summaryrefslogtreecommitdiff
path: root/util-linux/fsck_minix.c
blob: cdd3060317e4289dbe5b37ab8499333c5210152e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
/* vi: set sw=4 ts=4: */
/*
 * fsck.c - a file system consistency checker for Linux.
 *
 * (C) 1991, 1992 Linus Torvalds.
 *
 * Licensed under GPLv2, see file LICENSE in this tarball for details.
 */

/*
 * 09.11.91  -  made the first rudimentary functions
 *
 * 10.11.91  -  updated, does checking, no repairs yet.
 *		Sent out to the mailing-list for testing.
 *
 * 14.11.91  -	Testing seems to have gone well. Added some
 *		correction-code, and changed some functions.
 *
 * 15.11.91  -  More correction code. Hopefully it notices most
 *		cases now, and tries to do something about them.
 *
 * 16.11.91  -  More corrections (thanks to Mika Jalava). Most
 *		things seem to work now. Yeah, sure.
 *
 *
 * 19.04.92  -	Had to start over again from this old version, as a
 *		kernel bug ate my enhanced fsck in february.
 *
 * 28.02.93  -	added support for different directory entry sizes..
 *
 * Sat Mar  6 18:59:42 1993, faith@cs.unc.edu: Output namelen with
 *                           superblock information
 *
 * Sat Oct  9 11:17:11 1993, faith@cs.unc.edu: make exit status conform
 *                           to that required by fsutil
 *
 * Mon Jan  3 11:06:52 1994 - Dr. Wettstein (greg%wind.uucp@plains.nodak.edu)
 *			      Added support for file system valid flag.  Also
 *			      added program_version variable and output of
 *			      program name and version number when program
 *			      is executed.
 *
 * 30.10.94 - added support for v2 filesystem
 *            (Andreas Schwab, schwab@issan.informatik.uni-dortmund.de)
 *
 * 10.12.94  -  added test to prevent checking of mounted fs adapted
 *              from Theodore Ts'o's (tytso@athena.mit.edu) e2fsck
 *              program.  (Daniel Quinlan, quinlan@yggdrasil.com)
 *
 * 01.07.96  - Fixed the v2 fs stuff to use the right #defines and such
 *	       for modern libcs (janl@math.uio.no, Nicolai Langfeldt)
 *
 * 02.07.96  - Added C bit fiddling routines from rmk@ecs.soton.ac.uk
 *             (Russell King).  He made them for ARM.  It would seem
 *	       that the ARM is powerful enough to do this in C whereas
 *             i386 and m64k must use assembly to get it fast >:-)
 *	       This should make minix fsck system-independent.
 *	       (janl@math.uio.no, Nicolai Langfeldt)
 *
 * 04.11.96  - Added minor fixes from Andreas Schwab to avoid compiler
 *             warnings.  Added mc68k bitops from
 *	       Joerg Dorchain <dorchain@mpi-sb.mpg.de>.
 *
 * 06.11.96  - Added v2 code submitted by Joerg Dorchain, but written by
 *             Andreas Schwab.
 *
 * 1999-02-22 Arkadiusz Mickiewicz <misiek@misiek.eu.org>
 * - added Native Language Support
 *
 *
 * I've had no time to add comments - hopefully the function names
 * are comments enough. As with all file system checkers, this assumes
 * the file system is quiescent - don't use it on a mounted device
 * unless you can be sure nobody is writing to it (and remember that the
 * kernel can write to it when it searches for files).
 *
 * Usage: fsck [-larvsm] device
 *	-l for a listing of all the filenames
 *	-a for automatic repairs (not implemented)
 *	-r for repairs (interactive) (not implemented)
 *	-v for verbose (tells how many files)
 *	-s for superblock info
 *	-m for minix-like "mode not cleared" warnings
 *	-f force filesystem check even if filesystem marked as valid
 *
 * The device may be a block device or a image of one, but this isn't
 * enforced (but it's not much fun on a character device :-).
 */

#include <mntent.h>
#include "libbb.h"
#include "minix.h"

#ifndef BLKGETSIZE
#define BLKGETSIZE _IO(0x12,96)    /* return device size */
#endif

struct BUG_bad_inode_size {
	char BUG_bad_inode1_size[(INODE_SIZE1 * MINIX1_INODES_PER_BLOCK != BLOCK_SIZE) ? -1 : 1];
#if ENABLE_FEATURE_MINIX2
	char BUG_bad_inode2_size[(INODE_SIZE2 * MINIX2_INODES_PER_BLOCK != BLOCK_SIZE) ? -1 : 1];
#endif
};

enum {
#ifdef UNUSED
	MINIX1_LINK_MAX = 250,
	MINIX2_LINK_MAX = 65530,
	MINIX_I_MAP_SLOTS = 8,
	MINIX_Z_MAP_SLOTS = 64,
	MINIX_V1 = 0x0001,      /* original minix fs */
	MINIX_V2 = 0x0002,      /* minix V2 fs */
#endif
	MINIX_NAME_MAX = 255,         /* # chars in a file name */
};


#if !ENABLE_FEATURE_MINIX2
enum { version2 = 0 };
#endif

enum { MAX_DEPTH = 32 };

enum { dev_fd = 3 };

struct globals {
#if ENABLE_FEATURE_MINIX2
	smallint version2;
#endif
	smallint changed;  /* is filesystem modified? */
	smallint errors_uncorrected;  /* flag if some error was not corrected */
	smallint termios_set;
	smallint dirsize;
	smallint namelen;
	const char *device_name;
	int directory, regular, blockdev, chardev, links, symlinks, total;
	char *inode_buffer;

	char *inode_map;
	char *zone_map;

	unsigned char *inode_count;
	unsigned char *zone_count;

	/* File-name data */
	int name_depth;
	char *name_component[MAX_DEPTH+1];

	/* Bigger stuff */
	struct termios sv_termios;
	char superblock_buffer[BLOCK_SIZE];
	char add_zone_ind_blk[BLOCK_SIZE];
	char add_zone_dind_blk[BLOCK_SIZE];
	IF_FEATURE_MINIX2(char add_zone_tind_blk[BLOCK_SIZE];)
	char check_file_blk[BLOCK_SIZE];

	/* File-name data */
	char current_name[MAX_DEPTH * MINIX_NAME_MAX];
};

#define G (*ptr_to_globals)
#if ENABLE_FEATURE_MINIX2
#define version2           (G.version2           )
#endif
#define changed            (G.changed            )
#define errors_uncorrected (G.errors_uncorrected )
#define termios_set        (G.termios_set        )
#define dirsize            (G.dirsize            )
#define namelen            (G.namelen            )
#define device_name        (G.device_name        )
#define directory          (G.directory          )
#define regular            (G.regular            )
#define blockdev           (G.blockdev           )
#define chardev            (G.chardev            )
#define links              (G.links              )
#define symlinks           (G.symlinks           )
#define total              (G.total              )
#define inode_buffer       (G.inode_buffer       )
#define inode_map          (G.inode_map          )
#define zone_map           (G.zone_map           )
#define inode_count        (G.inode_count        )
#define zone_count         (G.zone_count         )
#define name_depth         (G.name_depth         )
#define name_component     (G.name_component     )
#define sv_termios         (G.sv_termios         )
#define superblock_buffer  (G.superblock_buffer )
#define add_zone_ind_blk   (G.add_zone_ind_blk   )
#define add_zone_dind_blk  (G.add_zone_dind_blk  )
#define add_zone_tind_blk  (G.add_zone_tind_blk  )
#define check_file_blk     (G.check_file_blk     )
#define current_name       (G.current_name       )
#define INIT_G() do { \
	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
	dirsize = 16; \
	namelen = 14; \
	current_name[0] = '/'; \
	/*current_name[1] = '\0';*/ \
	name_component[0] = &current_name[0]; \
} while (0)


#define OPTION_STR "larvsmf"
enum {
	OPT_l = (1 << 0),
	OPT_a = (1 << 1),
	OPT_r = (1 << 2),
	OPT_v = (1 << 3),
	OPT_s = (1 << 4),
	OPT_w = (1 << 5),
	OPT_f = (1 << 6),
};
#define OPT_list      (option_mask32 & OPT_l)
#define OPT_automatic (option_mask32 & OPT_a)
#define OPT_repair    (option_mask32 & OPT_r)
#define OPT_verbose   (option_mask32 & OPT_v)
#define OPT_show      (option_mask32 & OPT_s)
#define OPT_warn_mode (option_mask32 & OPT_w)
#define OPT_force     (option_mask32 & OPT_f)
/* non-automatic repairs requested? */
#define OPT_manual    ((option_mask32 & (OPT_a|OPT_r)) == OPT_r)


#define Inode1 (((struct minix1_inode *) inode_buffer)-1)
#define Inode2 (((struct minix2_inode *) inode_buffer)-1)

#define Super (*(struct minix_superblock *)(superblock_buffer))

#if ENABLE_FEATURE_MINIX2
# define ZONES    ((unsigned)(version2 ? Super.s_zones : Super.s_nzones))
#else
# define ZONES    ((unsigned)(Super.s_nzones))
#endif
#define INODES    ((unsigned)Super.s_ninodes)
#define IMAPS     ((unsigned)Super.s_imap_blocks)
#define ZMAPS     ((unsigned)Super.s_zmap_blocks)
#define FIRSTZONE ((unsigned)Super.s_firstdatazone)
#define ZONESIZE  ((unsigned)Super.s_log_zone_size)
#define MAXSIZE   ((unsigned)Super.s_max_size)
#define MAGIC     (Super.s_magic)

/* gcc likes this more (code is smaller) than macro variant */
static ALWAYS_INLINE unsigned div_roundup(unsigned size, unsigned n)
{
	return (size + n-1) / n;
}

#if !ENABLE_FEATURE_MINIX2
#define INODE_BLOCKS            div_roundup(INODES, MINIX1_INODES_PER_BLOCK)
#else
#define INODE_BLOCKS            div_roundup(INODES, \
                                (version2 ? MINIX2_INODES_PER_BLOCK : MINIX1_INODES_PER_BLOCK))
#endif

#define INODE_BUFFER_SIZE       (INODE_BLOCKS * BLOCK_SIZE)
#define NORM_FIRSTZONE          (2 + IMAPS + ZMAPS + INODE_BLOCKS)

/* Before you ask "where they come from?": */
/* setbit/clrbit are supplied by sys/param.h */

static int minix_bit(const char *a, unsigned i)
{
	return (a[i >> 3] & (1<<(i & 7)));
}

static void minix_setbit(char *a, unsigned i)
{
	setbit(a, i);
	changed = 1;
}
static void minix_clrbit(char *a, unsigned i)
{
	clrbit(a, i);
	changed = 1;
}

/* Note: do not assume 0/1, it is 0/nonzero */
#define zone_in_use(x)  (minix_bit(zone_map,(x)-FIRSTZONE+1))
#define inode_in_use(x) (minix_bit(inode_map,(x)))

#define mark_inode(x)   (minix_setbit(inode_map,(x)))
#define unmark_inode(x) (minix_clrbit(inode_map,(x)))

#define mark_zone(x)    (minix_setbit(zone_map,(x)-FIRSTZONE+1))
#define unmark_zone(x)  (minix_clrbit(zone_map,(x)-FIRSTZONE+1))


static void recursive_check(unsigned ino);
#if ENABLE_FEATURE_MINIX2
static void recursive_check2(unsigned ino);
#endif

static void die(const char *str) NORETURN;
static void die(const char *str)
{
	if (termios_set)
		tcsetattr_stdin_TCSANOW(&sv_termios);
	bb_error_msg_and_die("%s", str);
}

static void push_filename(const char *name)
{
	//  /dir/dir/dir/file
	//  ^   ^   ^
	// [0] [1] [2] <-name_component[i]
	if (name_depth < MAX_DEPTH) {
		int len;
		char *p = name_component[name_depth];
		*p++ = '/';
		len = sprintf(p, "%.*s", namelen, name);
		name_component[name_depth + 1] = p + len;
	}
	name_depth++;
}

static void pop_filename(void)
{
	name_depth--;
	if (name_depth < MAX_DEPTH) {
		*name_component[name_depth] = '\0';
		if (!name_depth) {
			current_name[0] = '/';
			current_name[1] = '\0';
		}
	}
}

static int ask(const char *string, int def)
{
	int c;

	if (!OPT_repair) {
		bb_putchar('\n');
		errors_uncorrected = 1;
		return 0;
	}
	if (OPT_automatic) {
		bb_putchar('\n');
		if (!def)
			errors_uncorrected = 1;
		return def;
	}
	printf(def ? "%s (y/n)? " : "%s (n/y)? ", string);
	for (;;) {
		fflush(NULL);
		c = getchar();
		if (c == EOF) {
			if (!def)
				errors_uncorrected = 1;
			return def;
		}
		if (c == '\n')
			break;
		c |= 0x20; /* tolower */
		if (c == 'y') {
			def = 1;
			break;
		}
		if (c == 'n') {
			def = 0;
			break;
		}
	}
	if (def)
		printf("y\n");
	else {
		printf("n\n");
		errors_uncorrected = 1;
	}
	return def;
}

/*
 * Make certain that we aren't checking a filesystem that is on a
 * mounted partition.  Code adapted from e2fsck, Copyright (C) 1993,
 * 1994 Theodore Ts'o.  Also licensed under GPL.
 */
static void check_mount(void)
{
	if (find_mount_point(device_name, 0)) {
		int cont;
#if ENABLE_FEATURE_MTAB_SUPPORT
		/*
		 * If the root is mounted read-only, then /etc/mtab is
		 * probably not correct; so we won't issue a warning based on
		 * it.
		 */
		int fd = open(bb_path_mtab_file, O_RDWR);

		if (fd < 0 && errno == EROFS)
			return;
		close(fd);
#endif
		printf("%s is mounted. ", device_name);
		cont = 0;
		if (isatty(0) && isatty(1))
			cont = ask("Do you really want to continue", 0);
		if (!cont) {
			printf("Check aborted\n");
			exit(EXIT_SUCCESS);
		}
	}
}

/*
 * check_zone_nr checks to see that *nr is a valid zone nr. If it
 * isn't, it will possibly be repaired. Check_zone_nr sets *corrected
 * if an error was corrected, and returns the zone (0 for no zone
 * or a bad zone-number).
 */
static int check_zone_nr2(uint32_t *nr, smallint *corrected)
{
	const char *msg;
	if (!*nr)
		return 0;
	if (*nr < FIRSTZONE)
		msg = "< FIRSTZONE";
	else if (*nr >= ZONES)
		msg = ">= ZONES";
	else
		return *nr;
	printf("Zone nr %s in file '%s'. ", msg, current_name);
	if (ask("Remove block", 1)) {
		*nr = 0;
		*corrected = 1;
	}
	return 0;
}

static int check_zone_nr(uint16_t *nr, smallint *corrected)
{
	uint32_t nr32 = *nr;
	int r = check_zone_nr2(&nr32, corrected);
	*nr = (uint16_t)nr32;
	return r;
}

/*
 * read-block reads block nr into the buffer at addr.
 */
static void read_block(unsigned nr, void *addr)
{
	if (!nr) {
		memset(addr, 0, BLOCK_SIZE);
		return;
	}
	xlseek(dev_fd, BLOCK_SIZE * nr, SEEK_SET);
	if (BLOCK_SIZE != full_read(dev_fd, addr, BLOCK_SIZE)) {
		printf("%s: bad block %u in file '%s'\n",
				bb_msg_read_error, nr, current_name);
		errors_uncorrected = 1;
		memset(addr, 0, BLOCK_SIZE);
	}
}

/*
 * write_block writes block nr to disk.
 */
static void write_block(unsigned nr, void *addr)
{
	if (!nr)
		return;
	if (nr < FIRSTZONE || nr >= ZONES) {
		printf("Internal error: trying to write bad block\n"
			   "Write request ignored\n");
		errors_uncorrected = 1;
		return;
	}
	xlseek(dev_fd, BLOCK_SIZE * nr, SEEK_SET);
	if (BLOCK_SIZE != full_write(dev_fd, addr, BLOCK_SIZE)) {
		printf("%s: bad block %u in file '%s'\n",
				bb_msg_write_error, nr, current_name);
		errors_uncorrected = 1;
	}
}

/*
 * map_block calculates the absolute block nr of a block in a file.
 * It sets 'changed' if the inode has needed changing, and re-writes
 * any indirect blocks with errors.
 */
static int map_block(struct minix1_inode *inode, unsigned blknr)
{
	uint16_t ind[BLOCK_SIZE >> 1];
	int block, result;
	smallint blk_chg;

	if (blknr < 7)
		return check_zone_nr(inode->i_zone + blknr, &changed);
	blknr -= 7;
	if (blknr < 512) {
		block = check_zone_nr(inode->i_zone + 7, &changed);
		goto common;
	}
	blknr -= 512;
	block = check_zone_nr(inode->i_zone + 8, &changed);
	read_block(block, ind); /* double indirect */
	blk_chg = 0;
	result = check_zone_nr(&ind[blknr / 512], &blk_chg);
	if (blk_chg)
		write_block(block, ind);
	block = result;
 common:
	read_block(block, ind);
	blk_chg = 0;
	result = check_zone_nr(&ind[blknr % 512], &blk_chg);
	if (blk_chg)
		write_block(block, ind);
	return result;
}

#if ENABLE_FEATURE_MINIX2
static int map_block2(struct minix2_inode *inode, unsigned blknr)
{
	uint32_t ind[BLOCK_SIZE >> 2];
	int block, result;
	smallint blk_chg;

	if (blknr < 7)
		return check_zone_nr2(inode->i_zone + blknr, &changed);
	blknr -= 7;
	if (blknr < 256) {
		block = check_zone_nr2(inode->i_zone + 7, &changed);
		goto common2;
	}
	blknr -= 256;
	if (blknr < 256 * 256) {
		block = check_zone_nr2(inode->i_zone + 8, &changed);
		goto common1;
	}
	blknr -= 256 * 256;
	block = check_zone_nr2(inode->i_zone + 9, &changed);
	read_block(block, ind); /* triple indirect */
	blk_chg = 0;
	result = check_zone_nr2(&ind[blknr / (256 * 256)], &blk_chg);
	if (blk_chg)
		write_block(block, ind);
	block = result;
 common1:
	read_block(block, ind); /* double indirect */
	blk_chg = 0;
	result = check_zone_nr2(&ind[(blknr / 256) % 256], &blk_chg);
	if (blk_chg)
		write_block(block, ind);
	block = result;
 common2:
	read_block(block, ind);
	blk_chg = 0;
	result = check_zone_nr2(&ind[blknr % 256], &blk_chg);
	if (blk_chg)
		write_block(block, ind);
	return result;
}
#endif

static void write_superblock(void)
{
	/*
	 * Set the state of the filesystem based on whether or not there
	 * are uncorrected errors.  The filesystem valid flag is
	 * unconditionally set if we get this far.
	 */
	Super.s_state |= MINIX_VALID_FS | MINIX_ERROR_FS;
	if (!errors_uncorrected)
		Super.s_state &= ~MINIX_ERROR_FS;

	xlseek(dev_fd, BLOCK_SIZE, SEEK_SET);
	if (BLOCK_SIZE != full_write(dev_fd, superblock_buffer, BLOCK_SIZE))
		die("cannot write superblock");
}

static void write_tables(void)
{
	write_superblock();

	if (IMAPS * BLOCK_SIZE != write(dev_fd, inode_map, IMAPS * BLOCK_SIZE))
		die("cannot write inode map");
	if (ZMAPS * BLOCK_SIZE != write(dev_fd, zone_map, ZMAPS * BLOCK_SIZE))
		die("cannot write zone map");
	if (INODE_BUFFER_SIZE != write(dev_fd, inode_buffer, INODE_BUFFER_SIZE))
		die("cannot write inodes");
}

static void get_dirsize(void)
{
	int block;
	char blk[BLOCK_SIZE];
	int size;

#if ENABLE_FEATURE_MINIX2
	if (version2)
		block = Inode2[MINIX_ROOT_INO].i_zone[0];
	else
#endif
		block = Inode1[MINIX_ROOT_INO].i_zone[0];
	read_block(block, blk);
	for (size = 16; size < BLOCK_SIZE; size <<= 1) {
		if (strcmp(blk + size + 2, "..") == 0) {
			dirsize = size;
			namelen = size - 2;
			return;
		}
	}
	/* use defaults */
}

static void read_superblock(void)
{
	xlseek(dev_fd, BLOCK_SIZE, SEEK_SET);
	if (BLOCK_SIZE != full_read(dev_fd, superblock_buffer, BLOCK_SIZE))
		die("cannot read superblock");
	/* already initialized to:
	namelen = 14;
	dirsize = 16;
	version2 = 0;
	*/
	if (MAGIC == MINIX1_SUPER_MAGIC) {
	} else if (MAGIC == MINIX1_SUPER_MAGIC2) {
		namelen = 30;
		dirsize = 32;
#if ENABLE_FEATURE_MINIX2
	} else if (MAGIC == MINIX2_SUPER_MAGIC) {
		version2 = 1;
	} else if (MAGIC == MINIX2_SUPER_MAGIC2) {
		namelen = 30;
		dirsize = 32;
		version2 = 1;
#endif
	} else
		die("bad magic number in superblock");
	if (ZONESIZE != 0 || BLOCK_SIZE != 1024)
		die("only 1k blocks/zones supported");
	if (IMAPS * BLOCK_SIZE * 8 < INODES + 1)
		die("bad s_imap_blocks field in superblock");
	if (ZMAPS * BLOCK_SIZE * 8 < ZONES - FIRSTZONE + 1)
		die("bad s_zmap_blocks field in superblock");
}

static void read_tables(void)
{
	inode_map = xzalloc(IMAPS * BLOCK_SIZE);
	zone_map = xzalloc(ZMAPS * BLOCK_SIZE);
	inode_buffer = xmalloc(INODE_BUFFER_SIZE);
	inode_count = xmalloc(INODES + 1);
	zone_count = xmalloc(ZONES);
	if (IMAPS * BLOCK_SIZE != read(dev_fd, inode_map, IMAPS * BLOCK_SIZE))
		die("cannot read inode map");
	if (ZMAPS * BLOCK_SIZE != read(dev_fd, zone_map, ZMAPS * BLOCK_SIZE))
		die("cannot read zone map");
	if (INODE_BUFFER_SIZE != read(dev_fd, inode_buffer, INODE_BUFFER_SIZE))
		die("cannot read inodes");
	if (NORM_FIRSTZONE != FIRSTZONE) {
		printf("warning: firstzone!=norm_firstzone\n");
		errors_uncorrected = 1;
	}
	get_dirsize();
	if (OPT_show) {
		printf("%u inodes\n"
			"%u blocks\n"
			"Firstdatazone=%u (%u)\n"
			"Zonesize=%u\n"
			"Maxsize=%u\n"
			"Filesystem state=%u\n"
			"namelen=%u\n\n",
			INODES,
			ZONES,
			FIRSTZONE, NORM_FIRSTZONE,
			BLOCK_SIZE << ZONESIZE,
			MAXSIZE,
			Super.s_state,
			namelen);
	}
}

static void get_inode_common(unsigned nr, uint16_t i_mode)
{
	total++;
	if (!inode_count[nr]) {
		if (!inode_in_use(nr)) {
			printf("Inode %d is marked as 'unused', but it is used "
					"for file '%s'\n", nr, current_name);
			if (OPT_repair) {
				if (ask("Mark as 'in use'", 1))
					mark_inode(nr);
				else
					errors_uncorrected = 1;
			}
		}
		if (S_ISDIR(i_mode))
			directory++;
		else if (S_ISREG(i_mode))
			regular++;
		else if (S_ISCHR(i_mode))
			chardev++;
		else if (S_ISBLK(i_mode))
			blockdev++;
		else if (S_ISLNK(i_mode))
			symlinks++;
		else if (S_ISSOCK(i_mode));
		else if (S_ISFIFO(i_mode));
		else {
			printf("%s has mode %05o\n", current_name, i_mode);
		}
	} else
		links++;
	if (!++inode_count[nr]) {
		printf("Warning: inode count too big\n");
		inode_count[nr]--;
		errors_uncorrected = 1;
	}
}

static struct minix1_inode *get_inode(unsigned nr)
{
	struct minix1_inode *inode;

	if (!nr || nr > INODES)
		return NULL;
	inode = Inode1 + nr;
	get_inode_common(nr, inode->i_mode);
	return inode;
}

#if ENABLE_FEATURE_MINIX2
static struct minix2_inode *get_inode2(unsigned nr)
{
	struct minix2_inode *inode;

	if (!nr || nr > INODES)
		return NULL;
	inode = Inode2 + nr;
	get_inode_common(nr, inode->i_mode);
	return inode;
}
#endif

static void check_root(void)
{
	struct minix1_inode *inode = Inode1 + MINIX_ROOT_INO;

	if (!inode || !S_ISDIR(inode->i_mode))
		die("root inode isn't a directory");
}

#if ENABLE_FEATURE_MINIX2
static void check_root2(void)
{
	struct minix2_inode *inode = Inode2 + MINIX_ROOT_INO;

	if (!inode || !S_ISDIR(inode->i_mode))
		die("root inode isn't a directory");
}
#else
void check_root2(void);
#endif

static int add_zone_common(int block, smallint *corrected)
{
	if (!block)
		return 0;
	if (zone_count[block]) {
		printf("Already used block is reused in file '%s'. ",
				current_name);
		if (ask("Clear", 1)) {
			block = 0;
			*corrected = 1;
			return -1; /* "please zero out *znr" */
		}
	}
	if (!zone_in_use(block)) {
		printf("Block %d in file '%s' is marked as 'unused'. ",
				block, current_name);
		if (ask("Correct", 1))
			mark_zone(block);
	}
	if (!++zone_count[block])
		zone_count[block]--;
	return block;
}

static int add_zone(uint16_t *znr, smallint *corrected)
{
	int block;

	block = check_zone_nr(znr, corrected);
	block = add_zone_common(block, corrected);
	if (block == -1) {
		*znr = 0;
		block = 0;
	}
	return block;
}

#if ENABLE_FEATURE_MINIX2
static int add_zone2(uint32_t *znr, smallint *corrected)
{
	int block;

	block = check_zone_nr2(znr, corrected);
	block = add_zone_common(block, corrected);
	if (block == -1) {
		*znr = 0;
		block = 0;
	}
	return block;
}
#endif

static void add_zone_ind(uint16_t *znr, smallint *corrected)
{
	int i;
	int block;
	smallint chg_blk = 0;

	block = add_zone(znr, corrected);
	if (!block)
		return;
	read_block(block, add_zone_ind_blk);
	for (i = 0; i < (BLOCK_SIZE >> 1); i++)
		add_zone(i + (uint16_t *) add_zone_ind_blk, &chg_blk);
	if (chg_blk)
		write_block(block, add_zone_ind_blk);
}

#if ENABLE_FEATURE_MINIX2
static void add_zone_ind2(uint32_t *znr, smallint *corrected)
{
	int i;
	int block;
	smallint chg_blk = 0;

	block = add_zone2(znr, corrected);
	if (!block)
		return;
	read_block(block, add_zone_ind_blk);
	for (i = 0; i < BLOCK_SIZE >> 2; i++)
		add_zone2(i + (uint32_t *) add_zone_ind_blk, &chg_blk);
	if (chg_blk)
		write_block(block, add_zone_ind_blk);
}
#endif

static void add_zone_dind(uint16_t *znr, smallint *corrected)
{
	int i;
	int block;
	smallint chg_blk = 0;

	block = add_zone(znr, corrected);
	if (!block)
		return;
	read_block(block, add_zone_dind_blk);
	for (i = 0; i < (BLOCK_SIZE >> 1); i++)
		add_zone_ind(i + (uint16_t *) add_zone_dind_blk, &chg_blk);
	if (chg_blk)
		write_block(block, add_zone_dind_blk);
}

#if ENABLE_FEATURE_MINIX2
static void add_zone_dind2(uint32_t *znr, smallint *corrected)
{
	int i;
	int block;
	smallint chg_blk = 0;

	block = add_zone2(znr, corrected);
	if (!block)
		return;
	read_block(block, add_zone_dind_blk);
	for (i = 0; i < BLOCK_SIZE >> 2; i++)
		add_zone_ind2(i + (uint32_t *) add_zone_dind_blk, &chg_blk);
	if (chg_blk)
		write_block(block, add_zone_dind_blk);
}

static void add_zone_tind2(uint32_t *znr, smallint *corrected)
{
	int i;
	int block;
	smallint chg_blk = 0;

	block = add_zone2(znr, corrected);
	if (!block)
		return;
	read_block(block, add_zone_tind_blk);
	for (i = 0; i < BLOCK_SIZE >> 2; i++)
		add_zone_dind2(i + (uint32_t *) add_zone_tind_blk, &chg_blk);
	if (chg_blk)
		write_block(block, add_zone_tind_blk);
}
#endif

static void check_zones(unsigned i)
{
	struct minix1_inode *inode;

	if (!i || i > INODES)
		return;
	if (inode_count[i] > 1)		/* have we counted this file already? */
		return;
	inode = Inode1 + i;
	if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode) &&
		!S_ISLNK(inode->i_mode)) return;
	for (i = 0; i < 7; i++)
		add_zone(i + inode->i_zone, &changed);
	add_zone_ind(7 + inode->i_zone, &changed);
	add_zone_dind(8 + inode->i_zone, &changed);
}

#if ENABLE_FEATURE_MINIX2
static void check_zones2(unsigned i)
{
	struct minix2_inode *inode;

	if (!i || i > INODES)
		return;
	if (inode_count[i] > 1)		/* have we counted this file already? */
		return;
	inode = Inode2 + i;
	if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode)
		&& !S_ISLNK(inode->i_mode))
		return;
	for (i = 0; i < 7; i++)
		add_zone2(i + inode->i_zone, &changed);
	add_zone_ind2(7 + inode->i_zone, &changed);
	add_zone_dind2(8 + inode->i_zone, &changed);
	add_zone_tind2(9 + inode->i_zone, &changed);
}
#endif

static void check_file(struct minix1_inode *dir, unsigned offset)
{
	struct minix1_inode *inode;
	int ino;
	char *name;
	int block;

	block = map_block(dir, offset / BLOCK_SIZE);
	read_block(block, check_file_blk);
	name = check_file_blk + (offset % BLOCK_SIZE) + 2;
	ino = *(uint16_t *) (name - 2);
	if (ino > INODES) {
		printf("%s contains a bad inode number for file '%.*s'. ",
				current_name, namelen, name);
		if (ask("Remove", 1)) {
			*(uint16_t *) (name - 2) = 0;
			write_block(block, check_file_blk);
		}
		ino = 0;
	}
	push_filename(name);
	inode = get_inode(ino);
	pop_filename();
	if (!offset) {
		if (inode && LONE_CHAR(name, '.'))
			return;
		printf("%s: bad directory: '.' isn't first\n", current_name);
		errors_uncorrected = 1;
	}
	if (offset == dirsize) {
		if (inode && strcmp("..", name) == 0)
			return;
		printf("%s: bad directory: '..' isn't second\n", current_name);
		errors_uncorrected = 1;
	}
	if (!inode)
		return;
	push_filename(name);
	if (OPT_list) {
		if (OPT_verbose)
			printf("%6d %07o %3d ", ino, inode->i_mode, inode->i_nlinks);
		printf("%s%s\n", current_name, S_ISDIR(inode->i_mode) ? ":" : "");
	}
	check_zones(ino);
	if (inode && S_ISDIR(inode->i_mode))
		recursive_check(ino);
	pop_filename();
}

#if ENABLE_FEATURE_MINIX2
static void check_file2(struct minix2_inode *dir, unsigned offset)
{
	struct minix2_inode *inode;
	int ino;
	char *name;
	int block;

	block = map_block2(dir, offset / BLOCK_SIZE);
	read_block(block, check_file_blk);
	name = check_file_blk + (offset % BLOCK_SIZE) + 2;
	ino = *(uint16_t *) (name - 2);
	if (ino > INODES) {
		printf("%s contains a bad inode number for file '%.*s'. ",
				current_name, namelen, name);
		if (ask("Remove", 1)) {
			*(uint16_t *) (name - 2) = 0;
			write_block(block, check_file_blk);
		}
		ino = 0;
	}
	push_filename(name);
	inode = get_inode2(ino);
	pop_filename();
	if (!offset) {
		if (inode && LONE_CHAR(name, '.'))
			return;
		printf("%s: bad directory: '.' isn't first\n", current_name);
		errors_uncorrected = 1;
	}
	if (offset == dirsize) {
		if (inode && strcmp("..", name) == 0)
			return;
		printf("%s: bad directory: '..' isn't second\n", current_name);
		errors_uncorrected = 1;
	}
	if (!inode)
		return;
	push_filename(name);
	if (OPT_list) {
		if (OPT_verbose)
			printf("%6d %07o %3d ", ino, inode->i_mode, inode->i_nlinks);
		printf("%s%s\n", current_name, S_ISDIR(inode->i_mode) ? ":" : "");
	}
	check_zones2(ino);
	if (inode && S_ISDIR(inode->i_mode))
		recursive_check2(ino);
	pop_filename();
}
#endif

static void recursive_check(unsigned ino)
{
	struct minix1_inode *dir;
	unsigned offset;

	dir = Inode1 + ino;
	if (!S_ISDIR(dir->i_mode))
		die("internal error");
	if (dir->i_size < 2 * dirsize) {
		printf("%s: bad directory: size<32", current_name);
		errors_uncorrected = 1;
	}
	for (offset = 0; offset < dir->i_size; offset += dirsize)
		check_file(dir, offset);
}

#if ENABLE_FEATURE_MINIX2
static void recursive_check2(unsigned ino)
{
	struct minix2_inode *dir;
	unsigned offset;

	dir = Inode2 + ino;
	if (!S_ISDIR(dir->i_mode))
		die("internal error");
	if (dir->i_size < 2 * dirsize) {
		printf("%s: bad directory: size<32", current_name);
		errors_uncorrected = 1;
	}
	for (offset = 0; offset < dir->i_size; offset += dirsize)
		check_file2(dir, offset);
}
#endif

static int bad_zone(int i)
{
	char buffer[BLOCK_SIZE];

	xlseek(dev_fd, BLOCK_SIZE * i, SEEK_SET);
	return (BLOCK_SIZE != full_read(dev_fd, buffer, BLOCK_SIZE));
}

static void check_counts(void)
{
	int i;

	for (i = 1; i <= INODES; i++) {
		if (OPT_warn_mode && Inode1[i].i_mode && !inode_in_use(i)) {
			printf("Inode %d has non-zero mode. ", i);
			if (ask("Clear", 1)) {
				Inode1[i].i_mode = 0;
				changed = 1;
			}
		}
		if (!inode_count[i]) {
			if (!inode_in_use(i))
				continue;
			printf("Unused inode %d is marked as 'used' in the bitmap. ", i);
			if (ask("Clear", 1))
				unmark_inode(i);
			continue;
		}
		if (!inode_in_use(i)) {
			printf("Inode %d is used, but marked as 'unused' in the bitmap. ", i);
			if (ask("Set", 1))
				mark_inode(i);
		}
		if (Inode1[i].i_nlinks != inode_count[i]) {
			printf("Inode %d (mode=%07o), i_nlinks=%d, counted=%d. ",
				i, Inode1[i].i_mode, Inode1[i].i_nlinks,
				inode_count[i]);
			if (ask("Set i_nlinks to count", 1)) {
				Inode1[i].i_nlinks = inode_count[i];
				changed = 1;
			}
		}
	}
	for (i = FIRSTZONE; i < ZONES; i++) {
		if ((zone_in_use(i) != 0) == zone_count[i])
			continue;
		if (!zone_count[i]) {
			if (bad_zone(i))
				continue;
			printf("Zone %d is marked 'in use', but no file uses it. ", i);
			if (ask("Unmark", 1))
				unmark_zone(i);
			continue;
		}
		printf("Zone %d: %sin use, counted=%d\n",
			   i, zone_in_use(i) ? "" : "not ", zone_count[i]);
	}
}

#if ENABLE_FEATURE_MINIX2
static void check_counts2(void)
{
	int i;

	for (i = 1; i <= INODES; i++) {
		if (OPT_warn_mode && Inode2[i].i_mode && !inode_in_use(i)) {
			printf("Inode %d has non-zero mode. ", i);
			if (ask("Clear", 1)) {
				Inode2[i].i_mode = 0;
				changed = 1;
			}
		}
		if (!inode_count[i]) {
			if (!inode_in_use(i))
				continue;
			printf("Unused inode %d is marked as 'used' in the bitmap. ", i);
			if (ask("Clear", 1))
				unmark_inode(i);
			continue;
		}
		if (!inode_in_use(i)) {
			printf("Inode %d is used, but marked as 'unused' in the bitmap. ", i);
			if (ask("Set", 1))
				mark_inode(i);
		}
		if (Inode2[i].i_nlinks != inode_count[i]) {
			printf("Inode %d (mode=%07o), i_nlinks=%d, counted=%d. ",
				i, Inode2[i].i_mode, Inode2[i].i_nlinks,
				inode_count[i]);
			if (ask("Set i_nlinks to count", 1)) {
				Inode2[i].i_nlinks = inode_count[i];
				changed = 1;
			}
		}
	}
	for (i = FIRSTZONE; i < ZONES; i++) {
		if ((zone_in_use(i) != 0) == zone_count[i])
			continue;
		if (!zone_count[i]) {
			if (bad_zone(i))
				continue;
			printf("Zone %d is marked 'in use', but no file uses it. ", i);
			if (ask("Unmark", 1))
				unmark_zone(i);
			continue;
		}
		printf("Zone %d: %sin use, counted=%d\n",
			   i, zone_in_use(i) ? "" : "not ", zone_count[i]);
	}
}
#endif

static void check(void)
{
	memset(inode_count, 0, (INODES + 1) * sizeof(*inode_count));
	memset(zone_count, 0, ZONES * sizeof(*zone_count));
	check_zones(MINIX_ROOT_INO);
	recursive_check(MINIX_ROOT_INO);
	check_counts();
}

#if ENABLE_FEATURE_MINIX2
static void check2(void)
{
	memset(inode_count, 0, (INODES + 1) * sizeof(*inode_count));
	memset(zone_count, 0, ZONES * sizeof(*zone_count));
	check_zones2(MINIX_ROOT_INO);
	recursive_check2(MINIX_ROOT_INO);
	check_counts2();
}
#else
void check2(void);
#endif

int fsck_minix_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int fsck_minix_main(int argc UNUSED_PARAM, char **argv)
{
	struct termios tmp;
	int retcode = 0;

	xfunc_error_retval = 8;

	INIT_G();

	opt_complementary = "=1:ar"; /* one argument; -a assumes -r */
	getopt32(argv, OPTION_STR);
	argv += optind;
	device_name = argv[0];

	check_mount();  /* trying to check a mounted filesystem? */
	if (OPT_manual) {
		if (!isatty(0) || !isatty(1))
			die("need terminal for interactive repairs");
	}
	xmove_fd(xopen(device_name, OPT_repair ? O_RDWR : O_RDONLY), dev_fd);

	/*sync(); paranoia? */
	read_superblock();

	/*
	 * Determine whether or not we should continue with the checking.
	 * This is based on the status of the filesystem valid and error
	 * flags and whether or not the -f switch was specified on the
	 * command line.
	 */
	printf("%s: %s\n", applet_name, bb_banner);

	if (!(Super.s_state & MINIX_ERROR_FS)
	 && (Super.s_state & MINIX_VALID_FS) && !OPT_force
	) {
		if (OPT_repair)
			printf("%s is clean, check is skipped\n", device_name);
		return 0;
	} else if (OPT_force)
		printf("Forcing filesystem check on %s\n", device_name);
	else if (OPT_repair)
		printf("Filesystem on %s is dirty, needs checking\n",
			   device_name);

	read_tables();

	if (OPT_manual) {
		tcgetattr(0, &sv_termios);
		tmp = sv_termios;
		tmp.c_lflag &= ~(ICANON | ECHO);
		tcsetattr_stdin_TCSANOW(&tmp);
		termios_set = 1;
	}

	if (version2) {
		check_root2();
		check2();
	} else {
		check_root();
		check();
	}

	if (OPT_verbose) {
		int i, free_cnt;

		for (i = 1, free_cnt = 0; i <= INODES; i++)
			if (!inode_in_use(i))
				free_cnt++;
		printf("\n%6u inodes used (%u%%)\n", (INODES - free_cnt),
			   100 * (INODES - free_cnt) / INODES);
		for (i = FIRSTZONE, free_cnt = 0; i < ZONES; i++)
			if (!zone_in_use(i))
				free_cnt++;
		printf("%6u zones used (%u%%)\n\n"
			   "%6u regular files\n"
			   "%6u directories\n"
			   "%6u character device files\n"
			   "%6u block device files\n"
			   "%6u links\n"
			   "%6u symbolic links\n"
			   "------\n"
			   "%6u files\n",
			   (ZONES - free_cnt), 100 * (ZONES - free_cnt) / ZONES,
			   regular, directory, chardev, blockdev,
			   links - 2 * directory + 1, symlinks,
			   total - 2 * directory + 1);
	}
	if (changed) {
		write_tables();
		printf("FILE SYSTEM HAS BEEN CHANGED\n");
		sync();
	} else if (OPT_repair)
		write_superblock();

	if (OPT_manual)
		tcsetattr_stdin_TCSANOW(&sv_termios);

	if (changed)
		retcode += 3;
	if (errors_uncorrected)
		retcode += 4;
	return retcode;
}