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/* $OpenBSD: disksubr.c,v 1.29 2007/06/02 02:35:26 krw Exp $ */
/* $NetBSD: disksubr.c,v 1.9 1997/04/01 03:12:13 scottr Exp $ */
/*
* Copyright (c) 1982, 1986, 1988, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* 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. 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.
*
* @(#)ufs_disksubr.c 8.5 (Berkeley) 1/21/94
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/disk.h>
#include <sys/disklabel.h>
#include <sys/syslog.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.
*/
char *
readdisklabel(dev, strat, lp, osdep, spoofonly)
dev_t dev;
void (*strat)(struct buf *);
struct disklabel *lp;
struct cpu_disklabel *osdep;
int spoofonly;
{
struct buf *bp = NULL;
struct disklabel *dlp;
int i;
char *msg = NULL;
/* minimal requirements for archetypal disk label */
if (lp->d_secsize < DEV_BSIZE)
lp->d_secsize = DEV_BSIZE;
if (lp->d_secperunit == 0)
lp->d_secperunit = 0x1fffffff;
if (lp->d_secpercyl == 0) {
msg = "invalid geometry";
goto done;
}
lp->d_npartitions = RAW_PART + 1;
for (i = 0; i < RAW_PART; i++) {
lp->d_partitions[i].p_size = 0;
lp->d_partitions[i].p_offset = 0;
}
if (lp->d_partitions[i].p_size == 0)
lp->d_partitions[i].p_size = lp->d_secperunit;
lp->d_partitions[i].p_offset = 0;
/* don't read the on-disk label if we are in spoofed-only mode */
if (spoofonly)
goto done;
bp = geteblk((int)lp->d_secsize);
bp->b_dev = dev;
bp->b_blkno = LABELSECTOR;
bp->b_bcount = lp->d_secsize;
bp->b_flags = B_BUSY | B_READ;
bp->b_cylinder = LABELSECTOR / lp->d_secpercyl;
(*strat)(bp);
if (biowait(bp))
msg = "disk label I/O error";
else for (dlp = (struct disklabel *)bp->b_data;
dlp <= (struct disklabel *)((char *)bp->b_data +
DEV_BSIZE - sizeof(*dlp));
dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) {
if (msg == NULL) {
#if defined(CD9660)
if (iso_disklabelspoof(dev, strat, lp) != 0)
#endif
msg = "no disk label";
#if defined(UDF)
if (msg && udf_disklabelspoof(dev, strat, lp) == 0)
msg = NULL;
#endif
}
} else if (dlp->d_npartitions > MAXPARTITIONS ||
dkcksum(dlp) != 0)
msg = "disk label corrupted";
else {
*lp = *dlp;
msg = NULL;
break;
}
}
done:
if (bp) {
bp->b_flags = B_INVAL | B_AGE;
brelse(bp);
}
disklabeltokernlabel(lp);
return (msg);
}
/*
* Check new disk label for sensibility before setting it.
*/
int
setdisklabel(olp, nlp, openmask, osdep)
struct disklabel *olp, *nlp;
u_long openmask;
struct cpu_disklabel *osdep;
{
int i;
struct partition *opp, *npp;
if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC ||
dkcksum(nlp) != 0)
return (EINVAL);
while ((i = ffs((long)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_fragblock = opp->p_fragblock;
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.
*/
int
writedisklabel(dev, strat, lp, osdep)
dev_t dev;
void (*strat)(struct buf *);
struct disklabel *lp;
struct cpu_disklabel *osdep;
{
struct buf *bp;
struct disklabel *dlp;
int labelpart;
int error = 0;
labelpart = DISKPART(dev);
if (lp->d_partitions[labelpart].p_offset != 0) {
if (lp->d_partitions[0].p_offset != 0)
return (EXDEV); /* not quite right */
labelpart = 0;
}
bp = geteblk((int)lp->d_secsize);
bp->b_dev = MAKEDISKDEV(major(dev), DISKUNIT(dev), labelpart);
bp->b_blkno = LABELSECTOR;
bp->b_bcount = lp->d_secsize;
bp->b_flags = B_READ;
(*strat)(bp);
if ((error = biowait(bp)))
goto done;
for (dlp = (struct disklabel *)bp->b_data;
dlp <= (struct disklabel *)
((char *)bp->b_data + lp->d_secsize - sizeof(*dlp));
dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC &&
dkcksum(dlp) == 0) {
*dlp = *lp;
bp->b_flags = B_WRITE;
(*strat)(bp);
error = biowait(bp);
goto done;
}
}
/* Write it in the regular place. */
*(struct disklabel *)bp->b_data = *lp;
bp->b_flags = B_BUSY | B_WRITE;
(*strat)(bp);
error = biowait(bp);
done:
brelse(bp);
return (error);
}
/*
* Determine the size of the transfer, and make sure it is
* within the boundaries of the partition. Adjust transfer
* if needed, and signal errors or early completion.
*/
int
bounds_check_with_label(struct buf *bp, struct disklabel *lp,
struct cpu_disklabel *osdep, int wlabel)
{
#define blockpersec(count, lp) ((count) * (((lp)->d_secsize) / DEV_BSIZE))
struct partition *p = lp->d_partitions + DISKPART(bp->b_dev);
int labelsector = blockpersec(lp->d_partitions[0].p_offset, lp) +
LABELSECTOR;
int sz = howmany(bp->b_bcount, DEV_BSIZE);
/* avoid division by zero */
if (lp->d_secpercyl == 0) {
bp->b_error = EINVAL;
goto bad;
}
/* Overwriting disk label? */
if (bp->b_blkno + blockpersec(p->p_offset, lp) <= labelsector &&
(bp->b_flags & B_READ) == 0 && !wlabel) {
bp->b_error = EROFS;
goto bad;
}
/* beyond partition? */
if (bp->b_blkno + sz > blockpersec(p->p_size, lp)) {
sz = blockpersec(p->p_size, lp) - bp->b_blkno;
if (sz == 0) {
/* If exactly at end of disk, return EOF. */
bp->b_resid = bp->b_bcount;
return (0);
}
if (sz < 0) {
/* If past end of disk, return EINVAL. */
bp->b_error = EINVAL;
goto bad;
}
/* Otherwise, truncate request. */
bp->b_bcount = sz << DEV_BSHIFT;
}
/* calculate cylinder for disksort to order transfers with */
bp->b_cylinder = (bp->b_blkno + blockpersec(p->p_offset, lp)) /
lp->d_secpercyl;
return (1);
bad:
bp->b_flags |= B_ERROR;
return (-1);
}
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