disksubr.c revision 1.13 
1/*	$NetBSD: disksubr.c,v 1.13 1996/10/13 03:39:49 christos Exp $	*/
2
3/*
4 * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by the University of
18 *	California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 *	@(#)ufs_disksubr.c	7.16 (Berkeley) 5/4/91
36 */
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/buf.h>
41#include <sys/device.h>
42#include <sys/disk.h>
43#include <sys/disklabel.h>
44#include <sys/syslog.h>
45
46#define	b_cylin	b_resid
47
48#ifdef COMPAT_ULTRIX
49#include "../../stand/dec_boot.h"
50
51extern char *
52compat_label __P((dev_t dev, void (*strat) __P((struct buf *bp)),
53		  struct disklabel *lp, struct cpu_disklabel *osdep));
54
55#endif
56
57char*	readdisklabel __P((dev_t dev, void (*strat) __P((struct buf *bp)),
58		       register struct disklabel *lp,
59		       struct cpu_disklabel *osdep));
60
61/*
62 * Attempt to read a disk label from a device
63 * using the indicated stategy routine.
64 * The label must be partly set up before this:
65 * secpercyl and anything required in the strategy routine
66 * (e.g., sector size) must be filled in before calling us.
67 * Returns null on success and an error string on failure.
68 */
69char *
70readdisklabel(dev, strat, lp, osdep)
71	dev_t dev;
72	void (*strat) __P((struct buf *bp));
73	register struct disklabel *lp;
74	struct cpu_disklabel *osdep;
75{
76	register struct buf *bp;
77	struct disklabel *dlp;
78	char *msg = NULL;
79
80	if (lp->d_secperunit == 0)
81		lp->d_secperunit = 0x1fffffff;
82	lp->d_npartitions = 1;
83	if (lp->d_partitions[0].p_size == 0)
84		lp->d_partitions[0].p_size = 0x1fffffff;
85	lp->d_partitions[0].p_offset = 0;
86
87	bp = geteblk((int)lp->d_secsize);
88	bp->b_dev = dev;
89	bp->b_blkno = LABELSECTOR;
90	bp->b_bcount = lp->d_secsize;
91	bp->b_flags = B_BUSY | B_READ;
92	bp->b_cylin = LABELSECTOR / lp->d_secpercyl;
93	(*strat)(bp);
94	if (biowait(bp)) {
95		msg = "I/O error";
96	} else for (dlp = (struct disklabel *)bp->b_un.b_addr;
97	    dlp <= (struct disklabel *)(bp->b_un.b_addr+DEV_BSIZE-sizeof(*dlp));
98	    dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
99		if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) {
100			if (msg == NULL)
101				msg = "no disk label";
102		} else if (dlp->d_npartitions > MAXPARTITIONS ||
103			   dkcksum(dlp) != 0)
104			msg = "disk label corrupted";
105		else {
106			*lp = *dlp;
107			msg = NULL;
108			break;
109		}
110	}
111	bp->b_flags = B_INVAL | B_AGE;
112	brelse(bp);
113	return (msg);
114}
115
116#ifdef COMPAT_ULTRIX
117/*
118 * Given a buffer bp, try and interpret it as an Ultrix disk label,
119 * putting the partition info into a native NetBSD label
120 */
121char *
122compat_label(dev, strat, lp, osdep)
123	dev_t dev;
124	void (*strat) __P((struct buf *bp));
125	register struct disklabel *lp;
126	struct cpu_disklabel *osdep;
127{
128	Dec_DiskLabel *dlp;
129	struct buf *bp = NULL;
130	char *msg = NULL;
131
132	bp = geteblk((int)lp->d_secsize);
133	bp->b_dev = dev;
134	bp->b_blkno = DEC_LABEL_SECTOR;
135	bp->b_bcount = lp->d_secsize;
136	bp->b_flags = B_BUSY | B_READ;
137	bp->b_cylin = DEC_LABEL_SECTOR / lp->d_secpercyl;
138	(*strat)(bp);
139
140	if (biowait(bp)) {
141                msg = "I/O error";
142		goto done;
143	}
144
145	for (dlp = (Dec_DiskLabel *)bp->b_un.b_addr;
146	     dlp <= (Dec_DiskLabel *)(bp->b_un.b_addr+DEV_BSIZE-sizeof(*dlp));
147	     dlp = (Dec_DiskLabel *)((char *)dlp + sizeof(long))) {
148
149		int part;
150
151		if (dlp->magic != DEC_LABEL_MAGIC) {
152			printf("label: %x\n",dlp->magic);
153			msg = ((msg != NULL) ? msg: "no disk label");
154			goto done;
155		}
156
157#ifdef DIAGNOSTIC
158/*XXX*/		printf("Interpreting Ultrix label\n");
159#endif
160
161		lp->d_magic = DEC_LABEL_MAGIC;
162		lp->d_npartitions = 0;
163		for (part = 0;
164		     part <((MAXPARTITIONS<DEC_NUM_DISK_PARTS) ?
165			    MAXPARTITIONS : DEC_NUM_DISK_PARTS);
166		     part++) {
167			lp->d_partitions[part].p_size = dlp->map[part].numBlocks;
168			lp->d_partitions[part].p_offset = dlp->map[part].startBlock;
169			lp->d_partitions[part].p_fsize = 1024;
170			lp->d_partitions[part].p_fstype =
171			  (part==1) ? FS_SWAP : FS_BSDFFS;
172			lp->d_npartitions += 1;
173
174#ifdef DIAGNOSTIC
175			printf(" Ultrix label rz%d%c: start %d len %d\n",
176			       DISKUNIT(dev), "abcdefgh"[part],
177			       lp->d_partitions[part].p_offset,
178			       lp->d_partitions[part].p_size);
179#endif
180		}
181		break;
182	}
183
184done:
185	bp->b_flags = B_INVAL | B_AGE;
186	brelse(bp);
187	return (msg);
188}
189#endif /* COMPAT_ULTRIX */
190
191
192/*
193 * Check new disk label for sensibility
194 * before setting it.
195 */
196int
197setdisklabel(olp, nlp, openmask, osdep)
198	register struct disklabel *olp, *nlp;
199	u_long openmask;
200	struct cpu_disklabel *osdep;
201{
202	register i;
203	register struct partition *opp, *npp;
204
205	if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC ||
206	    dkcksum(nlp) != 0)
207		return (EINVAL);
208	while ((i = ffs((long)openmask)) != 0) {
209		i--;
210		openmask &= ~(1 << i);
211		if (nlp->d_npartitions <= i)
212			return (EBUSY);
213		opp = &olp->d_partitions[i];
214		npp = &nlp->d_partitions[i];
215		if (npp->p_offset != opp->p_offset || npp->p_size < opp->p_size)
216			return (EBUSY);
217		/*
218		 * Copy internally-set partition information
219		 * if new label doesn't include it.		XXX
220		 */
221		if (npp->p_fstype == FS_UNUSED && opp->p_fstype != FS_UNUSED) {
222			npp->p_fstype = opp->p_fstype;
223			npp->p_fsize = opp->p_fsize;
224			npp->p_frag = opp->p_frag;
225			npp->p_cpg = opp->p_cpg;
226		}
227	}
228 	nlp->d_checksum = 0;
229 	nlp->d_checksum = dkcksum(nlp);
230	*olp = *nlp;
231	return (0);
232}
233
234/* encoding of disk minor numbers, should be elsewhere... */
235#define dkunit(dev)		(minor(dev) >> 3)
236#define dkpart(dev)		(minor(dev) & 07)
237#define dkminor(unit, part)	(((unit) << 3) | (part))
238
239/*
240 * Write disk label back to device after modification.
241 */
242int
243writedisklabel(dev, strat, lp, osdep)
244	dev_t dev;
245	void (*strat) __P((struct buf *bp));
246	register struct disklabel *lp;
247	struct cpu_disklabel *osdep;
248{
249	struct buf *bp;
250	struct disklabel *dlp;
251	int labelpart;
252	int error = 0;
253
254	labelpart = dkpart(dev);
255	if (lp->d_partitions[labelpart].p_offset != 0) {
256		if (lp->d_partitions[0].p_offset != 0)
257			return (EXDEV);			/* not quite right */
258		labelpart = 0;
259	}
260	bp = geteblk((int)lp->d_secsize);
261	bp->b_dev = makedev(major(dev), dkminor(dkunit(dev), labelpart));
262	bp->b_blkno = LABELSECTOR;
263	bp->b_bcount = lp->d_secsize;
264	bp->b_flags = B_READ;
265	(*strat)(bp);
266	if ((error = biowait(bp)) != 0)
267		goto done;
268	for (dlp = (struct disklabel *)bp->b_un.b_addr;
269	    dlp <= (struct disklabel *)
270	      (bp->b_un.b_addr + lp->d_secsize - sizeof(*dlp));
271	    dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
272		if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC &&
273		    dkcksum(dlp) == 0) {
274			*dlp = *lp;
275			bp->b_flags = B_WRITE;
276			(*strat)(bp);
277			error = biowait(bp);
278			goto done;
279		}
280	}
281	error = ESRCH;
282done:
283	brelse(bp);
284	return (error);
285}
286
287
288/*
289 * was this the boot device ?
290 */
291void
292dk_establish(dk, dev)
293	struct disk *dk;
294	struct device *dev;
295{
296	/* see also arch/alpha/alpha/disksubr.c */
297	printf("Warning: boot path unknown\n");
298	return;
299}
300
301/*
302 * UNTESTED !!
303 *
304 * Determine the size of the transfer, and make sure it is
305 * within the boundaries of the partition. Adjust transfer
306 * if needed, and signal errors or early completion.
307 */
308int
309bounds_check_with_label(bp, lp, wlabel)
310	struct buf *bp;
311	struct disklabel *lp;
312	int wlabel;
313{
314
315	struct partition *p = lp->d_partitions + dkpart(bp->b_dev);
316	int labelsect = lp->d_partitions[0].p_offset;
317	int maxsz = p->p_size;
318	int sz = (bp->b_bcount + DEV_BSIZE - 1) >> DEV_BSHIFT;
319
320	/* overwriting disk label ? */
321	/* XXX should also protect bootstrap in first 8K */
322	if (bp->b_blkno + p->p_offset <= LABELSECTOR + labelsect &&
323	    (bp->b_flags & B_READ) == 0 && wlabel == 0) {
324		bp->b_error = EROFS;
325		goto bad;
326	}
327
328	/* beyond partition? */
329	if (bp->b_blkno < 0 || bp->b_blkno + sz > maxsz) {
330		/* if exactly at end of disk, return an EOF */
331		if (bp->b_blkno == maxsz) {
332			bp->b_resid = bp->b_bcount;
333			return(0);
334		}
335		/* or truncate if part of it fits */
336		sz = maxsz - bp->b_blkno;
337		if (sz <= 0) {
338			bp->b_error = EINVAL;
339			goto bad;
340		}
341		bp->b_bcount = sz << DEV_BSHIFT;
342	}
343
344	/* calculate cylinder for disksort to order transfers with */
345	bp->b_resid = (bp->b_blkno + p->p_offset) / lp->d_secpercyl;
346	return(1);
347bad:
348	bp->b_flags |= B_ERROR;
349	return(-1);
350}
351