xref: /freebsd/sys/geom/geom_disk.c (revision d184218c18d067f8fd47203f54ab02a7b2ed9b11)
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 = "DISK",
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 		pp->stripeoffset = dp->d_stripeoffset;
145 		pp->stripesize = dp->d_stripesize;
146 		dp->d_flags |= DISKFLAG_OPEN;
147 		if (dp->d_maxsize == 0) {
148 			printf("WARNING: Disk drive %s%d has no d_maxsize\n",
149 			    dp->d_name, dp->d_unit);
150 			dp->d_maxsize = DFLTPHYS;
151 		}
152 	} else if ((pp->acr + pp->acw + pp->ace) > 0 && (r + w + e) == 0) {
153 		if (dp->d_close != NULL) {
154 			g_disk_lock_giant(dp);
155 			error = dp->d_close(dp);
156 			if (error != 0)
157 				printf("Closed disk %s -> %d\n",
158 				    pp->name, error);
159 			g_disk_unlock_giant(dp);
160 		}
161 		sc->state = G_STATE_ACTIVE;
162 		if (sc->led[0] != 0)
163 			led_set(sc->led, "0");
164 		dp->d_flags &= ~DISKFLAG_OPEN;
165 	}
166 	return (error);
167 }
168 
169 static void
170 g_disk_kerneldump(struct bio *bp, struct disk *dp)
171 {
172 	struct g_kerneldump *gkd;
173 	struct g_geom *gp;
174 
175 	gkd = (struct g_kerneldump*)bp->bio_data;
176 	gp = bp->bio_to->geom;
177 	g_trace(G_T_TOPOLOGY, "g_disk_kernedump(%s, %jd, %jd)",
178 		gp->name, (intmax_t)gkd->offset, (intmax_t)gkd->length);
179 	if (dp->d_dump == NULL) {
180 		g_io_deliver(bp, ENODEV);
181 		return;
182 	}
183 	gkd->di.dumper = dp->d_dump;
184 	gkd->di.priv = dp;
185 	gkd->di.blocksize = dp->d_sectorsize;
186 	gkd->di.maxiosize = dp->d_maxsize;
187 	gkd->di.mediaoffset = gkd->offset;
188 	if ((gkd->offset + gkd->length) > dp->d_mediasize)
189 		gkd->length = dp->d_mediasize - gkd->offset;
190 	gkd->di.mediasize = gkd->length;
191 	g_io_deliver(bp, 0);
192 }
193 
194 static void
195 g_disk_setstate(struct bio *bp, struct g_disk_softc *sc)
196 {
197 	const char *cmd;
198 
199 	memcpy(&sc->state, bp->bio_data, sizeof(sc->state));
200 	if (sc->led[0] != 0) {
201 		switch (sc->state) {
202 		case G_STATE_FAILED:
203 			cmd = "1";
204 			break;
205 		case G_STATE_REBUILD:
206 			cmd = "f5";
207 			break;
208 		case G_STATE_RESYNC:
209 			cmd = "f1";
210 			break;
211 		default:
212 			cmd = "0";
213 			break;
214 		}
215 		led_set(sc->led, cmd);
216 	}
217 	g_io_deliver(bp, 0);
218 }
219 
220 static void
221 g_disk_done(struct bio *bp)
222 {
223 	struct bio *bp2;
224 	struct g_disk_softc *sc;
225 
226 	/* See "notes" for why we need a mutex here */
227 	/* XXX: will witness accept a mix of Giant/unGiant drivers here ? */
228 	bp2 = bp->bio_parent;
229 	sc = bp2->bio_to->private;
230 	bp->bio_completed = bp->bio_length - bp->bio_resid;
231 	mtx_lock(&sc->done_mtx);
232 	if (bp2->bio_error == 0)
233 		bp2->bio_error = bp->bio_error;
234 	bp2->bio_completed += bp->bio_completed;
235 	if ((bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE)) != 0)
236 		devstat_end_transaction_bio(sc->dp->d_devstat, bp);
237 	g_destroy_bio(bp);
238 	bp2->bio_inbed++;
239 	if (bp2->bio_children == bp2->bio_inbed) {
240 		bp2->bio_resid = bp2->bio_bcount - bp2->bio_completed;
241 		g_io_deliver(bp2, bp2->bio_error);
242 	}
243 	mtx_unlock(&sc->done_mtx);
244 }
245 
246 static int
247 g_disk_ioctl(struct g_provider *pp, u_long cmd, void * data, int fflag, struct thread *td)
248 {
249 	struct disk *dp;
250 	struct g_disk_softc *sc;
251 	int error;
252 
253 	sc = pp->private;
254 	dp = sc->dp;
255 
256 	if (dp->d_ioctl == NULL)
257 		return (ENOIOCTL);
258 	g_disk_lock_giant(dp);
259 	error = dp->d_ioctl(dp, cmd, data, fflag, td);
260 	g_disk_unlock_giant(dp);
261 	return (error);
262 }
263 
264 static void
265 g_disk_start(struct bio *bp)
266 {
267 	struct bio *bp2, *bp3;
268 	struct disk *dp;
269 	struct g_disk_softc *sc;
270 	int error;
271 	off_t off;
272 
273 	sc = bp->bio_to->private;
274 	if (sc == NULL || (dp = sc->dp) == NULL || dp->d_destroyed) {
275 		g_io_deliver(bp, ENXIO);
276 		return;
277 	}
278 	error = EJUSTRETURN;
279 	switch(bp->bio_cmd) {
280 	case BIO_DELETE:
281 		if (!(dp->d_flags & DISKFLAG_CANDELETE)) {
282 			error = EOPNOTSUPP;
283 			break;
284 		}
285 		/* fall-through */
286 	case BIO_READ:
287 	case BIO_WRITE:
288 		off = 0;
289 		bp3 = NULL;
290 		bp2 = g_clone_bio(bp);
291 		if (bp2 == NULL) {
292 			error = ENOMEM;
293 			break;
294 		}
295 		do {
296 			bp2->bio_offset += off;
297 			bp2->bio_length -= off;
298 			if ((bp->bio_flags & BIO_UNMAPPED) == 0) {
299 				bp2->bio_data += off;
300 			} else {
301 				KASSERT((dp->d_flags & DISKFLAG_UNMAPPED_BIO)
302 				    != 0,
303 				    ("unmapped bio not supported by disk %s",
304 				    dp->d_name));
305 				bp2->bio_ma += off / PAGE_SIZE;
306 				bp2->bio_ma_offset += off;
307 				bp2->bio_ma_offset %= PAGE_SIZE;
308 				bp2->bio_ma_n -= off / PAGE_SIZE;
309 			}
310 			if (bp2->bio_length > dp->d_maxsize) {
311 				/*
312 				 * XXX: If we have a stripesize we should really
313 				 * use it here.
314 				 */
315 				bp2->bio_length = dp->d_maxsize;
316 				if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
317 					bp2->bio_ma_n = howmany(
318 					    bp2->bio_ma_offset +
319 					    bp2->bio_length, PAGE_SIZE);
320 				}
321 				off += dp->d_maxsize;
322 				/*
323 				 * To avoid a race, we need to grab the next bio
324 				 * before we schedule this one.  See "notes".
325 				 */
326 				bp3 = g_clone_bio(bp);
327 				if (bp3 == NULL)
328 					bp->bio_error = ENOMEM;
329 			}
330 			bp2->bio_done = g_disk_done;
331 			bp2->bio_pblkno = bp2->bio_offset / dp->d_sectorsize;
332 			bp2->bio_bcount = bp2->bio_length;
333 			bp2->bio_disk = dp;
334 			devstat_start_transaction_bio(dp->d_devstat, bp2);
335 			g_disk_lock_giant(dp);
336 			dp->d_strategy(bp2);
337 			g_disk_unlock_giant(dp);
338 			bp2 = bp3;
339 			bp3 = NULL;
340 		} while (bp2 != NULL);
341 		break;
342 	case BIO_GETATTR:
343 		/* Give the driver a chance to override */
344 		if (dp->d_getattr != NULL) {
345 			if (bp->bio_disk == NULL)
346 				bp->bio_disk = dp;
347 			error = dp->d_getattr(bp);
348 			if (error != -1)
349 				break;
350 			error = EJUSTRETURN;
351 		}
352 		if (g_handleattr_int(bp, "GEOM::candelete",
353 		    (dp->d_flags & DISKFLAG_CANDELETE) != 0))
354 			break;
355 		else if (g_handleattr_int(bp, "GEOM::fwsectors",
356 		    dp->d_fwsectors))
357 			break;
358 		else if (g_handleattr_int(bp, "GEOM::fwheads", dp->d_fwheads))
359 			break;
360 		else if (g_handleattr_off_t(bp, "GEOM::frontstuff", 0))
361 			break;
362 		else if (g_handleattr_str(bp, "GEOM::ident", dp->d_ident))
363 			break;
364 		else if (g_handleattr(bp, "GEOM::hba_vendor",
365 		    &dp->d_hba_vendor, 2))
366 			break;
367 		else if (g_handleattr(bp, "GEOM::hba_device",
368 		    &dp->d_hba_device, 2))
369 			break;
370 		else if (g_handleattr(bp, "GEOM::hba_subvendor",
371 		    &dp->d_hba_subvendor, 2))
372 			break;
373 		else if (g_handleattr(bp, "GEOM::hba_subdevice",
374 		    &dp->d_hba_subdevice, 2))
375 			break;
376 		else if (!strcmp(bp->bio_attribute, "GEOM::kerneldump"))
377 			g_disk_kerneldump(bp, dp);
378 		else if (!strcmp(bp->bio_attribute, "GEOM::setstate"))
379 			g_disk_setstate(bp, sc);
380 		else
381 			error = ENOIOCTL;
382 		break;
383 	case BIO_FLUSH:
384 		g_trace(G_T_BIO, "g_disk_flushcache(%s)",
385 		    bp->bio_to->name);
386 		if (!(dp->d_flags & DISKFLAG_CANFLUSHCACHE)) {
387 			error = EOPNOTSUPP;
388 			break;
389 		}
390 		bp2 = g_clone_bio(bp);
391 		if (bp2 == NULL) {
392 			g_io_deliver(bp, ENOMEM);
393 			return;
394 		}
395 		bp2->bio_done = g_disk_done;
396 		bp2->bio_disk = dp;
397 		g_disk_lock_giant(dp);
398 		dp->d_strategy(bp2);
399 		g_disk_unlock_giant(dp);
400 		break;
401 	default:
402 		error = EOPNOTSUPP;
403 		break;
404 	}
405 	if (error != EJUSTRETURN)
406 		g_io_deliver(bp, error);
407 	return;
408 }
409 
410 static void
411 g_disk_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
412 {
413 	struct disk *dp;
414 	struct g_disk_softc *sc;
415 
416 	sc = gp->softc;
417 	if (sc == NULL || (dp = sc->dp) == NULL)
418 		return;
419 	if (indent == NULL) {
420 		sbuf_printf(sb, " hd %u", dp->d_fwheads);
421 		sbuf_printf(sb, " sc %u", dp->d_fwsectors);
422 		return;
423 	}
424 	if (pp != NULL) {
425 		sbuf_printf(sb, "%s<fwheads>%u</fwheads>\n",
426 		    indent, dp->d_fwheads);
427 		sbuf_printf(sb, "%s<fwsectors>%u</fwsectors>\n",
428 		    indent, dp->d_fwsectors);
429 		sbuf_printf(sb, "%s<ident>%s</ident>\n", indent, dp->d_ident);
430 		sbuf_printf(sb, "%s<descr>%s</descr>\n", indent, dp->d_descr);
431 	}
432 }
433 
434 static void
435 g_disk_resize(void *ptr, int flag)
436 {
437 	struct disk *dp;
438 	struct g_geom *gp;
439 	struct g_provider *pp;
440 
441 	if (flag == EV_CANCEL)
442 		return;
443 	g_topology_assert();
444 
445 	dp = ptr;
446 	gp = dp->d_geom;
447 
448 	if (dp->d_destroyed || gp == NULL)
449 		return;
450 
451 	LIST_FOREACH(pp, &gp->provider, provider) {
452 		if (pp->sectorsize != 0 &&
453 		    pp->sectorsize != dp->d_sectorsize)
454 			g_wither_provider(pp, ENXIO);
455 		else
456 			g_resize_provider(pp, dp->d_mediasize);
457 	}
458 }
459 
460 static void
461 g_disk_create(void *arg, int flag)
462 {
463 	struct g_geom *gp;
464 	struct g_provider *pp;
465 	struct disk *dp;
466 	struct g_disk_softc *sc;
467 	char tmpstr[80];
468 
469 	if (flag == EV_CANCEL)
470 		return;
471 	g_topology_assert();
472 	dp = arg;
473 	sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
474 	mtx_init(&sc->done_mtx, "g_disk_done", NULL, MTX_DEF);
475 	sc->dp = dp;
476 	gp = g_new_geomf(&g_disk_class, "%s%d", dp->d_name, dp->d_unit);
477 	gp->softc = sc;
478 	pp = g_new_providerf(gp, "%s", gp->name);
479 	pp->mediasize = dp->d_mediasize;
480 	pp->sectorsize = dp->d_sectorsize;
481 	pp->stripeoffset = dp->d_stripeoffset;
482 	pp->stripesize = dp->d_stripesize;
483 	if ((dp->d_flags & DISKFLAG_UNMAPPED_BIO) != 0)
484 		pp->flags |= G_PF_ACCEPT_UNMAPPED;
485 	if (bootverbose)
486 		printf("GEOM: new disk %s\n", gp->name);
487 	sysctl_ctx_init(&sc->sysctl_ctx);
488 	snprintf(tmpstr, sizeof(tmpstr), "GEOM disk %s", gp->name);
489 	sc->sysctl_tree = SYSCTL_ADD_NODE(&sc->sysctl_ctx,
490 		SYSCTL_STATIC_CHILDREN(_kern_geom_disk), OID_AUTO, gp->name,
491 		CTLFLAG_RD, 0, tmpstr);
492 	if (sc->sysctl_tree != NULL) {
493 		snprintf(tmpstr, sizeof(tmpstr),
494 		    "kern.geom.disk.%s.led", gp->name);
495 		TUNABLE_STR_FETCH(tmpstr, sc->led, sizeof(sc->led));
496 		SYSCTL_ADD_STRING(&sc->sysctl_ctx,
497 		    SYSCTL_CHILDREN(sc->sysctl_tree), OID_AUTO, "led",
498 		    CTLFLAG_RW | CTLFLAG_TUN, sc->led, sizeof(sc->led),
499 		    "LED name");
500 	}
501 	pp->private = sc;
502 	dp->d_geom = gp;
503 	g_error_provider(pp, 0);
504 }
505 
506 /*
507  * We get this callback after all of the consumers have gone away, and just
508  * before the provider is freed.  If the disk driver provided a d_gone
509  * callback, let them know that it is okay to free resources -- they won't
510  * be getting any more accesses from GEOM.
511  */
512 static void
513 g_disk_providergone(struct g_provider *pp)
514 {
515 	struct disk *dp;
516 	struct g_disk_softc *sc;
517 
518 	sc = (struct g_disk_softc *)pp->private;
519 	dp = sc->dp;
520 	if (dp != NULL && dp->d_gone != NULL)
521 		dp->d_gone(dp);
522 	if (sc->sysctl_tree != NULL) {
523 		sysctl_ctx_free(&sc->sysctl_ctx);
524 		sc->sysctl_tree = NULL;
525 	}
526 	if (sc->led[0] != 0) {
527 		led_set(sc->led, "0");
528 		sc->led[0] = 0;
529 	}
530 	pp->private = NULL;
531 	pp->geom->softc = NULL;
532 	mtx_destroy(&sc->done_mtx);
533 	g_free(sc);
534 }
535 
536 static void
537 g_disk_destroy(void *ptr, int flag)
538 {
539 	struct disk *dp;
540 	struct g_geom *gp;
541 	struct g_disk_softc *sc;
542 
543 	g_topology_assert();
544 	dp = ptr;
545 	gp = dp->d_geom;
546 	if (gp != NULL) {
547 		sc = gp->softc;
548 		if (sc != NULL)
549 			sc->dp = NULL;
550 		dp->d_geom = NULL;
551 		g_wither_geom(gp, ENXIO);
552 	}
553 	g_free(dp);
554 }
555 
556 /*
557  * We only allow printable characters in disk ident,
558  * the rest is converted to 'x<HH>'.
559  */
560 static void
561 g_disk_ident_adjust(char *ident, size_t size)
562 {
563 	char *p, tmp[4], newid[DISK_IDENT_SIZE];
564 
565 	newid[0] = '\0';
566 	for (p = ident; *p != '\0'; p++) {
567 		if (isprint(*p)) {
568 			tmp[0] = *p;
569 			tmp[1] = '\0';
570 		} else {
571 			snprintf(tmp, sizeof(tmp), "x%02hhx",
572 			    *(unsigned char *)p);
573 		}
574 		if (strlcat(newid, tmp, sizeof(newid)) >= sizeof(newid))
575 			break;
576 	}
577 	bzero(ident, size);
578 	strlcpy(ident, newid, size);
579 }
580 
581 struct disk *
582 disk_alloc(void)
583 {
584 
585 	return (g_malloc(sizeof(struct disk), M_WAITOK | M_ZERO));
586 }
587 
588 void
589 disk_create(struct disk *dp, int version)
590 {
591 
592 	if (version != DISK_VERSION_02) {
593 		printf("WARNING: Attempt to add disk %s%d %s",
594 		    dp->d_name, dp->d_unit,
595 		    " using incompatible ABI version of disk(9)\n");
596 		printf("WARNING: Ignoring disk %s%d\n",
597 		    dp->d_name, dp->d_unit);
598 		return;
599 	}
600 	KASSERT(dp->d_strategy != NULL, ("disk_create need d_strategy"));
601 	KASSERT(dp->d_name != NULL, ("disk_create need d_name"));
602 	KASSERT(*dp->d_name != 0, ("disk_create need d_name"));
603 	KASSERT(strlen(dp->d_name) < SPECNAMELEN - 4, ("disk name too long"));
604 	if (dp->d_devstat == NULL)
605 		dp->d_devstat = devstat_new_entry(dp->d_name, dp->d_unit,
606 		    dp->d_sectorsize, DEVSTAT_ALL_SUPPORTED,
607 		    DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
608 	dp->d_geom = NULL;
609 	g_disk_ident_adjust(dp->d_ident, sizeof(dp->d_ident));
610 	g_post_event(g_disk_create, dp, M_WAITOK, dp, NULL);
611 }
612 
613 void
614 disk_destroy(struct disk *dp)
615 {
616 
617 	g_cancel_event(dp);
618 	dp->d_destroyed = 1;
619 	if (dp->d_devstat != NULL)
620 		devstat_remove_entry(dp->d_devstat);
621 	g_post_event(g_disk_destroy, dp, M_WAITOK, NULL);
622 }
623 
624 void
625 disk_gone(struct disk *dp)
626 {
627 	struct g_geom *gp;
628 	struct g_provider *pp;
629 
630 	gp = dp->d_geom;
631 	if (gp != NULL) {
632 		pp = LIST_FIRST(&gp->provider);
633 		if (pp != NULL) {
634 			KASSERT(LIST_NEXT(pp, provider) == NULL,
635 			    ("geom %p has more than one provider", gp));
636 			g_wither_provider(pp, ENXIO);
637 		}
638 	}
639 }
640 
641 void
642 disk_attr_changed(struct disk *dp, const char *attr, int flag)
643 {
644 	struct g_geom *gp;
645 	struct g_provider *pp;
646 
647 	gp = dp->d_geom;
648 	if (gp != NULL)
649 		LIST_FOREACH(pp, &gp->provider, provider)
650 			(void)g_attr_changed(pp, attr, flag);
651 }
652 
653 void
654 disk_media_changed(struct disk *dp, int flag)
655 {
656 	struct g_geom *gp;
657 	struct g_provider *pp;
658 
659 	gp = dp->d_geom;
660 	if (gp != NULL) {
661 		pp = LIST_FIRST(&gp->provider);
662 		if (pp != NULL) {
663 			KASSERT(LIST_NEXT(pp, provider) == NULL,
664 			    ("geom %p has more than one provider", gp));
665 			g_media_changed(pp, flag);
666 		}
667 	}
668 }
669 
670 void
671 disk_media_gone(struct disk *dp, int flag)
672 {
673 	struct g_geom *gp;
674 	struct g_provider *pp;
675 
676 	gp = dp->d_geom;
677 	if (gp != NULL) {
678 		pp = LIST_FIRST(&gp->provider);
679 		if (pp != NULL) {
680 			KASSERT(LIST_NEXT(pp, provider) == NULL,
681 			    ("geom %p has more than one provider", gp));
682 			g_media_gone(pp, flag);
683 		}
684 	}
685 }
686 
687 int
688 disk_resize(struct disk *dp, int flag)
689 {
690 
691 	if (dp->d_destroyed || dp->d_geom == NULL)
692 		return (0);
693 
694 	return (g_post_event(g_disk_resize, dp, flag, NULL));
695 }
696 
697 static void
698 g_kern_disks(void *p, int flag __unused)
699 {
700 	struct sbuf *sb;
701 	struct g_geom *gp;
702 	char *sp;
703 
704 	sb = p;
705 	sp = "";
706 	g_topology_assert();
707 	LIST_FOREACH(gp, &g_disk_class.geom, geom) {
708 		sbuf_printf(sb, "%s%s", sp, gp->name);
709 		sp = " ";
710 	}
711 	sbuf_finish(sb);
712 }
713 
714 static int
715 sysctl_disks(SYSCTL_HANDLER_ARGS)
716 {
717 	int error;
718 	struct sbuf *sb;
719 
720 	sb = sbuf_new_auto();
721 	g_waitfor_event(g_kern_disks, sb, M_WAITOK, NULL);
722 	error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
723 	sbuf_delete(sb);
724 	return error;
725 }
726 
727 SYSCTL_PROC(_kern, OID_AUTO, disks,
728     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
729     sysctl_disks, "A", "names of available disks");
730