xref: /freebsd/sys/geom/geom_disk.c (revision 595e514d0df2bac5b813d35f83e32875dbf16a83)
1 /*-
2  * Copyright (c) 2002 Poul-Henning Kamp
3  * Copyright (c) 2002 Networks Associates Technology, Inc.
4  * All rights reserved.
5  *
6  * This software was developed for the FreeBSD Project by Poul-Henning Kamp
7  * and NAI Labs, the Security Research Division of Network Associates, Inc.
8  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
9  * DARPA CHATS research program.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. The names of the authors may not be used to endorse or promote
20  *    products derived from this software without specific prior written
21  *    permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include "opt_geom.h"
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/sysctl.h>
45 #include <sys/bio.h>
46 #include <sys/ctype.h>
47 #include <sys/fcntl.h>
48 #include <sys/malloc.h>
49 #include <sys/sbuf.h>
50 #include <sys/sysctl.h>
51 #include <sys/devicestat.h>
52 #include <machine/md_var.h>
53 
54 #include <sys/lock.h>
55 #include <sys/mutex.h>
56 #include <geom/geom.h>
57 #include <geom/geom_disk.h>
58 #include <geom/geom_int.h>
59 
60 #include <dev/led/led.h>
61 
62 struct g_disk_softc {
63 	struct mtx		 done_mtx;
64 	struct disk		*dp;
65 	struct sysctl_ctx_list	sysctl_ctx;
66 	struct sysctl_oid	*sysctl_tree;
67 	char			led[64];
68 	uint32_t		state;
69 };
70 
71 static g_access_t g_disk_access;
72 static g_start_t g_disk_start;
73 static g_ioctl_t g_disk_ioctl;
74 static g_dumpconf_t g_disk_dumpconf;
75 static g_provgone_t g_disk_providergone;
76 
77 static struct g_class g_disk_class = {
78 	.name = G_DISK_CLASS_NAME,
79 	.version = G_VERSION,
80 	.start = g_disk_start,
81 	.access = g_disk_access,
82 	.ioctl = g_disk_ioctl,
83 	.providergone = g_disk_providergone,
84 	.dumpconf = g_disk_dumpconf,
85 };
86 
87 SYSCTL_DECL(_kern_geom);
88 static SYSCTL_NODE(_kern_geom, OID_AUTO, disk, CTLFLAG_RW, 0,
89     "GEOM_DISK stuff");
90 
91 DECLARE_GEOM_CLASS(g_disk_class, g_disk);
92 
93 static void __inline
94 g_disk_lock_giant(struct disk *dp)
95 {
96 
97 	if (dp->d_flags & DISKFLAG_NEEDSGIANT)
98 		mtx_lock(&Giant);
99 }
100 
101 static void __inline
102 g_disk_unlock_giant(struct disk *dp)
103 {
104 
105 	if (dp->d_flags & DISKFLAG_NEEDSGIANT)
106 		mtx_unlock(&Giant);
107 }
108 
109 static int
110 g_disk_access(struct g_provider *pp, int r, int w, int e)
111 {
112 	struct disk *dp;
113 	struct g_disk_softc *sc;
114 	int error;
115 
116 	g_trace(G_T_ACCESS, "g_disk_access(%s, %d, %d, %d)",
117 	    pp->name, r, w, e);
118 	g_topology_assert();
119 	sc = pp->private;
120 	if (sc == NULL || (dp = sc->dp) == NULL || dp->d_destroyed) {
121 		/*
122 		 * Allow decreasing access count even if disk is not
123 		 * avaliable anymore.
124 		 */
125 		if (r <= 0 && w <= 0 && e <= 0)
126 			return (0);
127 		return (ENXIO);
128 	}
129 	r += pp->acr;
130 	w += pp->acw;
131 	e += pp->ace;
132 	error = 0;
133 	if ((pp->acr + pp->acw + pp->ace) == 0 && (r + w + e) > 0) {
134 		if (dp->d_open != NULL) {
135 			g_disk_lock_giant(dp);
136 			error = dp->d_open(dp);
137 			if (bootverbose && error != 0)
138 				printf("Opened disk %s -> %d\n",
139 				    pp->name, error);
140 			g_disk_unlock_giant(dp);
141 		}
142 		pp->mediasize = dp->d_mediasize;
143 		pp->sectorsize = dp->d_sectorsize;
144 		if (dp->d_maxsize == 0) {
145 			printf("WARNING: Disk drive %s%d has no d_maxsize\n",
146 			    dp->d_name, dp->d_unit);
147 			dp->d_maxsize = DFLTPHYS;
148 		}
149 		if (dp->d_flags & DISKFLAG_CANDELETE) {
150 			if (bootverbose && dp->d_delmaxsize == 0) {
151 				printf("WARNING: Disk drive %s%d has no d_delmaxsize\n",
152 				    dp->d_name, dp->d_unit);
153 				dp->d_delmaxsize = dp->d_maxsize;
154 			}
155 		} else {
156 			dp->d_delmaxsize = 0;
157 		}
158 		pp->stripeoffset = dp->d_stripeoffset;
159 		pp->stripesize = dp->d_stripesize;
160 		dp->d_flags |= DISKFLAG_OPEN;
161 	} else if ((pp->acr + pp->acw + pp->ace) > 0 && (r + w + e) == 0) {
162 		if (dp->d_close != NULL) {
163 			g_disk_lock_giant(dp);
164 			error = dp->d_close(dp);
165 			if (error != 0)
166 				printf("Closed disk %s -> %d\n",
167 				    pp->name, error);
168 			g_disk_unlock_giant(dp);
169 		}
170 		sc->state = G_STATE_ACTIVE;
171 		if (sc->led[0] != 0)
172 			led_set(sc->led, "0");
173 		dp->d_flags &= ~DISKFLAG_OPEN;
174 	}
175 	return (error);
176 }
177 
178 static void
179 g_disk_kerneldump(struct bio *bp, struct disk *dp)
180 {
181 	struct g_kerneldump *gkd;
182 	struct g_geom *gp;
183 
184 	gkd = (struct g_kerneldump*)bp->bio_data;
185 	gp = bp->bio_to->geom;
186 	g_trace(G_T_TOPOLOGY, "g_disk_kernedump(%s, %jd, %jd)",
187 		gp->name, (intmax_t)gkd->offset, (intmax_t)gkd->length);
188 	if (dp->d_dump == NULL) {
189 		g_io_deliver(bp, ENODEV);
190 		return;
191 	}
192 	gkd->di.dumper = dp->d_dump;
193 	gkd->di.priv = dp;
194 	gkd->di.blocksize = dp->d_sectorsize;
195 	gkd->di.maxiosize = dp->d_maxsize;
196 	gkd->di.mediaoffset = gkd->offset;
197 	if ((gkd->offset + gkd->length) > dp->d_mediasize)
198 		gkd->length = dp->d_mediasize - gkd->offset;
199 	gkd->di.mediasize = gkd->length;
200 	g_io_deliver(bp, 0);
201 }
202 
203 static void
204 g_disk_setstate(struct bio *bp, struct g_disk_softc *sc)
205 {
206 	const char *cmd;
207 
208 	memcpy(&sc->state, bp->bio_data, sizeof(sc->state));
209 	if (sc->led[0] != 0) {
210 		switch (sc->state) {
211 		case G_STATE_FAILED:
212 			cmd = "1";
213 			break;
214 		case G_STATE_REBUILD:
215 			cmd = "f5";
216 			break;
217 		case G_STATE_RESYNC:
218 			cmd = "f1";
219 			break;
220 		default:
221 			cmd = "0";
222 			break;
223 		}
224 		led_set(sc->led, cmd);
225 	}
226 	g_io_deliver(bp, 0);
227 }
228 
229 static void
230 g_disk_done(struct bio *bp)
231 {
232 	struct bio *bp2;
233 	struct g_disk_softc *sc;
234 
235 	/* See "notes" for why we need a mutex here */
236 	/* XXX: will witness accept a mix of Giant/unGiant drivers here ? */
237 	bp2 = bp->bio_parent;
238 	sc = bp2->bio_to->private;
239 	bp->bio_completed = bp->bio_length - bp->bio_resid;
240 	mtx_lock(&sc->done_mtx);
241 	if (bp2->bio_error == 0)
242 		bp2->bio_error = bp->bio_error;
243 	bp2->bio_completed += bp->bio_completed;
244 	if ((bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE)) != 0)
245 		devstat_end_transaction_bio(sc->dp->d_devstat, bp);
246 	g_destroy_bio(bp);
247 	bp2->bio_inbed++;
248 	if (bp2->bio_children == bp2->bio_inbed) {
249 		bp2->bio_resid = bp2->bio_bcount - bp2->bio_completed;
250 		g_io_deliver(bp2, bp2->bio_error);
251 	}
252 	mtx_unlock(&sc->done_mtx);
253 }
254 
255 static int
256 g_disk_ioctl(struct g_provider *pp, u_long cmd, void * data, int fflag, struct thread *td)
257 {
258 	struct disk *dp;
259 	struct g_disk_softc *sc;
260 	int error;
261 
262 	sc = pp->private;
263 	dp = sc->dp;
264 
265 	if (dp->d_ioctl == NULL)
266 		return (ENOIOCTL);
267 	g_disk_lock_giant(dp);
268 	error = dp->d_ioctl(dp, cmd, data, fflag, td);
269 	g_disk_unlock_giant(dp);
270 	return (error);
271 }
272 
273 static void
274 g_disk_start(struct bio *bp)
275 {
276 	struct bio *bp2, *bp3;
277 	struct disk *dp;
278 	struct g_disk_softc *sc;
279 	int error;
280 	off_t off;
281 
282 	sc = bp->bio_to->private;
283 	if (sc == NULL || (dp = sc->dp) == NULL || dp->d_destroyed) {
284 		g_io_deliver(bp, ENXIO);
285 		return;
286 	}
287 	error = EJUSTRETURN;
288 	switch(bp->bio_cmd) {
289 	case BIO_DELETE:
290 		if (!(dp->d_flags & DISKFLAG_CANDELETE)) {
291 			error = EOPNOTSUPP;
292 			break;
293 		}
294 		/* fall-through */
295 	case BIO_READ:
296 	case BIO_WRITE:
297 		off = 0;
298 		bp3 = NULL;
299 		bp2 = g_clone_bio(bp);
300 		if (bp2 == NULL) {
301 			error = ENOMEM;
302 			break;
303 		}
304 		do {
305 			off_t d_maxsize;
306 
307 			d_maxsize = (bp->bio_cmd == BIO_DELETE) ?
308 			    dp->d_delmaxsize : dp->d_maxsize;
309 			bp2->bio_offset += off;
310 			bp2->bio_length -= off;
311 			if ((bp->bio_flags & BIO_UNMAPPED) == 0) {
312 				bp2->bio_data += off;
313 			} else {
314 				KASSERT((dp->d_flags & DISKFLAG_UNMAPPED_BIO)
315 				    != 0,
316 				    ("unmapped bio not supported by disk %s",
317 				    dp->d_name));
318 				bp2->bio_ma += off / PAGE_SIZE;
319 				bp2->bio_ma_offset += off;
320 				bp2->bio_ma_offset %= PAGE_SIZE;
321 				bp2->bio_ma_n -= off / PAGE_SIZE;
322 			}
323 			if (bp2->bio_length > d_maxsize) {
324 				/*
325 				 * XXX: If we have a stripesize we should really
326 				 * use it here. Care should be taken in the delete
327 				 * case if this is done as deletes can be very
328 				 * sensitive to size given how they are processed.
329 				 */
330 				bp2->bio_length = d_maxsize;
331 				if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
332 					bp2->bio_ma_n = howmany(
333 					    bp2->bio_ma_offset +
334 					    bp2->bio_length, PAGE_SIZE);
335 				}
336 				off += d_maxsize;
337 				/*
338 				 * To avoid a race, we need to grab the next bio
339 				 * before we schedule this one.  See "notes".
340 				 */
341 				bp3 = g_clone_bio(bp);
342 				if (bp3 == NULL)
343 					bp->bio_error = ENOMEM;
344 			}
345 			bp2->bio_done = g_disk_done;
346 			bp2->bio_pblkno = bp2->bio_offset / dp->d_sectorsize;
347 			bp2->bio_bcount = bp2->bio_length;
348 			bp2->bio_disk = dp;
349 			devstat_start_transaction_bio(dp->d_devstat, bp2);
350 			g_disk_lock_giant(dp);
351 			dp->d_strategy(bp2);
352 			g_disk_unlock_giant(dp);
353 			bp2 = bp3;
354 			bp3 = NULL;
355 		} while (bp2 != NULL);
356 		break;
357 	case BIO_GETATTR:
358 		/* Give the driver a chance to override */
359 		if (dp->d_getattr != NULL) {
360 			if (bp->bio_disk == NULL)
361 				bp->bio_disk = dp;
362 			error = dp->d_getattr(bp);
363 			if (error != -1)
364 				break;
365 			error = EJUSTRETURN;
366 		}
367 		if (g_handleattr_int(bp, "GEOM::candelete",
368 		    (dp->d_flags & DISKFLAG_CANDELETE) != 0))
369 			break;
370 		else if (g_handleattr_int(bp, "GEOM::fwsectors",
371 		    dp->d_fwsectors))
372 			break;
373 		else if (g_handleattr_int(bp, "GEOM::fwheads", dp->d_fwheads))
374 			break;
375 		else if (g_handleattr_off_t(bp, "GEOM::frontstuff", 0))
376 			break;
377 		else if (g_handleattr_str(bp, "GEOM::ident", dp->d_ident))
378 			break;
379 		else if (g_handleattr(bp, "GEOM::hba_vendor",
380 		    &dp->d_hba_vendor, 2))
381 			break;
382 		else if (g_handleattr(bp, "GEOM::hba_device",
383 		    &dp->d_hba_device, 2))
384 			break;
385 		else if (g_handleattr(bp, "GEOM::hba_subvendor",
386 		    &dp->d_hba_subvendor, 2))
387 			break;
388 		else if (g_handleattr(bp, "GEOM::hba_subdevice",
389 		    &dp->d_hba_subdevice, 2))
390 			break;
391 		else if (!strcmp(bp->bio_attribute, "GEOM::kerneldump"))
392 			g_disk_kerneldump(bp, dp);
393 		else if (!strcmp(bp->bio_attribute, "GEOM::setstate"))
394 			g_disk_setstate(bp, sc);
395 		else
396 			error = ENOIOCTL;
397 		break;
398 	case BIO_FLUSH:
399 		g_trace(G_T_BIO, "g_disk_flushcache(%s)",
400 		    bp->bio_to->name);
401 		if (!(dp->d_flags & DISKFLAG_CANFLUSHCACHE)) {
402 			error = EOPNOTSUPP;
403 			break;
404 		}
405 		bp2 = g_clone_bio(bp);
406 		if (bp2 == NULL) {
407 			g_io_deliver(bp, ENOMEM);
408 			return;
409 		}
410 		bp2->bio_done = g_disk_done;
411 		bp2->bio_disk = dp;
412 		g_disk_lock_giant(dp);
413 		dp->d_strategy(bp2);
414 		g_disk_unlock_giant(dp);
415 		break;
416 	default:
417 		error = EOPNOTSUPP;
418 		break;
419 	}
420 	if (error != EJUSTRETURN)
421 		g_io_deliver(bp, error);
422 	return;
423 }
424 
425 static void
426 g_disk_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
427 {
428 	struct disk *dp;
429 	struct g_disk_softc *sc;
430 
431 	sc = gp->softc;
432 	if (sc == NULL || (dp = sc->dp) == NULL)
433 		return;
434 	if (indent == NULL) {
435 		sbuf_printf(sb, " hd %u", dp->d_fwheads);
436 		sbuf_printf(sb, " sc %u", dp->d_fwsectors);
437 		return;
438 	}
439 	if (pp != NULL) {
440 		sbuf_printf(sb, "%s<fwheads>%u</fwheads>\n",
441 		    indent, dp->d_fwheads);
442 		sbuf_printf(sb, "%s<fwsectors>%u</fwsectors>\n",
443 		    indent, dp->d_fwsectors);
444 		sbuf_printf(sb, "%s<ident>%s</ident>\n", indent, dp->d_ident);
445 		sbuf_printf(sb, "%s<descr>%s</descr>\n", indent, dp->d_descr);
446 	}
447 }
448 
449 static void
450 g_disk_resize(void *ptr, int flag)
451 {
452 	struct disk *dp;
453 	struct g_geom *gp;
454 	struct g_provider *pp;
455 
456 	if (flag == EV_CANCEL)
457 		return;
458 	g_topology_assert();
459 
460 	dp = ptr;
461 	gp = dp->d_geom;
462 
463 	if (dp->d_destroyed || gp == NULL)
464 		return;
465 
466 	LIST_FOREACH(pp, &gp->provider, provider) {
467 		if (pp->sectorsize != 0 &&
468 		    pp->sectorsize != dp->d_sectorsize)
469 			g_wither_provider(pp, ENXIO);
470 		else
471 			g_resize_provider(pp, dp->d_mediasize);
472 	}
473 }
474 
475 static void
476 g_disk_create(void *arg, int flag)
477 {
478 	struct g_geom *gp;
479 	struct g_provider *pp;
480 	struct disk *dp;
481 	struct g_disk_softc *sc;
482 	char tmpstr[80];
483 
484 	if (flag == EV_CANCEL)
485 		return;
486 	g_topology_assert();
487 	dp = arg;
488 	sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
489 	mtx_init(&sc->done_mtx, "g_disk_done", NULL, MTX_DEF);
490 	sc->dp = dp;
491 	gp = g_new_geomf(&g_disk_class, "%s%d", dp->d_name, dp->d_unit);
492 	gp->softc = sc;
493 	pp = g_new_providerf(gp, "%s", gp->name);
494 	pp->mediasize = dp->d_mediasize;
495 	pp->sectorsize = dp->d_sectorsize;
496 	pp->stripeoffset = dp->d_stripeoffset;
497 	pp->stripesize = dp->d_stripesize;
498 	if ((dp->d_flags & DISKFLAG_UNMAPPED_BIO) != 0)
499 		pp->flags |= G_PF_ACCEPT_UNMAPPED;
500 	if (bootverbose)
501 		printf("GEOM: new disk %s\n", gp->name);
502 	sysctl_ctx_init(&sc->sysctl_ctx);
503 	snprintf(tmpstr, sizeof(tmpstr), "GEOM disk %s", gp->name);
504 	sc->sysctl_tree = SYSCTL_ADD_NODE(&sc->sysctl_ctx,
505 		SYSCTL_STATIC_CHILDREN(_kern_geom_disk), OID_AUTO, gp->name,
506 		CTLFLAG_RD, 0, tmpstr);
507 	if (sc->sysctl_tree != NULL) {
508 		snprintf(tmpstr, sizeof(tmpstr),
509 		    "kern.geom.disk.%s.led", gp->name);
510 		TUNABLE_STR_FETCH(tmpstr, sc->led, sizeof(sc->led));
511 		SYSCTL_ADD_STRING(&sc->sysctl_ctx,
512 		    SYSCTL_CHILDREN(sc->sysctl_tree), OID_AUTO, "led",
513 		    CTLFLAG_RW | CTLFLAG_TUN, sc->led, sizeof(sc->led),
514 		    "LED name");
515 	}
516 	pp->private = sc;
517 	dp->d_geom = gp;
518 	g_error_provider(pp, 0);
519 }
520 
521 /*
522  * We get this callback after all of the consumers have gone away, and just
523  * before the provider is freed.  If the disk driver provided a d_gone
524  * callback, let them know that it is okay to free resources -- they won't
525  * be getting any more accesses from GEOM.
526  */
527 static void
528 g_disk_providergone(struct g_provider *pp)
529 {
530 	struct disk *dp;
531 	struct g_disk_softc *sc;
532 
533 	sc = (struct g_disk_softc *)pp->private;
534 	dp = sc->dp;
535 	if (dp != NULL && dp->d_gone != NULL)
536 		dp->d_gone(dp);
537 	if (sc->sysctl_tree != NULL) {
538 		sysctl_ctx_free(&sc->sysctl_ctx);
539 		sc->sysctl_tree = NULL;
540 	}
541 	if (sc->led[0] != 0) {
542 		led_set(sc->led, "0");
543 		sc->led[0] = 0;
544 	}
545 	pp->private = NULL;
546 	pp->geom->softc = NULL;
547 	mtx_destroy(&sc->done_mtx);
548 	g_free(sc);
549 }
550 
551 static void
552 g_disk_destroy(void *ptr, int flag)
553 {
554 	struct disk *dp;
555 	struct g_geom *gp;
556 	struct g_disk_softc *sc;
557 
558 	g_topology_assert();
559 	dp = ptr;
560 	gp = dp->d_geom;
561 	if (gp != NULL) {
562 		sc = gp->softc;
563 		if (sc != NULL)
564 			sc->dp = NULL;
565 		dp->d_geom = NULL;
566 		g_wither_geom(gp, ENXIO);
567 	}
568 	g_free(dp);
569 }
570 
571 /*
572  * We only allow printable characters in disk ident,
573  * the rest is converted to 'x<HH>'.
574  */
575 static void
576 g_disk_ident_adjust(char *ident, size_t size)
577 {
578 	char *p, tmp[4], newid[DISK_IDENT_SIZE];
579 
580 	newid[0] = '\0';
581 	for (p = ident; *p != '\0'; p++) {
582 		if (isprint(*p)) {
583 			tmp[0] = *p;
584 			tmp[1] = '\0';
585 		} else {
586 			snprintf(tmp, sizeof(tmp), "x%02hhx",
587 			    *(unsigned char *)p);
588 		}
589 		if (strlcat(newid, tmp, sizeof(newid)) >= sizeof(newid))
590 			break;
591 	}
592 	bzero(ident, size);
593 	strlcpy(ident, newid, size);
594 }
595 
596 struct disk *
597 disk_alloc(void)
598 {
599 
600 	return (g_malloc(sizeof(struct disk), M_WAITOK | M_ZERO));
601 }
602 
603 void
604 disk_create(struct disk *dp, int version)
605 {
606 
607 	if (version != DISK_VERSION_02) {
608 		printf("WARNING: Attempt to add disk %s%d %s",
609 		    dp->d_name, dp->d_unit,
610 		    " using incompatible ABI version of disk(9)\n");
611 		printf("WARNING: Ignoring disk %s%d\n",
612 		    dp->d_name, dp->d_unit);
613 		return;
614 	}
615 	KASSERT(dp->d_strategy != NULL, ("disk_create need d_strategy"));
616 	KASSERT(dp->d_name != NULL, ("disk_create need d_name"));
617 	KASSERT(*dp->d_name != 0, ("disk_create need d_name"));
618 	KASSERT(strlen(dp->d_name) < SPECNAMELEN - 4, ("disk name too long"));
619 	if (dp->d_devstat == NULL)
620 		dp->d_devstat = devstat_new_entry(dp->d_name, dp->d_unit,
621 		    dp->d_sectorsize, DEVSTAT_ALL_SUPPORTED,
622 		    DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
623 	dp->d_geom = NULL;
624 	g_disk_ident_adjust(dp->d_ident, sizeof(dp->d_ident));
625 	g_post_event(g_disk_create, dp, M_WAITOK, dp, NULL);
626 }
627 
628 void
629 disk_destroy(struct disk *dp)
630 {
631 
632 	g_cancel_event(dp);
633 	dp->d_destroyed = 1;
634 	if (dp->d_devstat != NULL)
635 		devstat_remove_entry(dp->d_devstat);
636 	g_post_event(g_disk_destroy, dp, M_WAITOK, NULL);
637 }
638 
639 void
640 disk_gone(struct disk *dp)
641 {
642 	struct g_geom *gp;
643 	struct g_provider *pp;
644 
645 	gp = dp->d_geom;
646 	if (gp != NULL) {
647 		pp = LIST_FIRST(&gp->provider);
648 		if (pp != NULL) {
649 			KASSERT(LIST_NEXT(pp, provider) == NULL,
650 			    ("geom %p has more than one provider", gp));
651 			g_wither_provider(pp, ENXIO);
652 		}
653 	}
654 }
655 
656 void
657 disk_attr_changed(struct disk *dp, const char *attr, int flag)
658 {
659 	struct g_geom *gp;
660 	struct g_provider *pp;
661 
662 	gp = dp->d_geom;
663 	if (gp != NULL)
664 		LIST_FOREACH(pp, &gp->provider, provider)
665 			(void)g_attr_changed(pp, attr, flag);
666 }
667 
668 void
669 disk_media_changed(struct disk *dp, int flag)
670 {
671 	struct g_geom *gp;
672 	struct g_provider *pp;
673 
674 	gp = dp->d_geom;
675 	if (gp != NULL) {
676 		pp = LIST_FIRST(&gp->provider);
677 		if (pp != NULL) {
678 			KASSERT(LIST_NEXT(pp, provider) == NULL,
679 			    ("geom %p has more than one provider", gp));
680 			g_media_changed(pp, flag);
681 		}
682 	}
683 }
684 
685 void
686 disk_media_gone(struct disk *dp, int flag)
687 {
688 	struct g_geom *gp;
689 	struct g_provider *pp;
690 
691 	gp = dp->d_geom;
692 	if (gp != NULL) {
693 		pp = LIST_FIRST(&gp->provider);
694 		if (pp != NULL) {
695 			KASSERT(LIST_NEXT(pp, provider) == NULL,
696 			    ("geom %p has more than one provider", gp));
697 			g_media_gone(pp, flag);
698 		}
699 	}
700 }
701 
702 int
703 disk_resize(struct disk *dp, int flag)
704 {
705 
706 	if (dp->d_destroyed || dp->d_geom == NULL)
707 		return (0);
708 
709 	return (g_post_event(g_disk_resize, dp, flag, NULL));
710 }
711 
712 static void
713 g_kern_disks(void *p, int flag __unused)
714 {
715 	struct sbuf *sb;
716 	struct g_geom *gp;
717 	char *sp;
718 
719 	sb = p;
720 	sp = "";
721 	g_topology_assert();
722 	LIST_FOREACH(gp, &g_disk_class.geom, geom) {
723 		sbuf_printf(sb, "%s%s", sp, gp->name);
724 		sp = " ";
725 	}
726 	sbuf_finish(sb);
727 }
728 
729 static int
730 sysctl_disks(SYSCTL_HANDLER_ARGS)
731 {
732 	int error;
733 	struct sbuf *sb;
734 
735 	sb = sbuf_new_auto();
736 	g_waitfor_event(g_kern_disks, sb, M_WAITOK, NULL);
737 	error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
738 	sbuf_delete(sb);
739 	return error;
740 }
741 
742 SYSCTL_PROC(_kern, OID_AUTO, disks,
743     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
744     sysctl_disks, "A", "names of available disks");
745