xref: /netbsd-src/sys/dev/ld.c (revision 1ffa7b76c40339c17a0fb2a09fac93f287cfc046)
1 /*	$NetBSD: ld.c,v 1.19 2003/01/27 02:43:30 thorpej 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 1.19 2003/01/27 02:43:30 thorpej 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 if necessary. */
121 	if (sc->sc_nheads == 0 || sc->sc_nsectors == 0 ||
122 	    sc->sc_ncylinders == 0) {
123 		if (sc->sc_secperunit <= 528 * 2048)		/* 528MB */
124 			sc->sc_nheads = 16;
125 		else if (sc->sc_secperunit <= 1024 * 2048)	/* 1GB */
126 			sc->sc_nheads = 32;
127 		else if (sc->sc_secperunit <= 21504 * 2048)	/* 21GB */
128 			sc->sc_nheads = 64;
129 		else if (sc->sc_secperunit <= 43008 * 2048)	/* 42GB */
130 			sc->sc_nheads = 128;
131 		else
132 			sc->sc_nheads = 255;
133 
134 		sc->sc_nsectors = 63;
135 		sc->sc_ncylinders = sc->sc_secperunit /
136 		    (sc->sc_nheads * sc->sc_nsectors);
137 	}
138 
139 	format_bytes(buf, sizeof(buf), (u_int64_t)sc->sc_secperunit *
140 	    sc->sc_secsize);
141 	printf("%s: %s, %d cyl, %d head, %d sec, %d bytes/sect x %d sectors\n",
142 	    sc->sc_dv.dv_xname, buf, sc->sc_ncylinders, sc->sc_nheads,
143 	    sc->sc_nsectors, sc->sc_secsize, sc->sc_secperunit);
144 
145 #if NRND > 0
146 	/* Attach the device into the rnd source list. */
147 	rnd_attach_source(&sc->sc_rnd_source, sc->sc_dv.dv_xname,
148 	    RND_TYPE_DISK, 0);
149 #endif
150 
151 	/* Set the `shutdownhook'. */
152 	if (ld_sdh == NULL)
153 		ld_sdh = shutdownhook_establish(ldshutdown, NULL);
154 	bufq_alloc(&sc->sc_bufq, BUFQ_FCFS);
155 }
156 
157 int
158 ldadjqparam(struct ld_softc *sc, int max)
159 {
160 	int s, rv;
161 
162 	s = splbio();
163 	sc->sc_maxqueuecnt = max;
164 	if (sc->sc_queuecnt > max) {
165 		sc->sc_flags |= LDF_DRAIN;
166 		rv = tsleep(&sc->sc_queuecnt, PRIBIO, "lddrn", 30 * hz);
167 		sc->sc_flags &= ~LDF_DRAIN;
168 	} else
169 		rv = 0;
170 	splx(s);
171 
172 	return (rv);
173 }
174 
175 int
176 ldbegindetach(struct ld_softc *sc, int flags)
177 {
178 	int s, rv;
179 
180 	if ((sc->sc_flags & LDF_ENABLED) == 0)
181 		return (0);
182 
183 	if ((flags & DETACH_FORCE) == 0 && sc->sc_dk.dk_openmask != 0)
184 		return (EBUSY);
185 
186 	s = splbio();
187 	sc->sc_flags |= LDF_DETACH;
188 	rv = ldadjqparam(sc, 0);
189 	splx(s);
190 
191 	return (rv);
192 }
193 
194 void
195 ldenddetach(struct ld_softc *sc)
196 {
197 	struct buf *bp;
198 	int s, bmaj, cmaj, i, mn;
199 
200 	if ((sc->sc_flags & LDF_ENABLED) == 0)
201 		return;
202 
203 	/* Wait for commands queued with the hardware to complete. */
204 	if (sc->sc_queuecnt != 0)
205 		if (tsleep(&sc->sc_queuecnt, PRIBIO, "lddtch", 30 * hz))
206 			printf("%s: not drained\n", sc->sc_dv.dv_xname);
207 
208 	/* Locate the major numbers. */
209 	bmaj = bdevsw_lookup_major(&ld_bdevsw);
210 	cmaj = cdevsw_lookup_major(&ld_cdevsw);
211 
212 	/* Kill off any queued buffers. */
213 	s = splbio();
214 	while ((bp = BUFQ_GET(&sc->sc_bufq)) != NULL) {
215 		bp->b_error = EIO;
216 		bp->b_flags |= B_ERROR;
217 		bp->b_resid = bp->b_bcount;
218 		biodone(bp);
219 	}
220 	bufq_free(&sc->sc_bufq);
221 	splx(s);
222 
223 	/* Nuke the vnodes for any open instances. */
224 	for (i = 0; i < MAXPARTITIONS; i++) {
225 		mn = DISKMINOR(sc->sc_dv.dv_unit, i);
226 		vdevgone(bmaj, mn, mn, VBLK);
227 		vdevgone(cmaj, mn, mn, VCHR);
228 	}
229 
230 	/* Detach from the disk list. */
231 	disk_detach(&sc->sc_dk);
232 
233 #if NRND > 0
234 	/* Unhook the entropy source. */
235 	rnd_detach_source(&sc->sc_rnd_source);
236 #endif
237 
238 	/* Flush the device's cache. */
239 	if (sc->sc_flush != NULL)
240 		if ((*sc->sc_flush)(sc) != 0)
241 			printf("%s: unable to flush cache\n",
242 			    sc->sc_dv.dv_xname);
243 }
244 
245 /* ARGSUSED */
246 static void
247 ldshutdown(void *cookie)
248 {
249 	struct ld_softc *sc;
250 	int i;
251 
252 	for (i = 0; i < ld_cd.cd_ndevs; i++) {
253 		if ((sc = device_lookup(&ld_cd, i)) == NULL)
254 			continue;
255 		if (sc->sc_flush != NULL && (*sc->sc_flush)(sc) != 0)
256 			printf("%s: unable to flush cache\n",
257 			    sc->sc_dv.dv_xname);
258 	}
259 }
260 
261 /* ARGSUSED */
262 int
263 ldopen(dev_t dev, int flags, int fmt, struct proc *p)
264 {
265 	struct ld_softc *sc;
266 	int unit, part;
267 
268 	unit = DISKUNIT(dev);
269 	if ((sc = device_lookup(&ld_cd, unit))== NULL)
270 		return (ENXIO);
271 	if ((sc->sc_flags & LDF_ENABLED) == 0)
272 		return (ENODEV);
273 	part = DISKPART(dev);
274 	ldlock(sc);
275 
276 	if (sc->sc_dk.dk_openmask == 0)
277 		ldgetdisklabel(sc);
278 
279 	/* Check that the partition exists. */
280 	if (part != RAW_PART && (part >= sc->sc_dk.dk_label->d_npartitions ||
281 	    sc->sc_dk.dk_label->d_partitions[part].p_fstype == FS_UNUSED)) {
282 	     	ldunlock(sc);
283 		return (ENXIO);
284 	}
285 
286 	/* Ensure only one open at a time. */
287 	switch (fmt) {
288 	case S_IFCHR:
289 		sc->sc_dk.dk_copenmask |= (1 << part);
290 		break;
291 	case S_IFBLK:
292 		sc->sc_dk.dk_bopenmask |= (1 << part);
293 		break;
294 	}
295 	sc->sc_dk.dk_openmask =
296 	    sc->sc_dk.dk_copenmask | sc->sc_dk.dk_bopenmask;
297 
298 	ldunlock(sc);
299 	return (0);
300 }
301 
302 /* ARGSUSED */
303 int
304 ldclose(dev_t dev, int flags, int fmt, struct proc *p)
305 {
306 	struct ld_softc *sc;
307 	int part, unit;
308 
309 	unit = DISKUNIT(dev);
310 	part = DISKPART(dev);
311 	sc = device_lookup(&ld_cd, unit);
312 	ldlock(sc);
313 
314 	switch (fmt) {
315 	case S_IFCHR:
316 		sc->sc_dk.dk_copenmask &= ~(1 << part);
317 		break;
318 	case S_IFBLK:
319 		sc->sc_dk.dk_bopenmask &= ~(1 << part);
320 		break;
321 	}
322 	sc->sc_dk.dk_openmask =
323 	    sc->sc_dk.dk_copenmask | sc->sc_dk.dk_bopenmask;
324 
325 	if (sc->sc_dk.dk_openmask == 0 && sc->sc_flush != NULL)
326 		if ((*sc->sc_flush)(sc) != 0)
327 			printf("%s: unable to flush cache\n",
328 			    sc->sc_dv.dv_xname);
329 
330 	ldunlock(sc);
331 	return (0);
332 }
333 
334 /* ARGSUSED */
335 int
336 ldread(dev_t dev, struct uio *uio, int ioflag)
337 {
338 
339 	return (physio(ldstrategy, NULL, dev, B_READ, ldminphys, uio));
340 }
341 
342 /* ARGSUSED */
343 int
344 ldwrite(dev_t dev, struct uio *uio, int ioflag)
345 {
346 
347 	return (physio(ldstrategy, NULL, dev, B_WRITE, ldminphys, uio));
348 }
349 
350 /* ARGSUSED */
351 int
352 ldioctl(dev_t dev, u_long cmd, caddr_t addr, int32_t flag, struct proc *p)
353 {
354 	struct ld_softc *sc;
355 	int part, unit, error;
356 #ifdef __HAVE_OLD_DISKLABEL
357 	struct disklabel newlabel;
358 #endif
359 	struct disklabel *lp;
360 
361 	unit = DISKUNIT(dev);
362 	part = DISKPART(dev);
363 	sc = device_lookup(&ld_cd, unit);
364 	error = 0;
365 
366 	switch (cmd) {
367 	case DIOCGDINFO:
368 		memcpy(addr, sc->sc_dk.dk_label, sizeof(struct disklabel));
369 		return (0);
370 
371 #ifdef __HAVE_OLD_DISKLABEL
372 	case ODIOCGDINFO:
373 		newlabel = *(sc->sc_dk.dk_label);
374 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
375 			return ENOTTY;
376 		memcpy(addr, &newlabel, sizeof(struct olddisklabel));
377 		return (0);
378 #endif
379 
380 	case DIOCGPART:
381 		((struct partinfo *)addr)->disklab = sc->sc_dk.dk_label;
382 		((struct partinfo *)addr)->part =
383 		    &sc->sc_dk.dk_label->d_partitions[part];
384 		break;
385 
386 	case DIOCWDINFO:
387 	case DIOCSDINFO:
388 #ifdef __HAVE_OLD_DISKLABEL
389 	case ODIOCWDINFO:
390 	case ODIOCSDINFO:
391 
392 		if (cmd == ODIOCSDINFO || cmd == ODIOCWDINFO) {
393 			memset(&newlabel, 0, sizeof newlabel);
394 			memcpy(&newlabel, addr, sizeof (struct olddisklabel));
395 			lp = &newlabel;
396 		} else
397 #endif
398 		lp = (struct disklabel *)addr;
399 
400 		if ((flag & FWRITE) == 0)
401 			return (EBADF);
402 
403 		if ((error = ldlock(sc)) != 0)
404 			return (error);
405 		sc->sc_flags |= LDF_LABELLING;
406 
407 		error = setdisklabel(sc->sc_dk.dk_label,
408 		    lp, /*sc->sc_dk.dk_openmask : */0,
409 		    sc->sc_dk.dk_cpulabel);
410 		if (error == 0 && (cmd == DIOCWDINFO
411 #ifdef __HAVE_OLD_DISKLABEL
412 		    || cmd == ODIOCWDINFO
413 #endif
414 		    ))
415 			error = writedisklabel(
416 			    MAKEDISKDEV(major(dev), DISKUNIT(dev), RAW_PART),
417 			    ldstrategy, sc->sc_dk.dk_label,
418 			    sc->sc_dk.dk_cpulabel);
419 
420 		sc->sc_flags &= ~LDF_LABELLING;
421 		ldunlock(sc);
422 		break;
423 
424 	case DIOCWLABEL:
425 		if ((flag & FWRITE) == 0)
426 			return (EBADF);
427 		if (*(int *)addr)
428 			sc->sc_flags |= LDF_WLABEL;
429 		else
430 			sc->sc_flags &= ~LDF_WLABEL;
431 		break;
432 
433 	case DIOCGDEFLABEL:
434 		ldgetdefaultlabel(sc, (struct disklabel *)addr);
435 		break;
436 
437 #ifdef __HAVE_OLD_DISKLABEL
438 	case ODIOCGDEFLABEL:
439 		ldgetdefaultlabel(sc, &newlabel);
440 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
441 			return ENOTTY;
442 		memcpy(addr, &newlabel, sizeof (struct olddisklabel));
443 		break;
444 #endif
445 
446 	default:
447 		error = ENOTTY;
448 		break;
449 	}
450 
451 	return (error);
452 }
453 
454 void
455 ldstrategy(struct buf *bp)
456 {
457 	struct ld_softc *sc;
458 	int s;
459 
460 	sc = device_lookup(&ld_cd, DISKUNIT(bp->b_dev));
461 
462 	s = splbio();
463 	if (sc->sc_queuecnt >= sc->sc_maxqueuecnt) {
464 		BUFQ_PUT(&sc->sc_bufq, bp);
465 		splx(s);
466 		return;
467 	}
468 	splx(s);
469 	ldstart(sc, bp);
470 }
471 
472 static int
473 ldstart(struct ld_softc *sc, struct buf *bp)
474 {
475 	struct disklabel *lp;
476 	int part, s, rv;
477 
478 	if ((sc->sc_flags & LDF_DETACH) != 0) {
479 		bp->b_error = EIO;
480 		bp->b_flags |= B_ERROR;
481 		bp->b_resid = bp->b_bcount;
482 		biodone(bp);
483 		return (-1);
484 	}
485 
486 	part = DISKPART(bp->b_dev);
487 	lp = sc->sc_dk.dk_label;
488 
489 	/*
490 	 * The transfer must be a whole number of blocks and the offset must
491 	 * not be negative.
492 	 */
493 	if ((bp->b_bcount % lp->d_secsize) != 0 || bp->b_blkno < 0) {
494 		bp->b_flags |= B_ERROR;
495 		biodone(bp);
496 		return (-1);
497 	}
498 
499 	/*
500 	 * If it's a null transfer, return.
501 	 */
502 	if (bp->b_bcount == 0) {
503 		bp->b_resid = bp->b_bcount;
504 		biodone(bp);
505 		return (-1);
506 	}
507 
508 	/*
509 	 * Do bounds checking and adjust the transfer.  If error, process.
510 	 * If past the end of partition, just return.
511 	 */
512 	if (part != RAW_PART &&
513 	    bounds_check_with_label(bp, lp,
514 	    (sc->sc_flags & (LDF_WLABEL | LDF_LABELLING)) != 0) <= 0) {
515 		bp->b_resid = bp->b_bcount;
516 		biodone(bp);
517 		return (-1);
518 	}
519 
520 	/*
521 	 * Convert the logical block number to a physical one and put it in
522 	 * terms of the device's logical block size.
523 	 */
524 	if (lp->d_secsize >= DEV_BSIZE)
525 		bp->b_rawblkno = bp->b_blkno / (lp->d_secsize / DEV_BSIZE);
526 	else
527 		bp->b_rawblkno = bp->b_blkno * (DEV_BSIZE / lp->d_secsize);
528 
529 	if (part != RAW_PART)
530 		bp->b_rawblkno += lp->d_partitions[part].p_offset;
531 
532 	s = splbio();
533 	disk_busy(&sc->sc_dk);
534 	sc->sc_queuecnt++;
535 	splx(s);
536 
537 	if ((rv = (*sc->sc_start)(sc, bp)) != 0) {
538 		bp->b_error = rv;
539 		bp->b_flags |= B_ERROR;
540 		bp->b_resid = bp->b_bcount;
541 		s = splbio();
542 		lddone(sc, bp);
543 		splx(s);
544 	}
545 
546 	return (0);
547 }
548 
549 void
550 lddone(struct ld_softc *sc, struct buf *bp)
551 {
552 
553 	if ((bp->b_flags & B_ERROR) != 0) {
554 		diskerr(bp, "ld", "error", LOG_PRINTF, 0, sc->sc_dk.dk_label);
555 		printf("\n");
556 	}
557 
558 	disk_unbusy(&sc->sc_dk, bp->b_bcount - bp->b_resid,
559 	    (bp->b_flags & B_READ));
560 #if NRND > 0
561 	rnd_add_uint32(&sc->sc_rnd_source, bp->b_rawblkno);
562 #endif
563 	biodone(bp);
564 
565 	if (--sc->sc_queuecnt <= sc->sc_maxqueuecnt) {
566 		if ((sc->sc_flags & LDF_DRAIN) != 0)
567 			wakeup(&sc->sc_queuecnt);
568 		while ((bp = BUFQ_GET(&sc->sc_bufq)) != NULL) {
569 			if (!ldstart(sc, bp))
570 				break;
571 		}
572 	}
573 }
574 
575 int
576 ldsize(dev_t dev)
577 {
578 	struct ld_softc *sc;
579 	int part, unit, omask, size;
580 
581 	unit = DISKUNIT(dev);
582 	if ((sc = device_lookup(&ld_cd, unit)) == NULL)
583 		return (ENODEV);
584 	if ((sc->sc_flags & LDF_ENABLED) == 0)
585 		return (ENODEV);
586 	part = DISKPART(dev);
587 
588 	omask = sc->sc_dk.dk_openmask & (1 << part);
589 
590 	if (omask == 0 && ldopen(dev, 0, S_IFBLK, NULL) != 0)
591 		return (-1);
592 	else if (sc->sc_dk.dk_label->d_partitions[part].p_fstype != FS_SWAP)
593 		size = -1;
594 	else
595 		size = sc->sc_dk.dk_label->d_partitions[part].p_size *
596 		    (sc->sc_dk.dk_label->d_secsize / DEV_BSIZE);
597 	if (omask == 0 && ldclose(dev, 0, S_IFBLK, NULL) != 0)
598 		return (-1);
599 
600 	return (size);
601 }
602 
603 /*
604  * Load the label information from the specified device.
605  */
606 static void
607 ldgetdisklabel(struct ld_softc *sc)
608 {
609 	const char *errstring;
610 
611 	ldgetdefaultlabel(sc, sc->sc_dk.dk_label);
612 
613 	/* Call the generic disklabel extraction routine. */
614 	errstring = readdisklabel(MAKEDISKDEV(0, sc->sc_dv.dv_unit, RAW_PART),
615 	    ldstrategy, sc->sc_dk.dk_label, sc->sc_dk.dk_cpulabel);
616 	if (errstring != NULL)
617 		printf("%s: %s\n", sc->sc_dv.dv_xname, errstring);
618 }
619 
620 /*
621  * Construct a ficticious label.
622  */
623 static void
624 ldgetdefaultlabel(struct ld_softc *sc, struct disklabel *lp)
625 {
626 
627 	memset(lp, 0, sizeof(struct disklabel));
628 
629 	lp->d_secsize = sc->sc_secsize;
630 	lp->d_ntracks = sc->sc_nheads;
631 	lp->d_nsectors = sc->sc_nsectors;
632 	lp->d_ncylinders = sc->sc_ncylinders;
633 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
634 	lp->d_type = DTYPE_LD;
635 	strcpy(lp->d_typename, "unknown");
636 	strcpy(lp->d_packname, "fictitious");
637 	lp->d_secperunit = sc->sc_secperunit;
638 	lp->d_rpm = 7200;
639 	lp->d_interleave = 1;
640 	lp->d_flags = 0;
641 
642 	lp->d_partitions[RAW_PART].p_offset = 0;
643 	lp->d_partitions[RAW_PART].p_size =
644 	    lp->d_secperunit * (lp->d_secsize / DEV_BSIZE);
645 	lp->d_partitions[RAW_PART].p_fstype = FS_UNUSED;
646 	lp->d_npartitions = RAW_PART + 1;
647 
648 	lp->d_magic = DISKMAGIC;
649 	lp->d_magic2 = DISKMAGIC;
650 	lp->d_checksum = dkcksum(lp);
651 }
652 
653 /*
654  * Wait interruptibly for an exclusive lock.
655  *
656  * XXX Several drivers do this; it should be abstracted and made MP-safe.
657  */
658 static int
659 ldlock(struct ld_softc *sc)
660 {
661 	int error;
662 
663 	while ((sc->sc_flags & LDF_LKHELD) != 0) {
664 		sc->sc_flags |= LDF_LKWANTED;
665 		if ((error = tsleep(sc, PRIBIO | PCATCH, "ldlck", 0)) != 0)
666 			return (error);
667 	}
668 	sc->sc_flags |= LDF_LKHELD;
669 	return (0);
670 }
671 
672 /*
673  * Unlock and wake up any waiters.
674  */
675 static void
676 ldunlock(struct ld_softc *sc)
677 {
678 
679 	sc->sc_flags &= ~LDF_LKHELD;
680 	if ((sc->sc_flags & LDF_LKWANTED) != 0) {
681 		sc->sc_flags &= ~LDF_LKWANTED;
682 		wakeup(sc);
683 	}
684 }
685 
686 /*
687  * Take a dump.
688  */
689 int
690 lddump(dev_t dev, daddr_t blkno, caddr_t va, size_t size)
691 {
692 	struct ld_softc *sc;
693 	struct disklabel *lp;
694 	int unit, part, nsects, sectoff, towrt, nblk, maxblkcnt, rv;
695 	static int dumping;
696 
697 	unit = DISKUNIT(dev);
698 	if ((sc = device_lookup(&ld_cd, unit)) == NULL)
699 		return (ENXIO);
700 	if ((sc->sc_flags & LDF_ENABLED) == 0)
701 		return (ENODEV);
702 	if (sc->sc_dump == NULL)
703 		return (ENXIO);
704 
705 	/* Check if recursive dump; if so, punt. */
706 	if (dumping)
707 		return (EFAULT);
708 	dumping = 1;
709 
710 	/* Convert to disk sectors.  Request must be a multiple of size. */
711 	part = DISKPART(dev);
712 	lp = sc->sc_dk.dk_label;
713 	if ((size % lp->d_secsize) != 0)
714 		return (EFAULT);
715 	towrt = size / lp->d_secsize;
716 	blkno = dbtob(blkno) / lp->d_secsize;	/* blkno in DEV_BSIZE units */
717 
718 	nsects = lp->d_partitions[part].p_size;
719 	sectoff = lp->d_partitions[part].p_offset;
720 
721 	/* Check transfer bounds against partition size. */
722 	if ((blkno < 0) || ((blkno + towrt) > nsects))
723 		return (EINVAL);
724 
725 	/* Offset block number to start of partition. */
726 	blkno += sectoff;
727 
728 	/* Start dumping and return when done. */
729 	maxblkcnt = sc->sc_maxxfer / sc->sc_secsize - 1;
730 	while (towrt > 0) {
731 		nblk = min(maxblkcnt, towrt);
732 
733 		if ((rv = (*sc->sc_dump)(sc, va, blkno, nblk)) != 0)
734 			return (rv);
735 
736 		towrt -= nblk;
737 		blkno += nblk;
738 		va += nblk * sc->sc_secsize;
739 	}
740 
741 	dumping = 0;
742 	return (0);
743 }
744 
745 /*
746  * Adjust the size of a transfer.
747  */
748 static void
749 ldminphys(struct buf *bp)
750 {
751 	struct ld_softc *sc;
752 
753 	sc = device_lookup(&ld_cd, DISKUNIT(bp->b_dev));
754 
755 	if (bp->b_bcount > sc->sc_maxxfer)
756 		bp->b_bcount = sc->sc_maxxfer;
757 	minphys(bp);
758 }
759