xref: /netbsd/sys/dev/ld.c (revision c4a72b64)
1 /*	$NetBSD: ld.c,v 1.18 2002/11/01 11:31:56 mrg Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Doran and Charles M. Hannum.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Disk driver for use by RAID controllers.
41  */
42 
43 #include <sys/cdefs.h>
44 __KERNEL_RCSID(0, "$NetBSD: ld.c,v 1.18 2002/11/01 11:31:56 mrg Exp $");
45 
46 #include "rnd.h"
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/kernel.h>
51 #include <sys/device.h>
52 #include <sys/queue.h>
53 #include <sys/proc.h>
54 #include <sys/buf.h>
55 #include <sys/endian.h>
56 #include <sys/disklabel.h>
57 #include <sys/disk.h>
58 #include <sys/dkio.h>
59 #include <sys/stat.h>
60 #include <sys/lock.h>
61 #include <sys/conf.h>
62 #include <sys/fcntl.h>
63 #include <sys/vnode.h>
64 #include <sys/syslog.h>
65 #if NRND > 0
66 #include <sys/rnd.h>
67 #endif
68 
69 #include <dev/ldvar.h>
70 
71 static void	ldgetdefaultlabel(struct ld_softc *, struct disklabel *);
72 static void	ldgetdisklabel(struct ld_softc *);
73 static int	ldlock(struct ld_softc *);
74 static void	ldminphys(struct buf *bp);
75 static void	ldshutdown(void *);
76 static int	ldstart(struct ld_softc *, struct buf *);
77 static void	ldunlock(struct ld_softc *);
78 
79 extern struct	cfdriver ld_cd;
80 
81 dev_type_open(ldopen);
82 dev_type_close(ldclose);
83 dev_type_read(ldread);
84 dev_type_write(ldwrite);
85 dev_type_ioctl(ldioctl);
86 dev_type_strategy(ldstrategy);
87 dev_type_dump(lddump);
88 dev_type_size(ldsize);
89 
90 const struct bdevsw ld_bdevsw = {
91 	ldopen, ldclose, ldstrategy, ldioctl, lddump, ldsize, D_DISK
92 };
93 
94 const struct cdevsw ld_cdevsw = {
95 	ldopen, ldclose, ldread, ldwrite, ldioctl,
96 	nostop, notty, nopoll, nommap, nokqfilter, D_DISK
97 };
98 
99 static struct	dkdriver lddkdriver = { ldstrategy };
100 static void	*ld_sdh;
101 
102 void
103 ldattach(struct ld_softc *sc)
104 {
105 	char buf[9];
106 
107 	if ((sc->sc_flags & LDF_ENABLED) == 0) {
108 		printf("%s: disabled\n", sc->sc_dv.dv_xname);
109 		return;
110 	}
111 
112 	/* Initialise and attach the disk structure. */
113 	sc->sc_dk.dk_driver = &lddkdriver;
114 	sc->sc_dk.dk_name = sc->sc_dv.dv_xname;
115 	disk_attach(&sc->sc_dk);
116 
117 	if (sc->sc_maxxfer > MAXPHYS)
118 		sc->sc_maxxfer = MAXPHYS;
119 
120 	/* Build synthetic geometry. */
121 	if (sc->sc_secperunit <= 528 * 2048)		/* 528MB */
122 		sc->sc_nheads = 16;
123 	else if (sc->sc_secperunit <= 1024 * 2048)	/* 1GB */
124 		sc->sc_nheads = 32;
125 	else if (sc->sc_secperunit <= 21504 * 2048)	/* 21GB */
126 		sc->sc_nheads = 64;
127 	else if (sc->sc_secperunit <= 43008 * 2048)	/* 42GB */
128 		sc->sc_nheads = 128;
129 	else
130 		sc->sc_nheads = 255;
131 
132 	sc->sc_nsectors = 63;
133 	sc->sc_ncylinders = sc->sc_secperunit /
134 	    (sc->sc_nheads * sc->sc_nsectors);
135 
136 	format_bytes(buf, sizeof(buf), (u_int64_t)sc->sc_secperunit *
137 	    sc->sc_secsize);
138 	printf("%s: %s, %d cyl, %d head, %d sec, %d bytes/sect x %d sectors\n",
139 	    sc->sc_dv.dv_xname, buf, sc->sc_ncylinders, sc->sc_nheads,
140 	    sc->sc_nsectors, sc->sc_secsize, sc->sc_secperunit);
141 
142 #if NRND > 0
143 	/* Attach the device into the rnd source list. */
144 	rnd_attach_source(&sc->sc_rnd_source, sc->sc_dv.dv_xname,
145 	    RND_TYPE_DISK, 0);
146 #endif
147 
148 	/* Set the `shutdownhook'. */
149 	if (ld_sdh == NULL)
150 		ld_sdh = shutdownhook_establish(ldshutdown, NULL);
151 	bufq_alloc(&sc->sc_bufq, BUFQ_FCFS);
152 }
153 
154 int
155 ldadjqparam(struct ld_softc *sc, int max)
156 {
157 	int s, rv;
158 
159 	s = splbio();
160 	sc->sc_maxqueuecnt = max;
161 	if (sc->sc_queuecnt > max) {
162 		sc->sc_flags |= LDF_DRAIN;
163 		rv = tsleep(&sc->sc_queuecnt, PRIBIO, "lddrn", 30 * hz);
164 		sc->sc_flags &= ~LDF_DRAIN;
165 	} else
166 		rv = 0;
167 	splx(s);
168 
169 	return (rv);
170 }
171 
172 int
173 ldbegindetach(struct ld_softc *sc, int flags)
174 {
175 	int s, rv;
176 
177 	if ((sc->sc_flags & LDF_ENABLED) == 0)
178 		return (0);
179 
180 	if ((flags & DETACH_FORCE) == 0 && sc->sc_dk.dk_openmask != 0)
181 		return (EBUSY);
182 
183 	s = splbio();
184 	sc->sc_flags |= LDF_DETACH;
185 	rv = ldadjqparam(sc, 0);
186 	splx(s);
187 
188 	return (rv);
189 }
190 
191 void
192 ldenddetach(struct ld_softc *sc)
193 {
194 	struct buf *bp;
195 	int s, bmaj, cmaj, i, mn;
196 
197 	if ((sc->sc_flags & LDF_ENABLED) == 0)
198 		return;
199 
200 	/* Wait for commands queued with the hardware to complete. */
201 	if (sc->sc_queuecnt != 0)
202 		if (tsleep(&sc->sc_queuecnt, PRIBIO, "lddtch", 30 * hz))
203 			printf("%s: not drained\n", sc->sc_dv.dv_xname);
204 
205 	/* Locate the major numbers. */
206 	bmaj = bdevsw_lookup_major(&ld_bdevsw);
207 	cmaj = cdevsw_lookup_major(&ld_cdevsw);
208 
209 	/* Kill off any queued buffers. */
210 	s = splbio();
211 	while ((bp = BUFQ_GET(&sc->sc_bufq)) != NULL) {
212 		bp->b_error = EIO;
213 		bp->b_flags |= B_ERROR;
214 		bp->b_resid = bp->b_bcount;
215 		biodone(bp);
216 	}
217 	bufq_free(&sc->sc_bufq);
218 	splx(s);
219 
220 	/* Nuke the vnodes for any open instances. */
221 	for (i = 0; i < MAXPARTITIONS; i++) {
222 		mn = DISKMINOR(sc->sc_dv.dv_unit, i);
223 		vdevgone(bmaj, mn, mn, VBLK);
224 		vdevgone(cmaj, mn, mn, VCHR);
225 	}
226 
227 	/* Detach from the disk list. */
228 	disk_detach(&sc->sc_dk);
229 
230 #if NRND > 0
231 	/* Unhook the entropy source. */
232 	rnd_detach_source(&sc->sc_rnd_source);
233 #endif
234 
235 	/* Flush the device's cache. */
236 	if (sc->sc_flush != NULL)
237 		if ((*sc->sc_flush)(sc) != 0)
238 			printf("%s: unable to flush cache\n",
239 			    sc->sc_dv.dv_xname);
240 }
241 
242 /* ARGSUSED */
243 static void
244 ldshutdown(void *cookie)
245 {
246 	struct ld_softc *sc;
247 	int i;
248 
249 	for (i = 0; i < ld_cd.cd_ndevs; i++) {
250 		if ((sc = device_lookup(&ld_cd, i)) == NULL)
251 			continue;
252 		if (sc->sc_flush != NULL && (*sc->sc_flush)(sc) != 0)
253 			printf("%s: unable to flush cache\n",
254 			    sc->sc_dv.dv_xname);
255 	}
256 }
257 
258 /* ARGSUSED */
259 int
260 ldopen(dev_t dev, int flags, int fmt, struct proc *p)
261 {
262 	struct ld_softc *sc;
263 	int unit, part;
264 
265 	unit = DISKUNIT(dev);
266 	if ((sc = device_lookup(&ld_cd, unit))== NULL)
267 		return (ENXIO);
268 	if ((sc->sc_flags & LDF_ENABLED) == 0)
269 		return (ENODEV);
270 	part = DISKPART(dev);
271 	ldlock(sc);
272 
273 	if (sc->sc_dk.dk_openmask == 0)
274 		ldgetdisklabel(sc);
275 
276 	/* Check that the partition exists. */
277 	if (part != RAW_PART && (part >= sc->sc_dk.dk_label->d_npartitions ||
278 	    sc->sc_dk.dk_label->d_partitions[part].p_fstype == FS_UNUSED)) {
279 	     	ldunlock(sc);
280 		return (ENXIO);
281 	}
282 
283 	/* Ensure only one open at a time. */
284 	switch (fmt) {
285 	case S_IFCHR:
286 		sc->sc_dk.dk_copenmask |= (1 << part);
287 		break;
288 	case S_IFBLK:
289 		sc->sc_dk.dk_bopenmask |= (1 << part);
290 		break;
291 	}
292 	sc->sc_dk.dk_openmask =
293 	    sc->sc_dk.dk_copenmask | sc->sc_dk.dk_bopenmask;
294 
295 	ldunlock(sc);
296 	return (0);
297 }
298 
299 /* ARGSUSED */
300 int
301 ldclose(dev_t dev, int flags, int fmt, struct proc *p)
302 {
303 	struct ld_softc *sc;
304 	int part, unit;
305 
306 	unit = DISKUNIT(dev);
307 	part = DISKPART(dev);
308 	sc = device_lookup(&ld_cd, unit);
309 	ldlock(sc);
310 
311 	switch (fmt) {
312 	case S_IFCHR:
313 		sc->sc_dk.dk_copenmask &= ~(1 << part);
314 		break;
315 	case S_IFBLK:
316 		sc->sc_dk.dk_bopenmask &= ~(1 << part);
317 		break;
318 	}
319 	sc->sc_dk.dk_openmask =
320 	    sc->sc_dk.dk_copenmask | sc->sc_dk.dk_bopenmask;
321 
322 	if (sc->sc_dk.dk_openmask == 0 && sc->sc_flush != NULL)
323 		if ((*sc->sc_flush)(sc) != 0)
324 			printf("%s: unable to flush cache\n",
325 			    sc->sc_dv.dv_xname);
326 
327 	ldunlock(sc);
328 	return (0);
329 }
330 
331 /* ARGSUSED */
332 int
333 ldread(dev_t dev, struct uio *uio, int ioflag)
334 {
335 
336 	return (physio(ldstrategy, NULL, dev, B_READ, ldminphys, uio));
337 }
338 
339 /* ARGSUSED */
340 int
341 ldwrite(dev_t dev, struct uio *uio, int ioflag)
342 {
343 
344 	return (physio(ldstrategy, NULL, dev, B_WRITE, ldminphys, uio));
345 }
346 
347 /* ARGSUSED */
348 int
349 ldioctl(dev_t dev, u_long cmd, caddr_t addr, int32_t flag, struct proc *p)
350 {
351 	struct ld_softc *sc;
352 	int part, unit, error;
353 #ifdef __HAVE_OLD_DISKLABEL
354 	struct disklabel newlabel;
355 #endif
356 	struct disklabel *lp;
357 
358 	unit = DISKUNIT(dev);
359 	part = DISKPART(dev);
360 	sc = device_lookup(&ld_cd, unit);
361 	error = 0;
362 
363 	switch (cmd) {
364 	case DIOCGDINFO:
365 		memcpy(addr, sc->sc_dk.dk_label, sizeof(struct disklabel));
366 		return (0);
367 
368 #ifdef __HAVE_OLD_DISKLABEL
369 	case ODIOCGDINFO:
370 		newlabel = *(sc->sc_dk.dk_label);
371 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
372 			return ENOTTY;
373 		memcpy(addr, &newlabel, sizeof(struct olddisklabel));
374 		return (0);
375 #endif
376 
377 	case DIOCGPART:
378 		((struct partinfo *)addr)->disklab = sc->sc_dk.dk_label;
379 		((struct partinfo *)addr)->part =
380 		    &sc->sc_dk.dk_label->d_partitions[part];
381 		break;
382 
383 	case DIOCWDINFO:
384 	case DIOCSDINFO:
385 #ifdef __HAVE_OLD_DISKLABEL
386 	case ODIOCWDINFO:
387 	case ODIOCSDINFO:
388 
389 		if (cmd == ODIOCSDINFO || cmd == ODIOCWDINFO) {
390 			memset(&newlabel, 0, sizeof newlabel);
391 			memcpy(&newlabel, addr, sizeof (struct olddisklabel));
392 			lp = &newlabel;
393 		} else
394 #endif
395 		lp = (struct disklabel *)addr;
396 
397 		if ((flag & FWRITE) == 0)
398 			return (EBADF);
399 
400 		if ((error = ldlock(sc)) != 0)
401 			return (error);
402 		sc->sc_flags |= LDF_LABELLING;
403 
404 		error = setdisklabel(sc->sc_dk.dk_label,
405 		    lp, /*sc->sc_dk.dk_openmask : */0,
406 		    sc->sc_dk.dk_cpulabel);
407 		if (error == 0 && (cmd == DIOCWDINFO
408 #ifdef __HAVE_OLD_DISKLABEL
409 		    || cmd == ODIOCWDINFO
410 #endif
411 		    ))
412 			error = writedisklabel(
413 			    MAKEDISKDEV(major(dev), DISKUNIT(dev), RAW_PART),
414 			    ldstrategy, sc->sc_dk.dk_label,
415 			    sc->sc_dk.dk_cpulabel);
416 
417 		sc->sc_flags &= ~LDF_LABELLING;
418 		ldunlock(sc);
419 		break;
420 
421 	case DIOCWLABEL:
422 		if ((flag & FWRITE) == 0)
423 			return (EBADF);
424 		if (*(int *)addr)
425 			sc->sc_flags |= LDF_WLABEL;
426 		else
427 			sc->sc_flags &= ~LDF_WLABEL;
428 		break;
429 
430 	case DIOCGDEFLABEL:
431 		ldgetdefaultlabel(sc, (struct disklabel *)addr);
432 		break;
433 
434 #ifdef __HAVE_OLD_DISKLABEL
435 	case ODIOCGDEFLABEL:
436 		ldgetdefaultlabel(sc, &newlabel);
437 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
438 			return ENOTTY;
439 		memcpy(addr, &newlabel, sizeof (struct olddisklabel));
440 		break;
441 #endif
442 
443 	default:
444 		error = ENOTTY;
445 		break;
446 	}
447 
448 	return (error);
449 }
450 
451 void
452 ldstrategy(struct buf *bp)
453 {
454 	struct ld_softc *sc;
455 	int s;
456 
457 	sc = device_lookup(&ld_cd, DISKUNIT(bp->b_dev));
458 
459 	s = splbio();
460 	if (sc->sc_queuecnt >= sc->sc_maxqueuecnt) {
461 		BUFQ_PUT(&sc->sc_bufq, bp);
462 		splx(s);
463 		return;
464 	}
465 	splx(s);
466 	ldstart(sc, bp);
467 }
468 
469 static int
470 ldstart(struct ld_softc *sc, struct buf *bp)
471 {
472 	struct disklabel *lp;
473 	int part, s, rv;
474 
475 	if ((sc->sc_flags & LDF_DETACH) != 0) {
476 		bp->b_error = EIO;
477 		bp->b_flags |= B_ERROR;
478 		bp->b_resid = bp->b_bcount;
479 		biodone(bp);
480 		return (-1);
481 	}
482 
483 	part = DISKPART(bp->b_dev);
484 	lp = sc->sc_dk.dk_label;
485 
486 	/*
487 	 * The transfer must be a whole number of blocks and the offset must
488 	 * not be negative.
489 	 */
490 	if ((bp->b_bcount % lp->d_secsize) != 0 || bp->b_blkno < 0) {
491 		bp->b_flags |= B_ERROR;
492 		biodone(bp);
493 		return (-1);
494 	}
495 
496 	/*
497 	 * If it's a null transfer, return.
498 	 */
499 	if (bp->b_bcount == 0) {
500 		bp->b_resid = bp->b_bcount;
501 		biodone(bp);
502 		return (-1);
503 	}
504 
505 	/*
506 	 * Do bounds checking and adjust the transfer.  If error, process.
507 	 * If past the end of partition, just return.
508 	 */
509 	if (part != RAW_PART &&
510 	    bounds_check_with_label(bp, lp,
511 	    (sc->sc_flags & (LDF_WLABEL | LDF_LABELLING)) != 0) <= 0) {
512 		bp->b_resid = bp->b_bcount;
513 		biodone(bp);
514 		return (-1);
515 	}
516 
517 	/*
518 	 * Convert the logical block number to a physical one and put it in
519 	 * terms of the device's logical block size.
520 	 */
521 	if (lp->d_secsize >= DEV_BSIZE)
522 		bp->b_rawblkno = bp->b_blkno / (lp->d_secsize / DEV_BSIZE);
523 	else
524 		bp->b_rawblkno = bp->b_blkno * (DEV_BSIZE / lp->d_secsize);
525 
526 	if (part != RAW_PART)
527 		bp->b_rawblkno += lp->d_partitions[part].p_offset;
528 
529 	s = splbio();
530 	disk_busy(&sc->sc_dk);
531 	sc->sc_queuecnt++;
532 	splx(s);
533 
534 	if ((rv = (*sc->sc_start)(sc, bp)) != 0) {
535 		bp->b_error = rv;
536 		bp->b_flags |= B_ERROR;
537 		bp->b_resid = bp->b_bcount;
538 		s = splbio();
539 		lddone(sc, bp);
540 		splx(s);
541 	}
542 
543 	return (0);
544 }
545 
546 void
547 lddone(struct ld_softc *sc, struct buf *bp)
548 {
549 
550 	if ((bp->b_flags & B_ERROR) != 0) {
551 		diskerr(bp, "ld", "error", LOG_PRINTF, 0, sc->sc_dk.dk_label);
552 		printf("\n");
553 	}
554 
555 	disk_unbusy(&sc->sc_dk, bp->b_bcount - bp->b_resid,
556 	    (bp->b_flags & B_READ));
557 #if NRND > 0
558 	rnd_add_uint32(&sc->sc_rnd_source, bp->b_rawblkno);
559 #endif
560 	biodone(bp);
561 
562 	if (--sc->sc_queuecnt <= sc->sc_maxqueuecnt) {
563 		if ((sc->sc_flags & LDF_DRAIN) != 0)
564 			wakeup(&sc->sc_queuecnt);
565 		while ((bp = BUFQ_GET(&sc->sc_bufq)) != NULL) {
566 			if (!ldstart(sc, bp))
567 				break;
568 		}
569 	}
570 }
571 
572 int
573 ldsize(dev_t dev)
574 {
575 	struct ld_softc *sc;
576 	int part, unit, omask, size;
577 
578 	unit = DISKUNIT(dev);
579 	if ((sc = device_lookup(&ld_cd, unit)) == NULL)
580 		return (ENODEV);
581 	if ((sc->sc_flags & LDF_ENABLED) == 0)
582 		return (ENODEV);
583 	part = DISKPART(dev);
584 
585 	omask = sc->sc_dk.dk_openmask & (1 << part);
586 
587 	if (omask == 0 && ldopen(dev, 0, S_IFBLK, NULL) != 0)
588 		return (-1);
589 	else if (sc->sc_dk.dk_label->d_partitions[part].p_fstype != FS_SWAP)
590 		size = -1;
591 	else
592 		size = sc->sc_dk.dk_label->d_partitions[part].p_size *
593 		    (sc->sc_dk.dk_label->d_secsize / DEV_BSIZE);
594 	if (omask == 0 && ldclose(dev, 0, S_IFBLK, NULL) != 0)
595 		return (-1);
596 
597 	return (size);
598 }
599 
600 /*
601  * Load the label information from the specified device.
602  */
603 static void
604 ldgetdisklabel(struct ld_softc *sc)
605 {
606 	const char *errstring;
607 
608 	ldgetdefaultlabel(sc, sc->sc_dk.dk_label);
609 
610 	/* Call the generic disklabel extraction routine. */
611 	errstring = readdisklabel(MAKEDISKDEV(0, sc->sc_dv.dv_unit, RAW_PART),
612 	    ldstrategy, sc->sc_dk.dk_label, sc->sc_dk.dk_cpulabel);
613 	if (errstring != NULL)
614 		printf("%s: %s\n", sc->sc_dv.dv_xname, errstring);
615 }
616 
617 /*
618  * Construct a ficticious label.
619  */
620 static void
621 ldgetdefaultlabel(struct ld_softc *sc, struct disklabel *lp)
622 {
623 
624 	memset(lp, 0, sizeof(struct disklabel));
625 
626 	lp->d_secsize = sc->sc_secsize;
627 	lp->d_ntracks = sc->sc_nheads;
628 	lp->d_nsectors = sc->sc_nsectors;
629 	lp->d_ncylinders = sc->sc_ncylinders;
630 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
631 	lp->d_type = DTYPE_LD;
632 	strcpy(lp->d_typename, "unknown");
633 	strcpy(lp->d_packname, "fictitious");
634 	lp->d_secperunit = sc->sc_secperunit;
635 	lp->d_rpm = 7200;
636 	lp->d_interleave = 1;
637 	lp->d_flags = 0;
638 
639 	lp->d_partitions[RAW_PART].p_offset = 0;
640 	lp->d_partitions[RAW_PART].p_size =
641 	    lp->d_secperunit * (lp->d_secsize / DEV_BSIZE);
642 	lp->d_partitions[RAW_PART].p_fstype = FS_UNUSED;
643 	lp->d_npartitions = RAW_PART + 1;
644 
645 	lp->d_magic = DISKMAGIC;
646 	lp->d_magic2 = DISKMAGIC;
647 	lp->d_checksum = dkcksum(lp);
648 }
649 
650 /*
651  * Wait interruptibly for an exclusive lock.
652  *
653  * XXX Several drivers do this; it should be abstracted and made MP-safe.
654  */
655 static int
656 ldlock(struct ld_softc *sc)
657 {
658 	int error;
659 
660 	while ((sc->sc_flags & LDF_LKHELD) != 0) {
661 		sc->sc_flags |= LDF_LKWANTED;
662 		if ((error = tsleep(sc, PRIBIO | PCATCH, "ldlck", 0)) != 0)
663 			return (error);
664 	}
665 	sc->sc_flags |= LDF_LKHELD;
666 	return (0);
667 }
668 
669 /*
670  * Unlock and wake up any waiters.
671  */
672 static void
673 ldunlock(struct ld_softc *sc)
674 {
675 
676 	sc->sc_flags &= ~LDF_LKHELD;
677 	if ((sc->sc_flags & LDF_LKWANTED) != 0) {
678 		sc->sc_flags &= ~LDF_LKWANTED;
679 		wakeup(sc);
680 	}
681 }
682 
683 /*
684  * Take a dump.
685  */
686 int
687 lddump(dev_t dev, daddr_t blkno, caddr_t va, size_t size)
688 {
689 	struct ld_softc *sc;
690 	struct disklabel *lp;
691 	int unit, part, nsects, sectoff, towrt, nblk, maxblkcnt, rv;
692 	static int dumping;
693 
694 	unit = DISKUNIT(dev);
695 	if ((sc = device_lookup(&ld_cd, unit)) == NULL)
696 		return (ENXIO);
697 	if ((sc->sc_flags & LDF_ENABLED) == 0)
698 		return (ENODEV);
699 	if (sc->sc_dump == NULL)
700 		return (ENXIO);
701 
702 	/* Check if recursive dump; if so, punt. */
703 	if (dumping)
704 		return (EFAULT);
705 	dumping = 1;
706 
707 	/* Convert to disk sectors.  Request must be a multiple of size. */
708 	part = DISKPART(dev);
709 	lp = sc->sc_dk.dk_label;
710 	if ((size % lp->d_secsize) != 0)
711 		return (EFAULT);
712 	towrt = size / lp->d_secsize;
713 	blkno = dbtob(blkno) / lp->d_secsize;	/* blkno in DEV_BSIZE units */
714 
715 	nsects = lp->d_partitions[part].p_size;
716 	sectoff = lp->d_partitions[part].p_offset;
717 
718 	/* Check transfer bounds against partition size. */
719 	if ((blkno < 0) || ((blkno + towrt) > nsects))
720 		return (EINVAL);
721 
722 	/* Offset block number to start of partition. */
723 	blkno += sectoff;
724 
725 	/* Start dumping and return when done. */
726 	maxblkcnt = sc->sc_maxxfer / sc->sc_secsize - 1;
727 	while (towrt > 0) {
728 		nblk = min(maxblkcnt, towrt);
729 
730 		if ((rv = (*sc->sc_dump)(sc, va, blkno, nblk)) != 0)
731 			return (rv);
732 
733 		towrt -= nblk;
734 		blkno += nblk;
735 		va += nblk * sc->sc_secsize;
736 	}
737 
738 	dumping = 0;
739 	return (0);
740 }
741 
742 /*
743  * Adjust the size of a transfer.
744  */
745 static void
746 ldminphys(struct buf *bp)
747 {
748 	struct ld_softc *sc;
749 
750 	sc = device_lookup(&ld_cd, DISKUNIT(bp->b_dev));
751 
752 	if (bp->b_bcount > sc->sc_maxxfer)
753 		bp->b_bcount = sc->sc_maxxfer;
754 	minphys(bp);
755 }
756