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ld.c revision 1.18
      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