1 /*
2  * e2undo.c - Replay an undo log onto an ext2/3/4 filesystem
3  *
4  * Copyright IBM Corporation, 2007
5  * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
6  *
7  * %Begin-Header%
8  * This file may be redistributed under the terms of the GNU Public
9  * License.
10  * %End-Header%
11  */
12 
13 #include "config.h"
14 #include <stdio.h>
15 #include <stdlib.h>
16 #ifdef HAVE_GETOPT_H
17 #include <getopt.h>
18 #endif
19 #include <fcntl.h>
20 #if HAVE_ERRNO_H
21 #include <errno.h>
22 #endif
23 #include <unistd.h>
24 #include <libgen.h>
25 #include "ext2fs/ext2fs.h"
26 #include "support/nls-enable.h"
27 
28 #undef DEBUG
29 
30 #ifdef DEBUG
31 # define dbg_printf(f, a...)  do {printf(f, ## a); fflush(stdout); } while (0)
32 #else
33 # define dbg_printf(f, a...)
34 #endif
35 
36 /*
37  * Undo file format: The file is cut up into undo_header.block_size blocks.
38  * The first block contains the header.
39  * The second block contains the superblock.
40  * There is then a repeating series of blocks as follows:
41  *   A key block, which contains undo_keys to map the following data blocks.
42  *   Data blocks
43  * (Note that there are pointers to the first key block and the sb, so this
44  * order isn't strictly necessary.)
45  */
46 #define E2UNDO_MAGIC "E2UNDO02"
47 #define KEYBLOCK_MAGIC 0xCADECADE
48 
49 #define E2UNDO_STATE_FINISHED	0x1	/* undo file is complete */
50 
51 #define E2UNDO_MIN_BLOCK_SIZE	1024	/* undo blocks are no less than 1KB */
52 #define E2UNDO_MAX_BLOCK_SIZE	1048576	/* undo blocks are no more than 1MB */
53 
54 struct undo_header {
55 	char magic[8];		/* "E2UNDO02" */
56 	__le64 num_keys;	/* how many keys? */
57 	__le64 super_offset;	/* where in the file is the superblock copy? */
58 	__le64 key_offset;	/* where do the key/data block chunks start? */
59 	__le32 block_size;	/* block size of the undo file */
60 	__le32 fs_block_size;	/* block size of the target device */
61 	__le32 sb_crc;		/* crc32c of the superblock */
62 	__le32 state;		/* e2undo state flags */
63 	__le32 f_compat;	/* compatible features (none so far) */
64 	__le32 f_incompat;	/* incompatible features (none so far) */
65 	__le32 f_rocompat;	/* ro compatible features (none so far) */
66 	__le32 pad32;		/* padding for fs_offset */
67 	__le64 fs_offset;	/* filesystem offset */
68 	__u8 padding[436];	/* padding */
69 	__le32 header_crc;	/* crc32c of the header (but not this field) */
70 };
71 
72 #define E2UNDO_MAX_EXTENT_BLOCKS	512	/* max extent size, in blocks */
73 
74 struct undo_key {
75 	__le64 fsblk;		/* where in the fs does the block go */
76 	__le32 blk_crc;		/* crc32c of the block */
77 	__le32 size;		/* how many bytes in this block? */
78 };
79 
80 struct undo_key_block {
81 	__le32 magic;		/* KEYBLOCK_MAGIC number */
82 	__le32 crc;		/* block checksum */
83 	__le64 reserved;	/* zero */
84 #if __GNUC_PREREQ (4, 8)
85 #pragma GCC diagnostic push
86 #pragma GCC diagnostic ignored "-Wpedantic"
87 #endif
88 	struct undo_key keys[0];	/* keys, which come immediately after */
89 #if __GNUC_PREREQ (4, 8)
90 #pragma GCC diagnostic pop
91 #endif
92 };
93 
94 struct undo_key_info {
95 	blk64_t fsblk;
96 	blk64_t fileblk;
97 	__u32 blk_crc;
98 	unsigned int size;
99 };
100 
101 struct undo_context {
102 	struct undo_header hdr;
103 	io_channel undo_file;
104 	unsigned int blocksize, fs_blocksize;
105 	blk64_t super_block;
106 	size_t num_keys;
107 	struct undo_key_info *keys;
108 };
109 #define KEYS_PER_BLOCK(d) (((d)->blocksize / sizeof(struct undo_key)) - 1)
110 
111 #define E2UNDO_FEATURE_COMPAT_FS_OFFSET 0x1	/* the filesystem offset */
112 
e2undo_has_feature_fs_offset(struct undo_header * header)113 static inline int e2undo_has_feature_fs_offset(struct undo_header *header) {
114 	return ext2fs_le32_to_cpu(header->f_compat) &
115 		E2UNDO_FEATURE_COMPAT_FS_OFFSET;
116 }
117 
118 static char *prg_name;
119 static char *undo_file;
120 
usage(void)121 static void usage(void)
122 {
123 	fprintf(stderr,
124 		_("Usage: %s [-f] [-h] [-n] [-o offset] [-v] [-z undo_file] <transaction file> <filesystem>\n"), prg_name);
125 	exit(1);
126 }
127 
dump_header(struct undo_header * hdr)128 static void dump_header(struct undo_header *hdr)
129 {
130 	printf("nr keys:\t%llu\n", ext2fs_le64_to_cpu(hdr->num_keys));
131 	printf("super block:\t%llu\n", ext2fs_le64_to_cpu(hdr->super_offset));
132 	printf("key block:\t%llu\n", ext2fs_le64_to_cpu(hdr->key_offset));
133 	printf("block size:\t%u\n", ext2fs_le32_to_cpu(hdr->block_size));
134 	printf("fs block size:\t%u\n", ext2fs_le32_to_cpu(hdr->fs_block_size));
135 	printf("super crc:\t0x%x\n", ext2fs_le32_to_cpu(hdr->sb_crc));
136 	printf("state:\t\t0x%x\n", ext2fs_le32_to_cpu(hdr->state));
137 	printf("compat:\t\t0x%x\n", ext2fs_le32_to_cpu(hdr->f_compat));
138 	printf("incompat:\t0x%x\n", ext2fs_le32_to_cpu(hdr->f_incompat));
139 	printf("rocompat:\t0x%x\n", ext2fs_le32_to_cpu(hdr->f_rocompat));
140 	if (e2undo_has_feature_fs_offset(hdr))
141 		printf("fs offset:\t%llu\n", ext2fs_le64_to_cpu(hdr->fs_offset));
142 	printf("header crc:\t0x%x\n", ext2fs_le32_to_cpu(hdr->header_crc));
143 }
144 
print_undo_mismatch(struct ext2_super_block * fs_super,struct ext2_super_block * undo_super)145 static void print_undo_mismatch(struct ext2_super_block *fs_super,
146 				struct ext2_super_block *undo_super)
147 {
148 	printf("%s",
149 	       _("The file system superblock doesn't match the undo file.\n"));
150 	if (memcmp(fs_super->s_uuid, undo_super->s_uuid,
151 		   sizeof(fs_super->s_uuid)))
152 		printf("%s", _("UUID does not match.\n"));
153 	if (fs_super->s_mtime != undo_super->s_mtime)
154 		printf("%s", _("Last mount time does not match.\n"));
155 	if (fs_super->s_wtime != undo_super->s_wtime)
156 		printf("%s", _("Last write time does not match.\n"));
157 	if (fs_super->s_kbytes_written != undo_super->s_kbytes_written)
158 		printf("%s", _("Lifetime write counter does not match.\n"));
159 }
160 
check_filesystem(struct undo_context * ctx,io_channel channel)161 static int check_filesystem(struct undo_context *ctx, io_channel channel)
162 {
163 	struct ext2_super_block super, *sb;
164 	char *buf;
165 	__u32 sb_crc;
166 	errcode_t retval;
167 
168 	io_channel_set_blksize(channel, SUPERBLOCK_OFFSET);
169 	retval = io_channel_read_blk64(channel, 1, -SUPERBLOCK_SIZE, &super);
170 	if (retval) {
171 		com_err(prg_name, retval,
172 			"%s", _("while reading filesystem superblock."));
173 		return retval;
174 	}
175 
176 	/*
177 	 * Compare the FS and the undo file superblock so that we can't apply
178 	 * e2undo "patches" out of order.
179 	 */
180 	retval = ext2fs_get_mem(ctx->blocksize, &buf);
181 	if (retval) {
182 		com_err(prg_name, retval, "%s", _("while allocating memory"));
183 		return retval;
184 	}
185 	retval = io_channel_read_blk64(ctx->undo_file, ctx->super_block,
186 				       -SUPERBLOCK_SIZE, buf);
187 	if (retval) {
188 		com_err(prg_name, retval, "%s", _("while fetching superblock"));
189 		goto out;
190 	}
191 	sb = (struct ext2_super_block *)buf;
192 	sb->s_magic = ~sb->s_magic;
193 	if (memcmp(&super, buf, sizeof(super))) {
194 		print_undo_mismatch(&super, (struct ext2_super_block *)buf);
195 		retval = -1;
196 		goto out;
197 	}
198 	sb_crc = ext2fs_crc32c_le(~0, (unsigned char *)buf, SUPERBLOCK_SIZE);
199 	if (ext2fs_le32_to_cpu(ctx->hdr.sb_crc) != sb_crc) {
200 		fprintf(stderr,
201 			_("Undo file superblock checksum doesn't match.\n"));
202 		retval = -1;
203 		goto out;
204 	}
205 
206 out:
207 	ext2fs_free_mem(&buf);
208 	return retval;
209 }
210 
key_compare(const void * a,const void * b)211 static int key_compare(const void *a, const void *b)
212 {
213 	const struct undo_key_info *ka, *kb;
214 
215 	ka = a;
216 	kb = b;
217 	return ka->fsblk - kb->fsblk;
218 }
219 
e2undo_setup_tdb(const char * name,io_manager * io_ptr)220 static int e2undo_setup_tdb(const char *name, io_manager *io_ptr)
221 {
222 	errcode_t retval = 0;
223 	const char *tdb_dir;
224 	char *tdb_file = NULL;
225 	char *dev_name, *tmp_name;
226 
227 	/* (re)open a specific undo file */
228 	if (undo_file && undo_file[0] != 0) {
229 		retval = set_undo_io_backing_manager(*io_ptr);
230 		if (retval)
231 			goto err;
232 		*io_ptr = undo_io_manager;
233 		retval = set_undo_io_backup_file(undo_file);
234 		if (retval)
235 			goto err;
236 		printf(_("Overwriting existing filesystem; this can be undone "
237 			 "using the command:\n"
238 			 "    e2undo %s %s\n\n"),
239 			 undo_file, name);
240 		return retval;
241 	}
242 
243 	/*
244 	 * Configuration via a conf file would be
245 	 * nice
246 	 */
247 	tdb_dir = getenv("E2FSPROGS_UNDO_DIR");
248 	if (!tdb_dir)
249 		tdb_dir = "/var/lib/e2fsprogs";
250 
251 	if (!strcmp(tdb_dir, "none") || (tdb_dir[0] == 0) ||
252 	    access(tdb_dir, W_OK))
253 		return 0;
254 
255 	tmp_name = strdup(name);
256 	if (!tmp_name)
257 		goto errout;
258 	dev_name = basename(tmp_name);
259 	tdb_file = malloc(strlen(tdb_dir) + 8 + strlen(dev_name) + 7 + 1);
260 	if (!tdb_file) {
261 		free(tmp_name);
262 		goto errout;
263 	}
264 	sprintf(tdb_file, "%s/e2undo-%s.e2undo", tdb_dir, dev_name);
265 	free(tmp_name);
266 
267 	if ((unlink(tdb_file) < 0) && (errno != ENOENT)) {
268 		retval = errno;
269 		com_err(prg_name, retval,
270 			_("while trying to delete %s"), tdb_file);
271 		goto errout;
272 	}
273 
274 	retval = set_undo_io_backing_manager(*io_ptr);
275 	if (retval)
276 		goto errout;
277 	*io_ptr = undo_io_manager;
278 	retval = set_undo_io_backup_file(tdb_file);
279 	if (retval)
280 		goto errout;
281 	printf(_("Overwriting existing filesystem; this can be undone "
282 		 "using the command:\n"
283 		 "    e2undo %s %s\n\n"),
284 		 tdb_file, name);
285 
286 	free(tdb_file);
287 	return 0;
288 errout:
289 	free(tdb_file);
290 err:
291 	com_err(prg_name, retval, "while trying to setup undo file\n");
292 	return retval;
293 }
294 
main(int argc,char * argv[])295 int main(int argc, char *argv[])
296 {
297 	int c, force = 0, dry_run = 0, verbose = 0, dump = 0;
298 	io_channel channel;
299 	errcode_t retval;
300 	int mount_flags, csum_error = 0, io_error = 0;
301 	size_t i, keys_per_block;
302 	char *device_name, *tdb_file;
303 	io_manager manager = unix_io_manager;
304 	struct undo_context undo_ctx;
305 	char *buf;
306 	struct undo_key_block *keyb;
307 	struct undo_key *dkey;
308 	struct undo_key_info *ikey;
309 	__u32 key_crc, blk_crc, hdr_crc;
310 	blk64_t lblk;
311 	ext2_filsys fs;
312 	__u64 offset = 0;
313 	char opt_offset_string[40] = { 0 };
314 
315 #ifdef ENABLE_NLS
316 	setlocale(LC_MESSAGES, "");
317 	setlocale(LC_CTYPE, "");
318 	bindtextdomain(NLS_CAT_NAME, LOCALEDIR);
319 	textdomain(NLS_CAT_NAME);
320 	set_com_err_gettext(gettext);
321 #endif
322 	add_error_table(&et_ext2_error_table);
323 
324 	prg_name = argv[0];
325 	while ((c = getopt(argc, argv, "fhno:vz:")) != EOF) {
326 		switch (c) {
327 		case 'f':
328 			force = 1;
329 			break;
330 		case 'h':
331 			dump = 1;
332 			break;
333 		case 'n':
334 			dry_run = 1;
335 			break;
336 		case 'o':
337 			offset = strtoull(optarg, &buf, 0);
338 			if (*buf) {
339 				com_err(prg_name, 0,
340 						_("illegal offset - %s"), optarg);
341 				exit(1);
342 			}
343 			/* used to indicate that an offset was specified */
344 			opt_offset_string[0] = 1;
345 			break;
346 		case 'v':
347 			verbose = 1;
348 			break;
349 		case 'z':
350 			undo_file = optarg;
351 			break;
352 		default:
353 			usage();
354 		}
355 	}
356 
357 	if (argc != optind + 2)
358 		usage();
359 
360 	tdb_file = argv[optind];
361 	device_name = argv[optind+1];
362 
363 	if (undo_file && strcmp(tdb_file, undo_file) == 0) {
364 		printf(_("Will not write to an undo file while replaying it.\n"));
365 		exit(1);
366 	}
367 
368 	/* Interpret the undo file */
369 	retval = manager->open(tdb_file, IO_FLAG_EXCLUSIVE,
370 			       &undo_ctx.undo_file);
371 	if (retval) {
372 		com_err(prg_name, errno,
373 				_("while opening undo file `%s'\n"), tdb_file);
374 		exit(1);
375 	}
376 	retval = io_channel_read_blk64(undo_ctx.undo_file, 0,
377 				       -(int)sizeof(undo_ctx.hdr),
378 				       &undo_ctx.hdr);
379 	if (retval) {
380 		com_err(prg_name, retval, _("while reading undo file"));
381 		exit(1);
382 	}
383 	if (memcmp(undo_ctx.hdr.magic, E2UNDO_MAGIC,
384 		    sizeof(undo_ctx.hdr.magic))) {
385 		fprintf(stderr, _("%s: Not an undo file.\n"), tdb_file);
386 		exit(1);
387 	}
388 	if (dump) {
389 		dump_header(&undo_ctx.hdr);
390 		exit(1);
391 	}
392 	hdr_crc = ext2fs_crc32c_le(~0, (unsigned char *)&undo_ctx.hdr,
393 				   sizeof(struct undo_header) -
394 				   sizeof(__u32));
395 	if (!force && ext2fs_le32_to_cpu(undo_ctx.hdr.header_crc) != hdr_crc) {
396 		fprintf(stderr, _("%s: Header checksum doesn't match.\n"),
397 			tdb_file);
398 		exit(1);
399 	}
400 	undo_ctx.blocksize = ext2fs_le32_to_cpu(undo_ctx.hdr.block_size);
401 	undo_ctx.fs_blocksize = ext2fs_le32_to_cpu(undo_ctx.hdr.fs_block_size);
402 	if (undo_ctx.blocksize == 0 || undo_ctx.fs_blocksize == 0) {
403 		fprintf(stderr, _("%s: Corrupt undo file header.\n"), tdb_file);
404 		exit(1);
405 	}
406 	if (!force && undo_ctx.blocksize > E2UNDO_MAX_BLOCK_SIZE) {
407 		fprintf(stderr, _("%s: Undo block size too large.\n"),
408 			tdb_file);
409 		exit(1);
410 	}
411 	if (!force && undo_ctx.blocksize < E2UNDO_MIN_BLOCK_SIZE) {
412 		fprintf(stderr, _("%s: Undo block size too small.\n"),
413 			tdb_file);
414 		exit(1);
415 	}
416 	undo_ctx.super_block = ext2fs_le64_to_cpu(undo_ctx.hdr.super_offset);
417 	undo_ctx.num_keys = ext2fs_le64_to_cpu(undo_ctx.hdr.num_keys);
418 	io_channel_set_blksize(undo_ctx.undo_file, undo_ctx.blocksize);
419 	/*
420 	 * Do not compare undo_ctx.hdr.f_compat with the available compatible
421 	 * features set, because a "missing" compatible feature should
422 	 * not cause any problems.
423 	 */
424 	if (!force && (undo_ctx.hdr.f_incompat || undo_ctx.hdr.f_rocompat)) {
425 		fprintf(stderr, _("%s: Unknown undo file feature set.\n"),
426 			tdb_file);
427 		exit(1);
428 	}
429 
430 	/* open the fs */
431 	retval = ext2fs_check_if_mounted(device_name, &mount_flags);
432 	if (retval) {
433 		com_err(prg_name, retval, _("Error while determining whether "
434 				"%s is mounted."), device_name);
435 		exit(1);
436 	}
437 
438 	if (mount_flags & EXT2_MF_MOUNTED) {
439 		com_err(prg_name, retval, "%s", _("e2undo should only be run "
440 						"on unmounted filesystems"));
441 		exit(1);
442 	}
443 
444 	if (undo_file) {
445 		retval = e2undo_setup_tdb(device_name, &manager);
446 		if (retval)
447 			exit(1);
448 	}
449 
450 	retval = manager->open(device_name,
451 			       IO_FLAG_EXCLUSIVE | (dry_run ? 0 : IO_FLAG_RW),
452 			       &channel);
453 	if (retval) {
454 		com_err(prg_name, retval,
455 				_("while opening `%s'"), device_name);
456 		exit(1);
457 	}
458 
459 	if (*opt_offset_string || e2undo_has_feature_fs_offset(&undo_ctx.hdr)) {
460 		if (!*opt_offset_string)
461 			offset = ext2fs_le64_to_cpu(undo_ctx.hdr.fs_offset);
462 		retval = snprintf(opt_offset_string, sizeof(opt_offset_string),
463 						  "offset=%llu", offset);
464 		if ((size_t) retval >= sizeof(opt_offset_string)) {
465 			/* should not happen... */
466 			com_err(prg_name, 0, _("specified offset is too large"));
467 			exit(1);
468 		}
469 		io_channel_set_options(channel, opt_offset_string);
470 	}
471 
472 	if (!force && check_filesystem(&undo_ctx, channel))
473 		exit(1);
474 
475 	/* prepare to read keys */
476 	retval = ext2fs_get_mem(sizeof(struct undo_key_info) * undo_ctx.num_keys,
477 				&undo_ctx.keys);
478 	if (retval) {
479 		com_err(prg_name, retval, "%s", _("while allocating memory"));
480 		exit(1);
481 	}
482 	ikey = undo_ctx.keys;
483 	retval = ext2fs_get_mem(undo_ctx.blocksize, &keyb);
484 	if (retval) {
485 		com_err(prg_name, retval, "%s", _("while allocating memory"));
486 		exit(1);
487 	}
488 	retval = ext2fs_get_mem(E2UNDO_MAX_EXTENT_BLOCKS * undo_ctx.blocksize,
489 				&buf);
490 	if (retval) {
491 		com_err(prg_name, retval, "%s", _("while allocating memory"));
492 		exit(1);
493 	}
494 
495 	/* load keys */
496 	keys_per_block = KEYS_PER_BLOCK(&undo_ctx);
497 	lblk = ext2fs_le64_to_cpu(undo_ctx.hdr.key_offset);
498 	dbg_printf("nr_keys=%lu, kpb=%zu, blksz=%u\n",
499 		   undo_ctx.num_keys, keys_per_block, undo_ctx.blocksize);
500 	for (i = 0; i < undo_ctx.num_keys; i += keys_per_block) {
501 		size_t j, max_j;
502 		__le32 crc;
503 
504 		retval = io_channel_read_blk64(undo_ctx.undo_file,
505 					       lblk, 1, keyb);
506 		if (retval) {
507 			com_err(prg_name, retval, "%s", _("while reading keys"));
508 			if (force) {
509 				io_error = 1;
510 				undo_ctx.num_keys = i - 1;
511 				break;
512 			}
513 			exit(1);
514 		}
515 
516 		/* check keys */
517 		if (!force &&
518 		    ext2fs_le32_to_cpu(keyb->magic) != KEYBLOCK_MAGIC) {
519 			fprintf(stderr, _("%s: wrong key magic at %llu\n"),
520 				tdb_file, lblk);
521 			exit(1);
522 		}
523 		crc = keyb->crc;
524 		keyb->crc = 0;
525 		key_crc = ext2fs_crc32c_le(~0, (unsigned char *)keyb,
526 					   undo_ctx.blocksize);
527 		if (!force && ext2fs_le32_to_cpu(crc) != key_crc) {
528 			fprintf(stderr,
529 				_("%s: key block checksum error at %llu.\n"),
530 				tdb_file, lblk);
531 			exit(1);
532 		}
533 
534 		/* load keys from key block */
535 		lblk++;
536 		max_j = undo_ctx.num_keys - i;
537 		if (max_j > keys_per_block)
538 			max_j = keys_per_block;
539 		for (j = 0, dkey = keyb->keys;
540 		     j < max_j;
541 		     j++, ikey++, dkey++) {
542 			ikey->fsblk = ext2fs_le64_to_cpu(dkey->fsblk);
543 			ikey->fileblk = lblk;
544 			ikey->blk_crc = ext2fs_le32_to_cpu(dkey->blk_crc);
545 			ikey->size = ext2fs_le32_to_cpu(dkey->size);
546 			lblk += (ikey->size + undo_ctx.blocksize - 1) /
547 				undo_ctx.blocksize;
548 
549 			if (E2UNDO_MAX_EXTENT_BLOCKS * undo_ctx.blocksize <
550 			    ikey->size) {
551 				com_err(prg_name, retval,
552 					_("%s: block %llu is too long."),
553 					tdb_file, ikey->fsblk);
554 				exit(1);
555 			}
556 
557 			/* check each block's crc */
558 			retval = io_channel_read_blk64(undo_ctx.undo_file,
559 						       ikey->fileblk,
560 						       -(int)ikey->size,
561 						       buf);
562 			if (retval) {
563 				com_err(prg_name, retval,
564 					_("while fetching block %llu."),
565 					ikey->fileblk);
566 				if (!force)
567 					exit(1);
568 				io_error = 1;
569 				continue;
570 			}
571 
572 			blk_crc = ext2fs_crc32c_le(~0, (unsigned char *)buf,
573 						   ikey->size);
574 			if (blk_crc != ikey->blk_crc) {
575 				fprintf(stderr,
576 					_("checksum error in filesystem block "
577 					  "%llu (undo blk %llu)\n"),
578 					ikey->fsblk, ikey->fileblk);
579 				if (!force)
580 					exit(1);
581 				csum_error = 1;
582 			}
583 		}
584 	}
585 	ext2fs_free_mem(&keyb);
586 
587 	/* sort keys in fs block order */
588 	qsort(undo_ctx.keys, undo_ctx.num_keys, sizeof(struct undo_key_info),
589 	      key_compare);
590 
591 	/* replay */
592 	io_channel_set_blksize(channel, undo_ctx.fs_blocksize);
593 	for (i = 0, ikey = undo_ctx.keys; i < undo_ctx.num_keys; i++, ikey++) {
594 		retval = io_channel_read_blk64(undo_ctx.undo_file,
595 					       ikey->fileblk,
596 					       -(int)ikey->size,
597 					       buf);
598 		if (retval) {
599 			com_err(prg_name, retval,
600 				_("while fetching block %llu."),
601 				ikey->fileblk);
602 			io_error = 1;
603 			continue;
604 		}
605 
606 		if (verbose)
607 			printf("Replayed block of size %u from %llu to %llu\n",
608 				ikey->size, ikey->fileblk, ikey->fsblk);
609 		if (dry_run)
610 			continue;
611 		retval = io_channel_write_blk64(channel, ikey->fsblk,
612 						-(int)ikey->size, buf);
613 		if (retval) {
614 			com_err(prg_name, retval,
615 				_("while writing block %llu."), ikey->fsblk);
616 			io_error = 1;
617 		}
618 	}
619 
620 	if (csum_error)
621 		fprintf(stderr, _("Undo file corruption; run e2fsck NOW!\n"));
622 	if (io_error)
623 		fprintf(stderr, _("IO error during replay; run e2fsck NOW!\n"));
624 	if (!(ext2fs_le32_to_cpu(undo_ctx.hdr.state) & E2UNDO_STATE_FINISHED)) {
625 		force = 1;
626 		fprintf(stderr, _("Incomplete undo record; run e2fsck.\n"));
627 	}
628 	ext2fs_free_mem(&buf);
629 	ext2fs_free_mem(&undo_ctx.keys);
630 	io_channel_close(channel);
631 
632 	/* If there were problems, try to force a fsck */
633 	if (!dry_run && (force || csum_error || io_error)) {
634 		retval = ext2fs_open2(device_name, NULL,
635 				   EXT2_FLAG_RW | EXT2_FLAG_64BITS, 0, 0,
636 				   manager, &fs);
637 		if (retval)
638 			goto out;
639 		fs->super->s_state &= ~EXT2_VALID_FS;
640 		if (csum_error || io_error)
641 			fs->super->s_state |= EXT2_ERROR_FS;
642 		ext2fs_mark_super_dirty(fs);
643 		ext2fs_close_free(&fs);
644 	}
645 
646 out:
647 	io_channel_close(undo_ctx.undo_file);
648 
649 	return csum_error;
650 }
651