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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>
Girish Shilamkar818d2762008-01-28 23:58:27 -050023#include <linux/crc32.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070024#endif
25
26/*
27 * Maintain information about the progress of the recovery job, so that
28 * the different passes can carry information between them.
29 */
30struct recovery_info
31{
32 tid_t start_transaction;
33 tid_t end_transaction;
34
35 int nr_replays;
36 int nr_revokes;
37 int nr_revoke_hits;
38};
39
40enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY};
41static int do_one_pass(journal_t *journal,
42 struct recovery_info *info, enum passtype pass);
43static int scan_revoke_records(journal_t *, struct buffer_head *,
44 tid_t, struct recovery_info *);
45
46#ifdef __KERNEL__
47
48/* Release readahead buffers after use */
49static void journal_brelse_array(struct buffer_head *b[], int n)
50{
51 while (--n >= 0)
52 brelse (b[n]);
53}
54
55
56/*
57 * When reading from the journal, we are going through the block device
58 * layer directly and so there is no readahead being done for us. We
59 * need to implement any readahead ourselves if we want it to happen at
60 * all. Recovery is basically one long sequential read, so make sure we
61 * do the IO in reasonably large chunks.
62 *
63 * This is not so critical that we need to be enormously clever about
64 * the readahead size, though. 128K is a purely arbitrary, good-enough
65 * fixed value.
66 */
67
68#define MAXBUF 8
69static int do_readahead(journal_t *journal, unsigned int start)
70{
71 int err;
72 unsigned int max, nbufs, next;
Mingming Cao18eba7a2006-10-11 01:21:13 -070073 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -070074 struct buffer_head *bh;
75
76 struct buffer_head * bufs[MAXBUF];
77
78 /* Do up to 128K of readahead */
79 max = start + (128 * 1024 / journal->j_blocksize);
80 if (max > journal->j_maxlen)
81 max = journal->j_maxlen;
82
83 /* Do the readahead itself. We'll submit MAXBUF buffer_heads at
84 * a time to the block device IO layer. */
85
86 nbufs = 0;
87
88 for (next = start; next < max; next++) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -070089 err = jbd2_journal_bmap(journal, next, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -070090
91 if (err) {
Eryu Guanf2a44522011-11-01 19:09:18 -040092 printk(KERN_ERR "JBD2: bad block at offset %u\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -070093 next);
94 goto failed;
95 }
96
97 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
98 if (!bh) {
99 err = -ENOMEM;
100 goto failed;
101 }
102
103 if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
104 bufs[nbufs++] = bh;
105 if (nbufs == MAXBUF) {
106 ll_rw_block(READ, nbufs, bufs);
107 journal_brelse_array(bufs, nbufs);
108 nbufs = 0;
109 }
110 } else
111 brelse(bh);
112 }
113
114 if (nbufs)
115 ll_rw_block(READ, nbufs, bufs);
116 err = 0;
117
118failed:
119 if (nbufs)
120 journal_brelse_array(bufs, nbufs);
121 return err;
122}
123
124#endif /* __KERNEL__ */
125
126
127/*
128 * Read a block from the journal
129 */
130
131static int jread(struct buffer_head **bhp, journal_t *journal,
132 unsigned int offset)
133{
134 int err;
Mingming Cao18eba7a2006-10-11 01:21:13 -0700135 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700136 struct buffer_head *bh;
137
138 *bhp = NULL;
139
140 if (offset >= journal->j_maxlen) {
Eryu Guanf2a44522011-11-01 19:09:18 -0400141 printk(KERN_ERR "JBD2: corrupted journal superblock\n");
Dave Kleikamp470decc2006-10-11 01:20:57 -0700142 return -EIO;
143 }
144
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700145 err = jbd2_journal_bmap(journal, offset, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700146
147 if (err) {
Eryu Guanf2a44522011-11-01 19:09:18 -0400148 printk(KERN_ERR "JBD2: bad block at offset %u\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -0700149 offset);
150 return err;
151 }
152
153 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
154 if (!bh)
155 return -ENOMEM;
156
157 if (!buffer_uptodate(bh)) {
158 /* If this is a brand new buffer, start readahead.
159 Otherwise, we assume we are already reading it. */
160 if (!buffer_req(bh))
161 do_readahead(journal, offset);
162 wait_on_buffer(bh);
163 }
164
165 if (!buffer_uptodate(bh)) {
Eryu Guanf2a44522011-11-01 19:09:18 -0400166 printk(KERN_ERR "JBD2: Failed to read block at offset %u\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -0700167 offset);
168 brelse(bh);
169 return -EIO;
170 }
171
172 *bhp = bh;
173 return 0;
174}
175
176
177/*
178 * Count the number of in-use tags in a journal descriptor block.
179 */
180
Zach Brownb517bea2006-10-11 01:21:08 -0700181static int count_tags(journal_t *journal, struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700182{
183 char * tagp;
184 journal_block_tag_t * tag;
Zach Brownb517bea2006-10-11 01:21:08 -0700185 int nr = 0, size = journal->j_blocksize;
186 int tag_bytes = journal_tag_bytes(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700187
188 tagp = &bh->b_data[sizeof(journal_header_t)];
189
Zach Brownb517bea2006-10-11 01:21:08 -0700190 while ((tagp - bh->b_data + tag_bytes) <= size) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700191 tag = (journal_block_tag_t *) tagp;
192
193 nr++;
Zach Brownb517bea2006-10-11 01:21:08 -0700194 tagp += tag_bytes;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700195 if (!(tag->t_flags & cpu_to_be32(JBD2_FLAG_SAME_UUID)))
Dave Kleikamp470decc2006-10-11 01:20:57 -0700196 tagp += 16;
197
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700198 if (tag->t_flags & cpu_to_be32(JBD2_FLAG_LAST_TAG))
Dave Kleikamp470decc2006-10-11 01:20:57 -0700199 break;
200 }
201
202 return nr;
203}
204
205
206/* Make sure we wrap around the log correctly! */
207#define wrap(journal, var) \
208do { \
209 if (var >= (journal)->j_last) \
210 var -= ((journal)->j_last - (journal)->j_first); \
211} while (0)
212
213/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700214 * jbd2_journal_recover - recovers a on-disk journal
Dave Kleikamp470decc2006-10-11 01:20:57 -0700215 * @journal: the journal to recover
216 *
217 * The primary function for recovering the log contents when mounting a
218 * journaled device.
219 *
220 * Recovery is done in three passes. In the first pass, we look for the
221 * end of the log. In the second, we assemble the list of revoke
222 * blocks. In the third and final pass, we replay any un-revoked blocks
223 * in the log.
224 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700225int jbd2_journal_recover(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700226{
Hidehiro Kawai44519fa2008-10-10 20:29:13 -0400227 int err, err2;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700228 journal_superblock_t * sb;
229
230 struct recovery_info info;
231
232 memset(&info, 0, sizeof(info));
233 sb = journal->j_superblock;
234
235 /*
236 * The journal superblock's s_start field (the current log head)
237 * is always zero if, and only if, the journal was cleanly
238 * unmounted.
239 */
240
241 if (!sb->s_start) {
242 jbd_debug(1, "No recovery required, last transaction %d\n",
243 be32_to_cpu(sb->s_sequence));
244 journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1;
245 return 0;
246 }
247
248 err = do_one_pass(journal, &info, PASS_SCAN);
249 if (!err)
250 err = do_one_pass(journal, &info, PASS_REVOKE);
251 if (!err)
252 err = do_one_pass(journal, &info, PASS_REPLAY);
253
Eryu Guanf2a44522011-11-01 19:09:18 -0400254 jbd_debug(1, "JBD2: recovery, exit status %d, "
Dave Kleikamp470decc2006-10-11 01:20:57 -0700255 "recovered transactions %u to %u\n",
256 err, info.start_transaction, info.end_transaction);
Eryu Guanf2a44522011-11-01 19:09:18 -0400257 jbd_debug(1, "JBD2: Replayed %d and revoked %d/%d blocks\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -0700258 info.nr_replays, info.nr_revoke_hits, info.nr_revokes);
259
260 /* Restart the log at the next transaction ID, thus invalidating
261 * any existing commit records in the log. */
262 journal->j_transaction_sequence = ++info.end_transaction;
263
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700264 jbd2_journal_clear_revoke(journal);
Hidehiro Kawai44519fa2008-10-10 20:29:13 -0400265 err2 = sync_blockdev(journal->j_fs_dev);
266 if (!err)
267 err = err2;
268
Dave Kleikamp470decc2006-10-11 01:20:57 -0700269 return err;
270}
271
272/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700273 * jbd2_journal_skip_recovery - Start journal and wipe exiting records
Dave Kleikamp470decc2006-10-11 01:20:57 -0700274 * @journal: journal to startup
275 *
276 * Locate any valid recovery information from the journal and set up the
277 * journal structures in memory to ignore it (presumably because the
278 * caller has evidence that it is out of date).
279 * This function does'nt appear to be exorted..
280 *
281 * We perform one pass over the journal to allow us to tell the user how
282 * much recovery information is being erased, and to let us initialise
283 * the journal transaction sequence numbers to the next unused ID.
284 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700285int jbd2_journal_skip_recovery(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700286{
287 int err;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700288
289 struct recovery_info info;
290
291 memset (&info, 0, sizeof(info));
Dave Kleikamp470decc2006-10-11 01:20:57 -0700292
293 err = do_one_pass(journal, &info, PASS_SCAN);
294
295 if (err) {
Eryu Guanf2a44522011-11-01 19:09:18 -0400296 printk(KERN_ERR "JBD2: error %d scanning journal\n", err);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700297 ++journal->j_transaction_sequence;
298 } else {
Jose R. Santose23291b2007-07-18 08:57:06 -0400299#ifdef CONFIG_JBD2_DEBUG
Andi Kleen5a0790c2010-06-14 13:28:03 -0400300 int dropped = info.end_transaction -
301 be32_to_cpu(journal->j_superblock->s_sequence);
Mingming Caob38bd332007-07-19 01:48:35 -0700302 jbd_debug(1,
Eryu Guanf2a44522011-11-01 19:09:18 -0400303 "JBD2: ignoring %d transaction%s from the journal.\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -0700304 dropped, (dropped == 1) ? "" : "s");
Theodore Ts'o9a4f6272010-12-18 13:36:33 -0500305#endif
Dave Kleikamp470decc2006-10-11 01:20:57 -0700306 journal->j_transaction_sequence = ++info.end_transaction;
307 }
308
309 journal->j_tail = 0;
310 return err;
311}
312
Mingming Cao18eba7a2006-10-11 01:21:13 -0700313static inline unsigned long long read_tag_block(int tag_bytes, journal_block_tag_t *tag)
Zach Brownb517bea2006-10-11 01:21:08 -0700314{
Mingming Cao18eba7a2006-10-11 01:21:13 -0700315 unsigned long long block = be32_to_cpu(tag->t_blocknr);
Mingming Caocd02ff02007-10-16 18:38:25 -0400316 if (tag_bytes > JBD2_TAG_SIZE32)
Zach Brownb517bea2006-10-11 01:21:08 -0700317 block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32;
318 return block;
319}
320
Girish Shilamkar818d2762008-01-28 23:58:27 -0500321/*
322 * calc_chksums calculates the checksums for the blocks described in the
323 * descriptor block.
324 */
325static int calc_chksums(journal_t *journal, struct buffer_head *bh,
326 unsigned long *next_log_block, __u32 *crc32_sum)
327{
328 int i, num_blks, err;
329 unsigned long io_block;
330 struct buffer_head *obh;
331
332 num_blks = count_tags(journal, bh);
333 /* Calculate checksum of the descriptor block. */
334 *crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size);
335
336 for (i = 0; i < num_blks; i++) {
337 io_block = (*next_log_block)++;
338 wrap(journal, *next_log_block);
339 err = jread(&obh, journal, io_block);
340 if (err) {
Eryu Guanf2a44522011-11-01 19:09:18 -0400341 printk(KERN_ERR "JBD2: IO error %d recovering block "
Girish Shilamkar818d2762008-01-28 23:58:27 -0500342 "%lu in log\n", err, io_block);
343 return 1;
344 } else {
345 *crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data,
346 obh->b_size);
347 }
Theodore Ts'o8ea76902008-05-26 10:28:09 -0400348 put_bh(obh);
Girish Shilamkar818d2762008-01-28 23:58:27 -0500349 }
350 return 0;
351}
352
Dave Kleikamp470decc2006-10-11 01:20:57 -0700353static int do_one_pass(journal_t *journal,
354 struct recovery_info *info, enum passtype pass)
355{
356 unsigned int first_commit_ID, next_commit_ID;
357 unsigned long next_log_block;
358 int err, success = 0;
359 journal_superblock_t * sb;
360 journal_header_t * tmp;
361 struct buffer_head * bh;
362 unsigned int sequence;
363 int blocktype;
Zach Brownb517bea2006-10-11 01:21:08 -0700364 int tag_bytes = journal_tag_bytes(journal);
Girish Shilamkar818d2762008-01-28 23:58:27 -0500365 __u32 crc32_sum = ~0; /* Transactional Checksums */
Dave Kleikamp470decc2006-10-11 01:20:57 -0700366
Dave Kleikamp470decc2006-10-11 01:20:57 -0700367 /*
368 * First thing is to establish what we expect to find in the log
369 * (in terms of transaction IDs), and where (in terms of log
370 * block offsets): query the superblock.
371 */
372
373 sb = journal->j_superblock;
374 next_commit_ID = be32_to_cpu(sb->s_sequence);
375 next_log_block = be32_to_cpu(sb->s_start);
376
377 first_commit_ID = next_commit_ID;
378 if (pass == PASS_SCAN)
379 info->start_transaction = first_commit_ID;
380
381 jbd_debug(1, "Starting recovery pass %d\n", pass);
382
383 /*
384 * Now we walk through the log, transaction by transaction,
385 * making sure that each transaction has a commit block in the
386 * expected place. Each complete transaction gets replayed back
387 * into the main filesystem.
388 */
389
390 while (1) {
391 int flags;
392 char * tagp;
393 journal_block_tag_t * tag;
394 struct buffer_head * obh;
395 struct buffer_head * nbh;
396
Andi Kleene86e1432008-02-06 01:40:11 -0800397 cond_resched();
Dave Kleikamp470decc2006-10-11 01:20:57 -0700398
399 /* If we already know where to stop the log traversal,
400 * check right now that we haven't gone past the end of
401 * the log. */
402
403 if (pass != PASS_SCAN)
404 if (tid_geq(next_commit_ID, info->end_transaction))
405 break;
406
407 jbd_debug(2, "Scanning for sequence ID %u at %lu/%lu\n",
408 next_commit_ID, next_log_block, journal->j_last);
409
410 /* Skip over each chunk of the transaction looking
411 * either the next descriptor block or the final commit
412 * record. */
413
Eryu Guanf2a44522011-11-01 19:09:18 -0400414 jbd_debug(3, "JBD2: checking block %ld\n", next_log_block);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700415 err = jread(&bh, journal, next_log_block);
416 if (err)
417 goto failed;
418
419 next_log_block++;
420 wrap(journal, next_log_block);
421
422 /* What kind of buffer is it?
423 *
424 * If it is a descriptor block, check that it has the
425 * expected sequence number. Otherwise, we're all done
426 * here. */
427
428 tmp = (journal_header_t *)bh->b_data;
429
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700430 if (tmp->h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER)) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700431 brelse(bh);
432 break;
433 }
434
435 blocktype = be32_to_cpu(tmp->h_blocktype);
436 sequence = be32_to_cpu(tmp->h_sequence);
437 jbd_debug(3, "Found magic %d, sequence %d\n",
438 blocktype, sequence);
439
440 if (sequence != next_commit_ID) {
441 brelse(bh);
442 break;
443 }
444
445 /* OK, we have a valid descriptor block which matches
446 * all of the sequence number checks. What are we going
447 * to do with it? That depends on the pass... */
448
449 switch(blocktype) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700450 case JBD2_DESCRIPTOR_BLOCK:
Dave Kleikamp470decc2006-10-11 01:20:57 -0700451 /* If it is a valid descriptor block, replay it
Girish Shilamkar818d2762008-01-28 23:58:27 -0500452 * in pass REPLAY; if journal_checksums enabled, then
453 * calculate checksums in PASS_SCAN, otherwise,
454 * just skip over the blocks it describes. */
Dave Kleikamp470decc2006-10-11 01:20:57 -0700455 if (pass != PASS_REPLAY) {
Girish Shilamkar818d2762008-01-28 23:58:27 -0500456 if (pass == PASS_SCAN &&
457 JBD2_HAS_COMPAT_FEATURE(journal,
458 JBD2_FEATURE_COMPAT_CHECKSUM) &&
459 !info->end_transaction) {
460 if (calc_chksums(journal, bh,
461 &next_log_block,
462 &crc32_sum)) {
463 put_bh(bh);
464 break;
465 }
466 put_bh(bh);
467 continue;
468 }
Zach Brownb517bea2006-10-11 01:21:08 -0700469 next_log_block += count_tags(journal, bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700470 wrap(journal, next_log_block);
Girish Shilamkar818d2762008-01-28 23:58:27 -0500471 put_bh(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700472 continue;
473 }
474
475 /* A descriptor block: we can now write all of
476 * the data blocks. Yay, useful work is finally
477 * getting done here! */
478
479 tagp = &bh->b_data[sizeof(journal_header_t)];
Zach Brownb517bea2006-10-11 01:21:08 -0700480 while ((tagp - bh->b_data + tag_bytes)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700481 <= journal->j_blocksize) {
482 unsigned long io_block;
483
484 tag = (journal_block_tag_t *) tagp;
485 flags = be32_to_cpu(tag->t_flags);
486
487 io_block = next_log_block++;
488 wrap(journal, next_log_block);
489 err = jread(&obh, journal, io_block);
490 if (err) {
491 /* Recover what we can, but
492 * report failure at the end. */
493 success = err;
Eryu Guanf2a44522011-11-01 19:09:18 -0400494 printk(KERN_ERR
495 "JBD2: IO error %d recovering "
Dave Kleikamp470decc2006-10-11 01:20:57 -0700496 "block %ld in log\n",
497 err, io_block);
498 } else {
Mingming Cao18eba7a2006-10-11 01:21:13 -0700499 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700500
501 J_ASSERT(obh != NULL);
Zach Brownb517bea2006-10-11 01:21:08 -0700502 blocknr = read_tag_block(tag_bytes,
503 tag);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700504
505 /* If the block has been
506 * revoked, then we're all done
507 * here. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700508 if (jbd2_journal_test_revoke
Dave Kleikamp470decc2006-10-11 01:20:57 -0700509 (journal, blocknr,
510 next_commit_ID)) {
511 brelse(obh);
512 ++info->nr_revoke_hits;
513 goto skip_write;
514 }
515
516 /* Find a buffer for the new
517 * data being restored */
518 nbh = __getblk(journal->j_fs_dev,
519 blocknr,
520 journal->j_blocksize);
521 if (nbh == NULL) {
522 printk(KERN_ERR
Eryu Guanf2a44522011-11-01 19:09:18 -0400523 "JBD2: Out of memory "
Dave Kleikamp470decc2006-10-11 01:20:57 -0700524 "during recovery.\n");
525 err = -ENOMEM;
526 brelse(bh);
527 brelse(obh);
528 goto failed;
529 }
530
531 lock_buffer(nbh);
532 memcpy(nbh->b_data, obh->b_data,
533 journal->j_blocksize);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700534 if (flags & JBD2_FLAG_ESCAPE) {
Duane Griffind0025672008-03-19 17:00:54 -0700535 *((__be32 *)nbh->b_data) =
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700536 cpu_to_be32(JBD2_MAGIC_NUMBER);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700537 }
538
539 BUFFER_TRACE(nbh, "marking dirty");
540 set_buffer_uptodate(nbh);
541 mark_buffer_dirty(nbh);
542 BUFFER_TRACE(nbh, "marking uptodate");
543 ++info->nr_replays;
544 /* ll_rw_block(WRITE, 1, &nbh); */
545 unlock_buffer(nbh);
546 brelse(obh);
547 brelse(nbh);
548 }
549
550 skip_write:
Zach Brownb517bea2006-10-11 01:21:08 -0700551 tagp += tag_bytes;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700552 if (!(flags & JBD2_FLAG_SAME_UUID))
Dave Kleikamp470decc2006-10-11 01:20:57 -0700553 tagp += 16;
554
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700555 if (flags & JBD2_FLAG_LAST_TAG)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700556 break;
557 }
558
559 brelse(bh);
560 continue;
561
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700562 case JBD2_COMMIT_BLOCK:
Girish Shilamkar818d2762008-01-28 23:58:27 -0500563 /* How to differentiate between interrupted commit
564 * and journal corruption ?
565 *
566 * {nth transaction}
567 * Checksum Verification Failed
568 * |
569 * ____________________
570 * | |
571 * async_commit sync_commit
572 * | |
573 * | GO TO NEXT "Journal Corruption"
574 * | TRANSACTION
575 * |
576 * {(n+1)th transanction}
577 * |
578 * _______|______________
579 * | |
580 * Commit block found Commit block not found
581 * | |
582 * "Journal Corruption" |
583 * _____________|_________
584 * | |
585 * nth trans corrupt OR nth trans
586 * and (n+1)th interrupted interrupted
587 * before commit block
588 * could reach the disk.
589 * (Cannot find the difference in above
590 * mentioned conditions. Hence assume
591 * "Interrupted Commit".)
592 */
593
594 /* Found an expected commit block: if checksums
595 * are present verify them in PASS_SCAN; else not
596 * much to do other than move on to the next sequence
Dave Kleikamp470decc2006-10-11 01:20:57 -0700597 * number. */
Girish Shilamkar818d2762008-01-28 23:58:27 -0500598 if (pass == PASS_SCAN &&
599 JBD2_HAS_COMPAT_FEATURE(journal,
600 JBD2_FEATURE_COMPAT_CHECKSUM)) {
601 int chksum_err, chksum_seen;
602 struct commit_header *cbh =
603 (struct commit_header *)bh->b_data;
604 unsigned found_chksum =
605 be32_to_cpu(cbh->h_chksum[0]);
606
607 chksum_err = chksum_seen = 0;
608
609 if (info->end_transaction) {
Theodore Ts'o624080e2008-06-06 17:50:40 -0400610 journal->j_failed_commit =
611 info->end_transaction;
Girish Shilamkar818d2762008-01-28 23:58:27 -0500612 brelse(bh);
613 break;
614 }
615
616 if (crc32_sum == found_chksum &&
617 cbh->h_chksum_type == JBD2_CRC32_CHKSUM &&
618 cbh->h_chksum_size ==
619 JBD2_CRC32_CHKSUM_SIZE)
620 chksum_seen = 1;
621 else if (!(cbh->h_chksum_type == 0 &&
622 cbh->h_chksum_size == 0 &&
623 found_chksum == 0 &&
624 !chksum_seen))
625 /*
626 * If fs is mounted using an old kernel and then
627 * kernel with journal_chksum is used then we
628 * get a situation where the journal flag has
629 * checksum flag set but checksums are not
630 * present i.e chksum = 0, in the individual
631 * commit blocks.
632 * Hence to avoid checksum failures, in this
633 * situation, this extra check is added.
634 */
635 chksum_err = 1;
636
637 if (chksum_err) {
638 info->end_transaction = next_commit_ID;
639
Aneesh Kumar K.V4d605172008-02-05 10:56:15 -0500640 if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
Girish Shilamkar818d2762008-01-28 23:58:27 -0500641 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)){
Theodore Ts'o624080e2008-06-06 17:50:40 -0400642 journal->j_failed_commit =
643 next_commit_ID;
Girish Shilamkar818d2762008-01-28 23:58:27 -0500644 brelse(bh);
645 break;
646 }
647 }
648 crc32_sum = ~0;
649 }
Dave Kleikamp470decc2006-10-11 01:20:57 -0700650 brelse(bh);
651 next_commit_ID++;
652 continue;
653
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700654 case JBD2_REVOKE_BLOCK:
Dave Kleikamp470decc2006-10-11 01:20:57 -0700655 /* If we aren't in the REVOKE pass, then we can
656 * just skip over this block. */
657 if (pass != PASS_REVOKE) {
658 brelse(bh);
659 continue;
660 }
661
662 err = scan_revoke_records(journal, bh,
663 next_commit_ID, info);
664 brelse(bh);
665 if (err)
666 goto failed;
667 continue;
668
669 default:
670 jbd_debug(3, "Unrecognised magic %d, end of scan.\n",
671 blocktype);
672 brelse(bh);
673 goto done;
674 }
675 }
676
677 done:
678 /*
679 * We broke out of the log scan loop: either we came to the
680 * known end of the log or we found an unexpected block in the
681 * log. If the latter happened, then we know that the "current"
682 * transaction marks the end of the valid log.
683 */
684
Girish Shilamkar818d2762008-01-28 23:58:27 -0500685 if (pass == PASS_SCAN) {
686 if (!info->end_transaction)
687 info->end_transaction = next_commit_ID;
688 } else {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700689 /* It's really bad news if different passes end up at
690 * different places (but possible due to IO errors). */
691 if (info->end_transaction != next_commit_ID) {
Eryu Guanf2a44522011-11-01 19:09:18 -0400692 printk(KERN_ERR "JBD2: recovery pass %d ended at "
Dave Kleikamp470decc2006-10-11 01:20:57 -0700693 "transaction %u, expected %u\n",
694 pass, next_commit_ID, info->end_transaction);
695 if (!success)
696 success = -EIO;
697 }
698 }
699
700 return success;
701
702 failed:
703 return err;
704}
705
706
707/* Scan a revoke record, marking all blocks mentioned as revoked. */
708
709static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
710 tid_t sequence, struct recovery_info *info)
711{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700712 jbd2_journal_revoke_header_t *header;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700713 int offset, max;
Zach Brownb517bea2006-10-11 01:21:08 -0700714 int record_len = 4;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700715
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700716 header = (jbd2_journal_revoke_header_t *) bh->b_data;
717 offset = sizeof(jbd2_journal_revoke_header_t);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700718 max = be32_to_cpu(header->r_count);
719
Zach Brownb517bea2006-10-11 01:21:08 -0700720 if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
721 record_len = 8;
722
723 while (offset + record_len <= max) {
Mingming Cao18eba7a2006-10-11 01:21:13 -0700724 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700725 int err;
726
Zach Brownb517bea2006-10-11 01:21:08 -0700727 if (record_len == 4)
728 blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset)));
729 else
730 blocknr = be64_to_cpu(* ((__be64 *) (bh->b_data+offset)));
731 offset += record_len;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700732 err = jbd2_journal_set_revoke(journal, blocknr, sequence);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700733 if (err)
734 return err;
735 ++info->nr_revokes;
736 }
737 return 0;
738}