xref: /dragonfly/sys/kern/subr_diskslice.c (revision 1847e88f)
1 /*-
2  * Copyright (c) 1994 Bruce D. Evans.
3  * All rights reserved.
4  *
5  * Copyright (c) 1990 The Regents of the University of California.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * William Jolitz.
10  *
11  * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
12  * All rights reserved.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. All advertising materials mentioning features or use of this software
23  *    must display the following acknowledgement:
24  *	This product includes software developed by the University of
25  *	California, Berkeley and its contributors.
26  * 4. Neither the name of the University nor the names of its contributors
27  *    may be used to endorse or promote products derived from this software
28  *    without specific prior written permission.
29  *
30  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40  * SUCH DAMAGE.
41  *
42  *	from: @(#)wd.c	7.2 (Berkeley) 5/9/91
43  *	from: wd.c,v 1.55 1994/10/22 01:57:12 phk Exp $
44  *	from: @(#)ufs_disksubr.c	7.16 (Berkeley) 5/4/91
45  *	from: ufs_disksubr.c,v 1.8 1994/06/07 01:21:39 phk Exp $
46  * $FreeBSD: src/sys/kern/subr_diskslice.c,v 1.82.2.6 2001/07/24 09:49:41 dd Exp $
47  * $DragonFly: src/sys/kern/subr_diskslice.c,v 1.13 2006/02/17 19:18:06 dillon Exp $
48  */
49 
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/buf.h>
53 #include <sys/conf.h>
54 #include <sys/disklabel.h>
55 #include <sys/diskslice.h>
56 #include <sys/diskmbr.h>
57 #include <sys/fcntl.h>
58 #include <sys/malloc.h>
59 #include <sys/stat.h>
60 #include <sys/syslog.h>
61 #include <sys/vnode.h>
62 #include <sys/device.h>
63 #include <sys/thread2.h>
64 
65 #include <vfs/ufs/fs.h>
66 
67 #define TRACE(str)	do { if (ds_debug) printf str; } while (0)
68 
69 typedef	u_char	bool_t;
70 
71 static volatile bool_t ds_debug;
72 
73 static struct disklabel *clone_label (struct disklabel *lp);
74 static void dsiodone (struct bio *bio);
75 static char *fixlabel (char *sname, struct diskslice *sp,
76 			   struct disklabel *lp, int writeflag);
77 static void free_ds_label (struct diskslices *ssp, int slice);
78 static void partition_info (char *sname, int part, struct partition *pp);
79 static void slice_info (char *sname, struct diskslice *sp);
80 static void set_ds_label (struct diskslices *ssp, int slice,
81 			      struct disklabel *lp);
82 static void set_ds_wlabel (struct diskslices *ssp, int slice, int wlabel);
83 
84 /*
85  * Duplicate a label for the whole disk, and initialize defaults in the
86  * copy for fields that are not already initialized.  The caller only
87  * needs to initialize d_secsize and d_secperunit, and zero the fields
88  * that are to be defaulted.
89  */
90 static struct disklabel *
91 clone_label(struct disklabel *lp)
92 {
93 	struct disklabel *lp1;
94 
95 	lp1 = malloc(sizeof *lp1, M_DEVBUF, M_WAITOK);
96 	*lp1 = *lp;
97 	lp = NULL;
98 	if (lp1->d_typename[0] == '\0')
99 		strncpy(lp1->d_typename, "amnesiac", sizeof(lp1->d_typename));
100 	if (lp1->d_packname[0] == '\0')
101 		strncpy(lp1->d_packname, "fictitious", sizeof(lp1->d_packname));
102 	if (lp1->d_nsectors == 0)
103 		lp1->d_nsectors = 32;
104 	if (lp1->d_ntracks == 0)
105 		lp1->d_ntracks = 64;
106 	lp1->d_secpercyl = lp1->d_nsectors * lp1->d_ntracks;
107 	lp1->d_ncylinders = lp1->d_secperunit / lp1->d_secpercyl;
108 	if (lp1->d_rpm == 0)
109 		lp1->d_rpm = 3600;
110 	if (lp1->d_interleave == 0)
111 		lp1->d_interleave = 1;
112 	if (lp1->d_npartitions < RAW_PART + 1)
113 		lp1->d_npartitions = MAXPARTITIONS;
114 	if (lp1->d_bbsize == 0)
115 		lp1->d_bbsize = BBSIZE;
116 	if (lp1->d_sbsize == 0)
117 		lp1->d_sbsize = SBSIZE;
118 	lp1->d_partitions[RAW_PART].p_size = lp1->d_secperunit;
119 	lp1->d_magic = DISKMAGIC;
120 	lp1->d_magic2 = DISKMAGIC;
121 	lp1->d_checksum = dkcksum(lp1);
122 	return (lp1);
123 }
124 
125 /*
126  * Determine the size of the transfer, and make sure it is
127  * within the boundaries of the partition. Adjust transfer
128  * if needed, and signal errors or early completion.
129  *
130  * XXX TODO:
131  *	o Split buffers that are too big for the device.
132  *	o Check for overflow.
133  *	o Finish cleaning this up.
134  *
135  * This function returns 1 on success, 0 if transfer equates
136  * to EOF (end of disk) or -1 on failure.  The appropriate
137  * 'errno' value is also set in bp->b_error and bp->b_flags
138  * is marked with B_ERROR.
139  */
140 struct bio *
141 dscheck(dev_t dev, struct bio *bio, struct diskslices *ssp)
142 {
143 	struct buf *bp = bio->bio_buf;
144 	struct bio *nbio;
145 	daddr_t	blkno;
146 	u_long	endsecno;
147 	daddr_t	labelsect;
148 	struct disklabel *lp;
149 	char *msg;
150 	long nsec;
151 	struct partition *pp;
152 	daddr_t	secno;
153 	daddr_t	slicerel_secno;
154 	struct diskslice *sp;
155 
156 	blkno = bio->bio_blkno;
157 	if (blkno < 0) {
158 		printf("dscheck(%s): negative bio_blkno %ld\n",
159 		    devtoname(dev), (long)blkno);
160 		bp->b_error = EINVAL;
161 		goto bad;
162 	}
163 	sp = &ssp->dss_slices[dkslice(dev)];
164 	lp = sp->ds_label;
165 	if (ssp->dss_secmult == 1) {
166 		if (bp->b_bcount % (u_long)DEV_BSIZE)
167 			goto bad_bcount;
168 		secno = blkno;
169 		nsec = bp->b_bcount >> DEV_BSHIFT;
170 	} else if (ssp->dss_secshift != -1) {
171 		if (bp->b_bcount & (ssp->dss_secsize - 1))
172 			goto bad_bcount;
173 		if (blkno & (ssp->dss_secmult - 1))
174 			goto bad_blkno;
175 		secno = blkno >> ssp->dss_secshift;
176 		nsec = bp->b_bcount >> (DEV_BSHIFT + ssp->dss_secshift);
177 	} else {
178 		if (bp->b_bcount % ssp->dss_secsize)
179 			goto bad_bcount;
180 		if (blkno % ssp->dss_secmult)
181 			goto bad_blkno;
182 		secno = blkno / ssp->dss_secmult;
183 		nsec = bp->b_bcount / ssp->dss_secsize;
184 	}
185 	if (lp == NULL) {
186 		labelsect = -LABELSECTOR - 1;
187 		endsecno = sp->ds_size;
188 		slicerel_secno = secno;
189 	} else {
190 		labelsect = lp->d_partitions[LABEL_PART].p_offset;
191 		if (labelsect != 0)
192 			Debugger("labelsect != 0 in dscheck()");
193 		pp = &lp->d_partitions[dkpart(dev)];
194 		endsecno = pp->p_size;
195 		slicerel_secno = pp->p_offset + secno;
196 	}
197 
198 	/* overwriting disk label ? */
199 	/* XXX should also protect bootstrap in first 8K */
200 	if (slicerel_secno <= LABELSECTOR + labelsect &&
201 #if LABELSECTOR != 0
202 	    slicerel_secno + nsec > LABELSECTOR + labelsect &&
203 #endif
204 	    (bp->b_flags & B_READ) == 0 && sp->ds_wlabel == 0) {
205 		bp->b_error = EROFS;
206 		goto bad;
207 	}
208 
209 #if defined(DOSBBSECTOR) && defined(notyet)
210 	/* overwriting master boot record? */
211 	if (slicerel_secno <= DOSBBSECTOR && (bp->b_flags & B_READ) == 0 &&
212 	    sp->ds_wlabel == 0) {
213 		bp->b_error = EROFS;
214 		goto bad;
215 	}
216 #endif
217 
218 	/* beyond partition? */
219 	if (secno + nsec > endsecno) {
220 		/* if exactly at end of disk, return an EOF */
221 		if (secno == endsecno) {
222 			bp->b_resid = bp->b_bcount;
223 			return (0);
224 		}
225 		/* or truncate if part of it fits */
226 		nsec = endsecno - secno;
227 		if (nsec <= 0) {
228 			bp->b_error = EINVAL;
229 			goto bad;
230 		}
231 		bp->b_bcount = nsec * ssp->dss_secsize;
232 	}
233 
234 	nbio = push_bio(bio);
235 	nbio->bio_blkno = sp->ds_offset + slicerel_secno;
236 
237 	/*
238 	 * Snoop on label accesses if the slice offset is nonzero.  Fudge
239 	 * offsets in the label to keep the in-core label coherent with
240 	 * the on-disk one.
241 	 */
242 	if (slicerel_secno <= LABELSECTOR + labelsect
243 #if LABELSECTOR != 0
244 	    && slicerel_secno + nsec > LABELSECTOR + labelsect
245 #endif
246 	    && sp->ds_offset != 0) {
247 		nbio->bio_done = dsiodone;
248 		nbio->bio_caller_info1.ptr = sp;
249 		nbio->bio_caller_info2.offset = (off_t)(LABELSECTOR + labelsect -
250 					 slicerel_secno) * ssp->dss_secsize;
251 		if ((bp->b_flags & B_READ) == 0) {
252 			/*
253 			 * XXX even disklabel(8) writes directly so we need
254 			 * to adjust writes.  Perhaps we should drop support
255 			 * for DIOCWLABEL (always write protect labels) and
256 			 * require the use of DIOCWDINFO.
257 			 *
258 			 * XXX probably need to copy the data to avoid even
259 			 * temporarily corrupting the in-core copy.
260 			 */
261 			/* XXX need name here. */
262 			msg = fixlabel(
263 				NULL, sp,
264 			       (struct disklabel *)
265 			       (bp->b_data + (int)nbio->bio_caller_info2.offset),
266 			       TRUE);
267 			if (msg != NULL) {
268 				printf("dscheck(%s): %s\n",
269 				    devtoname(dev), msg);
270 				bp->b_error = EROFS;
271 				pop_bio(nbio);
272 				goto bad;
273 			}
274 		}
275 	}
276 	return (nbio);
277 
278 bad_bcount:
279 	printf(
280 	"dscheck(%s): b_bcount %ld is not on a sector boundary (ssize %d)\n",
281 	    devtoname(dev), bp->b_bcount, ssp->dss_secsize);
282 	bp->b_error = EINVAL;
283 	goto bad;
284 
285 bad_blkno:
286 	printf(
287 	"dscheck(%s): bio_blkno %ld is not on a sector boundary (ssize %d)\n",
288 	    devtoname(dev), (long)blkno, ssp->dss_secsize);
289 	bp->b_error = EINVAL;
290 	goto bad;
291 
292 bad:
293 	bp->b_resid = bp->b_bcount;
294 	bp->b_flags |= B_ERROR;
295 	return (NULL);
296 }
297 
298 void
299 dsclose(dev_t dev, int mode, struct diskslices *ssp)
300 {
301 	u_char mask;
302 	struct diskslice *sp;
303 
304 	sp = &ssp->dss_slices[dkslice(dev)];
305 	mask = 1 << dkpart(dev);
306 	sp->ds_openmask &= ~mask;
307 }
308 
309 void
310 dsgone(struct diskslices **sspp)
311 {
312 	int slice;
313 	struct diskslice *sp;
314 	struct diskslices *ssp;
315 
316 	for (slice = 0, ssp = *sspp; slice < ssp->dss_nslices; slice++) {
317 		sp = &ssp->dss_slices[slice];
318 		free_ds_label(ssp, slice);
319 	}
320 	free(ssp, M_DEVBUF);
321 	*sspp = NULL;
322 }
323 
324 /*
325  * For the "write" commands (DIOCSDINFO and DIOCWDINFO), this
326  * is subject to the same restriction as dsopen().
327  */
328 int
329 dsioctl(dev_t dev, u_long cmd, caddr_t data,
330 	int flags, struct diskslices **sspp)
331 {
332 	int error;
333 	struct disklabel *lp;
334 	int old_wlabel;
335 	u_char openmask;
336 	int part;
337 	int slice;
338 	struct diskslice *sp;
339 	struct diskslices *ssp;
340 	struct partition *pp;
341 
342 	slice = dkslice(dev);
343 	ssp = *sspp;
344 	sp = &ssp->dss_slices[slice];
345 	lp = sp->ds_label;
346 	switch (cmd) {
347 
348 	case DIOCGDVIRGIN:
349 		lp = (struct disklabel *)data;
350 		if (ssp->dss_slices[WHOLE_DISK_SLICE].ds_label) {
351 			*lp = *ssp->dss_slices[WHOLE_DISK_SLICE].ds_label;
352 		} else {
353 			bzero(lp, sizeof(struct disklabel));
354 		}
355 
356 		lp->d_magic = DISKMAGIC;
357 		lp->d_magic2 = DISKMAGIC;
358 		pp = &lp->d_partitions[RAW_PART];
359 		pp->p_offset = 0;
360 		pp->p_size = sp->ds_size;
361 
362 		lp->d_npartitions = MAXPARTITIONS;
363 		if (lp->d_interleave == 0)
364 			lp->d_interleave = 1;
365 		if (lp->d_rpm == 0)
366 			lp->d_rpm = 3600;
367 		if (lp->d_nsectors == 0)
368 			lp->d_nsectors = 32;
369 		if (lp->d_ntracks == 0)
370 			lp->d_ntracks = 64;
371 
372 		lp->d_bbsize = BBSIZE;
373 		lp->d_sbsize = SBSIZE;
374 		lp->d_secpercyl = lp->d_nsectors * lp->d_ntracks;
375 		lp->d_ncylinders = sp->ds_size / lp->d_secpercyl;
376 		lp->d_secperunit = sp->ds_size;
377 		lp->d_checksum = 0;
378 		lp->d_checksum = dkcksum(lp);
379 		return (0);
380 
381 	case DIOCGDINFO:
382 		if (lp == NULL)
383 			return (EINVAL);
384 		*(struct disklabel *)data = *lp;
385 		return (0);
386 
387 #ifdef notyet
388 	case DIOCGDINFOP:
389 		if (lp == NULL)
390 			return (EINVAL);
391 		*(struct disklabel **)data = lp;
392 		return (0);
393 #endif
394 
395 	case DIOCGPART:
396 		if (lp == NULL)
397 			return (EINVAL);
398 		((struct partinfo *)data)->disklab = lp;
399 		((struct partinfo *)data)->part
400 			= &lp->d_partitions[dkpart(dev)];
401 		return (0);
402 
403 	case DIOCGSLICEINFO:
404 		bcopy(ssp, data, (char *)&ssp->dss_slices[ssp->dss_nslices] -
405 				 (char *)ssp);
406 		return (0);
407 
408 	case DIOCSDINFO:
409 		if (slice == WHOLE_DISK_SLICE)
410 			return (ENODEV);
411 		if (!(flags & FWRITE))
412 			return (EBADF);
413 		lp = malloc(sizeof *lp, M_DEVBUF, M_WAITOK);
414 		if (sp->ds_label == NULL)
415 			bzero(lp, sizeof *lp);
416 		else
417 			bcopy(sp->ds_label, lp, sizeof *lp);
418 		if (sp->ds_label == NULL)
419 			openmask = 0;
420 		else {
421 			openmask = sp->ds_openmask;
422 			if (slice == COMPATIBILITY_SLICE)
423 				openmask |= ssp->dss_slices[
424 				    ssp->dss_first_bsd_slice].ds_openmask;
425 			else if (slice == ssp->dss_first_bsd_slice)
426 				openmask |= ssp->dss_slices[
427 				    COMPATIBILITY_SLICE].ds_openmask;
428 		}
429 		error = setdisklabel(lp, (struct disklabel *)data,
430 				     (u_long)openmask);
431 		/* XXX why doesn't setdisklabel() check this? */
432 		if (error == 0 && lp->d_partitions[RAW_PART].p_offset != 0)
433 			error = EXDEV;
434 		if (error == 0) {
435 			if (lp->d_secperunit > sp->ds_size)
436 				error = ENOSPC;
437 			for (part = 0; part < lp->d_npartitions; part++)
438 				if (lp->d_partitions[part].p_size > sp->ds_size)
439 					error = ENOSPC;
440 		}
441 		if (error != 0) {
442 			free(lp, M_DEVBUF);
443 			return (error);
444 		}
445 		free_ds_label(ssp, slice);
446 		set_ds_label(ssp, slice, lp);
447 		return (0);
448 
449 	case DIOCSYNCSLICEINFO:
450 		if (slice != WHOLE_DISK_SLICE || dkpart(dev) != RAW_PART)
451 			return (EINVAL);
452 		if (!*(int *)data)
453 			for (slice = 0; slice < ssp->dss_nslices; slice++) {
454 				openmask = ssp->dss_slices[slice].ds_openmask;
455 				if (openmask
456 				    && (slice != WHOLE_DISK_SLICE
457 					|| openmask & ~(1 << RAW_PART)))
458 					return (EBUSY);
459 			}
460 
461 		/*
462 		 * Temporarily forget the current slices struct and read
463 		 * the current one.
464 		 * XXX should wait for current accesses on this disk to
465 		 * complete, then lock out future accesses and opens.
466 		 */
467 		*sspp = NULL;
468 		lp = malloc(sizeof *lp, M_DEVBUF, M_WAITOK);
469 		*lp = *ssp->dss_slices[WHOLE_DISK_SLICE].ds_label;
470 		error = dsopen(dev, S_IFCHR, ssp->dss_oflags, sspp, lp);
471 		if (error != 0) {
472 			free(lp, M_DEVBUF);
473 			*sspp = ssp;
474 			return (error);
475 		}
476 
477 		/*
478 		 * Reopen everything.  This is a no-op except in the "force"
479 		 * case and when the raw bdev and cdev are both open.  Abort
480 		 * if anything fails.
481 		 */
482 		for (slice = 0; slice < ssp->dss_nslices; slice++) {
483 			for (openmask = ssp->dss_slices[slice].ds_openmask,
484 			     part = 0; openmask; openmask >>= 1, part++) {
485 				if (!(openmask & 1))
486 					continue;
487 				error = dsopen(dkmodslice(dkmodpart(dev, part),
488 							  slice),
489 					       S_IFCHR, ssp->dss_oflags, sspp,
490 					       lp);
491 				if (error != 0) {
492 					free(lp, M_DEVBUF);
493 					*sspp = ssp;
494 					return (EBUSY);
495 				}
496 			}
497 		}
498 
499 		free(lp, M_DEVBUF);
500 		dsgone(&ssp);
501 		return (0);
502 
503 	case DIOCWDINFO:
504 		error = dsioctl(dev, DIOCSDINFO, data, flags, &ssp);
505 		if (error != 0)
506 			return (error);
507 		/*
508 		 * XXX this used to hack on dk_openpart to fake opening
509 		 * partition 0 in case that is used instead of dkpart(dev).
510 		 */
511 		old_wlabel = sp->ds_wlabel;
512 		set_ds_wlabel(ssp, slice, TRUE);
513 		error = writedisklabel(dev, sp->ds_label);
514 		/* XXX should invalidate in-core label if write failed. */
515 		set_ds_wlabel(ssp, slice, old_wlabel);
516 		return (error);
517 
518 	case DIOCWLABEL:
519 		if (slice == WHOLE_DISK_SLICE)
520 			return (ENODEV);
521 		if (!(flags & FWRITE))
522 			return (EBADF);
523 		set_ds_wlabel(ssp, slice, *(int *)data != 0);
524 		return (0);
525 
526 	default:
527 		return (ENOIOCTL);
528 	}
529 }
530 
531 static void
532 dsiodone(struct bio *bio)
533 {
534 	struct buf *bp = bio->bio_buf;
535 	char *msg;
536 
537 	bp->b_flags = bp->b_flags & ~B_DONE;
538 	if (!(bp->b_flags & B_READ)
539 	    || (!(bp->b_flags & B_ERROR) && bp->b_error == 0)) {
540 		msg = fixlabel(NULL, bio->bio_caller_info1.ptr,
541 			       (struct disklabel *)
542 			       (bp->b_data + (int)bio->bio_caller_info2.offset),
543 			       FALSE);
544 		if (msg != NULL)
545 			printf("%s\n", msg);
546 	}
547 	biodone(bio->bio_prev);
548 }
549 
550 int
551 dsisopen(struct diskslices *ssp)
552 {
553 	int slice;
554 
555 	if (ssp == NULL)
556 		return (0);
557 	for (slice = 0; slice < ssp->dss_nslices; slice++) {
558 		if (ssp->dss_slices[slice].ds_openmask)
559 			return (1);
560 	}
561 	return (0);
562 }
563 
564 /*
565  * Allocate a slices "struct" and initialize it to contain only an empty
566  * compatibility slice (pointing to itself), a whole disk slice (covering
567  * the disk as described by the label), and (nslices - BASE_SLICES) empty
568  * slices beginning at BASE_SLICE.
569  */
570 struct diskslices *
571 dsmakeslicestruct(int nslices, struct disklabel *lp)
572 {
573 	struct diskslice *sp;
574 	struct diskslices *ssp;
575 
576 	ssp = malloc(offsetof(struct diskslices, dss_slices) +
577 		     nslices * sizeof *sp, M_DEVBUF, M_WAITOK);
578 	ssp->dss_first_bsd_slice = COMPATIBILITY_SLICE;
579 	ssp->dss_nslices = nslices;
580 	ssp->dss_oflags = 0;
581 	ssp->dss_secmult = lp->d_secsize / DEV_BSIZE;
582 	if (ssp->dss_secmult & (ssp->dss_secmult - 1))
583 		ssp->dss_secshift = -1;
584 	else
585 		ssp->dss_secshift = ffs(ssp->dss_secmult) - 1;
586 	ssp->dss_secsize = lp->d_secsize;
587 	sp = &ssp->dss_slices[0];
588 	bzero(sp, nslices * sizeof *sp);
589 	sp[WHOLE_DISK_SLICE].ds_size = lp->d_secperunit;
590 	return (ssp);
591 }
592 
593 char *
594 dsname(dev_t dev, int unit, int slice, int part, char *partname)
595 {
596 	static char name[32];
597 	const char *dname;
598 
599 	dname = dev_dname(dev);
600 	if (strlen(dname) > 16)
601 		dname = "nametoolong";
602 	snprintf(name, sizeof(name), "%s%d", dname, unit);
603 	partname[0] = '\0';
604 	if (slice != WHOLE_DISK_SLICE || part != RAW_PART) {
605 		partname[0] = 'a' + part;
606 		partname[1] = '\0';
607 		if (slice != COMPATIBILITY_SLICE) {
608 			snprintf(name + strlen(name),
609 			    sizeof(name) - strlen(name), "s%d", slice - 1);
610 		}
611 	}
612 	return (name);
613 }
614 
615 /*
616  * This should only be called when the unit is inactive and the strategy
617  * routine should not allow it to become active unless we call it.  Our
618  * strategy routine must be special to allow activity.
619  */
620 int
621 dsopen(dev_t dev, int mode, u_int flags,
622 	struct diskslices **sspp, struct disklabel *lp)
623 {
624 	dev_t dev1;
625 	int error;
626 	struct disklabel *lp1;
627 	char *msg;
628 	u_char mask;
629 	bool_t need_init;
630 	int part;
631 	char partname[2];
632 	int slice;
633 	char *sname;
634 	struct diskslice *sp;
635 	struct diskslices *ssp;
636 	int unit;
637 
638 	dev->si_bsize_phys = lp->d_secsize;
639 
640 	unit = dkunit(dev);
641 	if (lp->d_secsize % DEV_BSIZE) {
642 		printf("%s: invalid sector size %lu\n", devtoname(dev),
643 		    (u_long)lp->d_secsize);
644 		return (EINVAL);
645 	}
646 
647 	/*
648 	 * XXX reinitialize the slice table unless there is an open device
649 	 * on the unit.  This should only be done if the media has changed.
650 	 */
651 	ssp = *sspp;
652 	need_init = !dsisopen(ssp);
653 	if (ssp != NULL && need_init)
654 		dsgone(sspp);
655 	if (need_init) {
656 		/*
657 		 * Allocate a minimal slices "struct".  This will become
658 		 * the final slices "struct" if we don't want real slices
659 		 * or if we can't find any real slices.
660 		 */
661 		*sspp = dsmakeslicestruct(BASE_SLICE, lp);
662 
663 		if (!(flags & DSO_ONESLICE)) {
664 			TRACE(("dsinit\n"));
665 			error = dsinit(dev, lp, sspp);
666 			if (error != 0) {
667 				dsgone(sspp);
668 				return (error);
669 			}
670 		}
671 		ssp = *sspp;
672 		ssp->dss_oflags = flags;
673 
674 		/*
675 		 * If there are no real slices, then make the compatiblity
676 		 * slice cover the whole disk.
677 		 */
678 		if (ssp->dss_nslices == BASE_SLICE)
679 			ssp->dss_slices[COMPATIBILITY_SLICE].ds_size
680 				= lp->d_secperunit;
681 
682 		/* Point the compatibility slice at the BSD slice, if any. */
683 		for (slice = BASE_SLICE; slice < ssp->dss_nslices; slice++) {
684 			sp = &ssp->dss_slices[slice];
685 			if (sp->ds_type == DOSPTYP_386BSD /* XXX */) {
686 				ssp->dss_first_bsd_slice = slice;
687 				ssp->dss_slices[COMPATIBILITY_SLICE].ds_offset
688 					= sp->ds_offset;
689 				ssp->dss_slices[COMPATIBILITY_SLICE].ds_size
690 					= sp->ds_size;
691 				ssp->dss_slices[COMPATIBILITY_SLICE].ds_type
692 					= sp->ds_type;
693 				break;
694 			}
695 		}
696 
697 		ssp->dss_slices[WHOLE_DISK_SLICE].ds_label = clone_label(lp);
698 		ssp->dss_slices[WHOLE_DISK_SLICE].ds_wlabel = TRUE;
699 	}
700 
701 	/*
702 	 * Initialize secondary info for all slices.  It is needed for more
703 	 * than the current slice in the DEVFS case.  XXX DEVFS is no more.
704 	 */
705 	for (slice = 0; slice < ssp->dss_nslices; slice++) {
706 		sp = &ssp->dss_slices[slice];
707 		if (sp->ds_label != NULL)
708 			continue;
709 		dev1 = dkmodslice(dkmodpart(dev, RAW_PART), slice);
710 		sname = dsname(dev, unit, slice, RAW_PART, partname);
711 		/*
712 		 * XXX this should probably only be done for the need_init
713 		 * case, but there may be a problem with DIOCSYNCSLICEINFO.
714 		 */
715 		set_ds_wlabel(ssp, slice, TRUE);	/* XXX invert */
716 		lp1 = clone_label(lp);
717 		TRACE(("readdisklabel\n"));
718 		if (flags & DSO_NOLABELS)
719 			msg = NULL;
720 		else {
721 			msg = readdisklabel(dev1, lp1);
722 
723 			/*
724 			 * readdisklabel() returns NULL for success, and an
725 			 * error string for failure.
726 			 *
727 			 * If there isn't a label on the disk, and if the
728 			 * DSO_COMPATLABEL is set, we want to use the
729 			 * faked-up label provided by the caller.
730 			 *
731 			 * So we set msg to NULL to indicate that there is
732 			 * no failure (since we have a faked-up label),
733 			 * free lp1, and then clone it again from lp.
734 			 * (In case readdisklabel() modified lp1.)
735 			 */
736 			if (msg != NULL && (flags & DSO_COMPATLABEL)) {
737 				msg = NULL;
738 				free(lp1, M_DEVBUF);
739 				lp1 = clone_label(lp);
740 			}
741 		}
742 		if (msg == NULL)
743 			msg = fixlabel(sname, sp, lp1, FALSE);
744 		if (msg == NULL && lp1->d_secsize != ssp->dss_secsize)
745 			msg = "inconsistent sector size";
746 		if (msg != NULL) {
747 			if (sp->ds_type == DOSPTYP_386BSD /* XXX */)
748 				log(LOG_WARNING, "%s: cannot find label (%s)\n",
749 				    sname, msg);
750 			free(lp1, M_DEVBUF);
751 			continue;
752 		}
753 		if (lp1->d_flags & D_BADSECT) {
754 			log(LOG_ERR, "%s: bad sector table not supported\n",
755 			    sname);
756 			free(lp1, M_DEVBUF);
757 			continue;
758 		}
759 		set_ds_label(ssp, slice, lp1);
760 		set_ds_wlabel(ssp, slice, FALSE);
761 	}
762 
763 	slice = dkslice(dev);
764 	if (slice >= ssp->dss_nslices)
765 		return (ENXIO);
766 	sp = &ssp->dss_slices[slice];
767 	part = dkpart(dev);
768 	if (part != RAW_PART
769 	    && (sp->ds_label == NULL || part >= sp->ds_label->d_npartitions))
770 		return (EINVAL);	/* XXX needs translation */
771 	mask = 1 << part;
772 	sp->ds_openmask |= mask;
773 	return (0);
774 }
775 
776 int
777 dssize(dev_t dev, struct diskslices **sspp)
778 {
779 	struct disklabel *lp;
780 	int part;
781 	int slice;
782 	struct diskslices *ssp;
783 
784 	slice = dkslice(dev);
785 	part = dkpart(dev);
786 	ssp = *sspp;
787 	if (ssp == NULL || slice >= ssp->dss_nslices
788 	    || !(ssp->dss_slices[slice].ds_openmask & (1 << part))) {
789 		if (dev_dopen(dev, FREAD, S_IFCHR, NULL) != 0)
790 			return (-1);
791 		dev_dclose(dev, FREAD, S_IFCHR, NULL);
792 		ssp = *sspp;
793 	}
794 	lp = ssp->dss_slices[slice].ds_label;
795 	if (lp == NULL)
796 		return (-1);
797 	return ((int)lp->d_partitions[part].p_size);
798 }
799 
800 static void
801 free_ds_label(struct diskslices *ssp, int slice)
802 {
803 	struct disklabel *lp;
804 	struct diskslice *sp;
805 
806 	sp = &ssp->dss_slices[slice];
807 	lp = sp->ds_label;
808 	if (lp == NULL)
809 		return;
810 	free(lp, M_DEVBUF);
811 	set_ds_label(ssp, slice, (struct disklabel *)NULL);
812 }
813 
814 static char *
815 fixlabel(char *sname, struct diskslice *sp, struct disklabel *lp, int writeflag)
816 {
817 	u_long end;
818 	u_long offset;
819 	int part;
820 	struct partition *pp;
821 	u_long start;
822 	bool_t warned;
823 
824 	/* These errors "can't happen" so don't bother reporting details. */
825 	if (lp->d_magic != DISKMAGIC || lp->d_magic2 != DISKMAGIC)
826 		return ("fixlabel: invalid magic");
827 	if (dkcksum(lp) != 0)
828 		return ("fixlabel: invalid checksum");
829 
830 	pp = &lp->d_partitions[RAW_PART];
831 	if (writeflag) {
832 		start = 0;
833 		offset = sp->ds_offset;
834 	} else {
835 		start = sp->ds_offset;
836 		offset = -sp->ds_offset;
837 	}
838 	if (pp->p_offset != start) {
839 		if (sname != NULL) {
840 			printf(
841 "%s: rejecting BSD label: raw partition offset != slice offset\n",
842 			       sname);
843 			slice_info(sname, sp);
844 			partition_info(sname, RAW_PART, pp);
845 		}
846 		return ("fixlabel: raw partition offset != slice offset");
847 	}
848 	if (pp->p_size != sp->ds_size) {
849 		if (sname != NULL) {
850 			printf("%s: raw partition size != slice size\n", sname);
851 			slice_info(sname, sp);
852 			partition_info(sname, RAW_PART, pp);
853 		}
854 		if (pp->p_size > sp->ds_size) {
855 			if (sname == NULL)
856 				return ("fixlabel: raw partition size > slice size");
857 			printf("%s: truncating raw partition\n", sname);
858 			pp->p_size = sp->ds_size;
859 		}
860 	}
861 	end = start + sp->ds_size;
862 	if (start > end)
863 		return ("fixlabel: slice wraps");
864 	if (lp->d_secpercyl <= 0)
865 		return ("fixlabel: d_secpercyl <= 0");
866 	pp -= RAW_PART;
867 	warned = FALSE;
868 	for (part = 0; part < lp->d_npartitions; part++, pp++) {
869 		if (pp->p_offset != 0 || pp->p_size != 0) {
870 			if (pp->p_offset < start
871 			    || pp->p_offset + pp->p_size > end
872 			    || pp->p_offset + pp->p_size < pp->p_offset) {
873 				if (sname != NULL) {
874 					printf(
875 "%s: rejecting partition in BSD label: it isn't entirely within the slice\n",
876 					       sname);
877 					if (!warned) {
878 						slice_info(sname, sp);
879 						warned = TRUE;
880 					}
881 					partition_info(sname, part, pp);
882 				}
883 				/* XXX else silently discard junk. */
884 				bzero(pp, sizeof *pp);
885 			} else
886 				pp->p_offset += offset;
887 		}
888 	}
889 	lp->d_ncylinders = sp->ds_size / lp->d_secpercyl;
890 	lp->d_secperunit = sp->ds_size;
891  	lp->d_checksum = 0;
892  	lp->d_checksum = dkcksum(lp);
893 	return (NULL);
894 }
895 
896 static void
897 partition_info(char *sname, int part, struct partition *pp)
898 {
899 	printf("%s%c: start %lu, end %lu, size %lu\n", sname, 'a' + part,
900 	       (u_long)pp->p_offset, (u_long)(pp->p_offset + pp->p_size - 1),
901 	       (u_long)pp->p_size);
902 }
903 
904 static void
905 slice_info(char *sname, struct diskslice *sp)
906 {
907 	printf("%s: start %lu, end %lu, size %lu\n", sname,
908 	       sp->ds_offset, sp->ds_offset + sp->ds_size - 1, sp->ds_size);
909 }
910 
911 static void
912 set_ds_label(struct diskslices *ssp, int slice, struct disklabel *lp)
913 {
914 	ssp->dss_slices[slice].ds_label = lp;
915 	if (slice == COMPATIBILITY_SLICE)
916 		ssp->dss_slices[ssp->dss_first_bsd_slice].ds_label = lp;
917 	else if (slice == ssp->dss_first_bsd_slice)
918 		ssp->dss_slices[COMPATIBILITY_SLICE].ds_label = lp;
919 }
920 
921 static void
922 set_ds_wlabel(struct diskslices *ssp, int slice, int wlabel)
923 {
924 	ssp->dss_slices[slice].ds_wlabel = wlabel;
925 	if (slice == COMPATIBILITY_SLICE)
926 		ssp->dss_slices[ssp->dss_first_bsd_slice].ds_wlabel = wlabel;
927 	else if (slice == ssp->dss_first_bsd_slice)
928 		ssp->dss_slices[COMPATIBILITY_SLICE].ds_wlabel = wlabel;
929 }
930