NetBSD-5.0.2/sys/arch/algor/algor/disksubr.c
/* $NetBSD: disksubr.c,v 1.17 2008/01/02 11:48:20 ad Exp $ */
/*
* Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
* All rights reserved.
*
* Authors: Keith Bostic, Chris G. Demetriou
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
__KERNEL_RCSID(0, "$NetBSD: disksubr.c,v 1.17 2008/01/02 11:48:20 ad Exp $");
#include <sys/param.h>
#include <sys/buf.h>
#include <sys/ioccom.h>
#include <sys/device.h>
#include <sys/disklabel.h>
#include <sys/disk.h>
#include <sys/systm.h>
#include <machine/cpu.h>
#include <machine/autoconf.h>
/*
* Attempt to read a disk label from a device
* using the indicated strategy routine.
* The label must be partly set up before this:
* secpercyl and anything required in the strategy routine
* (e.g., sector size) must be filled in before calling us.
* Returns null on success and an error string on failure.
*/
const char *
readdisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp,
struct cpu_disklabel *clp)
{
struct buf *bp;
struct disklabel *dlp;
struct dkbad *bdp;
const char *msg = NULL;
int i;
/* minimal requirements for archtypal disk label */
if (lp->d_secsize == 0)
lp->d_secsize = DEV_BSIZE;
if (lp->d_secperunit == 0)
lp->d_secperunit = 0x1fffffff;
lp->d_npartitions = RAW_PART + 1;
if (lp->d_partitions[RAW_PART].p_size == 0)
lp->d_partitions[RAW_PART].p_size = lp->d_secperunit;
lp->d_partitions[RAW_PART].p_offset = 0;
/* obtain buffer to probe drive with */
bp = geteblk((int)lp->d_secsize);
/* next, dig out disk label */
bp->b_dev = dev;
bp->b_blkno = LABELSECTOR;
bp->b_cylinder = 0;
bp->b_bcount = lp->d_secsize;
bp->b_flags |= B_READ;
(*strat)(bp);
/* if successful, locate disk label within block and validate */
if (biowait(bp)) {
msg = "disk label read error";
goto done;
}
dlp = (struct disklabel *)((char*)bp->b_data + LABELOFFSET);
if (dlp->d_magic == DISKMAGIC) {
if (dkcksum(dlp))
msg = "NetBSD disk label corrupted";
else
*lp = *dlp;
} else
msg = "no disk label";
if (msg)
goto done;
/* obtain bad sector table if requested and present */
if (clp && (bdp = &clp->bad) != NULL && (lp->d_flags & D_BADSECT)) {
struct dkbad *db;
i = 0;
do {
/* read a bad sector table */
bp->b_oflags &= ~(BO_DONE);
bp->b_flags |= B_READ;
bp->b_blkno = lp->d_secperunit - lp->d_nsectors + i;
if (lp->d_secsize > DEV_BSIZE)
bp->b_blkno *= lp->d_secsize / DEV_BSIZE;
else
bp->b_blkno /= DEV_BSIZE / lp->d_secsize;
bp->b_bcount = lp->d_secsize;
bp->b_cylinder = lp->d_ncylinders - 1;
(*strat)(bp);
/* if successful, validate, otherwise try another */
if (biowait(bp)) {
msg = "bad sector table I/O error";
} else {
db = (struct dkbad *)(bp->b_data);
#define DKBAD_MAGIC 0x4321
if (db->bt_mbz == 0
&& db->bt_flag == DKBAD_MAGIC) {
msg = NULL;
*bdp = *db;
break;
} else
msg = "bad sector table corrupted";
}
} while (bp->b_error != 0 && (i += 2) < 10 &&
i < lp->d_nsectors);
}
done:
brelse(bp, 0);
return (msg);
}
/*
* Check new disk label for sensibility before setting it.
*/
int
setdisklabel(struct disklabel *olp, struct disklabel *nlp, u_long openmask,
struct cpu_disklabel *clp)
{
int i;
struct partition *opp, *npp;
/* sanity clause */
if (nlp->d_secpercyl == 0 || nlp->d_secsize == 0 ||
(nlp->d_secsize % DEV_BSIZE) != 0)
return(EINVAL);
#ifdef notdef
/* XXX WHY WAS THIS HERE?! */
/* special case to allow disklabel to be invalidated */
if (nlp->d_magic == 0xffffffff) {
*olp = *nlp;
return (0);
}
#endif
if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC ||
dkcksum(nlp) != 0)
return (EINVAL);
while ((i = ffs(openmask)) != 0) {
i--;
openmask &= ~(1 << i);
if (nlp->d_npartitions <= i)
return (EBUSY);
opp = &olp->d_partitions[i];
npp = &nlp->d_partitions[i];
if (npp->p_offset != opp->p_offset || npp->p_size < opp->p_size)
return (EBUSY);
/*
* Copy internally-set partition information
* if new label doesn't include it. XXX
*/
if (npp->p_fstype == FS_UNUSED && opp->p_fstype != FS_UNUSED) {
npp->p_fstype = opp->p_fstype;
npp->p_fsize = opp->p_fsize;
npp->p_frag = opp->p_frag;
npp->p_cpg = opp->p_cpg;
}
}
nlp->d_checksum = 0;
nlp->d_checksum = dkcksum(nlp);
*olp = *nlp;
return (0);
}
/*
* Write disk label back to device after modification.
* this means write out the Rigid disk blocks to represent the
* label. Hope the user was carefull.
*/
int
writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp,
struct cpu_disklabel *clp)
{
struct buf *bp;
struct disklabel *dlp;
int error = 0;
bp = geteblk((int)lp->d_secsize);
bp->b_dev = dev;
bp->b_blkno = LABELSECTOR;
bp->b_cylinder = 0;
bp->b_bcount = lp->d_secsize;
bp->b_flags |= B_READ; /* get current label */
(*strat)(bp);
if ((error = biowait(bp)) != 0)
goto done;
dlp = (struct disklabel *)((char*)bp->b_data + LABELOFFSET);
*dlp = *lp; /* struct assignment */
bp->b_oflags &= ~(BO_DONE);
bp->b_flags &= ~(B_READ);
bp->b_flags |= B_WRITE;
(*strat)(bp);
error = biowait(bp);
done:
brelse(bp, 0);
return (error);
}