Net2/usr/src/sys/ufs/ufs_disksubr.c
/*
* 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. 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 7.16 (Berkeley) 5/4/91
*/
#include "param.h"
#include "systm.h"
#include "buf.h"
#include "disklabel.h"
#include "syslog.h"
/*
* Seek sort for disks. We depend on the driver
* which calls us using b_resid as the current cylinder number.
*
* The argument dp 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.
*/
#define b_cylin b_resid
disksort(dp, bp)
register struct buf *dp, *bp;
{
register struct buf *ap;
/*
* If nothing on the activity queue, then
* we become the only thing.
*/
ap = dp->b_actf;
if(ap == NULL) {
dp->b_actf = bp;
dp->b_actl = bp;
bp->av_forw = NULL;
return;
}
/*
* If we lie after the first (currently active)
* request, then we must locate the second request list
* and add ourselves to it.
*/
if (bp->b_cylin < ap->b_cylin) {
while (ap->av_forw) {
/*
* Check for an ``inversion'' in the
* normally ascending cylinder numbers,
* indicating the start of the second request list.
*/
if (ap->av_forw->b_cylin < ap->b_cylin) {
/*
* 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_cylin < ap->av_forw->b_cylin)
goto insert;
if (bp->b_cylin == ap->av_forw->b_cylin &&
bp->b_blkno < ap->av_forw->b_blkno)
goto insert;
ap = ap->av_forw;
} while (ap->av_forw);
goto insert; /* after last */
}
ap = ap->av_forw;
}
/*
* 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 (ap->av_forw) {
/*
* 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 (ap->av_forw->b_cylin < ap->b_cylin ||
bp->b_cylin < ap->av_forw->b_cylin ||
(bp->b_cylin == ap->av_forw->b_cylin &&
bp->b_blkno < ap->av_forw->b_blkno))
goto insert;
ap = ap->av_forw;
}
/*
* 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->av_forw = ap->av_forw;
ap->av_forw = bp;
if (ap == dp->b_actl)
dp->b_actl = 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 *
readdisklabel(dev, strat, lp)
dev_t dev;
int (*strat)();
register struct disklabel *lp;
{
register struct buf *bp;
struct disklabel *dlp;
char *msg = NULL;
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;
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_cylin = LABELSECTOR / lp->d_secpercyl;
(*strat)(bp);
if (biowait(bp)) {
msg = "I/O error";
} else for (dlp = (struct disklabel *)bp->b_un.b_addr;
dlp <= (struct disklabel *)(bp->b_un.b_addr+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);
}
/*
* Check new disk label for sensibility
* before setting it.
*/
setdisklabel(olp, nlp, openmask)
register struct disklabel *olp, *nlp;
u_long openmask;
{
register i;
register 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_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);
}
/* encoding of disk minor numbers, should be elsewhere... */
#define dkunit(dev) (minor(dev) >> 3)
#define dkpart(dev) (minor(dev) & 07)
#define dkminor(unit, part) (((unit) << 3) | (part))
/*
* Write disk label back to device after modification.
*/
writedisklabel(dev, strat, lp)
dev_t dev;
int (*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 = makedev(major(dev), dkminor(dkunit(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_un.b_addr;
dlp <= (struct disklabel *)
(bp->b_un.b_addr + 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);
}
/*
* Compute checksum for disk label.
*/
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.
*/
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), part = dkpart(bp->b_dev);
register void (*pr) __P((const char *, ...));
char partname = 'a' + part;
int sn;
if (pri != LOG_PRINTF) {
log(pri, "");
pr = addlog;
} else
pr = printf;
(*pr)("%s%d%c: %s %sing fsbn ", dname, unit, 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;
(*pr)(" (%s%d bn %d; cn %d", dname, unit, sn,
sn / lp->d_secpercyl);
sn %= lp->d_secpercyl;
(*pr)(" tn %d sn %d)", sn / lp->d_nsectors, sn % lp->d_nsectors);
}
}