[unix-history] / 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);
	}
}
Commit	Line	Data
da7c5cc6	1	/*
1ad7f5c8	2	* Copyright (c) 1982, 1986, 1988 Regents of the University of California.
7188ac27	3	* All rights reserved.
da7c5cc6	4	*
af359dea C	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
7188ac27	20	*
af359dea C	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*
	33	* @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91
da7c5cc6	34	*/
200a8f27	35
97934dfa MK	36	#include "param.h"
	37	#include "systm.h"
	38	#include "buf.h"
	39	#include "disklabel.h"
1ad7f5c8	40	#include "syslog.h"
9573c71c	41
200a8f27	42	/*
0d67fde4 BJ	43	* Seek sort for disks. We depend on the driver
	44	* which calls us using b_resid as the current cylinder number.
	45	*
	46	* The argument dp structure holds a b_actf activity chain pointer
	47	* on which we keep two queues, sorted in ascending cylinder order.
	48	* The first queue holds those requests which are positioned after
	49	* the current cylinder (in the first request); the second holds
	50	* requests which came in after their cylinder number was passed.
	51	* Thus we implement a one way scan, retracting after reaching the
	52	* end of the drive to the first request on the second queue,
	53	* at which time it becomes the first queue.
	54	*
	55	* A one-way scan is natural because of the way UNIX read-ahead
	56	* blocks are allocated.
200a8f27 BJ	57	*/
200a8f27 BJ	58
200a8f27 BJ	59	#define b_cylin b_resid
	60
	61	disksort(dp, bp)
0d67fde4	62	register struct buf dp, bp;
200a8f27 BJ	63	{
200a8f27 BJ	64	register struct buf *ap;
200a8f27	65
0d67fde4 BJ	66	/*
	67	* If nothing on the activity queue, then
	68	* we become the only thing.
	69	*/
200a8f27 BJ	70	ap = dp->b_actf;
	71	if(ap == NULL) {
	72	dp->b_actf = bp;
	73	dp->b_actl = bp;
	74	bp->av_forw = NULL;
	75	return;
	76	}
0d67fde4 BJ	77	/*
	78	* If we lie after the first (currently active)
	79	* request, then we must locate the second request list
	80	* and add ourselves to it.
	81	*/
	82	if (bp->b_cylin < ap->b_cylin) {
	83	while (ap->av_forw) {
	84	/*
	85	* Check for an ``inversion'' in the
	86	* normally ascending cylinder numbers,
	87	* indicating the start of the second request list.
	88	*/
	89	if (ap->av_forw->b_cylin < ap->b_cylin) {
	90	/*
	91	* Search the second request list
	92	* for the first request at a larger
	93	* cylinder number. We go before that;
	94	* if there is no such request, we go at end.
	95	*/
	96	do {
	97	if (bp->b_cylin < ap->av_forw->b_cylin)
	98	goto insert;
667e5665 MK	99	if (bp->b_cylin == ap->av_forw->b_cylin &&
	100	bp->b_blkno < ap->av_forw->b_blkno)
	101	goto insert;
0d67fde4 BJ	102	ap = ap->av_forw;
	103	} while (ap->av_forw);
	104	goto insert; /* after last */
	105	}
	106	ap = ap->av_forw;
200a8f27	107	}
0d67fde4 BJ	108	/*
	109	* No inversions... we will go after the last, and
	110	* be the first request in the second request list.
	111	*/
	112	goto insert;
200a8f27	113	}
0d67fde4 BJ	114	/*
	115	* Request is at/after the current request...
	116	* sort in the first request list.
	117	*/
	118	while (ap->av_forw) {
	119	/*
	120	* We want to go after the current request
	121	* if there is an inversion after it (i.e. it is
	122	* the end of the first request list), or if
	123	* the next request is a larger cylinder than our request.
	124	*/
	125	if (ap->av_forw->b_cylin < ap->b_cylin \|\|
667e5665 MK	126	bp->b_cylin < ap->av_forw->b_cylin \|\|
	127	(bp->b_cylin == ap->av_forw->b_cylin &&
	128	bp->b_blkno < ap->av_forw->b_blkno))
0d67fde4 BJ	129	goto insert;
	130	ap = ap->av_forw;
	131	}
	132	/*
	133	* Neither a second list nor a larger
	134	* request... we go at the end of the first list,
	135	* which is the same as the end of the whole schebang.
	136	*/
	137	insert:
	138	bp->av_forw = ap->av_forw;
	139	ap->av_forw = bp;
	140	if (ap == dp->b_actl)
200a8f27 BJ	141	dp->b_actl = bp;
200a8f27 BJ	142	}
97934dfa	143
9573c71c MK	144	/*
	145	* Attempt to read a disk label from a device
	146	* using the indicated stategy routine.
	147	* The label must be partly set up before this:
	148	* secpercyl and anything required in the strategy routine
	149	* (e.g., sector size) must be filled in before calling us.
	150	* Returns null on success and an error string on failure.
	151	*/
	152	char *
	153	readdisklabel(dev, strat, lp)
	154	dev_t dev;
	155	int (*strat)();
	156	register struct disklabel *lp;
	157	{
	158	register struct buf *bp;
	159	struct disklabel *dlp;
	160	char *msg = NULL;
	161
	162	if (lp->d_secperunit == 0)
	163	lp->d_secperunit = 0x1fffffff;
	164	lp->d_npartitions = 1;
	165	if (lp->d_partitions[0].p_size == 0)
	166	lp->d_partitions[0].p_size = 0x1fffffff;
	167	lp->d_partitions[0].p_offset = 0;
	168
d3633d66	169	bp = geteblk((int)lp->d_secsize);
9573c71c MK	170	bp->b_dev = dev;
9573c71c MK	171	bp->b_blkno = LABELSECTOR;
cd6cd535	172	bp->b_bcount = lp->d_secsize;
9573c71c MK	173	bp->b_flags = B_BUSY \| B_READ;
	174	bp->b_cylin = LABELSECTOR / lp->d_secpercyl;
	175	(*strat)(bp);
7188ac27	176	if (biowait(bp)) {
9573c71c	177	msg = "I/O error";
cd6cd535 MK	178	} else for (dlp = (struct disklabel *)bp->b_un.b_addr;
	179	dlp <= (struct disklabel )(bp->b_un.b_addr+DEV_BSIZE-sizeof(dlp));
	180	dlp = (struct disklabel )((char )dlp + sizeof(long))) {
	181	if (dlp->d_magic != DISKMAGIC \|\| dlp->d_magic2 != DISKMAGIC) {
	182	if (msg == NULL)
	183	msg = "no disk label";
0328954d KM	184	} else if (dlp->d_npartitions > MAXPARTITIONS \|\|
0328954d KM	185	dkcksum(dlp) != 0)
9573c71c	186	msg = "disk label corrupted";
cd6cd535	187	else {
9573c71c	188	lp = dlp;
cd6cd535 MK	189	msg = NULL;
	190	break;
	191	}
9573c71c MK	192	}
	193	bp->b_flags = B_INVAL \| B_AGE;
	194	brelse(bp);
	195	return (msg);
	196	}
	197
667e5665 MK	198	/*
	199	* Check new disk label for sensibility
	200	* before setting it.
	201	*/
	202	setdisklabel(olp, nlp, openmask)
	203	register struct disklabel olp, nlp;
	204	u_long openmask;
	205	{
	206	register i;
	207	register struct partition opp, npp;
	208
	209	if (nlp->d_magic != DISKMAGIC \|\| nlp->d_magic2 != DISKMAGIC \|\|
	210	dkcksum(nlp) != 0)
	211	return (EINVAL);
5adcb337	212	while ((i = ffs((long)openmask)) != 0) {
667e5665 MK	213	i--;
	214	openmask &= ~(1 << i);
	215	if (nlp->d_npartitions <= i)
	216	return (EBUSY);
	217	opp = &olp->d_partitions[i];
	218	npp = &nlp->d_partitions[i];
	219	if (npp->p_offset != opp->p_offset \|\| npp->p_size < opp->p_size)
	220	return (EBUSY);
	221	/*
	222	* Copy internally-set partition information
	223	* if new label doesn't include it. XXX
	224	*/
	225	if (npp->p_fstype == FS_UNUSED && opp->p_fstype != FS_UNUSED) {
	226	npp->p_fstype = opp->p_fstype;
	227	npp->p_fsize = opp->p_fsize;
	228	npp->p_frag = opp->p_frag;
	229	npp->p_cpg = opp->p_cpg;
	230	}
	231	}
d3633d66 MK	232	nlp->d_checksum = 0;
d3633d66 MK	233	nlp->d_checksum = dkcksum(nlp);
667e5665 MK	234	olp = nlp;
	235	return (0);
	236	}
	237
	238	/* encoding of disk minor numbers, should be elsewhere... */
	239	#define dkunit(dev) (minor(dev) >> 3)
	240	#define dkpart(dev) (minor(dev) & 07)
	241	#define dkminor(unit, part) (((unit) << 3) \| (part))
	242
	243	/*
	244	* Write disk label back to device after modification.
	245	*/
	246	writedisklabel(dev, strat, lp)
	247	dev_t dev;
	248	int (*strat)();
	249	register struct disklabel *lp;
	250	{
	251	struct buf *bp;
	252	struct disklabel *dlp;
	253	int labelpart;
	254	int error = 0;
	255
	256	labelpart = dkpart(dev);
	257	if (lp->d_partitions[labelpart].p_offset != 0) {
	258	if (lp->d_partitions[0].p_offset != 0)
	259	return (EXDEV); /* not quite right */
	260	labelpart = 0;
	261	}
d3633d66	262	bp = geteblk((int)lp->d_secsize);
667e5665 MK	263	bp->b_dev = makedev(major(dev), dkminor(dkunit(dev), labelpart));
	264	bp->b_blkno = LABELSECTOR;
	265	bp->b_bcount = lp->d_secsize;
	266	bp->b_flags = B_READ;
	267	(*strat)(bp);
7188ac27	268	if (error = biowait(bp))
d3633d66	269	goto done;
d3633d66 MK	270	for (dlp = (struct disklabel *)bp->b_un.b_addr;
	271	dlp <= (struct disklabel *)
	272	(bp->b_un.b_addr + lp->d_secsize - sizeof(*dlp));
	273	dlp = (struct disklabel )((char )dlp + sizeof(long))) {
	274	if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC &&
	275	dkcksum(dlp) == 0) {
	276	dlp = lp;
	277	bp->b_flags = B_WRITE;
	278	(*strat)(bp);
7188ac27	279	error = biowait(bp);
d3633d66 MK	280	goto done;
d3633d66 MK	281	}
667e5665	282	}
d3633d66 MK	283	error = ESRCH;
d3633d66 MK	284	done:
667e5665 MK	285	brelse(bp);
	286	return (error);
	287	}
	288
97934dfa MK	289	/*
	290	* Compute checksum for disk label.
	291	*/
	292	dkcksum(lp)
	293	register struct disklabel *lp;
	294	{
	295	register u_short start, end;
	296	register u_short sum = 0;
	297
	298	start = (u_short *)lp;
	299	end = (u_short *)&lp->d_partitions[lp->d_npartitions];
	300	while (start < end)
	301	sum ^= *start++;
	302	return (sum);
	303	}
1ad7f5c8 MK	304
	305	/*
	306	* Disk error is the preface to plaintive error messages
	307	* about failing disk transfers. It prints messages of the form
05de9101 MK	308
	309	hp0g: hard error reading fsbn 12345 of 12344-12347 (hp0 bn %d cn %d tn %d sn %d)
	310
1ad7f5c8 MK	311	* if the offset of the error in the transfer and a disk label
	312	* are both available. blkdone should be -1 if the position of the error
	313	* is unknown; the disklabel pointer may be null from drivers that have not
	314	* been converted to use them. The message is printed with printf
	315	* if pri is LOG_PRINTF, otherwise it uses log at the specified priority.
	316	* The message should be completed (with at least a newline) with printf
	317	* or addlog, respectively. There is no trailing space.
	318	*/
	319	diskerr(bp, dname, what, pri, blkdone, lp)
	320	register struct buf *bp;
	321	char dname, what;
	322	int pri, blkdone;
	323	register struct disklabel *lp;
	324	{
	325	int unit = dkunit(bp->b_dev), part = dkpart(bp->b_dev);
af359dea	326	register void (pr) __P((const char , ...));
1ad7f5c8	327	char partname = 'a' + part;
af359dea	328	int sn;
1ad7f5c8 MK	329
	330	if (pri != LOG_PRINTF) {
	331	log(pri, "");
	332	pr = addlog;
	333	} else
	334	pr = printf;
	335	(*pr)("%s%d%c: %s %sing fsbn ", dname, unit, partname, what,
	336	bp->b_flags & B_READ ? "read" : "writ");
	337	sn = bp->b_blkno;
	338	if (bp->b_bcount <= DEV_BSIZE)
	339	(*pr)("%d", sn);
	340	else {
	341	if (blkdone >= 0) {
	342	sn += blkdone;
	343	(*pr)("%d of ", sn);
	344	}
	345	(*pr)("%d-%d", bp->b_blkno,
	346	bp->b_blkno + (bp->b_bcount - 1) / DEV_BSIZE);
	347	}
f2a9617b MK	348	if (lp && (blkdone >= 0 \|\| bp->b_bcount <= lp->d_secsize)) {
	349	#ifdef tahoe
	350	sn = DEV_BSIZE / lp->d_secsize; / XXX */
	351	#endif
1ad7f5c8	352	sn += lp->d_partitions[part].p_offset;
05de9101 MK	353	(*pr)(" (%s%d bn %d; cn %d", dname, unit, sn,
	354	sn / lp->d_secpercyl);
	355	sn %= lp->d_secpercyl;
9f79ca31	356	(*pr)(" tn %d sn %d)", sn / lp->d_nsectors, sn % lp->d_nsectors);
1ad7f5c8 MK	357	}
1ad7f5c8 MK	358	}