Commit | Line | Data |
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470decc6 | 1 | /* |
58862699 | 2 | * linux/fs/jbd2/recovery.c |
470decc6 DK |
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> | |
f7f4bccb | 21 | #include <linux/jbd2.h> |
470decc6 DK |
22 | #include <linux/errno.h> |
23 | #include <linux/slab.h> | |
818d276c | 24 | #include <linux/crc32.h> |
470decc6 DK |
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; | |
18eba7aa | 74 | unsigned long long blocknr; |
470decc6 DK |
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++) { | |
f7f4bccb | 90 | err = jbd2_journal_bmap(journal, next, &blocknr); |
470decc6 DK |
91 | |
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 | ||
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; | |
18eba7aa | 136 | unsigned long long blocknr; |
470decc6 DK |
137 | 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 | ||
f7f4bccb | 146 | err = jbd2_journal_bmap(journal, offset, &blocknr); |
470decc6 DK |
147 | |
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 | ||
b517bea1 | 182 | static int count_tags(journal_t *journal, struct buffer_head *bh) |
470decc6 DK |
183 | { |
184 | char * tagp; | |
185 | journal_block_tag_t * tag; | |
b517bea1 ZB |
186 | int nr = 0, size = journal->j_blocksize; |
187 | int tag_bytes = journal_tag_bytes(journal); | |
470decc6 DK |
188 | |
189 | tagp = &bh->b_data[sizeof(journal_header_t)]; | |
190 | ||
b517bea1 | 191 | while ((tagp - bh->b_data + tag_bytes) <= size) { |
470decc6 DK |
192 | tag = (journal_block_tag_t *) tagp; |
193 | ||
194 | nr++; | |
b517bea1 | 195 | tagp += tag_bytes; |
f7f4bccb | 196 | if (!(tag->t_flags & cpu_to_be32(JBD2_FLAG_SAME_UUID))) |
470decc6 DK |
197 | tagp += 16; |
198 | ||
f7f4bccb | 199 | if (tag->t_flags & cpu_to_be32(JBD2_FLAG_LAST_TAG)) |
470decc6 DK |
200 | break; |
201 | } | |
202 | ||
203 | return nr; | |
204 | } | |
205 | ||
206 | ||
207 | /* Make sure we wrap around the log correctly! */ | |
208 | #define wrap(journal, var) \ | |
209 | do { \ | |
210 | if (var >= (journal)->j_last) \ | |
211 | var -= ((journal)->j_last - (journal)->j_first); \ | |
212 | } while (0) | |
213 | ||
214 | /** | |
f7f4bccb | 215 | * jbd2_journal_recover - recovers a on-disk journal |
470decc6 DK |
216 | * @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 | */ | |
f7f4bccb | 226 | int jbd2_journal_recover(journal_t *journal) |
470decc6 | 227 | { |
44519faf | 228 | int err, err2; |
470decc6 DK |
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 | ||
b38bd33a | 255 | jbd_debug(1, "JBD: recovery, exit status %d, " |
470decc6 DK |
256 | "recovered transactions %u to %u\n", |
257 | err, info.start_transaction, info.end_transaction); | |
b38bd33a | 258 | jbd_debug(1, "JBD: Replayed %d and revoked %d/%d blocks\n", |
470decc6 DK |
259 | 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 | ||
f7f4bccb | 265 | jbd2_journal_clear_revoke(journal); |
44519faf HK |
266 | err2 = sync_blockdev(journal->j_fs_dev); |
267 | if (!err) | |
268 | err = err2; | |
269 | ||
470decc6 DK |
270 | return err; |
271 | } | |
272 | ||
273 | /** | |
f7f4bccb | 274 | * jbd2_journal_skip_recovery - Start journal and wipe exiting records |
470decc6 DK |
275 | * @journal: journal to startup |
276 | * | |
277 | * Locate any valid recovery information from the journal and set up the | |
278 | * journal structures in memory to ignore it (presumably because the | |
279 | * caller has evidence that it is out of date). | |
280 | * This function does'nt appear to be exorted.. | |
281 | * | |
282 | * We perform one pass over the journal to allow us to tell the user how | |
283 | * much recovery information is being erased, and to let us initialise | |
284 | * the journal transaction sequence numbers to the next unused ID. | |
285 | */ | |
f7f4bccb | 286 | int jbd2_journal_skip_recovery(journal_t *journal) |
470decc6 DK |
287 | { |
288 | int err; | |
289 | journal_superblock_t * sb; | |
290 | ||
291 | struct recovery_info info; | |
292 | ||
293 | memset (&info, 0, sizeof(info)); | |
294 | sb = journal->j_superblock; | |
295 | ||
296 | err = do_one_pass(journal, &info, PASS_SCAN); | |
297 | ||
298 | if (err) { | |
299 | printk(KERN_ERR "JBD: error %d scanning journal\n", err); | |
300 | ++journal->j_transaction_sequence; | |
301 | } else { | |
e23291b9 | 302 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
303 | int dropped = info.end_transaction - be32_to_cpu(sb->s_sequence); |
304 | #endif | |
b38bd33a | 305 | jbd_debug(1, |
470decc6 DK |
306 | "JBD: ignoring %d transaction%s from the journal.\n", |
307 | dropped, (dropped == 1) ? "" : "s"); | |
308 | journal->j_transaction_sequence = ++info.end_transaction; | |
309 | } | |
310 | ||
311 | journal->j_tail = 0; | |
312 | return err; | |
313 | } | |
314 | ||
18eba7aa | 315 | static inline unsigned long long read_tag_block(int tag_bytes, journal_block_tag_t *tag) |
b517bea1 | 316 | { |
18eba7aa | 317 | unsigned long long block = be32_to_cpu(tag->t_blocknr); |
cd02ff0b | 318 | if (tag_bytes > JBD2_TAG_SIZE32) |
b517bea1 ZB |
319 | block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32; |
320 | return block; | |
321 | } | |
322 | ||
818d276c GS |
323 | /* |
324 | * calc_chksums calculates the checksums for the blocks described in the | |
325 | * descriptor block. | |
326 | */ | |
327 | static int calc_chksums(journal_t *journal, struct buffer_head *bh, | |
328 | unsigned long *next_log_block, __u32 *crc32_sum) | |
329 | { | |
330 | int i, num_blks, err; | |
331 | unsigned long io_block; | |
332 | struct buffer_head *obh; | |
333 | ||
334 | num_blks = count_tags(journal, bh); | |
335 | /* Calculate checksum of the descriptor block. */ | |
336 | *crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size); | |
337 | ||
338 | for (i = 0; i < num_blks; i++) { | |
339 | io_block = (*next_log_block)++; | |
340 | wrap(journal, *next_log_block); | |
341 | err = jread(&obh, journal, io_block); | |
342 | if (err) { | |
343 | printk(KERN_ERR "JBD: IO error %d recovering block " | |
344 | "%lu in log\n", err, io_block); | |
345 | return 1; | |
346 | } else { | |
347 | *crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data, | |
348 | obh->b_size); | |
349 | } | |
8ea76900 | 350 | put_bh(obh); |
818d276c GS |
351 | } |
352 | return 0; | |
353 | } | |
354 | ||
470decc6 DK |
355 | static int do_one_pass(journal_t *journal, |
356 | struct recovery_info *info, enum passtype pass) | |
357 | { | |
358 | unsigned int first_commit_ID, next_commit_ID; | |
359 | unsigned long next_log_block; | |
360 | int err, success = 0; | |
361 | journal_superblock_t * sb; | |
362 | journal_header_t * tmp; | |
363 | struct buffer_head * bh; | |
364 | unsigned int sequence; | |
365 | int blocktype; | |
b517bea1 | 366 | int tag_bytes = journal_tag_bytes(journal); |
818d276c | 367 | __u32 crc32_sum = ~0; /* Transactional Checksums */ |
470decc6 DK |
368 | |
369 | /* Precompute the maximum metadata descriptors in a descriptor block */ | |
370 | int MAX_BLOCKS_PER_DESC; | |
371 | MAX_BLOCKS_PER_DESC = ((journal->j_blocksize-sizeof(journal_header_t)) | |
b517bea1 | 372 | / tag_bytes); |
470decc6 DK |
373 | |
374 | /* | |
375 | * First thing is to establish what we expect to find in the log | |
376 | * (in terms of transaction IDs), and where (in terms of log | |
377 | * block offsets): query the superblock. | |
378 | */ | |
379 | ||
380 | sb = journal->j_superblock; | |
381 | next_commit_ID = be32_to_cpu(sb->s_sequence); | |
382 | next_log_block = be32_to_cpu(sb->s_start); | |
383 | ||
384 | first_commit_ID = next_commit_ID; | |
385 | if (pass == PASS_SCAN) | |
386 | info->start_transaction = first_commit_ID; | |
387 | ||
388 | jbd_debug(1, "Starting recovery pass %d\n", pass); | |
389 | ||
390 | /* | |
391 | * Now we walk through the log, transaction by transaction, | |
392 | * making sure that each transaction has a commit block in the | |
393 | * expected place. Each complete transaction gets replayed back | |
394 | * into the main filesystem. | |
395 | */ | |
396 | ||
397 | while (1) { | |
398 | int flags; | |
399 | char * tagp; | |
400 | journal_block_tag_t * tag; | |
401 | struct buffer_head * obh; | |
402 | struct buffer_head * nbh; | |
403 | ||
e86e1438 | 404 | cond_resched(); |
470decc6 DK |
405 | |
406 | /* If we already know where to stop the log traversal, | |
407 | * check right now that we haven't gone past the end of | |
408 | * the log. */ | |
409 | ||
410 | if (pass != PASS_SCAN) | |
411 | if (tid_geq(next_commit_ID, info->end_transaction)) | |
412 | break; | |
413 | ||
414 | jbd_debug(2, "Scanning for sequence ID %u at %lu/%lu\n", | |
415 | next_commit_ID, next_log_block, journal->j_last); | |
416 | ||
417 | /* Skip over each chunk of the transaction looking | |
418 | * either the next descriptor block or the final commit | |
419 | * record. */ | |
420 | ||
421 | jbd_debug(3, "JBD: checking block %ld\n", next_log_block); | |
422 | err = jread(&bh, journal, next_log_block); | |
423 | if (err) | |
424 | goto failed; | |
425 | ||
426 | next_log_block++; | |
427 | wrap(journal, next_log_block); | |
428 | ||
429 | /* What kind of buffer is it? | |
430 | * | |
431 | * If it is a descriptor block, check that it has the | |
432 | * expected sequence number. Otherwise, we're all done | |
433 | * here. */ | |
434 | ||
435 | tmp = (journal_header_t *)bh->b_data; | |
436 | ||
f7f4bccb | 437 | if (tmp->h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER)) { |
470decc6 DK |
438 | brelse(bh); |
439 | break; | |
440 | } | |
441 | ||
442 | blocktype = be32_to_cpu(tmp->h_blocktype); | |
443 | sequence = be32_to_cpu(tmp->h_sequence); | |
444 | jbd_debug(3, "Found magic %d, sequence %d\n", | |
445 | blocktype, sequence); | |
446 | ||
447 | if (sequence != next_commit_ID) { | |
448 | brelse(bh); | |
449 | break; | |
450 | } | |
451 | ||
452 | /* OK, we have a valid descriptor block which matches | |
453 | * all of the sequence number checks. What are we going | |
454 | * to do with it? That depends on the pass... */ | |
455 | ||
456 | switch(blocktype) { | |
f7f4bccb | 457 | case JBD2_DESCRIPTOR_BLOCK: |
470decc6 | 458 | /* If it is a valid descriptor block, replay it |
818d276c GS |
459 | * in pass REPLAY; if journal_checksums enabled, then |
460 | * calculate checksums in PASS_SCAN, otherwise, | |
461 | * just skip over the blocks it describes. */ | |
470decc6 | 462 | if (pass != PASS_REPLAY) { |
818d276c GS |
463 | if (pass == PASS_SCAN && |
464 | JBD2_HAS_COMPAT_FEATURE(journal, | |
465 | JBD2_FEATURE_COMPAT_CHECKSUM) && | |
466 | !info->end_transaction) { | |
467 | if (calc_chksums(journal, bh, | |
468 | &next_log_block, | |
469 | &crc32_sum)) { | |
470 | put_bh(bh); | |
471 | break; | |
472 | } | |
473 | put_bh(bh); | |
474 | continue; | |
475 | } | |
b517bea1 | 476 | next_log_block += count_tags(journal, bh); |
470decc6 | 477 | wrap(journal, next_log_block); |
818d276c | 478 | put_bh(bh); |
470decc6 DK |
479 | continue; |
480 | } | |
481 | ||
482 | /* A descriptor block: we can now write all of | |
483 | * the data blocks. Yay, useful work is finally | |
484 | * getting done here! */ | |
485 | ||
486 | tagp = &bh->b_data[sizeof(journal_header_t)]; | |
b517bea1 | 487 | while ((tagp - bh->b_data + tag_bytes) |
470decc6 DK |
488 | <= journal->j_blocksize) { |
489 | unsigned long io_block; | |
490 | ||
491 | tag = (journal_block_tag_t *) tagp; | |
492 | flags = be32_to_cpu(tag->t_flags); | |
493 | ||
494 | io_block = next_log_block++; | |
495 | wrap(journal, next_log_block); | |
496 | err = jread(&obh, journal, io_block); | |
497 | if (err) { | |
498 | /* Recover what we can, but | |
499 | * report failure at the end. */ | |
500 | success = err; | |
501 | printk (KERN_ERR | |
502 | "JBD: IO error %d recovering " | |
503 | "block %ld in log\n", | |
504 | err, io_block); | |
505 | } else { | |
18eba7aa | 506 | unsigned long long blocknr; |
470decc6 DK |
507 | |
508 | J_ASSERT(obh != NULL); | |
b517bea1 ZB |
509 | blocknr = read_tag_block(tag_bytes, |
510 | tag); | |
470decc6 DK |
511 | |
512 | /* If the block has been | |
513 | * revoked, then we're all done | |
514 | * here. */ | |
f7f4bccb | 515 | if (jbd2_journal_test_revoke |
470decc6 DK |
516 | (journal, blocknr, |
517 | next_commit_ID)) { | |
518 | brelse(obh); | |
519 | ++info->nr_revoke_hits; | |
520 | goto skip_write; | |
521 | } | |
522 | ||
523 | /* Find a buffer for the new | |
524 | * data being restored */ | |
525 | nbh = __getblk(journal->j_fs_dev, | |
526 | blocknr, | |
527 | journal->j_blocksize); | |
528 | if (nbh == NULL) { | |
529 | printk(KERN_ERR | |
530 | "JBD: Out of memory " | |
531 | "during recovery.\n"); | |
532 | err = -ENOMEM; | |
533 | brelse(bh); | |
534 | brelse(obh); | |
535 | goto failed; | |
536 | } | |
537 | ||
538 | lock_buffer(nbh); | |
539 | memcpy(nbh->b_data, obh->b_data, | |
540 | journal->j_blocksize); | |
f7f4bccb | 541 | if (flags & JBD2_FLAG_ESCAPE) { |
d0025676 | 542 | *((__be32 *)nbh->b_data) = |
f7f4bccb | 543 | cpu_to_be32(JBD2_MAGIC_NUMBER); |
470decc6 DK |
544 | } |
545 | ||
546 | BUFFER_TRACE(nbh, "marking dirty"); | |
547 | set_buffer_uptodate(nbh); | |
548 | mark_buffer_dirty(nbh); | |
549 | BUFFER_TRACE(nbh, "marking uptodate"); | |
550 | ++info->nr_replays; | |
551 | /* ll_rw_block(WRITE, 1, &nbh); */ | |
552 | unlock_buffer(nbh); | |
553 | brelse(obh); | |
554 | brelse(nbh); | |
555 | } | |
556 | ||
557 | skip_write: | |
b517bea1 | 558 | tagp += tag_bytes; |
f7f4bccb | 559 | if (!(flags & JBD2_FLAG_SAME_UUID)) |
470decc6 DK |
560 | tagp += 16; |
561 | ||
f7f4bccb | 562 | if (flags & JBD2_FLAG_LAST_TAG) |
470decc6 DK |
563 | break; |
564 | } | |
565 | ||
566 | brelse(bh); | |
567 | continue; | |
568 | ||
f7f4bccb | 569 | case JBD2_COMMIT_BLOCK: |
818d276c GS |
570 | /* How to differentiate between interrupted commit |
571 | * and journal corruption ? | |
572 | * | |
573 | * {nth transaction} | |
574 | * Checksum Verification Failed | |
575 | * | | |
576 | * ____________________ | |
577 | * | | | |
578 | * async_commit sync_commit | |
579 | * | | | |
580 | * | GO TO NEXT "Journal Corruption" | |
581 | * | TRANSACTION | |
582 | * | | |
583 | * {(n+1)th transanction} | |
584 | * | | |
585 | * _______|______________ | |
586 | * | | | |
587 | * Commit block found Commit block not found | |
588 | * | | | |
589 | * "Journal Corruption" | | |
590 | * _____________|_________ | |
591 | * | | | |
592 | * nth trans corrupt OR nth trans | |
593 | * and (n+1)th interrupted interrupted | |
594 | * before commit block | |
595 | * could reach the disk. | |
596 | * (Cannot find the difference in above | |
597 | * mentioned conditions. Hence assume | |
598 | * "Interrupted Commit".) | |
599 | */ | |
600 | ||
601 | /* Found an expected commit block: if checksums | |
602 | * are present verify them in PASS_SCAN; else not | |
603 | * much to do other than move on to the next sequence | |
470decc6 | 604 | * number. */ |
818d276c GS |
605 | if (pass == PASS_SCAN && |
606 | JBD2_HAS_COMPAT_FEATURE(journal, | |
607 | JBD2_FEATURE_COMPAT_CHECKSUM)) { | |
608 | int chksum_err, chksum_seen; | |
609 | struct commit_header *cbh = | |
610 | (struct commit_header *)bh->b_data; | |
611 | unsigned found_chksum = | |
612 | be32_to_cpu(cbh->h_chksum[0]); | |
613 | ||
614 | chksum_err = chksum_seen = 0; | |
615 | ||
616 | if (info->end_transaction) { | |
624080ed TT |
617 | journal->j_failed_commit = |
618 | info->end_transaction; | |
818d276c GS |
619 | brelse(bh); |
620 | break; | |
621 | } | |
622 | ||
623 | if (crc32_sum == found_chksum && | |
624 | cbh->h_chksum_type == JBD2_CRC32_CHKSUM && | |
625 | cbh->h_chksum_size == | |
626 | JBD2_CRC32_CHKSUM_SIZE) | |
627 | chksum_seen = 1; | |
628 | else if (!(cbh->h_chksum_type == 0 && | |
629 | cbh->h_chksum_size == 0 && | |
630 | found_chksum == 0 && | |
631 | !chksum_seen)) | |
632 | /* | |
633 | * If fs is mounted using an old kernel and then | |
634 | * kernel with journal_chksum is used then we | |
635 | * get a situation where the journal flag has | |
636 | * checksum flag set but checksums are not | |
637 | * present i.e chksum = 0, in the individual | |
638 | * commit blocks. | |
639 | * Hence to avoid checksum failures, in this | |
640 | * situation, this extra check is added. | |
641 | */ | |
642 | chksum_err = 1; | |
643 | ||
644 | if (chksum_err) { | |
645 | info->end_transaction = next_commit_ID; | |
646 | ||
4d605179 | 647 | if (!JBD2_HAS_INCOMPAT_FEATURE(journal, |
818d276c | 648 | JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)){ |
624080ed TT |
649 | journal->j_failed_commit = |
650 | next_commit_ID; | |
818d276c GS |
651 | brelse(bh); |
652 | break; | |
653 | } | |
654 | } | |
655 | crc32_sum = ~0; | |
656 | } | |
470decc6 DK |
657 | brelse(bh); |
658 | next_commit_ID++; | |
659 | continue; | |
660 | ||
f7f4bccb | 661 | case JBD2_REVOKE_BLOCK: |
470decc6 DK |
662 | /* 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 | ||
818d276c GS |
692 | if (pass == PASS_SCAN) { |
693 | if (!info->end_transaction) | |
694 | info->end_transaction = next_commit_ID; | |
695 | } else { | |
470decc6 DK |
696 | /* 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 | ||
716 | static int scan_revoke_records(journal_t *journal, struct buffer_head *bh, | |
717 | tid_t sequence, struct recovery_info *info) | |
718 | { | |
f7f4bccb | 719 | jbd2_journal_revoke_header_t *header; |
470decc6 | 720 | int offset, max; |
b517bea1 | 721 | int record_len = 4; |
470decc6 | 722 | |
f7f4bccb MC |
723 | header = (jbd2_journal_revoke_header_t *) bh->b_data; |
724 | offset = sizeof(jbd2_journal_revoke_header_t); | |
470decc6 DK |
725 | max = be32_to_cpu(header->r_count); |
726 | ||
b517bea1 ZB |
727 | if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT)) |
728 | record_len = 8; | |
729 | ||
730 | while (offset + record_len <= max) { | |
18eba7aa | 731 | unsigned long long blocknr; |
470decc6 DK |
732 | int err; |
733 | ||
b517bea1 ZB |
734 | 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; | |
f7f4bccb | 739 | err = jbd2_journal_set_revoke(journal, blocknr, sequence); |
470decc6 DK |
740 | if (err) |
741 | return err; | |
742 | ++info->nr_revokes; | |
743 | } | |
744 | return 0; | |
745 | } |