xref: /minix3/sbin/fsck_ext2fs/setup.c (revision f14fb602092e015ff630df58e17c2a9cd57d29b3)
1 /*	$NetBSD: setup.c,v 1.28 2011/09/16 16:13:18 plunky 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. Neither the name of the University nor the names of its contributors
16  *	may be used to endorse or promote products derived from this software
17  *	without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1997 Manuel Bouyer.
34  *
35  * Redistribution and use in source and binary forms, with or without
36  * modification, are permitted provided that the following conditions
37  * are met:
38  * 1. Redistributions of source code must retain the above copyright
39  *	notice, this list of conditions and the following disclaimer.
40  * 2. Redistributions in binary form must reproduce the above copyright
41  *	notice, this list of conditions and the following disclaimer in the
42  *	documentation and/or other materials provided with the distribution.
43  *
44  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
45  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
46  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
47  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
48  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
49  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
50  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
51  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
52  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
53  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
54  */
55 
56 #include <sys/cdefs.h>
57 #ifndef lint
58 #if 0
59 static char sccsid[] = "@(#)setup.c	8.5 (Berkeley) 11/23/94";
60 #else
61 __RCSID("$NetBSD: setup.c,v 1.28 2011/09/16 16:13:18 plunky Exp $");
62 #endif
63 #endif /* not lint */
64 
65 #define FSTYPENAMES
66 #include <sys/param.h>
67 #include <sys/time.h>
68 #include <ufs/ext2fs/ext2fs_dinode.h>
69 #include <ufs/ext2fs/ext2fs.h>
70 #include <sys/stat.h>
71 #include <sys/ioctl.h>
72 #include <sys/disklabel.h>
73 #include <sys/file.h>
74 
75 #include <errno.h>
76 #include <stdio.h>
77 #include <stdlib.h>
78 #include <string.h>
79 #include <ctype.h>
80 
81 #include "fsck.h"
82 #include "extern.h"
83 #include "fsutil.h"
84 #include "exitvalues.h"
85 
86 void badsb(int, const char *);
87 int calcsb(const char *, int, struct m_ext2fs *);
88 static struct disklabel *getdisklabel(const char *, int);
89 static int readsb(int);
90 
91 int
92 setup(const char *dev)
93 {
94 	long cg, asked, i;
95 	long bmapsize;
96 	struct disklabel *lp;
97 #ifndef __minix
98 	off_t sizepb;
99 #else
100 	u64_t sizepb;
101 #endif
102 	struct stat statb;
103 	struct m_ext2fs proto;
104 	int doskipclean;
105 	u_int64_t maxfilesize;
106 
107 	havesb = 0;
108 	fswritefd = -1;
109 	doskipclean = skipclean;
110 	if (stat(dev, &statb) < 0) {
111 		printf("Can't stat %s: %s\n", dev, strerror(errno));
112 		return 0;
113 	}
114 
115 #ifndef __minix
116 	if (!S_ISCHR(statb.st_mode)) {
117 		pfatal("%s is not a character device", dev);
118 		if (reply("CONTINUE") == 0)
119 			return 0;
120 	}
121 #endif
122 
123 	if ((fsreadfd = open(dev, O_RDONLY)) < 0) {
124 		printf("Can't open %s: %s\n", dev, strerror(errno));
125 		return 0;
126 	}
127 	if (preen == 0)
128 		printf("** %s", dev);
129 	if (nflag || (fswritefd = open(dev, O_WRONLY)) < 0) {
130 		fswritefd = -1;
131 		if (preen)
132 			pfatal("NO WRITE ACCESS");
133 		printf(" (NO WRITE)");
134 	}
135 	if (preen == 0)
136 		printf("\n");
137 	fsmodified = 0;
138 	lfdir = 0;
139 	initbarea(&sblk);
140 	initbarea(&asblk);
141 	sblk.b_un.b_buf = malloc(SBSIZE);
142 	asblk.b_un.b_buf = malloc(SBSIZE);
143 	if (sblk.b_un.b_buf == NULL || asblk.b_un.b_buf == NULL)
144 		errexit("cannot allocate space for superblock");
145 	if ((lp = getdisklabel(NULL, fsreadfd)) != NULL)
146 		dev_bsize = secsize = lp->d_secsize;
147 	else
148 		dev_bsize = secsize = DEV_BSIZE;
149 	/*
150 	 * Read in the superblock, looking for alternates if necessary
151 	 */
152 	if (readsb(1) == 0) {
153 		if (bflag || preen || calcsb(dev, fsreadfd, &proto) == 0)
154 			return 0;
155 		if (reply("LOOK FOR ALTERNATE SUPERBLOCKS") == 0)
156 			return 0;
157 		for (cg = 1; cg < proto.e2fs_ncg; cg++) {
158 			bflag = fsbtodb(&proto,
159 			    cg * proto.e2fs.e2fs_bpg +
160 			    proto.e2fs.e2fs_first_dblock);
161 			if (readsb(0) != 0)
162 				break;
163 		}
164 		if (cg >= proto.e2fs_ncg) {
165 			printf("%s %s\n%s %s\n%s %s\n",
166 			    "SEARCH FOR ALTERNATE SUPER-BLOCK",
167 			    "FAILED. YOU MUST USE THE",
168 			    "-b OPTION TO FSCK_FFS TO SPECIFY THE",
169 			    "LOCATION OF AN ALTERNATE",
170 			    "SUPER-BLOCK TO SUPPLY NEEDED",
171 			    "INFORMATION; SEE fsck_ext2fs(8).");
172 			return 0;
173 		}
174 		doskipclean = 0;
175 		pwarn("USING ALTERNATE SUPERBLOCK AT %d\n", bflag);
176 	}
177 	if (debug)
178 		printf("state = %d\n", sblock.e2fs.e2fs_state);
179 	if (sblock.e2fs.e2fs_state == E2FS_ISCLEAN) {
180 		if (doskipclean) {
181 			pwarn("%sile system is clean; not checking\n",
182 			    preen ? "f" : "** F");
183 			return -1;
184 		}
185 		if (!preen)
186 			pwarn("** File system is already clean\n");
187 	}
188 	maxfsblock = sblock.e2fs.e2fs_bcount;
189 	maxino = sblock.e2fs_ncg * sblock.e2fs.e2fs_ipg;
190 	sizepb = sblock.e2fs_bsize;
191 	maxfilesize = sblock.e2fs_bsize * NDADDR - 1;
192 	for (i = 0; i < NIADDR; i++) {
193 		sizepb *= NINDIR(&sblock);
194 		maxfilesize += sizepb;
195 	}
196 	/*
197 	 * Check and potentially fix certain fields in the super block.
198 	 */
199 	if (/* (sblock.e2fs.e2fs_rbcount < 0) || */
200 	    (sblock.e2fs.e2fs_rbcount > sblock.e2fs.e2fs_bcount)) {
201 		pfatal("IMPOSSIBLE RESERVED BLOCK COUNT=%d IN SUPERBLOCK",
202 		    sblock.e2fs.e2fs_rbcount);
203 		if (reply("SET TO DEFAULT") == 1) {
204 			sblock.e2fs.e2fs_rbcount =
205 			    sblock.e2fs.e2fs_bcount * MINFREE / 100;
206 			sbdirty();
207 			dirty(&asblk);
208 		}
209 	}
210 	if (sblock.e2fs.e2fs_bpg != sblock.e2fs.e2fs_fpg) {
211 		pfatal("WRONG FPG=%d (BPG=%d) IN SUPERBLOCK",
212 		    sblock.e2fs.e2fs_fpg, sblock.e2fs.e2fs_bpg);
213 		return 0;
214 	}
215 	if (asblk.b_dirty && !bflag) {
216 		copyback_sb(&asblk);
217 		flush(fswritefd, &asblk);
218 	}
219 	/*
220 	 * read in the summary info.
221 	 */
222 
223 	sblock.e2fs_gd = malloc(sblock.e2fs_ngdb * sblock.e2fs_bsize);
224 	if (sblock.e2fs_gd == NULL)
225 		errexit("out of memory");
226 	asked = 0;
227 	for (i = 0; i < sblock.e2fs_ngdb; i++) {
228 		if (bread(fsreadfd,
229 		    (char *)&sblock.e2fs_gd[i * sblock.e2fs_bsize /
230 		    sizeof(struct ext2_gd)],
231 		    fsbtodb(&sblock, ((sblock.e2fs_bsize > 1024) ? 0 : 1) +
232 		    i + 1),
233 		    sblock.e2fs_bsize) != 0 && !asked) {
234 			pfatal("BAD SUMMARY INFORMATION");
235 			if (reply("CONTINUE") == 0)
236 				exit(FSCK_EXIT_CHECK_FAILED);
237 			asked++;
238 		}
239 	}
240 	/*
241 	 * allocate and initialize the necessary maps
242 	 */
243 	bmapsize = roundup(howmany(maxfsblock, NBBY), sizeof(int16_t));
244 	blockmap = calloc((unsigned int)bmapsize, sizeof(char));
245 	if (blockmap == NULL) {
246 		printf("cannot alloc %u bytes for blockmap\n",
247 		    (unsigned int)bmapsize);
248 		goto badsblabel;
249 	}
250 	statemap = calloc((unsigned int)(maxino + 2), sizeof(char));
251 	if (statemap == NULL) {
252 		printf("cannot alloc %u bytes for statemap\n",
253 		    (unsigned int)(maxino + 1));
254 		goto badsblabel;
255 	}
256 	typemap = calloc((unsigned int)(maxino + 1), sizeof(char));
257 	if (typemap == NULL) {
258 		printf("cannot alloc %u bytes for typemap\n",
259 		    (unsigned int)(maxino + 1));
260 		goto badsblabel;
261 	}
262 	lncntp = calloc((unsigned)(maxino + 1), sizeof(int16_t));
263 	if (lncntp == NULL) {
264 		printf("cannot alloc %u bytes for lncntp\n",
265 		    (unsigned int)((maxino + 1) * sizeof(int16_t)));
266 		goto badsblabel;
267 	}
268 	for (numdirs = 0, cg = 0; cg < sblock.e2fs_ncg; cg++) {
269 		numdirs += fs2h16(sblock.e2fs_gd[cg].ext2bgd_ndirs);
270 	}
271 	inplast = 0;
272 	listmax = numdirs + 10;
273 	inpsort = calloc((unsigned int)listmax, sizeof(struct inoinfo *));
274 	inphead = calloc((unsigned int)numdirs, sizeof(struct inoinfo *));
275 	if (inpsort == NULL || inphead == NULL) {
276 		printf("cannot alloc %u bytes for inphead\n",
277 		    (unsigned int)(numdirs * sizeof(struct inoinfo *)));
278 		goto badsblabel;
279 	}
280 	bufinit();
281 	return 1;
282 
283 badsblabel:
284 	ckfini(0);
285 	return 0;
286 }
287 
288 /*
289  * Read in the super block and its summary info, convert to host byte order.
290  */
291 static int
292 readsb(int listerr)
293 {
294 	daddr_t super = bflag ? bflag : SBOFF / dev_bsize;
295 
296 	if (bread(fsreadfd, (char *)sblk.b_un.b_fs, super, (long)SBSIZE) != 0)
297 		return 0;
298 	sblk.b_bno = super;
299 	sblk.b_size = SBSIZE;
300 
301 	/* Copy the superblock in memory */
302 	e2fs_sbload(sblk.b_un.b_fs, &sblock.e2fs);
303 
304 	/*
305 	 * run a few consistency checks of the super block
306 	 */
307 	if (sblock.e2fs.e2fs_magic != E2FS_MAGIC) {
308 		badsb(listerr, "MAGIC NUMBER WRONG");
309 		return 0;
310 	}
311 	if (sblock.e2fs.e2fs_log_bsize > 2) {
312 		badsb(listerr, "BAD LOG_BSIZE");
313 		return 0;
314 	}
315 	if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
316 	    (!powerof2(sblock.e2fs.e2fs_inode_size) ||
317 	     sblock.e2fs.e2fs_inode_size < sizeof(struct ext2fs_dinode) ||
318 	     sblock.e2fs.e2fs_inode_size >
319 	      (1024 << sblock.e2fs.e2fs_log_bsize))) {
320 		badsb(listerr, "BAD INODE_SIZE");
321 		return 0;
322 	}
323 
324 	/* compute the dynamic fields of the in-memory sb */
325 	/* compute dynamic sb infos */
326 	sblock.e2fs_ncg =
327 	    howmany(sblock.e2fs.e2fs_bcount - sblock.e2fs.e2fs_first_dblock,
328 	    sblock.e2fs.e2fs_bpg);
329 	/* XXX assume hw bsize = 512 */
330 	sblock.e2fs_fsbtodb = sblock.e2fs.e2fs_log_bsize + 1;
331 	sblock.e2fs_bsize = 1024 << sblock.e2fs.e2fs_log_bsize;
332 	sblock.e2fs_bshift = LOG_MINBSIZE + sblock.e2fs.e2fs_log_bsize;
333 	sblock.e2fs_qbmask = sblock.e2fs_bsize - 1;
334 	sblock.e2fs_bmask = ~sblock.e2fs_qbmask;
335 	sblock.e2fs_ngdb = howmany(sblock.e2fs_ncg,
336 	    sblock.e2fs_bsize / sizeof(struct ext2_gd));
337 	sblock.e2fs_ipb = sblock.e2fs_bsize / EXT2_DINODE_SIZE(&sblock);
338 	sblock.e2fs_itpg = howmany(sblock.e2fs.e2fs_ipg, sblock.e2fs_ipb);
339 
340 	/*
341 	 * Compute block size that the filesystem is based on,
342 	 * according to fsbtodb, and adjust superblock block number
343 	 * so we can tell if this is an alternate later.
344 	 */
345 	super *= dev_bsize;
346 	dev_bsize = sblock.e2fs_bsize / fsbtodb(&sblock, 1);
347 	sblk.b_bno = super / dev_bsize;
348 
349 	if (sblock.e2fs_ncg == 1) {
350 		/* no alternate superblock; assume it's okay */
351 		havesb = 1;
352 		return 1;
353 	}
354 	getblk(&asblk, 1 * sblock.e2fs.e2fs_bpg + sblock.e2fs.e2fs_first_dblock,
355 		(long)SBSIZE);
356 	if (asblk.b_errs)
357 		return 0;
358 	if (bflag) {
359 		havesb = 1;
360 		return 1;
361 	}
362 
363 	/*
364 	 * Set all possible fields that could differ, then do check
365 	 * of whole super block against an alternate super block.
366 	 * When an alternate super-block is specified this check is skipped.
367 	 */
368 	asblk.b_un.b_fs->e2fs_rbcount = sblk.b_un.b_fs->e2fs_rbcount;
369 	asblk.b_un.b_fs->e2fs_fbcount = sblk.b_un.b_fs->e2fs_fbcount;
370 	asblk.b_un.b_fs->e2fs_ficount = sblk.b_un.b_fs->e2fs_ficount;
371 	asblk.b_un.b_fs->e2fs_mtime = sblk.b_un.b_fs->e2fs_mtime;
372 	asblk.b_un.b_fs->e2fs_wtime = sblk.b_un.b_fs->e2fs_wtime;
373 	asblk.b_un.b_fs->e2fs_mnt_count = sblk.b_un.b_fs->e2fs_mnt_count;
374 	asblk.b_un.b_fs->e2fs_max_mnt_count =
375 	    sblk.b_un.b_fs->e2fs_max_mnt_count;
376 	asblk.b_un.b_fs->e2fs_state = sblk.b_un.b_fs->e2fs_state;
377 	asblk.b_un.b_fs->e2fs_beh = sblk.b_un.b_fs->e2fs_beh;
378 	asblk.b_un.b_fs->e2fs_lastfsck = sblk.b_un.b_fs->e2fs_lastfsck;
379 	asblk.b_un.b_fs->e2fs_fsckintv = sblk.b_un.b_fs->e2fs_fsckintv;
380 	asblk.b_un.b_fs->e2fs_ruid = sblk.b_un.b_fs->e2fs_ruid;
381 	asblk.b_un.b_fs->e2fs_rgid = sblk.b_un.b_fs->e2fs_rgid;
382 	asblk.b_un.b_fs->e2fs_block_group_nr =
383 	    sblk.b_un.b_fs->e2fs_block_group_nr;
384 	asblk.b_un.b_fs->e2fs_features_rocompat &= ~EXT2F_ROCOMPAT_LARGEFILE;
385 	asblk.b_un.b_fs->e2fs_features_rocompat |=
386 	    sblk.b_un.b_fs->e2fs_features_rocompat & EXT2F_ROCOMPAT_LARGEFILE;
387 	if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
388 	    ((sblock.e2fs.e2fs_features_incompat & ~EXT2F_INCOMPAT_SUPP) ||
389 	    (sblock.e2fs.e2fs_features_rocompat & ~EXT2F_ROCOMPAT_SUPP))) {
390 		if (debug) {
391 			printf("compat 0x%08x, incompat 0x%08x, compat_ro "
392 			    "0x%08x\n",
393 			    sblock.e2fs.e2fs_features_compat,
394 			    sblock.e2fs.e2fs_features_incompat,
395 			    sblock.e2fs.e2fs_features_rocompat);
396 		}
397 		badsb(listerr, "INCOMPATIBLE FEATURE BITS IN SUPER BLOCK");
398 		return 0;
399 	}
400 	if (memcmp(sblk.b_un.b_fs, asblk.b_un.b_fs, SBSIZE)) {
401 		if (debug) {
402 			u_int32_t *nlp, *olp, *endlp;
403 
404 			printf("superblock mismatches\n");
405 			nlp = (u_int32_t *)asblk.b_un.b_fs;
406 			olp = (u_int32_t *)sblk.b_un.b_fs;
407 			endlp = olp + (SBSIZE / sizeof(*olp));
408 			for ( ; olp < endlp; olp++, nlp++) {
409 				if (*olp == *nlp)
410 					continue;
411 				printf("offset %ld, original %ld, "
412 				    "alternate %ld\n",
413 				    (long)(olp - (u_int32_t *)sblk.b_un.b_fs),
414 				    (long)fs2h32(*olp),
415 				    (long)fs2h32(*nlp));
416 			}
417 		}
418 		badsb(listerr,
419 		    "VALUES IN SUPER BLOCK DISAGREE WITH "
420 		    "THOSE IN FIRST ALTERNATE");
421 		return 0;
422 	}
423 	havesb = 1;
424 	return 1;
425 }
426 
427 void
428 copyback_sb(struct bufarea *bp)
429 {
430 	/* Copy the in-memory superblock back to buffer */
431 	bp->b_un.b_fs->e2fs_icount = h2fs32(sblock.e2fs.e2fs_icount);
432 	bp->b_un.b_fs->e2fs_bcount = h2fs32(sblock.e2fs.e2fs_bcount);
433 	bp->b_un.b_fs->e2fs_rbcount = h2fs32(sblock.e2fs.e2fs_rbcount);
434 	bp->b_un.b_fs->e2fs_fbcount = h2fs32(sblock.e2fs.e2fs_fbcount);
435 	bp->b_un.b_fs->e2fs_ficount = h2fs32(sblock.e2fs.e2fs_ficount);
436 	bp->b_un.b_fs->e2fs_first_dblock =
437 	    h2fs32(sblock.e2fs.e2fs_first_dblock);
438 	bp->b_un.b_fs->e2fs_log_bsize = h2fs32(sblock.e2fs.e2fs_log_bsize);
439 	bp->b_un.b_fs->e2fs_fsize = h2fs32(sblock.e2fs.e2fs_fsize);
440 	bp->b_un.b_fs->e2fs_bpg = h2fs32(sblock.e2fs.e2fs_bpg);
441 	bp->b_un.b_fs->e2fs_fpg = h2fs32(sblock.e2fs.e2fs_fpg);
442 	bp->b_un.b_fs->e2fs_ipg = h2fs32(sblock.e2fs.e2fs_ipg);
443 	bp->b_un.b_fs->e2fs_mtime = h2fs32(sblock.e2fs.e2fs_mtime);
444 	bp->b_un.b_fs->e2fs_wtime = h2fs32(sblock.e2fs.e2fs_wtime);
445 	bp->b_un.b_fs->e2fs_lastfsck = h2fs32(sblock.e2fs.e2fs_lastfsck);
446 	bp->b_un.b_fs->e2fs_fsckintv = h2fs32(sblock.e2fs.e2fs_fsckintv);
447 	bp->b_un.b_fs->e2fs_creator = h2fs32(sblock.e2fs.e2fs_creator);
448 	bp->b_un.b_fs->e2fs_rev = h2fs32(sblock.e2fs.e2fs_rev);
449 	bp->b_un.b_fs->e2fs_mnt_count = h2fs16(sblock.e2fs.e2fs_mnt_count);
450 	bp->b_un.b_fs->e2fs_max_mnt_count =
451 	    h2fs16(sblock.e2fs.e2fs_max_mnt_count);
452 	bp->b_un.b_fs->e2fs_magic = h2fs16(sblock.e2fs.e2fs_magic);
453 	bp->b_un.b_fs->e2fs_state = h2fs16(sblock.e2fs.e2fs_state);
454 	bp->b_un.b_fs->e2fs_beh = h2fs16(sblock.e2fs.e2fs_beh);
455 	bp->b_un.b_fs->e2fs_ruid = h2fs16(sblock.e2fs.e2fs_ruid);
456 	bp->b_un.b_fs->e2fs_rgid = h2fs16(sblock.e2fs.e2fs_rgid);
457 }
458 
459 void
460 badsb(int listerr, const char *s)
461 {
462 
463 	if (!listerr)
464 		return;
465 	if (preen)
466 		printf("%s: ", cdevname());
467 	pfatal("BAD SUPER BLOCK: %s\n", s);
468 }
469 
470 /*
471  * Calculate a prototype superblock based on information in the disk label.
472  * When done the cgsblock macro can be calculated and the fs_ncg field
473  * can be used. Do NOT attempt to use other macros without verifying that
474  * their needed information is available!
475  */
476 
477 int
478 calcsb(const char *dev, int devfd, struct m_ext2fs *fs)
479 {
480 #ifdef __minix
481 	errexit("%s: calcsb: can't read disk label under minix", dev);
482 #else
483 	struct disklabel *lp;
484 	struct partition *pp;
485 	char *cp;
486 
487 	cp = strchr(dev, '\0');
488 	if (cp-- == dev ||
489 	    ((*cp < 'a' || *cp > 'h') && !isdigit((unsigned char)*cp))) {
490 		pfatal("%s: CANNOT FIGURE OUT FILE SYSTEM PARTITION\n", dev);
491 		return 0;
492 	}
493 	lp = getdisklabel(dev, devfd);
494 	if (isdigit((unsigned char)*cp))
495 		pp = &lp->d_partitions[0];
496 	else
497 		pp = &lp->d_partitions[*cp - 'a'];
498 	if (pp->p_fstype != FS_EX2FS) {
499 		pfatal("%s: NOT LABELED AS A EXT2 FILE SYSTEM (%s)\n",
500 		    dev, pp->p_fstype < FSMAXTYPES ?
501 		    fstypenames[pp->p_fstype] : "unknown");
502 		return 0;
503 	}
504 	memset(fs, 0, sizeof(struct m_ext2fs));
505 	fs->e2fs_bsize = pp->p_fsize;
506 	fs->e2fs.e2fs_log_bsize = pp->p_fsize / 1024;
507 	fs->e2fs.e2fs_bcount = (pp->p_size * DEV_BSIZE) / fs->e2fs_bsize;
508 	fs->e2fs.e2fs_first_dblock = (fs->e2fs.e2fs_log_bsize == 0) ? 1 : 0;
509 	fs->e2fs.e2fs_bpg = fs->e2fs_bsize * NBBY;
510 	fs->e2fs_bshift = LOG_MINBSIZE + fs->e2fs.e2fs_log_bsize;
511 	fs->e2fs_qbmask = fs->e2fs_bsize - 1;
512 	fs->e2fs_bmask = ~fs->e2fs_qbmask;
513 	fs->e2fs_ncg =
514 	    howmany(fs->e2fs.e2fs_bcount - fs->e2fs.e2fs_first_dblock,
515 	    fs->e2fs.e2fs_bpg);
516 	fs->e2fs_fsbtodb = fs->e2fs.e2fs_log_bsize + 1;
517 	fs->e2fs_ngdb = howmany(fs->e2fs_ncg,
518 	    fs->e2fs_bsize / sizeof(struct ext2_gd));
519 
520 	return 1;
521 #endif
522 }
523 
524 static struct disklabel *
525 getdisklabel(const char *s, int fd)
526 {
527 	static struct disklabel lab;
528 
529 #ifdef __minix
530 	if (s == NULL)
531 		return NULL;
532 	errexit("%s: can't read disk label under minix", s);
533 #else
534 	if (ioctl(fd, DIOCGDINFO, (char *)&lab) < 0) {
535 		if (s == NULL)
536 			return NULL;
537 		pwarn("ioctl (GCINFO): %s\n", strerror(errno));
538 		errexit("%s: can't read disk label", s);
539 	}
540 #endif
541 	return &lab;
542 }
543 
544 daddr_t
545 cgoverhead(int c)
546 {
547 	int overh;
548 	overh =
549 	    1 /* block bitmap */ +
550 	    1 /* inode bitmap */ +
551 	    sblock.e2fs_itpg;
552 	if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
553 	    sblock.e2fs.e2fs_features_rocompat & EXT2F_ROCOMPAT_SPARSESUPER) {
554 		if (cg_has_sb(c) == 0)
555 			return overh;
556 	}
557 	overh += 1 /* superblock */ + sblock.e2fs_ngdb;
558 	return overh;
559 }
560