NetBSD/sbin/fsck_lfs/setup.c

679 lines
19 KiB
C

/* $NetBSD: setup.c,v 1.9 2001/07/13 20:30:19 perseant Exp $ */
/*
* Copyright (c) 1980, 1986, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* #define DKTYPENAMES */
#define FSTYPENAMES
#include <sys/param.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/disklabel.h>
#include <sys/file.h>
#include <ufs/ufs/dinode.h>
#include <sys/mount.h> /* XXX ufs/lfs/lfs.h should include this for
* us */
#include <ufs/lfs/lfs.h>
#include <ufs/lfs/lfs_extern.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "fsck.h"
#include "extern.h"
#include "fsutil.h"
struct bufarea asblk;
daddr_t *din_table;
SEGUSE *seg_table;
#define altsblock (*asblk.b_un.b_fs)
#define POWEROF2(num) (((num) & ((num) - 1)) == 0)
void badsb(int, char *);
int calcsb(const char *, int, struct lfs *);
static struct disklabel *getdisklabel(const char *, int);
static int readsb(int);
int lfs_maxino(void);
static daddr_t try_verify(struct lfs *, struct lfs *);
#ifdef DKTYPENAMES
int useless(void);
int
useless(void)
{
char **foo = (char **)dktypenames;
char **bar = (char **)fscknames;
return foo - bar;
}
#endif
static daddr_t
try_verify(struct lfs * osb, struct lfs * nsb)
{
daddr_t daddr;
SEGSUM *sp;
char *summary;
int bc, flag;
daddr = osb->lfs_offset;
summary = malloc(osb->lfs_sumsize);
while (daddr != nsb->lfs_offset) {
flag = 0;
oncemore:
/* Read in summary block */
bread(fsreadfd, summary, fsbtodb(osb, daddr), osb->lfs_sumsize);
sp = (SEGSUM *)summary;
/*
* Could be a superblock instead of a segment summary.
* XXX should use gseguse, but right now we need to do more
* setup before we can...fix this
*/
if (sp->ss_magic != SS_MAGIC ||
sp->ss_sumsum != cksum(&sp->ss_datasum, osb->lfs_sumsize -
sizeof(sp->ss_sumsum))) {
if (flag == 0) {
daddr += btofsb(osb, LFS_SBPAD);
goto oncemore;
}
return 0x0;
}
bc = check_summary(osb, sp, daddr);
if (bc == 0)
break;
daddr += btofsb(osb, osb->lfs_sumsize + bc);
if (dtosn(osb, daddr) != dtosn(osb, daddr +
btofsb(osb, osb->lfs_sumsize + osb->lfs_bsize)))
daddr = ((SEGSUM *)summary)->ss_next;
}
return daddr;
}
u_quad_t maxtable[] = {
/* 1 */ -1,
/* 2 */ -1,
/* 4 */ -1,
/* 8 */ -1,
/* 16 */ -1,
/* 32 */ -1,
/* 64 */ -1,
/* 128 */ -1,
/* 256 */ -1,
/* 512 */ NDADDR + 128 + 128 * 128 + 128 * 128 * 128,
/* 1024 */ NDADDR + 256 + 256 * 256 + 256 * 256 * 256,
/* 2048 */ NDADDR + 512 + 512 * 512 + 512 * 512 * 512,
/* 4096 */ NDADDR + 1024 + 1024 * 1024 + 1024 * 1024 * 1024,
/* 8192 */ 1 << 31,
/* 16 K */ 1 << 31,
/* 32 K */ 1 << 31,
};
int
setup(const char *dev)
{
long bmapsize;
struct disklabel *lp;
#if 0
long i;
off_t sizepb;
#endif
struct stat statb;
daddr_t daddr;
struct lfs proto;
int doskipclean;
u_int64_t maxfilesize;
struct lfs *sb0, *sb1, *osb, *nsb;
struct dinode *idinode;
havesb = 0;
fswritefd = -1;
doskipclean = skipclean;
if (stat(dev, &statb) < 0) {
printf("Can't stat %s: %s\n", dev, strerror(errno));
return (0);
}
if (!S_ISCHR(statb.st_mode)) {
pfatal("%s is not a character device", dev);
if (reply("CONTINUE") == 0)
return (0);
}
if ((fsreadfd = open(dev, O_RDONLY)) < 0) {
printf("Can't open %s: %s\n", dev, strerror(errno));
return (0);
}
if (preen == 0)
printf("** %s", dev);
if (nflag || (fswritefd = open(dev, O_WRONLY)) < 0) {
fswritefd = -1;
if (preen)
pfatal("NO WRITE ACCESS");
printf(" (NO WRITE)");
}
if (preen == 0)
printf("\n");
fsmodified = 0;
lfdir = 0;
initbarea(&sblk);
initbarea(&asblk);
sblk.b_un.b_buf = malloc(LFS_SBPAD);
asblk.b_un.b_buf = malloc(LFS_SBPAD);
if (sblk.b_un.b_buf == NULL || asblk.b_un.b_buf == NULL)
errexit("cannot allocate space for superblock\n");
if ((lp = getdisklabel((char *) NULL, fsreadfd)) != NULL)
dev_bsize = secsize = lp->d_secsize;
else
dev_bsize = secsize = DEV_BSIZE;
/*
* Read in the superblock, looking for alternates if necessary
*/
if (readsb(1) == 0) {
if (bflag || preen || calcsb(dev, fsreadfd, &proto) == 0)
return (0);
if (reply("LOOK FOR ALTERNATE SUPERBLOCKS") == 0)
return (0);
#if 0 /* XXX find the LFS way to do this */
for (cg = 0; cg < proto.lfs_ncg; cg++) {
bflag = fsbtodb(&proto, cgsblock(&proto, cg));
if (readsb(0) != 0)
break;
}
if (cg >= proto.lfs_ncg) {
printf("%s %s\n%s %s\n%s %s\n",
"SEARCH FOR ALTERNATE SUPER-BLOCK",
"FAILED. YOU MUST USE THE",
"-b OPTION TO FSCK_FFS TO SPECIFY THE",
"LOCATION OF AN ALTERNATE",
"SUPER-BLOCK TO SUPPLY NEEDED",
"INFORMATION; SEE fsck_ffs(8).");
return (0);
}
#else
pwarn("XXX Can't look for alternate superblocks yet\n");
return (0);
#endif
doskipclean = 0;
pwarn("USING ALTERNATE SUPERBLOCK AT %d\n", bflag);
}
bufinit();
if (bflag == 0x0 && idaddr == 0x0) {
/*
* If we read a proper superblock, but its address was not
* lfs_sboffs[0], we're holding a fake primary superblock,
* and need to read the real one.
*/
if (sblock.lfs_sboffs[0] != dbtofsb(&sblock,
LFS_LABELPAD / dev_bsize))
{
if (debug)
pwarn("Getting 'real' prinary superblock from 0x%x\n",
fsbtodb(&sblock, sblock.lfs_sboffs[0]));
bflag = fsbtodb(&sblock, sblock.lfs_sboffs[0]);
readsb(1);
bflag = 0;
}
/*
* Even if that superblock read in properly, it may not
* be guaranteed to point to a complete checkpoint.
* Read in the second superblock too, and take whichever
* of the two is *less* recent. --ks
*/
sb0 = malloc(sizeof(*sb0));
sb1 = malloc(sizeof(*sb1));
memcpy(sb0, &sblock, sizeof(*sb0));
bflag = fsbtodb(&sblock, sblock.lfs_sboffs[1]);
if (readsb(1) == 0) {
pwarn("COULDN'T READ ALT SUPERBLOCK AT BLK %d", bflag);
if (reply("ASSUME PRIMARY SUPERBLOCK IS GOOD") == 0) {
return (0);
} else {/* use primary as good */
memcpy(&sblock, sb0, sizeof(*sb0)); /* XXX cheating? */
}
} else {
memcpy(sb1, &sblock, sizeof(*sb1));
if (debug) {
if (sb0->lfs_version > 1) {
pwarn("sb0 sn=%lld, sb1 sn=%lld\n",
(long long)sb0->lfs_serial,
(long long)sblock.lfs_serial);
} else {
pwarn("sb0 %lld, sb1 %lld\n",
(long long)sb0->lfs_otstamp,
(long long)sblock.lfs_otstamp);
}
}
/*
* Verify the checkpoint of the newer superblock,
* if the timestamp of the two superblocks is
* different. XXX use lfs_offset instead, discover
* how to quickly discover "newness" based on that.
*/
if ((sb0->lfs_version == 1 &&
sb0->lfs_otstamp != sb1->lfs_otstamp) ||
(sb0->lfs_version > 1 &&
sb0->lfs_serial != sb1->lfs_serial)) {
if (sb0->lfs_version == 1) {
if (sb0->lfs_otstamp > sb1->lfs_otstamp) {
osb = sb1;
nsb = sb0;
} else {
osb = sb0;
nsb = sb1;
}
} else {
if (sb0->lfs_serial > sb1->lfs_serial) {
osb = sb1;
nsb = sb0;
} else {
osb = sb0;
nsb = sb1;
}
}
daddr = try_verify(osb, nsb);
if (debug)
printf("done.\n");
if (daddr == nsb->lfs_offset) {
pwarn("Checkpoint verified, recovered %lld seconds of data\n",
(long long)nsb->lfs_tstamp - (long long)osb->lfs_tstamp);
memcpy(&sblock, nsb, sizeof(*nsb));
sbdirty();
} else {
pwarn("Checkpoint invalid, lost %lld seconds of data\n", (long long)nsb->lfs_tstamp - (long long)osb->lfs_tstamp);
memcpy(&sblock, osb, sizeof(*osb));
}
}
}
free(sb0);
free(sb1);
}
if (idaddr == 0x0)
idaddr = sblock.lfs_idaddr;
if (debug) {
printf("dev_bsize = %lu\n", dev_bsize);
printf("lfs_bsize = %lu\n", (unsigned long)sblock.lfs_bsize);
printf("lfs_fsize = %lu\n", (unsigned long)sblock.lfs_fsize);
printf("lfs_frag = %lu\n", (unsigned long)sblock.lfs_frag);
printf("INOPB(fs) = %lu\n", (unsigned long)INOPB(&sblock));
if (sblock.lfs_version > 1)
printf("INOPF(fs) = %lu\n",
(unsigned long)INOPF(&sblock));
/* printf("fsbtodb(fs,1) = %lu\n",fsbtodb(&sblock,1)); */
}
/* Compatibility */
if (sblock.lfs_version == 1) {
sblock.lfs_sumsize = LFS_V1_SUMMARY_SIZE;
sblock.lfs_ibsize = sblock.lfs_bsize;
sblock.lfs_start = sblock.lfs_sboffs[0];
sblock.lfs_fsbtodb = 0;
}
initbarea(&iblk);
iblk.b_un.b_buf = malloc(sblock.lfs_ibsize);
if (bread(fsreadfd, (char *)iblk.b_un.b_buf, fsbtodb(&sblock, idaddr),
(long)sblock.lfs_ibsize) != 0) {
printf("Couldn't read disk block %d\n", idaddr);
exit(1);
}
idinode = lfs_difind(&sblock, sblock.lfs_ifile, &ifblock);
if (idinode == NULL) {
printf("Ifile inode not found at daddr 0x%x\n", idaddr);
exit(1);
/* XXX find it in the segment summaries */
}
maxino = ((idinode->di_size
- (sblock.lfs_cleansz + sblock.lfs_segtabsz) * sblock.lfs_bsize)
/ sblock.lfs_bsize) * sblock.lfs_ifpb;
if (debug)
printf("maxino = %d\n", maxino);
din_table = (daddr_t *)malloc(maxino * sizeof(*din_table));
memset(din_table, 0, maxino * sizeof(*din_table));
seg_table = (SEGUSE *)malloc(sblock.lfs_nseg * sizeof(SEGUSE));
memset(seg_table, 0, sblock.lfs_nseg * sizeof(SEGUSE));
if (sblock.lfs_version == 1)
maxfsblock = sblock.lfs_size * (sblock.lfs_bsize / dev_bsize);
else
maxfsblock = sblock.lfs_size;
maxfilesize = maxtable[sblock.lfs_bshift] << sblock.lfs_bshift;
if ((sblock.lfs_minfree < 0 || sblock.lfs_minfree > 99)) {
pfatal("IMPOSSIBLE MINFREE=%d IN SUPERBLOCK",
sblock.lfs_minfree);
if (reply("SET TO DEFAULT") == 1) {
sblock.lfs_minfree = 10;
sbdirty();
}
}
if (sblock.lfs_bmask != sblock.lfs_bsize - 1) {
pwarn("INCORRECT BMASK=%x IN SUPERBLOCK (should be %x)",
(unsigned int)sblock.lfs_bmask,
(unsigned int)sblock.lfs_bsize - 1);
sblock.lfs_bmask = sblock.lfs_bsize - 1;
if (preen)
printf(" (FIXED)\n");
if (preen || reply("FIX") == 1) {
sbdirty();
dirty(&asblk);
}
}
#if 0 /* FFS-specific checks */
if (sblock.lfs_fmask != ~(sblock.lfs_fsize - 1)) {
pwarn("INCORRECT FMASK=%x IN SUPERBLOCK",
sblock.lfs_fmask);
sblock.lfs_fmask = ~(sblock.lfs_fsize - 1);
if (preen)
printf(" (FIXED)\n");
if (preen || reply("FIX") == 1) {
sbdirty();
dirty(&asblk);
}
}
#endif
if (sblock.lfs_maxfilesize != maxfilesize) {
pwarn(
"INCORRECT MAXFILESIZE=%llu IN SUPERBLOCK (should be %llu)",
(unsigned long long)sblock.lfs_maxfilesize,
(unsigned long long)maxfilesize);
sblock.lfs_maxfilesize = maxfilesize;
if (preen)
printf(" (FIXED)\n");
if (preen || reply("FIX") == 1) {
sbdirty();
dirty(&asblk);
}
}
if (sblock.lfs_maxsymlinklen != MAXSYMLINKLEN) {
pwarn("INCORRECT MAXSYMLINKLEN=%d IN SUPERBLOCK",
sblock.lfs_maxsymlinklen);
sblock.lfs_maxsymlinklen = MAXSYMLINKLEN;
if (preen)
printf(" (FIXED)\n");
if (preen || reply("FIX") == 1) {
sbdirty();
dirty(&asblk);
}
}
newinofmt = 1;
/*
* allocate and initialize the necessary maps
*/
#ifndef VERBOSE_BLOCKMAP
bmapsize = roundup(howmany(maxfsblock, NBBY), sizeof(int16_t));
blockmap = calloc((unsigned)bmapsize, sizeof(char));
#else
bmapsize = maxfsblock * sizeof(ino_t);
blockmap = (ino_t *)calloc(maxfsblock, sizeof(ino_t));
#endif
if (blockmap == NULL) {
printf("cannot alloc %u bytes for blockmap\n",
(unsigned)bmapsize);
goto badsblabel;
}
statemap = calloc((unsigned)maxino, sizeof(char));
if (statemap == NULL) {
printf("cannot alloc %u bytes for statemap\n",
(unsigned)maxino);
goto badsblabel;
}
typemap = calloc((unsigned)maxino, sizeof(char));
if (typemap == NULL) {
printf("cannot alloc %u bytes for typemap\n",
(unsigned)maxino);
goto badsblabel;
}
lncntp = (int16_t *)calloc((unsigned)maxino, sizeof(int16_t));
if (lncntp == NULL) {
printf("cannot alloc %lu bytes for lncntp\n",
(unsigned long)maxino * sizeof(int16_t));
goto badsblabel;
}
return (1);
badsblabel:
ckfini(0);
return (0);
}
/*
* Read in the LFS super block and its summary info.
*/
static int
readsb(int listerr)
{
daddr_t super = bflag ? bflag : LFS_LABELPAD / dev_bsize;
u_int32_t checksum;
if (bread(fsreadfd, (char *) &sblock, super, (long) LFS_SBPAD) != 0)
return (0);
sblk.b_bno = super;
sblk.b_size = LFS_SBPAD;
/*
* run a few consistency checks of the super block
*/
if (sblock.lfs_magic != LFS_MAGIC) {
badsb(listerr, "MAGIC NUMBER WRONG");
return (0);
}
/* checksum */
checksum = lfs_sb_cksum(&(sblock.lfs_dlfs));
if (sblock.lfs_cksum != checksum) {
printf("Superblock checksum (%lu)does not match computed checksum %lu\n",
(unsigned long)sblock.lfs_cksum, (unsigned long) checksum);
}
#if 0 /* XXX - replace these checks with
* appropriate LFS sanity checks */
if (sblock.lfs_ncg < 1) {
badsb(listerr, "NCG OUT OF RANGE");
return (0);
}
if (sblock.lfs_cpg < 1) {
badsb(listerr, "CPG OUT OF RANGE");
return (0);
}
if (sblock.lfs_ncg * sblock.lfs_cpg < sblock.lfs_ncyl ||
(sblock.lfs_ncg - 1) * sblock.lfs_cpg >= sblock.lfs_ncyl) {
badsb(listerr, "NCYL LESS THAN NCG*CPG");
return (0);
}
if (sblock.lfs_sbsize > SBSIZE) {
badsb(listerr, "SIZE PREPOSTEROUSLY LARGE");
return (0);
}
#endif
/*
* Compute block size that the filesystem is based on,
* according to fsbtodb, and adjust superblock block number
* so we can tell if this is an alternate later.
*/
super *= dev_bsize;
#if 0
dev_bsize = sblock.lfs_bsize / fsbtodb(&sblock, 1);
#endif
sblk.b_bno = super / dev_bsize;
if (bflag) {
havesb = 1;
return (1);
}
#if 0 /* XXX - for now skip the alt. superblock
* test as well */
/*
* Set all possible fields that could differ, then do check
* of whole super block against an alternate super block.
* When an alternate super-block is specified this check is skipped.
*/
getblk(&asblk, cgsblock(&sblock, sblock.lfs_ncg - 1), sblock.lfs_sbsize);
if (asblk.b_errs)
return (0);
altsblock.lfs_firstfield = sblock.lfs_firstfield;
altsblock.lfs_fscktime = sblock.lfs_fscktime;
altsblock.lfs_time = sblock.lfs_time;
altsblock.lfs_cstotal = sblock.lfs_cstotal;
altsblock.lfs_cgrotor = sblock.lfs_cgrotor;
altsblock.lfs_fmod = sblock.lfs_fmod;
altsblock.lfs_clean = sblock.lfs_clean;
altsblock.lfs_ronly = sblock.lfs_ronly;
altsblock.lfs_flags = sblock.lfs_flags;
altsblock.lfs_maxcontig = sblock.lfs_maxcontig;
altsblock.lfs_minfree = sblock.lfs_minfree;
altsblock.lfs_optim = sblock.lfs_optim;
altsblock.lfs_rotdelay = sblock.lfs_rotdelay;
altsblock.lfs_maxbpg = sblock.lfs_maxbpg;
memcpy(altsblock.lfs_csp, sblock.lfs_csp,
sizeof sblock.lfs_csp);
altsblock.lfs_maxcluster = sblock.lfs_maxcluster;
memcpy(altsblock.lfs_fsmnt, sblock.lfs_fsmnt,
sizeof sblock.lfs_fsmnt);
memcpy(altsblock.lfs_sparecon, sblock.lfs_sparecon,
sizeof sblock.lfs_sparecon);
/*
* The following should not have to be copied.
*/
altsblock.lfs_fsbtodb = sblock.lfs_fsbtodb;
altsblock.lfs_interleave = sblock.lfs_interleave;
altsblock.lfs_npsect = sblock.lfs_npsect;
altsblock.lfs_nrpos = sblock.lfs_nrpos;
altsblock.lfs_state = sblock.lfs_state;
altsblock.lfs_qbmask = sblock.lfs_qbmask;
altsblock.lfs_qfmask = sblock.lfs_qfmask;
altsblock.lfs_state = sblock.lfs_state;
altsblock.lfs_maxfilesize = sblock.lfs_maxfilesize;
if (memcmp(&sblock, &altsblock, (int)sblock.lfs_sbsize)) {
if (debug) {
long *nlp, *olp, *endlp;
printf("superblock mismatches\n");
nlp = (long *) &altsblock;
olp = (long *) &sblock;
endlp = olp + (sblock.lfs_sbsize / sizeof *olp);
for (; olp < endlp; olp++, nlp++) {
if (*olp == *nlp)
continue;
printf("offset %d, original %ld, alternate %ld\n",
olp - (long *) &sblock, *olp, *nlp);
}
}
badsb(listerr,
"VALUES IN SUPER BLOCK DISAGREE WITH THOSE IN FIRST ALTERNATE");
return (0);
}
#endif
havesb = 1;
return (1);
}
void
badsb(int listerr, char *s)
{
if (!listerr)
return;
if (preen)
printf("%s: ", cdevname());
pfatal("BAD SUPER BLOCK: %s\n", s);
}
/*
* Calculate a prototype superblock based on information in the disk label.
* When done the cgsblock macro can be calculated and the fs_ncg field
* can be used. Do NOT attempt to use other macros without verifying that
* their needed information is available!
*/
int
calcsb(const char *dev, int devfd, struct lfs * fs)
{
register struct disklabel *lp;
register struct partition *pp;
register char *cp;
int i;
cp = strchr(dev, '\0') - 1;
if ((cp == (char *) -1 || (*cp < 'a' || *cp > 'h')) && !isdigit(*cp)) {
pfatal("%s: CANNOT FIGURE OUT FILE SYSTEM PARTITION\n", dev);
return (0);
}
lp = getdisklabel(dev, devfd);
if (lp == NULL) {
dev_bsize = DEV_BSIZE;
} else {
if (isdigit(*cp))
pp = &lp->d_partitions[0];
else
pp = &lp->d_partitions[*cp - 'a'];
if (pp->p_fstype != FS_BSDLFS) {
pfatal("%s: NOT LABELED AS AN LFS FILE SYSTEM (%s)\n",
dev, pp->p_fstype < FSMAXTYPES ?
fstypenames[pp->p_fstype] : "unknown");
return (0);
}
memset(fs, 0, sizeof(struct lfs));
fs->lfs_fsize = pp->p_fsize;
fs->lfs_frag = pp->p_frag;
fs->lfs_size = pp->p_size;
fs->lfs_nspf = fs->lfs_fsize / lp->d_secsize;
dev_bsize = lp->d_secsize;
for (fs->lfs_fsbtodb = 0, i = fs->lfs_nspf; i > 1; i >>= 1)
fs->lfs_fsbtodb++;
}
return (1);
}
static struct disklabel *
getdisklabel(const char *s, int fd)
{
static struct disklabel lab;
if (ioctl(fd, DIOCGDINFO, (char *) &lab) < 0) {
if (s == NULL)
return ((struct disklabel *) NULL);
pwarn("ioctl (GCINFO): %s\n", strerror(errno));
#if 0
errexit("%s: can't read disk label\n", s);
#else
return NULL;
#endif
}
return (&lab);
}