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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>
Jan Kara79feb522012-03-13 22:22:54 -040024#include <linux/blkdev.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) {
Eryu Guanf2a44522011-11-01 19:09:18 -040093 printk(KERN_ERR "JBD2: bad block at offset %u\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -070094 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) {
Eryu Guanf2a44522011-11-01 19:09:18 -0400142 printk(KERN_ERR "JBD2: corrupted journal superblock\n");
Dave Kleikamp470decc2006-10-11 01:20:57 -0700143 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) {
Eryu Guanf2a44522011-11-01 19:09:18 -0400149 printk(KERN_ERR "JBD2: bad block at offset %u\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -0700150 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)) {
Eryu Guanf2a44522011-11-01 19:09:18 -0400167 printk(KERN_ERR "JBD2: Failed to read block at offset %u\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -0700168 offset);
169 brelse(bh);
170 return -EIO;
171 }
172
173 *bhp = bh;
174 return 0;
175}
176
Darrick J. Wong3caa4872012-05-27 08:10:22 -0400177static int jbd2_descr_block_csum_verify(journal_t *j,
178 void *buf)
179{
180 struct jbd2_journal_block_tail *tail;
Darrick J. Wong18a6ea12013-08-28 14:59:58 -0400181 __be32 provided;
182 __u32 calculated;
Darrick J. Wong3caa4872012-05-27 08:10:22 -0400183
184 if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
185 return 1;
186
187 tail = (struct jbd2_journal_block_tail *)(buf + j->j_blocksize -
188 sizeof(struct jbd2_journal_block_tail));
189 provided = tail->t_checksum;
190 tail->t_checksum = 0;
191 calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
192 tail->t_checksum = provided;
193
Darrick J. Wong18a6ea12013-08-28 14:59:58 -0400194 return provided == cpu_to_be32(calculated);
Darrick J. Wong3caa4872012-05-27 08:10:22 -0400195}
Dave Kleikamp470decc2006-10-11 01:20:57 -0700196
197/*
198 * Count the number of in-use tags in a journal descriptor block.
199 */
200
Zach Brownb517bea2006-10-11 01:21:08 -0700201static int count_tags(journal_t *journal, struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700202{
203 char * tagp;
204 journal_block_tag_t * tag;
Zach Brownb517bea2006-10-11 01:21:08 -0700205 int nr = 0, size = journal->j_blocksize;
206 int tag_bytes = journal_tag_bytes(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700207
Darrick J. Wong3caa4872012-05-27 08:10:22 -0400208 if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
209 size -= sizeof(struct jbd2_journal_block_tail);
210
Dave Kleikamp470decc2006-10-11 01:20:57 -0700211 tagp = &bh->b_data[sizeof(journal_header_t)];
212
Zach Brownb517bea2006-10-11 01:21:08 -0700213 while ((tagp - bh->b_data + tag_bytes) <= size) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700214 tag = (journal_block_tag_t *) tagp;
215
216 nr++;
Zach Brownb517bea2006-10-11 01:21:08 -0700217 tagp += tag_bytes;
Darrick J. Wong8f888ef2012-05-22 22:43:41 -0400218 if (!(tag->t_flags & cpu_to_be16(JBD2_FLAG_SAME_UUID)))
Dave Kleikamp470decc2006-10-11 01:20:57 -0700219 tagp += 16;
220
Darrick J. Wong8f888ef2012-05-22 22:43:41 -0400221 if (tag->t_flags & cpu_to_be16(JBD2_FLAG_LAST_TAG))
Dave Kleikamp470decc2006-10-11 01:20:57 -0700222 break;
223 }
224
225 return nr;
226}
227
228
229/* Make sure we wrap around the log correctly! */
230#define wrap(journal, var) \
231do { \
232 if (var >= (journal)->j_last) \
233 var -= ((journal)->j_last - (journal)->j_first); \
234} while (0)
235
236/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700237 * jbd2_journal_recover - recovers a on-disk journal
Dave Kleikamp470decc2006-10-11 01:20:57 -0700238 * @journal: the journal to recover
239 *
240 * The primary function for recovering the log contents when mounting a
241 * journaled device.
242 *
243 * Recovery is done in three passes. In the first pass, we look for the
244 * end of the log. In the second, we assemble the list of revoke
245 * blocks. In the third and final pass, we replay any un-revoked blocks
246 * in the log.
247 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700248int jbd2_journal_recover(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700249{
Hidehiro Kawai44519fa2008-10-10 20:29:13 -0400250 int err, err2;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700251 journal_superblock_t * sb;
252
253 struct recovery_info info;
254
255 memset(&info, 0, sizeof(info));
256 sb = journal->j_superblock;
257
258 /*
259 * The journal superblock's s_start field (the current log head)
260 * is always zero if, and only if, the journal was cleanly
261 * unmounted.
262 */
263
264 if (!sb->s_start) {
265 jbd_debug(1, "No recovery required, last transaction %d\n",
266 be32_to_cpu(sb->s_sequence));
267 journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1;
268 return 0;
269 }
270
271 err = do_one_pass(journal, &info, PASS_SCAN);
272 if (!err)
273 err = do_one_pass(journal, &info, PASS_REVOKE);
274 if (!err)
275 err = do_one_pass(journal, &info, PASS_REPLAY);
276
Eryu Guanf2a44522011-11-01 19:09:18 -0400277 jbd_debug(1, "JBD2: recovery, exit status %d, "
Dave Kleikamp470decc2006-10-11 01:20:57 -0700278 "recovered transactions %u to %u\n",
279 err, info.start_transaction, info.end_transaction);
Eryu Guanf2a44522011-11-01 19:09:18 -0400280 jbd_debug(1, "JBD2: Replayed %d and revoked %d/%d blocks\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -0700281 info.nr_replays, info.nr_revoke_hits, info.nr_revokes);
282
283 /* Restart the log at the next transaction ID, thus invalidating
284 * any existing commit records in the log. */
285 journal->j_transaction_sequence = ++info.end_transaction;
286
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700287 jbd2_journal_clear_revoke(journal);
Hidehiro Kawai44519fa2008-10-10 20:29:13 -0400288 err2 = sync_blockdev(journal->j_fs_dev);
289 if (!err)
290 err = err2;
Jan Kara79feb522012-03-13 22:22:54 -0400291 /* Make sure all replayed data is on permanent storage */
Theodore Ts'o316e4cf2012-08-17 09:56:17 -0400292 if (journal->j_flags & JBD2_BARRIER) {
293 err2 = blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
294 if (!err)
295 err = err2;
296 }
Dave Kleikamp470decc2006-10-11 01:20:57 -0700297 return err;
298}
299
300/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700301 * jbd2_journal_skip_recovery - Start journal and wipe exiting records
Dave Kleikamp470decc2006-10-11 01:20:57 -0700302 * @journal: journal to startup
303 *
304 * Locate any valid recovery information from the journal and set up the
305 * journal structures in memory to ignore it (presumably because the
306 * caller has evidence that it is out of date).
307 * This function does'nt appear to be exorted..
308 *
309 * We perform one pass over the journal to allow us to tell the user how
310 * much recovery information is being erased, and to let us initialise
311 * the journal transaction sequence numbers to the next unused ID.
312 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700313int jbd2_journal_skip_recovery(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700314{
315 int err;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700316
317 struct recovery_info info;
318
319 memset (&info, 0, sizeof(info));
Dave Kleikamp470decc2006-10-11 01:20:57 -0700320
321 err = do_one_pass(journal, &info, PASS_SCAN);
322
323 if (err) {
Eryu Guanf2a44522011-11-01 19:09:18 -0400324 printk(KERN_ERR "JBD2: error %d scanning journal\n", err);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700325 ++journal->j_transaction_sequence;
326 } else {
Jose R. Santose23291b2007-07-18 08:57:06 -0400327#ifdef CONFIG_JBD2_DEBUG
Andi Kleen5a0790c2010-06-14 13:28:03 -0400328 int dropped = info.end_transaction -
329 be32_to_cpu(journal->j_superblock->s_sequence);
Mingming Caob38bd332007-07-19 01:48:35 -0700330 jbd_debug(1,
Eryu Guanf2a44522011-11-01 19:09:18 -0400331 "JBD2: ignoring %d transaction%s from the journal.\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -0700332 dropped, (dropped == 1) ? "" : "s");
Theodore Ts'o9a4f6272010-12-18 13:36:33 -0500333#endif
Dave Kleikamp470decc2006-10-11 01:20:57 -0700334 journal->j_transaction_sequence = ++info.end_transaction;
335 }
336
337 journal->j_tail = 0;
338 return err;
339}
340
Mingming Cao18eba7a2006-10-11 01:21:13 -0700341static inline unsigned long long read_tag_block(int tag_bytes, journal_block_tag_t *tag)
Zach Brownb517bea2006-10-11 01:21:08 -0700342{
Mingming Cao18eba7a2006-10-11 01:21:13 -0700343 unsigned long long block = be32_to_cpu(tag->t_blocknr);
Mingming Caocd02ff02007-10-16 18:38:25 -0400344 if (tag_bytes > JBD2_TAG_SIZE32)
Zach Brownb517bea2006-10-11 01:21:08 -0700345 block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32;
346 return block;
347}
348
Girish Shilamkar818d2762008-01-28 23:58:27 -0500349/*
350 * calc_chksums calculates the checksums for the blocks described in the
351 * descriptor block.
352 */
353static 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) {
Eryu Guanf2a44522011-11-01 19:09:18 -0400369 printk(KERN_ERR "JBD2: IO error %d recovering block "
Girish Shilamkar818d2762008-01-28 23:58:27 -0500370 "%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 }
Theodore Ts'o8ea76902008-05-26 10:28:09 -0400376 put_bh(obh);
Girish Shilamkar818d2762008-01-28 23:58:27 -0500377 }
378 return 0;
379}
380
Darrick J. Wong1f56c582012-05-27 08:10:25 -0400381static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
382{
383 struct commit_header *h;
Darrick J. Wong18a6ea12013-08-28 14:59:58 -0400384 __be32 provided;
385 __u32 calculated;
Darrick J. Wong1f56c582012-05-27 08:10:25 -0400386
387 if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
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
Darrick J. Wong18a6ea12013-08-28 14:59:58 -0400396 return provided == cpu_to_be32(calculated);
Darrick J. Wong1f56c582012-05-27 08:10:25 -0400397}
398
Darrick J. Wongc3900872012-05-27 08:12:12 -0400399static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
400 void *buf, __u32 sequence)
401{
Darrick J. Wongeee06c52013-05-28 07:31:59 -0400402 __u32 csum32;
Darrick J. Wong18a6ea12013-08-28 14:59:58 -0400403 __be32 seq;
Darrick J. Wongc3900872012-05-27 08:12:12 -0400404
405 if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
406 return 1;
407
Darrick J. Wong18a6ea12013-08-28 14:59:58 -0400408 seq = cpu_to_be32(sequence);
409 csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
Darrick J. Wongeee06c52013-05-28 07:31:59 -0400410 csum32 = jbd2_chksum(j, csum32, buf, j->j_blocksize);
Darrick J. Wongc3900872012-05-27 08:12:12 -0400411
Darrick J. Wongeee06c52013-05-28 07:31:59 -0400412 return tag->t_checksum == cpu_to_be16(csum32);
Darrick J. Wongc3900872012-05-27 08:12:12 -0400413}
414
Dave Kleikamp470decc2006-10-11 01:20:57 -0700415static int do_one_pass(journal_t *journal,
416 struct recovery_info *info, enum passtype pass)
417{
418 unsigned int first_commit_ID, next_commit_ID;
419 unsigned long next_log_block;
420 int err, success = 0;
421 journal_superblock_t * sb;
422 journal_header_t * tmp;
423 struct buffer_head * bh;
424 unsigned int sequence;
425 int blocktype;
Zach Brownb517bea2006-10-11 01:21:08 -0700426 int tag_bytes = journal_tag_bytes(journal);
Girish Shilamkar818d2762008-01-28 23:58:27 -0500427 __u32 crc32_sum = ~0; /* Transactional Checksums */
Darrick J. Wong3caa4872012-05-27 08:10:22 -0400428 int descr_csum_size = 0;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700429
Dave Kleikamp470decc2006-10-11 01:20:57 -0700430 /*
431 * First thing is to establish what we expect to find in the log
432 * (in terms of transaction IDs), and where (in terms of log
433 * block offsets): query the superblock.
434 */
435
436 sb = journal->j_superblock;
437 next_commit_ID = be32_to_cpu(sb->s_sequence);
438 next_log_block = be32_to_cpu(sb->s_start);
439
440 first_commit_ID = next_commit_ID;
441 if (pass == PASS_SCAN)
442 info->start_transaction = first_commit_ID;
443
444 jbd_debug(1, "Starting recovery pass %d\n", pass);
445
446 /*
447 * Now we walk through the log, transaction by transaction,
448 * making sure that each transaction has a commit block in the
449 * expected place. Each complete transaction gets replayed back
450 * into the main filesystem.
451 */
452
453 while (1) {
454 int flags;
455 char * tagp;
456 journal_block_tag_t * tag;
457 struct buffer_head * obh;
458 struct buffer_head * nbh;
459
Andi Kleene86e1432008-02-06 01:40:11 -0800460 cond_resched();
Dave Kleikamp470decc2006-10-11 01:20:57 -0700461
462 /* If we already know where to stop the log traversal,
463 * check right now that we haven't gone past the end of
464 * the log. */
465
466 if (pass != PASS_SCAN)
467 if (tid_geq(next_commit_ID, info->end_transaction))
468 break;
469
470 jbd_debug(2, "Scanning for sequence ID %u at %lu/%lu\n",
471 next_commit_ID, next_log_block, journal->j_last);
472
473 /* Skip over each chunk of the transaction looking
474 * either the next descriptor block or the final commit
475 * record. */
476
Eryu Guanf2a44522011-11-01 19:09:18 -0400477 jbd_debug(3, "JBD2: checking block %ld\n", next_log_block);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700478 err = jread(&bh, journal, next_log_block);
479 if (err)
480 goto failed;
481
482 next_log_block++;
483 wrap(journal, next_log_block);
484
485 /* What kind of buffer is it?
486 *
487 * If it is a descriptor block, check that it has the
488 * expected sequence number. Otherwise, we're all done
489 * here. */
490
491 tmp = (journal_header_t *)bh->b_data;
492
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700493 if (tmp->h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER)) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700494 brelse(bh);
495 break;
496 }
497
498 blocktype = be32_to_cpu(tmp->h_blocktype);
499 sequence = be32_to_cpu(tmp->h_sequence);
500 jbd_debug(3, "Found magic %d, sequence %d\n",
501 blocktype, sequence);
502
503 if (sequence != next_commit_ID) {
504 brelse(bh);
505 break;
506 }
507
508 /* OK, we have a valid descriptor block which matches
509 * all of the sequence number checks. What are we going
510 * to do with it? That depends on the pass... */
511
512 switch(blocktype) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700513 case JBD2_DESCRIPTOR_BLOCK:
Darrick J. Wong3caa4872012-05-27 08:10:22 -0400514 /* Verify checksum first */
515 if (JBD2_HAS_INCOMPAT_FEATURE(journal,
516 JBD2_FEATURE_INCOMPAT_CSUM_V2))
517 descr_csum_size =
518 sizeof(struct jbd2_journal_block_tail);
519 if (descr_csum_size > 0 &&
520 !jbd2_descr_block_csum_verify(journal,
521 bh->b_data)) {
522 err = -EIO;
523 goto failed;
524 }
525
Dave Kleikamp470decc2006-10-11 01:20:57 -0700526 /* If it is a valid descriptor block, replay it
Girish Shilamkar818d2762008-01-28 23:58:27 -0500527 * in pass REPLAY; if journal_checksums enabled, then
528 * calculate checksums in PASS_SCAN, otherwise,
529 * just skip over the blocks it describes. */
Dave Kleikamp470decc2006-10-11 01:20:57 -0700530 if (pass != PASS_REPLAY) {
Girish Shilamkar818d2762008-01-28 23:58:27 -0500531 if (pass == PASS_SCAN &&
532 JBD2_HAS_COMPAT_FEATURE(journal,
533 JBD2_FEATURE_COMPAT_CHECKSUM) &&
534 !info->end_transaction) {
535 if (calc_chksums(journal, bh,
536 &next_log_block,
537 &crc32_sum)) {
538 put_bh(bh);
539 break;
540 }
541 put_bh(bh);
542 continue;
543 }
Zach Brownb517bea2006-10-11 01:21:08 -0700544 next_log_block += count_tags(journal, bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700545 wrap(journal, next_log_block);
Girish Shilamkar818d2762008-01-28 23:58:27 -0500546 put_bh(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700547 continue;
548 }
549
550 /* A descriptor block: we can now write all of
551 * the data blocks. Yay, useful work is finally
552 * getting done here! */
553
554 tagp = &bh->b_data[sizeof(journal_header_t)];
Zach Brownb517bea2006-10-11 01:21:08 -0700555 while ((tagp - bh->b_data + tag_bytes)
Darrick J. Wong3caa4872012-05-27 08:10:22 -0400556 <= journal->j_blocksize - descr_csum_size) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700557 unsigned long io_block;
558
559 tag = (journal_block_tag_t *) tagp;
Darrick J. Wong8f888ef2012-05-22 22:43:41 -0400560 flags = be16_to_cpu(tag->t_flags);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700561
562 io_block = next_log_block++;
563 wrap(journal, next_log_block);
564 err = jread(&obh, journal, io_block);
565 if (err) {
566 /* Recover what we can, but
567 * report failure at the end. */
568 success = err;
Eryu Guanf2a44522011-11-01 19:09:18 -0400569 printk(KERN_ERR
570 "JBD2: IO error %d recovering "
Dave Kleikamp470decc2006-10-11 01:20:57 -0700571 "block %ld in log\n",
572 err, io_block);
573 } else {
Mingming Cao18eba7a2006-10-11 01:21:13 -0700574 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700575
576 J_ASSERT(obh != NULL);
Zach Brownb517bea2006-10-11 01:21:08 -0700577 blocknr = read_tag_block(tag_bytes,
578 tag);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700579
580 /* If the block has been
581 * revoked, then we're all done
582 * here. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700583 if (jbd2_journal_test_revoke
Dave Kleikamp470decc2006-10-11 01:20:57 -0700584 (journal, blocknr,
585 next_commit_ID)) {
586 brelse(obh);
587 ++info->nr_revoke_hits;
588 goto skip_write;
589 }
590
Darrick J. Wongc3900872012-05-27 08:12:12 -0400591 /* Look for block corruption */
592 if (!jbd2_block_tag_csum_verify(
593 journal, tag, obh->b_data,
594 be32_to_cpu(tmp->h_sequence))) {
595 brelse(obh);
596 success = -EIO;
Dmitry Monakhova67c8482013-12-08 21:14:59 -0500597 printk(KERN_ERR "JBD2: Invalid "
Darrick J. Wongc3900872012-05-27 08:12:12 -0400598 "checksum recovering "
599 "block %llu in log\n",
600 blocknr);
601 continue;
602 }
603
Dave Kleikamp470decc2006-10-11 01:20:57 -0700604 /* Find a buffer for the new
605 * data being restored */
606 nbh = __getblk(journal->j_fs_dev,
607 blocknr,
608 journal->j_blocksize);
609 if (nbh == NULL) {
610 printk(KERN_ERR
Eryu Guanf2a44522011-11-01 19:09:18 -0400611 "JBD2: Out of memory "
Dave Kleikamp470decc2006-10-11 01:20:57 -0700612 "during recovery.\n");
613 err = -ENOMEM;
614 brelse(bh);
615 brelse(obh);
616 goto failed;
617 }
618
619 lock_buffer(nbh);
620 memcpy(nbh->b_data, obh->b_data,
621 journal->j_blocksize);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700622 if (flags & JBD2_FLAG_ESCAPE) {
Duane Griffind0025672008-03-19 17:00:54 -0700623 *((__be32 *)nbh->b_data) =
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700624 cpu_to_be32(JBD2_MAGIC_NUMBER);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700625 }
626
627 BUFFER_TRACE(nbh, "marking dirty");
628 set_buffer_uptodate(nbh);
629 mark_buffer_dirty(nbh);
630 BUFFER_TRACE(nbh, "marking uptodate");
631 ++info->nr_replays;
632 /* ll_rw_block(WRITE, 1, &nbh); */
633 unlock_buffer(nbh);
634 brelse(obh);
635 brelse(nbh);
636 }
637
638 skip_write:
Zach Brownb517bea2006-10-11 01:21:08 -0700639 tagp += tag_bytes;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700640 if (!(flags & JBD2_FLAG_SAME_UUID))
Dave Kleikamp470decc2006-10-11 01:20:57 -0700641 tagp += 16;
642
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700643 if (flags & JBD2_FLAG_LAST_TAG)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700644 break;
645 }
646
647 brelse(bh);
648 continue;
649
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700650 case JBD2_COMMIT_BLOCK:
Girish Shilamkar818d2762008-01-28 23:58:27 -0500651 /* How to differentiate between interrupted commit
652 * and journal corruption ?
653 *
654 * {nth transaction}
655 * Checksum Verification Failed
656 * |
657 * ____________________
658 * | |
659 * async_commit sync_commit
660 * | |
661 * | GO TO NEXT "Journal Corruption"
662 * | TRANSACTION
663 * |
664 * {(n+1)th transanction}
665 * |
666 * _______|______________
667 * | |
668 * Commit block found Commit block not found
669 * | |
670 * "Journal Corruption" |
671 * _____________|_________
672 * | |
673 * nth trans corrupt OR nth trans
674 * and (n+1)th interrupted interrupted
675 * before commit block
676 * could reach the disk.
677 * (Cannot find the difference in above
678 * mentioned conditions. Hence assume
679 * "Interrupted Commit".)
680 */
681
682 /* Found an expected commit block: if checksums
683 * are present verify them in PASS_SCAN; else not
684 * much to do other than move on to the next sequence
Dave Kleikamp470decc2006-10-11 01:20:57 -0700685 * number. */
Girish Shilamkar818d2762008-01-28 23:58:27 -0500686 if (pass == PASS_SCAN &&
687 JBD2_HAS_COMPAT_FEATURE(journal,
688 JBD2_FEATURE_COMPAT_CHECKSUM)) {
689 int chksum_err, chksum_seen;
690 struct commit_header *cbh =
691 (struct commit_header *)bh->b_data;
692 unsigned found_chksum =
693 be32_to_cpu(cbh->h_chksum[0]);
694
695 chksum_err = chksum_seen = 0;
696
697 if (info->end_transaction) {
Theodore Ts'o624080e2008-06-06 17:50:40 -0400698 journal->j_failed_commit =
699 info->end_transaction;
Girish Shilamkar818d2762008-01-28 23:58:27 -0500700 brelse(bh);
701 break;
702 }
703
704 if (crc32_sum == found_chksum &&
705 cbh->h_chksum_type == JBD2_CRC32_CHKSUM &&
706 cbh->h_chksum_size ==
707 JBD2_CRC32_CHKSUM_SIZE)
708 chksum_seen = 1;
709 else if (!(cbh->h_chksum_type == 0 &&
710 cbh->h_chksum_size == 0 &&
711 found_chksum == 0 &&
712 !chksum_seen))
713 /*
714 * If fs is mounted using an old kernel and then
715 * kernel with journal_chksum is used then we
716 * get a situation where the journal flag has
717 * checksum flag set but checksums are not
718 * present i.e chksum = 0, in the individual
719 * commit blocks.
720 * Hence to avoid checksum failures, in this
721 * situation, this extra check is added.
722 */
723 chksum_err = 1;
724
725 if (chksum_err) {
726 info->end_transaction = next_commit_ID;
727
Aneesh Kumar K.V4d605172008-02-05 10:56:15 -0500728 if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
Girish Shilamkar818d2762008-01-28 23:58:27 -0500729 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)){
Theodore Ts'o624080e2008-06-06 17:50:40 -0400730 journal->j_failed_commit =
731 next_commit_ID;
Girish Shilamkar818d2762008-01-28 23:58:27 -0500732 brelse(bh);
733 break;
734 }
735 }
736 crc32_sum = ~0;
737 }
Darrick J. Wong1f56c582012-05-27 08:10:25 -0400738 if (pass == PASS_SCAN &&
739 !jbd2_commit_block_csum_verify(journal,
740 bh->b_data)) {
741 info->end_transaction = next_commit_ID;
742
743 if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
744 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
745 journal->j_failed_commit =
746 next_commit_ID;
747 brelse(bh);
748 break;
749 }
750 }
Dave Kleikamp470decc2006-10-11 01:20:57 -0700751 brelse(bh);
752 next_commit_ID++;
753 continue;
754
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700755 case JBD2_REVOKE_BLOCK:
Dave Kleikamp470decc2006-10-11 01:20:57 -0700756 /* If we aren't in the REVOKE pass, then we can
757 * just skip over this block. */
758 if (pass != PASS_REVOKE) {
759 brelse(bh);
760 continue;
761 }
762
763 err = scan_revoke_records(journal, bh,
764 next_commit_ID, info);
765 brelse(bh);
766 if (err)
767 goto failed;
768 continue;
769
770 default:
771 jbd_debug(3, "Unrecognised magic %d, end of scan.\n",
772 blocktype);
773 brelse(bh);
774 goto done;
775 }
776 }
777
778 done:
779 /*
780 * We broke out of the log scan loop: either we came to the
781 * known end of the log or we found an unexpected block in the
782 * log. If the latter happened, then we know that the "current"
783 * transaction marks the end of the valid log.
784 */
785
Girish Shilamkar818d2762008-01-28 23:58:27 -0500786 if (pass == PASS_SCAN) {
787 if (!info->end_transaction)
788 info->end_transaction = next_commit_ID;
789 } else {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700790 /* It's really bad news if different passes end up at
791 * different places (but possible due to IO errors). */
792 if (info->end_transaction != next_commit_ID) {
Eryu Guanf2a44522011-11-01 19:09:18 -0400793 printk(KERN_ERR "JBD2: recovery pass %d ended at "
Dave Kleikamp470decc2006-10-11 01:20:57 -0700794 "transaction %u, expected %u\n",
795 pass, next_commit_ID, info->end_transaction);
796 if (!success)
797 success = -EIO;
798 }
799 }
800
801 return success;
802
803 failed:
804 return err;
805}
806
Darrick J. Wong42a71062012-05-27 08:08:24 -0400807static int jbd2_revoke_block_csum_verify(journal_t *j,
808 void *buf)
809{
810 struct jbd2_journal_revoke_tail *tail;
Darrick J. Wong18a6ea12013-08-28 14:59:58 -0400811 __be32 provided;
812 __u32 calculated;
Darrick J. Wong42a71062012-05-27 08:08:24 -0400813
814 if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
815 return 1;
816
817 tail = (struct jbd2_journal_revoke_tail *)(buf + j->j_blocksize -
818 sizeof(struct jbd2_journal_revoke_tail));
819 provided = tail->r_checksum;
820 tail->r_checksum = 0;
821 calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
822 tail->r_checksum = provided;
823
Darrick J. Wong18a6ea12013-08-28 14:59:58 -0400824 return provided == cpu_to_be32(calculated);
Darrick J. Wong42a71062012-05-27 08:08:24 -0400825}
Dave Kleikamp470decc2006-10-11 01:20:57 -0700826
827/* Scan a revoke record, marking all blocks mentioned as revoked. */
828
829static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
830 tid_t sequence, struct recovery_info *info)
831{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700832 jbd2_journal_revoke_header_t *header;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700833 int offset, max;
Zach Brownb517bea2006-10-11 01:21:08 -0700834 int record_len = 4;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700835
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700836 header = (jbd2_journal_revoke_header_t *) bh->b_data;
837 offset = sizeof(jbd2_journal_revoke_header_t);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700838 max = be32_to_cpu(header->r_count);
839
Darrick J. Wong42a71062012-05-27 08:08:24 -0400840 if (!jbd2_revoke_block_csum_verify(journal, header))
841 return -EINVAL;
842
Zach Brownb517bea2006-10-11 01:21:08 -0700843 if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
844 record_len = 8;
845
846 while (offset + record_len <= max) {
Mingming Cao18eba7a2006-10-11 01:21:13 -0700847 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700848 int err;
849
Zach Brownb517bea2006-10-11 01:21:08 -0700850 if (record_len == 4)
851 blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset)));
852 else
853 blocknr = be64_to_cpu(* ((__be64 *) (bh->b_data+offset)));
854 offset += record_len;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700855 err = jbd2_journal_set_revoke(journal, blocknr, sequence);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700856 if (err)
857 return err;
858 ++info->nr_revokes;
859 }
860 return 0;
861}