disksubr.c revision 1.19 
1/*	$NetBSD: disksubr.c,v 1.19 1999/03/25 01:17:52 simonb 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 "opt_compat_ultrix.h"
39
40#include <sys/param.h>
41#include <sys/systm.h>
42#include <sys/buf.h>
43#include <sys/device.h>
44#include <sys/disk.h>
45#include <sys/disklabel.h>
46#include <sys/syslog.h>
47
48#define	b_cylin	b_resid
49
50#ifdef COMPAT_ULTRIX
51#include <machine/dec_boot.h>
52
53extern char *
54compat_label __P((dev_t dev, void (*strat) __P((struct buf *bp)),
55		  struct disklabel *lp, struct cpu_disklabel *osdep));
56
57#endif
58
59char*	readdisklabel __P((dev_t dev, void (*strat) __P((struct buf *bp)),
60		       register struct disklabel *lp,
61		       struct cpu_disklabel *osdep));
62
63/*
64 * Attempt to read a disk label from a device
65 * using the indicated stategy routine.
66 * The label must be partly set up before this:
67 * secpercyl and anything required in the strategy routine
68 * (e.g., sector size) must be filled in before calling us.
69 * Returns null on success and an error string on failure.
70 */
71char *
72readdisklabel(dev, strat, lp, osdep)
73	dev_t dev;
74	void (*strat) __P((struct buf *bp));
75	register struct disklabel *lp;
76	struct cpu_disklabel *osdep;
77{
78	register struct buf *bp;
79	struct disklabel *dlp;
80	char *msg = NULL;
81
82	if (lp->d_secperunit == 0)
83		lp->d_secperunit = 0x1fffffff;
84	lp->d_npartitions = 1;
85	if (lp->d_partitions[0].p_size == 0)
86		lp->d_partitions[0].p_size = 0x1fffffff;
87	lp->d_partitions[0].p_offset = 0;
88
89	bp = geteblk((int)lp->d_secsize);
90	bp->b_dev = dev;
91	bp->b_blkno = LABELSECTOR;
92	bp->b_bcount = lp->d_secsize;
93	bp->b_flags = B_BUSY | B_READ;
94	bp->b_cylin = LABELSECTOR / lp->d_secpercyl;
95	(*strat)(bp);
96	if (biowait(bp)) {
97		msg = "I/O error";
98	} else for (dlp = (struct disklabel *)bp->b_un.b_addr;
99	    dlp <= (struct disklabel *)(bp->b_un.b_addr+DEV_BSIZE-sizeof(*dlp));
100	    dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
101		if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) {
102			if (msg == NULL)
103				msg = "no disk label";
104		} else if (dlp->d_npartitions > MAXPARTITIONS ||
105			   dkcksum(dlp) != 0)
106			msg = "disk label corrupted";
107		else {
108			*lp = *dlp;
109			msg = NULL;
110			break;
111		}
112	}
113	bp->b_flags = B_INVAL | B_AGE;
114	brelse(bp);
115	return (msg);
116}
117
118#ifdef COMPAT_ULTRIX
119/*
120 * Given a buffer bp, try and interpret it as an Ultrix disk label,
121 * putting the partition info into a native NetBSD label
122 */
123char *
124compat_label(dev, strat, lp, osdep)
125	dev_t dev;
126	void (*strat) __P((struct buf *bp));
127	register struct disklabel *lp;
128	struct cpu_disklabel *osdep;
129{
130	Dec_DiskLabel *dlp;
131	struct buf *bp = NULL;
132	char *msg = NULL;
133
134	bp = geteblk((int)lp->d_secsize);
135	bp->b_dev = dev;
136	bp->b_blkno = DEC_LABEL_SECTOR;
137	bp->b_bcount = lp->d_secsize;
138	bp->b_flags = B_BUSY | B_READ;
139	bp->b_cylin = DEC_LABEL_SECTOR / lp->d_secpercyl;
140	(*strat)(bp);
141
142	if (biowait(bp)) {
143                msg = "I/O error";
144		goto done;
145	}
146
147	for (dlp = (Dec_DiskLabel *)bp->b_un.b_addr;
148	     dlp <= (Dec_DiskLabel *)(bp->b_un.b_addr+DEV_BSIZE-sizeof(*dlp));
149	     dlp = (Dec_DiskLabel *)((char *)dlp + sizeof(long))) {
150
151		int part;
152
153		if (dlp->magic != DEC_LABEL_MAGIC) {
154			printf("label: %x\n",dlp->magic);
155			msg = ((msg != NULL) ? msg: "no disk label");
156			goto done;
157		}
158
159#ifdef DIAGNOSTIC
160/*XXX*/		printf("Interpreting Ultrix label\n");
161#endif
162
163		lp->d_magic = DEC_LABEL_MAGIC;
164		lp->d_npartitions = 0;
165		for (part = 0;
166		     part <((MAXPARTITIONS<DEC_NUM_DISK_PARTS) ?
167			    MAXPARTITIONS : DEC_NUM_DISK_PARTS);
168		     part++) {
169			lp->d_partitions[part].p_size = dlp->map[part].numBlocks;
170			lp->d_partitions[part].p_offset = dlp->map[part].startBlock;
171			lp->d_partitions[part].p_fsize = 1024;
172			lp->d_partitions[part].p_fstype =
173			  (part==1) ? FS_SWAP : FS_BSDFFS;
174			lp->d_npartitions += 1;
175
176#ifdef DIAGNOSTIC
177			printf(" Ultrix label rz%d%c: start %d len %d\n",
178			       DISKUNIT(dev), "abcdefgh"[part],
179			       lp->d_partitions[part].p_offset,
180			       lp->d_partitions[part].p_size);
181#endif
182		}
183		break;
184	}
185
186done:
187	bp->b_flags = B_INVAL | B_AGE;
188	brelse(bp);
189	return (msg);
190}
191#endif /* COMPAT_ULTRIX */
192
193
194/*
195 * Check new disk label for sensibility
196 * before setting it.
197 */
198int
199setdisklabel(olp, nlp, openmask, osdep)
200	struct disklabel *olp, *nlp;
201	u_long openmask;
202	struct cpu_disklabel *osdep;
203{
204	int i;
205	struct partition *opp, *npp;
206
207	if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC ||
208	    dkcksum(nlp) != 0)
209		return (EINVAL);
210	while ((i = ffs((long)openmask)) != 0) {
211		i--;
212		openmask &= ~(1 << i);
213		if (nlp->d_npartitions <= i)
214			return (EBUSY);
215		opp = &olp->d_partitions[i];
216		npp = &nlp->d_partitions[i];
217		if (npp->p_offset != opp->p_offset || npp->p_size < opp->p_size)
218			return (EBUSY);
219		/*
220		 * Copy internally-set partition information
221		 * if new label doesn't include it.		XXX
222		 */
223		if (npp->p_fstype == FS_UNUSED && opp->p_fstype != FS_UNUSED) {
224			npp->p_fstype = opp->p_fstype;
225			npp->p_fsize = opp->p_fsize;
226			npp->p_frag = opp->p_frag;
227			npp->p_cpg = opp->p_cpg;
228		}
229	}
230 	nlp->d_checksum = 0;
231 	nlp->d_checksum = dkcksum(nlp);
232	*olp = *nlp;
233	return (0);
234}
235
236/* encoding of disk minor numbers, should be elsewhere... */
237#define dkunit(dev)		(minor(dev) >> 3)
238#define dkpart(dev)		(minor(dev) & 07)
239#define dkminor(unit, part)	(((unit) << 3) | (part))
240
241/*
242 * Write disk label back to device after modification.
243 */
244int
245writedisklabel(dev, strat, lp, osdep)
246	dev_t dev;
247	void (*strat) __P((struct buf *bp));
248	register struct disklabel *lp;
249	struct cpu_disklabel *osdep;
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	}
262	bp = geteblk((int)lp->d_secsize);
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);
268	if ((error = biowait(bp)) != 0)
269		goto done;
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);
279			error = biowait(bp);
280			goto done;
281		}
282	}
283	error = ESRCH;
284done:
285	brelse(bp);
286	return (error);
287}
288
289
290/*
291 * was this the boot device ?
292 */
293void
294dk_establish(dk, dev)
295	struct disk *dk;
296	struct device *dev;
297{
298	/* see also arch/alpha/alpha/disksubr.c */
299	printf("Warning: boot path unknown\n");
300	return;
301}
302
303/*
304 * UNTESTED !!
305 *
306 * Determine the size of the transfer, and make sure it is
307 * within the boundaries of the partition. Adjust transfer
308 * if needed, and signal errors or early completion.
309 */
310int
311bounds_check_with_label(bp, lp, wlabel)
312	struct buf *bp;
313	struct disklabel *lp;
314	int wlabel;
315{
316
317	struct partition *p = lp->d_partitions + dkpart(bp->b_dev);
318	int labelsect = lp->d_partitions[0].p_offset;
319	int maxsz = p->p_size;
320	int sz = (bp->b_bcount + DEV_BSIZE - 1) >> DEV_BSHIFT;
321
322	/* overwriting disk label ? */
323	/* XXX should also protect bootstrap in first 8K */
324	if (bp->b_blkno + p->p_offset <= LABELSECTOR + labelsect &&
325	    (bp->b_flags & B_READ) == 0 && wlabel == 0) {
326		bp->b_error = EROFS;
327		goto bad;
328	}
329
330	/* beyond partition? */
331	if (bp->b_blkno < 0 || bp->b_blkno + sz > maxsz) {
332		/* if exactly at end of disk, return an EOF */
333		if (bp->b_blkno == maxsz) {
334			bp->b_resid = bp->b_bcount;
335			return(0);
336		}
337		/* or truncate if part of it fits */
338		sz = maxsz - bp->b_blkno;
339		if (sz <= 0) {
340			bp->b_error = EINVAL;
341			goto bad;
342		}
343		bp->b_bcount = sz << DEV_BSHIFT;
344	}
345
346	/* calculate cylinder for disksort to order transfers with */
347	bp->b_resid = (bp->b_blkno + p->p_offset) / lp->d_secpercyl;
348	return(1);
349bad:
350	bp->b_flags |= B_ERROR;
351	return(-1);
352}
353