *)bh->b_data; 552 553 if (tmp->h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER)) { 554 brelse(bh); 555 break; 556 } 557 558 blocktype = be32_to_cpu(tmp->h_blocktype); 559 sequence = be32_to_cpu(tmp->h_sequence); 560 jbd2_debug(3, "Found magic %d, sequence %d\n", 561 blocktype, sequence); 562 563 if (sequence != next_commit_ID) { 564 brelse(bh); 565 break; 566 } 567 568 /* OK, we have a valid descriptor block which matches 569 * all of the sequence number checks. What are we going 570 * to do with it? That depends on the pass... */ 571 572 switch(blocktype) { 573 case JBD2_DESCRIPTOR_BLOCK: 574 /* Verify checksum first */ 575 if (jbd2_journal_has_csum_v2or3(journal)) 576 descr_csum_size = 577 sizeof(struct jbd2_journal_block_tail); 578 if (descr_csum_size > 0 && 579 !jbd2_descriptor_block_csum_verify(journal, 580 bh->b_data)) { 581 /* 582 * PASS_SCAN can see stale blocks due to lazy 583 * journal init. Don't error out on those yet. 584 */ 585 if (pass != PASS_SCAN) { 586 pr_err("JBD2: Invalid checksum recovering block %lu in log\n", 587 next_log_block); 588 err = -EFSBADCRC; 589 brelse(bh); 590 goto failed; 591 } 592 need_check_commit_time = true; 593 jbd2_debug(1, 594 "invalid descriptor block found in %lu\n", 595 next_log_block); 596 } 597 598 /* If it is a valid descriptor block, replay it 599 * in pass REPLAY; if journal_checksums enabled, then 600 * calculate checksums in PASS_SCAN, otherwise, 601 * just skip over the blocks it describes. */ 602 if (pass != PASS_REPLAY) { 603 if (pass == PASS_SCAN && 604 jbd2_has_feature_checksum(journal) && 605 !need_check_commit_time && 606 !info->end_transaction) { 607 if (calc_chksums(journal, bh, 608 &next_log_block, 609 &crc32_sum)) { 610 put_bh(bh); 611 break; 612 } 613 put_bh(bh); 614 continue; 615 } 616 next_log_block += count_tags(journal, bh); 617 wrap(journal, next_log_block); 618 put_bh(bh); 619 continue; 620 } 621 622 /* A descriptor block: we can now write all of 623 * the data blocks. Yay, useful work is finally 624 * getting done here! */ 625 626 tagp = &bh->b_data[sizeof(journal_header_t)]; 627 while ((tagp - bh->b_data + tag_bytes) 628 <= journal->j_blocksize - descr_csum_size) { 629 unsigned long io_block; 630 631 memcpy(&tag, tagp, sizeof(tag)); 632 flags = be16_to_cpu(tag.t_flags); 633 634 io_block = next_log_block++; 635 wrap(journal, next_log_block); 636 err = jread(&obh, journal, io_block); 637 if (err) { 638 /* Recover what we can, but 639 * report failure at the end. */ 640 success = err; 641 printk(KERN_ERR 642 "JBD2: IO error %d recovering " 643 "block %ld in log\n", 644 err, io_block); 645 } else { 646 unsigned long long blocknr; 647 648 J_ASSERT(obh != NULL); 649 blocknr = read_tag_block(journal, 650 &tag); 651 652 /* If the block has been 653 * revoked, then we're all done 654 * here. */ 655 if (jbd2_journal_test_revoke 656 (journal, blocknr, 657 next_commit_ID)) { 658 brelse(obh); 659 ++info->nr_revoke_hits; 660 goto skip_write; 661 } 662 663 /* Look for block corruption */ 664 if (!jbd2_block_tag_csum_verify( 665 journal, &tag, (journal_block_tag3_t *)tagp, 666 obh->b_data, be32_to_cpu(tmp->h_sequence))) { 667 brelse(obh); 668 success = -EFSBADCRC; 669 printk(KERN_ERR "JBD2: Invalid " 670 "checksum recovering " 671 "data block %llu in " 672 "log\n", blocknr); 673 block_error = 1; 674 goto skip_write; 675 } 676 677 /* Find a buffer for the new 678 * data being restored */ 679 nbh = __getblk(journal->j_fs_dev, 680 blocknr, 681 journal->j_blocksize); 682 if (nbh == NULL) { 683 printk(KERN_ERR 684 "JBD2: Out of memory " 685 "during recovery.\n"); 686 err = -ENOMEM; 687 brelse(bh); 688 brelse(obh); 689 goto failed; 690 } 691 692 lock_buffer(nbh); 693 memcpy(nbh->b_data, obh->b_data, 694 journal->j_blocksize); 695 if (flags & JBD2_FLAG_ESCAPE) { 696 *((__be32 *)nbh->b_data) = 697 cpu_to_be32(JBD2_MAGIC_NUMBER); 698 } 699 700 BUFFER_TRACE(nbh, "marking dirty"); 701 set_buffer_uptodate(nbh); 702 mark_buffer_dirty(nbh); 703 BUFFER_TRACE(nbh, "marking uptodate"); 704 ++info->nr_replays; 705 unlock_buffer(nbh); 706 brelse(obh); 707 brelse(nbh); 708 } 709 710 skip_write: 711 tagp += tag_bytes; 712 if (!(flags & JBD2_FLAG_SAME_UUID)) 713 tagp += 16; 714 715 if (flags & JBD2_FLAG_LAST_TAG) 716 break; 717 } 718 719 brelse(bh); 720 continue; 721 722 case JBD2_COMMIT_BLOCK: 723 /* How to differentiate between interrupted commit 724 * and journal corruption ? 725 * 726 * {nth transaction} 727 * Checksum Verification Failed 728 * | 729 * ____________________ 730 * | | 731 * async_commit sync_commit 732 * | | 733 * | GO TO NEXT "Journal Corruption" 734 * | TRANSACTION 735 * | 736 * {(n+1)th transanction} 737 * | 738 * _______|______________ 739 * | | 740 * Commit block found Commit block not found 741 * | | 742 * "Journal Corruption" | 743 * _____________|_________ 744 * | | 745 * nth trans corrupt OR nth trans 746 * and (n+1)th interrupted interrupted 747 * before commit block 748 * could reach the disk. 749 * (Cannot find the difference in above 750 * mentioned conditions. Hence assume 751 * "Interrupted Commit".) 752 */ 753 commit_time = be64_to_cpu( 754 ((struct commit_header *)bh->b_data)->h_commit_sec); 755 /* 756 * If need_check_commit_time is set, it means we are in 757 * PASS_SCAN and csum verify failed before. If 758 * commit_time is increasing, it's the same journal, 759 * otherwise it is stale journal block, just end this 760 * recovery. 761 */ 762 if (need_check_commit_time) { 763 if (commit_time >= last_trans_commit_time) { 764 pr_err("JBD2: Invalid checksum found in transaction %u\n", 765 next_commit_ID); 766 err = -EFSBADCRC; 767 brelse(bh); 768 goto failed; 769 } 770 ignore_crc_mismatch: 771 /* 772 * It likely does not belong to same journal, 773 * just end this recovery with success. 774 */ 775 jbd2_debug(1, "JBD2: Invalid checksum ignored in transaction %u, likely stale data\n", 776 next_commit_ID); 777 brelse(bh); 778 goto done; 779 } 780 781 /* 782 * Found an expected commit block: if checksums 783 * are present, verify them in PASS_SCAN; else not 784 * much to do other than move on to the next sequence 785 * number. 786 */ 787 if (pass == PASS_SCAN && 788 jbd2_has_feature_checksum(journal)) { 789 struct commit_header *cbh = 790 (struct commit_header *)bh->b_data; 791 unsigned found_chksum = 792 be32_to_cpu(cbh->h_chksum[0]); 793 794 if (info->end_transaction) { 795 journal->j_failed_commit = 796 info->end_transaction; 797 brelse(bh); 798 break; 799 } 800 801 /* Neither checksum match nor unused? */ 802 if (!((crc32_sum == found_chksum && 803 cbh->h_chksum_type == 804 JBD2_CRC32_CHKSUM && 805 cbh->h_chksum_size == 806 JBD2_CRC32_CHKSUM_SIZE) || 807 (cbh->h_chksum_type == 0 && 808 cbh->h_chksum_size == 0 && 809 found_chksum == 0))) 810 goto chksum_error; 811 812 crc32_sum = ~0; 813 } 814 if (pass == PASS_SCAN && 815 !jbd2_commit_block_csum_verify(journal, 816 bh->b_data)) { 817 chksum_error: 818 if (commit_time < last_trans_commit_time) 819 goto ignore_crc_mismatch; 820 info->end_transaction = next_commit_ID; 821 info->head_block = head_block; 822 823 if (!jbd2_has_feature_async_commit(journal)) { 824 journal->j_failed_commit = 825 next_commit_ID; 826 brelse(bh); 827 break; 828 } 829 } 830 if (pass == PASS_SCAN) { 831 last_trans_commit_time = commit_time; 832 head_block = next_log_block; 833 } 834 brelse(bh); 835 next_commit_ID++; 836 continue; 837 838 case JBD2_REVOKE_BLOCK: 839 /* 840 * Check revoke block crc in pass_scan, if csum verify 841 * failed, check commit block time later. 842 */ 843 if (pass == PASS_SCAN && 844 !jbd2_descriptor_block_csum_verify(journal, 845 bh->b_data)) { 846 jbd2_debug(1, "JBD2: invalid revoke block found in %lu\n", 847 next_log_block); 848 need_check_commit_time = true; 849 } 850 /* If we aren't in the REVOKE pass, then we can 851 * just skip over this block. */ 852 if (pass != PASS_REVOKE) { 853 brelse(bh); 854 continue; 855 } 856 857 err = scan_revoke_records(journal, bh, 858 next_commit_ID, info); 859 brelse(bh); 860 if (err) 861 goto failed; 862 continue; 863 864 default: 865 jbd2_debug(3, "Unrecognised magic %d, end of scan.\n", 866 blocktype); 867 brelse(bh); 868 goto done; 869 } 870 } 871 872 done: 873 /* 874 * We broke out of the log scan loop: either we came to the 875 * known end of the log or we found an unexpected block in the 876 * log. If the latter happened, then we know that the "current" 877 * transaction marks the end of the valid log. 878 */ 879 880 if (pass == PASS_SCAN) { 881 if (!info->end_transaction) 882 info->end_transaction = next_commit_ID; 883 if (!info->head_block) 884 info->head_block = head_block; 885 } else { 886 /* It's really bad news if different passes end up at 887 * different places (but possible due to IO errors). */ 888 if (info->end_transaction != next_commit_ID) { 889 printk(KERN_ERR "JBD2: recovery pass %d ended at " 890 "transaction %u, expected %u\n", 891 pass, next_commit_ID, info->end_transaction); 892 if (!success) 893 success = -EIO; 894 } 895 } 896 897 if (jbd2_has_feature_fast_commit(journal) && pass != PASS_REVOKE) { 898 err = fc_do_one_pass(journal, info, pass); 899 if (err) 900 success = err; 901 } 902 903 if (block_error && success == 0) 904 success = -EIO; 905 return success; 906 907 failed: 908 return err; 909} 910 911/* Scan a revoke record, marking all blocks mentioned as revoked. */ 912 913static int scan_revoke_records(journal_t *journal, struct buffer_head *bh, 914 tid_t sequence, struct recovery_info *info) 915{ 916 jbd2_journal_revoke_header_t *header; 917 int offset, max; 918 unsigned csum_size = 0; 919 __u32 rcount; 920 int record_len = 4; 921 922 header = (jbd2_journal_revoke_header_t *) bh->b_data; 923 offset = sizeof(jbd2_journal_revoke_header_t); 924 rcount = be32_to_cpu(header->r_count); 925 926 if (jbd2_journal_has_csum_v2or3(journal)) 927 csum_size = sizeof(struct jbd2_journal_block_tail); 928 if (rcount > journal->j_blocksize - csum_size) 929 return -EINVAL; 930 max = rcount; 931 932 if (jbd2_has_feature_64bit(journal)) 933 record_len = 8; 934 935 while (offset + record_len <= max) { 936 unsigned long long blocknr; 937 int err; 938 939 if (record_len == 4) 940 blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset))); 941 else 942 blocknr = be64_to_cpu(* ((__be64 *) (bh->b_data+offset))); 943 offset += record_len; 944 err = jbd2_journal_set_revoke(journal, blocknr, sequence); 945 if (err) 946 return err; 947 ++info->nr_revokes; 948 } 949 return 0; 950} 951