xref: /openbsd-src/sbin/fsck_ext2fs/setup.c (revision dfd61507032ca3584d263288cd98c2baa55b0df6)
1 /*	$OpenBSD: setup.c,v 1.35 2024/12/18 10:36:05 sthen Exp $	*/
2 /*	$NetBSD: setup.c,v 1.1 1997/06/11 11:22:01 bouyer Exp $	*/
3 
4 /*
5  * Copyright (c) 1997 Manuel Bouyer.
6  * Copyright (c) 1980, 1986, 1993
7  *	The Regents of the University of California.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #define DKTYPENAMES
35 #include <sys/param.h>	/* DEV_BSIZE roundup */
36 #include <sys/time.h>
37 #include <ufs/ext2fs/ext2fs_dinode.h>
38 #include <ufs/ext2fs/ext2fs.h>
39 #include <sys/stat.h>
40 #include <sys/ioctl.h>
41 #include <sys/dkio.h>
42 #include <sys/disklabel.h>
43 
44 #include <errno.h>
45 #include <fcntl.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <unistd.h>
49 #include <util.h>
50 #include <string.h>
51 #include <ctype.h>
52 #include <err.h>
53 
54 #include "fsck.h"
55 #include "extern.h"
56 #include "fsutil.h"
57 
58 #define POWEROF2(num)	(((num) & ((num) - 1)) == 0)
59 
60 void badsb(int, char *);
61 int calcsb(char *, int, struct m_ext2fs *, struct disklabel *);
62 static struct disklabel *getdisklabel(char *, int);
63 static int readsb(int);
64 static char rdevname[PATH_MAX];
65 
66 int
67 setup(char *dev)
68 {
69 	long cg, asked, i;
70 	long bmapsize;
71 	struct disklabel *lp;
72 	off_t sizepb;
73 	struct stat statb;
74 	struct m_ext2fs proto;
75 	char *realdev;
76 	int doskipclean;
77 	u_int64_t maxfilesize;
78 
79 	havesb = 0;
80 	fswritefd = -1;
81 	doskipclean = skipclean;
82 	if ((fsreadfd = opendev(dev, O_RDONLY, 0, &realdev)) == -1) {
83 		printf("Can't open %s: %s\n", dev, strerror(errno));
84 		return (0);
85 	}
86 	if (strncmp(dev, realdev, PATH_MAX) != 0) {
87 		blockcheck(unrawname(realdev));
88 		strlcpy(rdevname, realdev, sizeof(rdevname));
89 		setcdevname(rdevname, dev, preen);
90 	}
91 	if (fstat(fsreadfd, &statb) == -1) {
92 		printf("Can't stat %s: %s\n", realdev, strerror(errno));
93 		return (0);
94 	}
95 	if (!S_ISCHR(statb.st_mode)) {
96 		pfatal("%s is not a character device", realdev);
97 		if (reply("CONTINUE") == 0) {
98 			close(fsreadfd);
99 			return (0);
100 		}
101 	}
102 	if (preen == 0)
103 		printf("** %s", realdev);
104 	if (nflag || (fswritefd = opendev(dev, O_WRONLY, 0, NULL)) == -1) {
105 		fswritefd = -1;
106 		if (preen)
107 			pfatal("NO WRITE ACCESS");
108 		printf(" (NO WRITE)");
109 	}
110 	if (preen == 0)
111 		printf("\n");
112 	fsmodified = 0;
113 	lfdir = 0;
114 	initbarea(&sblk);
115 	initbarea(&asblk);
116 	sblk.b_un.b_buf = malloc(SBSIZE);
117 	asblk.b_un.b_buf = malloc(SBSIZE);
118 	if (sblk.b_un.b_buf == NULL || asblk.b_un.b_buf == NULL)
119 		errexit("cannot allocate space for superblock\n");
120 	if ((lp = getdisklabel(NULL, fsreadfd)) != NULL)
121 		secsize = lp->d_secsize;
122 	else
123 		secsize = DEV_BSIZE;
124 
125 	if (!hotroot()) {
126 #ifndef SMALL
127 		if (pledge("stdio getpw", NULL) == -1)
128 			err(1, "pledge");
129 #else
130 		if (pledge("stdio", NULL) == -1)
131 			err(1, "pledge");
132 #endif
133 	}
134 
135 	/*
136 	 * Read in the superblock, looking for alternates if necessary
137 	 */
138 	if (readsb(1) == 0) {
139 		if (bflag || preen || calcsb(realdev, fsreadfd, &proto, lp) == 0)
140 			return(0);
141 		if (reply("LOOK FOR ALTERNATE SUPERBLOCKS") == 0)
142 			return (0);
143 		for (cg = 1; cg < proto.e2fs_ncg; cg++) {
144 			bflag = fsbtodb(&proto,
145 				cg * proto.e2fs.e2fs_bpg + proto.e2fs.e2fs_first_dblock);
146 			if (readsb(0) != 0)
147 				break;
148 		}
149 		if (cg >= proto.e2fs_ncg) {
150 			printf("%s %s\n%s %s\n%s %s\n",
151 			    "SEARCH FOR ALTERNATE SUPER-BLOCK",
152 			    "FAILED. YOU MUST USE THE",
153 			    "-b OPTION TO FSCK_FFS TO SPECIFY THE",
154 			    "LOCATION OF AN ALTERNATE",
155 			    "SUPER-BLOCK TO SUPPLY NEEDED",
156 			    "INFORMATION; SEE fsck_ext2fs(8).");
157 			return(0);
158 		}
159 		doskipclean = 0;
160 		pwarn("USING ALTERNATE SUPERBLOCK AT %d\n", bflag);
161 	}
162 	if (debug)
163 		printf("state = %d\n", sblock.e2fs.e2fs_state);
164 	if (sblock.e2fs.e2fs_state == E2FS_ISCLEAN) {
165 		if (doskipclean) {
166 			pwarn("%sile system is clean; not checking\n",
167 			    preen ? "f" : "** F");
168 			return (-1);
169 		}
170 		if (!preen)
171 			pwarn("** File system is already clean\n");
172 	}
173 	maxfsblock = sblock.e2fs.e2fs_bcount;
174 	maxino = sblock.e2fs_ncg * sblock.e2fs.e2fs_ipg;
175 	sizepb = sblock.e2fs_bsize;
176 	maxfilesize = sblock.e2fs_bsize * NDADDR - 1;
177 	for (i = 0; i < NIADDR; i++) {
178 		sizepb *= NINDIR(&sblock);
179 		maxfilesize += sizepb;
180 	}
181 	/*
182 	 * Check and potentially fix certain fields in the super block.
183 	 */
184 	if (/* (sblock.e2fs.e2fs_rbcount < 0) || */
185 			(sblock.e2fs.e2fs_rbcount > sblock.e2fs.e2fs_bcount)) {
186 		pfatal("IMPOSSIBLE RESERVED BLOCK COUNT=%d IN SUPERBLOCK",
187 			sblock.e2fs.e2fs_rbcount);
188 		if (reply("SET TO DEFAULT") == 1) {
189 			sblock.e2fs.e2fs_rbcount = sblock.e2fs.e2fs_bcount * 0.1;
190 			sbdirty();
191 			dirty(&asblk);
192 		}
193 	}
194 	if (sblock.e2fs.e2fs_bpg != sblock.e2fs.e2fs_fpg) {
195 		pfatal("WRONG FPG=%d (BPG=%d) IN SUPERBLOCK",
196 			sblock.e2fs.e2fs_fpg, sblock.e2fs.e2fs_bpg);
197 		return 0;
198 	}
199 	if (asblk.b_dirty && !bflag) {
200 		copyback_sb(&asblk);
201 		flush(fswritefd, &asblk);
202 	}
203 	/*
204 	 * read in the summary info.
205 	 */
206 
207 	sblock.e2fs_gd = calloc(sblock.e2fs_ngdb, sblock.e2fs_bsize);
208 	if (sblock.e2fs_gd == NULL)
209 		errexit("out of memory\n");
210 	asked = 0;
211 	for (i=0; i < sblock.e2fs_ngdb; i++) {
212 		if (bread(fsreadfd,(char *)
213 			&sblock.e2fs_gd[i* sblock.e2fs_bsize / sizeof(struct ext2_gd)],
214 			fsbtodb(&sblock, ((sblock.e2fs_bsize>1024)?0:1)+i+1),
215 			sblock.e2fs_bsize) != 0 && !asked) {
216 			pfatal("BAD SUMMARY INFORMATION");
217 			if (reply("CONTINUE") == 0)
218 				errexit("%s\n", "");
219 			asked++;
220 		}
221 	}
222 	/*
223 	 * allocate and initialize the necessary maps
224 	 */
225 	bmapsize = roundup(howmany(maxfsblock, NBBY), sizeof(int16_t));
226 	blockmap = calloc((unsigned)bmapsize, sizeof (char));
227 	if (blockmap == NULL) {
228 		printf("cannot alloc %u bytes for blockmap\n",
229 			(unsigned)bmapsize);
230 		goto badsblabel;
231 	}
232 	statemap = calloc((unsigned)(maxino + 2), sizeof(char));
233 	if (statemap == NULL) {
234 		printf("cannot alloc %u bytes for statemap\n",
235 			(unsigned)(maxino + 1));
236 		goto badsblabel;
237 	}
238 	typemap = calloc((unsigned)(maxino + 1), sizeof(u_char));
239 	if (typemap == NULL) {
240 		printf("cannot alloc %u bytes for typemap\n",
241 		    (unsigned)(maxino + 1));
242 		goto badsblabel;
243 	}
244 	lncntp = calloc((unsigned)(maxino + 1), sizeof(int16_t));
245 	if (lncntp == NULL) {
246 		printf("cannot alloc %u bytes for lncntp\n",
247 			(unsigned)((maxino + 1) * sizeof(int16_t)));
248 		goto badsblabel;
249 	}
250 	for (numdirs = 0, cg = 0; cg < sblock.e2fs_ncg; cg++) {
251 		numdirs += letoh16(sblock.e2fs_gd[cg].ext2bgd_ndirs);
252 	}
253 	inplast = 0;
254 	listmax = numdirs + 10;
255 	inpsort = calloc((unsigned)listmax, sizeof(struct inoinfo *));
256 	inphead = calloc((unsigned)numdirs, sizeof(struct inoinfo *));
257 	if (inpsort == NULL || inphead == NULL) {
258 		printf("cannot alloc %u bytes for inphead\n",
259 			(unsigned)(numdirs * sizeof(struct inoinfo *)));
260 		goto badsblabel;
261 	}
262 	bufinit();
263 	return (1);
264 
265 badsblabel:
266 	ckfini(0);
267 	return (0);
268 }
269 
270 /*
271  * Read in the super block and its summary info.
272  */
273 static int
274 readsb(int listerr)
275 {
276 	daddr32_t super = bflag ? bflag : SBOFF / DEV_BSIZE;
277 
278 	if (bread(fsreadfd, (char *)sblk.b_un.b_fs, super, (long)SBSIZE) != 0)
279 		return (0);
280 	sblk.b_bno = super;
281 	sblk.b_size = SBSIZE;
282 
283 	/* Copy the superblock in memory */
284 	e2fs_sbload(sblk.b_un.b_fs, &sblock.e2fs);
285 
286 	/*
287 	 * run a few consistency checks of the super block
288 	 */
289 	if (sblock.e2fs.e2fs_magic != E2FS_MAGIC) {
290 		badsb(listerr, "MAGIC NUMBER WRONG"); return (0);
291 	}
292 	if (sblock.e2fs.e2fs_log_bsize > 2) {
293 		badsb(listerr, "BAD LOG_BSIZE"); return (0);
294 	}
295 	if (sblock.e2fs.e2fs_bpg == 0) {
296 		badsb(listerr, "BAD BLOCKS PER GROUP"); return (0);
297 	}
298 
299 	/* compute the dynamic fields of the in-memory sb */
300 	/* compute dynamic sb infos */
301 	sblock.e2fs_ncg =
302 		howmany(sblock.e2fs.e2fs_bcount - sblock.e2fs.e2fs_first_dblock,
303 		sblock.e2fs.e2fs_bpg);
304 	/* XXX assume hw bsize = 512 */
305 	sblock.e2fs_fsbtodb = sblock.e2fs.e2fs_log_bsize + 1;
306 	sblock.e2fs_bsize = 1024 << sblock.e2fs.e2fs_log_bsize;
307 	sblock.e2fs_bshift = LOG_MINBSIZE + sblock.e2fs.e2fs_log_bsize;
308 	sblock.e2fs_qbmask = sblock.e2fs_bsize - 1;
309 	sblock.e2fs_bmask = ~sblock.e2fs_qbmask;
310 	sblock.e2fs_ngdb = howmany(sblock.e2fs_ncg,
311 		sblock.e2fs_bsize / sizeof(struct ext2_gd));
312 	sblock.e2fs_ipb = sblock.e2fs_bsize / EXT2_DINODE_SIZE(&sblock);
313 	sblock.e2fs_itpg = sblock.e2fs.e2fs_ipg/sblock.e2fs_ipb;
314 
315 	/*
316 	 * Compute block size that the filesystem is based on,
317 	 * according to fsbtodb, and adjust superblock block number
318 	 * so we can tell if this is an alternate later.
319 	 */
320 	sblk.b_bno = super / DEV_BSIZE;
321 
322 	if (sblock.e2fs_ncg == 1) {
323 		/* no alternate superblock; assume it's okey */
324 		havesb = 1;
325 		return 1;
326 	}
327 
328 	getblk(&asblk, 1 * sblock.e2fs.e2fs_bpg + sblock.e2fs.e2fs_first_dblock,
329 		(long)SBSIZE);
330 	if (asblk.b_errs)
331 		return (0);
332 	if (bflag) {
333 		havesb = 1;
334 		return (1);
335 	}
336 
337 	/*
338 	 * Set all possible fields that could differ, then do check
339 	 * of whole super block against an alternate super block.
340 	 * When an alternate super-block is specified this check is skipped.
341 	 */
342 	asblk.b_un.b_fs->e2fs_rbcount = sblk.b_un.b_fs->e2fs_rbcount;
343 	asblk.b_un.b_fs->e2fs_fbcount = sblk.b_un.b_fs->e2fs_fbcount;
344 	asblk.b_un.b_fs->e2fs_ficount = sblk.b_un.b_fs->e2fs_ficount;
345 	asblk.b_un.b_fs->e2fs_mtime = sblk.b_un.b_fs->e2fs_mtime;
346 	asblk.b_un.b_fs->e2fs_wtime = sblk.b_un.b_fs->e2fs_wtime;
347 	asblk.b_un.b_fs->e2fs_mnt_count = sblk.b_un.b_fs->e2fs_mnt_count;
348 	asblk.b_un.b_fs->e2fs_max_mnt_count = sblk.b_un.b_fs->e2fs_max_mnt_count;
349 	asblk.b_un.b_fs->e2fs_state = sblk.b_un.b_fs->e2fs_state;
350 	asblk.b_un.b_fs->e2fs_beh = sblk.b_un.b_fs->e2fs_beh;
351 	asblk.b_un.b_fs->e2fs_lastfsck = sblk.b_un.b_fs->e2fs_lastfsck;
352 	asblk.b_un.b_fs->e2fs_fsckintv = sblk.b_un.b_fs->e2fs_fsckintv;
353 	asblk.b_un.b_fs->e2fs_ruid = sblk.b_un.b_fs->e2fs_ruid;
354 	asblk.b_un.b_fs->e2fs_rgid = sblk.b_un.b_fs->e2fs_rgid;
355 	asblk.b_un.b_fs->e2fs_block_group_nr =
356 	    sblk.b_un.b_fs->e2fs_block_group_nr;
357 	asblk.b_un.b_fs->e2fs_features_rocompat &= ~EXT2F_ROCOMPAT_LARGE_FILE;
358 	asblk.b_un.b_fs->e2fs_features_rocompat |=
359 	    sblk.b_un.b_fs->e2fs_features_rocompat & EXT2F_ROCOMPAT_LARGE_FILE;
360 	memcpy(asblk.b_un.b_fs->e2fs_fsmnt, sblk.b_un.b_fs->e2fs_fsmnt,
361 	    sizeof(sblk.b_un.b_fs->e2fs_fsmnt));
362 	asblk.b_un.b_fs->e2fs_kbytes_written = sblk.b_un.b_fs->e2fs_kbytes_written;
363 
364 	if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
365 	    ((sblock.e2fs.e2fs_features_incompat & ~EXT2F_INCOMPAT_SUPP) ||
366 	    (sblock.e2fs.e2fs_features_rocompat & ~EXT2F_ROCOMPAT_SUPP))) {
367 		if (debug) {
368 			printf("compat 0x%08x, incompat 0x%08x, compat_ro "
369 			    "0x%08x\n",
370 			    sblock.e2fs.e2fs_features_compat,
371 			    sblock.e2fs.e2fs_features_incompat,
372 			    sblock.e2fs.e2fs_features_rocompat);
373 		}
374 		badsb(listerr,"INCOMPATIBLE FEATURE BITS IN SUPER BLOCK");
375 		return 0;
376 	}
377 	if (memcmp(sblk.b_un.b_fs, asblk.b_un.b_fs, SBSIZE)) {
378 		if (debug) {
379 			u_int32_t *nlp, *olp, *endlp;
380 
381 			printf("superblock mismatches\n");
382 			nlp = (u_int32_t *)asblk.b_un.b_fs;
383 			olp = (u_int32_t *)sblk.b_un.b_fs;
384 			endlp = olp + (SBSIZE / sizeof *olp);
385 			for ( ; olp < endlp; olp++, nlp++) {
386 				if (*olp == *nlp)
387 					continue;
388 				printf("offset %ld, original %ld, alternate %ld\n",
389 					(long)(olp - (u_int32_t *)sblk.b_un.b_fs),
390 					(long)letoh32(*olp),
391 					(long)letoh32(*nlp));
392 			}
393 		}
394 		badsb(listerr,
395 		"VALUES IN SUPER BLOCK DISAGREE WITH THOSE IN FIRST ALTERNATE");
396 		return (0);
397 	}
398 	havesb = 1;
399 	return (1);
400 }
401 
402 void
403 copyback_sb(struct bufarea *bp)
404 {
405 	/* Copy the in-memory superblock back to buffer */
406 	bp->b_un.b_fs->e2fs_icount = letoh32(sblock.e2fs.e2fs_icount);
407 	bp->b_un.b_fs->e2fs_bcount = letoh32(sblock.e2fs.e2fs_bcount);
408 	bp->b_un.b_fs->e2fs_rbcount = letoh32(sblock.e2fs.e2fs_rbcount);
409 	bp->b_un.b_fs->e2fs_fbcount = letoh32(sblock.e2fs.e2fs_fbcount);
410 	bp->b_un.b_fs->e2fs_ficount = letoh32(sblock.e2fs.e2fs_ficount);
411 	bp->b_un.b_fs->e2fs_first_dblock =
412 					letoh32(sblock.e2fs.e2fs_first_dblock);
413 	bp->b_un.b_fs->e2fs_log_bsize = letoh32(sblock.e2fs.e2fs_log_bsize);
414 	bp->b_un.b_fs->e2fs_log_fsize = letoh32(sblock.e2fs.e2fs_log_fsize);
415 	bp->b_un.b_fs->e2fs_bpg = letoh32(sblock.e2fs.e2fs_bpg);
416 	bp->b_un.b_fs->e2fs_fpg = letoh32(sblock.e2fs.e2fs_fpg);
417 	bp->b_un.b_fs->e2fs_ipg = letoh32(sblock.e2fs.e2fs_ipg);
418 	bp->b_un.b_fs->e2fs_mtime = letoh32(sblock.e2fs.e2fs_mtime);
419 	bp->b_un.b_fs->e2fs_wtime = letoh32(sblock.e2fs.e2fs_wtime);
420 	bp->b_un.b_fs->e2fs_lastfsck = letoh32(sblock.e2fs.e2fs_lastfsck);
421 	bp->b_un.b_fs->e2fs_fsckintv = letoh32(sblock.e2fs.e2fs_fsckintv);
422 	bp->b_un.b_fs->e2fs_creator = letoh32(sblock.e2fs.e2fs_creator);
423 	bp->b_un.b_fs->e2fs_rev = letoh32(sblock.e2fs.e2fs_rev);
424 	bp->b_un.b_fs->e2fs_mnt_count = letoh16(sblock.e2fs.e2fs_mnt_count);
425 	bp->b_un.b_fs->e2fs_max_mnt_count =
426 					letoh16(sblock.e2fs.e2fs_max_mnt_count);
427 	bp->b_un.b_fs->e2fs_magic = letoh16(sblock.e2fs.e2fs_magic);
428 	bp->b_un.b_fs->e2fs_state = letoh16(sblock.e2fs.e2fs_state);
429 	bp->b_un.b_fs->e2fs_beh = letoh16(sblock.e2fs.e2fs_beh);
430 	bp->b_un.b_fs->e2fs_ruid = letoh16(sblock.e2fs.e2fs_ruid);
431 	bp->b_un.b_fs->e2fs_rgid = letoh16(sblock.e2fs.e2fs_rgid);
432 }
433 
434 void
435 badsb(int listerr, char *s)
436 {
437 
438 	if (!listerr)
439 		return;
440 	if (preen)
441 		printf("%s: ", cdevname());
442 	pfatal("BAD SUPER BLOCK: %s\n", s);
443 }
444 
445 /*
446  * Calculate a prototype superblock based on information in the disk label.
447  * When done the cgsblock macro can be calculated and the fs_ncg field
448  * can be used. Do NOT attempt to use other macros without verifying that
449  * their needed information is available!
450  */
451 int
452 calcsb(char *dev, int devfd, struct m_ext2fs *fs, struct disklabel *lp)
453 {
454 	struct partition *pp;
455 	char *cp;
456 
457 	cp = strchr(dev, '\0');
458 	if ((cp == NULL || (cp[-1] < 'a' || cp[-1] >= 'a' + MAXPARTITIONS)) &&
459 	    !isdigit((unsigned char)cp[-1])) {
460 		pfatal("%s: CANNOT FIGURE OUT FILE SYSTEM PARTITION\n", dev);
461 		return (0);
462 	}
463 	cp--;
464 	if (lp == NULL)
465 		pfatal("%s: CANNOT READ DISKLABEL\n", dev);
466 	if (isdigit((unsigned char)*cp))
467 		pp = &lp->d_partitions[0];
468 	else
469 		pp = &lp->d_partitions[*cp - 'a'];
470 	if (pp->p_fstype != FS_EXT2FS) {
471 		pfatal("%s: NOT LABELED AS A EXT2 FILE SYSTEM (%s)\n",
472 			dev, pp->p_fstype < FSMAXTYPES ?
473 			fstypenames[pp->p_fstype] : "unknown");
474 		return (0);
475 	}
476 	memset(fs, 0, sizeof(struct m_ext2fs));
477 	fs->e2fs_bsize = DISKLABELV1_FFS_FSIZE(pp->p_fragblock); /* XXX */
478 	if (fs->e2fs_bsize == 0) {
479 		pfatal("%s: BLOCK SIZE DETERMINED TO BE ZERO\n", dev);
480 		return (0);
481 	}
482 	fs->e2fs.e2fs_log_bsize = fs->e2fs_bsize / 1024;
483 	fs->e2fs.e2fs_bcount = (pp->p_size * DEV_BSIZE) / fs->e2fs_bsize;
484 	fs->e2fs.e2fs_first_dblock = (fs->e2fs.e2fs_log_bsize == 0) ? 1 : 0;
485 	fs->e2fs.e2fs_bpg = fs->e2fs_bsize * NBBY;
486 	fs->e2fs_bshift = LOG_MINBSIZE + fs->e2fs.e2fs_log_bsize;
487 	fs->e2fs_qbmask = fs->e2fs_bsize - 1;
488 	fs->e2fs_bmask = ~fs->e2fs_qbmask;
489 	fs->e2fs_ncg =
490 		howmany(fs->e2fs.e2fs_bcount - fs->e2fs.e2fs_first_dblock,
491 		fs->e2fs.e2fs_bpg);
492 	fs->e2fs_fsbtodb = fs->e2fs.e2fs_log_bsize + 1;
493 	fs->e2fs_ngdb = howmany(fs->e2fs_ncg,
494 		fs->e2fs_bsize / sizeof(struct ext2_gd));
495 
496 	return (1);
497 }
498 
499 static struct disklabel *
500 getdisklabel(char *s, int fd)
501 {
502 	static struct disklabel lab;
503 
504 	if (ioctl(fd, DIOCGDINFO, (char *)&lab) == -1) {
505 		if (s == NULL)
506 			return (NULL);
507 		pwarn("ioctl (GCINFO): %s\n", strerror(errno));
508 		errexit("%s: can't read disk label\n", s);
509 	}
510 	return (&lab);
511 }
512 
513 daddr32_t
514 cgoverhead(int c)
515 {
516 	int overh;
517 	overh =	1 /* block bitmap */ +
518 		1 /* inode bitmap */ +
519 		sblock.e2fs_itpg;
520 	if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
521 	    sblock.e2fs.e2fs_features_rocompat & EXT2F_ROCOMPAT_SPARSE_SUPER) {
522 		if (cg_has_sb(c) == 0)
523 			return overh;
524 	}
525 	overh += 1 + sblock.e2fs_ngdb;
526 	return overh;
527 }
528