NetBSD/sys/arch/alpha/alpha/disksubr.c
chs c62d17a551 rationalize the use of b_flags for geteblk() buffers.
rather than assigning to the whole field, set or clear individual flags,
which implies that the B_BUSY and B_INVAL flags will remain set.
this allows us to make the assertion in brelse() that B_BUSY is set,
which is the purpose of all this.
2000-11-20 08:24:08 +00:00

309 lines
7.7 KiB
C

/* $NetBSD: disksubr.c,v 1.21 2000/11/20 08:24:08 chs 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 1.21 2000/11/20 08:24:08 chs 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 <dev/scsipi/scsi_all.h>
#include <dev/scsipi/scsipi_all.h>
#include <dev/scsipi/scsiconf.h>
#include <machine/cpu.h>
#include <machine/autoconf.h>
extern struct device *bootdv;
/*
* Attempt to read a disk label from a device
* using the indicated stategy 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, clp)
dev_t dev;
void (*strat) __P((struct buf *));
struct disklabel *lp;
struct cpu_disklabel *clp;
{
struct buf *bp;
struct disklabel *dlp;
struct dkbad *bdp;
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_secsize / DEV_BSIZE);
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 *)(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_flags &= ~(B_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_flags & B_ERROR) && (i += 2) < 10 &&
i < lp->d_nsectors);
}
done:
brelse(bp);
return (msg);
}
/*
* Check new disk label for sensibility before setting it.
*/
int
setdisklabel(olp, nlp, openmask, clp)
struct disklabel *olp, *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((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_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, strat, lp, clp)
dev_t dev;
void (*strat) __P((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 *)(bp->b_data + LABELOFFSET);
*dlp = *lp; /* struct assignment */
/*
* The Alpha requires that the boot block be checksummed.
* The first 63 8-bit quantites are summed into the 64th.
*/
{
int i;
u_long *dp, sum;
dp = (u_long *)bp->b_data;
sum = 0;
for (i = 0; i < 63; i++)
sum += dp[i];
dp[63] = sum;
}
bp->b_flags &= ~(B_READ|B_DONE);
bp->b_flags |= 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(bp, lp, wlabel)
struct buf *bp;
struct disklabel *lp;
int wlabel;
{
struct partition *p = lp->d_partitions + DISKPART(bp->b_dev);
int labelsect = lp->d_partitions[RAW_PART].p_offset;
int maxsz = p->p_size;
int sz = (bp->b_bcount + DEV_BSIZE - 1) >> DEV_BSHIFT;
/* overwriting disk label ? */
/* XXX should also protect bootstrap in first 8K */
if (bp->b_blkno + p->p_offset <= LABELSECTOR + labelsect &&
(bp->b_flags & B_READ) == 0 && wlabel == 0) {
bp->b_error = EROFS;
goto bad;
}
/* beyond partition? */
if (bp->b_blkno < 0 || bp->b_blkno + sz > maxsz) {
/* if exactly at end of disk, return an EOF */
if (bp->b_blkno == maxsz) {
bp->b_resid = bp->b_bcount;
return(0);
}
/* or truncate if part of it fits */
sz = maxsz - bp->b_blkno;
if (sz <= 0) {
bp->b_error = EINVAL;
goto bad;
}
bp->b_bcount = sz << DEV_BSHIFT;
}
/* calculate cylinder for disksort to order transfers with */
bp->b_resid = (bp->b_blkno + p->p_offset) / lp->d_secpercyl;
return(1);
bad:
bp->b_flags |= B_ERROR;
return(-1);
}