?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
powerpc/kprobes: Remove kretprobe_trampoline_holder.
[linux/fpc-iii.git] / fs / jbd2 / recovery.c
blob805bc6bcd8abb0a6484ef1e808be98bbd51a6295
1 /*
2 * linux/fs/jbd2/recovery.c
3 *
4 * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
5 *
6 * Copyright 1999-2000 Red Hat Software --- All Rights Reserved
7 *
8 * This file is part of the Linux kernel and is made available under
9 * the terms of the GNU General Public License, version 2, or at your
10 * option, any later version, incorporated herein by reference.
11 *
12 * Journal recovery routines for the generic filesystem journaling code;
13 * part of the ext2fs journaling system.
14 */
15
16 #ifndef __KERNEL__
17 #include "jfs_user.h"
18 #else
19 #include <linux/time.h>
20 #include <linux/fs.h>
21 #include <linux/jbd2.h>
22 #include <linux/errno.h>
23 #include <linux/crc32.h>
24 #include <linux/blkdev.h>
25 #endif
26
27 /*
28 * Maintain information about the progress of the recovery job, so that
29 * the different passes can carry information between them.
30 */
31 struct recovery_info
32 {
33 tid_t start_transaction;
34 tid_t end_transaction;
35
36 int nr_replays;
37 int nr_revokes;
38 int nr_revoke_hits;
39 };
40
41 enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY};
42 static int do_one_pass(journal_t *journal,
43 struct recovery_info *info, enum passtype pass);
44 static int scan_revoke_records(journal_t *, struct buffer_head *,
45 tid_t, struct recovery_info *);
46
47 #ifdef __KERNEL__
48
49 /* Release readahead buffers after use */
50 static void journal_brelse_array(struct buffer_head *b[], int n)
51 {
52 while (--n >= 0)
53 brelse (b[n]);
54 }
55
56
57 /*
58 * When reading from the journal, we are going through the block device
59 * layer directly and so there is no readahead being done for us. We
60 * need to implement any readahead ourselves if we want it to happen at
61 * all. Recovery is basically one long sequential read, so make sure we
62 * do the IO in reasonably large chunks.
63 *
64 * This is not so critical that we need to be enormously clever about
65 * the readahead size, though. 128K is a purely arbitrary, good-enough
66 * fixed value.
67 */
68
69 #define MAXBUF 8
70 static int do_readahead(journal_t *journal, unsigned int start)
71 {
72 int err;
73 unsigned int max, nbufs, next;
74 unsigned long long blocknr;
75 struct buffer_head *bh;
76
77 struct buffer_head * bufs[MAXBUF];
78
79 /* Do up to 128K of readahead */
80 max = start + (128 * 1024 / journal->j_blocksize);
81 if (max > journal->j_maxlen)
82 max = journal->j_maxlen;
83
84 /* Do the readahead itself. We'll submit MAXBUF buffer_heads at
85 * a time to the block device IO layer. */
86
87 nbufs = 0;
88
89 for (next = start; next < max; next++) {
90 err = jbd2_journal_bmap(journal, next, &blocknr);
91
92 if (err) {
93 printk(KERN_ERR "JBD2: bad block at offset %u\n",
94 next);
95 goto failed;
96 }
97
98 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
99 if (!bh) {
100 err = -ENOMEM;
101 goto failed;
102 }
103
104 if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
105 bufs[nbufs++] = bh;
106 if (nbufs == MAXBUF) {
107 ll_rw_block(READ, nbufs, bufs);
108 journal_brelse_array(bufs, nbufs);
109 nbufs = 0;
110 }
111 } else
112 brelse(bh);
113 }
114
115 if (nbufs)
116 ll_rw_block(READ, nbufs, bufs);
117 err = 0;
118
119 failed:
120 if (nbufs)
121 journal_brelse_array(bufs, nbufs);
122 return err;
123 }
124
125 #endif /* __KERNEL__ */
126
127
128 /*
129 * Read a block from the journal
130 */
131
132 static int jread(struct buffer_head **bhp, journal_t *journal,
133 unsigned int offset)
134 {
135 int err;
136 unsigned long long blocknr;
137 struct buffer_head *bh;
138
139 *bhp = NULL;
140
141 if (offset >= journal->j_maxlen) {
142 printk(KERN_ERR "JBD2: corrupted journal superblock\n");
143 return -EFSCORRUPTED;
144 }
145
146 err = jbd2_journal_bmap(journal, offset, &blocknr);
147
148 if (err) {
149 printk(KERN_ERR "JBD2: bad block at offset %u\n",
150 offset);
151 return err;
152 }
153
154 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
155 if (!bh)
156 return -ENOMEM;
157
158 if (!buffer_uptodate(bh)) {
159 /* If this is a brand new buffer, start readahead.
160 Otherwise, we assume we are already reading it. */
161 if (!buffer_req(bh))
162 do_readahead(journal, offset);
163 wait_on_buffer(bh);
164 }
165
166 if (!buffer_uptodate(bh)) {
167 printk(KERN_ERR "JBD2: Failed to read block at offset %u\n",
168 offset);
169 brelse(bh);
170 return -EIO;
171 }
172
173 *bhp = bh;
174 return 0;
175 }
176
177 static int jbd2_descriptor_block_csum_verify(journal_t *j, void *buf)
178 {
179 struct jbd2_journal_block_tail *tail;
180 __be32 provided;
181 __u32 calculated;
182
183 if (!jbd2_journal_has_csum_v2or3(j))
184 return 1;
185
186 tail = (struct jbd2_journal_block_tail *)(buf + j->j_blocksize -
187 sizeof(struct jbd2_journal_block_tail));
188 provided = tail->t_checksum;
189 tail->t_checksum = 0;
190 calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
191 tail->t_checksum = provided;
192
193 return provided == cpu_to_be32(calculated);
194 }
195
196 /*
197 * Count the number of in-use tags in a journal descriptor block.
198 */
199
200 static int count_tags(journal_t *journal, struct buffer_head *bh)
201 {
202 char * tagp;
203 journal_block_tag_t * tag;
204 int nr = 0, size = journal->j_blocksize;
205 int tag_bytes = journal_tag_bytes(journal);
206
207 if (jbd2_journal_has_csum_v2or3(journal))
208 size -= sizeof(struct jbd2_journal_block_tail);
209
210 tagp = &bh->b_data[sizeof(journal_header_t)];
211
212 while ((tagp - bh->b_data + tag_bytes) <= size) {
213 tag = (journal_block_tag_t *) tagp;
214
215 nr++;
216 tagp += tag_bytes;
217 if (!(tag->t_flags & cpu_to_be16(JBD2_FLAG_SAME_UUID)))
218 tagp += 16;
219
220 if (tag->t_flags & cpu_to_be16(JBD2_FLAG_LAST_TAG))
221 break;
222 }
223
224 return nr;
225 }
226
227
228 /* Make sure we wrap around the log correctly! */
229 #define wrap(journal, var) \
230 do { \
231 if (var >= (journal)->j_last) \
232 var -= ((journal)->j_last - (journal)->j_first); \
233 } while (0)
234
235 /**
236 * jbd2_journal_recover - recovers a on-disk journal
237 * @journal: the journal to recover
238 *
239 * The primary function for recovering the log contents when mounting a
240 * journaled device.
241 *
242 * Recovery is done in three passes. In the first pass, we look for the
243 * end of the log. In the second, we assemble the list of revoke
244 * blocks. In the third and final pass, we replay any un-revoked blocks
245 * in the log.
246 */
247 int jbd2_journal_recover(journal_t *journal)
248 {
249 int err, err2;
250 journal_superblock_t * sb;
251
252 struct recovery_info info;
253
254 memset(&info, 0, sizeof(info));
255 sb = journal->j_superblock;
256
257 /*
258 * The journal superblock's s_start field (the current log head)
259 * is always zero if, and only if, the journal was cleanly
260 * unmounted.
261 */
262
263 if (!sb->s_start) {
264 jbd_debug(1, "No recovery required, last transaction %d\n",
265 be32_to_cpu(sb->s_sequence));
266 journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1;
267 return 0;
268 }
269
270 err = do_one_pass(journal, &info, PASS_SCAN);
271 if (!err)
272 err = do_one_pass(journal, &info, PASS_REVOKE);
273 if (!err)
274 err = do_one_pass(journal, &info, PASS_REPLAY);
275
276 jbd_debug(1, "JBD2: recovery, exit status %d, "
277 "recovered transactions %u to %u\n",
278 err, info.start_transaction, info.end_transaction);
279 jbd_debug(1, "JBD2: Replayed %d and revoked %d/%d blocks\n",
280 info.nr_replays, info.nr_revoke_hits, info.nr_revokes);
281
282 /* Restart the log at the next transaction ID, thus invalidating
283 * any existing commit records in the log. */
284 journal->j_transaction_sequence = ++info.end_transaction;
285
286 jbd2_journal_clear_revoke(journal);
287 err2 = sync_blockdev(journal->j_fs_dev);
288 if (!err)
289 err = err2;
290 /* Make sure all replayed data is on permanent storage */
291 if (journal->j_flags & JBD2_BARRIER) {
292 err2 = blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
293 if (!err)
294 err = err2;
295 }
296 return err;
297 }
298
299 /**
300 * jbd2_journal_skip_recovery - Start journal and wipe exiting records
301 * @journal: journal to startup
302 *
303 * Locate any valid recovery information from the journal and set up the
304 * journal structures in memory to ignore it (presumably because the
305 * caller has evidence that it is out of date).
306 * This function doesn't appear to be exported..
307 *
308 * We perform one pass over the journal to allow us to tell the user how
309 * much recovery information is being erased, and to let us initialise
310 * the journal transaction sequence numbers to the next unused ID.
311 */
312 int jbd2_journal_skip_recovery(journal_t *journal)
313 {
314 int err;
315
316 struct recovery_info info;
317
318 memset (&info, 0, sizeof(info));
319
320 err = do_one_pass(journal, &info, PASS_SCAN);
321
322 if (err) {
323 printk(KERN_ERR "JBD2: error %d scanning journal\n", err);
324 ++journal->j_transaction_sequence;
325 } else {
326 #ifdef CONFIG_JBD2_DEBUG
327 int dropped = info.end_transaction -
328 be32_to_cpu(journal->j_superblock->s_sequence);
329 jbd_debug(1,
330 "JBD2: ignoring %d transaction%s from the journal.\n",
331 dropped, (dropped == 1) ? "" : "s");
332 #endif
333 journal->j_transaction_sequence = ++info.end_transaction;
334 }
335
336 journal->j_tail = 0;
337 return err;
338 }
339
340 static inline unsigned long long read_tag_block(journal_t *journal,
341 journal_block_tag_t *tag)
342 {
343 unsigned long long block = be32_to_cpu(tag->t_blocknr);
344 if (jbd2_has_feature_64bit(journal))
345 block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32;
346 return block;
347 }
348
349 /*
350 * calc_chksums calculates the checksums for the blocks described in the
351 * descriptor block.
352 */
353 static int calc_chksums(journal_t *journal, struct buffer_head *bh,
354 unsigned long *next_log_block, __u32 *crc32_sum)
355 {
356 int i, num_blks, err;
357 unsigned long io_block;
358 struct buffer_head *obh;
359
360 num_blks = count_tags(journal, bh);
361 /* Calculate checksum of the descriptor block. */
362 *crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size);
363
364 for (i = 0; i < num_blks; i++) {
365 io_block = (*next_log_block)++;
366 wrap(journal, *next_log_block);
367 err = jread(&obh, journal, io_block);
368 if (err) {
369 printk(KERN_ERR "JBD2: IO error %d recovering block "
370 "%lu in log\n", err, io_block);
371 return 1;
372 } else {
373 *crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data,
374 obh->b_size);
375 }
376 put_bh(obh);
377 }
378 return 0;
379 }
380
381 static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
382 {
383 struct commit_header *h;
384 __be32 provided;
385 __u32 calculated;
386
387 if (!jbd2_journal_has_csum_v2or3(j))
388 return 1;
389
390 h = buf;
391 provided = h->h_chksum[0];
392 h->h_chksum[0] = 0;
393 calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
394 h->h_chksum[0] = provided;
395
396 return provided == cpu_to_be32(calculated);
397 }
398
399 static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
400 void *buf, __u32 sequence)
401 {
402 journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
403 __u32 csum32;
404 __be32 seq;
405
406 if (!jbd2_journal_has_csum_v2or3(j))
407 return 1;
408
409 seq = cpu_to_be32(sequence);
410 csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
411 csum32 = jbd2_chksum(j, csum32, buf, j->j_blocksize);
412
413 if (jbd2_has_feature_csum3(j))
414 return tag3->t_checksum == cpu_to_be32(csum32);
415 else
416 return tag->t_checksum == cpu_to_be16(csum32);
417 }
418
419 static int do_one_pass(journal_t *journal,
420 struct recovery_info *info, enum passtype pass)
421 {
422 unsigned int first_commit_ID, next_commit_ID;
423 unsigned long next_log_block;
424 int err, success = 0;
425 journal_superblock_t * sb;
426 journal_header_t * tmp;
427 struct buffer_head * bh;
428 unsigned int sequence;
429 int blocktype;
430 int tag_bytes = journal_tag_bytes(journal);
431 __u32 crc32_sum = ~0; /* Transactional Checksums */
432 int descr_csum_size = 0;
433 int block_error = 0;
434
435 /*
436 * First thing is to establish what we expect to find in the log
437 * (in terms of transaction IDs), and where (in terms of log
438 * block offsets): query the superblock.
439 */
440
441 sb = journal->j_superblock;
442 next_commit_ID = be32_to_cpu(sb->s_sequence);
443 next_log_block = be32_to_cpu(sb->s_start);
444
445 first_commit_ID = next_commit_ID;
446 if (pass == PASS_SCAN)
447 info->start_transaction = first_commit_ID;
448
449 jbd_debug(1, "Starting recovery pass %d\n", pass);
450
451 /*
452 * Now we walk through the log, transaction by transaction,
453 * making sure that each transaction has a commit block in the
454 * expected place. Each complete transaction gets replayed back
455 * into the main filesystem.
456 */
457
458 while (1) {
459 int flags;
460 char * tagp;
461 journal_block_tag_t * tag;
462 struct buffer_head * obh;
463 struct buffer_head * nbh;
464
465 cond_resched();
466
467 /* If we already know where to stop the log traversal,
468 * check right now that we haven't gone past the end of
469 * the log. */
470
471 if (pass != PASS_SCAN)
472 if (tid_geq(next_commit_ID, info->end_transaction))
473 break;
474
475 jbd_debug(2, "Scanning for sequence ID %u at %lu/%lu\n",
476 next_commit_ID, next_log_block, journal->j_last);
477
478 /* Skip over each chunk of the transaction looking
479 * either the next descriptor block or the final commit
480 * record. */
481
482 jbd_debug(3, "JBD2: checking block %ld\n", next_log_block);
483 err = jread(&bh, journal, next_log_block);
484 if (err)
485 goto failed;
486
487 next_log_block++;
488 wrap(journal, next_log_block);
489
490 /* What kind of buffer is it?
491 *
492 * If it is a descriptor block, check that it has the
493 * expected sequence number. Otherwise, we're all done
494 * here. */
495
496 tmp = (journal_header_t *)bh->b_data;
497
498 if (tmp->h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER)) {
499 brelse(bh);
500 break;
501 }
502
503 blocktype = be32_to_cpu(tmp->h_blocktype);
504 sequence = be32_to_cpu(tmp->h_sequence);
505 jbd_debug(3, "Found magic %d, sequence %d\n",
506 blocktype, sequence);
507
508 if (sequence != next_commit_ID) {
509 brelse(bh);
510 break;
511 }
512
513 /* OK, we have a valid descriptor block which matches
514 * all of the sequence number checks. What are we going
515 * to do with it? That depends on the pass... */
516
517 switch(blocktype) {
518 case JBD2_DESCRIPTOR_BLOCK:
519 /* Verify checksum first */
520 if (jbd2_journal_has_csum_v2or3(journal))
521 descr_csum_size =
522 sizeof(struct jbd2_journal_block_tail);
523 if (descr_csum_size > 0 &&
524 !jbd2_descriptor_block_csum_verify(journal,
525 bh->b_data)) {
526 printk(KERN_ERR "JBD2: Invalid checksum "
527 "recovering block %lu in log\n",
528 next_log_block);
529 err = -EFSBADCRC;
530 brelse(bh);
531 goto failed;
532 }
533
534 /* If it is a valid descriptor block, replay it
535 * in pass REPLAY; if journal_checksums enabled, then
536 * calculate checksums in PASS_SCAN, otherwise,
537 * just skip over the blocks it describes. */
538 if (pass != PASS_REPLAY) {
539 if (pass == PASS_SCAN &&
540 jbd2_has_feature_checksum(journal) &&
541 !info->end_transaction) {
542 if (calc_chksums(journal, bh,
543 &next_log_block,
544 &crc32_sum)) {
545 put_bh(bh);
546 break;
547 }
548 put_bh(bh);
549 continue;
550 }
551 next_log_block += count_tags(journal, bh);
552 wrap(journal, next_log_block);
553 put_bh(bh);
554 continue;
555 }
556
557 /* A descriptor block: we can now write all of
558 * the data blocks. Yay, useful work is finally
559 * getting done here! */
560
561 tagp = &bh->b_data[sizeof(journal_header_t)];
562 while ((tagp - bh->b_data + tag_bytes)
563 <= journal->j_blocksize - descr_csum_size) {
564 unsigned long io_block;
565
566 tag = (journal_block_tag_t *) tagp;
567 flags = be16_to_cpu(tag->t_flags);
568
569 io_block = next_log_block++;
570 wrap(journal, next_log_block);
571 err = jread(&obh, journal, io_block);
572 if (err) {
573 /* Recover what we can, but
574 * report failure at the end. */
575 success = err;
576 printk(KERN_ERR
577 "JBD2: IO error %d recovering "
578 "block %ld in log\n",
579 err, io_block);
580 } else {
581 unsigned long long blocknr;
582
583 J_ASSERT(obh != NULL);
584 blocknr = read_tag_block(journal,
585 tag);
586
587 /* If the block has been
588 * revoked, then we're all done
589 * here. */
590 if (jbd2_journal_test_revoke
591 (journal, blocknr,
592 next_commit_ID)) {
593 brelse(obh);
594 ++info->nr_revoke_hits;
595 goto skip_write;
596 }
597
598 /* Look for block corruption */
599 if (!jbd2_block_tag_csum_verify(
600 journal, tag, obh->b_data,
601 be32_to_cpu(tmp->h_sequence))) {
602 brelse(obh);
603 success = -EFSBADCRC;
604 printk(KERN_ERR "JBD2: Invalid "
605 "checksum recovering "
606 "block %llu in log\n",
607 blocknr);
608 block_error = 1;
609 goto skip_write;
610 }
611
612 /* Find a buffer for the new
613 * data being restored */
614 nbh = __getblk(journal->j_fs_dev,
615 blocknr,
616 journal->j_blocksize);
617 if (nbh == NULL) {
618 printk(KERN_ERR
619 "JBD2: Out of memory "
620 "during recovery.\n");
621 err = -ENOMEM;
622 brelse(bh);
623 brelse(obh);
624 goto failed;
625 }
626
627 lock_buffer(nbh);
628 memcpy(nbh->b_data, obh->b_data,
629 journal->j_blocksize);
630 if (flags & JBD2_FLAG_ESCAPE) {
631 *((__be32 *)nbh->b_data) =
632 cpu_to_be32(JBD2_MAGIC_NUMBER);
633 }
634
635 BUFFER_TRACE(nbh, "marking dirty");
636 set_buffer_uptodate(nbh);
637 mark_buffer_dirty(nbh);
638 BUFFER_TRACE(nbh, "marking uptodate");
639 ++info->nr_replays;
640 /* ll_rw_block(WRITE, 1, &nbh); */
641 unlock_buffer(nbh);
642 brelse(obh);
643 brelse(nbh);
644 }
645
646 skip_write:
647 tagp += tag_bytes;
648 if (!(flags & JBD2_FLAG_SAME_UUID))
649 tagp += 16;
650
651 if (flags & JBD2_FLAG_LAST_TAG)
652 break;
653 }
654
655 brelse(bh);
656 continue;
657
658 case JBD2_COMMIT_BLOCK:
659 /* How to differentiate between interrupted commit
660 * and journal corruption ?
661 *
662 * {nth transaction}
663 * Checksum Verification Failed
664 * |
665 * ____________________
666 * | |
667 * async_commit sync_commit
668 * | |
669 * | GO TO NEXT "Journal Corruption"
670 * | TRANSACTION
671 * |
672 * {(n+1)th transanction}
673 * |
674 * _______|______________
675 * | |
676 * Commit block found Commit block not found
677 * | |
678 * "Journal Corruption" |
679 * _____________|_________
680 * | |
681 * nth trans corrupt OR nth trans
682 * and (n+1)th interrupted interrupted
683 * before commit block
684 * could reach the disk.
685 * (Cannot find the difference in above
686 * mentioned conditions. Hence assume
687 * "Interrupted Commit".)
688 */
689
690 /* Found an expected commit block: if checksums
691 * are present verify them in PASS_SCAN; else not
692 * much to do other than move on to the next sequence
693 * number. */
694 if (pass == PASS_SCAN &&
695 jbd2_has_feature_checksum(journal)) {
696 int chksum_err, chksum_seen;
697 struct commit_header *cbh =
698 (struct commit_header *)bh->b_data;
699 unsigned found_chksum =
700 be32_to_cpu(cbh->h_chksum[0]);
701
702 chksum_err = chksum_seen = 0;
703
704 if (info->end_transaction) {
705 journal->j_failed_commit =
706 info->end_transaction;
707 brelse(bh);
708 break;
709 }
710
711 if (crc32_sum == found_chksum &&
712 cbh->h_chksum_type == JBD2_CRC32_CHKSUM &&
713 cbh->h_chksum_size ==
714 JBD2_CRC32_CHKSUM_SIZE)
715 chksum_seen = 1;
716 else if (!(cbh->h_chksum_type == 0 &&
717 cbh->h_chksum_size == 0 &&
718 found_chksum == 0 &&
719 !chksum_seen))
720 /*
721 * If fs is mounted using an old kernel and then
722 * kernel with journal_chksum is used then we
723 * get a situation where the journal flag has
724 * checksum flag set but checksums are not
725 * present i.e chksum = 0, in the individual
726 * commit blocks.
727 * Hence to avoid checksum failures, in this
728 * situation, this extra check is added.
729 */
730 chksum_err = 1;
731
732 if (chksum_err) {
733 info->end_transaction = next_commit_ID;
734
735 if (!jbd2_has_feature_async_commit(journal)) {
736 journal->j_failed_commit =
737 next_commit_ID;
738 brelse(bh);
739 break;
740 }
741 }
742 crc32_sum = ~0;
743 }
744 if (pass == PASS_SCAN &&
745 !jbd2_commit_block_csum_verify(journal,
746 bh->b_data)) {
747 info->end_transaction = next_commit_ID;
748
749 if (!jbd2_has_feature_async_commit(journal)) {
750 journal->j_failed_commit =
751 next_commit_ID;
752 brelse(bh);
753 break;
754 }
755 }
756 brelse(bh);
757 next_commit_ID++;
758 continue;
759
760 case JBD2_REVOKE_BLOCK:
761 /* If we aren't in the REVOKE pass, then we can
762 * just skip over this block. */
763 if (pass != PASS_REVOKE) {
764 brelse(bh);
765 continue;
766 }
767
768 err = scan_revoke_records(journal, bh,
769 next_commit_ID, info);
770 brelse(bh);
771 if (err)
772 goto failed;
773 continue;
774
775 default:
776 jbd_debug(3, "Unrecognised magic %d, end of scan.\n",
777 blocktype);
778 brelse(bh);
779 goto done;
780 }
781 }
782
783 done:
784 /*
785 * We broke out of the log scan loop: either we came to the
786 * known end of the log or we found an unexpected block in the
787 * log. If the latter happened, then we know that the "current"
788 * transaction marks the end of the valid log.
789 */
790
791 if (pass == PASS_SCAN) {
792 if (!info->end_transaction)
793 info->end_transaction = next_commit_ID;
794 } else {
795 /* It's really bad news if different passes end up at
796 * different places (but possible due to IO errors). */
797 if (info->end_transaction != next_commit_ID) {
798 printk(KERN_ERR "JBD2: recovery pass %d ended at "
799 "transaction %u, expected %u\n",
800 pass, next_commit_ID, info->end_transaction);
801 if (!success)
802 success = -EIO;
803 }
804 }
805 if (block_error && success == 0)
806 success = -EIO;
807 return success;
808
809 failed:
810 return err;
811 }
812
813 /* Scan a revoke record, marking all blocks mentioned as revoked. */
814
815 static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
816 tid_t sequence, struct recovery_info *info)
817 {
818 jbd2_journal_revoke_header_t *header;
819 int offset, max;
820 int csum_size = 0;
821 __u32 rcount;
822 int record_len = 4;
823
824 header = (jbd2_journal_revoke_header_t *) bh->b_data;
825 offset = sizeof(jbd2_journal_revoke_header_t);
826 rcount = be32_to_cpu(header->r_count);
827
828 if (!jbd2_descriptor_block_csum_verify(journal, header))
829 return -EFSBADCRC;
830
831 if (jbd2_journal_has_csum_v2or3(journal))
832 csum_size = sizeof(struct jbd2_journal_block_tail);
833 if (rcount > journal->j_blocksize - csum_size)
834 return -EINVAL;
835 max = rcount;
836
837 if (jbd2_has_feature_64bit(journal))
838 record_len = 8;
839
840 while (offset + record_len <= max) {
841 unsigned long long blocknr;
842 int err;
843
844 if (record_len == 4)
845 blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset)));
846 else
847 blocknr = be64_to_cpu(* ((__be64 *) (bh->b_data+offset)));
848 offset += record_len;
849 err = jbd2_journal_set_revoke(journal, blocknr, sequence);
850 if (err)
851 return err;
852 ++info->nr_revokes;
853 }
854 return 0;
855 }
Linux with added FPC-III support