1 /*
2  * journal.c --- code for handling the "ext3" journal
3  *
4  * Copyright (C) 2000 Andreas Dilger
5  * Copyright (C) 2000 Theodore Ts'o
6  *
7  * Parts of the code are based on fs/jfs/journal.c by Stephen C. Tweedie
8  * Copyright (C) 1999 Red Hat Software
9  *
10  * This file may be redistributed under the terms of the
11  * GNU General Public License version 2 or at your discretion
12  * any later version.
13  */
14 
15 #include "config.h"
16 #ifdef HAVE_SYS_MOUNT_H
17 #include <sys/param.h>
18 #include <sys/mount.h>
19 #define MNT_FL (MS_MGC_VAL | MS_RDONLY)
20 #endif
21 #ifdef HAVE_SYS_STAT_H
22 #include <sys/stat.h>
23 #endif
24 
25 #define E2FSCK_INCLUDE_INLINE_FUNCS
26 #include "uuid/uuid.h"
27 #include "journal.h"
28 
29 static int bh_count = 0;
30 
31 #if EXT2_FLAT_INCLUDES
htree_dump_leaf_node(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode,struct ext2_dx_root_info * rootnode,blk64_t blk,char * buf)32 #include "blkid.h"
33 #else
34 #include "blkid/blkid.h"
35 #endif
36 
37 /*
38  * Define USE_INODE_IO to use the inode_io.c / fileio.c codepaths.
39  * This creates a larger static binary, and a smaller binary using
40  * shared libraries.  It's also probably slightly less CPU-efficient,
41  * which is why it's not on by default.  But, it's a good way of
42  * testing the functions in inode_io.c and fileio.c.
43  */
44 #undef USE_INODE_IO
45 
46 /* Checksumming functions */
47 static int ext2fs_journal_verify_csum_type(journal_t *j,
48 					   journal_superblock_t *jsb)
49 {
50 	if (!jbd2_journal_has_csum_v2or3(j))
51 		return 1;
52 
53 	return jsb->s_checksum_type == JBD2_CRC32C_CHKSUM;
54 }
55 
56 static __u32 ext2fs_journal_sb_csum(journal_superblock_t *jsb)
57 {
58 	__u32 crc, old_crc;
59 
60 	old_crc = jsb->s_checksum;
61 	jsb->s_checksum = 0;
62 	crc = ext2fs_crc32c_le(~0, (unsigned char *)jsb,
63 			       sizeof(journal_superblock_t));
64 	jsb->s_checksum = old_crc;
65 
66 	return crc;
67 }
68 
69 static int ext2fs_journal_sb_csum_verify(journal_t *j,
70 					 journal_superblock_t *jsb)
71 {
72 	__u32 provided, calculated;
73 
74 	if (!jbd2_journal_has_csum_v2or3(j))
75 		return 1;
76 
77 	provided = ext2fs_be32_to_cpu(jsb->s_checksum);
78 	calculated = ext2fs_journal_sb_csum(jsb);
79 
80 	return provided == calculated;
81 }
82 
83 static errcode_t ext2fs_journal_sb_csum_set(journal_t *j,
84 					    journal_superblock_t *jsb)
85 {
86 	__u32 crc;
87 
88 	if (!jbd2_journal_has_csum_v2or3(j))
89 		return 0;
90 
91 	crc = ext2fs_journal_sb_csum(jsb);
92 	jsb->s_checksum = ext2fs_cpu_to_be32(crc);
93 	return 0;
94 }
95 
96 /* Kernel compatibility functions for handling the journal.  These allow us
97  * to use the recovery.c file virtually unchanged from the kernel, so we
98  * don't have to do much to keep kernel and user recovery in sync.
99  */
100 int jbd2_journal_bmap(journal_t *journal, unsigned long block,
101 		      unsigned long long *phys)
102 {
103 #ifdef USE_INODE_IO
104 	*phys = block;
105 	return 0;
106 #else
107 	struct inode	*inode = journal->j_inode;
108 	errcode_t	retval;
109 	blk64_t		pblk;
110 
111 	if (!inode) {
112 		*phys = block;
113 		return 0;
114 	}
115 
116 	retval = ext2fs_bmap2(inode->i_fs, inode->i_ino,
117 			      &inode->i_ext2, NULL, 0, (blk64_t) block,
118 			      0, &pblk);
119 	*phys = pblk;
120 	return (int) retval;
121 #endif
122 }
123 
124 struct buffer_head *getblk(kdev_t kdev, unsigned long long blocknr,
125 			   int blocksize)
126 {
127 	struct buffer_head *bh;
128 	int bufsize = sizeof(*bh) + kdev->k_fs->blocksize -
129 		sizeof(bh->b_data);
130 	errcode_t retval;
131 
132 	retval = ext2fs_get_memzero(bufsize, &bh);
133 	if (retval)
134 		return NULL;
135 
136 	if (journal_enable_debug >= 3)
137 		bh_count++;
htree_dump_int_node(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode,struct ext2_dx_root_info * rootnode,struct ext2_dx_entry * ent,__u32 crc,char * buf,int level)138 	jfs_debug(4, "getblk for block %llu (%d bytes)(total %d)\n",
139 		  blocknr, blocksize, bh_count);
140 
141 	bh->b_fs = kdev->k_fs;
142 	if (kdev->k_dev == K_DEV_FS)
143 		bh->b_io = kdev->k_fs->io;
144 	else
145 		bh->b_io = kdev->k_fs->journal_io;
146 	bh->b_size = blocksize;
147 	bh->b_blocknr = blocknr;
148 
149 	return bh;
150 }
151 
152 int sync_blockdev(kdev_t kdev)
153 {
154 	io_channel	io;
155 
156 	if (kdev->k_dev == K_DEV_FS)
157 		io = kdev->k_fs->io;
158 	else
159 		io = kdev->k_fs->journal_io;
160 
161 	return io_channel_flush(io) ? EIO : 0;
162 }
163 
164 void ll_rw_block(int rw, int op_flags EXT2FS_ATTR((unused)), int nr,
165 		 struct buffer_head *bhp[])
166 {
167 	errcode_t retval;
168 	struct buffer_head *bh;
169 
170 	for (; nr > 0; --nr) {
171 		bh = *bhp++;
172 		if (rw == REQ_OP_READ && !bh->b_uptodate) {
173 			jfs_debug(3, "reading block %llu/%p\n",
174 				  bh->b_blocknr, (void *) bh);
175 			retval = io_channel_read_blk64(bh->b_io,
176 						     bh->b_blocknr,
177 						     1, bh->b_data);
178 			if (retval) {
179 				com_err(bh->b_fs->device_name, retval,
180 					"while reading block %llu\n",
181 					bh->b_blocknr);
182 				bh->b_err = (int) retval;
183 				continue;
184 			}
185 			bh->b_uptodate = 1;
186 		} else if (rw == REQ_OP_WRITE && bh->b_dirty) {
187 			jfs_debug(3, "writing block %llu/%p\n",
188 				  bh->b_blocknr,
189 				  (void *) bh);
190 			retval = io_channel_write_blk64(bh->b_io,
191 						      bh->b_blocknr,
192 						      1, bh->b_data);
193 			if (retval) {
194 				com_err(bh->b_fs->device_name, retval,
195 					"while writing block %llu\n",
196 					bh->b_blocknr);
197 				bh->b_err = (int) retval;
198 				continue;
htree_dump_int_block(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode,struct ext2_dx_root_info * rootnode,blk64_t blk,char * buf,int level)199 			}
200 			bh->b_dirty = 0;
201 			bh->b_uptodate = 1;
202 		} else {
203 			jfs_debug(3, "no-op %s for block %llu\n",
204 				  rw == REQ_OP_READ ? "read" : "write",
205 				  bh->b_blocknr);
206 		}
207 	}
208 }
209 
210 void mark_buffer_dirty(struct buffer_head *bh)
211 {
212 	bh->b_dirty = 1;
213 }
214 
215 static void mark_buffer_clean(struct buffer_head *bh)
216 {
217 	bh->b_dirty = 0;
218 }
219 
220 void brelse(struct buffer_head *bh)
221 {
222 	if (bh->b_dirty)
223 		ll_rw_block(REQ_OP_WRITE, 0, 1, &bh);
224 	jfs_debug(3, "freeing block %llu/%p (total %d)\n",
225 		  bh->b_blocknr, (void *) bh, --bh_count);
226 	ext2fs_free_mem(&bh);
227 }
228 
229 int buffer_uptodate(struct buffer_head *bh)
230 {
231 	return bh->b_uptodate;
232 }
233 
234 void mark_buffer_uptodate(struct buffer_head *bh, int val)
235 {
236 	bh->b_uptodate = val;
237 }
238 
239 void wait_on_buffer(struct buffer_head *bh)
240 {
241 	if (!bh->b_uptodate)
242 		ll_rw_block(REQ_OP_READ, 0, 1, &bh);
243 }
244 
245 
246 static void ext2fs_clear_recover(ext2_filsys fs, int error)
247 {
do_htree_dump(int argc,char * argv[],int sci_idx EXT2FS_ATTR ((unused)),void * infop EXT2FS_ATTR ((unused)))248 	ext2fs_clear_feature_journal_needs_recovery(fs->super);
249 
250 	/* if we had an error doing journal recovery, we need a full fsck */
251 	if (error)
252 		fs->super->s_state &= ~EXT2_VALID_FS;
253 	/*
254 	 * If we replayed the journal by definition the file system
255 	 * was mounted since the last time it was checked
256 	 */
257 	if (fs->super->s_lastcheck >= fs->super->s_mtime)
258 		fs->super->s_lastcheck = fs->super->s_mtime - 1;
259 	ext2fs_mark_super_dirty(fs);
260 }
261 
262 /*
263  * This is a helper function to check the validity of the journal.
264  */
265 struct process_block_struct {
266 	e2_blkcnt_t	last_block;
267 };
268 
269 static int process_journal_block(ext2_filsys fs,
270 				 blk64_t	*block_nr,
271 				 e2_blkcnt_t blockcnt,
272 				 blk64_t ref_block EXT2FS_ATTR((unused)),
273 				 int ref_offset EXT2FS_ATTR((unused)),
274 				 void *priv_data)
275 {
276 	struct process_block_struct *p;
277 	blk64_t	blk = *block_nr;
278 
279 	p = (struct process_block_struct *) priv_data;
280 
281 	if (!blk || blk < fs->super->s_first_data_block ||
282 	    blk >= ext2fs_blocks_count(fs->super))
283 		return BLOCK_ABORT;
284 
285 	if (blockcnt >= 0)
286 		p->last_block = blockcnt;
287 	return 0;
288 }
289 
290 static errcode_t ext2fs_get_journal(ext2_filsys fs, journal_t **ret_journal)
291 {
292 	struct process_block_struct pb;
293 	struct ext2_super_block *sb = fs->super;
294 	struct ext2_super_block jsuper;
295 	struct buffer_head	*bh;
296 	struct inode		*j_inode = NULL;
297 	struct kdev_s		*dev_fs = NULL, *dev_journal;
298 	const char		*journal_name = 0;
299 	journal_t		*journal = NULL;
300 	errcode_t		retval = 0;
301 	io_manager		io_ptr = 0;
302 	unsigned long long	start = 0;
303 	int			ext_journal = 0;
304 	int			tried_backup_jnl = 0;
305 
306 	retval = ext2fs_get_memzero(sizeof(journal_t), &journal);
307 	if (retval)
308 		return retval;
309 
310 	retval = ext2fs_get_memzero(2 * sizeof(struct kdev_s), &dev_fs);
311 	if (retval)
312 		goto errout;
313 	dev_journal = dev_fs+1;
314 
315 	dev_fs->k_fs = dev_journal->k_fs = fs;
316 	dev_fs->k_dev = K_DEV_FS;
317 	dev_journal->k_dev = K_DEV_JOURNAL;
318 
319 	journal->j_dev = dev_journal;
320 	journal->j_fs_dev = dev_fs;
321 	journal->j_inode = NULL;
322 	journal->j_blocksize = fs->blocksize;
323 
324 	if (uuid_is_null(sb->s_journal_uuid)) {
325 		if (!sb->s_journal_inum) {
326 			retval = EXT2_ET_BAD_INODE_NUM;
327 			goto errout;
328 		}
329 		retval = ext2fs_get_memzero(sizeof(*j_inode), &j_inode);
330 		if (retval)
331 			goto errout;
do_dx_hash(int argc,char * argv[],int sci_idx EXT2FS_ATTR ((unused)),void * infop EXT2FS_ATTR ((unused)))332 
333 		j_inode->i_fs = fs;
334 		j_inode->i_ino = sb->s_journal_inum;
335 
336 		retval = ext2fs_read_inode(fs, sb->s_journal_inum,
337 					   &j_inode->i_ext2);
338 		if (retval) {
339 try_backup_journal:
340 			if (sb->s_jnl_backup_type != EXT3_JNL_BACKUP_BLOCKS ||
341 			    tried_backup_jnl)
342 				goto errout;
343 			memset(&j_inode->i_ext2, 0, sizeof(struct ext2_inode));
344 			memcpy(&j_inode->i_ext2.i_block[0], sb->s_jnl_blocks,
345 			       EXT2_N_BLOCKS*4);
346 			j_inode->i_ext2.i_size_high = sb->s_jnl_blocks[15];
347 			j_inode->i_ext2.i_size = sb->s_jnl_blocks[16];
348 			j_inode->i_ext2.i_links_count = 1;
349 			j_inode->i_ext2.i_mode = LINUX_S_IFREG | 0600;
350 			tried_backup_jnl++;
351 		}
352 		if (!j_inode->i_ext2.i_links_count ||
353 		    !LINUX_S_ISREG(j_inode->i_ext2.i_mode)) {
354 			retval = EXT2_ET_NO_JOURNAL;
355 			goto try_backup_journal;
356 		}
357 		if (EXT2_I_SIZE(&j_inode->i_ext2) / journal->j_blocksize <
358 		    JBD2_MIN_JOURNAL_BLOCKS) {
359 			retval = EXT2_ET_JOURNAL_TOO_SMALL;
360 			goto try_backup_journal;
361 		}
362 		pb.last_block = -1;
363 		retval = ext2fs_block_iterate3(fs, j_inode->i_ino,
364 					       BLOCK_FLAG_HOLE, 0,
365 					       process_journal_block, &pb);
366 		if ((pb.last_block + 1) * fs->blocksize <
367 		    (int) EXT2_I_SIZE(&j_inode->i_ext2)) {
368 			retval = EXT2_ET_JOURNAL_TOO_SMALL;
369 			goto try_backup_journal;
370 		}
371 		if (tried_backup_jnl && (fs->flags & EXT2_FLAG_RW)) {
372 			retval = ext2fs_write_inode(fs, sb->s_journal_inum,
373 						    &j_inode->i_ext2);
374 			if (retval)
375 				goto errout;
376 		}
377 
378 		journal->j_total_len = EXT2_I_SIZE(&j_inode->i_ext2) /
379 			journal->j_blocksize;
380 
381 #ifdef USE_INODE_IO
382 		retval = ext2fs_inode_io_intern2(fs, sb->s_journal_inum,
383 						 &j_inode->i_ext2,
384 						 &journal_name);
385 		if (retval)
386 			goto errout;
387 
388 		io_ptr = inode_io_manager;
389 #else
390 		journal->j_inode = j_inode;
391 		fs->journal_io = fs->io;
392 		retval = (errcode_t) jbd2_journal_bmap(journal, 0, &start);
393 		if (retval)
394 			goto errout;
395 #endif
396 	} else {
397 		ext_journal = 1;
398 		if (!fs->journal_name) {
399 			char uuid[37];
400 			blkid_cache blkid;
401 
402 			blkid_get_cache(&blkid, NULL);
403 			uuid_unparse(sb->s_journal_uuid, uuid);
404 			fs->journal_name = blkid_get_devname(blkid,
405 							      "UUID", uuid);
406 			if (!fs->journal_name)
407 				fs->journal_name = blkid_devno_to_devname(sb->s_journal_dev);
do_dirsearch(int argc,char * argv[],int sci_idx EXT2FS_ATTR ((unused)),void * infop EXT2FS_ATTR ((unused)))408 			blkid_put_cache(blkid);
409 		}
410 		journal_name = fs->journal_name;
411 
412 		if (!journal_name) {
413 			retval = EXT2_ET_LOAD_EXT_JOURNAL;
414 			goto errout;
415 		}
416 
417 		jfs_debug(1, "Using journal file %s\n", journal_name);
418 		io_ptr = unix_io_manager;
419 	}
420 
421 #if 0
422 	test_io_backing_manager = io_ptr;
423 	io_ptr = test_io_manager;
424 #endif
425 #ifndef USE_INODE_IO
426 	if (ext_journal)
427 #endif
428 	{
429 		retval = io_ptr->open(journal_name, fs->flags & EXT2_FLAG_RW,
430 				      &fs->journal_io);
431 	}
432 	if (retval)
433 		goto errout;
434 
435 	io_channel_set_blksize(fs->journal_io, fs->blocksize);
436 
437 	if (ext_journal) {
438 		blk64_t maxlen;
439 
440 		start = ext2fs_journal_sb_start(fs->blocksize) - 1;
search_dir_block(ext2_filsys fs,blk64_t * blocknr,e2_blkcnt_t blockcnt,blk64_t ref_blk EXT2FS_ATTR ((unused)),int ref_offset EXT2FS_ATTR ((unused)),void * priv_data)441 		bh = getblk(dev_journal, start, fs->blocksize);
442 		if (!bh) {
443 			retval = EXT2_ET_NO_MEMORY;
444 			goto errout;
445 		}
446 		ll_rw_block(REQ_OP_READ, 0, 1, &bh);
447 		retval = bh->b_err;
448 		if (retval) {
449 			brelse(bh);
450 			goto errout;
451 		}
452 		memcpy(&jsuper, start ? bh->b_data :
453 				bh->b_data + SUPERBLOCK_OFFSET,
454 		       sizeof(jsuper));
455 #ifdef WORDS_BIGENDIAN
456 		if (jsuper.s_magic == ext2fs_swab16(EXT2_SUPER_MAGIC))
457 			ext2fs_swap_super(&jsuper);
458 #endif
459 		if (jsuper.s_magic != EXT2_SUPER_MAGIC ||
460 		    !ext2fs_has_feature_journal_dev(&jsuper)) {
461 			retval = EXT2_ET_LOAD_EXT_JOURNAL;
462 			brelse(bh);
463 			goto errout;
464 		}
465 		/* Make sure the journal UUID is correct */
466 		if (memcmp(jsuper.s_uuid, fs->super->s_journal_uuid,
467 			   sizeof(jsuper.s_uuid))) {
468 			retval = EXT2_ET_LOAD_EXT_JOURNAL;
469 			brelse(bh);
470 			goto errout;
471 		}
472 
473 		/* Check the superblock checksum */
474 		if (ext2fs_has_feature_metadata_csum(&jsuper)) {
475 			struct struct_ext2_filsys fsx;
476 			struct ext2_super_block	superx;
477 			void *p;
478 
479 			p = start ? bh->b_data : bh->b_data + SUPERBLOCK_OFFSET;
480 			memcpy(&fsx, fs, sizeof(fsx));
481 			memcpy(&superx, fs->super, sizeof(superx));
482 			fsx.super = &superx;
483 			ext2fs_set_feature_metadata_csum(fsx.super);
484 			if (!ext2fs_superblock_csum_verify(&fsx, p)) {
485 				retval = EXT2_ET_LOAD_EXT_JOURNAL;
486 				brelse(bh);
487 				goto errout;
488 			}
489 		}
490 		brelse(bh);
491 
492 		maxlen = ext2fs_blocks_count(&jsuper);
493 		journal->j_total_len = (maxlen < 1ULL << 32) ? maxlen :
494 				    (1ULL << 32) - 1;
495 		start++;
496 	}
497 
498 	bh = getblk(dev_journal, start, journal->j_blocksize);
499 	if (!bh) {
500 		retval = EXT2_ET_NO_MEMORY;
501 		goto errout;
502 	}
503 
504 	journal->j_sb_buffer = bh;
505 	journal->j_superblock = (journal_superblock_t *)bh->b_data;
506 
507 #ifdef USE_INODE_IO
508 	if (j_inode)
509 		ext2fs_free_mem(&j_inode);
510 #endif
511 
512 	*ret_journal = journal;
513 	return 0;
514 
515 errout:
516 	if (dev_fs)
517 		ext2fs_free_mem(&dev_fs);
518 	if (j_inode)
519 		ext2fs_free_mem(&j_inode);
520 	if (journal)
521 		ext2fs_free_mem(&journal);
522 	return retval;
523 }
524 
525 static errcode_t ext2fs_journal_fix_bad_inode(ext2_filsys fs)
526 {
527 	struct ext2_super_block *sb = fs->super;
528 	int recover = ext2fs_has_feature_journal_needs_recovery(fs->super);
529 	int has_journal = ext2fs_has_feature_journal(fs->super);
530 
531 	if (has_journal || sb->s_journal_inum) {
532 		/* The journal inode is bogus, remove and force full fsck */
533 		return EXT2_ET_BAD_INODE_NUM;
534 	} else if (recover) {
535 		return EXT2_ET_UNSUPP_FEATURE;
536 	}
537 	return 0;
538 }
539 
540 #define V1_SB_SIZE	0x0024
541 static void clear_v2_journal_fields(journal_t *journal)
542 {
543 	ext2_filsys fs = journal->j_dev->k_fs;
544 
545 	memset(((char *) journal->j_superblock) + V1_SB_SIZE, 0,
546 	       fs->blocksize-V1_SB_SIZE);
547 	mark_buffer_dirty(journal->j_sb_buffer);
548 }
549 
550 
551 static errcode_t ext2fs_journal_load(journal_t *journal)
552 {
553 	ext2_filsys fs = journal->j_dev->k_fs;
554 	journal_superblock_t *jsb;
555 	struct buffer_head *jbh = journal->j_sb_buffer;
556 
557 	ll_rw_block(REQ_OP_READ, 0, 1, &jbh);
558 	if (jbh->b_err)
559 		return jbh->b_err;
560 
561 	jsb = journal->j_superblock;
562 	/* If we don't even have JBD2_MAGIC, we probably have a wrong inode */
563 	if (jsb->s_header.h_magic != htonl(JBD2_MAGIC_NUMBER))
564 		return ext2fs_journal_fix_bad_inode(fs);
565 
566 	switch (ntohl(jsb->s_header.h_blocktype)) {
567 	case JBD2_SUPERBLOCK_V1:
568 		journal->j_format_version = 1;
569 		if (jsb->s_feature_compat ||
570 		    jsb->s_feature_incompat ||
571 		    jsb->s_feature_ro_compat ||
572 		    jsb->s_nr_users)
573 			clear_v2_journal_fields(journal);
574 		break;
575 
576 	case JBD2_SUPERBLOCK_V2:
577 		journal->j_format_version = 2;
578 		if (ntohl(jsb->s_nr_users) > 1 &&
579 		    uuid_is_null(fs->super->s_journal_uuid))
580 			clear_v2_journal_fields(journal);
581 		if (ntohl(jsb->s_nr_users) > 1)
582 			return EXT2_ET_JOURNAL_UNSUPP_VERSION;
583 		break;
584 
585 	/*
586 	 * These should never appear in a journal super block, so if
587 	 * they do, the journal is badly corrupted.
588 	 */
589 	case JBD2_DESCRIPTOR_BLOCK:
590 	case JBD2_COMMIT_BLOCK:
591 	case JBD2_REVOKE_BLOCK:
592 		return EXT2_ET_CORRUPT_JOURNAL_SB;
593 
594 	/* If we don't understand the superblock major type, but there
595 	 * is a magic number, then it is likely to be a new format we
596 	 * just don't understand, so leave it alone. */
597 	default:
598 		return EXT2_ET_JOURNAL_UNSUPP_VERSION;
599 	}
600 
601 	if (JBD2_HAS_INCOMPAT_FEATURE(journal, ~JBD2_KNOWN_INCOMPAT_FEATURES))
602 		return EXT2_ET_UNSUPP_FEATURE;
603 
604 	if (JBD2_HAS_RO_COMPAT_FEATURE(journal, ~JBD2_KNOWN_ROCOMPAT_FEATURES))
605 		return EXT2_ET_RO_UNSUPP_FEATURE;
606 
607 	/* Checksum v1-3 are mutually exclusive features. */
608 	if (jbd2_has_feature_csum2(journal) && jbd2_has_feature_csum3(journal))
609 		return EXT2_ET_CORRUPT_JOURNAL_SB;
610 
611 	if (jbd2_journal_has_csum_v2or3(journal) &&
612 	    jbd2_has_feature_checksum(journal))
613 		return EXT2_ET_CORRUPT_JOURNAL_SB;
614 
615 	if (!ext2fs_journal_verify_csum_type(journal, jsb) ||
616 	    !ext2fs_journal_sb_csum_verify(journal, jsb))
617 		return EXT2_ET_CORRUPT_JOURNAL_SB;
618 
619 	if (jbd2_journal_has_csum_v2or3(journal))
620 		journal->j_csum_seed = jbd2_chksum(journal, ~0, jsb->s_uuid,
621 						   sizeof(jsb->s_uuid));
622 
623 	/* We have now checked whether we know enough about the journal
624 	 * format to be able to proceed safely, so any other checks that
625 	 * fail we should attempt to recover from. */
626 	if (jsb->s_blocksize != htonl(journal->j_blocksize))
627 		return EXT2_ET_CORRUPT_JOURNAL_SB;
628 
629 	if (ntohl(jsb->s_maxlen) < journal->j_total_len)
630 		journal->j_total_len = ntohl(jsb->s_maxlen);
631 	else if (ntohl(jsb->s_maxlen) > journal->j_total_len)
632 		return EXT2_ET_CORRUPT_JOURNAL_SB;
633 
634 	journal->j_tail_sequence = ntohl(jsb->s_sequence);
635 	journal->j_transaction_sequence = journal->j_tail_sequence;
636 	journal->j_tail = ntohl(jsb->s_start);
637 	journal->j_first = ntohl(jsb->s_first);
638 	journal->j_last = ntohl(jsb->s_maxlen);
639 
640 	return 0;
641 }
642 
643 static void ext2fs_journal_release(ext2_filsys fs, journal_t *journal,
644 				   int reset, int drop)
645 {
646 	journal_superblock_t *jsb;
647 
648 	if (drop)
649 		mark_buffer_clean(journal->j_sb_buffer);
650 	else if (fs->flags & EXT2_FLAG_RW) {
651 		jsb = journal->j_superblock;
652 		jsb->s_sequence = htonl(journal->j_tail_sequence);
653 		if (reset)
654 			jsb->s_start = 0; /* this marks the journal as empty */
655 		ext2fs_journal_sb_csum_set(journal, jsb);
656 		mark_buffer_dirty(journal->j_sb_buffer);
657 	}
658 	brelse(journal->j_sb_buffer);
659 
660 	if (fs && fs->journal_io) {
661 		if (fs->io != fs->journal_io)
662 			io_channel_close(fs->journal_io);
663 		fs->journal_io = NULL;
664 		free(fs->journal_name);
665 		fs->journal_name = NULL;
666 	}
667 
668 #ifndef USE_INODE_IO
669 	if (journal->j_inode)
670 		ext2fs_free_mem(&journal->j_inode);
671 #endif
672 	if (journal->j_fs_dev)
673 		ext2fs_free_mem(&journal->j_fs_dev);
674 	ext2fs_free_mem(&journal);
675 }
676 
677 /*
678  * This function makes sure that the superblock fields regarding the
679  * journal are consistent.
680  */
681 static errcode_t ext2fs_check_ext3_journal(ext2_filsys fs)
682 {
683 	struct ext2_super_block *sb = fs->super;
684 	journal_t *journal;
685 	int recover = ext2fs_has_feature_journal_needs_recovery(fs->super);
686 	errcode_t retval;
687 
688 	/* If we don't have any journal features, don't do anything more */
689 	if (!ext2fs_has_feature_journal(sb) &&
690 	    !recover && sb->s_journal_inum == 0 && sb->s_journal_dev == 0 &&
691 	    uuid_is_null(sb->s_journal_uuid))
692 		return 0;
693 
694 	retval = ext2fs_get_journal(fs, &journal);
695 	if (retval)
696 		return retval;
697 
698 	retval = ext2fs_journal_load(journal);
699 	if (retval)
700 		goto err;
701 
702 	/*
703 	 * We want to make the flags consistent here.  We will not leave with
704 	 * needs_recovery set but has_journal clear.  We can't get in a loop
705 	 * with -y, -n, or -p, only if a user isn't making up their mind.
706 	 */
707 	if (!ext2fs_has_feature_journal(sb)) {
708 		retval = EXT2_ET_JOURNAL_FLAGS_WRONG;
709 		goto err;
710 	}
711 
712 	if (ext2fs_has_feature_journal(sb) &&
713 	    !ext2fs_has_feature_journal_needs_recovery(sb) &&
714 	    journal->j_superblock->s_start != 0) {
715 		retval = EXT2_ET_JOURNAL_FLAGS_WRONG;
716 		goto err;
717 	}
718 
719 	/*
720 	 * If we don't need to do replay the journal, check to see if
721 	 * the journal's errno is set; if so, we need to mark the file
722 	 * system as being corrupt and clear the journal's s_errno.
723 	 */
724 	if (!ext2fs_has_feature_journal_needs_recovery(sb) &&
725 	    journal->j_superblock->s_errno) {
726 		fs->super->s_state |= EXT2_ERROR_FS;
727 		ext2fs_mark_super_dirty(fs);
728 		journal->j_superblock->s_errno = 0;
729 		ext2fs_journal_sb_csum_set(journal, journal->j_superblock);
730 		mark_buffer_dirty(journal->j_sb_buffer);
731 	}
732 
733 err:
734 	ext2fs_journal_release(fs, journal, 0, retval ? 1 : 0);
735 	return retval;
736 }
737 
738 static errcode_t recover_ext3_journal(ext2_filsys fs)
739 {
740 	journal_t *journal;
741 	errcode_t retval;
742 
743 	retval = jbd2_journal_init_revoke_record_cache();
744 	if (retval)
745 		return retval;
746 
747 	retval = jbd2_journal_init_revoke_table_cache();
748 	if (retval)
749 		return retval;
750 
751 	retval = ext2fs_get_journal(fs, &journal);
752 	if (retval)
753 		return retval;
754 
755 	retval = ext2fs_journal_load(journal);
756 	if (retval)
757 		goto errout;
758 
759 	retval = jbd2_journal_init_revoke(journal, 1024);
760 	if (retval)
761 		goto errout;
762 
763 	retval = -jbd2_journal_recover(journal);
764 	if (retval)
765 		goto errout;
766 
767 	if (journal->j_failed_commit) {
768 		journal->j_superblock->s_errno = -EINVAL;
769 		mark_buffer_dirty(journal->j_sb_buffer);
770 	}
771 
772 errout:
773 	jbd2_journal_destroy_revoke(journal);
774 	jbd2_journal_destroy_revoke_record_cache();
775 	jbd2_journal_destroy_revoke_table_cache();
776 	ext2fs_journal_release(fs, journal, 1, 0);
777 	return retval;
778 }
779 
780 errcode_t ext2fs_run_ext3_journal(ext2_filsys *fsp)
781 {
782 	ext2_filsys fs = *fsp;
783 	io_manager io_ptr = fs->io->manager;
784 	errcode_t	retval, recover_retval;
785 	io_stats	stats = 0;
786 	unsigned long long kbytes_written = 0;
787 	char *fsname;
788 	int fsflags;
789 	int fsblocksize;
790 
791 	if (!(fs->flags & EXT2_FLAG_RW))
792 		return EXT2_ET_FILE_RO;
793 
794 	if (fs->flags & EXT2_FLAG_DIRTY)
795 		ext2fs_flush(fs);	/* Force out any modifications */
796 
797 	recover_retval = recover_ext3_journal(fs);
798 
799 	/*
800 	 * Reload the filesystem context to get up-to-date data from disk
801 	 * because journal recovery will change the filesystem under us.
802 	 */
803 	if (fs->super->s_kbytes_written &&
804 	    fs->io->manager->get_stats)
805 		fs->io->manager->get_stats(fs->io, &stats);
806 	if (stats && stats->bytes_written)
807 		kbytes_written = stats->bytes_written >> 10;
808 
809 	ext2fs_mmp_stop(fs);
810 	fsname = fs->device_name;
811 	fs->device_name = NULL;
812 	fsflags = fs->flags;
813 	fsblocksize = fs->blocksize;
814 	ext2fs_free(fs);
815 	*fsp = NULL;
816 	retval = ext2fs_open(fsname, fsflags, 0, fsblocksize, io_ptr, fsp);
817 	ext2fs_free_mem(&fsname);
818 	if (retval)
819 		return retval;
820 
821 	fs = *fsp;
822 	fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
823 	fs->super->s_kbytes_written += kbytes_written;
824 
825 	/* Set the superblock flags */
826 	ext2fs_clear_recover(fs, recover_retval != 0);
827 
828 	/*
829 	 * Do one last sanity check, and propagate journal->s_errno to
830 	 * the EXT2_ERROR_FS flag in the fs superblock if needed.
831 	 */
832 	retval = ext2fs_check_ext3_journal(fs);
833 	return retval ? retval : recover_retval;
834 }
835 
836 errcode_t ext2fs_open_journal(ext2_filsys fs, journal_t **j)
837 {
838 	journal_t *journal;
839 	errcode_t retval;
840 
841 	retval = jbd2_journal_init_revoke_record_cache();
842 	if (retval)
843 		return retval;
844 
845 	retval = jbd2_journal_init_revoke_table_cache();
846 	if (retval)
847 		return retval;
848 
849 	retval = ext2fs_get_journal(fs, &journal);
850 	if (retval)
851 		return retval;
852 
853 	retval = ext2fs_journal_load(journal);
854 	if (retval)
855 		goto errout;
856 
857 	retval = jbd2_journal_init_revoke(journal, 1024);
858 	if (retval)
859 		goto errout;
860 
861 	if (journal->j_failed_commit) {
862 		journal->j_superblock->s_errno = -EINVAL;
863 		mark_buffer_dirty(journal->j_sb_buffer);
864 	}
865 
866 	*j = journal;
867 	return 0;
868 
869 errout:
870 	jbd2_journal_destroy_revoke(journal);
871 	jbd2_journal_destroy_revoke_record_cache();
872 	jbd2_journal_destroy_revoke_table_cache();
873 	ext2fs_journal_release(fs, journal, 1, 0);
874 	return retval;
875 }
876 
877 errcode_t ext2fs_close_journal(ext2_filsys fs, journal_t **j)
878 {
879 	journal_t *journal = *j;
880 
881 	jbd2_journal_destroy_revoke(journal);
882 	jbd2_journal_destroy_revoke_record_cache();
883 	jbd2_journal_destroy_revoke_table_cache();
884 	ext2fs_journal_release(fs, journal, 0, 0);
885 	*j = NULL;
886 
887 	return 0;
888 }
889 
890 void jbd2_commit_block_csum_set(journal_t *j, struct buffer_head *bh)
891 {
892 	struct commit_header *h;
893 	__u32 csum;
894 
895 	if (!jbd2_journal_has_csum_v2or3(j))
896 		return;
897 
898 	h = (struct commit_header *)(bh->b_data);
899 	h->h_chksum_type = 0;
900 	h->h_chksum_size = 0;
901 	h->h_chksum[0] = 0;
902 	csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
903 	h->h_chksum[0] = ext2fs_cpu_to_be32(csum);
904 }
905 
906 void jbd2_revoke_csum_set(journal_t *j, struct buffer_head *bh)
907 {
908 	jbd2_descr_block_csum_set(j, bh);
909 }
910 
911 void jbd2_descr_block_csum_set(journal_t *j, struct buffer_head *bh)
912 {
913 	struct jbd2_journal_block_tail *tail;
914 	__u32 csum;
915 
916 	if (!jbd2_journal_has_csum_v2or3(j))
917 		return;
918 
919 	tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize -
920 			sizeof(struct jbd2_journal_block_tail));
921 	tail->t_checksum = 0;
922 	csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
923 	tail->t_checksum = ext2fs_cpu_to_be32(csum);
924 }
925 
926 void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
927 			     struct buffer_head *bh, __u32 sequence)
928 {
929 	journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
930 	__u32 csum32;
931 	__be32 seq;
932 
933 	if (!jbd2_journal_has_csum_v2or3(j))
934 		return;
935 
936 	seq = ext2fs_cpu_to_be32(sequence);
937 	csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
938 	csum32 = jbd2_chksum(j, csum32, bh->b_data, bh->b_size);
939 
940 	if (jbd2_has_feature_csum3(j))
941 		tag3->t_checksum = ext2fs_cpu_to_be32(csum32);
942 	else
943 		tag->t_checksum = ext2fs_cpu_to_be16(csum32);
944 }
945 
946