xref: /freebsd/sys/geom/geom_disk.c (revision c6ec7d31830ab1c80edae95ad5e4b9dba10c47ac)
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 disk		*dp;
64 	struct sysctl_ctx_list	sysctl_ctx;
65 	struct sysctl_oid	*sysctl_tree;
66 	char			led[64];
67 	uint32_t		state;
68 };
69 
70 static struct mtx g_disk_done_mtx;
71 
72 static g_access_t g_disk_access;
73 static g_init_t g_disk_init;
74 static g_fini_t g_disk_fini;
75 static g_start_t g_disk_start;
76 static g_ioctl_t g_disk_ioctl;
77 static g_dumpconf_t g_disk_dumpconf;
78 static g_provgone_t g_disk_providergone;
79 
80 static struct g_class g_disk_class = {
81 	.name = "DISK",
82 	.version = G_VERSION,
83 	.init = g_disk_init,
84 	.fini = g_disk_fini,
85 	.start = g_disk_start,
86 	.access = g_disk_access,
87 	.ioctl = g_disk_ioctl,
88 	.providergone = g_disk_providergone,
89 	.dumpconf = g_disk_dumpconf,
90 };
91 
92 SYSCTL_DECL(_kern_geom);
93 static SYSCTL_NODE(_kern_geom, OID_AUTO, disk, CTLFLAG_RW, 0,
94     "GEOM_DISK stuff");
95 
96 static void
97 g_disk_init(struct g_class *mp __unused)
98 {
99 
100 	mtx_init(&g_disk_done_mtx, "g_disk_done", NULL, MTX_DEF);
101 }
102 
103 static void
104 g_disk_fini(struct g_class *mp __unused)
105 {
106 
107 	mtx_destroy(&g_disk_done_mtx);
108 }
109 
110 DECLARE_GEOM_CLASS(g_disk_class, g_disk);
111 
112 static void __inline
113 g_disk_lock_giant(struct disk *dp)
114 {
115 
116 	if (dp->d_flags & DISKFLAG_NEEDSGIANT)
117 		mtx_lock(&Giant);
118 }
119 
120 static void __inline
121 g_disk_unlock_giant(struct disk *dp)
122 {
123 
124 	if (dp->d_flags & DISKFLAG_NEEDSGIANT)
125 		mtx_unlock(&Giant);
126 }
127 
128 static int
129 g_disk_access(struct g_provider *pp, int r, int w, int e)
130 {
131 	struct disk *dp;
132 	struct g_disk_softc *sc;
133 	int error;
134 
135 	g_trace(G_T_ACCESS, "g_disk_access(%s, %d, %d, %d)",
136 	    pp->name, r, w, e);
137 	g_topology_assert();
138 	sc = pp->geom->softc;
139 	if (sc == NULL || (dp = sc->dp) == NULL || dp->d_destroyed) {
140 		/*
141 		 * Allow decreasing access count even if disk is not
142 		 * avaliable anymore.
143 		 */
144 		if (r <= 0 && w <= 0 && e <= 0)
145 			return (0);
146 		return (ENXIO);
147 	}
148 	r += pp->acr;
149 	w += pp->acw;
150 	e += pp->ace;
151 	error = 0;
152 	if ((pp->acr + pp->acw + pp->ace) == 0 && (r + w + e) > 0) {
153 		if (dp->d_open != NULL) {
154 			g_disk_lock_giant(dp);
155 			error = dp->d_open(dp);
156 			if (bootverbose && error != 0)
157 				printf("Opened disk %s -> %d\n",
158 				    pp->name, error);
159 			g_disk_unlock_giant(dp);
160 		}
161 		pp->mediasize = dp->d_mediasize;
162 		pp->sectorsize = dp->d_sectorsize;
163 		pp->stripeoffset = dp->d_stripeoffset;
164 		pp->stripesize = dp->d_stripesize;
165 		dp->d_flags |= DISKFLAG_OPEN;
166 		if (dp->d_maxsize == 0) {
167 			printf("WARNING: Disk drive %s%d has no d_maxsize\n",
168 			    dp->d_name, dp->d_unit);
169 			dp->d_maxsize = DFLTPHYS;
170 		}
171 	} else if ((pp->acr + pp->acw + pp->ace) > 0 && (r + w + e) == 0) {
172 		if (dp->d_close != NULL) {
173 			g_disk_lock_giant(dp);
174 			error = dp->d_close(dp);
175 			if (error != 0)
176 				printf("Closed disk %s -> %d\n",
177 				    pp->name, error);
178 			g_disk_unlock_giant(dp);
179 		}
180 		sc->state = G_STATE_ACTIVE;
181 		if (sc->led[0] != 0)
182 			led_set(sc->led, "0");
183 		dp->d_flags &= ~DISKFLAG_OPEN;
184 	}
185 	return (error);
186 }
187 
188 static void
189 g_disk_kerneldump(struct bio *bp, struct disk *dp)
190 {
191 	struct g_kerneldump *gkd;
192 	struct g_geom *gp;
193 
194 	gkd = (struct g_kerneldump*)bp->bio_data;
195 	gp = bp->bio_to->geom;
196 	g_trace(G_T_TOPOLOGY, "g_disk_kernedump(%s, %jd, %jd)",
197 		gp->name, (intmax_t)gkd->offset, (intmax_t)gkd->length);
198 	if (dp->d_dump == NULL) {
199 		g_io_deliver(bp, ENODEV);
200 		return;
201 	}
202 	gkd->di.dumper = dp->d_dump;
203 	gkd->di.priv = dp;
204 	gkd->di.blocksize = dp->d_sectorsize;
205 	gkd->di.maxiosize = dp->d_maxsize;
206 	gkd->di.mediaoffset = gkd->offset;
207 	if ((gkd->offset + gkd->length) > dp->d_mediasize)
208 		gkd->length = dp->d_mediasize - gkd->offset;
209 	gkd->di.mediasize = gkd->length;
210 	g_io_deliver(bp, 0);
211 }
212 
213 static void
214 g_disk_setstate(struct bio *bp, struct g_disk_softc *sc)
215 {
216 	const char *cmd;
217 
218 	memcpy(&sc->state, bp->bio_data, sizeof(sc->state));
219 	if (sc->led[0] != 0) {
220 		switch (sc->state) {
221 		case G_STATE_FAILED:
222 			cmd = "1";
223 			break;
224 		case G_STATE_REBUILD:
225 			cmd = "f5";
226 			break;
227 		case G_STATE_RESYNC:
228 			cmd = "f1";
229 			break;
230 		default:
231 			cmd = "0";
232 			break;
233 		}
234 		led_set(sc->led, cmd);
235 	}
236 	g_io_deliver(bp, 0);
237 }
238 
239 static void
240 g_disk_done(struct bio *bp)
241 {
242 	struct bio *bp2;
243 	struct disk *dp;
244 	struct g_disk_softc *sc;
245 
246 	/* See "notes" for why we need a mutex here */
247 	/* XXX: will witness accept a mix of Giant/unGiant drivers here ? */
248 	mtx_lock(&g_disk_done_mtx);
249 	bp->bio_completed = bp->bio_length - bp->bio_resid;
250 
251 	bp2 = bp->bio_parent;
252 	if (bp2->bio_error == 0)
253 		bp2->bio_error = bp->bio_error;
254 	bp2->bio_completed += bp->bio_completed;
255 	if ((bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE)) != 0 &&
256 	    (sc = bp2->bio_to->geom->softc) != NULL &&
257 	    (dp = sc->dp) != NULL) {
258 		devstat_end_transaction_bio(dp->d_devstat, bp);
259 	}
260 	g_destroy_bio(bp);
261 	bp2->bio_inbed++;
262 	if (bp2->bio_children == bp2->bio_inbed) {
263 		bp2->bio_resid = bp2->bio_bcount - bp2->bio_completed;
264 		g_io_deliver(bp2, bp2->bio_error);
265 	}
266 	mtx_unlock(&g_disk_done_mtx);
267 }
268 
269 static int
270 g_disk_ioctl(struct g_provider *pp, u_long cmd, void * data, int fflag, struct thread *td)
271 {
272 	struct g_geom *gp;
273 	struct disk *dp;
274 	struct g_disk_softc *sc;
275 	int error;
276 
277 	gp = pp->geom;
278 	sc = gp->softc;
279 	dp = sc->dp;
280 
281 	if (dp->d_ioctl == NULL)
282 		return (ENOIOCTL);
283 	g_disk_lock_giant(dp);
284 	error = dp->d_ioctl(dp, cmd, data, fflag, td);
285 	g_disk_unlock_giant(dp);
286 	return (error);
287 }
288 
289 static void
290 g_disk_start(struct bio *bp)
291 {
292 	struct bio *bp2, *bp3;
293 	struct disk *dp;
294 	struct g_disk_softc *sc;
295 	int error;
296 	off_t off;
297 
298 	sc = bp->bio_to->geom->softc;
299 	if (sc == NULL || (dp = sc->dp) == NULL || dp->d_destroyed) {
300 		g_io_deliver(bp, ENXIO);
301 		return;
302 	}
303 	error = EJUSTRETURN;
304 	switch(bp->bio_cmd) {
305 	case BIO_DELETE:
306 		if (!(dp->d_flags & DISKFLAG_CANDELETE)) {
307 			error = EOPNOTSUPP;
308 			break;
309 		}
310 		/* fall-through */
311 	case BIO_READ:
312 	case BIO_WRITE:
313 		off = 0;
314 		bp3 = NULL;
315 		bp2 = g_clone_bio(bp);
316 		if (bp2 == NULL) {
317 			error = ENOMEM;
318 			break;
319 		}
320 		do {
321 			bp2->bio_offset += off;
322 			bp2->bio_length -= off;
323 			bp2->bio_data += off;
324 			if (bp2->bio_length > dp->d_maxsize) {
325 				/*
326 				 * XXX: If we have a stripesize we should really
327 				 * use it here.
328 				 */
329 				bp2->bio_length = dp->d_maxsize;
330 				off += dp->d_maxsize;
331 				/*
332 				 * To avoid a race, we need to grab the next bio
333 				 * before we schedule this one.  See "notes".
334 				 */
335 				bp3 = g_clone_bio(bp);
336 				if (bp3 == NULL)
337 					bp->bio_error = ENOMEM;
338 			}
339 			bp2->bio_done = g_disk_done;
340 			bp2->bio_pblkno = bp2->bio_offset / dp->d_sectorsize;
341 			bp2->bio_bcount = bp2->bio_length;
342 			bp2->bio_disk = dp;
343 			devstat_start_transaction_bio(dp->d_devstat, bp2);
344 			g_disk_lock_giant(dp);
345 			dp->d_strategy(bp2);
346 			g_disk_unlock_giant(dp);
347 			bp2 = bp3;
348 			bp3 = NULL;
349 		} while (bp2 != NULL);
350 		break;
351 	case BIO_GETATTR:
352 		/* Give the driver a chance to override */
353 		if (dp->d_getattr != NULL) {
354 			if (bp->bio_disk == NULL)
355 				bp->bio_disk = dp;
356 			error = dp->d_getattr(bp);
357 			if (error != -1)
358 				break;
359 			error = EJUSTRETURN;
360 		}
361 		if (g_handleattr_int(bp, "GEOM::candelete",
362 		    (dp->d_flags & DISKFLAG_CANDELETE) != 0))
363 			break;
364 		else if (g_handleattr_int(bp, "GEOM::fwsectors",
365 		    dp->d_fwsectors))
366 			break;
367 		else if (g_handleattr_int(bp, "GEOM::fwheads", dp->d_fwheads))
368 			break;
369 		else if (g_handleattr_off_t(bp, "GEOM::frontstuff", 0))
370 			break;
371 		else if (g_handleattr_str(bp, "GEOM::ident", dp->d_ident))
372 			break;
373 		else if (g_handleattr(bp, "GEOM::hba_vendor",
374 		    &dp->d_hba_vendor, 2))
375 			break;
376 		else if (g_handleattr(bp, "GEOM::hba_device",
377 		    &dp->d_hba_device, 2))
378 			break;
379 		else if (g_handleattr(bp, "GEOM::hba_subvendor",
380 		    &dp->d_hba_subvendor, 2))
381 			break;
382 		else if (g_handleattr(bp, "GEOM::hba_subdevice",
383 		    &dp->d_hba_subdevice, 2))
384 			break;
385 		else if (!strcmp(bp->bio_attribute, "GEOM::kerneldump"))
386 			g_disk_kerneldump(bp, dp);
387 		else if (!strcmp(bp->bio_attribute, "GEOM::setstate"))
388 			g_disk_setstate(bp, sc);
389 		else
390 			error = ENOIOCTL;
391 		break;
392 	case BIO_FLUSH:
393 		g_trace(G_T_BIO, "g_disk_flushcache(%s)",
394 		    bp->bio_to->name);
395 		if (!(dp->d_flags & DISKFLAG_CANFLUSHCACHE)) {
396 			error = EOPNOTSUPP;
397 			break;
398 		}
399 		bp2 = g_clone_bio(bp);
400 		if (bp2 == NULL) {
401 			g_io_deliver(bp, ENOMEM);
402 			return;
403 		}
404 		bp2->bio_done = g_disk_done;
405 		bp2->bio_disk = dp;
406 		g_disk_lock_giant(dp);
407 		dp->d_strategy(bp2);
408 		g_disk_unlock_giant(dp);
409 		break;
410 	default:
411 		error = EOPNOTSUPP;
412 		break;
413 	}
414 	if (error != EJUSTRETURN)
415 		g_io_deliver(bp, error);
416 	return;
417 }
418 
419 static void
420 g_disk_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
421 {
422 	struct disk *dp;
423 	struct g_disk_softc *sc;
424 
425 	sc = gp->softc;
426 	if (sc == NULL || (dp = sc->dp) == NULL)
427 		return;
428 	if (indent == NULL) {
429 		sbuf_printf(sb, " hd %u", dp->d_fwheads);
430 		sbuf_printf(sb, " sc %u", dp->d_fwsectors);
431 		return;
432 	}
433 	if (pp != NULL) {
434 		sbuf_printf(sb, "%s<fwheads>%u</fwheads>\n",
435 		    indent, dp->d_fwheads);
436 		sbuf_printf(sb, "%s<fwsectors>%u</fwsectors>\n",
437 		    indent, dp->d_fwsectors);
438 		sbuf_printf(sb, "%s<ident>%s</ident>\n", indent, dp->d_ident);
439 		sbuf_printf(sb, "%s<descr>%s</descr>\n", indent, dp->d_descr);
440 	}
441 }
442 
443 static void
444 g_disk_resize(void *ptr, int flag)
445 {
446 	struct disk *dp;
447 	struct g_geom *gp;
448 	struct g_provider *pp;
449 
450 	if (flag == EV_CANCEL)
451 		return;
452 	g_topology_assert();
453 
454 	dp = ptr;
455 	gp = dp->d_geom;
456 
457 	if (dp->d_destroyed || gp == NULL)
458 		return;
459 
460 	LIST_FOREACH(pp, &gp->provider, provider) {
461 		if (pp->sectorsize != 0 &&
462 		    pp->sectorsize != dp->d_sectorsize)
463 			g_wither_provider(pp, ENXIO);
464 		else
465 			g_resize_provider(pp, dp->d_mediasize);
466 	}
467 }
468 
469 static void
470 g_disk_create(void *arg, int flag)
471 {
472 	struct g_geom *gp;
473 	struct g_provider *pp;
474 	struct disk *dp;
475 	struct g_disk_softc *sc;
476 	char tmpstr[80];
477 
478 	if (flag == EV_CANCEL)
479 		return;
480 	g_topology_assert();
481 	dp = arg;
482 	sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
483 	sc->dp = dp;
484 	gp = g_new_geomf(&g_disk_class, "%s%d", dp->d_name, dp->d_unit);
485 	gp->softc = sc;
486 	pp = g_new_providerf(gp, "%s", gp->name);
487 	pp->mediasize = dp->d_mediasize;
488 	pp->sectorsize = dp->d_sectorsize;
489 	pp->stripeoffset = dp->d_stripeoffset;
490 	pp->stripesize = dp->d_stripesize;
491 	if (bootverbose)
492 		printf("GEOM: new disk %s\n", gp->name);
493 	sysctl_ctx_init(&sc->sysctl_ctx);
494 	snprintf(tmpstr, sizeof(tmpstr), "GEOM disk %s", gp->name);
495 	sc->sysctl_tree = SYSCTL_ADD_NODE(&sc->sysctl_ctx,
496 		SYSCTL_STATIC_CHILDREN(_kern_geom_disk), OID_AUTO, gp->name,
497 		CTLFLAG_RD, 0, tmpstr);
498 	if (sc->sysctl_tree != NULL) {
499 		snprintf(tmpstr, sizeof(tmpstr),
500 		    "kern.geom.disk.%s.led", gp->name);
501 		TUNABLE_STR_FETCH(tmpstr, sc->led, sizeof(sc->led));
502 		SYSCTL_ADD_STRING(&sc->sysctl_ctx,
503 		    SYSCTL_CHILDREN(sc->sysctl_tree), OID_AUTO, "led",
504 		    CTLFLAG_RW | CTLFLAG_TUN, sc->led, sizeof(sc->led),
505 		    "LED name");
506 	}
507 	pp->private = sc;
508 	dp->d_geom = gp;
509 	g_error_provider(pp, 0);
510 }
511 
512 /*
513  * We get this callback after all of the consumers have gone away, and just
514  * before the provider is freed.  If the disk driver provided a d_gone
515  * callback, let them know that it is okay to free resources -- they won't
516  * be getting any more accesses from GEOM.
517  */
518 static void
519 g_disk_providergone(struct g_provider *pp)
520 {
521 	struct disk *dp;
522 	struct g_disk_softc *sc;
523 
524 	sc = (struct g_disk_softc *)pp->geom->softc;
525 
526 	/*
527 	 * If the softc is already NULL, then we've probably been through
528 	 * g_disk_destroy already; there is nothing for us to do anyway.
529 	 */
530 	if (sc == NULL)
531 		return;
532 
533 	dp = sc->dp;
534 
535 	if (dp->d_gone != NULL)
536 		dp->d_gone(dp);
537 }
538 
539 static void
540 g_disk_destroy(void *ptr, int flag)
541 {
542 	struct disk *dp;
543 	struct g_geom *gp;
544 	struct g_disk_softc *sc;
545 
546 	g_topology_assert();
547 	dp = ptr;
548 	gp = dp->d_geom;
549 	if (gp != NULL) {
550 		sc = gp->softc;
551 		if (sc->sysctl_tree != NULL) {
552 			sysctl_ctx_free(&sc->sysctl_ctx);
553 			sc->sysctl_tree = NULL;
554 		}
555 		if (sc->led[0] != 0) {
556 			led_set(sc->led, "0");
557 			sc->led[0] = 0;
558 		}
559 		g_free(sc);
560 		gp->softc = NULL;
561 		g_wither_geom(gp, ENXIO);
562 	}
563 	g_free(dp);
564 }
565 
566 /*
567  * We only allow printable characters in disk ident,
568  * the rest is converted to 'x<HH>'.
569  */
570 static void
571 g_disk_ident_adjust(char *ident, size_t size)
572 {
573 	char *p, tmp[4], newid[DISK_IDENT_SIZE];
574 
575 	newid[0] = '\0';
576 	for (p = ident; *p != '\0'; p++) {
577 		if (isprint(*p)) {
578 			tmp[0] = *p;
579 			tmp[1] = '\0';
580 		} else {
581 			snprintf(tmp, sizeof(tmp), "x%02hhx",
582 			    *(unsigned char *)p);
583 		}
584 		if (strlcat(newid, tmp, sizeof(newid)) >= sizeof(newid))
585 			break;
586 	}
587 	bzero(ident, size);
588 	strlcpy(ident, newid, size);
589 }
590 
591 struct disk *
592 disk_alloc(void)
593 {
594 
595 	return (g_malloc(sizeof(struct disk), M_WAITOK | M_ZERO));
596 }
597 
598 void
599 disk_create(struct disk *dp, int version)
600 {
601 
602 	if (version != DISK_VERSION_02) {
603 		printf("WARNING: Attempt to add disk %s%d %s",
604 		    dp->d_name, dp->d_unit,
605 		    " using incompatible ABI version of disk(9)\n");
606 		printf("WARNING: Ignoring disk %s%d\n",
607 		    dp->d_name, dp->d_unit);
608 		return;
609 	}
610 	KASSERT(dp->d_strategy != NULL, ("disk_create need d_strategy"));
611 	KASSERT(dp->d_name != NULL, ("disk_create need d_name"));
612 	KASSERT(*dp->d_name != 0, ("disk_create need d_name"));
613 	KASSERT(strlen(dp->d_name) < SPECNAMELEN - 4, ("disk name too long"));
614 	if (dp->d_devstat == NULL)
615 		dp->d_devstat = devstat_new_entry(dp->d_name, dp->d_unit,
616 		    dp->d_sectorsize, DEVSTAT_ALL_SUPPORTED,
617 		    DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
618 	dp->d_geom = NULL;
619 	g_disk_ident_adjust(dp->d_ident, sizeof(dp->d_ident));
620 	g_post_event(g_disk_create, dp, M_WAITOK, dp, NULL);
621 }
622 
623 void
624 disk_destroy(struct disk *dp)
625 {
626 
627 	g_cancel_event(dp);
628 	dp->d_destroyed = 1;
629 	if (dp->d_devstat != NULL)
630 		devstat_remove_entry(dp->d_devstat);
631 	g_post_event(g_disk_destroy, dp, M_WAITOK, NULL);
632 }
633 
634 void
635 disk_gone(struct disk *dp)
636 {
637 	struct g_geom *gp;
638 	struct g_provider *pp;
639 
640 	gp = dp->d_geom;
641 	if (gp != NULL) {
642 		pp = LIST_FIRST(&gp->provider);
643 		if (pp != NULL) {
644 			KASSERT(LIST_NEXT(pp, provider) == NULL,
645 			    ("geom %p has more than one provider", gp));
646 			g_wither_provider(pp, ENXIO);
647 		}
648 	}
649 }
650 
651 void
652 disk_attr_changed(struct disk *dp, const char *attr, int flag)
653 {
654 	struct g_geom *gp;
655 	struct g_provider *pp;
656 
657 	gp = dp->d_geom;
658 	if (gp != NULL)
659 		LIST_FOREACH(pp, &gp->provider, provider)
660 			(void)g_attr_changed(pp, attr, flag);
661 }
662 
663 void
664 disk_media_changed(struct disk *dp, int flag)
665 {
666 	struct g_geom *gp;
667 	struct g_provider *pp;
668 
669 	gp = dp->d_geom;
670 	if (gp != NULL) {
671 		LIST_FOREACH(pp, &gp->provider, provider)
672 			g_media_changed(pp, flag);
673 	}
674 }
675 
676 void
677 disk_media_gone(struct disk *dp, int flag)
678 {
679 	struct g_geom *gp;
680 	struct g_provider *pp;
681 
682 	gp = dp->d_geom;
683 	if (gp != NULL) {
684 		LIST_FOREACH(pp, &gp->provider, provider)
685 			g_media_gone(pp, flag);
686 	}
687 }
688 
689 int
690 disk_resize(struct disk *dp, int flag)
691 {
692 
693 	if (dp->d_destroyed || dp->d_geom == NULL)
694 		return (0);
695 
696 	return (g_post_event(g_disk_resize, dp, flag, NULL));
697 }
698 
699 static void
700 g_kern_disks(void *p, int flag __unused)
701 {
702 	struct sbuf *sb;
703 	struct g_geom *gp;
704 	char *sp;
705 
706 	sb = p;
707 	sp = "";
708 	g_topology_assert();
709 	LIST_FOREACH(gp, &g_disk_class.geom, geom) {
710 		sbuf_printf(sb, "%s%s", sp, gp->name);
711 		sp = " ";
712 	}
713 	sbuf_finish(sb);
714 }
715 
716 static int
717 sysctl_disks(SYSCTL_HANDLER_ARGS)
718 {
719 	int error;
720 	struct sbuf *sb;
721 
722 	sb = sbuf_new_auto();
723 	g_waitfor_event(g_kern_disks, sb, M_WAITOK, NULL);
724 	error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
725 	sbuf_delete(sb);
726 	return error;
727 }
728 
729 SYSCTL_PROC(_kern, OID_AUTO, disks,
730     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
731     sysctl_disks, "A", "names of available disks");
732