xref: /freebsd/sys/geom/geom_dev.c (revision fcb560670601b2a4d87bb31d7531c8dcc37ee71b)
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 <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/malloc.h>
42 #include <sys/kernel.h>
43 #include <sys/conf.h>
44 #include <sys/ctype.h>
45 #include <sys/bio.h>
46 #include <sys/bus.h>
47 #include <sys/lock.h>
48 #include <sys/mutex.h>
49 #include <sys/proc.h>
50 #include <sys/errno.h>
51 #include <sys/time.h>
52 #include <sys/disk.h>
53 #include <sys/fcntl.h>
54 #include <sys/limits.h>
55 #include <sys/sysctl.h>
56 #include <geom/geom.h>
57 #include <geom/geom_int.h>
58 #include <machine/stdarg.h>
59 
60 struct g_dev_softc {
61 	struct mtx	 sc_mtx;
62 	struct cdev	*sc_dev;
63 	struct cdev	*sc_alias;
64 	int		 sc_open;
65 	int		 sc_active;
66 };
67 
68 static d_open_t		g_dev_open;
69 static d_close_t	g_dev_close;
70 static d_strategy_t	g_dev_strategy;
71 static d_ioctl_t	g_dev_ioctl;
72 
73 static struct cdevsw g_dev_cdevsw = {
74 	.d_version =	D_VERSION,
75 	.d_open =	g_dev_open,
76 	.d_close =	g_dev_close,
77 	.d_read =	physread,
78 	.d_write =	physwrite,
79 	.d_ioctl =	g_dev_ioctl,
80 	.d_strategy =	g_dev_strategy,
81 	.d_name =	"g_dev",
82 	.d_flags =	D_DISK | D_TRACKCLOSE,
83 };
84 
85 static g_init_t g_dev_init;
86 static g_fini_t g_dev_fini;
87 static g_taste_t g_dev_taste;
88 static g_orphan_t g_dev_orphan;
89 static g_attrchanged_t g_dev_attrchanged;
90 
91 static struct g_class g_dev_class	= {
92 	.name = "DEV",
93 	.version = G_VERSION,
94 	.init = g_dev_init,
95 	.fini = g_dev_fini,
96 	.taste = g_dev_taste,
97 	.orphan = g_dev_orphan,
98 	.attrchanged = g_dev_attrchanged
99 };
100 
101 /*
102  * We target 262144 (8 x 32768) sectors by default as this significantly
103  * increases the throughput on commonly used SSD's with a marginal
104  * increase in non-interruptible request latency.
105  */
106 static uint64_t g_dev_del_max_sectors = 262144;
107 SYSCTL_DECL(_kern_geom);
108 SYSCTL_NODE(_kern_geom, OID_AUTO, dev, CTLFLAG_RW, 0, "GEOM_DEV stuff");
109 SYSCTL_QUAD(_kern_geom_dev, OID_AUTO, delete_max_sectors, CTLFLAG_RW,
110     &g_dev_del_max_sectors, 0, "Maximum number of sectors in a single "
111     "delete request sent to the provider. Larger requests are chunked "
112     "so they can be interrupted. (0 = disable chunking)");
113 
114 static char *dumpdev = NULL;
115 static void
116 g_dev_init(struct g_class *mp)
117 {
118 
119 	dumpdev = kern_getenv("dumpdev");
120 }
121 
122 static void
123 g_dev_fini(struct g_class *mp)
124 {
125 
126 	freeenv(dumpdev);
127 }
128 
129 static int
130 g_dev_setdumpdev(struct cdev *dev, struct thread *td)
131 {
132 	struct g_kerneldump kd;
133 	struct g_consumer *cp;
134 	int error, len;
135 
136 	if (dev == NULL)
137 		return (set_dumper(NULL, NULL, td));
138 
139 	cp = dev->si_drv2;
140 	len = sizeof(kd);
141 	kd.offset = 0;
142 	kd.length = OFF_MAX;
143 	error = g_io_getattr("GEOM::kerneldump", cp, &len, &kd);
144 	if (error == 0) {
145 		error = set_dumper(&kd.di, devtoname(dev), td);
146 		if (error == 0)
147 			dev->si_flags |= SI_DUMPDEV;
148 	}
149 	return (error);
150 }
151 
152 static void
153 init_dumpdev(struct cdev *dev)
154 {
155 
156 	if (dumpdev == NULL)
157 		return;
158 	if (strcmp(devtoname(dev), dumpdev) != 0)
159 		return;
160 	if (g_dev_setdumpdev(dev, curthread) == 0) {
161 		freeenv(dumpdev);
162 		dumpdev = NULL;
163 	}
164 }
165 
166 static void
167 g_dev_destroy(void *arg, int flags __unused)
168 {
169 	struct g_consumer *cp;
170 	struct g_geom *gp;
171 	struct g_dev_softc *sc;
172 	char buf[SPECNAMELEN + 6];
173 
174 	g_topology_assert();
175 	cp = arg;
176 	gp = cp->geom;
177 	sc = cp->private;
178 	g_trace(G_T_TOPOLOGY, "g_dev_destroy(%p(%s))", cp, gp->name);
179 	snprintf(buf, sizeof(buf), "cdev=%s", gp->name);
180 	devctl_notify_f("GEOM", "DEV", "DESTROY", buf, M_WAITOK);
181 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
182 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
183 	g_detach(cp);
184 	g_destroy_consumer(cp);
185 	g_destroy_geom(gp);
186 	mtx_destroy(&sc->sc_mtx);
187 	g_free(sc);
188 }
189 
190 void
191 g_dev_print(void)
192 {
193 	struct g_geom *gp;
194 	char const *p = "";
195 
196 	LIST_FOREACH(gp, &g_dev_class.geom, geom) {
197 		printf("%s%s", p, gp->name);
198 		p = " ";
199 	}
200 	printf("\n");
201 }
202 
203 static void
204 g_dev_attrchanged(struct g_consumer *cp, const char *attr)
205 {
206 	struct g_dev_softc *sc;
207 	struct cdev *dev;
208 	char buf[SPECNAMELEN + 6];
209 
210 	sc = cp->private;
211 	if (strcmp(attr, "GEOM::media") == 0) {
212 		dev = sc->sc_dev;
213 		snprintf(buf, sizeof(buf), "cdev=%s", dev->si_name);
214 		devctl_notify_f("DEVFS", "CDEV", "MEDIACHANGE", buf, M_WAITOK);
215 		devctl_notify_f("GEOM", "DEV", "MEDIACHANGE", buf, M_WAITOK);
216 		dev = sc->sc_alias;
217 		if (dev != NULL) {
218 			snprintf(buf, sizeof(buf), "cdev=%s", dev->si_name);
219 			devctl_notify_f("DEVFS", "CDEV", "MEDIACHANGE", buf,
220 			    M_WAITOK);
221 			devctl_notify_f("GEOM", "DEV", "MEDIACHANGE", buf,
222 			    M_WAITOK);
223 		}
224 		return;
225 	}
226 
227 	if (strcmp(attr, "GEOM::physpath") != 0)
228 		return;
229 
230 	if (g_access(cp, 1, 0, 0) == 0) {
231 		char *physpath;
232 		int error, physpath_len;
233 
234 		physpath_len = MAXPATHLEN;
235 		physpath = g_malloc(physpath_len, M_WAITOK|M_ZERO);
236 		error =
237 		    g_io_getattr("GEOM::physpath", cp, &physpath_len, physpath);
238 		g_access(cp, -1, 0, 0);
239 		if (error == 0 && strlen(physpath) != 0) {
240 			struct cdev *old_alias_dev;
241 			struct cdev **alias_devp;
242 
243 			dev = sc->sc_dev;
244 			old_alias_dev = sc->sc_alias;
245 			alias_devp = (struct cdev **)&sc->sc_alias;
246 			make_dev_physpath_alias(MAKEDEV_WAITOK, alias_devp,
247 			    dev, old_alias_dev, physpath);
248 		} else if (sc->sc_alias) {
249 			destroy_dev((struct cdev *)sc->sc_alias);
250 			sc->sc_alias = NULL;
251 		}
252 		g_free(physpath);
253 	}
254 }
255 
256 struct g_provider *
257 g_dev_getprovider(struct cdev *dev)
258 {
259 	struct g_consumer *cp;
260 
261 	g_topology_assert();
262 	if (dev == NULL)
263 		return (NULL);
264 	if (dev->si_devsw != &g_dev_cdevsw)
265 		return (NULL);
266 	cp = dev->si_drv2;
267 	return (cp->provider);
268 }
269 
270 static struct g_geom *
271 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
272 {
273 	struct g_geom *gp;
274 	struct g_consumer *cp;
275 	struct g_dev_softc *sc;
276 	int error, len;
277 	struct cdev *dev, *adev;
278 	char buf[SPECNAMELEN + 6], *val;
279 
280 	g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
281 	g_topology_assert();
282 	gp = g_new_geomf(mp, "%s", pp->name);
283 	sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
284 	mtx_init(&sc->sc_mtx, "g_dev", NULL, MTX_DEF);
285 	cp = g_new_consumer(gp);
286 	cp->private = sc;
287 	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
288 	error = g_attach(cp, pp);
289 	KASSERT(error == 0,
290 	    ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
291 	error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &dev,
292 	    &g_dev_cdevsw, NULL, UID_ROOT, GID_OPERATOR, 0640, "%s", gp->name);
293 	if (error != 0) {
294 		printf("%s: make_dev_p() failed (gp->name=%s, error=%d)\n",
295 		    __func__, gp->name, error);
296 		g_detach(cp);
297 		g_destroy_consumer(cp);
298 		g_destroy_geom(gp);
299 		mtx_destroy(&sc->sc_mtx);
300 		g_free(sc);
301 		return (NULL);
302 	}
303 	dev->si_flags |= SI_UNMAPPED;
304 	sc->sc_dev = dev;
305 
306 	/* Search for device alias name and create it if found. */
307 	adev = NULL;
308 	for (len = MIN(strlen(gp->name), sizeof(buf) - 15); len > 0; len--) {
309 		snprintf(buf, sizeof(buf), "kern.devalias.%s", gp->name);
310 		buf[14 + len] = 0;
311 		val = kern_getenv(buf);
312 		if (val != NULL) {
313 			snprintf(buf, sizeof(buf), "%s%s",
314 			    val, gp->name + len);
315 			freeenv(val);
316 			if ((make_dev_alias_p(MAKEDEV_CHECKNAME|MAKEDEV_WAITOK,
317 			    &adev, dev, "%s", buf)) != 0)
318 				printf("Warning: unable to create device "
319 				    "alias %s\n", buf);
320 			break;
321 		}
322 	}
323 
324 	dev->si_iosize_max = MAXPHYS;
325 	dev->si_drv2 = cp;
326 	init_dumpdev(dev);
327 	if (adev != NULL) {
328 		adev->si_iosize_max = MAXPHYS;
329 		adev->si_drv2 = cp;
330 		adev->si_flags |= SI_UNMAPPED;
331 		init_dumpdev(adev);
332 	}
333 
334 	g_dev_attrchanged(cp, "GEOM::physpath");
335 	snprintf(buf, sizeof(buf), "cdev=%s", gp->name);
336 	devctl_notify_f("GEOM", "DEV", "CREATE", buf, M_WAITOK);
337 
338 	return (gp);
339 }
340 
341 static int
342 g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
343 {
344 	struct g_consumer *cp;
345 	struct g_dev_softc *sc;
346 	int error, r, w, e;
347 
348 	cp = dev->si_drv2;
349 	if (cp == NULL)
350 		return (ENXIO);		/* g_dev_taste() not done yet */
351 	g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
352 	    cp->geom->name, flags, fmt, td);
353 
354 	r = flags & FREAD ? 1 : 0;
355 	w = flags & FWRITE ? 1 : 0;
356 #ifdef notyet
357 	e = flags & O_EXCL ? 1 : 0;
358 #else
359 	e = 0;
360 #endif
361 	if (w) {
362 		/*
363 		 * When running in very secure mode, do not allow
364 		 * opens for writing of any disks.
365 		 */
366 		error = securelevel_ge(td->td_ucred, 2);
367 		if (error)
368 			return (error);
369 	}
370 	g_topology_lock();
371 	error = g_access(cp, r, w, e);
372 	g_topology_unlock();
373 	if (error == 0) {
374 		sc = cp->private;
375 		mtx_lock(&sc->sc_mtx);
376 		if (sc->sc_open == 0 && sc->sc_active != 0)
377 			wakeup(&sc->sc_active);
378 		sc->sc_open += r + w + e;
379 		mtx_unlock(&sc->sc_mtx);
380 	}
381 	return (error);
382 }
383 
384 static int
385 g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
386 {
387 	struct g_consumer *cp;
388 	struct g_dev_softc *sc;
389 	int error, r, w, e;
390 
391 	cp = dev->si_drv2;
392 	if (cp == NULL)
393 		return (ENXIO);
394 	g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
395 	    cp->geom->name, flags, fmt, td);
396 
397 	r = flags & FREAD ? -1 : 0;
398 	w = flags & FWRITE ? -1 : 0;
399 #ifdef notyet
400 	e = flags & O_EXCL ? -1 : 0;
401 #else
402 	e = 0;
403 #endif
404 	sc = cp->private;
405 	mtx_lock(&sc->sc_mtx);
406 	sc->sc_open += r + w + e;
407 	while (sc->sc_open == 0 && sc->sc_active != 0)
408 		msleep(&sc->sc_active, &sc->sc_mtx, 0, "PRIBIO", 0);
409 	mtx_unlock(&sc->sc_mtx);
410 	g_topology_lock();
411 	error = g_access(cp, r, w, e);
412 	g_topology_unlock();
413 	return (error);
414 }
415 
416 /*
417  * XXX: Until we have unmessed the ioctl situation, there is a race against
418  * XXX: a concurrent orphanization.  We cannot close it by holding topology
419  * XXX: since that would prevent us from doing our job, and stalling events
420  * XXX: will break (actually: stall) the BSD disklabel hacks.
421  */
422 static int
423 g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
424 {
425 	struct g_consumer *cp;
426 	struct g_provider *pp;
427 	off_t offset, length, chunk;
428 	int i, error;
429 
430 	cp = dev->si_drv2;
431 	pp = cp->provider;
432 
433 	error = 0;
434 	KASSERT(cp->acr || cp->acw,
435 	    ("Consumer with zero access count in g_dev_ioctl"));
436 
437 	i = IOCPARM_LEN(cmd);
438 	switch (cmd) {
439 	case DIOCGSECTORSIZE:
440 		*(u_int *)data = cp->provider->sectorsize;
441 		if (*(u_int *)data == 0)
442 			error = ENOENT;
443 		break;
444 	case DIOCGMEDIASIZE:
445 		*(off_t *)data = cp->provider->mediasize;
446 		if (*(off_t *)data == 0)
447 			error = ENOENT;
448 		break;
449 	case DIOCGFWSECTORS:
450 		error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
451 		if (error == 0 && *(u_int *)data == 0)
452 			error = ENOENT;
453 		break;
454 	case DIOCGFWHEADS:
455 		error = g_io_getattr("GEOM::fwheads", cp, &i, data);
456 		if (error == 0 && *(u_int *)data == 0)
457 			error = ENOENT;
458 		break;
459 	case DIOCGFRONTSTUFF:
460 		error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
461 		break;
462 	case DIOCSKERNELDUMP:
463 		if (*(u_int *)data == 0)
464 			error = g_dev_setdumpdev(NULL, td);
465 		else
466 			error = g_dev_setdumpdev(dev, td);
467 		break;
468 	case DIOCGFLUSH:
469 		error = g_io_flush(cp);
470 		break;
471 	case DIOCGDELETE:
472 		offset = ((off_t *)data)[0];
473 		length = ((off_t *)data)[1];
474 		if ((offset % cp->provider->sectorsize) != 0 ||
475 		    (length % cp->provider->sectorsize) != 0 || length <= 0) {
476 			printf("%s: offset=%jd length=%jd\n", __func__, offset,
477 			    length);
478 			error = EINVAL;
479 			break;
480 		}
481 		while (length > 0) {
482 			chunk = length;
483 			if (g_dev_del_max_sectors != 0 && chunk >
484 			    g_dev_del_max_sectors * cp->provider->sectorsize) {
485 				chunk = g_dev_del_max_sectors *
486 				    cp->provider->sectorsize;
487 			}
488 			error = g_delete_data(cp, offset, chunk);
489 			length -= chunk;
490 			offset += chunk;
491 			if (error)
492 				break;
493 			/*
494 			 * Since the request size can be large, the service
495 			 * time can be is likewise.  We make this ioctl
496 			 * interruptible by checking for signals for each bio.
497 			 */
498 			if (SIGPENDING(td))
499 				break;
500 		}
501 		break;
502 	case DIOCGIDENT:
503 		error = g_io_getattr("GEOM::ident", cp, &i, data);
504 		break;
505 	case DIOCGPROVIDERNAME:
506 		if (pp == NULL)
507 			return (ENOENT);
508 		strlcpy(data, pp->name, i);
509 		break;
510 	case DIOCGSTRIPESIZE:
511 		*(off_t *)data = cp->provider->stripesize;
512 		break;
513 	case DIOCGSTRIPEOFFSET:
514 		*(off_t *)data = cp->provider->stripeoffset;
515 		break;
516 	case DIOCGPHYSPATH:
517 		error = g_io_getattr("GEOM::physpath", cp, &i, data);
518 		if (error == 0 && *(char *)data == '\0')
519 			error = ENOENT;
520 		break;
521 	case DIOCGATTR: {
522 		struct diocgattr_arg *arg = (struct diocgattr_arg *)data;
523 
524 		if (arg->len > sizeof(arg->value)) {
525 			error = EINVAL;
526 			break;
527 		}
528 		error = g_io_getattr(arg->name, cp, &arg->len, &arg->value);
529 		break;
530 	}
531 	default:
532 		if (cp->provider->geom->ioctl != NULL) {
533 			error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
534 		} else {
535 			error = ENOIOCTL;
536 		}
537 	}
538 
539 	return (error);
540 }
541 
542 static void
543 g_dev_done(struct bio *bp2)
544 {
545 	struct g_consumer *cp;
546 	struct g_dev_softc *sc;
547 	struct bio *bp;
548 	int destroy;
549 
550 	cp = bp2->bio_from;
551 	sc = cp->private;
552 	bp = bp2->bio_parent;
553 	bp->bio_error = bp2->bio_error;
554 	bp->bio_completed = bp2->bio_completed;
555 	bp->bio_resid = bp->bio_length - bp2->bio_completed;
556 	if (bp2->bio_error != 0) {
557 		g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
558 		    bp2, bp2->bio_error);
559 		bp->bio_flags |= BIO_ERROR;
560 	} else {
561 		g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
562 		    bp2, bp, bp2->bio_resid, (intmax_t)bp2->bio_completed);
563 	}
564 	g_destroy_bio(bp2);
565 	destroy = 0;
566 	mtx_lock(&sc->sc_mtx);
567 	if ((--sc->sc_active) == 0) {
568 		if (sc->sc_open == 0)
569 			wakeup(&sc->sc_active);
570 		if (sc->sc_dev == NULL)
571 			destroy = 1;
572 	}
573 	mtx_unlock(&sc->sc_mtx);
574 	if (destroy)
575 		g_post_event(g_dev_destroy, cp, M_WAITOK, NULL);
576 	biodone(bp);
577 }
578 
579 static void
580 g_dev_strategy(struct bio *bp)
581 {
582 	struct g_consumer *cp;
583 	struct bio *bp2;
584 	struct cdev *dev;
585 	struct g_dev_softc *sc;
586 
587 	KASSERT(bp->bio_cmd == BIO_READ ||
588 	        bp->bio_cmd == BIO_WRITE ||
589 	        bp->bio_cmd == BIO_DELETE ||
590 		bp->bio_cmd == BIO_FLUSH,
591 		("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
592 	dev = bp->bio_dev;
593 	cp = dev->si_drv2;
594 	sc = cp->private;
595 	KASSERT(cp->acr || cp->acw,
596 	    ("Consumer with zero access count in g_dev_strategy"));
597 #ifdef INVARIANTS
598 	if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
599 	    (bp->bio_bcount % cp->provider->sectorsize) != 0) {
600 		bp->bio_resid = bp->bio_bcount;
601 		biofinish(bp, NULL, EINVAL);
602 		return;
603 	}
604 #endif
605 	mtx_lock(&sc->sc_mtx);
606 	KASSERT(sc->sc_open > 0, ("Closed device in g_dev_strategy"));
607 	sc->sc_active++;
608 	mtx_unlock(&sc->sc_mtx);
609 
610 	for (;;) {
611 		/*
612 		 * XXX: This is not an ideal solution, but I belive it to
613 		 * XXX: deadlock safe, all things considered.
614 		 */
615 		bp2 = g_clone_bio(bp);
616 		if (bp2 != NULL)
617 			break;
618 		pause("gdstrat", hz / 10);
619 	}
620 	KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
621 	bp2->bio_done = g_dev_done;
622 	g_trace(G_T_BIO,
623 	    "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
624 	    bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
625 	    bp2->bio_data, bp2->bio_cmd);
626 	g_io_request(bp2, cp);
627 	KASSERT(cp->acr || cp->acw,
628 	    ("g_dev_strategy raced with g_dev_close and lost"));
629 
630 }
631 
632 /*
633  * g_dev_callback()
634  *
635  * Called by devfs when asynchronous device destruction is completed.
636  * - Mark that we have no attached device any more.
637  * - If there are no outstanding requests, schedule geom destruction.
638  *   Otherwise destruction will be scheduled later by g_dev_done().
639  */
640 
641 static void
642 g_dev_callback(void *arg)
643 {
644 	struct g_consumer *cp;
645 	struct g_dev_softc *sc;
646 	int destroy;
647 
648 	cp = arg;
649 	sc = cp->private;
650 	g_trace(G_T_TOPOLOGY, "g_dev_callback(%p(%s))", cp, cp->geom->name);
651 
652 	mtx_lock(&sc->sc_mtx);
653 	sc->sc_dev = NULL;
654 	sc->sc_alias = NULL;
655 	destroy = (sc->sc_active == 0);
656 	mtx_unlock(&sc->sc_mtx);
657 	if (destroy)
658 		g_post_event(g_dev_destroy, cp, M_WAITOK, NULL);
659 }
660 
661 /*
662  * g_dev_orphan()
663  *
664  * Called from below when the provider orphaned us.
665  * - Clear any dump settings.
666  * - Request asynchronous device destruction to prevent any more requests
667  *   from coming in.  The provider is already marked with an error, so
668  *   anything which comes in in the interrim will be returned immediately.
669  */
670 
671 static void
672 g_dev_orphan(struct g_consumer *cp)
673 {
674 	struct cdev *dev;
675 	struct g_dev_softc *sc;
676 
677 	g_topology_assert();
678 	sc = cp->private;
679 	dev = sc->sc_dev;
680 	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, cp->geom->name);
681 
682 	/* Reset any dump-area set on this device */
683 	if (dev->si_flags & SI_DUMPDEV)
684 		(void)set_dumper(NULL, NULL, curthread);
685 
686 	/* Destroy the struct cdev *so we get no more requests */
687 	destroy_dev_sched_cb(dev, g_dev_callback, cp);
688 }
689 
690 DECLARE_GEOM_CLASS(g_dev_class, g_dev);
691