blob: 7199db52b2fdb5ab5a198a52e1ab7ac2194a2da3 [file] [log] [blame]
Dave Kleikamp470decc2006-10-11 01:20:57 -07001/*
Uwe Kleine-König58862692007-05-09 07:51:49 +02002 * linux/fs/jbd2/recovery.c
Dave Kleikamp470decc2006-10-11 01:20:57 -07003 *
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>
Mingming Caof7f4bcc2006-10-11 01:20:59 -070021#include <linux/jbd2.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070022#include <linux/errno.h>
23#include <linux/slab.h>
Girish Shilamkar818d2762008-01-28 23:58:27 -050024#include <linux/crc32.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070025#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 */
31struct 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
41enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY};
42static int do_one_pass(journal_t *journal,
43 struct recovery_info *info, enum passtype pass);
44static 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 */
50static 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
70static int do_readahead(journal_t *journal, unsigned int start)
71{
72 int err;
73 unsigned int max, nbufs, next;
Mingming Cao18eba7a2006-10-11 01:21:13 -070074 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -070075 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++) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -070090 err = jbd2_journal_bmap(journal, next, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -070091
92 if (err) {
93 printk (KERN_ERR "JBD: 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
119failed:
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
132static int jread(struct buffer_head **bhp, journal_t *journal,
133 unsigned int offset)
134{
135 int err;
Mingming Cao18eba7a2006-10-11 01:21:13 -0700136 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700137 struct buffer_head *bh;
138
139 *bhp = NULL;
140
141 if (offset >= journal->j_maxlen) {
142 printk(KERN_ERR "JBD: corrupted journal superblock\n");
143 return -EIO;
144 }
145
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700146 err = jbd2_journal_bmap(journal, offset, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700147
148 if (err) {
149 printk (KERN_ERR "JBD: 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 "JBD: 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
178/*
179 * Count the number of in-use tags in a journal descriptor block.
180 */
181
Zach Brownb517bea2006-10-11 01:21:08 -0700182static int count_tags(journal_t *journal, struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700183{
184 char * tagp;
185 journal_block_tag_t * tag;
Zach Brownb517bea2006-10-11 01:21:08 -0700186 int nr = 0, size = journal->j_blocksize;
187 int tag_bytes = journal_tag_bytes(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700188
189 tagp = &bh->b_data[sizeof(journal_header_t)];
190
Zach Brownb517bea2006-10-11 01:21:08 -0700191 while ((tagp - bh->b_data + tag_bytes) <= size) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700192 tag = (journal_block_tag_t *) tagp;
193
194 nr++;
Zach Brownb517bea2006-10-11 01:21:08 -0700195 tagp += tag_bytes;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700196 if (!(tag->t_flags & cpu_to_be32(JBD2_FLAG_SAME_UUID)))
Dave Kleikamp470decc2006-10-11 01:20:57 -0700197 tagp += 16;
198
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700199 if (tag->t_flags & cpu_to_be32(JBD2_FLAG_LAST_TAG))
Dave Kleikamp470decc2006-10-11 01:20:57 -0700200 break;
201 }
202
203 return nr;
204}
205
206
207/* Make sure we wrap around the log correctly! */
208#define wrap(journal, var) \
209do { \
210 if (var >= (journal)->j_last) \
211 var -= ((journal)->j_last - (journal)->j_first); \
212} while (0)
213
214/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700215 * jbd2_journal_recover - recovers a on-disk journal
Dave Kleikamp470decc2006-10-11 01:20:57 -0700216 * @journal: the journal to recover
217 *
218 * The primary function for recovering the log contents when mounting a
219 * journaled device.
220 *
221 * Recovery is done in three passes. In the first pass, we look for the
222 * end of the log. In the second, we assemble the list of revoke
223 * blocks. In the third and final pass, we replay any un-revoked blocks
224 * in the log.
225 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700226int jbd2_journal_recover(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700227{
228 int err;
229 journal_superblock_t * sb;
230
231 struct recovery_info info;
232
233 memset(&info, 0, sizeof(info));
234 sb = journal->j_superblock;
235
236 /*
237 * The journal superblock's s_start field (the current log head)
238 * is always zero if, and only if, the journal was cleanly
239 * unmounted.
240 */
241
242 if (!sb->s_start) {
243 jbd_debug(1, "No recovery required, last transaction %d\n",
244 be32_to_cpu(sb->s_sequence));
245 journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1;
246 return 0;
247 }
248
249 err = do_one_pass(journal, &info, PASS_SCAN);
250 if (!err)
251 err = do_one_pass(journal, &info, PASS_REVOKE);
252 if (!err)
253 err = do_one_pass(journal, &info, PASS_REPLAY);
254
Mingming Caob38bd332007-07-19 01:48:35 -0700255 jbd_debug(1, "JBD: recovery, exit status %d, "
Dave Kleikamp470decc2006-10-11 01:20:57 -0700256 "recovered transactions %u to %u\n",
257 err, info.start_transaction, info.end_transaction);
Mingming Caob38bd332007-07-19 01:48:35 -0700258 jbd_debug(1, "JBD: Replayed %d and revoked %d/%d blocks\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -0700259 info.nr_replays, info.nr_revoke_hits, info.nr_revokes);
260
261 /* Restart the log at the next transaction ID, thus invalidating
262 * any existing commit records in the log. */
263 journal->j_transaction_sequence = ++info.end_transaction;
264
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700265 jbd2_journal_clear_revoke(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700266 sync_blockdev(journal->j_fs_dev);
267 return err;
268}
269
270/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700271 * jbd2_journal_skip_recovery - Start journal and wipe exiting records
Dave Kleikamp470decc2006-10-11 01:20:57 -0700272 * @journal: journal to startup
273 *
274 * Locate any valid recovery information from the journal and set up the
275 * journal structures in memory to ignore it (presumably because the
276 * caller has evidence that it is out of date).
277 * This function does'nt appear to be exorted..
278 *
279 * We perform one pass over the journal to allow us to tell the user how
280 * much recovery information is being erased, and to let us initialise
281 * the journal transaction sequence numbers to the next unused ID.
282 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700283int jbd2_journal_skip_recovery(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700284{
285 int err;
286 journal_superblock_t * sb;
287
288 struct recovery_info info;
289
290 memset (&info, 0, sizeof(info));
291 sb = journal->j_superblock;
292
293 err = do_one_pass(journal, &info, PASS_SCAN);
294
295 if (err) {
296 printk(KERN_ERR "JBD: error %d scanning journal\n", err);
297 ++journal->j_transaction_sequence;
298 } else {
Jose R. Santose23291b2007-07-18 08:57:06 -0400299#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -0700300 int dropped = info.end_transaction - be32_to_cpu(sb->s_sequence);
301#endif
Mingming Caob38bd332007-07-19 01:48:35 -0700302 jbd_debug(1,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700303 "JBD: ignoring %d transaction%s from the journal.\n",
304 dropped, (dropped == 1) ? "" : "s");
305 journal->j_transaction_sequence = ++info.end_transaction;
306 }
307
308 journal->j_tail = 0;
309 return err;
310}
311
Mingming Cao18eba7a2006-10-11 01:21:13 -0700312static inline unsigned long long read_tag_block(int tag_bytes, journal_block_tag_t *tag)
Zach Brownb517bea2006-10-11 01:21:08 -0700313{
Mingming Cao18eba7a2006-10-11 01:21:13 -0700314 unsigned long long block = be32_to_cpu(tag->t_blocknr);
Mingming Caocd02ff02007-10-16 18:38:25 -0400315 if (tag_bytes > JBD2_TAG_SIZE32)
Zach Brownb517bea2006-10-11 01:21:08 -0700316 block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32;
317 return block;
318}
319
Girish Shilamkar818d2762008-01-28 23:58:27 -0500320/*
321 * calc_chksums calculates the checksums for the blocks described in the
322 * descriptor block.
323 */
324static int calc_chksums(journal_t *journal, struct buffer_head *bh,
325 unsigned long *next_log_block, __u32 *crc32_sum)
326{
327 int i, num_blks, err;
328 unsigned long io_block;
329 struct buffer_head *obh;
330
331 num_blks = count_tags(journal, bh);
332 /* Calculate checksum of the descriptor block. */
333 *crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size);
334
335 for (i = 0; i < num_blks; i++) {
336 io_block = (*next_log_block)++;
337 wrap(journal, *next_log_block);
338 err = jread(&obh, journal, io_block);
339 if (err) {
340 printk(KERN_ERR "JBD: IO error %d recovering block "
341 "%lu in log\n", err, io_block);
342 return 1;
343 } else {
344 *crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data,
345 obh->b_size);
346 }
Theodore Ts'o8ea76902008-05-26 10:28:09 -0400347 put_bh(obh);
Girish Shilamkar818d2762008-01-28 23:58:27 -0500348 }
349 return 0;
350}
351
Dave Kleikamp470decc2006-10-11 01:20:57 -0700352static int do_one_pass(journal_t *journal,
353 struct recovery_info *info, enum passtype pass)
354{
355 unsigned int first_commit_ID, next_commit_ID;
356 unsigned long next_log_block;
357 int err, success = 0;
358 journal_superblock_t * sb;
359 journal_header_t * tmp;
360 struct buffer_head * bh;
361 unsigned int sequence;
362 int blocktype;
Zach Brownb517bea2006-10-11 01:21:08 -0700363 int tag_bytes = journal_tag_bytes(journal);
Girish Shilamkar818d2762008-01-28 23:58:27 -0500364 __u32 crc32_sum = ~0; /* Transactional Checksums */
Dave Kleikamp470decc2006-10-11 01:20:57 -0700365
366 /* Precompute the maximum metadata descriptors in a descriptor block */
367 int MAX_BLOCKS_PER_DESC;
368 MAX_BLOCKS_PER_DESC = ((journal->j_blocksize-sizeof(journal_header_t))
Zach Brownb517bea2006-10-11 01:21:08 -0700369 / tag_bytes);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700370
371 /*
372 * First thing is to establish what we expect to find in the log
373 * (in terms of transaction IDs), and where (in terms of log
374 * block offsets): query the superblock.
375 */
376
377 sb = journal->j_superblock;
378 next_commit_ID = be32_to_cpu(sb->s_sequence);
379 next_log_block = be32_to_cpu(sb->s_start);
380
381 first_commit_ID = next_commit_ID;
382 if (pass == PASS_SCAN)
383 info->start_transaction = first_commit_ID;
384
385 jbd_debug(1, "Starting recovery pass %d\n", pass);
386
387 /*
388 * Now we walk through the log, transaction by transaction,
389 * making sure that each transaction has a commit block in the
390 * expected place. Each complete transaction gets replayed back
391 * into the main filesystem.
392 */
393
394 while (1) {
395 int flags;
396 char * tagp;
397 journal_block_tag_t * tag;
398 struct buffer_head * obh;
399 struct buffer_head * nbh;
400
Andi Kleene86e1432008-02-06 01:40:11 -0800401 cond_resched();
Dave Kleikamp470decc2006-10-11 01:20:57 -0700402
403 /* If we already know where to stop the log traversal,
404 * check right now that we haven't gone past the end of
405 * the log. */
406
407 if (pass != PASS_SCAN)
408 if (tid_geq(next_commit_ID, info->end_transaction))
409 break;
410
411 jbd_debug(2, "Scanning for sequence ID %u at %lu/%lu\n",
412 next_commit_ID, next_log_block, journal->j_last);
413
414 /* Skip over each chunk of the transaction looking
415 * either the next descriptor block or the final commit
416 * record. */
417
418 jbd_debug(3, "JBD: checking block %ld\n", next_log_block);
419 err = jread(&bh, journal, next_log_block);
420 if (err)
421 goto failed;
422
423 next_log_block++;
424 wrap(journal, next_log_block);
425
426 /* What kind of buffer is it?
427 *
428 * If it is a descriptor block, check that it has the
429 * expected sequence number. Otherwise, we're all done
430 * here. */
431
432 tmp = (journal_header_t *)bh->b_data;
433
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700434 if (tmp->h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER)) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700435 brelse(bh);
436 break;
437 }
438
439 blocktype = be32_to_cpu(tmp->h_blocktype);
440 sequence = be32_to_cpu(tmp->h_sequence);
441 jbd_debug(3, "Found magic %d, sequence %d\n",
442 blocktype, sequence);
443
444 if (sequence != next_commit_ID) {
445 brelse(bh);
446 break;
447 }
448
449 /* OK, we have a valid descriptor block which matches
450 * all of the sequence number checks. What are we going
451 * to do with it? That depends on the pass... */
452
453 switch(blocktype) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700454 case JBD2_DESCRIPTOR_BLOCK:
Dave Kleikamp470decc2006-10-11 01:20:57 -0700455 /* If it is a valid descriptor block, replay it
Girish Shilamkar818d2762008-01-28 23:58:27 -0500456 * in pass REPLAY; if journal_checksums enabled, then
457 * calculate checksums in PASS_SCAN, otherwise,
458 * just skip over the blocks it describes. */
Dave Kleikamp470decc2006-10-11 01:20:57 -0700459 if (pass != PASS_REPLAY) {
Girish Shilamkar818d2762008-01-28 23:58:27 -0500460 if (pass == PASS_SCAN &&
461 JBD2_HAS_COMPAT_FEATURE(journal,
462 JBD2_FEATURE_COMPAT_CHECKSUM) &&
463 !info->end_transaction) {
464 if (calc_chksums(journal, bh,
465 &next_log_block,
466 &crc32_sum)) {
467 put_bh(bh);
468 break;
469 }
470 put_bh(bh);
471 continue;
472 }
Zach Brownb517bea2006-10-11 01:21:08 -0700473 next_log_block += count_tags(journal, bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700474 wrap(journal, next_log_block);
Girish Shilamkar818d2762008-01-28 23:58:27 -0500475 put_bh(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700476 continue;
477 }
478
479 /* A descriptor block: we can now write all of
480 * the data blocks. Yay, useful work is finally
481 * getting done here! */
482
483 tagp = &bh->b_data[sizeof(journal_header_t)];
Zach Brownb517bea2006-10-11 01:21:08 -0700484 while ((tagp - bh->b_data + tag_bytes)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700485 <= journal->j_blocksize) {
486 unsigned long io_block;
487
488 tag = (journal_block_tag_t *) tagp;
489 flags = be32_to_cpu(tag->t_flags);
490
491 io_block = next_log_block++;
492 wrap(journal, next_log_block);
493 err = jread(&obh, journal, io_block);
494 if (err) {
495 /* Recover what we can, but
496 * report failure at the end. */
497 success = err;
498 printk (KERN_ERR
499 "JBD: IO error %d recovering "
500 "block %ld in log\n",
501 err, io_block);
502 } else {
Mingming Cao18eba7a2006-10-11 01:21:13 -0700503 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700504
505 J_ASSERT(obh != NULL);
Zach Brownb517bea2006-10-11 01:21:08 -0700506 blocknr = read_tag_block(tag_bytes,
507 tag);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700508
509 /* If the block has been
510 * revoked, then we're all done
511 * here. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700512 if (jbd2_journal_test_revoke
Dave Kleikamp470decc2006-10-11 01:20:57 -0700513 (journal, blocknr,
514 next_commit_ID)) {
515 brelse(obh);
516 ++info->nr_revoke_hits;
517 goto skip_write;
518 }
519
520 /* Find a buffer for the new
521 * data being restored */
522 nbh = __getblk(journal->j_fs_dev,
523 blocknr,
524 journal->j_blocksize);
525 if (nbh == NULL) {
526 printk(KERN_ERR
527 "JBD: Out of memory "
528 "during recovery.\n");
529 err = -ENOMEM;
530 brelse(bh);
531 brelse(obh);
532 goto failed;
533 }
534
535 lock_buffer(nbh);
536 memcpy(nbh->b_data, obh->b_data,
537 journal->j_blocksize);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700538 if (flags & JBD2_FLAG_ESCAPE) {
Duane Griffind0025672008-03-19 17:00:54 -0700539 *((__be32 *)nbh->b_data) =
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700540 cpu_to_be32(JBD2_MAGIC_NUMBER);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700541 }
542
543 BUFFER_TRACE(nbh, "marking dirty");
544 set_buffer_uptodate(nbh);
545 mark_buffer_dirty(nbh);
546 BUFFER_TRACE(nbh, "marking uptodate");
547 ++info->nr_replays;
548 /* ll_rw_block(WRITE, 1, &nbh); */
549 unlock_buffer(nbh);
550 brelse(obh);
551 brelse(nbh);
552 }
553
554 skip_write:
Zach Brownb517bea2006-10-11 01:21:08 -0700555 tagp += tag_bytes;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700556 if (!(flags & JBD2_FLAG_SAME_UUID))
Dave Kleikamp470decc2006-10-11 01:20:57 -0700557 tagp += 16;
558
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700559 if (flags & JBD2_FLAG_LAST_TAG)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700560 break;
561 }
562
563 brelse(bh);
564 continue;
565
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700566 case JBD2_COMMIT_BLOCK:
Girish Shilamkar818d2762008-01-28 23:58:27 -0500567 /* How to differentiate between interrupted commit
568 * and journal corruption ?
569 *
570 * {nth transaction}
571 * Checksum Verification Failed
572 * |
573 * ____________________
574 * | |
575 * async_commit sync_commit
576 * | |
577 * | GO TO NEXT "Journal Corruption"
578 * | TRANSACTION
579 * |
580 * {(n+1)th transanction}
581 * |
582 * _______|______________
583 * | |
584 * Commit block found Commit block not found
585 * | |
586 * "Journal Corruption" |
587 * _____________|_________
588 * | |
589 * nth trans corrupt OR nth trans
590 * and (n+1)th interrupted interrupted
591 * before commit block
592 * could reach the disk.
593 * (Cannot find the difference in above
594 * mentioned conditions. Hence assume
595 * "Interrupted Commit".)
596 */
597
598 /* Found an expected commit block: if checksums
599 * are present verify them in PASS_SCAN; else not
600 * much to do other than move on to the next sequence
Dave Kleikamp470decc2006-10-11 01:20:57 -0700601 * number. */
Girish Shilamkar818d2762008-01-28 23:58:27 -0500602 if (pass == PASS_SCAN &&
603 JBD2_HAS_COMPAT_FEATURE(journal,
604 JBD2_FEATURE_COMPAT_CHECKSUM)) {
605 int chksum_err, chksum_seen;
606 struct commit_header *cbh =
607 (struct commit_header *)bh->b_data;
608 unsigned found_chksum =
609 be32_to_cpu(cbh->h_chksum[0]);
610
611 chksum_err = chksum_seen = 0;
612
613 if (info->end_transaction) {
614 printk(KERN_ERR "JBD: Transaction %u "
615 "found to be corrupt.\n",
616 next_commit_ID - 1);
617 brelse(bh);
618 break;
619 }
620
621 if (crc32_sum == found_chksum &&
622 cbh->h_chksum_type == JBD2_CRC32_CHKSUM &&
623 cbh->h_chksum_size ==
624 JBD2_CRC32_CHKSUM_SIZE)
625 chksum_seen = 1;
626 else if (!(cbh->h_chksum_type == 0 &&
627 cbh->h_chksum_size == 0 &&
628 found_chksum == 0 &&
629 !chksum_seen))
630 /*
631 * If fs is mounted using an old kernel and then
632 * kernel with journal_chksum is used then we
633 * get a situation where the journal flag has
634 * checksum flag set but checksums are not
635 * present i.e chksum = 0, in the individual
636 * commit blocks.
637 * Hence to avoid checksum failures, in this
638 * situation, this extra check is added.
639 */
640 chksum_err = 1;
641
642 if (chksum_err) {
643 info->end_transaction = next_commit_ID;
644
Aneesh Kumar K.V4d605172008-02-05 10:56:15 -0500645 if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
Girish Shilamkar818d2762008-01-28 23:58:27 -0500646 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)){
647 printk(KERN_ERR
648 "JBD: Transaction %u "
649 "found to be corrupt.\n",
650 next_commit_ID);
651 brelse(bh);
652 break;
653 }
654 }
655 crc32_sum = ~0;
656 }
Dave Kleikamp470decc2006-10-11 01:20:57 -0700657 brelse(bh);
658 next_commit_ID++;
659 continue;
660
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700661 case JBD2_REVOKE_BLOCK:
Dave Kleikamp470decc2006-10-11 01:20:57 -0700662 /* If we aren't in the REVOKE pass, then we can
663 * just skip over this block. */
664 if (pass != PASS_REVOKE) {
665 brelse(bh);
666 continue;
667 }
668
669 err = scan_revoke_records(journal, bh,
670 next_commit_ID, info);
671 brelse(bh);
672 if (err)
673 goto failed;
674 continue;
675
676 default:
677 jbd_debug(3, "Unrecognised magic %d, end of scan.\n",
678 blocktype);
679 brelse(bh);
680 goto done;
681 }
682 }
683
684 done:
685 /*
686 * We broke out of the log scan loop: either we came to the
687 * known end of the log or we found an unexpected block in the
688 * log. If the latter happened, then we know that the "current"
689 * transaction marks the end of the valid log.
690 */
691
Girish Shilamkar818d2762008-01-28 23:58:27 -0500692 if (pass == PASS_SCAN) {
693 if (!info->end_transaction)
694 info->end_transaction = next_commit_ID;
695 } else {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700696 /* It's really bad news if different passes end up at
697 * different places (but possible due to IO errors). */
698 if (info->end_transaction != next_commit_ID) {
699 printk (KERN_ERR "JBD: recovery pass %d ended at "
700 "transaction %u, expected %u\n",
701 pass, next_commit_ID, info->end_transaction);
702 if (!success)
703 success = -EIO;
704 }
705 }
706
707 return success;
708
709 failed:
710 return err;
711}
712
713
714/* Scan a revoke record, marking all blocks mentioned as revoked. */
715
716static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
717 tid_t sequence, struct recovery_info *info)
718{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700719 jbd2_journal_revoke_header_t *header;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700720 int offset, max;
Zach Brownb517bea2006-10-11 01:21:08 -0700721 int record_len = 4;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700722
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700723 header = (jbd2_journal_revoke_header_t *) bh->b_data;
724 offset = sizeof(jbd2_journal_revoke_header_t);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700725 max = be32_to_cpu(header->r_count);
726
Zach Brownb517bea2006-10-11 01:21:08 -0700727 if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
728 record_len = 8;
729
730 while (offset + record_len <= max) {
Mingming Cao18eba7a2006-10-11 01:21:13 -0700731 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700732 int err;
733
Zach Brownb517bea2006-10-11 01:21:08 -0700734 if (record_len == 4)
735 blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset)));
736 else
737 blocknr = be64_to_cpu(* ((__be64 *) (bh->b_data+offset)));
738 offset += record_len;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700739 err = jbd2_journal_set_revoke(journal, blocknr, sequence);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700740 if (err)
741 return err;
742 ++info->nr_revokes;
743 }
744 return 0;
745}