xref: /netbsd-src/sbin/fsck_lfs/setup.c (revision 3b435a73967be44dfb4a27315acd72bfacde430c)
1 /*	$NetBSD: setup.c,v 1.3 1999/07/03 19:55:03 kleink Exp $	*/
2 
3 /*
4  * Copyright (c) 1980, 1986, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 /* #define DKTYPENAMES */
37 #define FSTYPENAMES
38 #include <sys/param.h>
39 #include <sys/time.h>
40 #include <sys/stat.h>
41 #include <sys/ioctl.h>
42 #include <sys/disklabel.h>
43 #include <sys/file.h>
44 
45 #include <ufs/ufs/dinode.h>
46 #include <sys/mount.h> /* XXX ufs/lfs/lfs.h should include this for us */
47 #include <ufs/lfs/lfs.h>
48 #include <ufs/lfs/lfs_extern.h>
49 
50 #include <ctype.h>
51 #include <err.h>
52 #include <errno.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 
57 #include "fsck.h"
58 #include "extern.h"
59 #include "fsutil.h"
60 
61 struct bufarea asblk;
62 extern struct dinode **din_table;
63 extern SEGUSE *seg_table;
64 #define altsblock (*asblk.b_un.b_fs)
65 #define POWEROF2(num)	(((num) & ((num) - 1)) == 0)
66 
67 void badsb __P((int, char *));
68 int calcsb __P((const char *, int, struct lfs *));
69 static struct disklabel *getdisklabel __P((const char *, int));
70 static int readsb __P((int));
71 int lfs_maxino(void);
72 
73 #ifdef DKTYPENAMES
74 int useless __P((void));
75 
76 int
77 useless(void)
78 {
79 	char **foo = (char **)dktypenames;
80 	char **bar = (char **)fscknames;
81 
82 	return foo-bar;
83 }
84 #endif
85 
86 int
87 setup(dev)
88 	const char *dev;
89 {
90 	long bmapsize;
91 	struct disklabel *lp;
92 #if 0
93 	long i;
94 	off_t sizepb;
95 #endif
96 	struct stat statb;
97 	struct lfs proto;
98 	int doskipclean;
99 	u_int64_t maxfilesize;
100         struct lfs *sb0;
101 
102 	havesb = 0;
103 	fswritefd = -1;
104 	doskipclean = skipclean;
105 	if (stat(dev, &statb) < 0) {
106 		printf("Can't stat %s: %s\n", dev, strerror(errno));
107 		return (0);
108 	}
109 	if (!S_ISCHR(statb.st_mode)) {
110 		pfatal("%s is not a character device", dev);
111 		if (reply("CONTINUE") == 0)
112 			return (0);
113 	}
114 	if ((fsreadfd = open(dev, O_RDONLY)) < 0) {
115 		printf("Can't open %s: %s\n", dev, strerror(errno));
116 		return (0);
117 	}
118 	if (preen == 0)
119 		printf("** %s", dev);
120 	if (nflag || (fswritefd = open(dev, O_WRONLY)) < 0) {
121 		fswritefd = -1;
122 		if (preen)
123 			pfatal("NO WRITE ACCESS");
124 		printf(" (NO WRITE)");
125 	}
126 	if (preen == 0)
127 		printf("\n");
128 	fsmodified = 0;
129 	lfdir = 0;
130 	initbarea(&sblk);
131 	initbarea(&asblk);
132 	sblk.b_un.b_buf = malloc(LFS_SBPAD);
133 	asblk.b_un.b_buf = malloc(LFS_SBPAD);
134 	if (sblk.b_un.b_buf == NULL || asblk.b_un.b_buf == NULL)
135 		errexit("cannot allocate space for superblock\n");
136 	if ((lp = getdisklabel((char *)NULL, fsreadfd)) != NULL)
137 		dev_bsize = secsize = lp->d_secsize;
138 	else
139 		dev_bsize = secsize = DEV_BSIZE;
140 
141 	/*
142 	 * Read in the superblock, looking for alternates if necessary
143 	 */
144 	if (readsb(1) == 0) {
145 		if (bflag || preen || calcsb(dev, fsreadfd, &proto) == 0)
146 			return(0);
147 		if (reply("LOOK FOR ALTERNATE SUPERBLOCKS") == 0)
148 			return (0);
149 #if 0 /* XXX find the LFS way to do this */
150 		for (cg = 0; cg < proto.lfs_ncg; cg++) {
151 			bflag = fsbtodb(&proto, cgsblock(&proto, cg));
152 			if (readsb(0) != 0)
153 				break;
154 		}
155 		if (cg >= proto.lfs_ncg) {
156 			printf("%s %s\n%s %s\n%s %s\n",
157 				"SEARCH FOR ALTERNATE SUPER-BLOCK",
158 				"FAILED. YOU MUST USE THE",
159 				"-b OPTION TO FSCK_FFS TO SPECIFY THE",
160 				"LOCATION OF AN ALTERNATE",
161 				"SUPER-BLOCK TO SUPPLY NEEDED",
162 				"INFORMATION; SEE fsck_ffs(8).");
163 			return(0);
164 		}
165 #else
166 		pwarn("XXX Can't look for alternate superblocks yet\n");
167 		return(0);
168 #endif
169 		doskipclean = 0;
170 		pwarn("USING ALTERNATE SUPERBLOCK AT %d\n", bflag);
171 	}
172 	if(bflag==0) {
173 		/*
174 		 * Even if that superblock read in properly, it may not
175 		 * be guaranteed to point to a complete checkpoint.
176 		 * Read in the second superblock too, and take whichever
177 		 * of the two is *less* recent. --ks
178 		 */
179 		sb0 = malloc(sizeof(*sb0));
180 		memcpy(sb0,&sblock,sizeof(*sb0));
181 			bflag = sblock.lfs_sboffs[1];
182 			if(readsb(1)==0) {
183 				pwarn("COULDN'T READ ALT SUPERBLOCK AT BLK %d",bflag);
184 				if (reply("ASSUME PRIMARY SUPERBLOCK IS GOOD") == 0) {
185 					return (0);
186 				} else { /* use primary as good */
187 					memcpy(&sblock,sb0,sizeof(*sb0)); /* XXX cheating? */
188 				}
189 			} else {
190 				if(debug)
191 					pwarn("sb0 %d, sb1 %d\n",sb0->lfs_tstamp,sblock.lfs_tstamp);
192 				if(sblock.lfs_tstamp >= sb0->lfs_tstamp) {
193 					memcpy(&sblock,sb0,sizeof(*sb0)); /* XXX cheating? */
194 				} else {
195 					pwarn("Using alt superblock, disk addr 0x%x\n",
196 					      bflag);
197 				}
198 			}
199 		free(sb0);
200 	}
201 	if(debug) {
202         	printf("dev_bsize = %lu\n",dev_bsize);
203                 printf("lfs_bsize = %lu\n",(unsigned long)sblock.lfs_bsize);
204                 printf("lfs_fsize = %lu\n",(unsigned long)sblock.lfs_fsize);
205                 printf("lfs_frag  = %lu\n",(unsigned long)sblock.lfs_frag);
206                 printf("INOPB(fs) = %lu\n",(unsigned long)INOPB(&sblock));
207         	/* printf("fsbtodb(fs,1) = %lu\n",fsbtodb(&sblock,1)); */
208 	}
209 #if 0 /* FFS-specific fs-clean check */
210 	if (debug)
211 		printf("clean = %d\n", sblock.lfs_clean);
212 	if (sblock.lfs_clean & FS_ISCLEAN) {
213 		if (doskipclean) {
214 			pwarn("%sile system is clean; not checking\n",
215 			    preen ? "f" : "** F");
216 			return (-1);
217 		}
218 		if (!preen)
219 			pwarn("** File system is already clean\n");
220 	}
221 	maxino = sblock.lfs_ncg * sblock.lfs_ipg;
222 #else
223 #if 0
224         /* XXX - count the number of inodes here */
225         maxino = sblock.lfs_nfiles+2;
226 #else
227         initbarea(&iblk);
228         iblk.b_un.b_buf = malloc(sblock.lfs_bsize);
229         if(bread(fsreadfd, (char *)iblk.b_un.b_buf,
230                  sblock.lfs_idaddr,
231                  (long)sblock.lfs_bsize) != 0)
232         {
233             printf("Couldn't read disk block %d\n",sblock.lfs_idaddr);
234             exit(1);
235         }
236         maxino = lfs_maxino();
237 #endif
238 	if (debug)
239         	printf("maxino=%d\n",maxino);
240         din_table = (struct dinode **)malloc(maxino*sizeof(*din_table));
241         memset(din_table,0,maxino*sizeof(*din_table));
242         seg_table = (SEGUSE *)malloc(sblock.lfs_nseg * sizeof(SEGUSE));
243         memset(seg_table,0,sblock.lfs_nseg * sizeof(SEGUSE));
244 #endif
245 	maxfsblock = sblock.lfs_size * (sblock.lfs_bsize / dev_bsize);
246 #if 0
247 	sizepb = sblock.lfs_bsize;
248 	maxfilesize = sblock.lfs_bsize * NDADDR - 1;
249 	for (i = 0; i < NIADDR; i++) {
250 		sizepb *= NINDIR(&sblock);
251 		maxfilesize += sizepb;
252 	}
253         maxfilesize++; /* XXX */
254 #else /* LFS way */
255 {
256 u_quad_t maxtable[] = {
257         /*    1 */ -1,
258         /*    2 */ -1,
259         /*    4 */ -1,
260         /*    8 */ -1,
261         /*   16 */ -1,
262         /*   32 */ -1,
263         /*   64 */ -1,
264         /*  128 */ -1,
265         /*  256 */ -1,
266         /*  512 */ NDADDR + 128 + 128 * 128 + 128 * 128 * 128,
267         /* 1024 */ NDADDR + 256 + 256 * 256 + 256 * 256 * 256,
268         /* 2048 */ NDADDR + 512 + 512 * 512 + 512 * 512 * 512,
269         /* 4096 */ NDADDR + 1024 + 1024 * 1024 + 1024 * 1024 * 1024,
270         /* 8192 */ 1 << 31,
271         /* 16 K */ 1 << 31,
272         /* 32 K */ 1 << 31,
273 };
274 	maxfilesize = maxtable[sblock.lfs_bshift] << sblock.lfs_bshift;
275 }
276 #endif
277 	if ((sblock.lfs_minfree < 0 || sblock.lfs_minfree > 99)) {
278 		pfatal("IMPOSSIBLE MINFREE=%d IN SUPERBLOCK",
279 			sblock.lfs_minfree);
280 		if (reply("SET TO DEFAULT") == 1) {
281 			sblock.lfs_minfree = 10;
282 			sbdirty();
283 		}
284 	}
285         /* XXX used to be ~(sblock.lfs_bsize - 1) */
286 	if (sblock.lfs_bmask != sblock.lfs_bsize - 1) {
287 		pwarn("INCORRECT BMASK=%x IN SUPERBLOCK (should be %x)",
288 			(unsigned int)sblock.lfs_bmask,
289 			(unsigned int)sblock.lfs_bsize - 1);
290 		sblock.lfs_bmask = sblock.lfs_bsize - 1;
291 		if (preen)
292 			printf(" (FIXED)\n");
293 		if (preen || reply("FIX") == 1) {
294 			sbdirty();
295 			dirty(&asblk);
296 		}
297 	}
298 #if 0 /* FFS-specific checks */
299 	if (sblock.lfs_fmask != ~(sblock.lfs_fsize - 1)) {
300 		pwarn("INCORRECT FMASK=%x IN SUPERBLOCK",
301 			sblock.lfs_fmask);
302 		sblock.lfs_fmask = ~(sblock.lfs_fsize - 1);
303 		if (preen)
304 			printf(" (FIXED)\n");
305 		if (preen || reply("FIX") == 1) {
306 			sbdirty();
307 			dirty(&asblk);
308 		}
309 	}
310 #endif
311 		if (sblock.lfs_maxfilesize != maxfilesize) {
312 			pwarn("INCORRECT MAXFILESIZE=%qu IN SUPERBLOCK (should be %qu)",
313 				(unsigned long long)sblock.lfs_maxfilesize,
314 				(unsigned long long)maxfilesize);
315 			sblock.lfs_maxfilesize = maxfilesize;
316 			if (preen)
317 				printf(" (FIXED)\n");
318 			if (preen || reply("FIX") == 1) {
319 				sbdirty();
320 				dirty(&asblk);
321 			}
322 		}
323 		if (sblock.lfs_maxsymlinklen != MAXSYMLINKLEN) {
324 			pwarn("INCORRECT MAXSYMLINKLEN=%d IN SUPERBLOCK",
325 				sblock.lfs_maxsymlinklen);
326 			sblock.lfs_maxsymlinklen = MAXSYMLINKLEN;
327 			if (preen)
328 				printf(" (FIXED)\n");
329 			if (preen || reply("FIX") == 1) {
330 				sbdirty();
331 				dirty(&asblk);
332 			}
333 		}
334 		newinofmt = 1;
335 	/*
336 	 * allocate and initialize the necessary maps
337 	 */
338 #ifndef VERBOSE_BLOCKMAP
339 	bmapsize = roundup(howmany(maxfsblock, NBBY), sizeof(int16_t));
340         blockmap = malloc((unsigned)bmapsize * sizeof (char));
341         bzero(blockmap, bmapsize * sizeof(char));
342 #else
343 	bmapsize = maxfsblock*sizeof(ino_t);
344         blockmap = (ino_t *)malloc(maxfsblock * sizeof (ino_t));
345         bzero(blockmap, maxfsblock * sizeof(ino_t));
346 #endif
347 	if (blockmap == NULL) {
348 		printf("cannot alloc %u bytes for blockmap\n",
349 		    (unsigned)bmapsize);
350 		goto badsblabel;
351 	}
352 	statemap = calloc((unsigned)(maxino + 1), sizeof(char));
353 	if (statemap == NULL) {
354 		printf("cannot alloc %u bytes for statemap\n",
355 		    (unsigned)(maxino + 1));
356 		goto badsblabel;
357 	}
358 	typemap = calloc((unsigned)(maxino + 1), sizeof(char));
359 	if (typemap == NULL) {
360 		printf("cannot alloc %u bytes for typemap\n",
361 		    (unsigned)(maxino + 1));
362 		goto badsblabel;
363 	}
364 	lncntp = (int16_t *)calloc((unsigned)(maxino + 1), sizeof(int16_t));
365 	if (lncntp == NULL) {
366 		printf("cannot alloc %lu bytes for lncntp\n",
367 		    (unsigned long)(maxino + 1) * sizeof(int16_t));
368 		goto badsblabel;
369 	}
370 	bufinit();
371 	return (1);
372 
373 badsblabel:
374 	ckfini(0);
375 	return (0);
376 }
377 
378 /*
379  * Read in the LFS super block and its summary info.
380  */
381 static int
382 readsb(listerr)
383 	int listerr;
384 {
385 	daddr_t super = bflag ? bflag : LFS_LABELPAD / dev_bsize;
386         u_int32_t checksum;
387 
388 	if (bread(fsreadfd, (char *)&sblock, super, (long)LFS_SBPAD) != 0)
389 		return (0);
390 
391 	sblk.b_bno = super;
392 	sblk.b_size = LFS_SBPAD;
393 	/*
394 	 * run a few consistency checks of the super block
395 	 */
396 	if (sblock.lfs_magic != LFS_MAGIC)
397 		{ badsb(listerr, "MAGIC NUMBER WRONG"); return (0); }
398 
399         /* checksum */
400         checksum = lfs_sb_cksum(&(sblock.lfs_dlfs));
401         if(sblock.lfs_cksum != checksum)
402         {
403             printf("Superblock checksum (%lu) does not match computed checksum %lu\n",
404                    (unsigned long)sblock.lfs_cksum, (unsigned long)checksum);
405         }
406 
407 #if 0 /* XXX - replace these checks with appropriate LFS sanity checks */
408 	if (sblock.lfs_ncg < 1)
409 		{ badsb(listerr, "NCG OUT OF RANGE"); return (0); }
410 	if (sblock.lfs_cpg < 1)
411 		{ badsb(listerr, "CPG OUT OF RANGE"); return (0); }
412 	if (sblock.lfs_ncg * sblock.lfs_cpg < sblock.lfs_ncyl ||
413 	    (sblock.lfs_ncg - 1) * sblock.lfs_cpg >= sblock.lfs_ncyl)
414 		{ badsb(listerr, "NCYL LESS THAN NCG*CPG"); return (0); }
415 	if (sblock.lfs_sbsize > SBSIZE)
416 		{ badsb(listerr, "SIZE PREPOSTEROUSLY LARGE"); return (0); }
417 #endif
418 	/*
419 	 * Compute block size that the filesystem is based on,
420 	 * according to fsbtodb, and adjust superblock block number
421 	 * so we can tell if this is an alternate later.
422 	 */
423 	super *= dev_bsize;
424 #if 0
425 	dev_bsize = sblock.lfs_bsize / fsbtodb(&sblock, 1);
426 #endif
427 	sblk.b_bno = super / dev_bsize;
428 	if (bflag) {
429 		havesb = 1;
430 		return (1);
431 	}
432 #if 0 /* XXX - for now skip the alt. superblock test as well */
433 	/*
434 	 * Set all possible fields that could differ, then do check
435 	 * of whole super block against an alternate super block.
436 	 * When an alternate super-block is specified this check is skipped.
437 	 */
438 	getblk(&asblk, cgsblock(&sblock, sblock.lfs_ncg - 1), sblock.lfs_sbsize);
439 	if (asblk.b_errs)
440 		return (0);
441 	altsblock.lfs_firstfield = sblock.lfs_firstfield;
442 	altsblock.lfs_fscktime = sblock.lfs_fscktime;
443 	altsblock.lfs_time = sblock.lfs_time;
444 	altsblock.lfs_cstotal = sblock.lfs_cstotal;
445 	altsblock.lfs_cgrotor = sblock.lfs_cgrotor;
446 	altsblock.lfs_fmod = sblock.lfs_fmod;
447 	altsblock.lfs_clean = sblock.lfs_clean;
448 	altsblock.lfs_ronly = sblock.lfs_ronly;
449 	altsblock.lfs_flags = sblock.lfs_flags;
450 	altsblock.lfs_maxcontig = sblock.lfs_maxcontig;
451 	altsblock.lfs_minfree = sblock.lfs_minfree;
452 	altsblock.lfs_optim = sblock.lfs_optim;
453 	altsblock.lfs_rotdelay = sblock.lfs_rotdelay;
454 	altsblock.lfs_maxbpg = sblock.lfs_maxbpg;
455 	memcpy(altsblock.lfs_csp, sblock.lfs_csp,
456 		sizeof sblock.lfs_csp);
457 	altsblock.lfs_maxcluster = sblock.lfs_maxcluster;
458 	memcpy(altsblock.lfs_fsmnt, sblock.lfs_fsmnt,
459 		sizeof sblock.lfs_fsmnt);
460 	memcpy(altsblock.lfs_sparecon, sblock.lfs_sparecon,
461 		sizeof sblock.lfs_sparecon);
462 	/*
463 	 * The following should not have to be copied.
464 	 */
465 	altsblock.lfs_fsbtodb = sblock.lfs_fsbtodb;
466 	altsblock.lfs_interleave = sblock.lfs_interleave;
467 	altsblock.lfs_npsect = sblock.lfs_npsect;
468 	altsblock.lfs_nrpos = sblock.lfs_nrpos;
469 	altsblock.lfs_state = sblock.lfs_state;
470 	altsblock.lfs_qbmask = sblock.lfs_qbmask;
471 	altsblock.lfs_qfmask = sblock.lfs_qfmask;
472 	altsblock.lfs_state = sblock.lfs_state;
473 	altsblock.lfs_maxfilesize = sblock.lfs_maxfilesize;
474 	if (memcmp(&sblock, &altsblock, (int)sblock.lfs_sbsize)) {
475 		if (debug) {
476 			long *nlp, *olp, *endlp;
477 
478 			printf("superblock mismatches\n");
479 			nlp = (long *)&altsblock;
480 			olp = (long *)&sblock;
481 			endlp = olp + (sblock.lfs_sbsize / sizeof *olp);
482 			for ( ; olp < endlp; olp++, nlp++) {
483 				if (*olp == *nlp)
484 					continue;
485 				printf("offset %d, original %ld, alternate %ld\n",
486 				    olp - (long *)&sblock, *olp, *nlp);
487 			}
488 		}
489 		badsb(listerr,
490 		"VALUES IN SUPER BLOCK DISAGREE WITH THOSE IN FIRST ALTERNATE");
491 		return (0);
492 	}
493 #endif
494 	havesb = 1;
495 	return (1);
496 }
497 
498 void
499 badsb(listerr, s)
500 	int listerr;
501 	char *s;
502 {
503 
504 	if (!listerr)
505 		return;
506 	if (preen)
507 		printf("%s: ", cdevname());
508 	pfatal("BAD SUPER BLOCK: %s\n", s);
509 }
510 
511 /*
512  * Calculate a prototype superblock based on information in the disk label.
513  * When done the cgsblock macro can be calculated and the fs_ncg field
514  * can be used. Do NOT attempt to use other macros without verifying that
515  * their needed information is available!
516  */
517 int
518 calcsb(dev, devfd, fs)
519 	const char *dev;
520 	int devfd;
521 	register struct lfs *fs;
522 {
523 	register struct disklabel *lp;
524 	register struct partition *pp;
525 	register char *cp;
526 	int i;
527 
528 	cp = strchr(dev, '\0') - 1;
529 	if ((cp == (char *)-1 || (*cp < 'a' || *cp > 'h')) && !isdigit(*cp)) {
530 		pfatal("%s: CANNOT FIGURE OUT FILE SYSTEM PARTITION\n", dev);
531 		return (0);
532 	}
533 	lp = getdisklabel(dev, devfd);
534 	if (isdigit(*cp))
535 		pp = &lp->d_partitions[0];
536 	else
537 		pp = &lp->d_partitions[*cp - 'a'];
538 	if (pp->p_fstype != FS_BSDLFS) {
539 		pfatal("%s: NOT LABELED AS AN LFS FILE SYSTEM (%s)\n",
540 			dev, pp->p_fstype < FSMAXTYPES ?
541 			fstypenames[pp->p_fstype] : "unknown");
542 		return (0);
543 	}
544 	memset(fs, 0, sizeof(struct lfs));
545 	fs->lfs_fsize = pp->p_fsize;
546 	fs->lfs_frag = pp->p_frag;
547 	fs->lfs_size = pp->p_size;
548 	fs->lfs_nspf = fs->lfs_fsize / lp->d_secsize;
549 	dev_bsize = lp->d_secsize;
550 	for (fs->lfs_fsbtodb = 0, i = fs->lfs_nspf; i > 1; i >>= 1)
551 		fs->lfs_fsbtodb++;
552 	return (1);
553 }
554 
555 static struct disklabel *
556 getdisklabel(s, fd)
557 	const char *s;
558 	int	fd;
559 {
560 	static struct disklabel lab;
561 
562 	if (ioctl(fd, DIOCGDINFO, (char *)&lab) < 0) {
563 		if (s == NULL)
564 			return ((struct disklabel *)NULL);
565 		pwarn("ioctl (GCINFO): %s\n", strerror(errno));
566 		errexit("%s: can't read disk label\n", s);
567 	}
568 	return (&lab);
569 }
570