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setup.c revision 1.9
      1 /*	$NetBSD: setup.c,v 1.9 1999/02/01 15:20:14 bouyer Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1997 Manuel Bouyer.
      5  * Copyright (c) 1980, 1986, 1993
      6  *	The Regents of the University of California.  All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *	notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *	notice, this list of conditions and the following disclaimer in the
     15  *	documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *	must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *	may be used to endorse or promote products derived from this software
     22  *	without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 #include <sys/cdefs.h>
     38 #ifndef lint
     39 #if 0
     40 static char sccsid[] = "@(#)setup.c	8.5 (Berkeley) 11/23/94";
     41 #else
     42 __RCSID("$NetBSD: setup.c,v 1.9 1999/02/01 15:20:14 bouyer Exp $");
     43 #endif
     44 #endif /* not lint */
     45 
     46 #define FSTYPENAMES
     47 #include <sys/param.h>
     48 #include <sys/time.h>
     49 #include <ufs/ext2fs/ext2fs_dinode.h>
     50 #include <ufs/ext2fs/ext2fs.h>
     51 #include <sys/stat.h>
     52 #include <sys/ioctl.h>
     53 #include <sys/disklabel.h>
     54 #include <sys/file.h>
     55 
     56 #include <errno.h>
     57 #include <stdio.h>
     58 #include <stdlib.h>
     59 #include <string.h>
     60 #include <ctype.h>
     61 
     62 #include "fsck.h"
     63 #include "extern.h"
     64 #include "fsutil.h"
     65 
     66 #define POWEROF2(num)	(((num) & ((num) - 1)) == 0)
     67 
     68 void badsb __P((int, char *));
     69 int calcsb __P((const char *, int, struct m_ext2fs *));
     70 static struct disklabel *getdisklabel __P((const char *, int));
     71 static int readsb __P((int));
     72 
     73 int
     74 setup(dev)
     75 	const char *dev;
     76 {
     77 	long cg, asked, i;
     78 	long bmapsize;
     79 	struct disklabel *lp;
     80 	off_t sizepb;
     81 	struct stat statb;
     82 	struct m_ext2fs proto;
     83 	int doskipclean;
     84 	u_int64_t maxfilesize;
     85 
     86 	havesb = 0;
     87 	fswritefd = -1;
     88 	doskipclean = skipclean;
     89 	if (stat(dev, &statb) < 0) {
     90 		printf("Can't stat %s: %s\n", dev, strerror(errno));
     91 		return (0);
     92 	}
     93 	if (!S_ISCHR(statb.st_mode)) {
     94 		pfatal("%s is not a character device", dev);
     95 		if (reply("CONTINUE") == 0)
     96 			return (0);
     97 	}
     98 	if ((fsreadfd = open(dev, O_RDONLY)) < 0) {
     99 		printf("Can't open %s: %s\n", dev, strerror(errno));
    100 		return (0);
    101 	}
    102 	if (preen == 0)
    103 		printf("** %s", dev);
    104 	if (nflag || (fswritefd = open(dev, O_WRONLY)) < 0) {
    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((char *)NULL, fsreadfd)) != NULL)
    121 		dev_bsize = secsize = lp->d_secsize;
    122 	else
    123 		dev_bsize = secsize = DEV_BSIZE;
    124 	/*
    125 	 * Read in the superblock, looking for alternates if necessary
    126 	 */
    127 	if (readsb(1) == 0) {
    128 		if (bflag || preen || calcsb(dev, fsreadfd, &proto) == 0)
    129 			return(0);
    130 		if (reply("LOOK FOR ALTERNATE SUPERBLOCKS") == 0)
    131 			return (0);
    132 		for (cg = 1; cg < proto.e2fs_ncg; cg++) {
    133 			bflag = fsbtodb(&proto,
    134 				cg * proto.e2fs.e2fs_bpg + proto.e2fs.e2fs_first_dblock);
    135 			if (readsb(0) != 0)
    136 				break;
    137 		}
    138 		if (cg >= proto.e2fs_ncg) {
    139 			printf("%s %s\n%s %s\n%s %s\n",
    140 				"SEARCH FOR ALTERNATE SUPER-BLOCK",
    141 				"FAILED. YOU MUST USE THE",
    142 				"-b OPTION TO FSCK_FFS TO SPECIFY THE",
    143 				"LOCATION OF AN ALTERNATE",
    144 				"SUPER-BLOCK TO SUPPLY NEEDED",
    145 				"INFORMATION; SEE fsck_ext2fs(8).");
    146 			return(0);
    147 		}
    148 		doskipclean = 0;
    149 		pwarn("USING ALTERNATE SUPERBLOCK AT %d\n", bflag);
    150 	}
    151 	if (debug)
    152 		printf("state = %d\n", sblock.e2fs.e2fs_state);
    153 	if (sblock.e2fs.e2fs_state == E2FS_ISCLEAN) {
    154 		if (doskipclean) {
    155 			pwarn("%sile system is clean; not checking\n",
    156 				preen ? "f" : "** F");
    157 			return (-1);
    158 		}
    159 		if (!preen)
    160 			pwarn("** File system is already clean\n");
    161 	}
    162 	maxfsblock = sblock.e2fs.e2fs_bcount;
    163 	maxino = sblock.e2fs_ncg * sblock.e2fs.e2fs_ipg;
    164 	sizepb = sblock.e2fs_bsize;
    165 	maxfilesize = sblock.e2fs_bsize * NDADDR - 1;
    166 	for (i = 0; i < NIADDR; i++) {
    167 		sizepb *= NINDIR(&sblock);
    168 		maxfilesize += sizepb;
    169 	}
    170 	/*
    171 	 * Check and potentially fix certain fields in the super block.
    172 	 */
    173 	if ((sblock.e2fs.e2fs_rbcount < 0) ||
    174 			(sblock.e2fs.e2fs_rbcount > sblock.e2fs.e2fs_bcount)) {
    175 		pfatal("IMPOSSIBLE RESERVED BLOCK COUNT=%d IN SUPERBLOCK",
    176 			sblock.e2fs.e2fs_rbcount);
    177 		if (reply("SET TO DEFAULT") == 1) {
    178 			sblock.e2fs.e2fs_rbcount = sblock.e2fs.e2fs_bcount * 0.1;
    179 			sbdirty();
    180 			dirty(&asblk);
    181 		}
    182 	}
    183 	if (sblock.e2fs.e2fs_bpg != sblock.e2fs.e2fs_fpg) {
    184 		pfatal("WRONG FPG=%d (BPG=%d) IN SUPERBLOCK",
    185 			sblock.e2fs.e2fs_fpg, sblock.e2fs.e2fs_bpg);
    186 		return 0;
    187 	}
    188 	if (asblk.b_dirty && !bflag) {
    189 		copyback_sb(&asblk);
    190 		flush(fswritefd, &asblk);
    191 	}
    192 	/*
    193 	 * read in the summary info.
    194 	 */
    195 
    196 	sblock.e2fs_gd = malloc(sblock.e2fs_ngdb * sblock.e2fs_bsize);
    197 	if (sblock.e2fs_gd == NULL)
    198 		errexit("out of memory\n");
    199 	asked = 0;
    200 	for (i=0; i < sblock.e2fs_ngdb; i++) {
    201 		if (bread(fsreadfd,(char *)
    202 			&sblock.e2fs_gd[i* sblock.e2fs_bsize / sizeof(struct ext2_gd)],
    203 			fsbtodb(&sblock, ((sblock.e2fs_bsize>1024)?0:1)+i+1),
    204 			sblock.e2fs_bsize) != 0 && !asked) {
    205 			pfatal("BAD SUMMARY INFORMATION");
    206 			if (reply("CONTINUE") == 0)
    207 				errexit("%s\n", "");
    208 			asked++;
    209 		}
    210 	}
    211 	/*
    212 	 * allocate and initialize the necessary maps
    213 	 */
    214 	bmapsize = roundup(howmany(maxfsblock, NBBY), sizeof(int16_t));
    215 	blockmap = calloc((unsigned)bmapsize, sizeof (char));
    216 	if (blockmap == NULL) {
    217 		printf("cannot alloc %u bytes for blockmap\n",
    218 			(unsigned)bmapsize);
    219 		goto badsblabel;
    220 	}
    221 	statemap = calloc((unsigned)(maxino + 2), sizeof(char));
    222 	if (statemap == NULL) {
    223 		printf("cannot alloc %u bytes for statemap\n",
    224 			(unsigned)(maxino + 1));
    225 		goto badsblabel;
    226 	}
    227 	lncntp = (int16_t *)calloc((unsigned)(maxino + 1), sizeof(int16_t));
    228 	if (lncntp == NULL) {
    229 		printf("cannot alloc %u bytes for lncntp\n",
    230 			(unsigned)((maxino + 1) * sizeof(int16_t)));
    231 		goto badsblabel;
    232 	}
    233 	for (numdirs = 0, cg = 0; cg < sblock.e2fs_ncg; cg++) {
    234 		numdirs += fs2h16(sblock.e2fs_gd[cg].ext2bgd_ndirs);
    235 	}
    236 	inplast = 0;
    237 	listmax = numdirs + 10;
    238 	inpsort = (struct inoinfo **)calloc((unsigned)listmax,
    239 		sizeof(struct inoinfo *));
    240 	inphead = (struct inoinfo **)calloc((unsigned)numdirs,
    241 		sizeof(struct inoinfo *));
    242 	if (inpsort == NULL || inphead == NULL) {
    243 		printf("cannot alloc %u bytes for inphead\n",
    244 			(unsigned)(numdirs * sizeof(struct inoinfo *)));
    245 		goto badsblabel;
    246 	}
    247 	bufinit();
    248 	return (1);
    249 
    250 badsblabel:
    251 	ckfini(0);
    252 	return (0);
    253 }
    254 
    255 /*
    256  * Read in the super block and its summary info, convert to host byte order.
    257  */
    258 static int
    259 readsb(listerr)
    260 	int listerr;
    261 {
    262 	daddr_t super = bflag ? bflag : SBOFF / dev_bsize;
    263 
    264 	if (bread(fsreadfd, (char *)sblk.b_un.b_fs, super, (long)SBSIZE) != 0)
    265 		return (0);
    266 	sblk.b_bno = super;
    267 	sblk.b_size = SBSIZE;
    268 
    269 	/* Copy the superblock in memory */
    270 	sblock.e2fs.e2fs_icount = fs2h32(sblk.b_un.b_fs->e2fs_icount);
    271 	sblock.e2fs.e2fs_bcount = fs2h32(sblk.b_un.b_fs->e2fs_bcount);
    272 	sblock.e2fs.e2fs_rbcount = fs2h32(sblk.b_un.b_fs->e2fs_rbcount);
    273 	sblock.e2fs.e2fs_fbcount = fs2h32(sblk.b_un.b_fs->e2fs_fbcount);
    274 	sblock.e2fs.e2fs_ficount = fs2h32(sblk.b_un.b_fs->e2fs_ficount);
    275 	sblock.e2fs.e2fs_first_dblock = fs2h32(sblk.b_un.b_fs->e2fs_first_dblock);
    276 	sblock.e2fs.e2fs_log_bsize = fs2h32(sblk.b_un.b_fs->e2fs_log_bsize);
    277 	sblock.e2fs.e2fs_fsize = fs2h32(sblk.b_un.b_fs->e2fs_fsize);
    278 	sblock.e2fs.e2fs_bpg = fs2h32(sblk.b_un.b_fs->e2fs_bpg);
    279 	sblock.e2fs.e2fs_fpg = fs2h32(sblk.b_un.b_fs->e2fs_fpg);
    280 	sblock.e2fs.e2fs_ipg = fs2h32(sblk.b_un.b_fs->e2fs_ipg);
    281 	sblock.e2fs.e2fs_mtime = fs2h32(sblk.b_un.b_fs->e2fs_mtime);
    282 	sblock.e2fs.e2fs_wtime = fs2h32(sblk.b_un.b_fs->e2fs_wtime);
    283 	sblock.e2fs.e2fs_lastfsck = fs2h32(sblk.b_un.b_fs->e2fs_lastfsck);
    284 	sblock.e2fs.e2fs_fsckintv = fs2h32(sblk.b_un.b_fs->e2fs_fsckintv);
    285 	sblock.e2fs.e2fs_creator = fs2h32(sblk.b_un.b_fs->e2fs_creator);
    286 	sblock.e2fs.e2fs_rev = fs2h32(sblk.b_un.b_fs->e2fs_rev);
    287 	sblock.e2fs.e2fs_mnt_count = fs2h16(sblk.b_un.b_fs->e2fs_mnt_count);
    288 	sblock.e2fs.e2fs_max_mnt_count = fs2h16(sblk.b_un.b_fs->e2fs_max_mnt_count);
    289 	sblock.e2fs.e2fs_magic = fs2h16(sblk.b_un.b_fs->e2fs_magic);
    290 	sblock.e2fs.e2fs_state = fs2h16(sblk.b_un.b_fs->e2fs_state);
    291 	sblock.e2fs.e2fs_beh = fs2h16(sblk.b_un.b_fs->e2fs_beh);
    292 	sblock.e2fs.e2fs_ruid = fs2h16(sblk.b_un.b_fs->e2fs_ruid);
    293 	sblock.e2fs.e2fs_rgid = fs2h16(sblk.b_un.b_fs->e2fs_rgid);
    294 
    295 	/*
    296 	 * run a few consistency checks of the super block
    297 	 */
    298 	if (sblock.e2fs.e2fs_magic != E2FS_MAGIC) {
    299 		badsb(listerr, "MAGIC NUMBER WRONG"); return (0);
    300 	}
    301 	if (sblock.e2fs.e2fs_log_bsize > 2) {
    302 		badsb(listerr, "BAD LOG_BSIZE"); return (0);
    303 	}
    304 
    305 	/* compute the dynamic fields of the in-memory sb */
    306 	/* compute dynamic sb infos */
    307 	sblock.e2fs_ncg =
    308 		howmany(sblock.e2fs.e2fs_bcount - sblock.e2fs.e2fs_first_dblock,
    309 		sblock.e2fs.e2fs_bpg);
    310 	/* XXX assume hw bsize = 512 */
    311 	sblock.e2fs_fsbtodb = sblock.e2fs.e2fs_log_bsize + 1;
    312 	sblock.e2fs_bsize = 1024 << sblock.e2fs.e2fs_log_bsize;
    313 	sblock.e2fs_bshift = LOG_MINBSIZE + sblock.e2fs.e2fs_log_bsize;
    314 	sblock.e2fs_qbmask = sblock.e2fs_bsize - 1;
    315 	sblock.e2fs_bmask = ~sblock.e2fs_qbmask;
    316 	sblock.e2fs_ngdb = howmany(sblock.e2fs_ncg,
    317 		sblock.e2fs_bsize / sizeof(struct ext2_gd));
    318 	sblock.e2fs_ipb = sblock.e2fs_bsize / sizeof(struct ext2fs_dinode);
    319 	sblock.e2fs_itpg = sblock.e2fs.e2fs_ipg/sblock.e2fs_ipb;
    320 
    321 	cgoverhead =	1 /* super block */ +
    322 					sblock.e2fs_ngdb +
    323 					1 /* block bitmap */ +
    324 					1 /* inode bitmap */ +
    325 					sblock.e2fs_itpg;
    326 
    327 	if (debug) /* DDD */
    328 		printf("cg overhead %d blocks \n", cgoverhead);
    329 	/*
    330 	 * Compute block size that the filesystem is based on,
    331 	 * according to fsbtodb, and adjust superblock block number
    332 	 * so we can tell if this is an alternate later.
    333 	 */
    334 	super *= dev_bsize;
    335 	dev_bsize = sblock.e2fs_bsize / fsbtodb(&sblock, 1);
    336 	sblk.b_bno = super / dev_bsize;
    337 
    338 	getblk(&asblk, 1 * sblock.e2fs.e2fs_bpg + sblock.e2fs.e2fs_first_dblock,
    339 		(long)SBSIZE);
    340 	if (asblk.b_errs)
    341 		return (0);
    342 	if (bflag) {
    343 		havesb = 1;
    344 		return (1);
    345 	}
    346 
    347 	/*
    348 	 * Set all possible fields that could differ, then do check
    349 	 * of whole super block against an alternate super block.
    350 	 * When an alternate super-block is specified this check is skipped.
    351 	 */
    352 	asblk.b_un.b_fs->e2fs_rbcount = sblk.b_un.b_fs->e2fs_rbcount;
    353 	asblk.b_un.b_fs->e2fs_fbcount = sblk.b_un.b_fs->e2fs_fbcount;
    354 	asblk.b_un.b_fs->e2fs_ficount = sblk.b_un.b_fs->e2fs_ficount;
    355 	asblk.b_un.b_fs->e2fs_mtime = sblk.b_un.b_fs->e2fs_mtime;
    356 	asblk.b_un.b_fs->e2fs_wtime = sblk.b_un.b_fs->e2fs_wtime;
    357 	asblk.b_un.b_fs->e2fs_mnt_count = sblk.b_un.b_fs->e2fs_mnt_count;
    358 	asblk.b_un.b_fs->e2fs_max_mnt_count = sblk.b_un.b_fs->e2fs_max_mnt_count;
    359 	asblk.b_un.b_fs->e2fs_state = sblk.b_un.b_fs->e2fs_state;
    360 	asblk.b_un.b_fs->e2fs_beh = sblk.b_un.b_fs->e2fs_beh;
    361 	asblk.b_un.b_fs->e2fs_lastfsck = sblk.b_un.b_fs->e2fs_lastfsck;
    362 	asblk.b_un.b_fs->e2fs_fsckintv = sblk.b_un.b_fs->e2fs_fsckintv;
    363 	asblk.b_un.b_fs->e2fs_ruid = sblk.b_un.b_fs->e2fs_ruid;
    364 	asblk.b_un.b_fs->e2fs_rgid = sblk.b_un.b_fs->e2fs_rgid;
    365 	if (memcmp(sblk.b_un.b_fs, asblk.b_un.b_fs, SBSIZE)) {
    366 		if (debug) {
    367 			u_int32_t *nlp, *olp, *endlp;
    368 
    369 			printf("superblock mismatches\n");
    370 			nlp = (u_int32_t *)asblk.b_un.b_fs;
    371 			olp = (u_int32_t *)sblk.b_un.b_fs;
    372 			endlp = olp + (SBSIZE / sizeof *olp);
    373 			for ( ; olp < endlp; olp++, nlp++) {
    374 				if (*olp == *nlp)
    375 					continue;
    376 				printf("offset %ld, original %ld, alternate %ld\n",
    377 					(long)(olp - (u_int32_t *)sblk.b_un.b_fs),
    378 					(long)fs2h32(*olp),
    379 					(long)fs2h32(*nlp));
    380 			}
    381 		}
    382 		badsb(listerr,
    383 		"VALUES IN SUPER BLOCK DISAGREE WITH THOSE IN FIRST ALTERNATE");
    384 		return (0);
    385 	}
    386 	havesb = 1;
    387 	return (1);
    388 }
    389 
    390 void
    391 copyback_sb(bp)
    392 	struct bufarea *bp;
    393 {
    394 	/* Copy the in-memory superblock back to buffer */
    395 	bp->b_un.b_fs->e2fs_icount = fs2h32(sblock.e2fs.e2fs_icount);
    396 	bp->b_un.b_fs->e2fs_bcount = fs2h32(sblock.e2fs.e2fs_bcount);
    397 	bp->b_un.b_fs->e2fs_rbcount = fs2h32(sblock.e2fs.e2fs_rbcount);
    398 	bp->b_un.b_fs->e2fs_fbcount = fs2h32(sblock.e2fs.e2fs_fbcount);
    399 	bp->b_un.b_fs->e2fs_ficount = fs2h32(sblock.e2fs.e2fs_ficount);
    400 	bp->b_un.b_fs->e2fs_first_dblock =
    401 								fs2h32(sblock.e2fs.e2fs_first_dblock);
    402 	bp->b_un.b_fs->e2fs_log_bsize = fs2h32(sblock.e2fs.e2fs_log_bsize);
    403 	bp->b_un.b_fs->e2fs_fsize = fs2h32(sblock.e2fs.e2fs_fsize);
    404 	bp->b_un.b_fs->e2fs_bpg = fs2h32(sblock.e2fs.e2fs_bpg);
    405 	bp->b_un.b_fs->e2fs_fpg = fs2h32(sblock.e2fs.e2fs_fpg);
    406 	bp->b_un.b_fs->e2fs_ipg = fs2h32(sblock.e2fs.e2fs_ipg);
    407 	bp->b_un.b_fs->e2fs_mtime = fs2h32(sblock.e2fs.e2fs_mtime);
    408 	bp->b_un.b_fs->e2fs_wtime = fs2h32(sblock.e2fs.e2fs_wtime);
    409 	bp->b_un.b_fs->e2fs_lastfsck = fs2h32(sblock.e2fs.e2fs_lastfsck);
    410 	bp->b_un.b_fs->e2fs_fsckintv = fs2h32(sblock.e2fs.e2fs_fsckintv);
    411 	bp->b_un.b_fs->e2fs_creator = fs2h32(sblock.e2fs.e2fs_creator);
    412 	bp->b_un.b_fs->e2fs_rev = fs2h32(sblock.e2fs.e2fs_rev);
    413 	bp->b_un.b_fs->e2fs_mnt_count = fs2h16(sblock.e2fs.e2fs_mnt_count);
    414 	bp->b_un.b_fs->e2fs_max_mnt_count =
    415 								fs2h16(sblock.e2fs.e2fs_max_mnt_count);
    416 	bp->b_un.b_fs->e2fs_magic = fs2h16(sblock.e2fs.e2fs_magic);
    417 	bp->b_un.b_fs->e2fs_state = fs2h16(sblock.e2fs.e2fs_state);
    418 	bp->b_un.b_fs->e2fs_beh = fs2h16(sblock.e2fs.e2fs_beh);
    419 	bp->b_un.b_fs->e2fs_ruid = fs2h16(sblock.e2fs.e2fs_ruid);
    420 	bp->b_un.b_fs->e2fs_rgid = fs2h16(sblock.e2fs.e2fs_rgid);
    421 }
    422 
    423 void
    424 badsb(listerr, s)
    425 	int listerr;
    426 	char *s;
    427 {
    428 
    429 	if (!listerr)
    430 		return;
    431 	if (preen)
    432 		printf("%s: ", cdevname());
    433 	pfatal("BAD SUPER BLOCK: %s\n", s);
    434 }
    435 
    436 /*
    437  * Calculate a prototype superblock based on information in the disk label.
    438  * When done the cgsblock macro can be calculated and the fs_ncg field
    439  * can be used. Do NOT attempt to use other macros without verifying that
    440  * their needed information is available!
    441  */
    442 
    443 int
    444 calcsb(dev, devfd, fs)
    445 	const char *dev;
    446 	int devfd;
    447 	struct m_ext2fs *fs;
    448 {
    449 	struct disklabel *lp;
    450 	struct partition *pp;
    451 	char *cp;
    452 
    453 	cp = strchr(dev, '\0') - 1;
    454 	if ((cp == (char *)-1 || (*cp < 'a' || *cp > 'h')) && !isdigit(*cp)) {
    455 		pfatal("%s: CANNOT FIGURE OUT FILE SYSTEM PARTITION\n", dev);
    456 		return (0);
    457 	}
    458 	lp = getdisklabel(dev, devfd);
    459 	if (isdigit(*cp))
    460 		pp = &lp->d_partitions[0];
    461 	else
    462 		pp = &lp->d_partitions[*cp - 'a'];
    463 	if (pp->p_fstype != FS_EX2FS) {
    464 		pfatal("%s: NOT LABELED AS A EXT2 FILE SYSTEM (%s)\n",
    465 			dev, pp->p_fstype < FSMAXTYPES ?
    466 			fstypenames[pp->p_fstype] : "unknown");
    467 		return (0);
    468 	}
    469 	memset(fs, 0, sizeof(struct m_ext2fs));
    470 	fs->e2fs_bsize = pp->p_fsize;
    471 	fs->e2fs.e2fs_log_bsize = pp->p_fsize / 1024;
    472 	fs->e2fs.e2fs_bcount = (pp->p_size * DEV_BSIZE) / fs->e2fs_bsize;
    473 	fs->e2fs.e2fs_first_dblock = (fs->e2fs.e2fs_log_bsize == 0) ? 1 : 0;
    474 	fs->e2fs.e2fs_bpg = fs->e2fs_bsize * NBBY;
    475 	fs->e2fs_bshift = LOG_MINBSIZE + fs->e2fs.e2fs_log_bsize;
    476 	fs->e2fs_qbmask = fs->e2fs_bsize - 1;
    477 	fs->e2fs_bmask = ~fs->e2fs_qbmask;
    478 	fs->e2fs_ncg =
    479 		howmany(fs->e2fs.e2fs_bcount - fs->e2fs.e2fs_first_dblock,
    480 		fs->e2fs.e2fs_bpg);
    481 	fs->e2fs_fsbtodb = fs->e2fs.e2fs_log_bsize + 1;
    482 	fs->e2fs_ngdb = howmany(fs->e2fs_ncg,
    483 		fs->e2fs_bsize / sizeof(struct ext2_gd));
    484 
    485 	return (1);
    486 }
    487 
    488 static struct disklabel *
    489 getdisklabel(s, fd)
    490 	const char *s;
    491 	int	fd;
    492 {
    493 	static struct disklabel lab;
    494 
    495 	if (ioctl(fd, DIOCGDINFO, (char *)&lab) < 0) {
    496 		if (s == NULL)
    497 			return ((struct disklabel *)NULL);
    498 		pwarn("ioctl (GCINFO): %s\n", strerror(errno));
    499 		errexit("%s: can't read disk label\n", s);
    500 	}
    501 	return (&lab);
    502 }
    503