]>
git.ipfire.org Git - thirdparty/e2fsprogs.git/blob - e2fsck/recovery.c
2 * linux/fs/jbd2/recovery.c
4 * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
6 * Copyright 1999-2000 Red Hat Software --- All Rights Reserved
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.
12 * Journal recovery routines for the generic filesystem journaling code;
13 * part of the ext2fs journaling system.
19 #include <linux/time.h>
21 #include <linux/jbd2.h>
22 #include <linux/errno.h>
23 #include <linux/crc32.h>
24 #include <linux/blkdev.h>
28 * Maintain information about the progress of the recovery job, so that
29 * the different passes can carry information between them.
33 tid_t start_transaction
;
34 tid_t end_transaction
;
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
*);
49 /* Release readahead buffers after use */
50 static void journal_brelse_array(struct buffer_head
*b
[], int n
)
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.
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
70 static int do_readahead(journal_t
*journal
, unsigned int start
)
73 unsigned int max
, nbufs
, next
;
74 unsigned long long blocknr
;
75 struct buffer_head
*bh
;
77 struct buffer_head
* bufs
[MAXBUF
];
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
;
84 /* Do the readahead itself. We'll submit MAXBUF buffer_heads at
85 * a time to the block device IO layer. */
89 for (next
= start
; next
< max
; next
++) {
90 err
= journal_bmap(journal
, next
, &blocknr
);
93 printk(KERN_ERR
"JBD2: bad block at offset %u\n",
98 bh
= __getblk(journal
->j_dev
, blocknr
, journal
->j_blocksize
);
104 if (!buffer_uptodate(bh
) && !buffer_locked(bh
)) {
106 if (nbufs
== MAXBUF
) {
107 ll_rw_block(READ
, nbufs
, bufs
);
108 journal_brelse_array(bufs
, nbufs
);
116 ll_rw_block(READ
, nbufs
, bufs
);
121 journal_brelse_array(bufs
, nbufs
);
125 #endif /* __KERNEL__ */
127 static inline __u32
get_be32(__be32
*p
)
129 unsigned char *cp
= (unsigned char *) p
;
133 ret
= (ret
<< 8) + *cp
++;
134 ret
= (ret
<< 8) + *cp
++;
135 ret
= (ret
<< 8) + *cp
++;
139 static inline __u16
get_be16(__be16
*p
)
141 unsigned char *cp
= (unsigned char *) p
;
145 ret
= (ret
<< 8) + *cp
++;
150 * Read a block from the journal
153 static int jread(struct buffer_head
**bhp
, journal_t
*journal
,
157 unsigned long long blocknr
;
158 struct buffer_head
*bh
;
162 if (offset
>= journal
->j_maxlen
) {
163 printk(KERN_ERR
"JBD2: corrupted journal superblock\n");
164 return -EFSCORRUPTED
;
167 err
= journal_bmap(journal
, offset
, &blocknr
);
170 printk(KERN_ERR
"JBD2: bad block at offset %u\n",
175 bh
= __getblk(journal
->j_dev
, blocknr
, journal
->j_blocksize
);
179 if (!buffer_uptodate(bh
)) {
180 /* If this is a brand new buffer, start readahead.
181 Otherwise, we assume we are already reading it. */
183 do_readahead(journal
, offset
);
187 if (!buffer_uptodate(bh
)) {
188 printk(KERN_ERR
"JBD2: Failed to read block at offset %u\n",
198 static int jbd2_descr_block_csum_verify(journal_t
*j
,
201 struct journal_block_tail
*tail
;
205 if (!journal_has_csum_v2or3(j
))
208 tail
= (struct journal_block_tail
*)((char *)buf
+ j
->j_blocksize
-
209 sizeof(struct journal_block_tail
));
210 provided
= tail
->t_checksum
;
211 tail
->t_checksum
= 0;
212 calculated
= jbd2_chksum(j
, j
->j_csum_seed
, buf
, j
->j_blocksize
);
213 tail
->t_checksum
= provided
;
215 return provided
== ext2fs_cpu_to_be32(calculated
);
219 * Count the number of in-use tags in a journal descriptor block.
222 static int count_tags(journal_t
*journal
, struct buffer_head
*bh
)
225 journal_block_tag_t
* tag
;
226 int nr
= 0, size
= journal
->j_blocksize
;
227 int tag_bytes
= journal_tag_bytes(journal
);
229 if (journal_has_csum_v2or3(journal
))
230 size
-= sizeof(struct journal_block_tail
);
232 tagp
= &bh
->b_data
[sizeof(journal_header_t
)];
234 while ((tagp
- bh
->b_data
+ tag_bytes
) <= size
) {
235 tag
= (journal_block_tag_t
*) tagp
;
239 if (!(get_be16(&tag
->t_flags
) & JFS_FLAG_SAME_UUID
))
242 if (get_be16(&tag
->t_flags
) & JFS_FLAG_LAST_TAG
)
250 /* Make sure we wrap around the log correctly! */
251 #define wrap(journal, var) \
253 if (var >= (journal)->j_last) \
254 var -= ((journal)->j_last - (journal)->j_first); \
258 * journal_recover - recovers a on-disk journal
259 * @journal: the journal to recover
261 * The primary function for recovering the log contents when mounting a
264 * Recovery is done in three passes. In the first pass, we look for the
265 * end of the log. In the second, we assemble the list of revoke
266 * blocks. In the third and final pass, we replay any un-revoked blocks
269 int journal_recover(journal_t
*journal
)
272 journal_superblock_t
* sb
;
274 struct recovery_info info
;
276 memset(&info
, 0, sizeof(info
));
277 sb
= journal
->j_superblock
;
280 * The journal superblock's s_start field (the current log head)
281 * is always zero if, and only if, the journal was cleanly
286 jbd_debug(1, "No recovery required, last transaction %d\n",
287 ext2fs_be32_to_cpu(sb
->s_sequence
));
288 journal
->j_transaction_sequence
= ext2fs_be32_to_cpu(sb
->s_sequence
) + 1;
292 err
= do_one_pass(journal
, &info
, PASS_SCAN
);
294 err
= do_one_pass(journal
, &info
, PASS_REVOKE
);
296 err
= do_one_pass(journal
, &info
, PASS_REPLAY
);
298 jbd_debug(1, "JBD2: recovery, exit status %d, "
299 "recovered transactions %u to %u\n",
300 err
, info
.start_transaction
, info
.end_transaction
);
301 jbd_debug(1, "JBD2: Replayed %d and revoked %d/%d blocks\n",
302 info
.nr_replays
, info
.nr_revoke_hits
, info
.nr_revokes
);
304 /* Restart the log at the next transaction ID, thus invalidating
305 * any existing commit records in the log. */
306 journal
->j_transaction_sequence
= ++info
.end_transaction
;
308 journal_clear_revoke(journal
);
309 err2
= sync_blockdev(journal
->j_fs_dev
);
312 /* Make sure all replayed data is on permanent storage */
313 if (journal
->j_flags
& JFS_BARRIER
) {
314 err2
= blkdev_issue_flush(journal
->j_fs_dev
, GFP_KERNEL
, NULL
);
322 * journal_skip_recovery - Start journal and wipe exiting records
323 * @journal: journal to startup
325 * Locate any valid recovery information from the journal and set up the
326 * journal structures in memory to ignore it (presumably because the
327 * caller has evidence that it is out of date).
328 * This function doesn't appear to be exported..
330 * We perform one pass over the journal to allow us to tell the user how
331 * much recovery information is being erased, and to let us initialise
332 * the journal transaction sequence numbers to the next unused ID.
334 int journal_skip_recovery(journal_t
*journal
)
338 struct recovery_info info
;
340 memset (&info
, 0, sizeof(info
));
342 err
= do_one_pass(journal
, &info
, PASS_SCAN
);
345 printk(KERN_ERR
"JBD2: error %d scanning journal\n", err
);
346 ++journal
->j_transaction_sequence
;
348 #ifdef CONFIG_JFS_DEBUG
349 int dropped
= info
.end_transaction
-
350 ext2fs_be32_to_cpu(journal
->j_superblock
->s_sequence
);
352 "JBD2: ignoring %d transaction%s from the journal.\n",
353 dropped
, (dropped
== 1) ? "" : "s");
355 journal
->j_transaction_sequence
= ++info
.end_transaction
;
362 static inline unsigned long long read_tag_block(journal_t
*journal
,
363 journal_block_tag_t
*tag
)
365 unsigned long long block
= get_be32(&tag
->t_blocknr
);
366 if (jfs_has_feature_64bit(journal
))
367 block
|= (u64
)get_be32(&tag
->t_blocknr_high
) << 32;
372 * calc_chksums calculates the checksums for the blocks described in the
375 static int calc_chksums(journal_t
*journal
, struct buffer_head
*bh
,
376 unsigned long *next_log_block
, __u32
*crc32_sum
)
378 int i
, num_blks
, err
;
379 unsigned long io_block
;
380 struct buffer_head
*obh
;
382 num_blks
= count_tags(journal
, bh
);
383 /* Calculate checksum of the descriptor block. */
384 *crc32_sum
= crc32_be(*crc32_sum
, (void *)bh
->b_data
, bh
->b_size
);
386 for (i
= 0; i
< num_blks
; i
++) {
387 io_block
= (*next_log_block
)++;
388 wrap(journal
, *next_log_block
);
389 err
= jread(&obh
, journal
, io_block
);
391 printk(KERN_ERR
"JBD2: IO error %d recovering block "
392 "%lu in log\n", err
, io_block
);
395 *crc32_sum
= crc32_be(*crc32_sum
, (void *)obh
->b_data
,
403 static int jbd2_commit_block_csum_verify(journal_t
*j
, void *buf
)
405 struct commit_header
*h
;
409 if (!journal_has_csum_v2or3(j
))
413 provided
= h
->h_chksum
[0];
415 calculated
= jbd2_chksum(j
, j
->j_csum_seed
, buf
, j
->j_blocksize
);
416 h
->h_chksum
[0] = provided
;
418 return provided
== ext2fs_cpu_to_be32(calculated
);
421 static int jbd2_block_tag_csum_verify(journal_t
*j
, journal_block_tag_t
*tag
,
422 void *buf
, __u32 sequence
)
424 journal_block_tag3_t
*tag3
= (journal_block_tag3_t
*)tag
;
428 if (!journal_has_csum_v2or3(j
))
431 seq
= ext2fs_cpu_to_be32(sequence
);
432 csum32
= jbd2_chksum(j
, j
->j_csum_seed
, (__u8
*)&seq
, sizeof(seq
));
433 csum32
= jbd2_chksum(j
, csum32
, buf
, j
->j_blocksize
);
435 if (jfs_has_feature_csum3(j
))
436 return get_be32(&tag3
->t_checksum
) == csum32
;
438 return get_be16(&tag
->t_checksum
) == (csum32
& 0xFFFF);
441 static int do_one_pass(journal_t
*journal
,
442 struct recovery_info
*info
, enum passtype pass
)
444 unsigned int first_commit_ID
, next_commit_ID
;
445 unsigned long next_log_block
;
446 int err
, success
= 0;
447 journal_superblock_t
* sb
;
448 journal_header_t
* tmp
;
449 struct buffer_head
* bh
;
450 unsigned int sequence
;
452 int tag_bytes
= journal_tag_bytes(journal
);
453 __u32 crc32_sum
= ~0; /* Transactional Checksums */
454 int descr_csum_size
= 0;
458 * First thing is to establish what we expect to find in the log
459 * (in terms of transaction IDs), and where (in terms of log
460 * block offsets): query the superblock.
463 sb
= journal
->j_superblock
;
464 next_commit_ID
= ext2fs_be32_to_cpu(sb
->s_sequence
);
465 next_log_block
= ext2fs_be32_to_cpu(sb
->s_start
);
467 first_commit_ID
= next_commit_ID
;
468 if (pass
== PASS_SCAN
)
469 info
->start_transaction
= first_commit_ID
;
471 jbd_debug(1, "Starting recovery pass %d\n", pass
);
474 * Now we walk through the log, transaction by transaction,
475 * making sure that each transaction has a commit block in the
476 * expected place. Each complete transaction gets replayed back
477 * into the main filesystem.
483 journal_block_tag_t
* tag
;
484 struct buffer_head
* obh
;
485 struct buffer_head
* nbh
;
489 /* If we already know where to stop the log traversal,
490 * check right now that we haven't gone past the end of
493 if (pass
!= PASS_SCAN
)
494 if (tid_geq(next_commit_ID
, info
->end_transaction
))
497 jbd_debug(2, "Scanning for sequence ID %u at %lu/%lu\n",
498 next_commit_ID
, next_log_block
, journal
->j_last
);
500 /* Skip over each chunk of the transaction looking
501 * either the next descriptor block or the final commit
504 jbd_debug(3, "JBD2: checking block %ld\n", next_log_block
);
505 err
= jread(&bh
, journal
, next_log_block
);
510 wrap(journal
, next_log_block
);
512 /* What kind of buffer is it?
514 * If it is a descriptor block, check that it has the
515 * expected sequence number. Otherwise, we're all done
518 tmp
= (journal_header_t
*)bh
->b_data
;
520 if (tmp
->h_magic
!= ext2fs_cpu_to_be32(JFS_MAGIC_NUMBER
)) {
525 blocktype
= ext2fs_be32_to_cpu(tmp
->h_blocktype
);
526 sequence
= ext2fs_be32_to_cpu(tmp
->h_sequence
);
527 jbd_debug(3, "Found magic %d, sequence %d\n",
528 blocktype
, sequence
);
530 if (sequence
!= next_commit_ID
) {
535 /* OK, we have a valid descriptor block which matches
536 * all of the sequence number checks. What are we going
537 * to do with it? That depends on the pass... */
540 case JFS_DESCRIPTOR_BLOCK
:
541 /* Verify checksum first */
542 if (journal_has_csum_v2or3(journal
))
544 sizeof(struct journal_block_tail
);
545 if (descr_csum_size
> 0 &&
546 !jbd2_descr_block_csum_verify(journal
,
553 /* If it is a valid descriptor block, replay it
554 * in pass REPLAY; if journal_checksums enabled, then
555 * calculate checksums in PASS_SCAN, otherwise,
556 * just skip over the blocks it describes. */
557 if (pass
!= PASS_REPLAY
) {
558 if (pass
== PASS_SCAN
&&
559 jfs_has_feature_checksum(journal
) &&
560 !info
->end_transaction
) {
561 if (calc_chksums(journal
, bh
,
570 next_log_block
+= count_tags(journal
, bh
);
571 wrap(journal
, next_log_block
);
576 /* A descriptor block: we can now write all of
577 * the data blocks. Yay, useful work is finally
578 * getting done here! */
580 tagp
= &bh
->b_data
[sizeof(journal_header_t
)];
581 while ((tagp
- bh
->b_data
+ tag_bytes
)
582 <= journal
->j_blocksize
- descr_csum_size
) {
583 unsigned long io_block
;
585 tag
= (journal_block_tag_t
*) tagp
;
586 flags
= get_be16(&tag
->t_flags
);
588 io_block
= next_log_block
++;
589 wrap(journal
, next_log_block
);
590 err
= jread(&obh
, journal
, io_block
);
592 /* Recover what we can, but
593 * report failure at the end. */
596 "JBD2: IO error %d recovering "
597 "block %ld in log\n",
600 unsigned long long blocknr
;
602 J_ASSERT(obh
!= NULL
);
603 blocknr
= read_tag_block(journal
,
606 /* If the block has been
607 * revoked, then we're all done
609 if (journal_test_revoke
613 ++info
->nr_revoke_hits
;
617 /* Look for block corruption */
618 if (!jbd2_block_tag_csum_verify(
619 journal
, tag
, obh
->b_data
,
620 ext2fs_be32_to_cpu(tmp
->h_sequence
))) {
622 success
= -EFSBADCRC
;
623 printk(KERN_ERR
"JBD2: Invalid "
624 "checksum recovering "
625 "block %llu in log\n",
631 /* Find a buffer for the new
632 * data being restored */
633 nbh
= __getblk(journal
->j_fs_dev
,
635 journal
->j_blocksize
);
638 "JBD2: Out of memory "
639 "during recovery.\n");
647 memcpy(nbh
->b_data
, obh
->b_data
,
648 journal
->j_blocksize
);
649 if (flags
& JFS_FLAG_ESCAPE
) {
650 __u32 magic
= ext2fs_cpu_to_be32(JFS_MAGIC_NUMBER
);
651 memcpy(nbh
->b_data
, &magic
,
655 BUFFER_TRACE(nbh
, "marking dirty");
656 set_buffer_uptodate(nbh
);
657 mark_buffer_dirty(nbh
);
658 BUFFER_TRACE(nbh
, "marking uptodate");
660 /* ll_rw_block(WRITE, 1, &nbh); */
668 if (!(flags
& JFS_FLAG_SAME_UUID
))
671 if (flags
& JFS_FLAG_LAST_TAG
)
678 case JFS_COMMIT_BLOCK
:
679 /* How to differentiate between interrupted commit
680 * and journal corruption ?
683 * Checksum Verification Failed
685 * ____________________
687 * async_commit sync_commit
689 * | GO TO NEXT "Journal Corruption"
692 * {(n+1)th transaction}
694 * _______|______________
696 * Commit block found Commit block not found
698 * "Journal Corruption" |
699 * _____________|_________
701 * nth trans corrupt OR nth trans
702 * and (n+1)th interrupted interrupted
703 * before commit block
704 * could reach the disk.
705 * (Cannot find the difference in above
706 * mentioned conditions. Hence assume
707 * "Interrupted Commit".)
710 /* Found an expected commit block: if checksums
711 * are present verify them in PASS_SCAN; else not
712 * much to do other than move on to the next sequence
714 if (pass
== PASS_SCAN
&&
715 jfs_has_feature_checksum(journal
)) {
716 int chksum_err
, chksum_seen
;
717 struct commit_header
*cbh
=
718 (struct commit_header
*)bh
->b_data
;
719 unsigned found_chksum
=
720 ext2fs_be32_to_cpu(cbh
->h_chksum
[0]);
722 chksum_err
= chksum_seen
= 0;
724 if (info
->end_transaction
) {
725 journal
->j_failed_commit
=
726 info
->end_transaction
;
731 if (crc32_sum
== found_chksum
&&
732 cbh
->h_chksum_type
== JFS_CRC32_CHKSUM
&&
733 cbh
->h_chksum_size
==
734 JFS_CRC32_CHKSUM_SIZE
)
736 else if (!(cbh
->h_chksum_type
== 0 &&
737 cbh
->h_chksum_size
== 0 &&
741 * If fs is mounted using an old kernel and then
742 * kernel with journal_chksum is used then we
743 * get a situation where the journal flag has
744 * checksum flag set but checksums are not
745 * present i.e chksum = 0, in the individual
747 * Hence to avoid checksum failures, in this
748 * situation, this extra check is added.
753 info
->end_transaction
= next_commit_ID
;
755 if (!jfs_has_feature_async_commit(journal
)){
756 journal
->j_failed_commit
=
764 if (pass
== PASS_SCAN
&&
765 !jbd2_commit_block_csum_verify(journal
,
767 info
->end_transaction
= next_commit_ID
;
769 if (!jfs_has_feature_async_commit(journal
)) {
770 journal
->j_failed_commit
=
780 case JFS_REVOKE_BLOCK
:
781 /* If we aren't in the REVOKE pass, then we can
782 * just skip over this block. */
783 if (pass
!= PASS_REVOKE
) {
788 err
= scan_revoke_records(journal
, bh
,
789 next_commit_ID
, info
);
796 jbd_debug(3, "Unrecognised magic %d, end of scan.\n",
805 * We broke out of the log scan loop: either we came to the
806 * known end of the log or we found an unexpected block in the
807 * log. If the latter happened, then we know that the "current"
808 * transaction marks the end of the valid log.
811 if (pass
== PASS_SCAN
) {
812 if (!info
->end_transaction
)
813 info
->end_transaction
= next_commit_ID
;
815 /* It's really bad news if different passes end up at
816 * different places (but possible due to IO errors). */
817 if (info
->end_transaction
!= next_commit_ID
) {
818 printk(KERN_ERR
"JBD2: recovery pass %d ended at "
819 "transaction %u, expected %u\n",
820 pass
, next_commit_ID
, info
->end_transaction
);
825 if (block_error
&& success
== 0)
833 static int jbd2_revoke_block_csum_verify(journal_t
*j
,
836 struct journal_revoke_tail
*tail
;
840 if (!journal_has_csum_v2or3(j
))
843 tail
= (struct journal_revoke_tail
*)((char *)buf
+ j
->j_blocksize
-
844 sizeof(struct journal_revoke_tail
));
845 provided
= tail
->r_checksum
;
846 tail
->r_checksum
= 0;
847 calculated
= jbd2_chksum(j
, j
->j_csum_seed
, buf
, j
->j_blocksize
);
848 tail
->r_checksum
= provided
;
850 return provided
== ext2fs_cpu_to_be32(calculated
);
853 /* Scan a revoke record, marking all blocks mentioned as revoked. */
855 static int scan_revoke_records(journal_t
*journal
, struct buffer_head
*bh
,
856 tid_t sequence
, struct recovery_info
*info
)
858 journal_revoke_header_t
*header
;
860 unsigned csum_size
= 0;
864 header
= (journal_revoke_header_t
*) bh
->b_data
;
865 offset
= sizeof(journal_revoke_header_t
);
866 rcount
= ext2fs_be32_to_cpu(header
->r_count
);
868 if (!jbd2_revoke_block_csum_verify(journal
, header
))
871 if (journal_has_csum_v2or3(journal
))
872 csum_size
= sizeof(struct journal_revoke_tail
);
873 if (rcount
> journal
->j_blocksize
- csum_size
)
877 if (jfs_has_feature_64bit(journal
))
880 while (offset
+ record_len
<= max
) {
881 unsigned long long blocknr
;
885 blocknr
= ext2fs_be32_to_cpu(* ((__u32
*) (bh
->b_data
+offset
)));
887 blocknr
= ext2fs_be64_to_cpu(* ((__u64
*) (bh
->b_data
+offset
)));
888 offset
+= record_len
;
889 err
= journal_set_revoke(journal
, blocknr
, sequence
);