xref: /netbsd-src/sys/dev/dksubr.c (revision 8ecbf5f02b752fcb7debe1a8fab1dc82602bc760)
1 /* $NetBSD: dksubr.c,v 1.112 2020/03/01 03:21:54 riastradh Exp $ */
2 
3 /*-
4  * Copyright (c) 1996, 1997, 1998, 1999, 2002, 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe and Roland C. Dowdeswell.
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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: dksubr.c,v 1.112 2020/03/01 03:21:54 riastradh Exp $");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/stat.h>
38 #include <sys/proc.h>
39 #include <sys/ioctl.h>
40 #include <sys/device.h>
41 #include <sys/disk.h>
42 #include <sys/disklabel.h>
43 #include <sys/buf.h>
44 #include <sys/bufq.h>
45 #include <sys/vnode.h>
46 #include <sys/fcntl.h>
47 #include <sys/namei.h>
48 #include <sys/module.h>
49 #include <sys/syslog.h>
50 
51 #include <dev/dkvar.h>
52 #include <miscfs/specfs/specdev.h> /* for v_rdev */
53 
54 int	dkdebug = 0;
55 
56 #ifdef DEBUG
57 #define DKDB_FOLLOW	0x1
58 #define DKDB_INIT	0x2
59 #define DKDB_VNODE	0x4
60 #define DKDB_DUMP	0x8
61 
62 #define IFDEBUG(x,y)		if (dkdebug & (x)) y
63 #define DPRINTF(x,y)		IFDEBUG(x, printf y)
64 #define DPRINTF_FOLLOW(y)	DPRINTF(DKDB_FOLLOW, y)
65 #else
66 #define IFDEBUG(x,y)
67 #define DPRINTF(x,y)
68 #define DPRINTF_FOLLOW(y)
69 #endif
70 
71 #define DKF_READYFORDUMP	(DKF_INITED|DKF_TAKEDUMP)
72 
73 static int dk_subr_modcmd(modcmd_t, void *);
74 
75 #define DKLABELDEV(dev)	\
76 	(MAKEDISKDEV(major((dev)), DISKUNIT((dev)), RAW_PART))
77 
78 static void	dk_makedisklabel(struct dk_softc *);
79 static int	dk_translate(struct dk_softc *, struct buf *);
80 static void	dk_done1(struct dk_softc *, struct buf *, bool);
81 
82 void
83 dk_init(struct dk_softc *dksc, device_t dev, int dtype)
84 {
85 
86 	memset(dksc, 0x0, sizeof(*dksc));
87 	dksc->sc_dtype = dtype;
88 	dksc->sc_dev = dev;
89 
90 	strlcpy(dksc->sc_xname, device_xname(dev), DK_XNAME_SIZE);
91 	dksc->sc_dkdev.dk_name = dksc->sc_xname;
92 }
93 
94 void
95 dk_attach(struct dk_softc *dksc)
96 {
97 	KASSERT(dksc->sc_dev != NULL);
98 
99 	mutex_init(&dksc->sc_iolock, MUTEX_DEFAULT, IPL_VM);
100 	dksc->sc_flags |= DKF_READYFORDUMP;
101 #ifdef DIAGNOSTIC
102 	dksc->sc_flags |= DKF_WARNLABEL | DKF_LABELSANITY;
103 #endif
104 
105 	if ((dksc->sc_flags & DKF_NO_RND) == 0) {
106 		/* Attach the device into the rnd source list. */
107 		rnd_attach_source(&dksc->sc_rnd_source, dksc->sc_xname,
108 		    RND_TYPE_DISK, RND_FLAG_DEFAULT);
109 	}
110 }
111 
112 void
113 dk_detach(struct dk_softc *dksc)
114 {
115 	if ((dksc->sc_flags & DKF_NO_RND) == 0) {
116 		/* Unhook the entropy source. */
117 		rnd_detach_source(&dksc->sc_rnd_source);
118 	}
119 
120 	dksc->sc_flags &= ~DKF_READYFORDUMP;
121 	mutex_destroy(&dksc->sc_iolock);
122 }
123 
124 /* ARGSUSED */
125 int
126 dk_open(struct dk_softc *dksc, dev_t dev,
127     int flags, int fmt, struct lwp *l)
128 {
129 	const struct dkdriver *dkd = dksc->sc_dkdev.dk_driver;
130 	struct	disklabel *lp = dksc->sc_dkdev.dk_label;
131 	int	part = DISKPART(dev);
132 	int	pmask = 1 << part;
133 	int	ret = 0;
134 	struct disk *dk = &dksc->sc_dkdev;
135 
136 	DPRINTF_FOLLOW(("%s(%s, %p, 0x%"PRIx64", 0x%x)\n", __func__,
137 	    dksc->sc_xname, dksc, dev, flags));
138 
139 	mutex_enter(&dk->dk_openlock);
140 
141 	/*
142 	 * If there are wedges, and this is not RAW_PART, then we
143 	 * need to fail.
144 	 */
145 	if (dk->dk_nwedges != 0 && part != RAW_PART) {
146 		ret = EBUSY;
147 		goto done;
148 	}
149 
150 	/* If no dkdriver attached, bail */
151 	if (dkd == NULL) {
152 		ret = ENXIO;
153 		goto done;
154 	}
155 
156 	/*
157 	 * initialize driver for the first opener
158 	 */
159 	if (dk->dk_openmask == 0 && dkd->d_firstopen != NULL) {
160 		ret = (*dkd->d_firstopen)(dksc->sc_dev, dev, flags, fmt);
161 		if (ret)
162 			goto done;
163 	}
164 
165 	/*
166 	 * If we're init'ed and there are no other open partitions then
167 	 * update the in-core disklabel.
168 	 */
169 	if ((dksc->sc_flags & DKF_INITED)) {
170 		if ((dksc->sc_flags & DKF_VLABEL) == 0) {
171 			dksc->sc_flags |= DKF_VLABEL;
172 			dk_getdisklabel(dksc, dev);
173 		}
174 	}
175 
176 	/* Fail if we can't find the partition. */
177 	if (part != RAW_PART &&
178 	    ((dksc->sc_flags & DKF_VLABEL) == 0 ||
179 	     part >= lp->d_npartitions ||
180 	     lp->d_partitions[part].p_fstype == FS_UNUSED)) {
181 		ret = ENXIO;
182 		goto done;
183 	}
184 
185 	/* Mark our unit as open. */
186 	switch (fmt) {
187 	case S_IFCHR:
188 		dk->dk_copenmask |= pmask;
189 		break;
190 	case S_IFBLK:
191 		dk->dk_bopenmask |= pmask;
192 		break;
193 	}
194 
195 	dk->dk_openmask = dk->dk_copenmask | dk->dk_bopenmask;
196 
197 done:
198 	mutex_exit(&dk->dk_openlock);
199 	return ret;
200 }
201 
202 /* ARGSUSED */
203 int
204 dk_close(struct dk_softc *dksc, dev_t dev,
205     int flags, int fmt, struct lwp *l)
206 {
207 	const struct dkdriver *dkd = dksc->sc_dkdev.dk_driver;
208 	int	part = DISKPART(dev);
209 	int	pmask = 1 << part;
210 	struct disk *dk = &dksc->sc_dkdev;
211 
212 	DPRINTF_FOLLOW(("%s(%s, %p, 0x%"PRIx64", 0x%x)\n", __func__,
213 	    dksc->sc_xname, dksc, dev, flags));
214 
215 	mutex_enter(&dk->dk_openlock);
216 
217 	switch (fmt) {
218 	case S_IFCHR:
219 		dk->dk_copenmask &= ~pmask;
220 		break;
221 	case S_IFBLK:
222 		dk->dk_bopenmask &= ~pmask;
223 		break;
224 	}
225 	dk->dk_openmask = dk->dk_copenmask | dk->dk_bopenmask;
226 
227 	if (dk->dk_openmask == 0) {
228 		if (dkd->d_lastclose != NULL)
229 			(*dkd->d_lastclose)(dksc->sc_dev);
230 		if ((dksc->sc_flags & DKF_KLABEL) == 0)
231 			dksc->sc_flags &= ~DKF_VLABEL;
232 	}
233 
234 	mutex_exit(&dk->dk_openlock);
235 	return 0;
236 }
237 
238 static int
239 dk_translate(struct dk_softc *dksc, struct buf *bp)
240 {
241 	int	part;
242 	int	wlabel;
243 	daddr_t	blkno;
244 	struct disklabel *lp;
245 	struct disk *dk;
246 	uint64_t numsecs;
247 	unsigned secsize;
248 
249 	lp = dksc->sc_dkdev.dk_label;
250 	dk = &dksc->sc_dkdev;
251 
252 	part = DISKPART(bp->b_dev);
253 	numsecs = dk->dk_geom.dg_secperunit;
254 	secsize = dk->dk_geom.dg_secsize;
255 
256 	/*
257 	 * The transfer must be a whole number of blocks and the offset must
258 	 * not be negative.
259 	 */
260 	if ((bp->b_bcount % secsize) != 0 || bp->b_blkno < 0) {
261 		bp->b_error = EINVAL;
262 		goto done;
263 	}
264 
265 	/* If there is nothing to do, then we are done */
266 	if (bp->b_bcount == 0)
267 		goto done;
268 
269 	wlabel = dksc->sc_flags & (DKF_WLABEL|DKF_LABELLING);
270 	if (part == RAW_PART) {
271 		uint64_t numblocks = btodb(numsecs * secsize);
272 		if (bounds_check_with_mediasize(bp, DEV_BSIZE, numblocks) <= 0)
273 			goto done;
274 	} else {
275 		if (bounds_check_with_label(&dksc->sc_dkdev, bp, wlabel) <= 0)
276 			goto done;
277 	}
278 
279 	/*
280 	 * Convert the block number to absolute and put it in terms
281 	 * of the device's logical block size.
282 	 */
283 	if (secsize >= DEV_BSIZE)
284 		blkno = bp->b_blkno / (secsize / DEV_BSIZE);
285 	else
286 		blkno = bp->b_blkno * (DEV_BSIZE / secsize);
287 
288 	if (part != RAW_PART)
289 		blkno += lp->d_partitions[DISKPART(bp->b_dev)].p_offset;
290 	bp->b_rawblkno = blkno;
291 
292 	return -1;
293 
294 done:
295 	bp->b_resid = bp->b_bcount;
296 	return bp->b_error;
297 }
298 
299 static int
300 dk_strategy1(struct dk_softc *dksc, struct buf *bp)
301 {
302 	int error;
303 
304 	DPRINTF_FOLLOW(("%s(%s, %p, %p)\n", __func__,
305 	    dksc->sc_xname, dksc, bp));
306 
307 	if (!(dksc->sc_flags & DKF_INITED)) {
308 		DPRINTF_FOLLOW(("%s: not inited\n", __func__));
309 		bp->b_error = ENXIO;
310 		bp->b_resid = bp->b_bcount;
311 		biodone(bp);
312 		return 1;
313 	}
314 
315 	error = dk_translate(dksc, bp);
316 	if (error >= 0) {
317 		biodone(bp);
318 		return 1;
319 	}
320 
321 	return 0;
322 }
323 
324 void
325 dk_strategy(struct dk_softc *dksc, struct buf *bp)
326 {
327 	int error;
328 
329 	error = dk_strategy1(dksc, bp);
330 	if (error)
331 		return;
332 
333 	/*
334 	 * Queue buffer and start unit
335 	 */
336 	dk_start(dksc, bp);
337 }
338 
339 int
340 dk_strategy_defer(struct dk_softc *dksc, struct buf *bp)
341 {
342 	int error;
343 
344 	error = dk_strategy1(dksc, bp);
345 	if (error)
346 		return error;
347 
348 	/*
349 	 * Queue buffer only
350 	 */
351 	mutex_enter(&dksc->sc_iolock);
352 	disk_wait(&dksc->sc_dkdev);
353 	bufq_put(dksc->sc_bufq, bp);
354 	mutex_exit(&dksc->sc_iolock);
355 
356 	return 0;
357 }
358 
359 int
360 dk_strategy_pending(struct dk_softc *dksc)
361 {
362 	struct buf *bp;
363 
364 	if (!(dksc->sc_flags & DKF_INITED)) {
365 		DPRINTF_FOLLOW(("%s: not inited\n", __func__));
366 		return 0;
367 	}
368 
369 	mutex_enter(&dksc->sc_iolock);
370 	bp = bufq_peek(dksc->sc_bufq);
371 	mutex_exit(&dksc->sc_iolock);
372 
373 	return bp != NULL;
374 }
375 
376 void
377 dk_start(struct dk_softc *dksc, struct buf *bp)
378 {
379 	const struct dkdriver *dkd = dksc->sc_dkdev.dk_driver;
380 	int error;
381 
382 	if (!(dksc->sc_flags & DKF_INITED)) {
383 		DPRINTF_FOLLOW(("%s: not inited\n", __func__));
384 		return;
385 	}
386 
387 	mutex_enter(&dksc->sc_iolock);
388 
389 	if (bp != NULL) {
390 		bp->b_ci = curcpu();
391 		disk_wait(&dksc->sc_dkdev);
392 		bufq_put(dksc->sc_bufq, bp);
393 	}
394 
395 	/*
396 	 * If another thread is running the queue, increment
397 	 * busy counter to 2 so that the queue is retried,
398 	 * because the driver may now accept additional
399 	 * requests.
400 	 */
401 	if (dksc->sc_busy < 2)
402 		dksc->sc_busy++;
403 	if (dksc->sc_busy > 1)
404 		goto done;
405 
406 	/*
407 	 * Peeking at the buffer queue and committing the operation
408 	 * only after success isn't atomic.
409 	 *
410 	 * So when a diskstart fails, the buffer is saved
411 	 * and tried again before the next buffer is fetched.
412 	 * dk_drain() handles flushing of a saved buffer.
413 	 *
414 	 * This keeps order of I/O operations, unlike bufq_put.
415 	 */
416 
417 	while (dksc->sc_busy > 0) {
418 
419 		bp = dksc->sc_deferred;
420 		dksc->sc_deferred = NULL;
421 
422 		if (bp == NULL)
423 			bp = bufq_get(dksc->sc_bufq);
424 
425 		while (bp != NULL) {
426 
427 			disk_busy(&dksc->sc_dkdev);
428 			mutex_exit(&dksc->sc_iolock);
429 			error = dkd->d_diskstart(dksc->sc_dev, bp);
430 			mutex_enter(&dksc->sc_iolock);
431 			if (error == EAGAIN) {
432 				KASSERT(dksc->sc_deferred == NULL);
433 				dksc->sc_deferred = bp;
434 				disk_unbusy(&dksc->sc_dkdev, 0, (bp->b_flags & B_READ));
435 				disk_wait(&dksc->sc_dkdev);
436 				break;
437 			}
438 
439 			if (error != 0) {
440 				bp->b_error = error;
441 				bp->b_resid = bp->b_bcount;
442 				dk_done1(dksc, bp, false);
443 			}
444 
445 			bp = bufq_get(dksc->sc_bufq);
446 		}
447 
448 		dksc->sc_busy--;
449 	}
450 done:
451 	mutex_exit(&dksc->sc_iolock);
452 }
453 
454 static void
455 dk_done1(struct dk_softc *dksc, struct buf *bp, bool lock)
456 {
457 	struct disk *dk = &dksc->sc_dkdev;
458 
459 	if (bp->b_error != 0) {
460 		struct cfdriver *cd = device_cfdriver(dksc->sc_dev);
461 
462 		diskerr(bp, cd->cd_name, "error", LOG_PRINTF, 0,
463 			dk->dk_label);
464 		printf("\n");
465 	}
466 
467 	if (lock)
468 		mutex_enter(&dksc->sc_iolock);
469 	disk_unbusy(dk, bp->b_bcount - bp->b_resid, (bp->b_flags & B_READ));
470 
471 	if ((dksc->sc_flags & DKF_NO_RND) == 0)
472 		rnd_add_uint32(&dksc->sc_rnd_source, bp->b_rawblkno);
473 	if (lock)
474 		mutex_exit(&dksc->sc_iolock);
475 
476 	biodone(bp);
477 }
478 
479 void
480 dk_done(struct dk_softc *dksc, struct buf *bp)
481 {
482 	dk_done1(dksc, bp, true);
483 }
484 
485 void
486 dk_drain(struct dk_softc *dksc)
487 {
488 	struct buf *bp;
489 
490 	mutex_enter(&dksc->sc_iolock);
491 	bp = dksc->sc_deferred;
492 	dksc->sc_deferred = NULL;
493 	if (bp != NULL) {
494 		bp->b_error = EIO;
495 		bp->b_resid = bp->b_bcount;
496 		biodone(bp);
497 	}
498 	bufq_drain(dksc->sc_bufq);
499 	mutex_exit(&dksc->sc_iolock);
500 }
501 
502 int
503 dk_discard(struct dk_softc *dksc, dev_t dev, off_t pos, off_t len)
504 {
505 	const struct dkdriver *dkd = dksc->sc_dkdev.dk_driver;
506 	unsigned secsize = dksc->sc_dkdev.dk_geom.dg_secsize;
507 	struct buf tmp, *bp = &tmp;
508 	int maxsz;
509 	int error = 0;
510 
511 	KASSERT(len >= 0);
512 
513 	DPRINTF_FOLLOW(("%s(%s, %p, 0x"PRIx64", %jd, %jd)\n", __func__,
514 	    dksc->sc_xname, dksc, (intmax_t)pos, (intmax_t)len));
515 
516 	if (!(dksc->sc_flags & DKF_INITED)) {
517 		DPRINTF_FOLLOW(("%s: not inited\n", __func__));
518 		return ENXIO;
519 	}
520 
521 	if (secsize == 0 || (pos % secsize) != 0 || (len % secsize) != 0)
522 		return EINVAL;
523 
524 	/* largest value that b_bcount can store */
525 	maxsz = rounddown(INT_MAX, secsize);
526 
527 	while (len > 0) {
528 		/* enough data to please the bounds checking code */
529 		bp->b_dev = dev;
530 		bp->b_blkno = (daddr_t)(pos / secsize);
531 		bp->b_bcount = uimin(len, maxsz);
532 		bp->b_flags = B_WRITE;
533 
534 		error = dk_translate(dksc, bp);
535 		if (error >= 0)
536 			break;
537 
538 		error = dkd->d_discard(dksc->sc_dev,
539 			(off_t)bp->b_rawblkno * secsize,
540 			(off_t)bp->b_bcount);
541 		if (error)
542 			break;
543 
544 		pos += bp->b_bcount;
545 		len -= bp->b_bcount;
546 	}
547 
548 	return error;
549 }
550 
551 int
552 dk_size(struct dk_softc *dksc, dev_t dev)
553 {
554 	const struct dkdriver *dkd = dksc->sc_dkdev.dk_driver;
555 	struct	disklabel *lp;
556 	int	is_open;
557 	int	part;
558 	int	size;
559 
560 	if ((dksc->sc_flags & DKF_INITED) == 0)
561 		return -1;
562 
563 	part = DISKPART(dev);
564 	is_open = dksc->sc_dkdev.dk_openmask & (1 << part);
565 
566 	if (!is_open && dkd->d_open(dev, 0, S_IFBLK, curlwp))
567 		return -1;
568 
569 	lp = dksc->sc_dkdev.dk_label;
570 	if (lp->d_partitions[part].p_fstype != FS_SWAP)
571 		size = -1;
572 	else
573 		size = lp->d_partitions[part].p_size *
574 		    (lp->d_secsize / DEV_BSIZE);
575 
576 	if (!is_open && dkd->d_close(dev, 0, S_IFBLK, curlwp))
577 		return -1;
578 
579 	return size;
580 }
581 
582 int
583 dk_ioctl(struct dk_softc *dksc, dev_t dev,
584 	    u_long cmd, void *data, int flag, struct lwp *l)
585 {
586 	const struct dkdriver *dkd = dksc->sc_dkdev.dk_driver;
587 	struct	disklabel *lp;
588 	struct	disk *dk = &dksc->sc_dkdev;
589 #ifdef __HAVE_OLD_DISKLABEL
590 	struct	disklabel newlabel;
591 #endif
592 	int	error;
593 
594 	DPRINTF_FOLLOW(("%s(%s, %p, 0x%"PRIx64", 0x%lx)\n", __func__,
595 	    dksc->sc_xname, dksc, dev, cmd));
596 
597 	/* ensure that the pseudo disk is open for writes for these commands */
598 	switch (cmd) {
599 	case DIOCSDINFO:
600 	case DIOCWDINFO:
601 #ifdef __HAVE_OLD_DISKLABEL
602 	case ODIOCSDINFO:
603 	case ODIOCWDINFO:
604 #endif
605 	case DIOCKLABEL:
606 	case DIOCWLABEL:
607 	case DIOCAWEDGE:
608 	case DIOCDWEDGE:
609 	case DIOCSSTRATEGY:
610 		if ((flag & FWRITE) == 0)
611 			return EBADF;
612 	}
613 
614 	/* ensure that the pseudo-disk is initialized for these */
615 	switch (cmd) {
616 	case DIOCGDINFO:
617 	case DIOCSDINFO:
618 	case DIOCWDINFO:
619 	case DIOCGPARTINFO:
620 	case DIOCKLABEL:
621 	case DIOCWLABEL:
622 	case DIOCGDEFLABEL:
623 	case DIOCAWEDGE:
624 	case DIOCDWEDGE:
625 	case DIOCLWEDGES:
626 	case DIOCMWEDGES:
627 	case DIOCRMWEDGES:
628 	case DIOCCACHESYNC:
629 #ifdef __HAVE_OLD_DISKLABEL
630 	case ODIOCGDINFO:
631 	case ODIOCSDINFO:
632 	case ODIOCWDINFO:
633 	case ODIOCGDEFLABEL:
634 #endif
635 		if ((dksc->sc_flags & DKF_INITED) == 0)
636 			return ENXIO;
637 	}
638 
639 	error = disk_ioctl(dk, dev, cmd, data, flag, l);
640 	if (error != EPASSTHROUGH)
641 		return error;
642 	else
643 		error = 0;
644 
645 	switch (cmd) {
646 	case DIOCWDINFO:
647 	case DIOCSDINFO:
648 #ifdef __HAVE_OLD_DISKLABEL
649 	case ODIOCWDINFO:
650 	case ODIOCSDINFO:
651 #endif
652 #ifdef __HAVE_OLD_DISKLABEL
653 		if (cmd == ODIOCSDINFO || cmd == ODIOCWDINFO) {
654 			memset(&newlabel, 0, sizeof newlabel);
655 			memcpy(&newlabel, data, sizeof (struct olddisklabel));
656 			lp = &newlabel;
657 		} else
658 #endif
659 		lp = (struct disklabel *)data;
660 
661 		mutex_enter(&dk->dk_openlock);
662 		dksc->sc_flags |= DKF_LABELLING;
663 
664 		error = setdisklabel(dksc->sc_dkdev.dk_label,
665 		    lp, 0, dksc->sc_dkdev.dk_cpulabel);
666 		if (error == 0) {
667 			if (cmd == DIOCWDINFO
668 #ifdef __HAVE_OLD_DISKLABEL
669 			    || cmd == ODIOCWDINFO
670 #endif
671 			   )
672 				error = writedisklabel(DKLABELDEV(dev),
673 				    dkd->d_strategy, dksc->sc_dkdev.dk_label,
674 				    dksc->sc_dkdev.dk_cpulabel);
675 		}
676 
677 		dksc->sc_flags &= ~DKF_LABELLING;
678 		mutex_exit(&dk->dk_openlock);
679 		break;
680 
681 	case DIOCKLABEL:
682 		if (*(int *)data != 0)
683 			dksc->sc_flags |= DKF_KLABEL;
684 		else
685 			dksc->sc_flags &= ~DKF_KLABEL;
686 		break;
687 
688 	case DIOCWLABEL:
689 		if (*(int *)data != 0)
690 			dksc->sc_flags |= DKF_WLABEL;
691 		else
692 			dksc->sc_flags &= ~DKF_WLABEL;
693 		break;
694 
695 	case DIOCGDEFLABEL:
696 		dk_getdefaultlabel(dksc, (struct disklabel *)data);
697 		break;
698 
699 #ifdef __HAVE_OLD_DISKLABEL
700 	case ODIOCGDEFLABEL:
701 		dk_getdefaultlabel(dksc, &newlabel);
702 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
703 			return ENOTTY;
704 		memcpy(data, &newlabel, sizeof (struct olddisklabel));
705 		break;
706 #endif
707 
708 	case DIOCGSTRATEGY:
709 	    {
710 		struct disk_strategy *dks = (void *)data;
711 
712 		mutex_enter(&dksc->sc_iolock);
713 		if (dksc->sc_bufq != NULL)
714 			strlcpy(dks->dks_name,
715 			    bufq_getstrategyname(dksc->sc_bufq),
716 			    sizeof(dks->dks_name));
717 		else
718 			error = EINVAL;
719 		mutex_exit(&dksc->sc_iolock);
720 		dks->dks_paramlen = 0;
721 		break;
722 	    }
723 
724 	case DIOCSSTRATEGY:
725 	    {
726 		struct disk_strategy *dks = (void *)data;
727 		struct bufq_state *new;
728 		struct bufq_state *old;
729 
730 		if (dks->dks_param != NULL) {
731 			return EINVAL;
732 		}
733 		dks->dks_name[sizeof(dks->dks_name) - 1] = 0; /* ensure term */
734 		error = bufq_alloc(&new, dks->dks_name,
735 		    BUFQ_EXACT|BUFQ_SORT_RAWBLOCK);
736 		if (error) {
737 			return error;
738 		}
739 		mutex_enter(&dksc->sc_iolock);
740 		old = dksc->sc_bufq;
741 		if (old)
742 			bufq_move(new, old);
743 		dksc->sc_bufq = new;
744 		mutex_exit(&dksc->sc_iolock);
745 		if (old)
746 			bufq_free(old);
747 		break;
748 	    }
749 
750 	default:
751 		error = ENOTTY;
752 	}
753 
754 	return error;
755 }
756 
757 /*
758  * dk_dump dumps all of physical memory into the partition specified.
759  * This requires substantially more framework than {s,w}ddump, and hence
760  * is probably much more fragile.
761  *
762  */
763 
764 #define DKFF_READYFORDUMP(x)	(((x) & DKF_READYFORDUMP) == DKF_READYFORDUMP)
765 static volatile int	dk_dumping = 0;
766 
767 /* ARGSUSED */
768 int
769 dk_dump(struct dk_softc *dksc, dev_t dev,
770     daddr_t blkno, void *vav, size_t size, int flags)
771 {
772 	const struct dkdriver *dkd = dksc->sc_dkdev.dk_driver;
773 	struct disk_geom *dg = &dksc->sc_dkdev.dk_geom;
774 	char *va = vav;
775 	struct disklabel *lp;
776 	struct partition *p;
777 	int part, towrt, maxblkcnt, nblk;
778 	int maxxfer, rv = 0;
779 
780 	/*
781 	 * ensure that we consider this device to be safe for dumping,
782 	 * and that the device is configured.
783 	 */
784 	if (!DKFF_READYFORDUMP(dksc->sc_flags)) {
785 		DPRINTF(DKDB_DUMP, ("%s: bad dump flags 0x%x\n", __func__,
786 		    dksc->sc_flags));
787 		return ENXIO;
788 	}
789 
790 	/* ensure that we are not already dumping */
791 	if (dk_dumping)
792 		return EFAULT;
793 	if ((flags & DK_DUMP_RECURSIVE) == 0)
794 		dk_dumping = 1;
795 
796 	if (dkd->d_dumpblocks == NULL) {
797 		DPRINTF(DKDB_DUMP, ("%s: no dumpblocks\n", __func__));
798 		return ENXIO;
799 	}
800 
801 	/* device specific max transfer size */
802 	maxxfer = MAXPHYS;
803 	if (dkd->d_iosize != NULL)
804 		(*dkd->d_iosize)(dksc->sc_dev, &maxxfer);
805 
806 	/* Convert to disk sectors.  Request must be a multiple of size. */
807 	part = DISKPART(dev);
808 	lp = dksc->sc_dkdev.dk_label;
809 	if ((size % lp->d_secsize) != 0) {
810 		DPRINTF(DKDB_DUMP, ("%s: odd size %zu\n", __func__, size));
811 		return EFAULT;
812 	}
813 	towrt = size / lp->d_secsize;
814 	blkno = dbtob(blkno) / lp->d_secsize;   /* blkno in secsize units */
815 
816 	p = &lp->d_partitions[part];
817 	if (part == RAW_PART) {
818 		if (p->p_fstype != FS_UNUSED) {
819 			DPRINTF(DKDB_DUMP, ("%s: bad fstype %d\n", __func__,
820 			    p->p_fstype));
821 			return ENXIO;
822 		}
823 		/* Check whether dump goes to a wedge */
824 		if (dksc->sc_dkdev.dk_nwedges == 0) {
825 			DPRINTF(DKDB_DUMP, ("%s: dump to raw\n", __func__));
826 			return ENXIO;
827 		}
828 		/* Check transfer bounds against media size */
829 		if (blkno < 0 || (blkno + towrt) > dg->dg_secperunit) {
830 			DPRINTF(DKDB_DUMP, ("%s: out of bounds blkno=%jd, towrt=%d, "
831 			    "nsects=%jd\n", __func__, (intmax_t)blkno, towrt, dg->dg_secperunit));
832 			return EINVAL;
833 		}
834 	} else {
835 		int nsects, sectoff;
836 
837 		if (p->p_fstype != FS_SWAP) {
838 			DPRINTF(DKDB_DUMP, ("%s: bad fstype %d\n", __func__,
839 			    p->p_fstype));
840 			return ENXIO;
841 		}
842 		nsects = p->p_size;
843 		sectoff = p->p_offset;
844 
845 		/* Check transfer bounds against partition size. */
846 		if ((blkno < 0) || ((blkno + towrt) > nsects)) {
847 			DPRINTF(DKDB_DUMP, ("%s: out of bounds blkno=%jd, towrt=%d, "
848 			    "nsects=%d\n", __func__, (intmax_t)blkno, towrt, nsects));
849 			return EINVAL;
850 		}
851 
852 		/* Offset block number to start of partition. */
853 		blkno += sectoff;
854 	}
855 
856 	/* Start dumping and return when done. */
857 	maxblkcnt = howmany(maxxfer, lp->d_secsize);
858 	while (towrt > 0) {
859 		nblk = uimin(maxblkcnt, towrt);
860 
861 		if ((rv = (*dkd->d_dumpblocks)(dksc->sc_dev, va, blkno, nblk))
862 		    != 0) {
863 			DPRINTF(DKDB_DUMP, ("%s: dumpblocks %d\n", __func__,
864 			    rv));
865 			return rv;
866 		}
867 
868 		towrt -= nblk;
869 		blkno += nblk;
870 		va += nblk * lp->d_secsize;
871 	}
872 
873 	if ((flags & DK_DUMP_RECURSIVE) == 0)
874 		dk_dumping = 0;
875 
876 	return 0;
877 }
878 
879 /* ARGSUSED */
880 void
881 dk_getdefaultlabel(struct dk_softc *dksc, struct disklabel *lp)
882 {
883 	const struct dkdriver *dkd = dksc->sc_dkdev.dk_driver;
884 	struct disk_geom *dg = &dksc->sc_dkdev.dk_geom;
885 
886 	memset(lp, 0, sizeof(*lp));
887 
888 	if (dg->dg_secperunit > UINT32_MAX)
889 		lp->d_secperunit = UINT32_MAX;
890 	else
891 		lp->d_secperunit = dg->dg_secperunit;
892 	lp->d_secsize = dg->dg_secsize;
893 	lp->d_nsectors = dg->dg_nsectors;
894 	lp->d_ntracks = dg->dg_ntracks;
895 	lp->d_ncylinders = dg->dg_ncylinders;
896 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
897 
898 	strlcpy(lp->d_typename, dksc->sc_xname, sizeof(lp->d_typename));
899 	lp->d_type = dksc->sc_dtype;
900 	strlcpy(lp->d_packname, "fictitious", sizeof(lp->d_packname));
901 	lp->d_rpm = 3600;
902 	lp->d_interleave = 1;
903 	lp->d_flags = 0;
904 
905 	lp->d_partitions[RAW_PART].p_offset = 0;
906 	lp->d_partitions[RAW_PART].p_size = lp->d_secperunit;
907 	lp->d_partitions[RAW_PART].p_fstype = FS_UNUSED;
908 	lp->d_npartitions = RAW_PART + 1;
909 
910 	lp->d_magic = DISKMAGIC;
911 	lp->d_magic2 = DISKMAGIC;
912 
913 	if (dkd->d_label)
914 		dkd->d_label(dksc->sc_dev, lp);
915 
916 	lp->d_checksum = dkcksum(lp);
917 }
918 
919 /* ARGSUSED */
920 void
921 dk_getdisklabel(struct dk_softc *dksc, dev_t dev)
922 {
923 	const struct dkdriver *dkd = dksc->sc_dkdev.dk_driver;
924 	struct	 disklabel *lp = dksc->sc_dkdev.dk_label;
925 	struct	 cpu_disklabel *clp = dksc->sc_dkdev.dk_cpulabel;
926 	struct   disk_geom *dg = &dksc->sc_dkdev.dk_geom;
927 	struct	 partition *pp;
928 	int	 i, lpratio, dgratio;
929 	const char	*errstring;
930 
931 	memset(clp, 0x0, sizeof(*clp));
932 	dk_getdefaultlabel(dksc, lp);
933 	errstring = readdisklabel(DKLABELDEV(dev), dkd->d_strategy,
934 	    dksc->sc_dkdev.dk_label, dksc->sc_dkdev.dk_cpulabel);
935 	if (errstring) {
936 		dk_makedisklabel(dksc);
937 		if (dksc->sc_flags & DKF_WARNLABEL)
938 			printf("%s: %s\n", dksc->sc_xname, errstring);
939 		return;
940 	}
941 
942 	if ((dksc->sc_flags & DKF_LABELSANITY) == 0)
943 		return;
944 
945 	/* Convert sector counts to multiple of DEV_BSIZE for comparison */
946 	lpratio = dgratio = 1;
947 	if (lp->d_secsize > DEV_BSIZE)
948 		lpratio = lp->d_secsize / DEV_BSIZE;
949 	if (dg->dg_secsize > DEV_BSIZE)
950 		dgratio = dg->dg_secsize / DEV_BSIZE;
951 
952 	/* Sanity check */
953 	if ((uint64_t)lp->d_secperunit * lpratio > dg->dg_secperunit * dgratio)
954 		printf("WARNING: %s: "
955 		    "total unit size in disklabel (%" PRIu64 ") "
956 		    "!= the size of %s (%" PRIu64 ")\n", dksc->sc_xname,
957 		    (uint64_t)lp->d_secperunit * lpratio, dksc->sc_xname,
958 		    dg->dg_secperunit * dgratio);
959 	else if (lp->d_secperunit < UINT32_MAX &&
960 	    (uint64_t)lp->d_secperunit * lpratio < dg->dg_secperunit * dgratio)
961 		printf("%s: %" PRIu64 " trailing sectors not covered"
962 		    " by disklabel\n", dksc->sc_xname,
963 		    (dg->dg_secperunit * dgratio)
964 		    - (lp->d_secperunit * lpratio));
965 
966 	for (i=0; i < lp->d_npartitions; i++) {
967 		uint64_t pend;
968 
969 		pp = &lp->d_partitions[i];
970 		pend = pp->p_offset + pp->p_size;
971 		if (pend * lpratio > dg->dg_secperunit * dgratio)
972 			printf("WARNING: %s: end of partition `%c' exceeds "
973 			    "the size of %s (%" PRIu64 ")\n", dksc->sc_xname,
974 			    'a' + i, dksc->sc_xname,
975 			    dg->dg_secperunit * dgratio);
976 	}
977 }
978 
979 /*
980  * Heuristic to conjure a disklabel if reading a disklabel failed.
981  *
982  * This is to allow the raw partition to be used for a filesystem
983  * without caring about the write protected label sector.
984  *
985  * If the driver provides it's own callback, use that instead.
986  */
987 /* ARGSUSED */
988 static void
989 dk_makedisklabel(struct dk_softc *dksc)
990 {
991 	const struct dkdriver *dkd = dksc->sc_dkdev.dk_driver;
992 	struct  disklabel *lp = dksc->sc_dkdev.dk_label;
993 
994 	strlcpy(lp->d_packname, "default label", sizeof(lp->d_packname));
995 
996 	if (dkd->d_label)
997 		dkd->d_label(dksc->sc_dev, lp);
998 	else
999 		lp->d_partitions[RAW_PART].p_fstype = FS_BSDFFS;
1000 
1001 	lp->d_checksum = dkcksum(lp);
1002 }
1003 
1004 MODULE(MODULE_CLASS_MISC, dk_subr, NULL);
1005 
1006 static int
1007 dk_subr_modcmd(modcmd_t cmd, void *arg)
1008 {
1009 	switch (cmd) {
1010 	case MODULE_CMD_INIT:
1011 	case MODULE_CMD_FINI:
1012 		return 0;
1013 	case MODULE_CMD_STAT:
1014 	case MODULE_CMD_AUTOUNLOAD:
1015 	default:
1016 		return ENOTTY;
1017 	}
1018 }
1019