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[minix3.git] / minix / usr.sbin / mkfs.mfs / mkfs.c
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1 /* mkfs - make the MINIX filesystem Authors: Tanenbaum et al. */
3 /* Authors: Andy Tanenbaum, Paul Ogilvie, Frans Meulenbroeks, Bruce Evans */
5 #if HAVE_NBTOOL_CONFIG_H
6 #include "nbtool_config.h"
7 #endif
9 #include <sys/cdefs.h>
10 #include <sys/types.h>
11 #include <sys/stat.h>
13 #if defined(__minix)
14 #include <minix/minlib.h>
15 #include <minix/partition.h>
16 #include <sys/ioctl.h>
17 #endif
19 #include <assert.h>
20 #include <err.h>
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <limits.h>
24 #include <stdarg.h>
25 #include <stdint.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <time.h>
30 #include <unistd.h>
32 /* Definition of the file system layout: */
33 #include "const.h"
34 #include "type.h"
35 #include "mfsdir.h"
36 #include "super.h"
38 #define INODE_MAP START_BLOCK
39 /* inode zone indexes pointing to single and double indirect zones */
40 #define S_INDIRECT_IDX (NR_DZONES)
41 #define D_INDIRECT_IDX (NR_DZONES+1)
44 #define MAX_TOKENS 10
45 #define LINE_LEN 300
47 /* some Minix specific types that do not conflict with Posix */
48 #ifndef block_t
49 typedef uint32_t block_t; /* block number */
50 #endif
51 #ifndef zone_t
52 typedef uint32_t zone_t; /* zone number */
53 #endif
54 #ifndef bit_t
55 typedef uint32_t bit_t; /* bit number in a bit map */
56 #endif
57 #ifndef bitchunk_t
58 typedef uint32_t bitchunk_t; /* collection of bits in a bitmap */
59 #endif
61 struct fs_size {
62 ino_t inocount; /* amount of inodes */
63 zone_t zonecount; /* amount of zones */
64 block_t blockcount; /* amount of blocks */
67 extern char *optarg;
68 extern int optind;
70 block_t nrblocks;
71 int zone_per_block, zone_shift = 0;
72 zone_t next_zone, zoff, nr_indirzones;
73 int inodes_per_block, indir_per_block, indir_per_zone;
74 unsigned int zone_size;
75 ino_t nrinodes, inode_offset, next_inode;
76 int lct = 0, fd, print = 0;
77 int simple = 0, dflag = 0, verbose = 0;
78 int donttest; /* skip test if it fits on medium */
79 char *progname;
80 uint64_t fs_offset_bytes, fs_offset_blocks, written_fs_size = 0;
82 time_t current_time;
83 char *zero;
84 unsigned char *umap_array; /* bit map tells if block read yet */
85 size_t umap_array_elements;
86 block_t zone_map; /* where is zone map? (depends on # inodes) */
87 #ifndef MFS_STATIC_BLOCK_SIZE
88 size_t block_size;
89 #else
90 #define block_size MFS_STATIC_BLOCK_SIZE
91 #endif
93 FILE *proto;
95 int main(int argc, char **argv);
96 void detect_fs_size(struct fs_size * fssize);
97 void sizeup_dir(struct fs_size * fssize);
98 block_t sizeup(char *device);
99 static int bitmapsize(bit_t nr_bits, size_t blk_size);
100 void super(zone_t zones, ino_t inodes);
101 void rootdir(ino_t inode);
102 void enter_symlink(ino_t inode, char *link);
103 int dir_try_enter(zone_t z, ino_t child, char const *name);
104 void eat_dir(ino_t parent);
105 void eat_file(ino_t inode, int f);
106 void enter_dir(ino_t parent, char const *name, ino_t child);
107 void add_zone(ino_t n, zone_t z, size_t bytes, time_t cur_time);
108 void incr_link(ino_t n);
109 void incr_size(ino_t n, size_t count);
110 static ino_t alloc_inode(int mode, int usrid, int grpid);
111 static zone_t alloc_zone(void);
112 void insert_bit(block_t block, bit_t bit);
113 int mode_con(char *p);
114 void get_line(char line[LINE_LEN], char *parse[MAX_TOKENS]);
115 void check_mtab(const char *devname);
116 time_t file_time(int f);
117 __dead void pexit(char const *s, ...) __printflike(1,2);
118 void *alloc_block(void);
119 void print_fs(void);
120 int read_and_set(block_t n);
121 void special(char *string, int insertmode);
122 __dead void usage(void);
123 void get_block(block_t n, void *buf);
124 void get_super_block(void *buf);
125 void put_block(block_t n, void *buf);
126 static uint64_t mkfs_seek(uint64_t pos, int whence);
127 static ssize_t mkfs_write(void * buf, size_t count);
129 /*================================================================
130 * mkfs - make filesystem
131 *===============================================================*/
133 main(int argc, char *argv[])
135 int nread, mode, usrid, grpid, ch, extra_space_percent, Tflag = 0;
136 block_t blocks, maxblocks, bblocks;
137 ino_t inodes, root_inum;
138 char *token[MAX_TOKENS], line[LINE_LEN], *sfx;
139 struct fs_size fssize;
140 int insertmode = 0;
142 progname = argv[0];
144 /* Process switches. */
145 blocks = 0;
146 inodes = 0;
147 bblocks = 0;
148 #ifndef MFS_STATIC_BLOCK_SIZE
149 block_size = 0;
150 #endif
151 zone_shift = 0;
152 extra_space_percent = 0;
153 while ((ch = getopt(argc, argv, "B:b:di:ltvx:z:I:T:")) != EOF)
154 switch (ch) {
155 #ifndef MFS_STATIC_BLOCK_SIZE
156 case 'B':
157 block_size = strtoul(optarg, &sfx, 0);
158 switch(*sfx) {
159 case 'b': case 'B': /* bytes; NetBSD-compatible */
160 case '\0': break;
161 case 'K':
162 case 'k': block_size*=1024; break;
163 case 's': block_size*=SECTOR_SIZE; break;
164 default: usage();
166 break;
167 #else
168 case 'B':
169 if (block_size != strtoul(optarg, (char **) NULL, 0))
170 errx(4, "block size must be exactly %d bytes",
171 MFS_STATIC_BLOCK_SIZE);
172 break;
173 (void)sfx; /* shut up warnings about unused variable...*/
174 #endif
175 case 'I':
176 fs_offset_bytes = strtoul(optarg, (char **) NULL, 0);
177 insertmode = 1;
178 break;
179 case 'b':
180 blocks = bblocks = strtoul(optarg, (char **) NULL, 0);
181 break;
182 case 'T':
183 Tflag = 1;
184 current_time = strtoul(optarg, (char **) NULL, 0);
185 break;
186 case 'd':
187 dflag = 1;
188 break;
189 case 'i':
190 inodes = strtoul(optarg, (char **) NULL, 0);
191 break;
192 case 'l': print = 1; break;
193 case 't': donttest = 1; break;
194 case 'v': ++verbose; break;
195 case 'x': extra_space_percent = atoi(optarg); break;
196 case 'z': zone_shift = atoi(optarg); break;
197 default: usage();
200 if (argc == optind) usage();
202 /* Get the current time, set it to the mod time of the binary of
203 * mkfs itself when the -d flag is used. The 'current' time is put into
204 * the i_mtimes of all the files. This -d feature is useful when
205 * producing a set of file systems, and one wants all the times to be
206 * identical. First you set the time of the mkfs binary to what you
207 * want, then go.
209 if(Tflag) {
210 if(dflag)
211 errx(1, "-T and -d both specify a time and so are mutually exclusive");
212 } else if(dflag) {
213 struct stat statbuf;
214 if (stat(progname, &statbuf)) {
215 err(1, "stat of itself");
217 current_time = statbuf.st_mtime;
218 } else {
219 current_time = time((time_t *) 0); /* time mkfs is being run */
222 /* Percentage of extra size must be nonnegative.
223 * It can legitimately be bigger than 100 but has to make some sort of sense.
225 if(extra_space_percent < 0 || extra_space_percent > 2000) usage();
227 #ifdef DEFAULT_BLOCK_SIZE
228 if(!block_size) block_size = DEFAULT_BLOCK_SIZE;
229 #endif
230 if (block_size % SECTOR_SIZE)
231 errx(4, "block size must be multiple of sector (%d bytes)", SECTOR_SIZE);
232 #ifdef MIN_BLOCK_SIZE
233 if (block_size < MIN_BLOCK_SIZE)
234 errx(4, "block size must be at least %d bytes", MIN_BLOCK_SIZE);
235 #endif
236 #ifdef MAX_BLOCK_SIZE
237 if (block_size > MAX_BLOCK_SIZE)
238 errx(4, "block size must be at most %d bytes", MAX_BLOCK_SIZE);
239 #endif
240 if(block_size%INODE_SIZE)
241 errx(4, "block size must be a multiple of inode size (%d bytes)", INODE_SIZE);
243 if(zone_shift < 0 || zone_shift > 14)
244 errx(4, "zone_shift must be a small non-negative integer");
245 zone_per_block = 1 << zone_shift; /* nr of blocks per zone */
247 inodes_per_block = INODES_PER_BLOCK(block_size);
248 indir_per_block = INDIRECTS(block_size);
249 indir_per_zone = INDIRECTS(block_size) << zone_shift;
250 /* number of file zones we can address directly and with a single indirect*/
251 nr_indirzones = NR_DZONES + indir_per_zone;
252 zone_size = block_size << zone_shift;
253 /* Checks for an overflow: only with very big block size */
254 if (zone_size <= 0)
255 errx(4, "Zones are too big for this program; smaller -B or -z, please!");
257 /* now that the block size is known, do buffer allocations where
258 * possible.
260 zero = alloc_block();
262 fs_offset_blocks = roundup(fs_offset_bytes, block_size) / block_size;
264 /* Determine the size of the device if not specified as -b or proto. */
265 maxblocks = sizeup(argv[optind]);
266 if (bblocks != 0 && bblocks + fs_offset_blocks > maxblocks && !insertmode) {
267 errx(4, "Given size -b %d exceeds device capacity(%d)\n", bblocks, maxblocks);
270 if (argc - optind == 1 && bblocks == 0) {
271 blocks = maxblocks;
272 /* blocks == 0 is checked later, but leads to a funny way of
273 * reporting a 0-sized device (displays usage).
275 if(blocks < 1) {
276 errx(1, "zero size device.");
280 /* The remaining args must be 'special proto', or just 'special' if the
281 * no. of blocks has already been specified.
283 if (argc - optind != 2 && (argc - optind != 1 || blocks == 0)) usage();
285 if (maxblocks && blocks > maxblocks && !insertmode) {
286 errx(1, "%s: number of blocks too large for device.", argv[optind]);
289 /* Check special. */
290 check_mtab(argv[optind]);
292 /* Check and start processing proto. */
293 optarg = argv[++optind];
294 if (optind < argc && (proto = fopen(optarg, "r")) != NULL) {
295 /* Prototype file is readable. */
296 lct = 1;
297 get_line(line, token); /* skip boot block info */
299 /* Read the line with the block and inode counts. */
300 get_line(line, token);
301 if (bblocks == 0){
302 blocks = strtol(token[0], (char **) NULL, 10);
303 } else {
304 if(bblocks < strtol(token[0], (char **) NULL, 10)) {
305 errx(1, "%s: number of blocks given as parameter(%d)"
306 " is too small for given proto file(%ld).",
307 argv[optind], bblocks,
308 strtol(token[0], (char **) NULL, 10));
311 inodes = strtol(token[1], (char **) NULL, 10);
313 /* Process mode line for root directory. */
314 get_line(line, token);
315 mode = mode_con(token[0]);
316 usrid = atoi(token[1]);
317 grpid = atoi(token[2]);
319 if(blocks <= 0 && inodes <= 0){
320 detect_fs_size(&fssize);
321 blocks = fssize.blockcount;
322 inodes = fssize.inocount;
323 blocks += blocks*extra_space_percent/100;
324 inodes += inodes*extra_space_percent/100;
325 /* XXX is it OK to write on stdout? Use warn() instead? Also consider using verbose */
326 fprintf(stderr, "dynamically sized filesystem: %u blocks, %u inodes\n",
327 (unsigned int) blocks, (unsigned int) inodes);
329 } else {
330 lct = 0;
331 if (optind < argc) {
332 /* Maybe the prototype file is just a size. Check. */
333 blocks = strtoul(optarg, (char **) NULL, 0);
334 if (blocks == 0) errx(2, "Can't open prototype file");
337 /* Make simple file system of the given size, using defaults. */
338 mode = 040777;
339 usrid = 0;
340 grpid = 0;
341 simple = 1;
344 if (inodes == 0) {
345 long long kb = ((unsigned long long)blocks*block_size) / 1024;
347 inodes = kb / 2;
348 if (kb >= 100000) inodes = kb / 4;
349 if (kb >= 1000000) inodes = kb / 6;
350 if (kb >= 10000000) inodes = kb / 8;
351 if (kb >= 100000000) inodes = kb / 10;
352 if (kb >= 1000000000) inodes = kb / 12;
353 /* XXX check overflow: with very large number of blocks, this results in insanely large number of inodes */
354 /* XXX check underflow (if/when ino_t is signed), else the message below will look strange */
356 /* round up to fill inode block */
357 inodes += inodes_per_block - 1;
358 inodes = inodes / inodes_per_block * inodes_per_block;
361 if (blocks < 5) errx(1, "Block count too small");
362 if (inodes < 1) errx(1, "Inode count too small");
364 nrblocks = blocks;
365 nrinodes = inodes;
367 umap_array_elements = 1 + blocks/8;
368 if(!(umap_array = malloc(umap_array_elements)))
369 err(1, "can't allocate block bitmap (%u bytes).",
370 (unsigned)umap_array_elements);
372 /* Open special. */
373 special(argv[--optind], insertmode);
375 if (!donttest) {
376 uint16_t *testb;
377 ssize_t w;
379 testb = alloc_block();
381 /* Try writing the last block of partition or diskette. */
382 mkfs_seek((uint64_t)(blocks - 1) * block_size, SEEK_SET);
383 testb[0] = 0x3245;
384 testb[1] = 0x11FF;
385 testb[block_size/2-1] = 0x1F2F;
386 w=mkfs_write(testb, block_size);
387 sync(); /* flush write, so if error next read fails */
388 mkfs_seek((uint64_t)(blocks - 1) * block_size, SEEK_SET);
389 testb[0] = 0;
390 testb[1] = 0;
391 testb[block_size/2-1] = 0;
392 nread = read(fd, testb, block_size);
393 if (nread != block_size || testb[0] != 0x3245 || testb[1] != 0x11FF ||
394 testb[block_size/2-1] != 0x1F2F) {
395 warn("nread = %d\n", nread);
396 warnx("testb = 0x%x 0x%x 0x%x\n",
397 testb[0], testb[1], testb[block_size-1]);
398 errx(1, "File system is too big for minor device (read)");
400 mkfs_seek((uint64_t)(blocks - 1) * block_size, SEEK_SET);
401 testb[0] = 0;
402 testb[1] = 0;
403 testb[block_size/2-1] = 0;
404 mkfs_write(testb, block_size);
405 mkfs_seek(0L, SEEK_SET);
406 free(testb);
409 /* Make the file-system */
411 put_block(BOOT_BLOCK, zero); /* Write a null boot block. */
412 put_block(BOOT_BLOCK+1, zero); /* Write another null block. */
414 super(nrblocks >> zone_shift, inodes);
416 root_inum = alloc_inode(mode, usrid, grpid);
417 rootdir(root_inum);
418 if (simple == 0) eat_dir(root_inum);
420 if (print) print_fs();
421 else if (verbose > 1) {
422 if (zone_shift)
423 fprintf(stderr, "%d inodes used. %u zones (%u blocks) used.\n",
424 (int)next_inode-1, next_zone, next_zone*zone_per_block);
425 else
426 fprintf(stderr, "%d inodes used. %u zones used.\n",
427 (int)next_inode-1, next_zone);
430 if(insertmode) printf("%"PRIu64"\n", written_fs_size);
432 return(0);
434 /* NOTREACHED */
435 } /* end main */
437 /*================================================================
438 * detect_fs_size - determine image size dynamically
439 *===============================================================*/
440 void
441 detect_fs_size(struct fs_size * fssize)
443 int prev_lct = lct;
444 off_t point = ftell(proto);
445 block_t initb;
446 zone_t initz;
448 fssize->inocount = 1; /* root directory node */
449 fssize->zonecount = 0;
450 fssize->blockcount = 0;
452 sizeup_dir(fssize);
454 initb = bitmapsize(1 + fssize->inocount, block_size);
455 initb += bitmapsize(fssize->zonecount, block_size);
456 initb += START_BLOCK;
457 initb += (fssize->inocount + inodes_per_block - 1) / inodes_per_block;
458 initz = (initb + zone_per_block - 1) >> zone_shift;
460 fssize->blockcount = initb+ fssize->zonecount;
461 lct = prev_lct;
462 fseek(proto, point, SEEK_SET);
465 void
466 sizeup_dir(struct fs_size * fssize)
468 char *token[MAX_TOKENS], *p;
469 char line[LINE_LEN];
470 FILE *f;
471 off_t size;
472 int dir_entries = 2;
473 zone_t dir_zones = 0, fzones, indirects;
475 while (1) {
476 get_line(line, token);
477 p = token[0];
478 if (*p == '$') {
479 dir_zones = (dir_entries / (NR_DIR_ENTRIES(block_size) * zone_per_block));
480 if(dir_entries % (NR_DIR_ENTRIES(block_size) * zone_per_block))
481 dir_zones++;
482 if(dir_zones > NR_DZONES)
483 dir_zones++; /* Max single indir */
484 fssize->zonecount += dir_zones;
485 return;
488 p = token[1];
489 fssize->inocount++;
490 dir_entries++;
492 if (*p == 'd') {
493 sizeup_dir(fssize);
494 } else if (*p == 'b' || *p == 'c') {
496 } else if (*p == 's') {
497 fssize->zonecount++; /* Symlink contents is always stored a block */
498 } else {
499 if ((f = fopen(token[4], "rb")) == NULL) {
500 /* on minix natively, allow EACCES and skip the entry.
501 * while crossbuilding, always fail on error.
503 #ifdef __minix
504 if(errno == EACCES)
505 warn("dynamic sizing: can't open %s", token[4]);
506 else
507 #endif
508 err(1, "dynamic sizing: can't open %s", token[4]);
509 } else if (fseek(f, 0, SEEK_END) < 0) {
510 pexit("dynamic size detection failed: seek to end of %s",
511 token[4]);
512 } else if ( (size = ftell(f)) == (off_t)(-1)) {
513 pexit("dynamic size detection failed: can't tell size of %s",
514 token[4]);
515 } else {
516 fclose(f);
517 fzones = roundup(size, zone_size) / zone_size;
518 indirects = 0;
519 /* XXX overflow? fzones is u32, size is potentially 64-bit */
520 if (fzones > NR_DZONES)
521 indirects++; /* single indirect needed */
522 if (fzones > nr_indirzones) {
523 /* Each further group of 'indir_per_zone'
524 * needs one supplementary indirect zone:
526 indirects += roundup(fzones - nr_indirzones,
527 indir_per_zone) / indir_per_zone;
528 indirects++; /* + double indirect needed!*/
530 fssize->zonecount += fzones + indirects;
536 /*================================================================
537 * sizeup - determine device size
538 *===============================================================*/
539 block_t
540 sizeup(char * device)
542 block_t d;
543 #if defined(__minix)
544 uint64_t bytes, resize;
545 uint32_t rem;
546 #else
547 off_t size;
548 #endif
551 if ((fd = open(device, O_RDONLY)) == -1) {
552 if (errno != ENOENT)
553 perror("sizeup open");
554 return 0;
557 #if defined(__minix)
558 if(minix_sizeup(device, &bytes) < 0) {
559 perror("sizeup");
560 return 0;
563 d = (uint32_t)(bytes / block_size);
564 rem = (uint32_t)(bytes % block_size);
566 resize = ((uint64_t)d * block_size) + rem;
567 if(resize != bytes) {
568 /* Assume block_t is unsigned */
569 d = (block_t)(-1ul);
570 fprintf(stderr, "%s: truncating FS at %lu blocks\n",
571 progname, (unsigned long)d);
573 #else
574 size = mkfs_seek(0, SEEK_END);
575 /* Assume block_t is unsigned */
576 if (size / block_size > (block_t)(-1ul)) {
577 d = (block_t)(-1ul);
578 fprintf(stderr, "%s: truncating FS at %lu blocks\n",
579 progname, (unsigned long)d);
580 } else
581 d = size / block_size;
582 #endif
584 return d;
588 * copied from fslib
590 static int
591 bitmapsize(bit_t nr_bits, size_t blk_size)
593 block_t nr_blocks;
595 nr_blocks = nr_bits / FS_BITS_PER_BLOCK(blk_size);
596 if (nr_blocks * FS_BITS_PER_BLOCK(blk_size) < nr_bits)
597 ++nr_blocks;
598 return(nr_blocks);
601 /*================================================================
602 * super - construct a superblock
603 *===============================================================*/
605 void
606 super(zone_t zones, ino_t inodes)
608 block_t inodeblks, initblks, i;
609 unsigned long nb;
610 long long ind_per_zone, zo;
611 void *buf;
612 struct super_block *sup;
614 sup = buf = alloc_block();
616 #ifdef MFSFLAG_CLEAN
617 /* The assumption is that mkfs will create a clean FS. */
618 sup->s_flags = MFSFLAG_CLEAN;
619 #endif
621 sup->s_ninodes = inodes;
622 /* Check for overflow; cannot happen on V3 file systems */
623 if(inodes != sup->s_ninodes)
624 errx(1, "Too much inodes for that version of Minix FS.");
625 sup->s_nzones = 0; /* not used in V2 - 0 forces errors early */
626 sup->s_zones = zones;
627 /* Check for overflow; can only happen on V1 file systems */
628 if(zones != sup->s_zones)
629 errx(1, "Too much zones (blocks) for that version of Minix FS.");
631 #ifndef MFS_STATIC_BLOCK_SIZE
632 #define BIGGERBLOCKS "Please try a larger block size for an FS of this size."
633 #else
634 #define BIGGERBLOCKS "Please use MinixFS V3 for an FS of this size."
635 #endif
636 sup->s_imap_blocks = nb = bitmapsize(1 + inodes, block_size);
637 /* Checks for an overflow: nb is uint32_t while s_imap_blocks is of type
638 * int16_t */
639 if(sup->s_imap_blocks != nb) {
640 errx(1, "too many inode bitmap blocks.\n" BIGGERBLOCKS);
642 sup->s_zmap_blocks = nb = bitmapsize(zones, block_size);
643 /* Idem here check for overflow */
644 if(nb != sup->s_zmap_blocks) {
645 errx(1, "too many block bitmap blocks.\n" BIGGERBLOCKS);
647 inode_offset = START_BLOCK + sup->s_imap_blocks + sup->s_zmap_blocks;
648 inodeblks = (inodes + inodes_per_block - 1) / inodes_per_block;
649 initblks = inode_offset + inodeblks;
650 sup->s_firstdatazone_old = nb =
651 (initblks + (1 << zone_shift) - 1) >> zone_shift;
652 if(nb >= zones) errx(1, "bit maps too large");
653 if(nb != sup->s_firstdatazone_old) {
654 /* The field is too small to store the value. Fortunately, the value
655 * can be computed from other fields. We set the on-disk field to zero
656 * to indicate that it must not be used. Eventually, we can always set
657 * the on-disk field to zero, and stop using it.
659 sup->s_firstdatazone_old = 0;
661 sup->s_firstdatazone = nb;
662 zoff = sup->s_firstdatazone - 1;
663 sup->s_log_zone_size = zone_shift;
664 sup->s_magic = SUPER_MAGIC;
665 #ifdef MFS_SUPER_BLOCK_SIZE
666 sup->s_block_size = block_size;
667 /* Check for overflow */
668 if(block_size != sup->MFS_SUPER_BLOCK_SIZE)
669 errx(1, "block_size too large.");
670 sup->s_disk_version = 0;
671 #endif
673 ind_per_zone = (long long) indir_per_zone;
674 zo = NR_DZONES + ind_per_zone + ind_per_zone*ind_per_zone;
675 #ifndef MAX_MAX_SIZE
676 #define MAX_MAX_SIZE (INT32_MAX)
677 #endif
678 if(MAX_MAX_SIZE/block_size < zo) {
679 sup->s_max_size = MAX_MAX_SIZE;
681 else {
682 sup->s_max_size = zo * block_size;
685 if (verbose>1) {
686 fprintf(stderr, "Super block values:\n"
687 "\tnumber of inodes\t%12d\n"
688 "\tnumber of zones \t%12d\n"
689 "\tinode bit map blocks\t%12d\n"
690 "\tzone bit map blocks\t%12d\n"
691 "\tfirst data zone \t%12d\n"
692 "\tblocks per zone shift\t%12d\n"
693 "\tmaximum file size\t%12d\n"
694 "\tmagic number\t\t%#12X\n",
695 sup->s_ninodes, sup->s_zones,
696 sup->s_imap_blocks, sup->s_zmap_blocks, sup->s_firstdatazone,
697 sup->s_log_zone_size, sup->s_max_size, sup->s_magic);
698 #ifdef MFS_SUPER_BLOCK_SIZE
699 fprintf(stderr, "\tblock size\t\t%12d\n", sup->s_block_size);
700 #endif
703 mkfs_seek((off_t) SUPER_BLOCK_BYTES, SEEK_SET);
704 mkfs_write(buf, SUPER_BLOCK_BYTES);
706 /* Clear maps and inodes. */
707 for (i = START_BLOCK; i < initblks; i++) put_block((block_t) i, zero);
709 next_zone = sup->s_firstdatazone;
710 next_inode = 1;
712 zone_map = INODE_MAP + sup->s_imap_blocks;
714 insert_bit(zone_map, 0); /* bit zero must always be allocated */
715 insert_bit((block_t) INODE_MAP, 0); /* inode zero not used but
716 * must be allocated */
718 free(buf);
722 /*================================================================
723 * rootdir - install the root directory
724 *===============================================================*/
725 void
726 rootdir(ino_t inode)
728 zone_t z;
730 z = alloc_zone();
731 add_zone(inode, z, 2 * sizeof(struct direct), current_time);
732 enter_dir(inode, ".", inode);
733 enter_dir(inode, "..", inode);
734 incr_link(inode);
735 incr_link(inode);
738 void
739 enter_symlink(ino_t inode, char *lnk)
741 zone_t z;
742 size_t len;
743 char *buf;
745 buf = alloc_block();
746 z = alloc_zone();
747 len = strlen(lnk);
748 if (len >= block_size)
749 pexit("symlink too long, max length is %u", (unsigned)block_size - 1);
750 strcpy(buf, lnk);
751 put_block((z << zone_shift), buf);
753 add_zone(inode, z, len, current_time);
755 free(buf);
759 /*================================================================
760 * eat_dir - recursively install directory
761 *===============================================================*/
762 void
763 eat_dir(ino_t parent)
765 /* Read prototype lines and set up directory. Recurse if need be. */
766 char *token[MAX_TOKENS], *p;
767 char line[LINE_LEN];
768 int mode, usrid, grpid, maj, min, f;
769 ino_t n;
770 zone_t z;
771 size_t size;
773 while (1) {
774 get_line(line, token);
775 p = token[0];
776 if (*p == '$') return;
777 p = token[1];
778 mode = mode_con(p);
779 usrid = atoi(token[2]);
780 grpid = atoi(token[3]);
781 n = alloc_inode(mode, usrid, grpid);
783 /* Enter name in directory and update directory's size. */
784 enter_dir(parent, token[0], n);
785 incr_size(parent, sizeof(struct direct));
787 /* Check to see if file is directory or special. */
788 incr_link(n);
789 if (*p == 'd') {
790 /* This is a directory. */
791 z = alloc_zone(); /* zone for new directory */
792 add_zone(n, z, 2 * sizeof(struct direct), current_time);
793 enter_dir(n, ".", n);
794 enter_dir(n, "..", parent);
795 incr_link(parent);
796 incr_link(n);
797 eat_dir(n);
798 } else if (*p == 'b' || *p == 'c') {
799 /* Special file. */
800 maj = atoi(token[4]);
801 min = atoi(token[5]);
802 size = 0;
803 if (token[6]) size = atoi(token[6]);
804 size = block_size * size;
805 add_zone(n, (zone_t) (makedev(maj,min)), size, current_time);
806 } else if (*p == 's') {
807 enter_symlink(n, token[4]);
808 } else {
809 /* Regular file. Go read it. */
810 if ((f = open(token[4], O_RDONLY)) < 0) {
811 /* on minix natively, allow EACCES and skip the entry.
812 * while crossbuilding, always fail on error.
814 #ifdef __minix
815 if(errno == EACCES)
816 warn("Can't open %s", token[4]);
817 else
818 #endif
819 err(1, "Can't open %s", token[4]);
820 } else {
821 eat_file(n, f);
828 /*================================================================
829 * eat_file - copy file to MINIX
830 *===============================================================*/
831 /* Zonesize >= blocksize */
832 void
833 eat_file(ino_t inode, int f)
835 int ct = 0, i, j;
836 zone_t z = 0;
837 char *buf;
838 time_t timeval;
840 buf = alloc_block();
842 do {
843 for (i = 0, j = 0; i < zone_per_block; i++, j += ct) {
844 memset(buf, 0, block_size);
845 if ((ct = read(f, buf, block_size)) > 0) {
846 if (i == 0) z = alloc_zone();
847 put_block((z << zone_shift) + i, buf);
850 timeval = (dflag ? current_time : file_time(f));
851 if (ct) add_zone(inode, z, (size_t) j, timeval);
852 } while (ct == block_size);
853 close(f);
854 free(buf);
858 dir_try_enter(zone_t z, ino_t child, char const *name)
860 struct direct *dir_entry = alloc_block();
861 int r = 0;
862 block_t b;
863 int i, l;
865 b = z << zone_shift;
866 for (l = 0; l < zone_per_block; l++, b++) {
867 get_block(b, dir_entry);
869 for (i = 0; i < NR_DIR_ENTRIES(block_size); i++)
870 if (!dir_entry[i].d_ino)
871 break;
873 if(i < NR_DIR_ENTRIES(block_size)) {
874 r = 1;
875 dir_entry[i].d_ino = child;
876 assert(sizeof(dir_entry[i].d_name) == MFS_DIRSIZ);
877 if (verbose && strlen(name) > MFS_DIRSIZ)
878 fprintf(stderr, "File name %s is too long, truncated\n", name);
879 strncpy(dir_entry[i].d_name, name, MFS_DIRSIZ);
880 put_block(b, dir_entry);
881 break;
885 free(dir_entry);
887 return r;
890 /*================================================================
891 * directory & inode management assist group
892 *===============================================================*/
893 void
894 enter_dir(ino_t parent, char const *name, ino_t child)
896 /* Enter child in parent directory */
897 /* Works for dir > 1 block and zone > block */
898 unsigned int k;
899 block_t b, indir;
900 zone_t z;
901 int off;
902 struct inode *ino;
903 struct inode *inoblock = alloc_block();
904 zone_t *indirblock = alloc_block();
906 assert(!(block_size % sizeof(struct direct)));
908 /* Obtain the inode structure */
909 b = ((parent - 1) / inodes_per_block) + inode_offset;
910 off = (parent - 1) % inodes_per_block;
911 get_block(b, inoblock);
912 ino = inoblock + off;
914 for (k = 0; k < NR_DZONES; k++) {
915 z = ino->i_zone[k];
916 if (z == 0) {
917 z = alloc_zone();
918 ino->i_zone[k] = z;
921 if(dir_try_enter(z, child, __UNCONST(name))) {
922 put_block(b, inoblock);
923 free(inoblock);
924 free(indirblock);
925 return;
929 /* no space in directory using just direct blocks; try indirect */
930 if (ino->i_zone[S_INDIRECT_IDX] == 0)
931 ino->i_zone[S_INDIRECT_IDX] = alloc_zone();
933 indir = ino->i_zone[S_INDIRECT_IDX] << zone_shift;
934 --indir; /* Compensate for ++indir below */
935 for(k = 0; k < (indir_per_zone); k++) {
936 if (k % indir_per_block == 0)
937 get_block(++indir, indirblock);
938 z = indirblock[k % indir_per_block];
939 if(!z) {
940 z = indirblock[k % indir_per_block] = alloc_zone();
941 put_block(indir, indirblock);
943 if(dir_try_enter(z, child, __UNCONST(name))) {
944 put_block(b, inoblock);
945 free(inoblock);
946 free(indirblock);
947 return;
951 pexit("Directory-inode %u beyond single indirect blocks. Could not enter %s",
952 (unsigned)parent, name);
956 void
957 add_zone(ino_t n, zone_t z, size_t bytes, time_t mtime)
959 /* Add zone z to inode n. The file has grown by 'bytes' bytes. */
961 int off, i, j;
962 block_t b;
963 zone_t indir, dindir;
964 struct inode *p, *inode;
965 zone_t *blk, *dblk;
967 assert(inodes_per_block*sizeof(*inode) == block_size);
968 if(!(inode = alloc_block()))
969 err(1, "Couldn't allocate block of inodes");
971 b = ((n - 1) / inodes_per_block) + inode_offset;
972 off = (n - 1) % inodes_per_block;
973 get_block(b, inode);
974 p = &inode[off];
975 p->i_size += bytes;
976 p->i_mtime = mtime;
977 #ifndef MFS_INODE_ONLY_MTIME /* V1 file systems did not have them... */
978 p->i_atime = p->i_ctime = current_time;
979 #endif
980 for (i = 0; i < NR_DZONES; i++)
981 if (p->i_zone[i] == 0) {
982 p->i_zone[i] = z;
983 put_block(b, inode);
984 free(inode);
985 return;
988 assert(indir_per_block*sizeof(*blk) == block_size);
989 if(!(blk = alloc_block()))
990 err(1, "Couldn't allocate indirect block");
992 /* File has grown beyond a small file. */
993 if (p->i_zone[S_INDIRECT_IDX] == 0)
994 p->i_zone[S_INDIRECT_IDX] = alloc_zone();
995 indir = p->i_zone[S_INDIRECT_IDX] << zone_shift;
996 put_block(b, inode);
997 --indir; /* Compensate for ++indir below */
998 for (i = 0; i < (indir_per_zone); i++) {
999 if (i % indir_per_block == 0)
1000 get_block(++indir, blk);
1001 if (blk[i % indir_per_block] == 0) {
1002 blk[i] = z;
1003 put_block(indir, blk);
1004 free(blk);
1005 free(inode);
1006 return;
1010 /* File has grown beyond single indirect; we need a double indirect */
1011 assert(indir_per_block*sizeof(*dblk) == block_size);
1012 if(!(dblk = alloc_block()))
1013 err(1, "Couldn't allocate double indirect block");
1015 if (p->i_zone[D_INDIRECT_IDX] == 0)
1016 p->i_zone[D_INDIRECT_IDX] = alloc_zone();
1017 dindir = p->i_zone[D_INDIRECT_IDX] << zone_shift;
1018 put_block(b, inode);
1019 --dindir; /* Compensate for ++indir below */
1020 for (j = 0; j < (indir_per_zone); j++) {
1021 if (j % indir_per_block == 0)
1022 get_block(++dindir, dblk);
1023 if (dblk[j % indir_per_block] == 0)
1024 dblk[j % indir_per_block] = alloc_zone();
1025 indir = dblk[j % indir_per_block] << zone_shift;
1026 --indir; /* Compensate for ++indir below */
1027 for (i = 0; i < (indir_per_zone); i++) {
1028 if (i % indir_per_block == 0)
1029 get_block(++indir, blk);
1030 if (blk[i % indir_per_block] == 0) {
1031 blk[i] = z;
1032 put_block(dindir, dblk);
1033 put_block(indir, blk);
1034 free(dblk);
1035 free(blk);
1036 free(inode);
1037 return;
1042 pexit("File has grown beyond double indirect");
1046 /* Increment the link count to inode n */
1047 void
1048 incr_link(ino_t n)
1050 int off;
1051 static int enter = 0;
1052 static struct inode *inodes = NULL;
1053 block_t b;
1055 if (enter++) pexit("internal error: recursive call to incr_link()");
1057 b = ((n - 1) / inodes_per_block) + inode_offset;
1058 off = (n - 1) % inodes_per_block;
1060 assert(sizeof(*inodes) * inodes_per_block == block_size);
1061 if(!inodes && !(inodes = alloc_block()))
1062 err(1, "couldn't allocate a block of inodes");
1064 get_block(b, inodes);
1065 inodes[off].i_nlinks++;
1066 /* Check overflow (particularly on V1)... */
1067 if (inodes[off].i_nlinks <= 0)
1068 pexit("Too many links to a directory");
1069 put_block(b, inodes);
1071 enter = 0;
1075 /* Increment the file-size in inode n */
1076 void
1077 incr_size(ino_t n, size_t count)
1079 block_t b;
1080 int off;
1082 b = ((n - 1) / inodes_per_block) + inode_offset;
1083 off = (n - 1) % inodes_per_block;
1085 struct inode *inodes;
1087 assert(inodes_per_block * sizeof(*inodes) == block_size);
1088 if(!(inodes = alloc_block()))
1089 err(1, "couldn't allocate a block of inodes");
1091 get_block(b, inodes);
1092 /* Check overflow; avoid compiler spurious warnings */
1093 if (inodes[off].i_size+(int)count < inodes[off].i_size ||
1094 inodes[off].i_size > MAX_MAX_SIZE-(int)count)
1095 pexit("File has become too big to be handled by MFS");
1096 inodes[off].i_size += count;
1097 put_block(b, inodes);
1098 free(inodes);
1103 /*================================================================
1104 * allocation assist group
1105 *===============================================================*/
1106 static ino_t
1107 alloc_inode(int mode, int usrid, int grpid)
1109 ino_t num;
1110 int off;
1111 block_t b;
1112 struct inode *inodes;
1114 num = next_inode++;
1115 if (num > nrinodes) {
1116 pexit("File system does not have enough inodes (only %llu)", nrinodes);
1118 b = ((num - 1) / inodes_per_block) + inode_offset;
1119 off = (num - 1) % inodes_per_block;
1121 assert(inodes_per_block * sizeof(*inodes) == block_size);
1122 if(!(inodes = alloc_block()))
1123 err(1, "couldn't allocate a block of inodes");
1125 get_block(b, inodes);
1126 if (inodes[off].i_mode) {
1127 pexit("allocation new inode %llu with non-zero mode - this cannot happen",
1128 num);
1130 inodes[off].i_mode = mode;
1131 inodes[off].i_uid = usrid;
1132 inodes[off].i_gid = grpid;
1133 if (verbose && (inodes[off].i_uid != usrid || inodes[off].i_gid != grpid))
1134 fprintf(stderr, "Uid/gid %d.%d do not fit within inode, truncated\n", usrid, grpid);
1135 put_block(b, inodes);
1137 free(inodes);
1139 /* Set the bit in the bit map. */
1140 insert_bit((block_t) INODE_MAP, num);
1141 return(num);
1145 /* Allocate a new zone */
1146 static zone_t
1147 alloc_zone(void)
1149 /* Works for zone > block */
1150 block_t b;
1151 int i;
1152 zone_t z;
1154 z = next_zone++;
1155 b = z << zone_shift;
1156 if (b > nrblocks - zone_per_block)
1157 pexit("File system not big enough for all the files");
1158 for (i = 0; i < zone_per_block; i++)
1159 put_block(b + i, zero); /* give an empty zone */
1161 insert_bit(zone_map, z - zoff);
1162 return z;
1166 /* Insert one bit into the bitmap */
1167 void
1168 insert_bit(block_t map, bit_t bit)
1170 int boff, w, s;
1171 unsigned int bits_per_block;
1172 block_t map_block;
1173 bitchunk_t *buf;
1175 buf = alloc_block();
1177 bits_per_block = FS_BITS_PER_BLOCK(block_size);
1178 map_block = map + bit / bits_per_block;
1179 if (map_block >= inode_offset)
1180 pexit("insertbit invades inodes area - this cannot happen");
1181 boff = bit % bits_per_block;
1183 assert(boff >=0);
1184 assert(boff < FS_BITS_PER_BLOCK(block_size));
1185 get_block(map_block, buf);
1186 w = boff / FS_BITCHUNK_BITS;
1187 s = boff % FS_BITCHUNK_BITS;
1188 buf[w] |= (1 << s);
1189 put_block(map_block, buf);
1191 free(buf);
1195 /*================================================================
1196 * proto-file processing assist group
1197 *===============================================================*/
1198 int mode_con(char *p)
1200 /* Convert string to mode */
1201 int o1, o2, o3, mode;
1202 char c1, c2, c3;
1204 c1 = *p++;
1205 c2 = *p++;
1206 c3 = *p++;
1207 o1 = *p++ - '0';
1208 o2 = *p++ - '0';
1209 o3 = *p++ - '0';
1210 mode = (o1 << 6) | (o2 << 3) | o3;
1211 if (c1 == 'd') mode |= S_IFDIR;
1212 if (c1 == 'b') mode |= S_IFBLK;
1213 if (c1 == 'c') mode |= S_IFCHR;
1214 if (c1 == 's') mode |= S_IFLNK;
1215 if (c1 == 'l') mode |= S_IFLNK; /* just to be somewhat ls-compatible*/
1216 /* XXX note: some other mkfs programs consider L to create hardlinks */
1217 if (c1 == '-') mode |= S_IFREG;
1218 if (c2 == 'u') mode |= S_ISUID;
1219 if (c3 == 'g') mode |= S_ISGID;
1220 /* XXX There are no way to encode S_ISVTX */
1221 return(mode);
1224 void
1225 get_line(char line[LINE_LEN], char *parse[MAX_TOKENS])
1227 /* Read a line and break it up in tokens */
1228 int k;
1229 char c, *p;
1230 int d;
1232 for (k = 0; k < MAX_TOKENS; k++) parse[k] = 0;
1233 memset(line, 0, LINE_LEN);
1234 k = 0;
1235 p = line;
1236 while (1) {
1237 if (++k > LINE_LEN) pexit("Line too long");
1238 d = fgetc(proto);
1239 if (d == EOF) pexit("Unexpected end-of-file");
1240 *p = d;
1241 if (*p == ' ' || *p == '\t') *p = 0;
1242 if (*p == '\n') {
1243 lct++;
1244 *p++ = 0;
1245 *p = '\n';
1246 break;
1248 p++;
1251 k = 0;
1252 p = line;
1253 while (1) {
1254 c = *p++;
1255 if (c == '\n') return;
1256 if (c == 0) continue;
1257 parse[k++] = p - 1;
1258 do {
1259 c = *p++;
1260 } while (c != 0 && c != '\n');
1265 /*================================================================
1266 * other stuff
1267 *===============================================================*/
1270 * Check to see if the special file named 'device' is mounted.
1272 void
1273 check_mtab(const char *device) /* /dev/hd1 or whatever */
1275 #if defined(__minix)
1276 int n, r;
1277 struct stat sb;
1278 char dev[PATH_MAX], mount_point[PATH_MAX],
1279 type[MNTNAMELEN], flags[MNTFLAGLEN];
1281 r= stat(device, &sb);
1282 if (r == -1)
1284 if (errno == ENOENT)
1285 return; /* Does not exist, and therefore not mounted. */
1286 err(1, "stat %s failed", device);
1288 if (!S_ISBLK(sb.st_mode))
1290 /* Not a block device and therefore not mounted. */
1291 return;
1294 if (load_mtab(__UNCONST("mkfs")) < 0) return;
1295 while (1) {
1296 n = get_mtab_entry(dev, mount_point, type, flags);
1297 if (n < 0) return;
1298 if (strcmp(device, dev) == 0) {
1299 /* Can't mkfs on top of a mounted file system. */
1300 errx(1, "%s is mounted on %s", device, mount_point);
1303 #else
1304 (void) device; /* shut up warnings about unused variable... */
1305 #endif
1309 time_t
1310 file_time(int f)
1312 struct stat statbuf;
1314 if (!fstat(f, &statbuf))
1315 return current_time;
1316 if (statbuf.st_mtime<0 || statbuf.st_mtime>(uint32_t)(-1))
1317 return current_time;
1318 return(statbuf.st_mtime);
1322 __dead void
1323 pexit(char const * s, ...)
1325 va_list va;
1327 va_start(va, s);
1328 vwarn(s, va);
1329 va_end(va);
1330 if (lct != 0)
1331 warnx("Line %d being processed when error detected.\n", lct);
1332 exit(2);
1336 void *
1337 alloc_block(void)
1339 void *buf;
1341 if(!(buf = malloc(block_size))) {
1342 err(1, "couldn't allocate filesystem buffer");
1344 memset(buf, 0, block_size);
1346 return buf;
1349 void
1350 print_fs(void)
1352 int i, j;
1353 ino_t k;
1354 struct inode *inode2;
1355 unsigned short *usbuf;
1356 block_t b;
1357 struct direct *dir;
1359 assert(inodes_per_block * sizeof(*inode2) == block_size);
1360 if(!(inode2 = alloc_block()))
1361 err(1, "couldn't allocate a block of inodes");
1363 assert(NR_DIR_ENTRIES(block_size)*sizeof(*dir) == block_size);
1364 if(!(dir = alloc_block()))
1365 err(1, "couldn't allocate a block of directory entries");
1367 usbuf = alloc_block();
1368 get_super_block(usbuf);
1369 printf("\nSuperblock: ");
1370 for (i = 0; i < 8; i++) printf("%06ho ", usbuf[i]);
1371 printf("\n ");
1372 for (i = 0; i < 8; i++) printf("%#04hX ", usbuf[i]);
1373 printf("\n ");
1374 for (i = 8; i < 15; i++) printf("%06ho ", usbuf[i]);
1375 printf("\n ");
1376 for (i = 8; i < 15; i++) printf("%#04hX ", usbuf[i]);
1377 get_block((block_t) INODE_MAP, usbuf);
1378 printf("...\nInode map: ");
1379 for (i = 0; i < 9; i++) printf("%06ho ", usbuf[i]);
1380 get_block((block_t) zone_map, usbuf);
1381 printf("...\nZone map: ");
1382 for (i = 0; i < 9; i++) printf("%06ho ", usbuf[i]);
1383 printf("...\n");
1385 free(usbuf);
1386 usbuf = NULL;
1388 k = 0;
1389 for (b = inode_offset; k < nrinodes; b++) {
1390 get_block(b, inode2);
1391 for (i = 0; i < inodes_per_block; i++) {
1392 k = inodes_per_block * (int) (b - inode_offset) + i + 1;
1393 /* Lint but OK */
1394 if (k > nrinodes) break;
1396 if (inode2[i].i_mode != 0) {
1397 printf("Inode %3u: mode=", (unsigned)k);
1398 printf("%06o", (unsigned)inode2[i].i_mode);
1399 printf(" uid=%2d gid=%2d size=",
1400 (int)inode2[i].i_uid, (int)inode2[i].i_gid);
1401 printf("%6ld", (long)inode2[i].i_size);
1402 printf(" zone[0]=%u\n", (unsigned)inode2[i].i_zone[0]);
1404 if ((inode2[i].i_mode & S_IFMT) == S_IFDIR) {
1405 /* This is a directory */
1406 get_block(inode2[i].i_zone[0] << zone_shift, dir);
1407 for (j = 0; j < NR_DIR_ENTRIES(block_size); j++)
1408 if (dir[j].d_ino)
1409 printf("\tInode %2u: %s\n",
1410 (unsigned)dir[j].d_ino,
1411 dir[j].d_name);
1417 if (zone_shift)
1418 printf("%d inodes used. %u zones (%u blocks) used.\n",
1419 (int)next_inode-1, next_zone, next_zone*zone_per_block);
1420 else
1421 printf("%d inodes used. %u zones used.\n", (int)next_inode-1, next_zone);
1422 free(dir);
1423 free(inode2);
1428 * The first time a block is read, it returns all 0s, unless there has
1429 * been a write. This routine checks to see if a block has been accessed.
1432 read_and_set(block_t n)
1434 int w, s, mask, r;
1436 w = n / 8;
1438 assert(n < nrblocks);
1439 if(w >= umap_array_elements) {
1440 errx(1, "umap array too small - this can't happen");
1442 s = n % 8;
1443 mask = 1 << s;
1444 r = (umap_array[w] & mask ? 1 : 0);
1445 umap_array[w] |= mask;
1446 return(r);
1449 __dead void
1450 usage(void)
1452 fprintf(stderr, "Usage: %s [-dltv] [-b blocks] [-i inodes]\n"
1453 "\t[-z zone_shift] [-I offset] [-x extra] [-B blocksize] special [proto]\n",
1454 progname);
1455 exit(4);
1458 void
1459 special(char * string, int insertmode)
1461 int openmode = O_RDWR;
1462 if(!insertmode) openmode |= O_TRUNC;
1463 fd = open(string, O_RDWR | O_CREAT, 0644);
1464 if (fd < 0) err(1, "Can't open special file %s", string);
1465 mkfs_seek(0, SEEK_SET);
1470 /* Read a block. */
1471 void
1472 get_block(block_t n, void *buf)
1474 ssize_t k;
1476 /* First access returns a zero block */
1477 if (read_and_set(n) == 0) {
1478 memcpy(buf, zero, block_size);
1479 return;
1481 mkfs_seek((uint64_t)(n) * block_size, SEEK_SET);
1482 k = read(fd, buf, block_size);
1483 if (k != block_size)
1484 pexit("get_block couldn't read block #%u", (unsigned)n);
1487 /* Read the super block. */
1488 void
1489 get_super_block(void *buf)
1491 ssize_t k;
1493 mkfs_seek((off_t) SUPER_BLOCK_BYTES, SEEK_SET);
1494 k = read(fd, buf, SUPER_BLOCK_BYTES);
1495 if (k != SUPER_BLOCK_BYTES)
1496 err(1, "get_super_block couldn't read super block");
1499 /* Write a block. */
1500 void
1501 put_block(block_t n, void *buf)
1504 (void) read_and_set(n);
1506 mkfs_seek((uint64_t)(n) * block_size, SEEK_SET);
1507 mkfs_write(buf, block_size);
1510 static ssize_t
1511 mkfs_write(void * buf, size_t count)
1513 uint64_t fssize;
1514 ssize_t w;
1516 /* Perform & check write */
1517 w = write(fd, buf, count);
1518 if(w < 0)
1519 err(1, "mkfs_write: write failed");
1520 if(w != count)
1521 errx(1, "mkfs_write: short write: %zd != %zu", w, count);
1523 /* Check if this has made the FS any bigger; count bytes after offset */
1524 fssize = mkfs_seek(0, SEEK_CUR);
1526 assert(fssize >= fs_offset_bytes);
1527 fssize -= fs_offset_bytes;
1528 fssize = roundup(fssize, block_size);
1529 if(fssize > written_fs_size)
1530 written_fs_size = fssize;
1532 return w;
1535 /* Seek to position in FS we're creating. */
1536 static uint64_t
1537 mkfs_seek(uint64_t pos, int whence)
1539 if(whence == SEEK_SET) pos += fs_offset_bytes;
1540 off_t newpos;
1541 if((newpos=lseek(fd, pos, whence)) == (off_t) -1)
1542 err(1, "mkfs_seek: lseek failed");
1543 return newpos;