/* $OpenBSD: disksubr.c,v 1.36 2007/06/20 18:15:45 deraadt Exp $ */
/* $NetBSD: disksubr.c,v 1.21 1996/05/03 19:42:03 christos Exp $ */
/*
* Copyright (c) 1996 Theo de Raadt
* 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. 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.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/disklabel.h>
#include <sys/disk.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, secsize and anything required for a block i/o read
* operation in the driver's strategy/start routines
* must be filled in before calling us.
*
* If dos partition table requested, attempt to load it and
* find disklabel inside a DOS partition. Return buffer
* for use in signalling errors if requested.
*
* We would like to check if each MBR has a valid DOSMBR_SIGNATURE, but
* we cannot because it doesn't always exist. So.. we assume the
* MBR is valid.
*
* Returns null on success and an error string on failure.
*/
char *
readdisklabel(dev_t dev, void (*strat)(struct buf *),
struct disklabel *lp, int spoofonly)
{
struct buf *bp = NULL;
char *msg;
if ((msg = initdisklabel(lp)))
goto done;
/* get a buffer and initialize it */
bp = geteblk((int)lp->d_secsize);
bp->b_dev = dev;
msg = readdoslabel(bp, strat, lp, NULL, spoofonly);
if (msg == NULL)
goto done;
#if defined(CD9660)
if (iso_disklabelspoof(dev, strat, lp) == 0) {
msg = NULL;
goto done;
}
#endif
#if defined(UDF)
if (udf_disklabelspoof(dev, strat, lp) == 0) {
msg = NULL;
goto done;
}
#endif
done:
if (bp) {
bp->b_flags |= B_INVAL;
brelse(bp);
}
return (msg);
}
/*
* Write disk label back to device after modification.
*/
int
writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp)
{
int error = EIO, partoff = -1;
struct disklabel *dlp;
struct buf *bp = NULL;
/* get a buffer and initialize it */
bp = geteblk((int)lp->d_secsize);
bp->b_dev = dev;
if (readdoslabel(bp, strat, lp, &partoff, 1) != NULL)
goto done;
/* Read it in, slap the new label in, and write it back out */
bp->b_blkno = partoff + LABELSECTOR;
bp->b_bcount = lp->d_secsize;
bp->b_flags = B_BUSY | B_READ;
(*strat)(bp);
if ((error = biowait(bp)) != 0)
goto done;
dlp = (struct disklabel *)(bp->b_data + LABELOFFSET);
*dlp = *lp;
bp->b_flags = B_BUSY | B_WRITE;
(*strat)(bp);
error = biowait(bp);
done:
if (bp) {
bp->b_flags |= B_INVAL;
brelse(bp);
}
return (error);
}