freebsd-skq/sys/kern/subr_diskmbr.c
bde 4e75b5962c Add compatibility cruft.
Slice 0 is now for the first BSD slice.  The first BSD slice is
the first DOSpartition with id 0xa5 or the whole disk if their
are no DOSpartitions (except the latter is not yet implemented).
Existing partitions on it work the same as in 2.0 except the
'd' partition is no longer special and partitions are relative
to the skice.

Slice 1 is now for the whole disk and gets a read-only label
describing the disk.  Previously, slice 0 was for the whole disk
and there was no label on it.

Slices 2-31 are for DOSpartitions.  Slice 0 is an alias for one
of these if there is a BSD slice.  Previously, slices 1-31 were
for DOSpartitions.

diskslice_machdep.c:
Expand whole disk slice to include all DOSpartitions.  More work
is required for >1024 cylinders and to rewrite the label iff the
driver is unsure about the geometry.

subr_diskslice.c:
New function dsisopen() to help handle media changes.
1995-02-16 15:19:19 +00:00

237 lines
7.2 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: diskslice_machdep.c,v 1.3 1995/01/23 02:31:53 phk Exp $
*/
#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_ncyls;
int max_nsectors;
int max_ntracks;
u_long secpercyl;
int slice;
struct diskslice *sp;
struct diskslices *ssp;
/*
* Allocate a dummy slices "struct" and initialize it to contain
* only an empty compatibility slice (pointing to itself) and a
* whole disk slice (which may be a dummy if the label is a dummy).
* If there is an error, then these slices become the only slices.
*/
ssp = malloc(offsetof(struct diskslices, dss_slices)
+ BASE_SLICE * sizeof *sp, M_DEVBUF, M_WAITOK);
*sspp = ssp;
ssp->dss_first_bsd_slice = COMPATIBILITY_SLICE;
ssp->dss_nslices = BASE_SLICE;
sp = &ssp->dss_slices[0];
bzero(sp, BASE_SLICE * sizeof *sp);
sp[WHOLE_DISK_SLICE].ds_size = lp->d_secperunit;
/* 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_ncyls = 0;
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;
max_ncyls = DPCYL(dp->dp_ecyl, dp->dp_esect);
if (max_ncyls < max_ncyls)
max_ncyls = max_ncyls;
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 against d_secperunit if the latter is reliable.
*/
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
* BASE_SLICE + NDOSPART slices.
*/
if (dkslice(dev) >= BASE_SLICE + NDOSPART) {
error = ENXIO;
goto done;
}
/*
* Accept the DOS partition table.
* First adjust the label (we have been careful not to change it
* before we can guarantee success).
*/
if (secpercyl != 0) {
u_long secperunit;
lp->d_nsectors = max_nsectors;
lp->d_ntracks = max_ntracks;
lp->d_secpercyl = secpercyl;
secperunit = secpercyl * max_ncyls;
if (lp->d_secperunit < secperunit)
lp->d_secperunit = secperunit;
}
/*
* Free the dummy slices "struct" and allocate a real new one.
* Initialize special slices as above.
*/
free(ssp, M_DEVBUF);
ssp = malloc(offsetof(struct diskslices, dss_slices)
+ (BASE_SLICE + NDOSPART) * sizeof *sp,
M_DEVBUF, M_WAITOK);
*sspp = ssp;
ssp->dss_first_bsd_slice = COMPATIBILITY_SLICE;
ssp->dss_nslices = BASE_SLICE + NDOSPART;
sp = &ssp->dss_slices[0];
bzero(sp, (BASE_SLICE + NDOSPART) * sizeof *sp);
sp[WHOLE_DISK_SLICE].ds_size = lp->d_secperunit;
/* Initialize normal slices. */
sp += BASE_SLICE;
for (dp = dp0, slice = 1; slice <= NDOSPART; dp++, slice++, sp++) {
if (dp->dp_typ == DOSPTYP_386BSD
&& ssp->dss_first_bsd_slice == COMPATIBILITY_SLICE) {
ssp->dss_first_bsd_slice = BASE_SLICE + slice - 1;
ssp->dss_slices[COMPATIBILITY_SLICE].ds_offset
= dp->dp_start;
ssp->dss_slices[COMPATIBILITY_SLICE].ds_size
= dp->dp_size;
}
sp->ds_offset = dp->dp_start;
sp->ds_size = dp->dp_size;
#if 0
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);
}