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freebsd-skq/sys/kern/subr_disklabel.c

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#define PRE_DISKSLICE_COMPAT
#ifndef PRE_DISKSLICE_COMPAT
#define correct_readdisklabel readdisklabel
#define correct_writedisklabel writedisklabel
#endif
/*
* 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. 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.
*
* @(#)ufs_disksubr.c 8.5 (Berkeley) 1/21/94
* $Id: ufs_disksubr.c,v 1.9 1995/02/16 14:47:38 bde Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/disklabel.h>
#include <sys/diskslice.h>
#include <sys/dkbad.h>
#include <sys/syslog.h>
/*
* Seek sort for disks. We depend on the driver which calls us using b_resid
* as the current cylinder number.
*
* The argument ap structure holds a b_actf activity chain pointer on which we
* keep two queues, sorted in ascending cylinder order. The first queue holds
* those requests which are positioned after the current cylinder (in the first
* request); the second holds requests which came in after their cylinder number
* was passed. Thus we implement a one way scan, retracting after reaching the
* end of the drive to the first request on the second queue, at which time it
* becomes the first queue.
*
* A one-way scan is natural because of the way UNIX read-ahead blocks are
* allocated.
*/
/*
* For portability with historic industry practice, the
* cylinder number has to be maintained in the `b_resid'
* field.
*/
#define b_cylinder b_resid
void
disksort(ap, bp)
register struct buf *ap, *bp;
{
register struct buf *bq;
/* If the queue is empty, then it's easy. */
if (ap->b_actf == NULL) {
bp->b_actf = NULL;
ap->b_actf = bp;
return;
}
/*
* If we lie after the first (currently active) request, then we
* must locate the second request list and add ourselves to it.
*/
bq = ap->b_actf;
if (bp->b_cylinder < bq->b_cylinder) {
while (bq->b_actf) {
/*
* Check for an ``inversion'' in the normally ascending
* cylinder numbers, indicating the start of the second
* request list.
*/
if (bq->b_actf->b_cylinder < bq->b_cylinder) {
/*
* Search the second request list for the first
* request at a larger cylinder number. We go
* before that; if there is no such request, we
* go at end.
*/
do {
if (bp->b_cylinder <
bq->b_actf->b_cylinder)
goto insert;
if (bp->b_cylinder ==
bq->b_actf->b_cylinder &&
bp->b_blkno < bq->b_actf->b_blkno)
goto insert;
bq = bq->b_actf;
} while (bq->b_actf);
goto insert; /* after last */
}
bq = bq->b_actf;
}
/*
* No inversions... we will go after the last, and
* be the first request in the second request list.
*/
goto insert;
}
/*
* Request is at/after the current request...
* sort in the first request list.
*/
while (bq->b_actf) {
/*
* We want to go after the current request if there is an
* inversion after it (i.e. it is the end of the first
* request list), or if the next request is a larger cylinder
* than our request.
*/
if (bq->b_actf->b_cylinder < bq->b_cylinder ||
bp->b_cylinder < bq->b_actf->b_cylinder ||
(bp->b_cylinder == bq->b_actf->b_cylinder &&
bp->b_blkno < bq->b_actf->b_blkno))
goto insert;
bq = bq->b_actf;
}
/*
* Neither a second list nor a larger request... we go at the end of
* the first list, which is the same as the end of the whole schebang.
*/
insert: bp->b_actf = bq->b_actf;
bq->b_actf = bp;
}
/*
* 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 *
correct_readdisklabel(dev, strat, lp)
dev_t dev;
d_strategy_t *strat;
register struct disklabel *lp;
{
register struct buf *bp;
struct disklabel *dlp;
char *msg = NULL;
#if 0
/*
* This clobbers valid labels built by drivers. It should fail,
* except on ancient systems, because it sets lp->d_npartitions
* to 1 but the label is supposed to be read from the raw partition,
* which is 0 only on ancient systems. Apparently most drivers
* don't check lp->d_npartitions.
*/
if (lp->d_secperunit == 0)
lp->d_secperunit = 0x1fffffff;
lp->d_npartitions = 1;
if (lp->d_partitions[0].p_size == 0)
lp->d_partitions[0].p_size = 0x1fffffff;
lp->d_partitions[0].p_offset = 0;
#endif
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 = "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)
msg = "no disk label";
} else if (dlp->d_npartitions > MAXPARTITIONS ||
dkcksum(dlp) != 0)
msg = "disk label corrupted";
else {
*lp = *dlp;
msg = NULL;
break;
}
}
bp->b_flags = B_INVAL | B_AGE;
brelse(bp);
return (msg);
}
#ifdef PRE_DISKSLICE_COMPAT
/*
* 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.
* If Machine Specific Partitions (MSP) are not found, then it will proceed
* as if the BSD partition starts at 0
* The MBR on an IBM PC is an example of an MSP.
*/
char *
readdisklabel(dev, strat, lp, dp, bdp)
dev_t dev;
void (*strat)();
register struct disklabel *lp;
struct dos_partition *dp;
struct dkbad *bdp;
{
register struct buf *bp;
struct disklabel *dlp;
char *msgMSP = NULL;
char *msg = NULL;
int i;
int cyl = 0;
/*
* Set up the disklabel as in case there is no MSP.
* We set the BSD part, but don't need to set the
* RAW part, because readMSPtolabel() will reset that
* itself. On return however, if there was no MSP,
* then we will be looking into OUR part to find the label
* and we will want that to start at 0, and have at least SOME length.
*/
if (lp->d_secperunit == 0)
lp->d_secperunit = 0x1fffffff;
lp->d_npartitions = OURPART + 1;
if (lp->d_partitions[OURPART].p_size == 0)
lp->d_partitions[OURPART].p_size = 0x100; /*enough for a label*/
lp->d_partitions[OURPART].p_offset = 0;
/*
* Dig out the Dos MSP.. If we get it, all remaining transfers
* will be relative to the base of the BSD part.
*/
msgMSP = readMSPtolabel(dev, strat, lp, dp, &cyl );
/*
* next, dig out disk label, relative to either the base of the
* BSD part, or block 0, depending on if an MSP was found.
*/
bp = geteblk((int)lp->d_secsize);
bp->b_blkno = LABELSECTOR;
bp->b_dev = makedev(major(dev), dkminor(dkunit(dev), OURPART));
bp->b_bcount = lp->d_secsize;
bp->b_flags = B_BUSY | B_READ;
bp->b_cylinder = cyl;
(*strat)(bp);
if (biowait(bp))
msg = "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)
msg = "no disk label";
} else if (dlp->d_npartitions > MAXPARTITIONS ||
dkcksum(dlp) != 0)
msg = "disk label corrupted";
else {
*lp = *dlp;
msg = NULL;
break;
}
}
if (msg && msgMSP) {
msg = msgMSP;
goto done;
}
/*
* Since we had one of the two labels, either one made up from the
* MSP, one found in the FreeBSD-MSP-partitions sector 2, or even
* one in sector 2 absolute on the disk, there is not really an error.
*/
msg = NULL;
/* obtain bad sector table if requested and present */
if (bdp && (lp->d_flags & D_BADSECT)) {
struct dkbad *db;
printf("d_secsize: %ld\n", lp->d_secsize);
i = 0;
do {
/* read a bad sector table */
bp->b_flags = B_BUSY | 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_un.b_addr);
#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:
bp->b_flags = B_INVAL | B_AGE;
brelse(bp);
return (msg);
}
#endif /* PRE_DISKSLICE_COMPAT */
/*
* Check new disk label for sensibility before setting it.
*/
int
setdisklabel(olp, nlp, openmask)
register struct disklabel *olp, *nlp;
u_long openmask;
{
register i;
register struct partition *opp, *npp;
/*
* Check it is actually a disklabel we are looking at.
*/
if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC ||
dkcksum(nlp) != 0)
return (EINVAL);
/*
* For each partition that we think is open,
*/
while ((i = ffs((long)openmask)) != 0) {
i--;
/*
* Check it is not changing....
*/
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 we are using it then we had better stay the same type)
* This is possibly dubious, as someone else noted (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.
*/
int
correct_writedisklabel(dev, strat, lp)
dev_t dev;
d_strategy_t *strat;
register struct disklabel *lp;
{
struct buf *bp;
struct disklabel *dlp;
int labelpart;
int error = 0;
labelpart = dkpart(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 = dkmodpart(dev, labelpart);
bp->b_blkno = LABELSECTOR;
bp->b_bcount = lp->d_secsize;
bp->b_flags = B_READ;
(*strat)(bp);
error = biowait(bp);
if (error)
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;
}
}
error = ESRCH;
done:
brelse(bp);
return (error);
}
#ifdef PRE_DISKSLICE_COMPAT
/*
* Write disk label back to device after modification.
* For FreeBSD 2.0(x86) this routine will refuse to install a label if
* there is no DOS MSP. (this can be changed)
*
* Assumptions for THIS VERSION:
* The given disklabel pointer is actually that which is controlling this
* Device, so that by fiddling it, readMSPtolabel() can ensure that
* it can read from the MSP if it exists,
* This assumption will cease as soon as ther is a better way of ensuring
* that a read is done to the whole raw device.
* MSP defines a BSD part, label is in block 1 (2nd block) of this
*/
int
writedisklabel(dev, strat, lp)
dev_t dev;
void (*strat)();
register struct disklabel *lp;
{
struct buf *bp = NULL;
struct disklabel *dlp;
int error = 0;
struct disklabel label;
char *msg;
int BSDstart,BSDlen;
int cyl; /* dummy arg for readMSPtolabel() */
/*
* Save the label (better be the real one)
* because we are going to play funny games with the disklabel
* controlling this device..
*/
bcopy(lp,&label,sizeof(label));
/*
* Unlike the read, we will trust the parameters given to us
* about the disk, in the new disklabel but will simply
* force OURPART to start at block 0 as a default in case there is NO
* MSP.
* readMSPtolabel() will reset it to start at the start of the BSD
* part if it exists
* At this time this is an error contition but I've left support for it
*/
lp->d_npartitions = OURPART + 1;
if (lp->d_partitions[OURPART].p_size == 0)
lp->d_partitions[OURPART].p_size = 0x1fffffff;
lp->d_partitions[OURPART].p_offset = 0;
msg = readMSPtolabel(dev, strat, lp, 0, &cyl );
/*
* If we want to be able to install without an Machine Specific
* Partitioning , then
* the failure of readMSPtolabel() should be made non fatal.
*/
if(msg) {
printf("writedisklabel:%s\n",msg);
error = ENXIO;
goto done;
}
/*
* If we had MSP (no message) but there
* was no BSD part in it
* then balk.. they should use fdisk to make one first or smash it..
* This may just be me being paranoid, but it's my choice for now..
* note we test for !msg, because the test above might be changed
* as a valid option..
*/
if((!msg) && (!(lp->d_subtype & DSTYPE_INDOSPART))) {
printf("writedisklabel: MSP with no BSD part\n");
}
/*
* get all the other bits back from the good new disklabel
* (the user wouldn't try confuse us would he?)
* With the exception of the OURPART which now points to the
* BSD partition.
*/
BSDstart = lp->d_partitions[OURPART].p_offset;
BSDlen = lp->d_partitions[OURPART].p_size;
bcopy(&label,lp,sizeof(label));
lp->d_partitions[OURPART].p_offset = BSDstart;
lp->d_partitions[OURPART].p_size = BSDlen;
bp = geteblk((int)lp->d_secsize);
bp->b_dev = makedev(major(dev), dkminor(dkunit(dev), OURPART));
bp->b_blkno = LABELSECTOR;
bp->b_bcount = lp->d_secsize;
#ifdef STUPID
/*
* We read the label first to see if it's there,
* in which case we will put ours at the same offset into the block..
* (I think this is stupid [Julian])
* Note that you can't write a label out over a corrupted label!
* (also stupid.. how do you write the first one? by raw writes?)
*/
bp->b_flags = B_READ;
(*strat)(bp);
error = biowait(bp);
if (error)
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) {
bcopy(&label,dlp,sizeof(label));
bp->b_flags = B_WRITE;
(*strat)(bp);
error = biowait(bp);
goto done;
}
}
error = ESRCH;
#else /* Stupid */
dlp = (struct disklabel *)bp->b_data;
bcopy(&label,dlp,sizeof(label));
bp->b_flags = B_WRITE;
(*strat)(bp);
error = biowait(bp);
#endif /* Stupid */
done:
bcopy(&label,lp,sizeof(label)); /* start using the new label again */
if(bp)
brelse(bp);
return (error);
}
#endif /* PRE_DISKSLICE_COMPAT */
/*
* Compute checksum for disk label.
*/
u_int
dkcksum(lp)
register struct disklabel *lp;
{
register u_short *start, *end;
register u_short sum = 0;
start = (u_short *)lp;
end = (u_short *)&lp->d_partitions[lp->d_npartitions];
while (start < end)
sum ^= *start++;
return (sum);
}
/*
* Disk error is the preface to plaintive error messages
* about failing disk transfers. It prints messages of the form
hp0g: hard error reading fsbn 12345 of 12344-12347 (hp0 bn %d cn %d tn %d sn %d)
* if the offset of the error in the transfer and a disk label
* are both available. blkdone should be -1 if the position of the error
* is unknown; the disklabel pointer may be null from drivers that have not
* been converted to use them. The message is printed with printf
* if pri is LOG_PRINTF, otherwise it uses log at the specified priority.
* The message should be completed (with at least a newline) with printf
* or addlog, respectively. There is no trailing space.
*/
void
diskerr(bp, dname, what, pri, blkdone, lp)
register struct buf *bp;
char *dname, *what;
int pri, blkdone;
register struct disklabel *lp;
{
int unit = dkunit(bp->b_dev);
int slice = dkslice(bp->b_dev);
int part = dkpart(bp->b_dev);
register void (*pr) __P((const char *, ...));
char partname[2];
char *sname;
int sn;
if (pri != LOG_PRINTF) {
log(pri, "");
pr = addlog;
} else
pr = printf;
sname = dsname("", unit, slice, part, partname);
(*pr)("%s%s: %s %sing fsbn ", sname, partname, what,
bp->b_flags & B_READ ? "read" : "writ");
sn = bp->b_blkno;
if (bp->b_bcount <= DEV_BSIZE)
(*pr)("%d", sn);
else {
if (blkdone >= 0) {
sn += blkdone;
(*pr)("%d of ", sn);
}
(*pr)("%d-%d", bp->b_blkno,
bp->b_blkno + (bp->b_bcount - 1) / DEV_BSIZE);
}
if (lp && (blkdone >= 0 || bp->b_bcount <= lp->d_secsize)) {
#ifdef tahoe
sn *= DEV_BSIZE / lp->d_secsize; /* XXX */
#endif
sn += lp->d_partitions[part].p_offset;
/*
* XXX should add slice offset and not print the slice,
* but we don't know the slice pointer.
* XXX should print bp->b_pblkno so that this will work
* independent of slices, labels and bad sector remapping,
* but some drivers don't set bp->b_pblkno.
*/
(*pr)(" (%s bn %d; cn %d", sname, sn, sn / lp->d_secpercyl);
sn %= lp->d_secpercyl;
(*pr)(" tn %d sn %d)", sn / lp->d_nsectors, sn % lp->d_nsectors);
}
}
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