xref: /freebsd/sys/geom/geom_dev.c (revision 3806950135d2c8633ec0764e8807eacc87cf3e10)
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_compat.h"
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/malloc.h>
44 #include <sys/kernel.h>
45 #include <sys/conf.h>
46 #include <sys/ctype.h>
47 #include <sys/bio.h>
48 #include <sys/bus.h>
49 #include <sys/lock.h>
50 #include <sys/mutex.h>
51 #include <sys/proc.h>
52 #include <sys/errno.h>
53 #include <sys/time.h>
54 #include <sys/disk.h>
55 #include <sys/fcntl.h>
56 #include <sys/limits.h>
57 #include <sys/sysctl.h>
58 #include <geom/geom.h>
59 #include <geom/geom_int.h>
60 #include <machine/stdarg.h>
61 
62 struct g_dev_softc {
63 	struct mtx	 sc_mtx;
64 	struct cdev	*sc_dev;
65 	struct cdev	*sc_alias;
66 	int		 sc_open;
67 	int		 sc_active;
68 };
69 
70 static d_open_t		g_dev_open;
71 static d_close_t	g_dev_close;
72 static d_strategy_t	g_dev_strategy;
73 static d_ioctl_t	g_dev_ioctl;
74 
75 static struct cdevsw g_dev_cdevsw = {
76 	.d_version =	D_VERSION,
77 	.d_open =	g_dev_open,
78 	.d_close =	g_dev_close,
79 	.d_read =	physread,
80 	.d_write =	physwrite,
81 	.d_ioctl =	g_dev_ioctl,
82 	.d_strategy =	g_dev_strategy,
83 	.d_name =	"g_dev",
84 	.d_flags =	D_DISK | D_TRACKCLOSE,
85 };
86 
87 static g_init_t g_dev_init;
88 static g_fini_t g_dev_fini;
89 static g_taste_t g_dev_taste;
90 static g_orphan_t g_dev_orphan;
91 static g_attrchanged_t g_dev_attrchanged;
92 
93 static struct g_class g_dev_class	= {
94 	.name = "DEV",
95 	.version = G_VERSION,
96 	.init = g_dev_init,
97 	.fini = g_dev_fini,
98 	.taste = g_dev_taste,
99 	.orphan = g_dev_orphan,
100 	.attrchanged = g_dev_attrchanged
101 };
102 
103 /*
104  * We target 262144 (8 x 32768) sectors by default as this significantly
105  * increases the throughput on commonly used SSD's with a marginal
106  * increase in non-interruptible request latency.
107  */
108 static uint64_t g_dev_del_max_sectors = 262144;
109 SYSCTL_DECL(_kern_geom);
110 SYSCTL_NODE(_kern_geom, OID_AUTO, dev, CTLFLAG_RW, 0, "GEOM_DEV stuff");
111 SYSCTL_QUAD(_kern_geom_dev, OID_AUTO, delete_max_sectors, CTLFLAG_RW,
112     &g_dev_del_max_sectors, 0, "Maximum number of sectors in a single "
113     "delete request sent to the provider. Larger requests are chunked "
114     "so they can be interrupted. (0 = disable chunking)");
115 
116 static char *dumpdev = NULL;
117 static void
118 g_dev_init(struct g_class *mp)
119 {
120 
121 	dumpdev = kern_getenv("dumpdev");
122 }
123 
124 static void
125 g_dev_fini(struct g_class *mp)
126 {
127 
128 	freeenv(dumpdev);
129 	dumpdev = NULL;
130 }
131 
132 static int
133 g_dev_setdumpdev(struct cdev *dev, struct diocskerneldump_arg *kda,
134     struct thread *td)
135 {
136 	struct g_kerneldump kd;
137 	struct g_consumer *cp;
138 	int error, len;
139 
140 	if (dev == NULL || kda == NULL)
141 		return (set_dumper(NULL, NULL, td, 0, 0, NULL, 0, NULL));
142 
143 	cp = dev->si_drv2;
144 	len = sizeof(kd);
145 	kd.offset = 0;
146 	kd.length = OFF_MAX;
147 	error = g_io_getattr("GEOM::kerneldump", cp, &len, &kd);
148 	if (error != 0)
149 		return (error);
150 
151 	error = set_dumper(&kd.di, devtoname(dev), td, kda->kda_compression,
152 	    kda->kda_encryption, kda->kda_key, kda->kda_encryptedkeysize,
153 	    kda->kda_encryptedkey);
154 	if (error == 0)
155 		dev->si_flags |= SI_DUMPDEV;
156 
157 	return (error);
158 }
159 
160 static int
161 init_dumpdev(struct cdev *dev)
162 {
163 	struct diocskerneldump_arg kda;
164 	struct g_consumer *cp;
165 	const char *devprefix = "/dev/", *devname;
166 	int error;
167 	size_t len;
168 
169 	bzero(&kda, sizeof(kda));
170 	kda.kda_enable = 1;
171 
172 	if (dumpdev == NULL)
173 		return (0);
174 
175 	len = strlen(devprefix);
176 	devname = devtoname(dev);
177 	if (strcmp(devname, dumpdev) != 0 &&
178 	   (strncmp(dumpdev, devprefix, len) != 0 ||
179 	    strcmp(devname, dumpdev + len) != 0))
180 		return (0);
181 
182 	cp = (struct g_consumer *)dev->si_drv2;
183 	error = g_access(cp, 1, 0, 0);
184 	if (error != 0)
185 		return (error);
186 
187 	error = g_dev_setdumpdev(dev, &kda, curthread);
188 	if (error == 0) {
189 		freeenv(dumpdev);
190 		dumpdev = NULL;
191 	}
192 
193 	(void)g_access(cp, -1, 0, 0);
194 
195 	return (error);
196 }
197 
198 static void
199 g_dev_destroy(void *arg, int flags __unused)
200 {
201 	struct g_consumer *cp;
202 	struct g_geom *gp;
203 	struct g_dev_softc *sc;
204 	char buf[SPECNAMELEN + 6];
205 
206 	g_topology_assert();
207 	cp = arg;
208 	gp = cp->geom;
209 	sc = cp->private;
210 	g_trace(G_T_TOPOLOGY, "g_dev_destroy(%p(%s))", cp, gp->name);
211 	snprintf(buf, sizeof(buf), "cdev=%s", gp->name);
212 	devctl_notify_f("GEOM", "DEV", "DESTROY", buf, M_WAITOK);
213 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
214 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
215 	g_detach(cp);
216 	g_destroy_consumer(cp);
217 	g_destroy_geom(gp);
218 	mtx_destroy(&sc->sc_mtx);
219 	g_free(sc);
220 }
221 
222 void
223 g_dev_print(void)
224 {
225 	struct g_geom *gp;
226 	char const *p = "";
227 
228 	LIST_FOREACH(gp, &g_dev_class.geom, geom) {
229 		printf("%s%s", p, gp->name);
230 		p = " ";
231 	}
232 	printf("\n");
233 }
234 
235 static void
236 g_dev_set_physpath(struct g_consumer *cp)
237 {
238 	struct g_dev_softc *sc;
239 	char *physpath;
240 	int error, physpath_len;
241 
242 	if (g_access(cp, 1, 0, 0) != 0)
243 		return;
244 
245 	sc = cp->private;
246 	physpath_len = MAXPATHLEN;
247 	physpath = g_malloc(physpath_len, M_WAITOK|M_ZERO);
248 	error = g_io_getattr("GEOM::physpath", cp, &physpath_len, physpath);
249 	g_access(cp, -1, 0, 0);
250 	if (error == 0 && strlen(physpath) != 0) {
251 		struct cdev *dev, *old_alias_dev;
252 		struct cdev **alias_devp;
253 
254 		dev = sc->sc_dev;
255 		old_alias_dev = sc->sc_alias;
256 		alias_devp = (struct cdev **)&sc->sc_alias;
257 		make_dev_physpath_alias(MAKEDEV_WAITOK, alias_devp, dev,
258 		    old_alias_dev, physpath);
259 	} else if (sc->sc_alias) {
260 		destroy_dev((struct cdev *)sc->sc_alias);
261 		sc->sc_alias = NULL;
262 	}
263 	g_free(physpath);
264 }
265 
266 static void
267 g_dev_set_media(struct g_consumer *cp)
268 {
269 	struct g_dev_softc *sc;
270 	struct cdev *dev;
271 	char buf[SPECNAMELEN + 6];
272 
273 	sc = cp->private;
274 	dev = sc->sc_dev;
275 	snprintf(buf, sizeof(buf), "cdev=%s", dev->si_name);
276 	devctl_notify_f("DEVFS", "CDEV", "MEDIACHANGE", buf, M_WAITOK);
277 	devctl_notify_f("GEOM", "DEV", "MEDIACHANGE", buf, M_WAITOK);
278 	dev = sc->sc_alias;
279 	if (dev != NULL) {
280 		snprintf(buf, sizeof(buf), "cdev=%s", dev->si_name);
281 		devctl_notify_f("DEVFS", "CDEV", "MEDIACHANGE", buf, M_WAITOK);
282 		devctl_notify_f("GEOM", "DEV", "MEDIACHANGE", buf, M_WAITOK);
283 	}
284 }
285 
286 static void
287 g_dev_attrchanged(struct g_consumer *cp, const char *attr)
288 {
289 
290 	if (strcmp(attr, "GEOM::media") == 0) {
291 		g_dev_set_media(cp);
292 		return;
293 	}
294 
295 	if (strcmp(attr, "GEOM::physpath") == 0) {
296 		g_dev_set_physpath(cp);
297 		return;
298 	}
299 }
300 
301 struct g_provider *
302 g_dev_getprovider(struct cdev *dev)
303 {
304 	struct g_consumer *cp;
305 
306 	g_topology_assert();
307 	if (dev == NULL)
308 		return (NULL);
309 	if (dev->si_devsw != &g_dev_cdevsw)
310 		return (NULL);
311 	cp = dev->si_drv2;
312 	return (cp->provider);
313 }
314 
315 static struct g_geom *
316 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
317 {
318 	struct g_geom *gp;
319 	struct g_geom_alias *gap;
320 	struct g_consumer *cp;
321 	struct g_dev_softc *sc;
322 	int error;
323 	struct cdev *dev, *adev;
324 	char buf[SPECNAMELEN + 6];
325 
326 	g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
327 	g_topology_assert();
328 	gp = g_new_geomf(mp, "%s", pp->name);
329 	sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
330 	mtx_init(&sc->sc_mtx, "g_dev", NULL, MTX_DEF);
331 	cp = g_new_consumer(gp);
332 	cp->private = sc;
333 	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
334 	error = g_attach(cp, pp);
335 	KASSERT(error == 0,
336 	    ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
337 	error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &dev,
338 	    &g_dev_cdevsw, NULL, UID_ROOT, GID_OPERATOR, 0640, "%s", gp->name);
339 	if (error != 0) {
340 		printf("%s: make_dev_p() failed (gp->name=%s, error=%d)\n",
341 		    __func__, gp->name, error);
342 		g_detach(cp);
343 		g_destroy_consumer(cp);
344 		g_destroy_geom(gp);
345 		mtx_destroy(&sc->sc_mtx);
346 		g_free(sc);
347 		return (NULL);
348 	}
349 	dev->si_flags |= SI_UNMAPPED;
350 	sc->sc_dev = dev;
351 
352 	dev->si_iosize_max = MAXPHYS;
353 	dev->si_drv2 = cp;
354 	error = init_dumpdev(dev);
355 	if (error != 0)
356 		printf("%s: init_dumpdev() failed (gp->name=%s, error=%d)\n",
357 		    __func__, gp->name, error);
358 
359 	g_dev_attrchanged(cp, "GEOM::physpath");
360 	snprintf(buf, sizeof(buf), "cdev=%s", gp->name);
361 	devctl_notify_f("GEOM", "DEV", "CREATE", buf, M_WAITOK);
362 	/*
363 	 * Now add all the aliases for this drive
364 	 */
365 	LIST_FOREACH(gap, &pp->geom->aliases, ga_next) {
366 		error = make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &adev, dev,
367 		    "%s", gap->ga_alias);
368 		if (error) {
369 			printf("%s: make_dev_alias_p() failed (name=%s, error=%d)\n",
370 			    __func__, gap->ga_alias, error);
371 			continue;
372 		}
373 		snprintf(buf, sizeof(buf), "cdev=%s", gap->ga_alias);
374 		devctl_notify_f("GEOM", "DEV", "CREATE", buf, M_WAITOK);
375 	}
376 
377 	return (gp);
378 }
379 
380 static int
381 g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
382 {
383 	struct g_consumer *cp;
384 	struct g_dev_softc *sc;
385 	int error, r, w, e;
386 
387 	cp = dev->si_drv2;
388 	if (cp == NULL)
389 		return (ENXIO);		/* g_dev_taste() not done yet */
390 	g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
391 	    cp->geom->name, flags, fmt, td);
392 
393 	r = flags & FREAD ? 1 : 0;
394 	w = flags & FWRITE ? 1 : 0;
395 #ifdef notyet
396 	e = flags & O_EXCL ? 1 : 0;
397 #else
398 	e = 0;
399 #endif
400 
401 	/*
402 	 * This happens on attempt to open a device node with O_EXEC.
403 	 */
404 	if (r + w + e == 0)
405 		return (EINVAL);
406 
407 	if (w) {
408 		/*
409 		 * When running in very secure mode, do not allow
410 		 * opens for writing of any disks.
411 		 */
412 		error = securelevel_ge(td->td_ucred, 2);
413 		if (error)
414 			return (error);
415 	}
416 	g_topology_lock();
417 	error = g_access(cp, r, w, e);
418 	g_topology_unlock();
419 	if (error == 0) {
420 		sc = cp->private;
421 		mtx_lock(&sc->sc_mtx);
422 		if (sc->sc_open == 0 && sc->sc_active != 0)
423 			wakeup(&sc->sc_active);
424 		sc->sc_open += r + w + e;
425 		mtx_unlock(&sc->sc_mtx);
426 	}
427 	return (error);
428 }
429 
430 static int
431 g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
432 {
433 	struct g_consumer *cp;
434 	struct g_dev_softc *sc;
435 	int error, r, w, e;
436 
437 	cp = dev->si_drv2;
438 	if (cp == NULL)
439 		return (ENXIO);
440 	g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
441 	    cp->geom->name, flags, fmt, td);
442 
443 	r = flags & FREAD ? -1 : 0;
444 	w = flags & FWRITE ? -1 : 0;
445 #ifdef notyet
446 	e = flags & O_EXCL ? -1 : 0;
447 #else
448 	e = 0;
449 #endif
450 
451 	/*
452 	 * The vgonel(9) - caused by eg. forced unmount of devfs - calls
453 	 * VOP_CLOSE(9) on devfs vnode without any FREAD or FWRITE flags,
454 	 * which would result in zero deltas, which in turn would cause
455 	 * panic in g_access(9).
456 	 *
457 	 * Note that we cannot zero the counters (ie. do "r = cp->acr"
458 	 * etc) instead, because the consumer might be opened in another
459 	 * devfs instance.
460 	 */
461 	if (r + w + e == 0)
462 		return (EINVAL);
463 
464 	sc = cp->private;
465 	mtx_lock(&sc->sc_mtx);
466 	sc->sc_open += r + w + e;
467 	while (sc->sc_open == 0 && sc->sc_active != 0)
468 		msleep(&sc->sc_active, &sc->sc_mtx, 0, "PRIBIO", 0);
469 	mtx_unlock(&sc->sc_mtx);
470 	g_topology_lock();
471 	error = g_access(cp, r, w, e);
472 	g_topology_unlock();
473 	return (error);
474 }
475 
476 /*
477  * XXX: Until we have unmessed the ioctl situation, there is a race against
478  * XXX: a concurrent orphanization.  We cannot close it by holding topology
479  * XXX: since that would prevent us from doing our job, and stalling events
480  * XXX: will break (actually: stall) the BSD disklabel hacks.
481  */
482 static int
483 g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
484 {
485 	struct g_consumer *cp;
486 	struct g_provider *pp;
487 	off_t offset, length, chunk, odd;
488 	int i, error;
489 
490 	cp = dev->si_drv2;
491 	pp = cp->provider;
492 
493 	error = 0;
494 	KASSERT(cp->acr || cp->acw,
495 	    ("Consumer with zero access count in g_dev_ioctl"));
496 
497 	i = IOCPARM_LEN(cmd);
498 	switch (cmd) {
499 	case DIOCGSECTORSIZE:
500 		*(u_int *)data = cp->provider->sectorsize;
501 		if (*(u_int *)data == 0)
502 			error = ENOENT;
503 		break;
504 	case DIOCGMEDIASIZE:
505 		*(off_t *)data = cp->provider->mediasize;
506 		if (*(off_t *)data == 0)
507 			error = ENOENT;
508 		break;
509 	case DIOCGFWSECTORS:
510 		error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
511 		if (error == 0 && *(u_int *)data == 0)
512 			error = ENOENT;
513 		break;
514 	case DIOCGFWHEADS:
515 		error = g_io_getattr("GEOM::fwheads", cp, &i, data);
516 		if (error == 0 && *(u_int *)data == 0)
517 			error = ENOENT;
518 		break;
519 	case DIOCGFRONTSTUFF:
520 		error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
521 		break;
522 #ifdef COMPAT_FREEBSD11
523 	case DIOCSKERNELDUMP_FREEBSD11:
524 	    {
525 		struct diocskerneldump_arg kda;
526 
527 		bzero(&kda, sizeof(kda));
528 		kda.kda_encryption = KERNELDUMP_ENC_NONE;
529 		kda.kda_enable = (uint8_t)*(u_int *)data;
530 		if (kda.kda_enable == 0)
531 			error = g_dev_setdumpdev(NULL, NULL, td);
532 		else
533 			error = g_dev_setdumpdev(dev, &kda, td);
534 		break;
535 	    }
536 #endif
537 	case DIOCSKERNELDUMP:
538 	    {
539 		struct diocskerneldump_arg *kda;
540 		uint8_t *encryptedkey;
541 
542 		kda = (struct diocskerneldump_arg *)data;
543 		if (kda->kda_enable == 0) {
544 			error = g_dev_setdumpdev(NULL, NULL, td);
545 			break;
546 		}
547 
548 		if (kda->kda_encryption != KERNELDUMP_ENC_NONE) {
549 			if (kda->kda_encryptedkeysize <= 0 ||
550 			    kda->kda_encryptedkeysize >
551 			    KERNELDUMP_ENCKEY_MAX_SIZE) {
552 				return (EINVAL);
553 			}
554 			encryptedkey = malloc(kda->kda_encryptedkeysize, M_TEMP,
555 			    M_WAITOK);
556 			error = copyin(kda->kda_encryptedkey, encryptedkey,
557 			    kda->kda_encryptedkeysize);
558 		} else {
559 			encryptedkey = NULL;
560 		}
561 		if (error == 0) {
562 			kda->kda_encryptedkey = encryptedkey;
563 			error = g_dev_setdumpdev(dev, kda, td);
564 		}
565 		if (encryptedkey != NULL) {
566 			explicit_bzero(encryptedkey, kda->kda_encryptedkeysize);
567 			free(encryptedkey, M_TEMP);
568 		}
569 		explicit_bzero(kda, sizeof(*kda));
570 		break;
571 	    }
572 	case DIOCGFLUSH:
573 		error = g_io_flush(cp);
574 		break;
575 	case DIOCGDELETE:
576 		offset = ((off_t *)data)[0];
577 		length = ((off_t *)data)[1];
578 		if ((offset % cp->provider->sectorsize) != 0 ||
579 		    (length % cp->provider->sectorsize) != 0 || length <= 0) {
580 			printf("%s: offset=%jd length=%jd\n", __func__, offset,
581 			    length);
582 			error = EINVAL;
583 			break;
584 		}
585 		while (length > 0) {
586 			chunk = length;
587 			if (g_dev_del_max_sectors != 0 && chunk >
588 			    g_dev_del_max_sectors * cp->provider->sectorsize) {
589 				chunk = g_dev_del_max_sectors *
590 				    cp->provider->sectorsize;
591 				if (cp->provider->stripesize > 0) {
592 					odd = (offset + chunk +
593 					    cp->provider->stripeoffset) %
594 					    cp->provider->stripesize;
595 					if (chunk > odd)
596 						chunk -= odd;
597 				}
598 			}
599 			error = g_delete_data(cp, offset, chunk);
600 			length -= chunk;
601 			offset += chunk;
602 			if (error)
603 				break;
604 			/*
605 			 * Since the request size can be large, the service
606 			 * time can be is likewise.  We make this ioctl
607 			 * interruptible by checking for signals for each bio.
608 			 */
609 			if (SIGPENDING(td))
610 				break;
611 		}
612 		break;
613 	case DIOCGIDENT:
614 		error = g_io_getattr("GEOM::ident", cp, &i, data);
615 		break;
616 	case DIOCGPROVIDERNAME:
617 		if (pp == NULL)
618 			return (ENOENT);
619 		strlcpy(data, pp->name, i);
620 		break;
621 	case DIOCGSTRIPESIZE:
622 		*(off_t *)data = cp->provider->stripesize;
623 		break;
624 	case DIOCGSTRIPEOFFSET:
625 		*(off_t *)data = cp->provider->stripeoffset;
626 		break;
627 	case DIOCGPHYSPATH:
628 		error = g_io_getattr("GEOM::physpath", cp, &i, data);
629 		if (error == 0 && *(char *)data == '\0')
630 			error = ENOENT;
631 		break;
632 	case DIOCGATTR: {
633 		struct diocgattr_arg *arg = (struct diocgattr_arg *)data;
634 
635 		if (arg->len > sizeof(arg->value)) {
636 			error = EINVAL;
637 			break;
638 		}
639 		error = g_io_getattr(arg->name, cp, &arg->len, &arg->value);
640 		break;
641 	}
642 	case DIOCZONECMD: {
643 		struct disk_zone_args *zone_args =(struct disk_zone_args *)data;
644 		struct disk_zone_rep_entry *new_entries, *old_entries;
645 		struct disk_zone_report *rep;
646 		size_t alloc_size;
647 
648 		old_entries = NULL;
649 		new_entries = NULL;
650 		rep = NULL;
651 		alloc_size = 0;
652 
653 		if (zone_args->zone_cmd == DISK_ZONE_REPORT_ZONES) {
654 
655 			rep = &zone_args->zone_params.report;
656 			alloc_size = rep->entries_allocated *
657 			    sizeof(struct disk_zone_rep_entry);
658 			if (alloc_size != 0)
659 				new_entries = g_malloc(alloc_size,
660 				    M_WAITOK| M_ZERO);
661 			old_entries = rep->entries;
662 			rep->entries = new_entries;
663 		}
664 		error = g_io_zonecmd(zone_args, cp);
665 		if ((zone_args->zone_cmd == DISK_ZONE_REPORT_ZONES)
666 		 && (alloc_size != 0)
667 		 && (error == 0)) {
668 			error = copyout(new_entries, old_entries, alloc_size);
669 		}
670 		if ((old_entries != NULL)
671 		 && (rep != NULL))
672 			rep->entries = old_entries;
673 
674 		if (new_entries != NULL)
675 			g_free(new_entries);
676 		break;
677 	}
678 	default:
679 		if (cp->provider->geom->ioctl != NULL) {
680 			error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
681 		} else {
682 			error = ENOIOCTL;
683 		}
684 	}
685 
686 	return (error);
687 }
688 
689 static void
690 g_dev_done(struct bio *bp2)
691 {
692 	struct g_consumer *cp;
693 	struct g_dev_softc *sc;
694 	struct bio *bp;
695 	int destroy;
696 
697 	cp = bp2->bio_from;
698 	sc = cp->private;
699 	bp = bp2->bio_parent;
700 	bp->bio_error = bp2->bio_error;
701 	bp->bio_completed = bp2->bio_completed;
702 	bp->bio_resid = bp->bio_length - bp2->bio_completed;
703 	if (bp2->bio_cmd == BIO_ZONE)
704 		bcopy(&bp2->bio_zone, &bp->bio_zone, sizeof(bp->bio_zone));
705 
706 	if (bp2->bio_error != 0) {
707 		g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
708 		    bp2, bp2->bio_error);
709 		bp->bio_flags |= BIO_ERROR;
710 	} else {
711 		g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
712 		    bp2, bp, bp2->bio_resid, (intmax_t)bp2->bio_completed);
713 	}
714 	g_destroy_bio(bp2);
715 	destroy = 0;
716 	mtx_lock(&sc->sc_mtx);
717 	if ((--sc->sc_active) == 0) {
718 		if (sc->sc_open == 0)
719 			wakeup(&sc->sc_active);
720 		if (sc->sc_dev == NULL)
721 			destroy = 1;
722 	}
723 	mtx_unlock(&sc->sc_mtx);
724 	if (destroy)
725 		g_post_event(g_dev_destroy, cp, M_NOWAIT, NULL);
726 	biodone(bp);
727 }
728 
729 static void
730 g_dev_strategy(struct bio *bp)
731 {
732 	struct g_consumer *cp;
733 	struct bio *bp2;
734 	struct cdev *dev;
735 	struct g_dev_softc *sc;
736 
737 	KASSERT(bp->bio_cmd == BIO_READ ||
738 	        bp->bio_cmd == BIO_WRITE ||
739 	        bp->bio_cmd == BIO_DELETE ||
740 		bp->bio_cmd == BIO_FLUSH ||
741 		bp->bio_cmd == BIO_ZONE,
742 		("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
743 	dev = bp->bio_dev;
744 	cp = dev->si_drv2;
745 	sc = cp->private;
746 	KASSERT(cp->acr || cp->acw,
747 	    ("Consumer with zero access count in g_dev_strategy"));
748 	biotrack(bp, __func__);
749 #ifdef INVARIANTS
750 	if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
751 	    (bp->bio_bcount % cp->provider->sectorsize) != 0) {
752 		bp->bio_resid = bp->bio_bcount;
753 		biofinish(bp, NULL, EINVAL);
754 		return;
755 	}
756 #endif
757 	mtx_lock(&sc->sc_mtx);
758 	KASSERT(sc->sc_open > 0, ("Closed device in g_dev_strategy"));
759 	sc->sc_active++;
760 	mtx_unlock(&sc->sc_mtx);
761 
762 	for (;;) {
763 		/*
764 		 * XXX: This is not an ideal solution, but I believe it to
765 		 * XXX: deadlock safely, all things considered.
766 		 */
767 		bp2 = g_clone_bio(bp);
768 		if (bp2 != NULL)
769 			break;
770 		pause("gdstrat", hz / 10);
771 	}
772 	KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
773 	bp2->bio_done = g_dev_done;
774 	g_trace(G_T_BIO,
775 	    "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
776 	    bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
777 	    bp2->bio_data, bp2->bio_cmd);
778 	g_io_request(bp2, cp);
779 	KASSERT(cp->acr || cp->acw,
780 	    ("g_dev_strategy raced with g_dev_close and lost"));
781 
782 }
783 
784 /*
785  * g_dev_callback()
786  *
787  * Called by devfs when asynchronous device destruction is completed.
788  * - Mark that we have no attached device any more.
789  * - If there are no outstanding requests, schedule geom destruction.
790  *   Otherwise destruction will be scheduled later by g_dev_done().
791  */
792 
793 static void
794 g_dev_callback(void *arg)
795 {
796 	struct g_consumer *cp;
797 	struct g_dev_softc *sc;
798 	int destroy;
799 
800 	cp = arg;
801 	sc = cp->private;
802 	g_trace(G_T_TOPOLOGY, "g_dev_callback(%p(%s))", cp, cp->geom->name);
803 
804 	mtx_lock(&sc->sc_mtx);
805 	sc->sc_dev = NULL;
806 	sc->sc_alias = NULL;
807 	destroy = (sc->sc_active == 0);
808 	mtx_unlock(&sc->sc_mtx);
809 	if (destroy)
810 		g_post_event(g_dev_destroy, cp, M_WAITOK, NULL);
811 }
812 
813 /*
814  * g_dev_orphan()
815  *
816  * Called from below when the provider orphaned us.
817  * - Clear any dump settings.
818  * - Request asynchronous device destruction to prevent any more requests
819  *   from coming in.  The provider is already marked with an error, so
820  *   anything which comes in the interim will be returned immediately.
821  */
822 
823 static void
824 g_dev_orphan(struct g_consumer *cp)
825 {
826 	struct cdev *dev;
827 	struct g_dev_softc *sc;
828 
829 	g_topology_assert();
830 	sc = cp->private;
831 	dev = sc->sc_dev;
832 	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, cp->geom->name);
833 
834 	/* Reset any dump-area set on this device */
835 	if (dev->si_flags & SI_DUMPDEV)
836 		(void)set_dumper(NULL, NULL, curthread, 0, 0, NULL, 0, NULL);
837 
838 	/* Destroy the struct cdev *so we get no more requests */
839 	destroy_dev_sched_cb(dev, g_dev_callback, cp);
840 }
841 
842 DECLARE_GEOM_CLASS(g_dev_class, g_dev);
843