disksubr.c revision 1.40
1/*	$NetBSD: disksubr.c,v 1.40 2003/07/15 02:54:40 lukem 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/cdefs.h>
39__KERNEL_RCSID(0, "$NetBSD: disksubr.c,v 1.40 2003/07/15 02:54:40 lukem Exp $");
40
41#include "opt_compat_ultrix.h"
42
43#include <sys/param.h>
44#include <sys/systm.h>
45#include <sys/buf.h>
46#include <sys/disk.h>
47#include <sys/disklabel.h>
48
49#ifdef COMPAT_ULTRIX
50#include <dev/dec/dec_boot.h>
51#include <ufs/ufs/dinode.h>		/* XXX for fs.h */
52#include <ufs/ffs/fs.h>			/* XXX for BBSIZE & SBSIZE */
53
54char	*compat_label __P((dev_t dev, void (*strat) __P((struct buf *bp)),
55	    struct disklabel *lp, struct cpu_disklabel *osdep));	/* XXX */
56
57#endif
58
59/*
60 * Attempt to read a disk label from a device
61 * using the indicated strategy routine.
62 * The label must be partly set up before this:
63 * secpercyl and anything required in the strategy routine
64 * (e.g., sector size) must be filled in before calling us.
65 * Returns null on success and an error string on failure.
66 */
67const char *
68readdisklabel(dev, strat, lp, osdep)
69	dev_t dev;
70	void (*strat) __P((struct buf *bp));
71	struct disklabel *lp;
72	struct cpu_disklabel *osdep;
73{
74	struct buf *bp;
75	struct disklabel *dlp;
76	char *msg = NULL;
77
78	if (lp->d_secperunit == 0)
79		lp->d_secperunit = 0x1fffffff;
80	lp->d_npartitions = 1;
81	if (lp->d_partitions[0].p_size == 0)
82		lp->d_partitions[0].p_size = 0x1fffffff;
83	lp->d_partitions[0].p_offset = 0;
84
85	bp = geteblk((int)lp->d_secsize);
86	bp->b_dev = dev;
87	bp->b_blkno = LABELSECTOR;
88	bp->b_bcount = lp->d_secsize;
89	bp->b_flags |= B_READ;
90	bp->b_cylinder = LABELSECTOR / lp->d_secpercyl;
91	(*strat)(bp);
92	if (biowait(bp)) {
93		msg = "I/O error";
94	} else for (dlp = (struct disklabel *)bp->b_data;
95	    dlp <= (struct disklabel *)(bp->b_data+DEV_BSIZE-sizeof(*dlp));
96	    dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
97		if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) {
98			if (msg == NULL)
99				msg = "no disk label";
100		} else if (dlp->d_npartitions > MAXPARTITIONS ||
101			   dkcksum(dlp) != 0)
102			msg = "disk label corrupted";
103		else {
104			*lp = *dlp;
105			msg = NULL;
106			break;
107		}
108	}
109	brelse(bp);
110#ifdef COMPAT_ULTRIX
111	/*
112	 * If no NetBSD label was found, check for an Ultrix label and
113	 * construct tne incore label from the Ultrix partition information.
114	 */
115	if (msg != NULL) {
116		msg = compat_label(dev, strat, lp, osdep);
117		if (msg == NULL) {
118			printf("WARNING: using Ultrix partition information\n");
119			/* set geometry? */
120		}
121	}
122#endif
123/* XXX If no NetBSD label or Ultrix label found, generate default label here */
124	return (msg);
125}
126
127#ifdef COMPAT_ULTRIX
128/*
129 * Given a buffer bp, try and interpret it as an Ultrix disk label,
130 * putting the partition info into a native NetBSD label
131 */
132char *
133compat_label(dev, strat, lp, osdep)
134	dev_t dev;
135	void (*strat) __P((struct buf *bp));
136	struct disklabel *lp;
137	struct cpu_disklabel *osdep;
138{
139	dec_disklabel *dlp;
140	struct buf *bp = NULL;
141	char *msg = NULL;
142
143	bp = geteblk((int)lp->d_secsize);
144	bp->b_dev = dev;
145	bp->b_blkno = DEC_LABEL_SECTOR;
146	bp->b_bcount = lp->d_secsize;
147	bp->b_flags |= B_READ;
148	bp->b_cylinder = DEC_LABEL_SECTOR / lp->d_secpercyl;
149	(*strat)(bp);
150
151	if (biowait(bp)) {
152                msg = "I/O error";
153		goto done;
154	}
155
156	for (dlp = (dec_disklabel *)bp->b_data;
157	     dlp <= (dec_disklabel *)(bp->b_data+DEV_BSIZE-sizeof(*dlp));
158	     dlp = (dec_disklabel *)((char *)dlp + sizeof(long))) {
159
160		int part;
161
162		if (dlp->magic != DEC_LABEL_MAGIC) {
163			printf("label: %x\n",dlp->magic);
164			msg = ((msg != NULL) ? msg: "no disk label");
165			goto done;
166		}
167
168#ifdef DIAGNOSTIC
169/*XXX*/		printf("Interpreting Ultrix label\n");
170#endif
171
172		lp->d_magic = DEC_LABEL_MAGIC;
173		lp->d_npartitions = 0;
174		strncpy(lp->d_packname, "Ultrix label", 16);
175		lp->d_rpm = 3600;
176		lp->d_interleave = 1;
177		lp->d_flags = 0;
178		lp->d_bbsize = BBSIZE;
179		lp->d_sbsize = SBLOCKSIZE;
180		for (part = 0;
181		     part <((MAXPARTITIONS<DEC_NUM_DISK_PARTS) ?
182			    MAXPARTITIONS : DEC_NUM_DISK_PARTS);
183		     part++) {
184			lp->d_partitions[part].p_size = dlp->map[part].num_blocks;
185			lp->d_partitions[part].p_offset = dlp->map[part].start_block;
186			lp->d_partitions[part].p_fsize = 1024;
187			lp->d_partitions[part].p_fstype =
188			  (part==1) ? FS_SWAP : FS_BSDFFS;
189			lp->d_npartitions += 1;
190
191#ifdef DIAGNOSTIC
192			printf(" Ultrix label rz%d%c: start %d len %d\n",
193			       DISKUNIT(dev), "abcdefgh"[part],
194			       lp->d_partitions[part].p_offset,
195			       lp->d_partitions[part].p_size);
196#endif
197		}
198		break;
199	}
200
201done:
202	brelse(bp);
203	return (msg);
204}
205#endif /* COMPAT_ULTRIX */
206
207
208/*
209 * Check new disk label for sensibility
210 * before setting it.
211 */
212int
213setdisklabel(olp, nlp, openmask, osdep)
214	struct disklabel *olp, *nlp;
215	u_long openmask;
216	struct cpu_disklabel *osdep;
217{
218	int i;
219	struct partition *opp, *npp;
220
221	if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC ||
222	    dkcksum(nlp) != 0)
223		return (EINVAL);
224	while ((i = ffs(openmask)) != 0) {
225		i--;
226		openmask &= ~(1 << i);
227		if (nlp->d_npartitions <= i)
228			return (EBUSY);
229		opp = &olp->d_partitions[i];
230		npp = &nlp->d_partitions[i];
231		if (npp->p_offset != opp->p_offset || npp->p_size < opp->p_size)
232			return (EBUSY);
233		/*
234		 * Copy internally-set partition information
235		 * if new label doesn't include it.		XXX
236		 */
237		if (npp->p_fstype == FS_UNUSED && opp->p_fstype != FS_UNUSED) {
238			npp->p_fstype = opp->p_fstype;
239			npp->p_fsize = opp->p_fsize;
240			npp->p_frag = opp->p_frag;
241			npp->p_cpg = opp->p_cpg;
242		}
243	}
244 	nlp->d_checksum = 0;
245 	nlp->d_checksum = dkcksum(nlp);
246	*olp = *nlp;
247	return (0);
248}
249
250/*
251 * Write disk label back to device after modification.
252 */
253int
254writedisklabel(dev, strat, lp, osdep)
255	dev_t dev;
256	void (*strat) __P((struct buf *bp));
257	struct disklabel *lp;
258	struct cpu_disklabel *osdep;
259{
260	struct buf *bp;
261	struct disklabel *dlp;
262	int labelpart;
263	int error = 0;
264
265	labelpart = DISKPART(dev);
266	if (lp->d_partitions[labelpart].p_offset != 0) {
267		if (lp->d_partitions[0].p_offset != 0)
268			return (EXDEV);			/* not quite right */
269		labelpart = 0;
270	}
271	bp = geteblk((int)lp->d_secsize);
272	bp->b_dev = makedev(major(dev), DISKMINOR(DISKUNIT(dev), labelpart));
273	bp->b_blkno = LABELSECTOR;
274	bp->b_bcount = lp->d_secsize;
275	bp->b_flags |= B_READ;
276	(*strat)(bp);
277	if ((error = biowait(bp)) != 0)
278		goto done;
279	for (dlp = (struct disklabel *)bp->b_data;
280	    dlp <= (struct disklabel *)
281	      (bp->b_data + lp->d_secsize - sizeof(*dlp));
282	    dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
283		if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC &&
284		    dkcksum(dlp) == 0) {
285			*dlp = *lp;
286			bp->b_flags &= ~(B_READ|B_DONE);
287			bp->b_flags |= B_WRITE;
288			(*strat)(bp);
289			error = biowait(bp);
290			goto done;
291		}
292	}
293	error = ESRCH;
294done:
295	brelse(bp);
296	return (error);
297}
298
299/*
300 * UNTESTED !!
301 *
302 * Determine the size of the transfer, and make sure it is
303 * within the boundaries of the partition. Adjust transfer
304 * if needed, and signal errors or early completion.
305 */
306int
307bounds_check_with_label(dk, bp, wlabel)
308	struct disk *dk;
309	struct buf *bp;
310	int wlabel;
311{
312	struct disklabel *lp = dk->dk_label;
313	struct partition *p = lp->d_partitions + DISKPART(bp->b_dev);
314	int labelsect = lp->d_partitions[RAW_PART].p_offset;
315	int maxsz = p->p_size;
316	int sz = (bp->b_bcount + DEV_BSIZE - 1) >> DEV_BSHIFT;
317
318	/* overwriting disk label ? */
319	/* XXX should also protect bootstrap in first 8K */
320	if (bp->b_blkno + p->p_offset <= LABELSECTOR + labelsect &&
321	    (bp->b_flags & B_READ) == 0 && wlabel == 0) {
322		bp->b_error = EROFS;
323		goto bad;
324	}
325
326	/* beyond partition? */
327	if (bp->b_blkno < 0 || bp->b_blkno + sz > maxsz) {
328		/* if exactly at end of disk, return an EOF */
329		if (bp->b_blkno == maxsz) {
330			bp->b_resid = bp->b_bcount;
331			return(0);
332		}
333		/* or truncate if part of it fits */
334		sz = maxsz - bp->b_blkno;
335		if (sz <= 0) {
336			bp->b_error = EINVAL;
337			goto bad;
338		}
339		bp->b_bcount = sz << DEV_BSHIFT;
340	}
341
342	/* calculate cylinder for disksort to order transfers with */
343	bp->b_resid = (bp->b_blkno + p->p_offset) / lp->d_secpercyl;
344	return(1);
345bad:
346	bp->b_flags |= B_ERROR;
347	return(-1);
348}
349