xref: /netbsd-src/sbin/fsck_ffs/setup.c (revision 1ca5c1b28139779176bd5c13ad7c5f25c0bcd5f8)
1 /*	$NetBSD: setup.c,v 1.52 2001/12/19 10:05:20 fvdl 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 #include <sys/cdefs.h>
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)setup.c	8.10 (Berkeley) 5/9/95";
40 #else
41 __RCSID("$NetBSD: setup.c,v 1.52 2001/12/19 10:05:20 fvdl Exp $");
42 #endif
43 #endif /* not lint */
44 
45 #include <sys/param.h>
46 #include <sys/time.h>
47 #include <sys/stat.h>
48 #include <sys/ioctl.h>
49 #define FSTYPENAMES
50 #include <sys/disklabel.h>
51 #include <sys/file.h>
52 
53 #include <ufs/ufs/dinode.h>
54 #include <ufs/ufs/ufs_bswap.h>
55 #include <ufs/ffs/fs.h>
56 #include <ufs/ffs/ffs_extern.h>
57 
58 #include <ctype.h>
59 #include <err.h>
60 #include <errno.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64 
65 #include "fsck.h"
66 #include "extern.h"
67 #include "fsutil.h"
68 
69 #define POWEROF2(num)	(((num) & ((num) - 1)) == 0)
70 
71 static void badsb __P((int, char *));
72 static int calcsb __P((const char *, int, struct fs *));
73 static struct disklabel *getdisklabel __P((const char *, int));
74 static int readsb __P((int));
75 
76 /*
77  * Read in a superblock finding an alternate if necessary.
78  * Return 1 if successful, 0 if unsuccessful, -1 if filesystem
79  * is already clean (preen mode only).
80  */
81 int
82 setup(dev)
83 	const char *dev;
84 {
85 	long cg, size, asked, i, j;
86 	long bmapsize;
87 	struct disklabel *lp;
88 	off_t sizepb;
89 	struct stat statb;
90 	struct fs proto;
91 	int doskipclean;
92 	u_int64_t maxfilesize;
93 	struct csum *ccsp;
94 
95 	havesb = 0;
96 	fswritefd = -1;
97 	doskipclean = skipclean;
98 	if (stat(dev, &statb) < 0) {
99 		printf("Can't stat %s: %s\n", dev, strerror(errno));
100 		return (0);
101 	}
102 	if (!forceimage && !S_ISCHR(statb.st_mode)) {
103 		pfatal("%s is not a character device", dev);
104 		if (reply("CONTINUE") == 0)
105 			return (0);
106 	}
107 	if ((fsreadfd = open(dev, O_RDONLY)) < 0) {
108 		printf("Can't open %s: %s\n", dev, strerror(errno));
109 		return (0);
110 	}
111 	if (preen == 0)
112 		printf("** %s", dev);
113 	if (nflag || (fswritefd = open(dev, O_WRONLY)) < 0) {
114 		fswritefd = -1;
115 		if (preen)
116 			pfatal("NO WRITE ACCESS");
117 		printf(" (NO WRITE)");
118 	}
119 	if (preen == 0)
120 		printf("\n");
121 	fsmodified = 0;
122 	lfdir = 0;
123 	initbarea(&sblk);
124 	initbarea(&asblk);
125 	sblk.b_un.b_buf = malloc(SBSIZE);
126 	sblock = malloc(SBSIZE);
127 	asblk.b_un.b_buf = malloc(SBSIZE);
128 	altsblock = malloc(SBSIZE);
129 	if (sblk.b_un.b_buf == NULL || asblk.b_un.b_buf == NULL ||
130 		sblock == NULL || altsblock == NULL)
131 		errx(EEXIT, "cannot allocate space for superblock");
132 	if (!forceimage && (lp = getdisklabel(NULL, fsreadfd)) != NULL)
133 		dev_bsize = secsize = lp->d_secsize;
134 	else
135 		dev_bsize = secsize = DEV_BSIZE;
136 	/*
137 	 * Read in the superblock, looking for alternates if necessary
138 	 */
139 	if (readsb(1) == 0) {
140 		if (bflag || preen || forceimage ||
141 		    calcsb(dev, fsreadfd, &proto) == 0)
142 			return(0);
143 		if (reply("LOOK FOR ALTERNATE SUPERBLOCKS") == 0)
144 			return (0);
145 		for (cg = 0; cg < proto.fs_ncg; cg++) {
146 			bflag = fsbtodb(&proto, cgsblock(&proto, cg));
147 			if (readsb(0) != 0)
148 				break;
149 		}
150 		if (cg >= proto.fs_ncg) {
151 			printf("%s %s\n%s %s\n%s %s\n",
152 				"SEARCH FOR ALTERNATE SUPER-BLOCK",
153 				"FAILED. YOU MUST USE THE",
154 				"-b OPTION TO fsck_ffs TO SPECIFY THE",
155 				"LOCATION OF AN ALTERNATE",
156 				"SUPER-BLOCK TO SUPPLY NEEDED",
157 				"INFORMATION; SEE fsck_ffs(8).");
158 			return(0);
159 		}
160 		doskipclean = 0;
161 		pwarn("USING ALTERNATE SUPERBLOCK AT %d\n", bflag);
162 	}
163 	if (debug)
164 		printf("clean = %d\n", sblock->fs_clean);
165 	if (doswap)
166 		doskipclean = 0;
167 	if (sblock->fs_clean & FS_ISCLEAN) {
168 		if (doskipclean) {
169 			pwarn("%sile system is clean; not checking\n",
170 			    preen ? "f" : "** F");
171 			return (-1);
172 		}
173 		if (!preen && !doswap)
174 			pwarn("** File system is already clean\n");
175 	}
176 	maxfsblock = sblock->fs_size;
177 	maxino = sblock->fs_ncg * sblock->fs_ipg;
178 	sizepb = sblock->fs_bsize;
179 	maxfilesize = sblock->fs_bsize * NDADDR - 1;
180 	for (i = 0; i < NIADDR; i++) {
181 		sizepb *= NINDIR(sblock);
182 		maxfilesize += sizepb;
183 	}
184 	/*
185 	 * Check and potentially fix certain fields in the super block.
186 	 */
187 	if (sblock->fs_optim != FS_OPTTIME && sblock->fs_optim != FS_OPTSPACE) {
188 		pfatal("UNDEFINED OPTIMIZATION IN SUPERBLOCK");
189 		if (reply("SET TO DEFAULT") == 1) {
190 			sblock->fs_optim = FS_OPTTIME;
191 			sbdirty();
192 		}
193 	}
194 	if ((sblock->fs_minfree < 0 || sblock->fs_minfree > 99)) {
195 		pfatal("IMPOSSIBLE MINFREE=%d IN SUPERBLOCK",
196 			sblock->fs_minfree);
197 		if (reply("SET TO DEFAULT") == 1) {
198 			sblock->fs_minfree = 10;
199 			sbdirty();
200 		}
201 	}
202 	if (sblock->fs_interleave < 1 ||
203 	    sblock->fs_interleave > sblock->fs_nsect) {
204 		pwarn("IMPOSSIBLE INTERLEAVE=%d IN SUPERBLOCK",
205 			sblock->fs_interleave);
206 		sblock->fs_interleave = 1;
207 		if (preen)
208 			printf(" (FIXED)\n");
209 		if (preen || reply("SET TO DEFAULT") == 1) {
210 			sbdirty();
211 			dirty(&asblk);
212 		}
213 	}
214 	if (sblock->fs_npsect < sblock->fs_nsect ||
215 	    sblock->fs_npsect > sblock->fs_nsect*2) {
216 		pwarn("IMPOSSIBLE NPSECT=%d IN SUPERBLOCK",
217 			sblock->fs_npsect);
218 		sblock->fs_npsect = sblock->fs_nsect;
219 		if (preen)
220 			printf(" (FIXED)\n");
221 		if (preen || reply("SET TO DEFAULT") == 1) {
222 			sbdirty();
223 			dirty(&asblk);
224 		}
225 	}
226 	if (sblock->fs_bmask != ~(sblock->fs_bsize - 1)) {
227 		pwarn("INCORRECT BMASK=0x%x IN SUPERBLOCK",
228 			sblock->fs_bmask);
229 		sblock->fs_bmask = ~(sblock->fs_bsize - 1);
230 		if (preen)
231 			printf(" (FIXED)\n");
232 		if (preen || reply("FIX") == 1) {
233 			sbdirty();
234 			dirty(&asblk);
235 		}
236 	}
237 	if (sblock->fs_fmask != ~(sblock->fs_fsize - 1)) {
238 		pwarn("INCORRECT FMASK=0x%x IN SUPERBLOCK",
239 			sblock->fs_fmask);
240 		sblock->fs_fmask = ~(sblock->fs_fsize - 1);
241 		if (preen)
242 			printf(" (FIXED)\n");
243 		if (preen || reply("FIX") == 1) {
244 			sbdirty();
245 			dirty(&asblk);
246 		}
247 	}
248 	if (sblock->fs_inodefmt >= FS_44INODEFMT) {
249 		if (sblock->fs_maxfilesize != maxfilesize) {
250 			pwarn("INCORRECT MAXFILESIZE=%lld IN SUPERBLOCK",
251 			    (unsigned long long)sblock->fs_maxfilesize);
252 			sblock->fs_maxfilesize = maxfilesize;
253 			if (preen)
254 				printf(" (FIXED)\n");
255 			if (preen || reply("FIX") == 1) {
256 				sbdirty();
257 				dirty(&asblk);
258 			}
259 		}
260 		if (sblock->fs_maxsymlinklen != MAXSYMLINKLEN) {
261 			pwarn("INCORRECT MAXSYMLINKLEN=%d IN SUPERBLOCK",
262 				sblock->fs_maxsymlinklen);
263 			sblock->fs_maxsymlinklen = MAXSYMLINKLEN;
264 			if (preen)
265 				printf(" (FIXED)\n");
266 			if (preen || reply("FIX") == 1) {
267 				sbdirty();
268 				dirty(&asblk);
269 			}
270 		}
271 		if (sblock->fs_qbmask != ~sblock->fs_bmask) {
272 			pwarn("INCORRECT QBMASK=%llx IN SUPERBLOCK",
273 			    (unsigned long long)sblock->fs_qbmask);
274 			sblock->fs_qbmask = ~sblock->fs_bmask;
275 			if (preen)
276 				printf(" (FIXED)\n");
277 			if (preen || reply("FIX") == 1) {
278 				sbdirty();
279 				dirty(&asblk);
280 			}
281 		}
282 		if (sblock->fs_qfmask != ~sblock->fs_fmask) {
283 			pwarn("INCORRECT QFMASK=%llx IN SUPERBLOCK",
284 			    (unsigned long long)sblock->fs_qfmask);
285 			sblock->fs_qfmask = ~sblock->fs_fmask;
286 			if (preen)
287 				printf(" (FIXED)\n");
288 			if (preen || reply("FIX") == 1) {
289 				sbdirty();
290 				dirty(&asblk);
291 			}
292 		}
293 		newinofmt = 1;
294 	} else {
295 		sblock->fs_qbmask = ~sblock->fs_bmask;
296 		sblock->fs_qfmask = ~sblock->fs_fmask;
297 		newinofmt = 0;
298 	}
299 	/*
300 	 * Convert to new inode format.
301 	 */
302 	if (cvtlevel >= 2 && sblock->fs_inodefmt < FS_44INODEFMT) {
303 		if (preen)
304 			pwarn("CONVERTING TO NEW INODE FORMAT\n");
305 		else if (!reply("CONVERT TO NEW INODE FORMAT"))
306 			return(0);
307 		doinglevel2++;
308 		sblock->fs_inodefmt = FS_44INODEFMT;
309 		sblock->fs_maxfilesize = maxfilesize;
310 		sblock->fs_maxsymlinklen = MAXSYMLINKLEN;
311 		sblock->fs_qbmask = ~sblock->fs_bmask;
312 		sblock->fs_qfmask = ~sblock->fs_fmask;
313 		sbdirty();
314 		dirty(&asblk);
315 	}
316 	/*
317 	 * Convert to new cylinder group format.
318 	 */
319 	if (cvtlevel >= 1 && sblock->fs_postblformat == FS_42POSTBLFMT) {
320 		if (preen)
321 			pwarn("CONVERTING TO NEW CYLINDER GROUP FORMAT\n");
322 		else if (!reply("CONVERT TO NEW CYLINDER GROUP FORMAT"))
323 			return(0);
324 		doinglevel1++;
325 		sblock->fs_postblformat = FS_DYNAMICPOSTBLFMT;
326 		sblock->fs_nrpos = 8;
327 		sblock->fs_postbloff =
328 		    (char *)(&sblock->fs_opostbl[0][0]) -
329 		    (char *)(&sblock->fs_firstfield);
330 		sblock->fs_rotbloff = &sblock->fs_space[0] -
331 		    (u_char *)(&sblock->fs_firstfield);
332 		sblock->fs_cgsize =
333 			fragroundup(sblock, CGSIZE(sblock));
334 		sbdirty();
335 		dirty(&asblk);
336 	}
337 	if (asblk.b_dirty && !bflag) {
338 		memmove((struct fs*)sblk.b_un.b_fs, sblock, SBSIZE);
339 		if (needswap)
340 			ffs_sb_swap(sblock, (struct fs*)sblk.b_un.b_fs);
341 		memmove(asblk.b_un.b_fs, sblk.b_un.b_fs, (size_t)sblock->fs_sbsize);
342 		flush(fswritefd, &asblk);
343 	}
344 	/*
345 	 * read in the summary info.
346 	 */
347 	asked = 0;
348 	sblock->fs_csp = (struct csum *)calloc(1, sblock->fs_cssize);
349 	for (i = 0, j = 0; i < sblock->fs_cssize; i += sblock->fs_bsize, j++) {
350 		size = sblock->fs_cssize - i < sblock->fs_bsize ?
351 		    sblock->fs_cssize - i : sblock->fs_bsize;
352 		ccsp = (struct csum *)((char *)sblock->fs_csp + i);
353 		if (bread(fsreadfd, (char *)ccsp,
354 		    fsbtodb(sblock, sblock->fs_csaddr + j * sblock->fs_frag),
355 		    size) != 0 && !asked) {
356 			pfatal("BAD SUMMARY INFORMATION");
357 			if (reply("CONTINUE") == 0) {
358 				markclean = 0;
359 				exit(EEXIT);
360 			}
361 			asked++;
362 		}
363 		if (doswap) {
364 			ffs_csum_swap(ccsp, ccsp, size);
365 			bwrite(fswritefd, (char *)ccsp,
366 			    fsbtodb(sblock,
367 				sblock->fs_csaddr + j * sblock->fs_frag),
368 			    size);
369 		}
370 		if (needswap)
371 			ffs_csum_swap(ccsp, ccsp, size);
372 	}
373 	/*
374 	 * allocate and initialize the necessary maps
375 	 */
376 	bmapsize = roundup(howmany(maxfsblock, NBBY), sizeof(int16_t));
377 	blockmap = calloc((unsigned)bmapsize, sizeof (char));
378 	if (blockmap == NULL) {
379 		printf("cannot alloc %u bytes for blockmap\n",
380 		    (unsigned)bmapsize);
381 		goto badsblabel;
382 	}
383 	statemap = calloc((unsigned)(maxino + 1), sizeof(char));
384 	if (statemap == NULL) {
385 		printf("cannot alloc %u bytes for statemap\n",
386 		    (unsigned)(maxino + 1));
387 		goto badsblabel;
388 	}
389 	typemap = calloc((unsigned)(maxino + 1), sizeof(char));
390 	if (typemap == NULL) {
391 		printf("cannot alloc %u bytes for typemap\n",
392 		    (unsigned)(maxino + 1));
393 		goto badsblabel;
394 	}
395 	lncntp = (int16_t *)calloc((unsigned)(maxino + 1), sizeof(int16_t));
396 	if (lncntp == NULL) {
397 		printf("cannot alloc %u bytes for lncntp\n",
398 		    (unsigned)((maxino + 1) * sizeof(int16_t)));
399 		goto badsblabel;
400 	}
401 	/*
402 	 * cs_ndir may be inaccurate, particularly if we're using the -b
403 	 * option, so set a minimum to prevent bogus subdirectory reconnects
404 	 * and really inefficient directory scans.
405 	 * Also set a maximum in case the value is too large.
406 	 */
407 	numdirs = sblock->fs_cstotal.cs_ndir;
408 	if (numdirs < 1024)
409 		numdirs = 1024;
410 	if (numdirs > maxino + 1)
411 		numdirs = maxino + 1;
412 	inplast = 0;
413 	listmax = numdirs + 10;
414 	inpsort = (struct inoinfo **)calloc((unsigned)listmax,
415 	    sizeof(struct inoinfo *));
416 	inphead = (struct inoinfo **)calloc((unsigned)numdirs,
417 	    sizeof(struct inoinfo *));
418 	if (inpsort == NULL || inphead == NULL) {
419 		printf("cannot alloc %u bytes for inphead\n",
420 		    (unsigned)(numdirs * sizeof(struct inoinfo *)));
421 		goto badsblabel;
422 	}
423 	cgrp = malloc(sblock->fs_cgsize);
424 	if (cgrp == NULL) {
425 		printf("cannot alloc %u bytes for cylinder group\n",
426 		    sblock->fs_cgsize);
427 		goto badsblabel;
428 	}
429 	bufinit();
430 	if (sblock->fs_flags & FS_DOSOFTDEP)
431 		usedsoftdep = 1;
432 	else
433 		usedsoftdep = 0;
434 	return (1);
435 
436 badsblabel:
437 	markclean=0;
438 	ckfini();
439 	return (0);
440 }
441 
442 /*
443  * Read in the super block and its summary info.
444  */
445 static int
446 readsb(listerr)
447 	int listerr;
448 {
449 	ufs_daddr_t super = bflag ? bflag : SBOFF / dev_bsize;
450 	struct fs *fs;
451 
452 	if (bread(fsreadfd, (char *)sblk.b_un.b_fs, super, (long)SBSIZE) != 0)
453 		return (0);
454 	sblk.b_bno = super;
455 	sblk.b_size = SBSIZE;
456 
457 	fs = sblk.b_un.b_fs;
458 	/* auto detect byte order */
459 	if( fs->fs_magic == FS_MAGIC) {
460 			if (endian == 0 || BYTE_ORDER == endian) {
461 				needswap = 0;
462 				doswap = do_blkswap = do_dirswap = 0;
463 			} else {
464 				needswap = 1;
465 				doswap = do_blkswap = do_dirswap = 1;
466 			}
467 	} else if (fs->fs_magic == bswap32(FS_MAGIC)) {
468 		if (endian == 0 || BYTE_ORDER != endian) {
469 			needswap = 1;
470 			doswap = do_blkswap = do_dirswap = 0;
471 		} else {
472 			needswap = 0;
473 			doswap = do_blkswap = do_dirswap = 1;
474 		}
475 	} else {
476 		badsb(listerr, "MAGIC NUMBER WRONG");
477 		return (0);
478 	}
479 	if (doswap) {
480 		if (preen)
481 			errx(EEXIT, "incompatible options -B and -p");
482 		if (nflag)
483 			errx(EEXIT, "incompatible options -B and -n");
484 		if (endian == LITTLE_ENDIAN) {
485 			if (!reply("CONVERT TO LITTLE ENDIAN"))
486 				return 0;
487 		} else if (endian == BIG_ENDIAN) {
488 			if (!reply("CONVERT TO BIG ENDIAN"))
489 				return 0;
490 		} else
491 			pfatal("INTERNAL ERROR: unknown endian");
492 	}
493 	if (needswap)
494 		printf("** Swapped byte order\n");
495 	/* swap SB byte order if asked */
496 	if (doswap)
497 		ffs_sb_swap(sblk.b_un.b_fs, sblk.b_un.b_fs);
498 
499 	memmove(sblock, sblk.b_un.b_fs, SBSIZE);
500 	if (needswap)
501 		ffs_sb_swap(sblk.b_un.b_fs, sblock);
502 
503 	/*
504 	 * run a few consistency checks of the super block
505 	 */
506 	if (sblock->fs_ncg < 1)
507 		{ badsb(listerr, "NCG OUT OF RANGE"); return (0); }
508 	if (sblock->fs_cpg < 1)
509 		{ badsb(listerr, "CPG OUT OF RANGE"); return (0); }
510 	if (sblock->fs_ncg * sblock->fs_cpg < sblock->fs_ncyl ||
511 	    (sblock->fs_ncg - 1) * sblock->fs_cpg >= sblock->fs_ncyl)
512 		{ badsb(listerr, "NCYL LESS THAN NCG*CPG"); return (0); }
513 	if (sblock->fs_sbsize > SBSIZE)
514 		{ badsb(listerr, "SIZE PREPOSTEROUSLY LARGE"); return (0); }
515 	/*
516 	 * Compute block size that the filesystem is based on,
517 	 * according to fsbtodb, and adjust superblock block number
518 	 * so we can tell if this is an alternate later.
519 	 */
520 	super *= dev_bsize;
521 	dev_bsize = sblock->fs_fsize / fsbtodb(sblock, 1);
522 	sblk.b_bno = super / dev_bsize;
523 
524 	if (bflag) {
525 		havesb = 1;
526 		return (1);
527 	}
528 	/*
529 	 * Set all possible fields that could differ, then do check
530 	 * of whole super block against an alternate super block.
531 	 * When an alternate super-block is specified this check is skipped.
532 	 */
533 	getblk(&asblk, cgsblock(sblock, sblock->fs_ncg - 1), sblock->fs_sbsize);
534 	if (asblk.b_errs)
535 		return (0);
536 	/* swap SB byte order if asked */
537 	if (doswap)
538 		ffs_sb_swap(asblk.b_un.b_fs, asblk.b_un.b_fs);
539 
540 	memmove(altsblock, asblk.b_un.b_fs, sblock->fs_sbsize);
541 	if (needswap)
542 		ffs_sb_swap(asblk.b_un.b_fs, altsblock);
543 	if (cmpsblks(sblock, altsblock)) {
544 		if (debug) {
545 			long *nlp, *olp, *endlp;
546 
547 			printf("superblock mismatches\n");
548 			nlp = (long *)altsblock;
549 			olp = (long *)sblock;
550 			endlp = olp + (sblock->fs_sbsize / sizeof *olp);
551 			for ( ; olp < endlp; olp++, nlp++) {
552 				if (*olp == *nlp)
553 					continue;
554 				printf("offset %ld, original %lx, alternate %lx\n",
555 				    (long)(olp - (long *)sblock), *olp, *nlp);
556 			}
557 		}
558 		badsb(listerr,
559 		"VALUES IN SUPER BLOCK DISAGREE WITH THOSE IN FIRST ALTERNATE");
560 		return (0);
561 	}
562 	/* Now we know the SB is valid, we can write it back if needed */
563 	if (doswap) {
564 		sbdirty();
565 		dirty(&asblk);
566 	}
567 	havesb = 1;
568 	return (1);
569 }
570 
571 int
572 cmpsblks(const struct fs *sb, struct fs *asb)
573 {
574 
575 	/*
576 	 * Copy fields which we don't care if they're different in the
577 	 * alternate superblocks, as they're either likely to be
578 	 * different because they're per-cylinder-group specific, or
579 	 * because they're transient details which are only maintained
580 	 * in the primary superblock.
581 	 */
582 	asb->fs_firstfield = sb->fs_firstfield;
583 	asb->fs_unused_1 = sb->fs_unused_1;
584 	asb->fs_time = sb->fs_time;
585 	asb->fs_cstotal = sb->fs_cstotal;
586 	asb->fs_cgrotor = sb->fs_cgrotor;
587 	asb->fs_fmod = sb->fs_fmod;
588 	asb->fs_clean = sb->fs_clean;
589 	asb->fs_ronly = sb->fs_ronly;
590 	asb->fs_flags = sb->fs_flags;
591 	asb->fs_maxcontig = sb->fs_maxcontig;
592 	asb->fs_minfree = sb->fs_minfree;
593 	asb->fs_optim = sb->fs_optim;
594 	asb->fs_rotdelay = sb->fs_rotdelay;
595 	asb->fs_maxbpg = sb->fs_maxbpg;
596 	memmove(asb->fs_ocsp, sb->fs_ocsp, sizeof sb->fs_ocsp);
597 	asb->fs_contigdirs = sb->fs_contigdirs;
598 	asb->fs_csp = sb->fs_csp;
599 	asb->fs_maxcluster = sb->fs_maxcluster;
600 	memmove(asb->fs_fsmnt, sb->fs_fsmnt, sizeof sb->fs_fsmnt);
601 	memmove(asb->fs_snapinum,
602 		sb->fs_snapinum, sizeof sb->fs_snapinum);
603 	asb->fs_avgfilesize = sb->fs_avgfilesize;
604 	asb->fs_avgfpdir = sb->fs_avgfpdir;
605 	asb->fs_pendingblocks = sb->fs_pendingblocks;
606 	asb->fs_pendinginodes = sb->fs_pendinginodes;
607 	memmove(asb->fs_sparecon,
608 		sb->fs_sparecon, sizeof sb->fs_sparecon);
609 	/*
610 	 * The following should not have to be copied, but need to be.
611 	 */
612 	asb->fs_fsbtodb = sb->fs_fsbtodb;
613 	asb->fs_interleave = sb->fs_interleave;
614 	asb->fs_npsect = sb->fs_npsect;
615 	asb->fs_nrpos = sb->fs_nrpos;
616 	asb->fs_qbmask = sb->fs_qbmask;
617 	asb->fs_qfmask = sb->fs_qfmask;
618 	asb->fs_state = sb->fs_state;
619 	asb->fs_maxfilesize = sb->fs_maxfilesize;
620 
621 	/*
622 	 * Compare the superblocks, effectively checking every other
623 	 * field to see if they differ.
624 	 */
625 	return (memcmp(sb, asb, (int)sb->fs_sbsize));
626 }
627 
628 static void
629 badsb(listerr, s)
630 	int listerr;
631 	char *s;
632 {
633 
634 	if (!listerr)
635 		return;
636 	if (preen)
637 		printf("%s: ", cdevname());
638 	pfatal("BAD SUPER BLOCK: %s\n", s);
639 }
640 
641 /*
642  * Calculate a prototype superblock based on information in the disk label.
643  * When done the cgsblock macro can be calculated and the fs_ncg field
644  * can be used. Do NOT attempt to use other macros without verifying that
645  * their needed information is available!
646  */
647 static int
648 calcsb(dev, devfd, fs)
649 	const char *dev;
650 	int devfd;
651 	struct fs *fs;
652 {
653 	struct disklabel *lp;
654 	struct partition *pp;
655 	char *cp;
656 	int i;
657 
658 	cp = strchr(dev, '\0') - 1;
659 	if ((cp == (char *)-1 || (*cp < 'a' || *cp > 'p')) && !isdigit(*cp)) {
660 		pfatal("%s: CANNOT FIGURE OUT FILE SYSTEM PARTITION\n", dev);
661 		return (0);
662 	}
663 	lp = getdisklabel(dev, devfd);
664 	if (isdigit(*cp))
665 		pp = &lp->d_partitions[0];
666 	else
667 		pp = &lp->d_partitions[*cp - 'a'];
668 	if (pp->p_fstype != FS_BSDFFS) {
669 		pfatal("%s: NOT LABELED AS A BSD FILE SYSTEM (%s)\n",
670 			dev, pp->p_fstype < FSMAXTYPES ?
671 			fstypenames[pp->p_fstype] : "unknown");
672 		return (0);
673 	}
674 	/* avoid divide by 0 */
675 	if (pp->p_fsize == 0 || pp->p_frag == 0)
676 		return (0);
677 	memset(fs, 0, sizeof(struct fs));
678 	fs->fs_fsize = pp->p_fsize;
679 	fs->fs_frag = pp->p_frag;
680 	fs->fs_cpg = pp->p_cpg;
681 	fs->fs_size = pp->p_size;
682 	fs->fs_ntrak = lp->d_ntracks;
683 	fs->fs_nsect = lp->d_nsectors;
684 	fs->fs_spc = lp->d_secpercyl;
685 	fs->fs_nspf = fs->fs_fsize / lp->d_secsize;
686 	fs->fs_sblkno = roundup(
687 		howmany(lp->d_bbsize + lp->d_sbsize, fs->fs_fsize),
688 		fs->fs_frag);
689 	fs->fs_cgmask = 0xffffffff;
690 	for (i = fs->fs_ntrak; i > 1; i >>= 1)
691 		fs->fs_cgmask <<= 1;
692 	if (!POWEROF2(fs->fs_ntrak))
693 		fs->fs_cgmask <<= 1;
694 	fs->fs_cgoffset = roundup(
695 		howmany(fs->fs_nsect, NSPF(fs)), fs->fs_frag);
696 	fs->fs_fpg = (fs->fs_cpg * fs->fs_spc) / NSPF(fs);
697 	fs->fs_ncg = howmany(fs->fs_size / fs->fs_spc, fs->fs_cpg);
698 	for (fs->fs_fsbtodb = 0, i = NSPF(fs); i > 1; i >>= 1)
699 		fs->fs_fsbtodb++;
700 	dev_bsize = lp->d_secsize;
701 	return (1);
702 }
703 
704 static struct disklabel *
705 getdisklabel(s, fd)
706 	const char *s;
707 	int	fd;
708 {
709 	static struct disklabel lab;
710 
711 	if (ioctl(fd, DIOCGDINFO, (char *)&lab) < 0) {
712 		if (s == NULL)
713 			return ((struct disklabel *)NULL);
714 		pwarn("ioctl (GCINFO): %s\n", strerror(errno));
715 		errx(EEXIT, "%s: can't read disk label", s);
716 	}
717 	return (&lab);
718 }
719