freebsd-dev/sys/kern/subr_diskmbr.c
1994-12-30 12:19:11 +00:00

213 lines
6.2 KiB
C

/*-
* Copyright (c) 1994 Bruce D. Evans.
* All rights reserved.
*
* Copyright (c) 1982, 1986, 1988 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.
*
* from: @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91
* from: ufs_disksubr.c,v 1.8 1994/06/07 01:21:39 phk Exp $
* $Id:
*/
#include <stddef.h>
#include <sys/param.h>
#include <sys/buf.h>
#include <sys/disklabel.h>
#include <sys/diskslice.h>
#include <sys/malloc.h>
#include <sys/systm.h>
int
dsinit(dname, dev, strat, lp, sspp)
char *dname;
dev_t dev;
d_strategy_t *strat;
struct disklabel *lp;
struct diskslices **sspp;
{
struct buf *bp;
u_char *cp;
struct dos_partition *dp;
struct dos_partition *dp0;
int error;
int max_nsectors;
int max_ntracks;
u_long secpercyl;
int slice;
struct diskslice *sp;
struct diskslices *ssp;
/*
* Free old slices "struct", if any, and allocate a dummy new one.
*/
if (*sspp != NULL)
free(*sspp, M_DEVBUF);
ssp = malloc(offsetof(struct diskslices, dss_slices) + sizeof(*sp),
M_DEVBUF, M_WAITOK);
*sspp = ssp;
/*
* Initialize dummy slice. If there is an error, this becomes the
* only slice, and no more restrictive than the (dummy) label.
*/
sp = &ssp->dss_slices[0];
bzero(sp, sizeof *sp);
sp->ds_size = lp->d_secperunit;
ssp->dss_nslices = 1;
/* Read master boot record. */
bp = geteblk((int)lp->d_secsize);
bp->b_dev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
bp->b_blkno = DOSBBSECTOR;
bp->b_bcount = lp->d_secsize;
bp->b_flags = B_BUSY | B_READ;
(*strat)(bp);
if (biowait(bp) != 0) {
error = EIO;
goto done;
}
/* Weakly verify it. */
cp = bp->b_un.b_addr;
if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) {
error = EINVAL;
goto done;
}
/* Guess the geometry. */
/*
* TODO:
* Perhaps skip entries with 0 size.
* Perhaps only look at entries of type DOSPTYP_386BSD.
*/
max_nsectors = 0;
max_ntracks = 0;
dp0 = (struct dos_partition *)(cp + DOSPARTOFF);
for (dp = dp0, slice = 1; slice <= NDOSPART; dp++, slice++) {
int nsectors;
int ntracks;
nsectors = DPSECT(dp->dp_esect);
if (max_nsectors < nsectors)
max_nsectors = nsectors;
ntracks = dp->dp_ehd + 1;
if (max_ntracks < ntracks)
max_ntracks = ntracks;
}
/* Check the geometry. */
/*
* TODO:
* As above.
* Check for overlaps.
* Check or adjust against d_ncylinders and d_secperunit.
*/
error = 0;
secpercyl = max_nsectors * max_ntracks;
for (dp = dp0, slice = 1; slice <= NDOSPART; dp++, slice++) {
u_long esector;
u_long esector1;
u_long ssector;
if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0
&& dp->dp_start == 0 && dp->dp_size == 0)
continue;
ssector = DPSECT(dp->dp_ssect) - 1 + dp->dp_shd * max_nsectors
+ DPCYL(dp->dp_scyl, dp->dp_ssect) * secpercyl;
esector = DPSECT(dp->dp_esect) - 1 + dp->dp_ehd * max_nsectors
+ DPCYL(dp->dp_ecyl, dp->dp_esect) * secpercyl;
esector1 = dp->dp_start + dp->dp_size - 1;
if (ssector != dp->dp_start || esector != esector1)
error = EINVAL;
#if 1
else
printf("%s%ds%d: start %lu, end = %lu, size %lu: OK\n",
dname, dkunit(dev), slice, ssector, esector,
dp->dp_size);
if (ssector != dp->dp_start)
printf(
"%s%ds%d: C/H/S start %lu != start %lu: invalid\n",
dname, dkunit(dev), slice, ssector,
dp->dp_start);
if (esector != esector1)
printf(
"%s%ds%d: C/H/S end %lu != end %lu: invalid\n",
dname, dkunit(dev), slice, esector, esector1);
#endif
}
if (error != 0)
goto done;
/*
* We're not handling extended partitions yet, so there are always
* 1 + NDOSPART slices.
*/
if (dkslice(dev) >= 1 + NDOSPART) {
error = ENXIO;
goto done;
}
/*
* Accept the DOS partition table.
* Free dummy slices "struct" and allocate a real new one.
*/
free(ssp, M_DEVBUF);
ssp = malloc(offsetof(struct diskslices, dss_slices)
+ (1 + NDOSPART) * sizeof(*sp), M_DEVBUF, M_WAITOK);
*sspp = ssp;
sp = &ssp->dss_slices[0];
bzero(sp, (1 + NDOSPART) * sizeof *sp);
sp->ds_size = lp->d_secperunit;
sp++;
for (dp = dp0, slice = 1; slice <= NDOSPART; dp++, slice++, sp++) {
sp->ds_offset = dp->dp_start;
sp->ds_size = dp->dp_size;
}
ssp->dss_nslices = 1 + NDOSPART;
if (max_nsectors != 0) {
lp->d_nsectors = max_nsectors;
lp->d_ntracks = max_ntracks;
lp->d_secpercyl = secpercyl;
}
#if 0
lp->d_secperunit = what?;
lp->d_subtype |= (lp->d_subtype & 3) + (slice - 1) | DSTYPE_INDOSPART;
#endif
done:
bp->b_flags = B_INVAL | B_AGE;
brelse(bp);
if (error == EINVAL)
error = (dkslice(dev) == WHOLE_DISK_SLICE ? 0 : ENXIO);
return (error);
}