aboutsummaryrefslogtreecommitdiff
path: root/mkfs_minix.c
blob: fafcc230e14bdf44b269492d3d76ceae49c0ba49 (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
/* vi: set sw=4 ts=4: */
/*
 * mkfs.c - make a linux (minix) file-system.
 *
 * (C) 1991 Linus Torvalds. This file may be redistributed as per
 * the Linux copyright.
 */

/*
 * DD.MM.YY
 *
 * 24.11.91  -	Time began. Used the fsck sources to get started.
 *
 * 25.11.91  -	Corrected some bugs. Added support for ".badblocks"
 *		The algorithm for ".badblocks" is a bit weird, but
 *		it should work. Oh, well.
 *
 * 25.01.92  -	Added the -l option for getting the list of bad blocks
 *		out of a named file. (Dave Rivers, rivers@ponds.uucp)
 *
 * 28.02.92  -	Added %-information when using -c.
 *
 * 28.02.93  -	Added support for other namelengths than the original
 *		14 characters so that I can test the new kernel routines..
 *
 * 09.10.93  -	Make exit status conform to that required by fsutil
 *		(Rik Faith, faith@cs.unc.edu)
 *
 * 31.10.93  -	Added inode request feature, for backup floppies: use
 *		32 inodes, for a news partition use more.
 *		(Scott Heavner, sdh@po.cwru.edu)
 *
 * 03.01.94  -	Added support for file system valid flag.
 *		(Dr. Wettstein, greg%wind.uucp@plains.nodak.edu)
 *
 * 30.10.94 - added support for v2 filesystem
 *	      (Andreas Schwab, schwab@issan.informatik.uni-dortmund.de)
 * 
 * 09.11.94  -	Added test to prevent overwrite of mounted fs adapted
 *		from Theodore Ts'o's (tytso@athena.mit.edu) mke2fs
 *		program.  (Daniel Quinlan, quinlan@yggdrasil.com)
 *
 * 03.20.95  -	Clear first 512 bytes of filesystem to make certain that
 *		the filesystem is not misidentified as a MS-DOS FAT filesystem.
 *		(Daniel Quinlan, quinlan@yggdrasil.com)
 *
 * 02.07.96  -  Added small patch from Russell King to make the program a
 *		good deal more portable (janl@math.uio.no)
 *
 * Usage:  mkfs [-c | -l filename ] [-v] [-nXX] [-iXX] device [size-in-blocks]
 *
 *	-c for readablility checking (SLOW!)
 *      -l for getting a list of bad blocks from a file.
 *	-n for namelength (currently the kernel only uses 14 or 30)
 *	-i for number of inodes
 *	-v for v2 filesystem
 *
 * 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 :-). 
 *
 * Modified for BusyBox by Erik Andersen <andersen@debian.org> --
 *	removed getopt based parser and added a hand rolled one.
 */

#include "internal.h"
#include <stdio.h>
#include <time.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <fcntl.h>
#include <ctype.h>
#include <stdlib.h>
#include <termios.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include <mntent.h>


typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned int u32;


#define MINIX_ROOT_INO 1
#define MINIX_LINK_MAX	250
#define MINIX2_LINK_MAX	65530

#define MINIX_I_MAP_SLOTS	8
#define MINIX_Z_MAP_SLOTS	64
#define MINIX_SUPER_MAGIC	0x137F		/* original minix fs */
#define MINIX_SUPER_MAGIC2	0x138F		/* minix fs, 30 char names */
#define MINIX2_SUPER_MAGIC	0x2468		/* minix V2 fs */
#define MINIX2_SUPER_MAGIC2	0x2478		/* minix V2 fs, 30 char names */
#define MINIX_VALID_FS		0x0001		/* Clean fs. */
#define MINIX_ERROR_FS		0x0002		/* fs has errors. */

#define MINIX_INODES_PER_BLOCK ((BLOCK_SIZE)/(sizeof (struct minix_inode)))
#define MINIX2_INODES_PER_BLOCK ((BLOCK_SIZE)/(sizeof (struct minix2_inode)))

#define MINIX_V1		0x0001		/* original minix fs */
#define MINIX_V2		0x0002		/* minix V2 fs */

#define INODE_VERSION(inode)	inode->i_sb->u.minix_sb.s_version

/*
 * This is the original minix inode layout on disk.
 * Note the 8-bit gid and atime and ctime.
 */
struct minix_inode {
	u16 i_mode;
	u16 i_uid;
	u32 i_size;
	u32 i_time;
	u8  i_gid;
	u8  i_nlinks;
	u16 i_zone[9];
};

/*
 * The new minix inode has all the time entries, as well as
 * long block numbers and a third indirect block (7+1+1+1
 * instead of 7+1+1). Also, some previously 8-bit values are
 * now 16-bit. The inode is now 64 bytes instead of 32.
 */
struct minix2_inode {
	u16 i_mode;
	u16 i_nlinks;
	u16 i_uid;
	u16 i_gid;
	u32 i_size;
	u32 i_atime;
	u32 i_mtime;
	u32 i_ctime;
	u32 i_zone[10];
};

/*
 * minix super-block data on disk
 */
struct minix_super_block {
	u16 s_ninodes;
	u16 s_nzones;
	u16 s_imap_blocks;
	u16 s_zmap_blocks;
	u16 s_firstdatazone;
	u16 s_log_zone_size;
	u32 s_max_size;
	u16 s_magic;
	u16 s_state;
	u32 s_zones;
};

struct minix_dir_entry {
	u16 inode;
	char name[0];
};

#define BLOCK_SIZE_BITS 10
#define BLOCK_SIZE (1<<BLOCK_SIZE_BITS)

#define NAME_MAX         255   /* # chars in a file name */

#define MINIX_INODES_PER_BLOCK ((BLOCK_SIZE)/(sizeof (struct minix_inode)))

#define MINIX_VALID_FS               0x0001          /* Clean fs. */
#define MINIX_ERROR_FS               0x0002          /* fs has errors. */

#define MINIX_SUPER_MAGIC    0x137F          /* original minix fs */
#define MINIX_SUPER_MAGIC2   0x138F          /* minix fs, 30 char names */

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


#ifndef __linux__
#define volatile
#endif

#define MINIX_ROOT_INO 1
#define MINIX_BAD_INO 2

#define TEST_BUFFER_BLOCKS 16
#define MAX_GOOD_BLOCKS 512

#define UPPER(size,n) (((size)+((n)-1))/(n))
#define INODE_SIZE (sizeof(struct minix_inode))
#ifdef BB_FEATURE_MINIX2
#define INODE_SIZE2 (sizeof(struct minix2_inode))
#define INODE_BLOCKS UPPER(INODES, (version2 ? MINIX2_INODES_PER_BLOCK \
				    : MINIX_INODES_PER_BLOCK))
#else
#define INODE_BLOCKS UPPER(INODES, (MINIX_INODES_PER_BLOCK))
#endif
#define INODE_BUFFER_SIZE (INODE_BLOCKS * BLOCK_SIZE)

#define BITS_PER_BLOCK (BLOCK_SIZE<<3)

static char *device_name = NULL;
static int DEV = -1;
static long BLOCKS = 0;
static int check = 0;
static int badblocks = 0;
static int namelen = 30;		/* default (changed to 30, per Linus's

								   suggestion, Sun Nov 21 08:05:07 1993) */
static int dirsize = 32;
static int magic = MINIX_SUPER_MAGIC2;
static int version2 = 0;

static char root_block[BLOCK_SIZE] = "\0";

static char *inode_buffer = NULL;

#define Inode (((struct minix_inode *) inode_buffer)-1)
#ifdef BB_FEATURE_MINIX2
#define Inode2 (((struct minix2_inode *) inode_buffer)-1)
#endif
static char super_block_buffer[BLOCK_SIZE];
static char boot_block_buffer[512];

#define Super (*(struct minix_super_block *)super_block_buffer)
#define INODES ((unsigned long)Super.s_ninodes)
#ifdef BB_FEATURE_MINIX2
#define ZONES ((unsigned long)(version2 ? Super.s_zones : Super.s_nzones))
#else
#define ZONES ((unsigned long)(Super.s_nzones))
#endif
#define IMAPS ((unsigned long)Super.s_imap_blocks)
#define ZMAPS ((unsigned long)Super.s_zmap_blocks)
#define FIRSTZONE ((unsigned long)Super.s_firstdatazone)
#define ZONESIZE ((unsigned long)Super.s_log_zone_size)
#define MAXSIZE ((unsigned long)Super.s_max_size)
#define MAGIC (Super.s_magic)
#define NORM_FIRSTZONE (2+IMAPS+ZMAPS+INODE_BLOCKS)

static char *inode_map;
static char *zone_map;

static unsigned short good_blocks_table[MAX_GOOD_BLOCKS];
static int used_good_blocks = 0;
static unsigned long req_nr_inodes = 0;

static inline int bit(char * a,unsigned int i)
{
	  return (a[i >> 3] & (1<<(i & 7))) != 0;
}
#define inode_in_use(x) (bit(inode_map,(x)))
#define zone_in_use(x) (bit(zone_map,(x)-FIRSTZONE+1))

#define mark_inode(x) (setbit(inode_map,(x)))
#define unmark_inode(x) (clrbit(inode_map,(x)))

#define mark_zone(x) (setbit(zone_map,(x)-FIRSTZONE+1))
#define unmark_zone(x) (clrbit(zone_map,(x)-FIRSTZONE+1))

/*
 * Volatile to let gcc know that this doesn't return. When trying
 * to compile this under minix, volatile gives a warning, as
 * exit() isn't defined as volatile under minix.
 */
static volatile void die(char *str)
{
	errorMsg("%s\n", str);
	exit(8);
}

static volatile void show_usage() __attribute__ ((noreturn));
static volatile void show_usage()
{
	usage(mkfs_minix_usage);
}

/*
 * Check to make certain that our new filesystem won't be created on
 * an already mounted partition.  Code adapted from mke2fs, Copyright
 * (C) 1994 Theodore Ts'o.  Also licensed under GPL.
 */
static void check_mount(void)
{
	FILE *f;
	struct mntent *mnt;

	if ((f = setmntent(MOUNTED, "r")) == NULL)
		return;
	while ((mnt = getmntent(f)) != NULL)
		if (strcmp(device_name, mnt->mnt_fsname) == 0)
			break;
	endmntent(f);
	if (!mnt)
		return;

	die("%s is mounted; will not make a filesystem here!");
}

static long valid_offset(int fd, int offset)
{
	char ch;

	if (lseek(fd, offset, 0) < 0)
		return 0;
	if (read(fd, &ch, 1) < 1)
		return 0;
	return 1;
}

static int count_blocks(int fd)
{
	int high, low;

	low = 0;
	for (high = 1; valid_offset(fd, high); high *= 2)
		low = high;
	while (low < high - 1) {
		const int mid = (low + high) / 2;

		if (valid_offset(fd, mid))
			low = mid;
		else
			high = mid;
	}
	valid_offset(fd, 0);
	return (low + 1);
}

static int get_size(const char *file)
{
	int fd;
	long size;

	fd = open(file, O_RDWR);
	if (fd < 0) {
		perror(file);
		exit(1);
	}
	if (ioctl(fd, BLKGETSIZE, &size) >= 0) {
		close(fd);
		return (size * 512);
	}

	size = count_blocks(fd);
	close(fd);
	return size;
}

static void write_tables(void)
{
	/* Mark the super block valid. */
	Super.s_state |= MINIX_VALID_FS;
	Super.s_state &= ~MINIX_ERROR_FS;

	if (lseek(DEV, 0, SEEK_SET))
		die("seek to boot block failed in write_tables");
	if (512 != write(DEV, boot_block_buffer, 512))
		die("unable to clear boot sector");
	if (BLOCK_SIZE != lseek(DEV, BLOCK_SIZE, SEEK_SET))
		die("seek failed in write_tables");
	if (BLOCK_SIZE != write(DEV, super_block_buffer, BLOCK_SIZE))
		die("unable to write super-block");
	if (IMAPS * BLOCK_SIZE != write(DEV, inode_map, IMAPS * BLOCK_SIZE))
		die("unable to write inode map");
	if (ZMAPS * BLOCK_SIZE != write(DEV, zone_map, ZMAPS * BLOCK_SIZE))
		die("unable to write zone map");
	if (INODE_BUFFER_SIZE != write(DEV, inode_buffer, INODE_BUFFER_SIZE))
		die("unable to write inodes");

}

static void write_block(int blk, char *buffer)
{
	if (blk * BLOCK_SIZE != lseek(DEV, blk * BLOCK_SIZE, SEEK_SET))
		die("seek failed in write_block");
	if (BLOCK_SIZE != write(DEV, buffer, BLOCK_SIZE))
		die("write failed in write_block");
}

static int get_free_block(void)
{
	int blk;

	if (used_good_blocks + 1 >= MAX_GOOD_BLOCKS)
		die("too many bad blocks");
	if (used_good_blocks)
		blk = good_blocks_table[used_good_blocks - 1] + 1;
	else
		blk = FIRSTZONE;
	while (blk < ZONES && zone_in_use(blk))
		blk++;
	if (blk >= ZONES)
		die("not enough good blocks");
	good_blocks_table[used_good_blocks] = blk;
	used_good_blocks++;
	return blk;
}

static void mark_good_blocks(void)
{
	int blk;

	for (blk = 0; blk < used_good_blocks; blk++)
		mark_zone(good_blocks_table[blk]);
}

inline int next(int zone)
{
	if (!zone)
		zone = FIRSTZONE - 1;
	while (++zone < ZONES)
		if (zone_in_use(zone))
			return zone;
	return 0;
}

static void make_bad_inode(void)
{
	struct minix_inode *inode = &Inode[MINIX_BAD_INO];
	int i, j, zone;
	int ind = 0, dind = 0;
	unsigned short ind_block[BLOCK_SIZE >> 1];
	unsigned short dind_block[BLOCK_SIZE >> 1];

#define NEXT_BAD (zone = next(zone))

	if (!badblocks)
		return;
	mark_inode(MINIX_BAD_INO);
	inode->i_nlinks = 1;
	inode->i_time = time(NULL);
	inode->i_mode = S_IFREG + 0000;
	inode->i_size = badblocks * BLOCK_SIZE;
	zone = next(0);
	for (i = 0; i < 7; i++) {
		inode->i_zone[i] = zone;
		if (!NEXT_BAD)
			goto end_bad;
	}
	inode->i_zone[7] = ind = get_free_block();
	memset(ind_block, 0, BLOCK_SIZE);
	for (i = 0; i < 512; i++) {
		ind_block[i] = zone;
		if (!NEXT_BAD)
			goto end_bad;
	}
	inode->i_zone[8] = dind = get_free_block();
	memset(dind_block, 0, BLOCK_SIZE);
	for (i = 0; i < 512; i++) {
		write_block(ind, (char *) ind_block);
		dind_block[i] = ind = get_free_block();
		memset(ind_block, 0, BLOCK_SIZE);
		for (j = 0; j < 512; j++) {
			ind_block[j] = zone;
			if (!NEXT_BAD)
				goto end_bad;
		}
	}
	die("too many bad blocks");
  end_bad:
	if (ind)
		write_block(ind, (char *) ind_block);
	if (dind)
		write_block(dind, (char *) dind_block);
}

#ifdef BB_FEATURE_MINIX2
static void make_bad_inode2(void)
{
	struct minix2_inode *inode = &Inode2[MINIX_BAD_INO];
	int i, j, zone;
	int ind = 0, dind = 0;
	unsigned long ind_block[BLOCK_SIZE >> 2];
	unsigned long dind_block[BLOCK_SIZE >> 2];

	if (!badblocks)
		return;
	mark_inode(MINIX_BAD_INO);
	inode->i_nlinks = 1;
	inode->i_atime = inode->i_mtime = inode->i_ctime = time(NULL);
	inode->i_mode = S_IFREG + 0000;
	inode->i_size = badblocks * BLOCK_SIZE;
	zone = next(0);
	for (i = 0; i < 7; i++) {
		inode->i_zone[i] = zone;
		if (!NEXT_BAD)
			goto end_bad;
	}
	inode->i_zone[7] = ind = get_free_block();
	memset(ind_block, 0, BLOCK_SIZE);
	for (i = 0; i < 256; i++) {
		ind_block[i] = zone;
		if (!NEXT_BAD)
			goto end_bad;
	}
	inode->i_zone[8] = dind = get_free_block();
	memset(dind_block, 0, BLOCK_SIZE);
	for (i = 0; i < 256; i++) {
		write_block(ind, (char *) ind_block);
		dind_block[i] = ind = get_free_block();
		memset(ind_block, 0, BLOCK_SIZE);
		for (j = 0; j < 256; j++) {
			ind_block[j] = zone;
			if (!NEXT_BAD)
				goto end_bad;
		}
	}
	/* Could make triple indirect block here */
	die("too many bad blocks");
  end_bad:
	if (ind)
		write_block(ind, (char *) ind_block);
	if (dind)
		write_block(dind, (char *) dind_block);
}
#endif

static void make_root_inode(void)
{
	struct minix_inode *inode = &Inode[MINIX_ROOT_INO];

	mark_inode(MINIX_ROOT_INO);
	inode->i_zone[0] = get_free_block();
	inode->i_nlinks = 2;
	inode->i_time = time(NULL);
	if (badblocks)
		inode->i_size = 3 * dirsize;
	else {
		root_block[2 * dirsize] = '\0';
		root_block[2 * dirsize + 1] = '\0';
		inode->i_size = 2 * dirsize;
	}
	inode->i_mode = S_IFDIR + 0755;
	inode->i_uid = getuid();
	if (inode->i_uid)
		inode->i_gid = getgid();
	write_block(inode->i_zone[0], root_block);
}

#ifdef BB_FEATURE_MINIX2
static void make_root_inode2(void)
{
	struct minix2_inode *inode = &Inode2[MINIX_ROOT_INO];

	mark_inode(MINIX_ROOT_INO);
	inode->i_zone[0] = get_free_block();
	inode->i_nlinks = 2;
	inode->i_atime = inode->i_mtime = inode->i_ctime = time(NULL);
	if (badblocks)
		inode->i_size = 3 * dirsize;
	else {
		root_block[2 * dirsize] = '\0';
		root_block[2 * dirsize + 1] = '\0';
		inode->i_size = 2 * dirsize;
	}
	inode->i_mode = S_IFDIR + 0755;
	inode->i_uid = getuid();
	if (inode->i_uid)
		inode->i_gid = getgid();
	write_block(inode->i_zone[0], root_block);
}
#endif

static void setup_tables(void)
{
	int i;
	unsigned long inodes;

	memset(super_block_buffer, 0, BLOCK_SIZE);
	memset(boot_block_buffer, 0, 512);
	MAGIC = magic;
	ZONESIZE = 0;
	MAXSIZE = version2 ? 0x7fffffff : (7 + 512 + 512 * 512) * 1024;
	ZONES = BLOCKS;
/* some magic nrs: 1 inode / 3 blocks */
	if (req_nr_inodes == 0)
		inodes = BLOCKS / 3;
	else
		inodes = req_nr_inodes;
	/* Round up inode count to fill block size */
#ifdef BB_FEATURE_MINIX2
	if (version2)
		inodes = ((inodes + MINIX2_INODES_PER_BLOCK - 1) &
				  ~(MINIX2_INODES_PER_BLOCK - 1));
	else
#endif
		inodes = ((inodes + MINIX_INODES_PER_BLOCK - 1) &
				  ~(MINIX_INODES_PER_BLOCK - 1));
	if (inodes > 65535)
		inodes = 65535;
	INODES = inodes;
	IMAPS = UPPER(INODES + 1, BITS_PER_BLOCK);
	ZMAPS = 0;
	i = 0;
	while (ZMAPS !=
		   UPPER(BLOCKS - (2 + IMAPS + ZMAPS + INODE_BLOCKS) + 1,
				 BITS_PER_BLOCK) && i < 1000) {
		ZMAPS =
			UPPER(BLOCKS - (2 + IMAPS + ZMAPS + INODE_BLOCKS) + 1,
				  BITS_PER_BLOCK);
		i++;
	}
	/* Real bad hack but overwise mkfs.minix can be thrown
	 * in infinite loop...
	 * try:
	 * dd if=/dev/zero of=test.fs count=10 bs=1024
	 * /sbin/mkfs.minix -i 200 test.fs
	 * */
	if (i >= 999) {
		die("unable to allocate buffers for maps");
	}
	FIRSTZONE = NORM_FIRSTZONE;
	inode_map = xmalloc(IMAPS * BLOCK_SIZE);
	zone_map = xmalloc(ZMAPS * BLOCK_SIZE);
	memset(inode_map, 0xff, IMAPS * BLOCK_SIZE);
	memset(zone_map, 0xff, ZMAPS * BLOCK_SIZE);
	for (i = FIRSTZONE; i < ZONES; i++)
		unmark_zone(i);
	for (i = MINIX_ROOT_INO; i <= INODES; i++)
		unmark_inode(i);
	inode_buffer = xmalloc(INODE_BUFFER_SIZE);
	memset(inode_buffer, 0, INODE_BUFFER_SIZE);
	printf("%ld inodes\n", INODES);
	printf("%ld blocks\n", ZONES);
	printf("Firstdatazone=%ld (%ld)\n", FIRSTZONE, NORM_FIRSTZONE);
	printf("Zonesize=%d\n", BLOCK_SIZE << ZONESIZE);
	printf("Maxsize=%ld\n\n", MAXSIZE);
}

/*
 * Perform a test of a block; return the number of
 * blocks readable/writeable.
 */
long do_check(char *buffer, int try, unsigned int current_block)
{
	long got;

	/* Seek to the correct loc. */
	if (lseek(DEV, current_block * BLOCK_SIZE, SEEK_SET) !=
		current_block * BLOCK_SIZE) {
		die("seek failed during testing of blocks");
	}


	/* Try the read */
	got = read(DEV, buffer, try * BLOCK_SIZE);
	if (got < 0)
		got = 0;
	if (got & (BLOCK_SIZE - 1)) {
		printf("Weird values in do_check: probably bugs\n");
	}
	got /= BLOCK_SIZE;
	return got;
}

static unsigned int currently_testing = 0;

static void alarm_intr(int alnum)
{
	if (currently_testing >= ZONES)
		return;
	signal(SIGALRM, alarm_intr);
	alarm(5);
	if (!currently_testing)
		return;
	printf("%d ...", currently_testing);
	fflush(stdout);
}

static void check_blocks(void)
{
	int try, got;
	static char buffer[BLOCK_SIZE * TEST_BUFFER_BLOCKS];

	currently_testing = 0;
	signal(SIGALRM, alarm_intr);
	alarm(5);
	while (currently_testing < ZONES) {
		if (lseek(DEV, currently_testing * BLOCK_SIZE, SEEK_SET) !=
			currently_testing * BLOCK_SIZE)
			die("seek failed in check_blocks");
		try = TEST_BUFFER_BLOCKS;
		if (currently_testing + try > ZONES)
			try = ZONES - currently_testing;
		got = do_check(buffer, try, currently_testing);
		currently_testing += got;
		if (got == try)
			continue;
		if (currently_testing < FIRSTZONE)
			die("bad blocks before data-area: cannot make fs");
		mark_zone(currently_testing);
		badblocks++;
		currently_testing++;
	}
	if (badblocks > 1)
		printf("%d bad blocks\n", badblocks);
	else if (badblocks == 1)
		printf("one bad block\n");
}

static void get_list_blocks(filename)
char *filename;

{
	FILE *listfile;
	unsigned long blockno;

	listfile = fopen(filename, "r");
	if (listfile == (FILE *) NULL) {
		die("can't open file of bad blocks");
	}
	while (!feof(listfile)) {
		fscanf(listfile, "%ld\n", &blockno);
		mark_zone(blockno);
		badblocks++;
	}
	if (badblocks > 1)
		printf("%d bad blocks\n", badblocks);
	else if (badblocks == 1)
		printf("one bad block\n");
}

extern int mkfs_minix_main(int argc, char **argv)
{
	int i=1;
	char *tmp;
	struct stat statbuf;
	char *listfile = NULL;
	int stopIt=FALSE;

	if (INODE_SIZE * MINIX_INODES_PER_BLOCK != BLOCK_SIZE)
		die("bad inode size");
#ifdef BB_FEATURE_MINIX2
	if (INODE_SIZE2 * MINIX2_INODES_PER_BLOCK != BLOCK_SIZE)
		die("bad inode size");
#endif
	
	/* Parse options */
	argv++;
	while (--argc >= 0 && *argv && **argv) {
		if (**argv == '-') {
			stopIt=FALSE;
			while (i > 0 && *++(*argv) && stopIt==FALSE) {
				switch (**argv) {
					case 'c':
						check = 1;
						break;
					case 'i':
						{
							char *cp=NULL;
							if (*(*argv+1) != 0) {
								cp = ++(*argv);
							} else {
								if (--argc == 0) {
									goto goodbye;
								}
								cp = *(++argv);
							}
							req_nr_inodes = strtoul(cp, &tmp, 0);
							if (*tmp)
								show_usage();
							stopIt=TRUE;
							break;
						}
					case 'l':
						if (--argc == 0) {
							goto goodbye;
						}
						listfile = *(++argv);
						break;
					case 'n':
						{
							char *cp=NULL;

							if (*(*argv+1) != 0) {
								cp = ++(*argv);
							} else {
								if (--argc == 0) {
									goto goodbye;
								}
								cp = *(++argv);
							}
							i = strtoul(cp, &tmp, 0);
							if (*tmp)
								show_usage();
							if (i == 14)
								magic = MINIX_SUPER_MAGIC;
							else if (i == 30)
								magic = MINIX_SUPER_MAGIC2;
							else 
								show_usage();
							namelen = i;
							dirsize = i + 2;
							stopIt=TRUE;
							break;
						}
					case 'v':
#ifdef BB_FEATURE_MINIX2
						version2 = 1;
#else
						errorMsg("%s: not compiled with minix v2 support\n",
								device_name);
						exit(-1);
#endif
						break;
					case '-':
					case 'h':
					default:
goodbye:
						show_usage();
				}
			}
		} else {
			if (device_name == NULL)
				device_name = *argv;
			else if (BLOCKS == 0)
				BLOCKS = strtol(*argv, &tmp, 0);
			else {
				goto goodbye;
			}
		}
		argv++;
	}

	if (device_name && !BLOCKS)
		BLOCKS = get_size(device_name) / 1024;
	if (!device_name || BLOCKS < 10) {
		show_usage();
	}
#ifdef BB_FEATURE_MINIX2
	if (version2) {
		if (namelen == 14)
			magic = MINIX2_SUPER_MAGIC;
		else
			magic = MINIX2_SUPER_MAGIC2;
	} else
#endif
	if (BLOCKS > 65535)
		BLOCKS = 65535;
	check_mount();				/* is it already mounted? */
	tmp = root_block;
	*(short *) tmp = 1;
	strcpy(tmp + 2, ".");
	tmp += dirsize;
	*(short *) tmp = 1;
	strcpy(tmp + 2, "..");
	tmp += dirsize;
	*(short *) tmp = 2;
	strcpy(tmp + 2, ".badblocks");
	DEV = open(device_name, O_RDWR);
	if (DEV < 0)
		die("unable to open %s");
	if (fstat(DEV, &statbuf) < 0)
		die("unable to stat %s");
	if (!S_ISBLK(statbuf.st_mode))
		check = 0;
	else if (statbuf.st_rdev == 0x0300 || statbuf.st_rdev == 0x0340)
		die("will not try to make filesystem on '%s'");
	setup_tables();
	if (check)
		check_blocks();
	else if (listfile)
		get_list_blocks(listfile);
#ifdef BB_FEATURE_MINIX2
	if (version2) {
		make_root_inode2();
		make_bad_inode2();
	} else
#endif
	{
		make_root_inode();
		make_bad_inode();
	}
	mark_good_blocks();
	write_tables();
	return( 0);

}