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1 /*
2  * do_journal.c --- Scribble onto the journal!
3  *
4  * Copyright (C) 2014 Oracle.  This file may be redistributed
5  * under the terms of the GNU Public License.
6  */
7 
8 #include "config.h"
9 #include <stdio.h>
10 #ifdef HAVE_GETOPT_H
11 #include <getopt.h>
12 #else
13 extern int optind;
14 extern char *optarg;
15 #endif
16 #include <ctype.h>
17 #include <unistd.h>
18 #ifdef HAVE_SYS_TIME_H
19 #include <sys/time.h>
20 #endif
21 
22 #include "debugfs.h"
23 #include "ext2fs/kernel-jbd.h"
24 #include "journal.h"
25 
26 #undef DEBUG
27 
28 #ifdef DEBUG
29 # define dbg_printf(f, a...)  do {printf("JFS DEBUG: " f, ## a); \
30 	fflush(stdout); \
31 } while (0)
32 #else
33 # define dbg_printf(f, a...)
34 #endif
35 
36 #define JOURNAL_CHECK_TRANS_MAGIC(x)	\
37 	do { \
38 		if ((x)->magic != J_TRANS_MAGIC) \
39 			return EXT2_ET_INVALID_ARGUMENT; \
40 	} while (0)
41 
42 #define J_TRANS_MAGIC		0xD15EA5ED
43 #define J_TRANS_OPEN		1
44 #define J_TRANS_COMMITTED	2
45 struct journal_transaction_s {
46 	unsigned int magic;
47 	ext2_filsys fs;
48 	journal_t *journal;
49 	blk64_t block;
50 	blk64_t start, end;
51 	tid_t tid;
52 	int flags;
53 };
54 
55 typedef struct journal_transaction_s journal_transaction_t;
56 
57 static journal_t *current_journal = NULL;
58 
journal_dump_trans(journal_transaction_t * trans EXT2FS_ATTR ((unused)),const char * tag EXT2FS_ATTR ((unused)))59 static void journal_dump_trans(journal_transaction_t *trans EXT2FS_ATTR((unused)),
60 			       const char *tag EXT2FS_ATTR((unused)))
61 {
62 	dbg_printf("TRANS %p(%s): tid=%d start=%llu block=%llu end=%llu "
63 		   "flags=0x%x\n", trans, tag, trans->tid, trans->start,
64 		   trans->block, trans->end, trans->flags);
65 }
66 
journal_commit_trans(journal_transaction_t * trans)67 static errcode_t journal_commit_trans(journal_transaction_t *trans)
68 {
69 	struct buffer_head *bh, *cbh = NULL;
70 	struct commit_header *commit;
71 #ifdef HAVE_SYS_TIME_H
72 	struct timeval tv;
73 #endif
74 	errcode_t err;
75 
76 	JOURNAL_CHECK_TRANS_MAGIC(trans);
77 
78 	if ((trans->flags & J_TRANS_COMMITTED) ||
79 	    !(trans->flags & J_TRANS_OPEN))
80 		return EXT2_ET_INVALID_ARGUMENT;
81 
82 	bh = getblk(trans->journal->j_dev, 0, trans->journal->j_blocksize);
83 	if (bh == NULL)
84 		return ENOMEM;
85 
86 	/* write the descriptor block header */
87 	commit = (struct commit_header *)bh->b_data;
88 	commit->h_magic = ext2fs_cpu_to_be32(JFS_MAGIC_NUMBER);
89 	commit->h_blocktype = ext2fs_cpu_to_be32(JFS_COMMIT_BLOCK);
90 	commit->h_sequence = ext2fs_cpu_to_be32(trans->tid);
91 	if (jfs_has_feature_checksum(trans->journal)) {
92 		__u32 csum_v1 = ~0;
93 		blk64_t cblk;
94 
95 		cbh = getblk(trans->journal->j_dev, 0,
96 			     trans->journal->j_blocksize);
97 		if (cbh == NULL) {
98 			err = ENOMEM;
99 			goto error;
100 		}
101 
102 		for (cblk = trans->start; cblk < trans->block; cblk++) {
103 			err = journal_bmap(trans->journal, cblk,
104 					   &cbh->b_blocknr);
105 			if (err)
106 				goto error;
107 			mark_buffer_uptodate(cbh, 0);
108 			ll_rw_block(READ, 1, &cbh);
109 			err = cbh->b_err;
110 			if (err)
111 				goto error;
112 			csum_v1 = ext2fs_crc32_be(csum_v1,
113 					(unsigned char const *)cbh->b_data,
114 					cbh->b_size);
115 		}
116 
117 		commit->h_chksum_type = JFS_CRC32_CHKSUM;
118 		commit->h_chksum_size = JFS_CRC32_CHKSUM_SIZE;
119 		commit->h_chksum[0] = ext2fs_cpu_to_be32(csum_v1);
120 	} else {
121 		commit->h_chksum_type = 0;
122 		commit->h_chksum_size = 0;
123 		commit->h_chksum[0] = 0;
124 	}
125 #ifdef HAVE_SYS_TIME_H
126 	gettimeofday(&tv, NULL);
127 	commit->h_commit_sec = ext2fs_cpu_to_be32(tv.tv_sec);
128 	commit->h_commit_nsec = ext2fs_cpu_to_be32(tv.tv_usec * 1000);
129 #else
130 	commit->h_commit_sec = 0;
131 	commit->h_commit_nsec = 0;
132 #endif
133 
134 	/* Write block */
135 	jbd2_commit_block_csum_set(trans->journal, bh);
136 	err = journal_bmap(trans->journal, trans->block, &bh->b_blocknr);
137 	if (err)
138 		goto error;
139 
140 	dbg_printf("Writing commit block at %llu:%llu\n", trans->block,
141 		   bh->b_blocknr);
142 	mark_buffer_dirty(bh);
143 	ll_rw_block(WRITE, 1, &bh);
144 	err = bh->b_err;
145 	if (err)
146 		goto error;
147 	trans->flags |= J_TRANS_COMMITTED;
148 	trans->flags &= ~J_TRANS_OPEN;
149 	trans->block++;
150 
151 	ext2fs_set_feature_journal_needs_recovery(trans->fs->super);
152 	ext2fs_mark_super_dirty(trans->fs);
153 error:
154 	if (cbh)
155 		brelse(cbh);
156 	brelse(bh);
157 	return err;
158 }
159 
journal_add_revoke_to_trans(journal_transaction_t * trans,blk64_t * revoke_list,size_t revoke_len)160 static errcode_t journal_add_revoke_to_trans(journal_transaction_t *trans,
161 					     blk64_t *revoke_list,
162 					     size_t revoke_len)
163 {
164 	journal_revoke_header_t *jrb;
165 	void *buf;
166 	size_t i, offset;
167 	blk64_t curr_blk;
168 	unsigned int sz;
169 	unsigned csum_size = 0;
170 	struct buffer_head *bh;
171 	errcode_t err;
172 
173 	JOURNAL_CHECK_TRANS_MAGIC(trans);
174 
175 	if ((trans->flags & J_TRANS_COMMITTED) ||
176 	    !(trans->flags & J_TRANS_OPEN))
177 		return EXT2_ET_INVALID_ARGUMENT;
178 
179 	if (revoke_len == 0)
180 		return 0;
181 
182 	/* Do we need to leave space at the end for a checksum? */
183 	if (journal_has_csum_v2or3(trans->journal))
184 		csum_size = sizeof(struct journal_revoke_tail);
185 
186 	curr_blk = trans->block;
187 
188 	bh = getblk(trans->journal->j_dev, curr_blk,
189 		    trans->journal->j_blocksize);
190 	if (bh == NULL)
191 		return ENOMEM;
192 	jrb = buf = bh->b_data;
193 	jrb->r_header.h_magic = ext2fs_cpu_to_be32(JFS_MAGIC_NUMBER);
194 	jrb->r_header.h_blocktype = ext2fs_cpu_to_be32(JFS_REVOKE_BLOCK);
195 	jrb->r_header.h_sequence = ext2fs_cpu_to_be32(trans->tid);
196 	offset = sizeof(*jrb);
197 
198 	if (jfs_has_feature_64bit(trans->journal))
199 		sz = 8;
200 	else
201 		sz = 4;
202 
203 	for (i = 0; i < revoke_len; i++) {
204 		/* Block full, write to journal */
205 		if (offset + sz > trans->journal->j_blocksize - csum_size) {
206 			jrb->r_count = ext2fs_cpu_to_be32(offset);
207 			jbd2_revoke_csum_set(trans->journal, bh);
208 
209 			err = journal_bmap(trans->journal, curr_blk,
210 					   &bh->b_blocknr);
211 			if (err)
212 				goto error;
213 			dbg_printf("Writing revoke block at %llu:%llu\n",
214 				   curr_blk, bh->b_blocknr);
215 			mark_buffer_dirty(bh);
216 			ll_rw_block(WRITE, 1, &bh);
217 			err = bh->b_err;
218 			if (err)
219 				goto error;
220 
221 			offset = sizeof(*jrb);
222 			curr_blk++;
223 		}
224 
225 		if (revoke_list[i] >=
226 		    ext2fs_blocks_count(trans->journal->j_fs_dev->k_fs->super)) {
227 			err = EXT2_ET_BAD_BLOCK_NUM;
228 			goto error;
229 		}
230 
231 		if (jfs_has_feature_64bit(trans->journal))
232 			*((__u64 *)(&((char *)buf)[offset])) =
233 				ext2fs_cpu_to_be64(revoke_list[i]);
234 		else
235 			*((__u32 *)(&((char *)buf)[offset])) =
236 				ext2fs_cpu_to_be32(revoke_list[i]);
237 		offset += sz;
238 	}
239 
240 	if (offset > 0) {
241 		jrb->r_count = ext2fs_cpu_to_be32(offset);
242 		jbd2_revoke_csum_set(trans->journal, bh);
243 
244 		err = journal_bmap(trans->journal, curr_blk, &bh->b_blocknr);
245 		if (err)
246 			goto error;
247 		dbg_printf("Writing revoke block at %llu:%llu\n",
248 			   curr_blk, bh->b_blocknr);
249 		mark_buffer_dirty(bh);
250 		ll_rw_block(WRITE, 1, &bh);
251 		err = bh->b_err;
252 		if (err)
253 			goto error;
254 		curr_blk++;
255 	}
256 
257 error:
258 	trans->block = curr_blk;
259 	brelse(bh);
260 	return err;
261 }
262 
journal_add_blocks_to_trans(journal_transaction_t * trans,blk64_t * block_list,size_t block_len,FILE * fp)263 static errcode_t journal_add_blocks_to_trans(journal_transaction_t *trans,
264 				      blk64_t *block_list, size_t block_len,
265 				      FILE *fp)
266 {
267 	blk64_t curr_blk, jdb_blk;
268 	size_t i, j;
269 	int csum_size = 0;
270 	journal_header_t *jdb;
271 	journal_block_tag_t *jdbt;
272 	int tag_bytes;
273 	void *buf = NULL, *jdb_buf = NULL;
274 	struct buffer_head *bh = NULL, *data_bh;
275 	errcode_t err;
276 
277 	JOURNAL_CHECK_TRANS_MAGIC(trans);
278 
279 	if ((trans->flags & J_TRANS_COMMITTED) ||
280 	    !(trans->flags & J_TRANS_OPEN))
281 		return EXT2_ET_INVALID_ARGUMENT;
282 
283 	if (block_len == 0)
284 		return 0;
285 
286 	/* Do we need to leave space at the end for a checksum? */
287 	if (journal_has_csum_v2or3(trans->journal))
288 		csum_size = sizeof(struct journal_block_tail);
289 
290 	curr_blk = jdb_blk = trans->block;
291 
292 	data_bh = getblk(trans->journal->j_dev, curr_blk,
293 			 trans->journal->j_blocksize);
294 	if (data_bh == NULL)
295 		return ENOMEM;
296 	buf = data_bh->b_data;
297 
298 	/* write the descriptor block header */
299 	bh = getblk(trans->journal->j_dev, curr_blk,
300 		    trans->journal->j_blocksize);
301 	if (bh == NULL) {
302 		err = ENOMEM;
303 		goto error;
304 	}
305 	jdb = jdb_buf = bh->b_data;
306 	jdb->h_magic = ext2fs_cpu_to_be32(JFS_MAGIC_NUMBER);
307 	jdb->h_blocktype = ext2fs_cpu_to_be32(JFS_DESCRIPTOR_BLOCK);
308 	jdb->h_sequence = ext2fs_cpu_to_be32(trans->tid);
309 	jdbt = (journal_block_tag_t *)(jdb + 1);
310 
311 	curr_blk++;
312 	for (i = 0; i < block_len; i++) {
313 		j = fread(data_bh->b_data, trans->journal->j_blocksize, 1, fp);
314 		if (j != 1) {
315 			err = errno;
316 			goto error;
317 		}
318 
319 		tag_bytes = journal_tag_bytes(trans->journal);
320 
321 		/* No space left in descriptor block, write it out */
322 		if ((char *)jdbt + tag_bytes >
323 		    (char *)jdb_buf + trans->journal->j_blocksize - csum_size) {
324 			jbd2_descr_block_csum_set(trans->journal, bh);
325 			err = journal_bmap(trans->journal, jdb_blk,
326 					   &bh->b_blocknr);
327 			if (err)
328 				goto error;
329 			dbg_printf("Writing descriptor block at %llu:%llu\n",
330 				   jdb_blk, bh->b_blocknr);
331 			mark_buffer_dirty(bh);
332 			ll_rw_block(WRITE, 1, &bh);
333 			err = bh->b_err;
334 			if (err)
335 				goto error;
336 
337 			jdbt = (journal_block_tag_t *)(jdb + 1);
338 			jdb_blk = curr_blk;
339 			curr_blk++;
340 		}
341 
342 		if (block_list[i] >=
343 		    ext2fs_blocks_count(trans->journal->j_fs_dev->k_fs->super)) {
344 			err = EXT2_ET_BAD_BLOCK_NUM;
345 			goto error;
346 		}
347 
348 		/* Fill out the block tag */
349 		jdbt->t_blocknr = ext2fs_cpu_to_be32(block_list[i] & 0xFFFFFFFF);
350 		jdbt->t_flags = 0;
351 		if (jdbt != (journal_block_tag_t *)(jdb + 1))
352 			jdbt->t_flags |= ext2fs_cpu_to_be16(JFS_FLAG_SAME_UUID);
353 		else {
354 			memcpy(jdbt + tag_bytes,
355 			       trans->journal->j_superblock->s_uuid,
356 			       sizeof(trans->journal->j_superblock->s_uuid));
357 			tag_bytes += 16;
358 		}
359 		if (i == block_len - 1)
360 			jdbt->t_flags |= ext2fs_cpu_to_be16(JFS_FLAG_LAST_TAG);
361 		if (*((__u32 *)buf) == ext2fs_cpu_to_be32(JFS_MAGIC_NUMBER)) {
362 			*((__u32 *)buf) = 0;
363 			jdbt->t_flags |= ext2fs_cpu_to_be16(JFS_FLAG_ESCAPE);
364 		}
365 		if (jfs_has_feature_64bit(trans->journal))
366 			jdbt->t_blocknr_high = ext2fs_cpu_to_be32(block_list[i] >> 32);
367 		jbd2_block_tag_csum_set(trans->journal, jdbt, data_bh,
368 					trans->tid);
369 
370 		/* Write the data block */
371 		err = journal_bmap(trans->journal, curr_blk,
372 				   &data_bh->b_blocknr);
373 		if (err)
374 			goto error;
375 		dbg_printf("Writing data block %llu at %llu:%llu tag %d\n",
376 			   block_list[i], curr_blk, data_bh->b_blocknr,
377 			   tag_bytes);
378 		mark_buffer_dirty(data_bh);
379 		ll_rw_block(WRITE, 1, &data_bh);
380 		err = data_bh->b_err;
381 		if (err)
382 			goto error;
383 
384 		curr_blk++;
385 		jdbt = (journal_block_tag_t *)(((char *)jdbt) + tag_bytes);
386 	}
387 
388 	/* Write out the last descriptor block */
389 	if (jdbt != (journal_block_tag_t *)(jdb + 1)) {
390 		jbd2_descr_block_csum_set(trans->journal, bh);
391 		err = journal_bmap(trans->journal, jdb_blk, &bh->b_blocknr);
392 		if (err)
393 			goto error;
394 		dbg_printf("Writing descriptor block at %llu:%llu\n",
395 			   jdb_blk, bh->b_blocknr);
396 		mark_buffer_dirty(bh);
397 		ll_rw_block(WRITE, 1, &bh);
398 		err = bh->b_err;
399 		if (err)
400 			goto error;
401 	}
402 
403 error:
404 	trans->block = curr_blk;
405 	if (bh)
406 		brelse(bh);
407 	brelse(data_bh);
408 	return err;
409 }
410 
journal_guess_blocks(journal_t * journal,blk64_t data_blocks,blk64_t revoke_blocks)411 static blk64_t journal_guess_blocks(journal_t *journal, blk64_t data_blocks,
412 				    blk64_t revoke_blocks)
413 {
414 	blk64_t ret = 1;
415 	unsigned int bs, sz;
416 
417 	/* Estimate # of revoke blocks */
418 	bs = journal->j_blocksize;
419 	if (journal_has_csum_v2or3(journal))
420 		bs -= sizeof(struct journal_revoke_tail);
421 	sz = jfs_has_feature_64bit(journal) ? sizeof(__u64) : sizeof(__u32);
422 	ret += revoke_blocks * sz / bs;
423 
424 	/* Estimate # of data blocks */
425 	bs = journal->j_blocksize - 16;
426 	if (journal_has_csum_v2or3(journal))
427 		bs -= sizeof(struct journal_block_tail);
428 	sz = journal_tag_bytes(journal);
429 	ret += data_blocks * sz / bs;
430 
431 	ret += data_blocks;
432 
433 	return ret;
434 }
435 
journal_open_trans(journal_t * journal,journal_transaction_t * trans,blk64_t blocks)436 static errcode_t journal_open_trans(journal_t *journal,
437 				    journal_transaction_t *trans,
438 				    blk64_t blocks)
439 {
440 	trans->fs = journal->j_fs_dev->k_fs;
441 	trans->journal = journal;
442 	trans->flags = J_TRANS_OPEN;
443 
444 	if (journal->j_tail == 0) {
445 		/* Clean journal, start at the tail */
446 		trans->tid = journal->j_tail_sequence;
447 		trans->start = journal->j_first;
448 	} else {
449 		/* Put new transaction at the head of the list */
450 		trans->tid = journal->j_transaction_sequence;
451 		trans->start = journal->j_head;
452 	}
453 
454 	trans->block = trans->start;
455 	if (trans->start + blocks > journal->j_last)
456 		return ENOSPC;
457 	trans->end = trans->block + blocks;
458 	journal_dump_trans(trans, "new transaction");
459 
460 	trans->magic = J_TRANS_MAGIC;
461 	return 0;
462 }
463 
journal_close_trans(journal_transaction_t * trans)464 static errcode_t journal_close_trans(journal_transaction_t *trans)
465 {
466 	journal_t *journal;
467 
468 	JOURNAL_CHECK_TRANS_MAGIC(trans);
469 
470 	if (!(trans->flags & J_TRANS_COMMITTED))
471 		return 0;
472 
473 	journal = trans->journal;
474 	if (journal->j_tail == 0) {
475 		/* Update the tail */
476 		journal->j_tail_sequence = trans->tid;
477 		journal->j_tail = trans->start;
478 		journal->j_superblock->s_start = ext2fs_cpu_to_be32(trans->start);
479 	}
480 
481 	/* Update the head */
482 	journal->j_head = trans->end + 1;
483 	journal->j_transaction_sequence = trans->tid + 1;
484 
485 	trans->magic = 0;
486 
487 	/* Mark ourselves as needing recovery */
488 	if (!ext2fs_has_feature_journal_needs_recovery(trans->fs->super)) {
489 		ext2fs_set_feature_journal_needs_recovery(trans->fs->super);
490 		ext2fs_mark_super_dirty(trans->fs);
491 	}
492 
493 	return 0;
494 }
495 
496 #define JOURNAL_WRITE_NO_COMMIT		1
journal_write(journal_t * journal,int flags,blk64_t * block_list,size_t block_len,blk64_t * revoke_list,size_t revoke_len,FILE * fp)497 static errcode_t journal_write(journal_t *journal,
498 			       int flags, blk64_t *block_list,
499 			       size_t block_len, blk64_t *revoke_list,
500 			       size_t revoke_len, FILE *fp)
501 {
502 	blk64_t blocks;
503 	journal_transaction_t trans;
504 	errcode_t err;
505 
506 	if (revoke_len > 0) {
507 		jfs_set_feature_revoke(journal);
508 		mark_buffer_dirty(journal->j_sb_buffer);
509 	}
510 
511 	blocks = journal_guess_blocks(journal, block_len, revoke_len);
512 	err = journal_open_trans(journal, &trans, blocks);
513 	if (err)
514 		goto error;
515 
516 	err = journal_add_blocks_to_trans(&trans, block_list, block_len, fp);
517 	if (err)
518 		goto error;
519 
520 	err = journal_add_revoke_to_trans(&trans, revoke_list, revoke_len);
521 	if (err)
522 		goto error;
523 
524 	if (!(flags & JOURNAL_WRITE_NO_COMMIT)) {
525 		err = journal_commit_trans(&trans);
526 		if (err)
527 			goto error;
528 	}
529 
530 	err = journal_close_trans(&trans);
531 	if (err)
532 		goto error;
533 error:
534 	return err;
535 }
536 
do_journal_write(int argc,char * argv[])537 void do_journal_write(int argc, char *argv[])
538 {
539 	blk64_t *blist = NULL, *rlist = NULL;
540 	size_t bn = 0, rn = 0;
541 	FILE *fp = NULL;
542 	int opt;
543 	int flags = 0;
544 	errcode_t err;
545 
546 	if (current_journal == NULL) {
547 		printf("Journal not open.\n");
548 		return;
549 	}
550 
551 	reset_getopt();
552 	while ((opt = getopt(argc, argv, "b:r:c")) != -1) {
553 		switch (opt) {
554 		case 'b':
555 			err = read_list(optarg, &blist, &bn);
556 			if (err)
557 				com_err(argv[0], err,
558 					"while reading block list");
559 			break;
560 		case 'r':
561 			err = read_list(optarg, &rlist, &rn);
562 			if (err)
563 				com_err(argv[0], err,
564 					"while reading revoke list");
565 			break;
566 		case 'c':
567 			flags |= JOURNAL_WRITE_NO_COMMIT;
568 			break;
569 		default:
570 			printf("%s [-b blocks] [-r revoke] [-c] file\n",
571 			       argv[0]);
572 			printf("-b: Write these blocks into transaction.\n");
573 			printf("-c: Do not commit transaction.\n");
574 			printf("-r: Revoke these blocks from transaction.\n");
575 
576 			goto out;
577 		}
578 	}
579 
580 	if (bn > 0 && optind != argc - 1) {
581 		printf("Need a file to read blocks from.\n");
582 		return;
583 	}
584 
585 	if (bn > 0) {
586 		fp = fopen(argv[optind], "r");
587 		if (fp == NULL) {
588 			com_err(argv[0], errno,
589 				"while opening journal data file");
590 			goto out;
591 		}
592 	}
593 
594 	err = journal_write(current_journal, flags, blist, bn,
595 			    rlist, rn, fp);
596 	if (err)
597 		com_err("journal_write", err, "while writing journal");
598 
599 	if (fp)
600 		fclose(fp);
601 out:
602 	if (blist)
603 		free(blist);
604 	if (rlist)
605 		free(rlist);
606 }
607 
608 /* Make sure we wrap around the log correctly! */
609 #define wrap(journal, var)						\
610 do {									\
611 	if (var >= (journal)->j_last)					\
612 		var -= ((journal)->j_last - (journal)->j_first);	\
613 } while (0)
614 
615 /*
616  * Count the number of in-use tags in a journal descriptor block.
617  */
618 
count_tags(journal_t * journal,char * buf)619 static int count_tags(journal_t *journal, char *buf)
620 {
621 	char			*tagp;
622 	journal_block_tag_t	*tag;
623 	int			nr = 0, size = journal->j_blocksize;
624 	int			tag_bytes = journal_tag_bytes(journal);
625 
626 	if (journal_has_csum_v2or3(journal))
627 		size -= sizeof(struct journal_block_tail);
628 
629 	tagp = buf + sizeof(journal_header_t);
630 
631 	while ((tagp - buf + tag_bytes) <= size) {
632 		tag = (journal_block_tag_t *) tagp;
633 
634 		nr++;
635 		tagp += tag_bytes;
636 		if (!(tag->t_flags & ext2fs_cpu_to_be16(JFS_FLAG_SAME_UUID)))
637 			tagp += 16;
638 
639 		if (tag->t_flags & ext2fs_cpu_to_be16(JFS_FLAG_LAST_TAG))
640 			break;
641 	}
642 
643 	return nr;
644 }
645 
journal_find_head(journal_t * journal)646 static errcode_t journal_find_head(journal_t *journal)
647 {
648 	unsigned int		next_commit_ID;
649 	blk64_t			next_log_block, head_block;
650 	int			err;
651 	journal_superblock_t	*sb;
652 	journal_header_t	*tmp;
653 	struct buffer_head	*bh;
654 	unsigned int		sequence;
655 	int			blocktype;
656 
657 	/*
658 	 * First thing is to establish what we expect to find in the log
659 	 * (in terms of transaction IDs), and where (in terms of log
660 	 * block offsets): query the superblock.
661 	 */
662 
663 	sb = journal->j_superblock;
664 	next_commit_ID = ext2fs_be32_to_cpu(sb->s_sequence);
665 	next_log_block = ext2fs_be32_to_cpu(sb->s_start);
666 	head_block = next_log_block;
667 
668 	if (next_log_block == 0)
669 		return 0;
670 
671 	bh = getblk(journal->j_dev, 0, journal->j_blocksize);
672 	if (bh == NULL)
673 		return ENOMEM;
674 
675 	/*
676 	 * Now we walk through the log, transaction by transaction,
677 	 * making sure that each transaction has a commit block in the
678 	 * expected place.  Each complete transaction gets replayed back
679 	 * into the main filesystem.
680 	 */
681 	while (1) {
682 		dbg_printf("Scanning for sequence ID %u at %lu/%lu\n",
683 			  next_commit_ID, (unsigned long)next_log_block,
684 			  journal->j_last);
685 
686 		/* Skip over each chunk of the transaction looking
687 		 * either the next descriptor block or the final commit
688 		 * record. */
689 		err = journal_bmap(journal, next_log_block, &bh->b_blocknr);
690 		if (err)
691 			goto err;
692 		mark_buffer_uptodate(bh, 0);
693 		ll_rw_block(READ, 1, &bh);
694 		err = bh->b_err;
695 		if (err)
696 			goto err;
697 
698 		next_log_block++;
699 		wrap(journal, next_log_block);
700 
701 		/* What kind of buffer is it?
702 		 *
703 		 * If it is a descriptor block, check that it has the
704 		 * expected sequence number.  Otherwise, we're all done
705 		 * here. */
706 
707 		tmp = (journal_header_t *)bh->b_data;
708 
709 		if (tmp->h_magic != ext2fs_cpu_to_be32(JFS_MAGIC_NUMBER)) {
710 			dbg_printf("JBD2: wrong magic 0x%x\n", tmp->h_magic);
711 			goto err;
712 		}
713 
714 		blocktype = ext2fs_be32_to_cpu(tmp->h_blocktype);
715 		sequence = ext2fs_be32_to_cpu(tmp->h_sequence);
716 		dbg_printf("Found magic %d, sequence %d\n",
717 			  blocktype, sequence);
718 
719 		if (sequence != next_commit_ID) {
720 			dbg_printf("JBD2: Wrong sequence %d (wanted %d)\n",
721 				   sequence, next_commit_ID);
722 			goto err;
723 		}
724 
725 		/* OK, we have a valid descriptor block which matches
726 		 * all of the sequence number checks.  What are we going
727 		 * to do with it?  That depends on the pass... */
728 
729 		switch (blocktype) {
730 		case JFS_DESCRIPTOR_BLOCK:
731 			next_log_block += count_tags(journal, bh->b_data);
732 			wrap(journal, next_log_block);
733 			continue;
734 
735 		case JFS_COMMIT_BLOCK:
736 			head_block = next_log_block;
737 			next_commit_ID++;
738 			continue;
739 
740 		case JFS_REVOKE_BLOCK:
741 			continue;
742 
743 		default:
744 			dbg_printf("Unrecognised magic %d, end of scan.\n",
745 				  blocktype);
746 			err = -EINVAL;
747 			goto err;
748 		}
749 	}
750 
751 err:
752 	if (err == 0) {
753 		dbg_printf("head seq=%d blk=%llu\n", next_commit_ID,
754 			   head_block);
755 		journal->j_transaction_sequence = next_commit_ID;
756 		journal->j_head = head_block;
757 	}
758 	brelse(bh);
759 	return err;
760 }
761 
update_journal_csum(journal_t * journal,int ver)762 static void update_journal_csum(journal_t *journal, int ver)
763 {
764 	journal_superblock_t *jsb;
765 
766 	if (journal->j_format_version < 2)
767 		return;
768 
769 	if (journal->j_tail != 0 ||
770 	    ext2fs_has_feature_journal_needs_recovery(
771 					journal->j_fs_dev->k_fs->super)) {
772 		printf("Journal needs recovery, will not add csums.\n");
773 		return;
774 	}
775 
776 	/* metadata_csum implies journal csum v3 */
777 	jsb = journal->j_superblock;
778 	if (ext2fs_has_feature_metadata_csum(journal->j_fs_dev->k_fs->super)) {
779 		printf("Setting csum v%d\n", ver);
780 		switch (ver) {
781 		case 2:
782 			jfs_clear_feature_csum3(journal);
783 			jfs_set_feature_csum2(journal);
784 			jfs_clear_feature_checksum(journal);
785 			break;
786 		case 3:
787 			jfs_set_feature_csum3(journal);
788 			jfs_clear_feature_csum2(journal);
789 			jfs_clear_feature_checksum(journal);
790 			break;
791 		default:
792 			printf("Unknown checksum v%d\n", ver);
793 			break;
794 		}
795 		journal->j_superblock->s_checksum_type = JBD2_CRC32C_CHKSUM;
796 		journal->j_csum_seed = jbd2_chksum(journal, ~0, jsb->s_uuid,
797 						   sizeof(jsb->s_uuid));
798 	} else {
799 		jfs_clear_feature_csum3(journal);
800 		jfs_clear_feature_csum2(journal);
801 		jfs_set_feature_checksum(journal);
802 	}
803 }
804 
update_uuid(journal_t * journal)805 static void update_uuid(journal_t *journal)
806 {
807 	size_t z;
808 	ext2_filsys fs;
809 
810 	if (journal->j_format_version < 2)
811 		return;
812 
813 	for (z = 0; z < sizeof(journal->j_superblock->s_uuid); z++)
814 		if (journal->j_superblock->s_uuid[z])
815 			break;
816 	if (z == 0)
817 		return;
818 
819 	fs = journal->j_fs_dev->k_fs;
820 	if (!ext2fs_has_feature_64bit(fs->super))
821 		return;
822 
823 	if (jfs_has_feature_64bit(journal) &&
824 	    ext2fs_has_feature_64bit(fs->super))
825 		return;
826 
827 	if (journal->j_tail != 0 ||
828 	    ext2fs_has_feature_journal_needs_recovery(fs->super)) {
829 		printf("Journal needs recovery, will not set 64bit.\n");
830 		return;
831 	}
832 
833 	memcpy(journal->j_superblock->s_uuid, fs->super->s_uuid,
834 	       sizeof(fs->super->s_uuid));
835 }
836 
update_64bit_flag(journal_t * journal)837 static void update_64bit_flag(journal_t *journal)
838 {
839 	if (journal->j_format_version < 2)
840 		return;
841 
842 	if (!ext2fs_has_feature_64bit(journal->j_fs_dev->k_fs->super))
843 		return;
844 
845 	if (jfs_has_feature_64bit(journal) &&
846 	    ext2fs_has_feature_64bit(journal->j_fs_dev->k_fs->super))
847 		return;
848 
849 	if (journal->j_tail != 0 ||
850 	    ext2fs_has_feature_journal_needs_recovery(
851 				journal->j_fs_dev->k_fs->super)) {
852 		printf("Journal needs recovery, will not set 64bit.\n");
853 		return;
854 	}
855 
856 	jfs_set_feature_64bit(journal);
857 }
858 
do_journal_open(int argc,char * argv[])859 void do_journal_open(int argc, char *argv[])
860 {
861 	int opt, enable_csum = 0, csum_ver = 3;
862 	journal_t *journal;
863 	errcode_t err;
864 
865 	if (check_fs_open(argv[0]))
866 		return;
867 	if (check_fs_read_write(argv[0]))
868 		return;
869 	if (check_fs_bitmaps(argv[0]))
870 		return;
871 	if (current_journal) {
872 		printf("Journal is already open.\n");
873 		return;
874 	}
875 	if (!ext2fs_has_feature_journal(current_fs->super)) {
876 		printf("Journalling is not enabled on this filesystem.\n");
877 		return;
878 	}
879 
880 	reset_getopt();
881 	while ((opt = getopt(argc, argv, "cv:f:")) != -1) {
882 		switch (opt) {
883 		case 'c':
884 			enable_csum = 1;
885 			break;
886 		case 'f':
887 			if (current_fs->journal_name)
888 				free(current_fs->journal_name);
889 			current_fs->journal_name = strdup(optarg);
890 			break;
891 		case 'v':
892 			csum_ver = atoi(optarg);
893 			if (csum_ver != 2 && csum_ver != 3) {
894 				printf("Unknown journal csum v%d\n", csum_ver);
895 				csum_ver = 3;
896 			}
897 			break;
898 		default:
899 			printf("%s: [-c] [-v ver] [-f ext_jnl]\n", argv[0]);
900 			printf("-c: Enable journal checksumming.\n");
901 			printf("-v: Use this version checksum format.\n");
902 			printf("-j: Load this external journal.\n");
903 		}
904 	}
905 
906 	err = ext2fs_open_journal(current_fs, &current_journal);
907 	if (err) {
908 		com_err(argv[0], err, "while opening journal");
909 		return;
910 	}
911 	journal = current_journal;
912 
913 	dbg_printf("JOURNAL: seq=%d tailseq=%d start=%lu first=%lu "
914 		   "maxlen=%lu\n", journal->j_tail_sequence,
915 		   journal->j_transaction_sequence, journal->j_tail,
916 		   journal->j_first, journal->j_last);
917 
918 	update_uuid(journal);
919 	update_64bit_flag(journal);
920 	if (enable_csum)
921 		update_journal_csum(journal, csum_ver);
922 
923 	err = journal_find_head(journal);
924 	if (err)
925 		com_err(argv[0], err, "while examining journal");
926 }
927 
do_journal_close(int argc EXT2FS_ATTR ((unused)),char * argv[]EXT2FS_ATTR ((unused)))928 void do_journal_close(int argc EXT2FS_ATTR((unused)),
929 		      char *argv[] EXT2FS_ATTR((unused)))
930 {
931 	if (current_journal == NULL) {
932 		printf("Journal not open.\n");
933 		return;
934 	}
935 
936 	ext2fs_close_journal(current_fs, &current_journal);
937 }
938 
do_journal_run(int argc EXT2FS_ATTR ((unused)),char * argv[])939 void do_journal_run(int argc EXT2FS_ATTR((unused)), char *argv[])
940 {
941 	errcode_t err;
942 
943 	if (check_fs_open(argv[0]))
944 		return;
945 	if (check_fs_read_write(argv[0]))
946 		return;
947 	if (check_fs_bitmaps(argv[0]))
948 		return;
949 	if (current_journal) {
950 		printf("Please close the journal before recovering it.\n");
951 		return;
952 	}
953 
954 	err = ext2fs_run_ext3_journal(&current_fs);
955 	if (err)
956 		com_err("journal_run", err, "while recovering journal");
957 	else {
958 		ext2fs_clear_feature_journal_needs_recovery(current_fs->super);
959 		ext2fs_mark_super_dirty(current_fs);
960 	}
961 }
962