xref: /freebsd/sys/geom/mountver/g_mountver.c (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2010 Edward Tomasz Napierala <trasz@FreeBSD.org>
5  * Copyright (c) 2004-2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 #include <sys/lock.h>
38 #include <sys/mutex.h>
39 #include <sys/bio.h>
40 #include <sys/disk.h>
41 #include <sys/proc.h>
42 #include <sys/sbuf.h>
43 #include <sys/sysctl.h>
44 #include <sys/malloc.h>
45 #include <sys/eventhandler.h>
46 #include <geom/geom.h>
47 #include <geom/geom_dbg.h>
48 #include <geom/mountver/g_mountver.h>
49 
50 SYSCTL_DECL(_kern_geom);
51 static SYSCTL_NODE(_kern_geom, OID_AUTO, mountver, CTLFLAG_RW | CTLFLAG_MPSAFE,
52     0, "GEOM_MOUNTVER stuff");
53 static u_int g_mountver_debug = 0;
54 static u_int g_mountver_check_ident = 1;
55 SYSCTL_UINT(_kern_geom_mountver, OID_AUTO, debug, CTLFLAG_RW,
56     &g_mountver_debug, 0, "Debug level");
57 SYSCTL_UINT(_kern_geom_mountver, OID_AUTO, check_ident, CTLFLAG_RW,
58     &g_mountver_check_ident, 0, "Check disk ident when reattaching");
59 
60 static eventhandler_tag g_mountver_pre_sync = NULL;
61 
62 static void g_mountver_queue(struct bio *bp);
63 static void g_mountver_orphan(struct g_consumer *cp);
64 static void g_mountver_resize(struct g_consumer *cp);
65 static int g_mountver_destroy(struct g_geom *gp, boolean_t force);
66 static g_taste_t g_mountver_taste;
67 static int g_mountver_destroy_geom(struct gctl_req *req, struct g_class *mp,
68     struct g_geom *gp);
69 static void g_mountver_config(struct gctl_req *req, struct g_class *mp,
70     const char *verb);
71 static void g_mountver_dumpconf(struct sbuf *sb, const char *indent,
72     struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp);
73 static void g_mountver_init(struct g_class *mp);
74 static void g_mountver_fini(struct g_class *mp);
75 
76 struct g_class g_mountver_class = {
77 	.name = G_MOUNTVER_CLASS_NAME,
78 	.version = G_VERSION,
79 	.ctlreq = g_mountver_config,
80 	.taste = g_mountver_taste,
81 	.destroy_geom = g_mountver_destroy_geom,
82 	.init = g_mountver_init,
83 	.fini = g_mountver_fini
84 };
85 
86 static void
87 g_mountver_detach(void *arg, int flags __unused)
88 {
89 	struct g_consumer *cp = arg;
90 
91 	g_topology_assert();
92 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
93 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
94 	g_detach(cp);
95 }
96 
97 static void
98 g_mountver_done(struct bio *bp)
99 {
100 	struct g_mountver_softc *sc;
101 	struct g_geom *gp;
102 	struct g_consumer *cp;
103 	struct bio *pbp;
104 
105 	cp = bp->bio_from;
106 	gp = cp->geom;
107 	if (bp->bio_error != ENXIO) {
108 		g_std_done(bp);
109 		goto done;
110 	}
111 
112 	/*
113 	 * When the device goes away, it's possible that few requests
114 	 * will be completed with ENXIO before g_mountver_orphan()
115 	 * gets called.  To work around that, we have to queue requests
116 	 * that failed with ENXIO, in order to send them later.
117 	 */
118 	pbp = bp->bio_parent;
119 	KASSERT(pbp->bio_to == LIST_FIRST(&gp->provider),
120 	    ("parent request was for someone else"));
121 	g_destroy_bio(bp);
122 	pbp->bio_inbed++;
123 	g_mountver_queue(pbp);
124 
125 done:
126 	sc = gp->softc;
127 	mtx_lock(&sc->sc_mtx);
128 	if (--cp->index == 0 && sc->sc_orphaned)
129 		g_post_event(g_mountver_detach, cp, M_NOWAIT, NULL);
130 	mtx_unlock(&sc->sc_mtx);
131 }
132 
133 /*
134  * Send the BIO down.  The function is called with sc_mtx held to cover
135  * the race with orphan, but drops it before external calls.
136  */
137 static void
138 g_mountver_send(struct g_geom *gp, struct bio *bp)
139 {
140 	struct g_mountver_softc *sc = gp->softc;
141 	struct g_consumer *cp;
142 	struct bio *cbp;
143 
144 	mtx_assert(&sc->sc_mtx, MA_OWNED);
145 	cbp = g_clone_bio(bp);
146 	if (cbp == NULL) {
147 		mtx_unlock(&sc->sc_mtx);
148 		g_io_deliver(bp, ENOMEM);
149 		return;
150 	}
151 	cp = LIST_FIRST(&gp->consumer);
152 	cp->index++;
153 	mtx_unlock(&sc->sc_mtx);
154 
155 	cbp->bio_done = g_mountver_done;
156 	g_io_request(cbp, cp);
157 }
158 
159 static void
160 g_mountver_queue(struct bio *bp)
161 {
162 	struct g_mountver_softc *sc;
163 	struct g_geom *gp;
164 
165 	gp = bp->bio_to->geom;
166 	sc = gp->softc;
167 
168 	mtx_lock(&sc->sc_mtx);
169 	TAILQ_INSERT_TAIL(&sc->sc_queue, bp, bio_queue);
170 	mtx_unlock(&sc->sc_mtx);
171 }
172 
173 static void
174 g_mountver_send_queued(struct g_geom *gp)
175 {
176 	struct g_mountver_softc *sc;
177 	struct bio *bp;
178 
179 	sc = gp->softc;
180 
181 	mtx_lock(&sc->sc_mtx);
182 	while ((bp = TAILQ_FIRST(&sc->sc_queue)) != NULL && !sc->sc_orphaned) {
183 		TAILQ_REMOVE(&sc->sc_queue, bp, bio_queue);
184 		G_MOUNTVER_LOGREQ(bp, "Sending queued request.");
185 		/* sc_mtx is dropped inside */
186 		g_mountver_send(gp, bp);
187 		mtx_lock(&sc->sc_mtx);
188 	}
189 	mtx_unlock(&sc->sc_mtx);
190 }
191 
192 static void
193 g_mountver_discard_queued(struct g_geom *gp)
194 {
195 	struct g_mountver_softc *sc;
196 	struct bio *bp;
197 
198 	sc = gp->softc;
199 
200 	mtx_lock(&sc->sc_mtx);
201 	while ((bp = TAILQ_FIRST(&sc->sc_queue)) != NULL) {
202 		TAILQ_REMOVE(&sc->sc_queue, bp, bio_queue);
203 		mtx_unlock(&sc->sc_mtx);
204 		G_MOUNTVER_LOGREQ(bp, "Discarding queued request.");
205 		g_io_deliver(bp, ENXIO);
206 		mtx_lock(&sc->sc_mtx);
207 	}
208 	mtx_unlock(&sc->sc_mtx);
209 }
210 
211 static void
212 g_mountver_start(struct bio *bp)
213 {
214 	struct g_mountver_softc *sc;
215 	struct g_geom *gp;
216 
217 	gp = bp->bio_to->geom;
218 	sc = gp->softc;
219 	G_MOUNTVER_LOGREQ(bp, "Request received.");
220 
221 	/*
222 	 * It is possible that some bios were returned with ENXIO, even though
223 	 * orphaning didn't happen yet.  In that case, queue all subsequent
224 	 * requests in order to maintain ordering.
225 	 */
226 	mtx_lock(&sc->sc_mtx);
227 	if (sc->sc_orphaned || !TAILQ_EMPTY(&sc->sc_queue)) {
228 		mtx_unlock(&sc->sc_mtx);
229 		if (sc->sc_shutting_down) {
230 			G_MOUNTVER_LOGREQ(bp, "Discarding request due to shutdown.");
231 			g_io_deliver(bp, ENXIO);
232 			return;
233 		}
234 		G_MOUNTVER_LOGREQ(bp, "Queueing request.");
235 		g_mountver_queue(bp);
236 		if (!sc->sc_orphaned)
237 			g_mountver_send_queued(gp);
238 	} else {
239 		G_MOUNTVER_LOGREQ(bp, "Sending request.");
240 		/* sc_mtx is dropped inside */
241 		g_mountver_send(gp, bp);
242 	}
243 }
244 
245 static int
246 g_mountver_access(struct g_provider *pp, int dr, int dw, int de)
247 {
248 	struct g_mountver_softc *sc;
249 	struct g_geom *gp;
250 	struct g_consumer *cp;
251 
252 	g_topology_assert();
253 
254 	gp = pp->geom;
255 	cp = LIST_FIRST(&gp->consumer);
256 	sc = gp->softc;
257 	if (sc == NULL && dr <= 0 && dw <= 0 && de <= 0)
258 		return (0);
259 	KASSERT(sc != NULL, ("Trying to access withered provider \"%s\".", pp->name));
260 
261 	sc->sc_access_r += dr;
262 	sc->sc_access_w += dw;
263 	sc->sc_access_e += de;
264 
265 	if (sc->sc_orphaned)
266 		return (0);
267 
268 	return (g_access(cp, dr, dw, de));
269 }
270 
271 static int
272 g_mountver_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp)
273 {
274 	struct g_mountver_softc *sc;
275 	struct g_geom *gp;
276 	struct g_provider *newpp;
277 	struct g_consumer *cp;
278 	struct g_geom_alias *gap;
279 	char name[64];
280 	int error;
281 	int identsize = DISK_IDENT_SIZE;
282 
283 	g_topology_assert();
284 
285 	gp = NULL;
286 	newpp = NULL;
287 	cp = NULL;
288 
289 	snprintf(name, sizeof(name), "%s%s", pp->name, G_MOUNTVER_SUFFIX);
290 	LIST_FOREACH(gp, &mp->geom, geom) {
291 		if (strcmp(gp->name, name) == 0) {
292 			gctl_error(req, "Provider %s already exists.", name);
293 			return (EEXIST);
294 		}
295 	}
296 	gp = g_new_geomf(mp, "%s", name);
297 	sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
298 	mtx_init(&sc->sc_mtx, "gmountver", NULL, MTX_DEF | MTX_RECURSE);
299 	TAILQ_INIT(&sc->sc_queue);
300 	sc->sc_provider_name = strdup(pp->name, M_GEOM);
301 	gp->softc = sc;
302 	gp->start = g_mountver_start;
303 	gp->orphan = g_mountver_orphan;
304 	gp->resize = g_mountver_resize;
305 	gp->access = g_mountver_access;
306 	gp->dumpconf = g_mountver_dumpconf;
307 
308 	newpp = g_new_providerf(gp, "%s", gp->name);
309 	newpp->mediasize = pp->mediasize;
310 	newpp->sectorsize = pp->sectorsize;
311 	newpp->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE;
312 	LIST_FOREACH(gap, &pp->aliases, ga_next)
313 		g_provider_add_alias(newpp, "%s%s", gap->ga_alias, G_MOUNTVER_SUFFIX);
314 
315 	if ((pp->flags & G_PF_ACCEPT_UNMAPPED) != 0) {
316 		G_MOUNTVER_DEBUG(0, "Unmapped supported for %s.", gp->name);
317 		newpp->flags |= G_PF_ACCEPT_UNMAPPED;
318 	} else {
319 		G_MOUNTVER_DEBUG(0, "Unmapped unsupported for %s.", gp->name);
320 		newpp->flags &= ~G_PF_ACCEPT_UNMAPPED;
321 	}
322 
323 	cp = g_new_consumer(gp);
324 	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
325 	error = g_attach(cp, pp);
326 	if (error != 0) {
327 		gctl_error(req, "Cannot attach to provider %s.", pp->name);
328 		goto fail;
329 	}
330 	error = g_access(cp, 1, 0, 0);
331 	if (error != 0) {
332 		gctl_error(req, "Cannot access provider %s.", pp->name);
333 		goto fail;
334 	}
335 	error = g_io_getattr("GEOM::ident", cp, &identsize, sc->sc_ident);
336 	g_access(cp, -1, 0, 0);
337 	if (error != 0) {
338 		if (g_mountver_check_ident) {
339 			gctl_error(req, "Cannot get disk ident from %s; error = %d.", pp->name, error);
340 			goto fail;
341 		}
342 
343 		G_MOUNTVER_DEBUG(0, "Cannot get disk ident from %s; error = %d.", pp->name, error);
344 		sc->sc_ident[0] = '\0';
345 	}
346 
347 	g_error_provider(newpp, 0);
348 	G_MOUNTVER_DEBUG(0, "Device %s created.", gp->name);
349 	return (0);
350 fail:
351 	g_free(sc->sc_provider_name);
352 	if (cp->provider != NULL)
353 		g_detach(cp);
354 	g_destroy_consumer(cp);
355 	g_destroy_provider(newpp);
356 	g_free(gp->softc);
357 	g_destroy_geom(gp);
358 	return (error);
359 }
360 
361 static int
362 g_mountver_destroy(struct g_geom *gp, boolean_t force)
363 {
364 	struct g_mountver_softc *sc;
365 	struct g_provider *pp;
366 
367 	g_topology_assert();
368 	if (gp->softc == NULL)
369 		return (ENXIO);
370 	sc = gp->softc;
371 	pp = LIST_FIRST(&gp->provider);
372 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
373 		if (force) {
374 			G_MOUNTVER_DEBUG(0, "Device %s is still open, so it "
375 			    "can't be definitely removed.", pp->name);
376 		} else {
377 			G_MOUNTVER_DEBUG(1, "Device %s is still open (r%dw%de%d).",
378 			    pp->name, pp->acr, pp->acw, pp->ace);
379 			return (EBUSY);
380 		}
381 	} else {
382 		G_MOUNTVER_DEBUG(0, "Device %s removed.", gp->name);
383 	}
384 	if (pp != NULL)
385 		g_wither_provider(pp, ENXIO);
386 	g_mountver_discard_queued(gp);
387 	g_free(sc->sc_provider_name);
388 	g_free(gp->softc);
389 	gp->softc = NULL;
390 	g_wither_geom(gp, ENXIO);
391 
392 	return (0);
393 }
394 
395 static int
396 g_mountver_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp)
397 {
398 
399 	return (g_mountver_destroy(gp, 0));
400 }
401 
402 static void
403 g_mountver_ctl_create(struct gctl_req *req, struct g_class *mp)
404 {
405 	struct g_provider *pp;
406 	char param[16];
407 	int i, *nargs;
408 
409 	g_topology_assert();
410 
411 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
412 	if (nargs == NULL) {
413 		gctl_error(req, "No '%s' argument", "nargs");
414 		return;
415 	}
416 	if (*nargs <= 0) {
417 		gctl_error(req, "Missing device(s).");
418 		return;
419 	}
420 	for (i = 0; i < *nargs; i++) {
421 		snprintf(param, sizeof(param), "arg%d", i);
422 		pp = gctl_get_provider(req, param);
423 		if (pp == NULL)
424 			return;
425 		if (g_mountver_create(req, mp, pp) != 0)
426 			return;
427 	}
428 }
429 
430 static struct g_geom *
431 g_mountver_find_geom(struct g_class *mp, const char *name)
432 {
433 	struct g_geom *gp;
434 
435 	LIST_FOREACH(gp, &mp->geom, geom) {
436 		if (strcmp(gp->name, name) == 0)
437 			return (gp);
438 	}
439 	return (NULL);
440 }
441 
442 static void
443 g_mountver_ctl_destroy(struct gctl_req *req, struct g_class *mp)
444 {
445 	int *nargs, *force, error, i;
446 	struct g_geom *gp;
447 	const char *name;
448 	char param[16];
449 
450 	g_topology_assert();
451 
452 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
453 	if (nargs == NULL) {
454 		gctl_error(req, "No '%s' argument", "nargs");
455 		return;
456 	}
457 	if (*nargs <= 0) {
458 		gctl_error(req, "Missing device(s).");
459 		return;
460 	}
461 	force = gctl_get_paraml(req, "force", sizeof(*force));
462 	if (force == NULL) {
463 		gctl_error(req, "No 'force' argument");
464 		return;
465 	}
466 
467 	for (i = 0; i < *nargs; i++) {
468 		snprintf(param, sizeof(param), "arg%d", i);
469 		name = gctl_get_asciiparam(req, param);
470 		if (name == NULL) {
471 			gctl_error(req, "No 'arg%d' argument", i);
472 			return;
473 		}
474 		if (strncmp(name, _PATH_DEV, strlen(_PATH_DEV)) == 0)
475 			name += strlen(_PATH_DEV);
476 		gp = g_mountver_find_geom(mp, name);
477 		if (gp == NULL) {
478 			G_MOUNTVER_DEBUG(1, "Device %s is invalid.", name);
479 			gctl_error(req, "Device %s is invalid.", name);
480 			return;
481 		}
482 		error = g_mountver_destroy(gp, *force);
483 		if (error != 0) {
484 			gctl_error(req, "Cannot destroy device %s (error=%d).",
485 			    gp->name, error);
486 			return;
487 		}
488 	}
489 }
490 
491 static void
492 g_mountver_orphan(struct g_consumer *cp)
493 {
494 	struct g_mountver_softc *sc;
495 	int done;
496 
497 	g_topology_assert();
498 
499 	sc = cp->geom->softc;
500 	mtx_lock(&sc->sc_mtx);
501 	sc->sc_orphaned = 1;
502 	done = (cp->index == 0);
503 	mtx_unlock(&sc->sc_mtx);
504 	if (done)
505 		g_mountver_detach(cp, 0);
506 	G_MOUNTVER_DEBUG(0, "%s is offline.  Mount verification in progress.", sc->sc_provider_name);
507 }
508 
509 static void
510 g_mountver_resize(struct g_consumer *cp)
511 {
512 	struct g_geom *gp;
513 	struct g_provider *pp;
514 
515 	gp = cp->geom;
516 
517 	LIST_FOREACH(pp, &gp->provider, provider)
518 		g_resize_provider(pp, cp->provider->mediasize);
519 }
520 
521 static int
522 g_mountver_ident_matches(struct g_geom *gp)
523 {
524 	struct g_consumer *cp;
525 	struct g_mountver_softc *sc;
526 	char ident[DISK_IDENT_SIZE];
527 	int error, identsize = DISK_IDENT_SIZE;
528 
529 	sc = gp->softc;
530 	cp = LIST_FIRST(&gp->consumer);
531 
532 	if (g_mountver_check_ident == 0)
533 		return (0);
534 
535 	error = g_access(cp, 1, 0, 0);
536 	if (error != 0) {
537 		G_MOUNTVER_DEBUG(0, "Cannot access %s; "
538 		    "not attaching; error = %d.", gp->name, error);
539 		return (1);
540 	}
541 	error = g_io_getattr("GEOM::ident", cp, &identsize, ident);
542 	g_access(cp, -1, 0, 0);
543 	if (error != 0) {
544 		G_MOUNTVER_DEBUG(0, "Cannot get disk ident for %s; "
545 		    "not attaching; error = %d.", gp->name, error);
546 		return (1);
547 	}
548 	if (strcmp(ident, sc->sc_ident) != 0) {
549 		G_MOUNTVER_DEBUG(1, "Disk ident for %s (\"%s\") is different "
550 		    "from expected \"%s\", not attaching.", gp->name, ident,
551 		    sc->sc_ident);
552 		return (1);
553 	}
554 
555 	return (0);
556 }
557 
558 static struct g_geom *
559 g_mountver_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
560 {
561 	struct g_mountver_softc *sc;
562 	struct g_consumer *cp;
563 	struct g_geom *gp;
564 	int error;
565 
566 	g_topology_assert();
567 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
568 	G_MOUNTVER_DEBUG(2, "Tasting %s.", pp->name);
569 
570 	/*
571 	 * Let's check if device already exists.
572 	 */
573 	LIST_FOREACH(gp, &mp->geom, geom) {
574 		sc = gp->softc;
575 		if (sc == NULL)
576 			continue;
577 
578 		/* Already attached? */
579 		if (pp == LIST_FIRST(&gp->provider))
580 			return (NULL);
581 
582 		if (sc->sc_orphaned && strcmp(pp->name, sc->sc_provider_name) == 0)
583 			break;
584 	}
585 	if (gp == NULL)
586 		return (NULL);
587 
588 	cp = LIST_FIRST(&gp->consumer);
589 	error = g_attach(cp, pp);
590 	if (error != 0) {
591 		G_MOUNTVER_DEBUG(0, "Cannot attach to %s; error = %d.", pp->name, error);
592 		return (NULL);
593 	}
594 
595 	error = g_mountver_ident_matches(gp);
596 	if (error != 0) {
597 		g_detach(cp);
598 		return (NULL);
599 	}
600 	if (sc->sc_access_r > 0 || sc->sc_access_w > 0 || sc->sc_access_e > 0) {
601 		error = g_access(cp, sc->sc_access_r, sc->sc_access_w, sc->sc_access_e);
602 		if (error != 0) {
603 			G_MOUNTVER_DEBUG(0, "Cannot access %s; error = %d.", pp->name, error);
604 			g_detach(cp);
605 			return (NULL);
606 		}
607 	}
608 	sc->sc_orphaned = 0;
609 	g_mountver_send_queued(gp);
610 	G_MOUNTVER_DEBUG(0, "%s has completed mount verification.", sc->sc_provider_name);
611 
612 	return (gp);
613 }
614 
615 static void
616 g_mountver_config(struct gctl_req *req, struct g_class *mp, const char *verb)
617 {
618 	uint32_t *version;
619 
620 	g_topology_assert();
621 
622 	version = gctl_get_paraml(req, "version", sizeof(*version));
623 	if (version == NULL) {
624 		gctl_error(req, "No '%s' argument.", "version");
625 		return;
626 	}
627 	if (*version != G_MOUNTVER_VERSION) {
628 		gctl_error(req, "Userland and kernel parts are out of sync.");
629 		return;
630 	}
631 
632 	if (strcmp(verb, "create") == 0) {
633 		g_mountver_ctl_create(req, mp);
634 		return;
635 	} else if (strcmp(verb, "destroy") == 0) {
636 		g_mountver_ctl_destroy(req, mp);
637 		return;
638 	}
639 
640 	gctl_error(req, "Unknown verb.");
641 }
642 
643 static void
644 g_mountver_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
645     struct g_consumer *cp, struct g_provider *pp)
646 {
647 	struct g_mountver_softc *sc;
648 
649 	if (pp != NULL || cp != NULL)
650 		return;
651 
652 	sc = gp->softc;
653 	sbuf_printf(sb, "%s<State>%s</State>\n", indent,
654 	    sc->sc_orphaned ? "OFFLINE" : "ONLINE");
655 	sbuf_printf(sb, "%s<Provider-Name>%s</Provider-Name>\n", indent, sc->sc_provider_name);
656 	sbuf_printf(sb, "%s<Disk-Ident>%s</Disk-Ident>\n", indent, sc->sc_ident);
657 }
658 
659 static void
660 g_mountver_shutdown_pre_sync(void *arg, int howto)
661 {
662 	struct g_mountver_softc *sc;
663 	struct g_class *mp;
664 	struct g_geom *gp, *gp2;
665 
666 	mp = arg;
667 	g_topology_lock();
668 	LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
669 		if (gp->softc == NULL)
670 			continue;
671 		sc = gp->softc;
672 		sc->sc_shutting_down = 1;
673 		if (sc->sc_orphaned)
674 			g_mountver_destroy(gp, 1);
675 	}
676 	g_topology_unlock();
677 }
678 
679 static void
680 g_mountver_init(struct g_class *mp)
681 {
682 
683 	g_mountver_pre_sync = EVENTHANDLER_REGISTER(shutdown_pre_sync,
684 	    g_mountver_shutdown_pre_sync, mp, SHUTDOWN_PRI_FIRST);
685 	if (g_mountver_pre_sync == NULL)
686 		G_MOUNTVER_DEBUG(0, "Warning! Cannot register shutdown event.");
687 }
688 
689 static void
690 g_mountver_fini(struct g_class *mp)
691 {
692 
693 	if (g_mountver_pre_sync != NULL)
694 		EVENTHANDLER_DEREGISTER(shutdown_pre_sync, g_mountver_pre_sync);
695 }
696 
697 DECLARE_GEOM_CLASS(g_mountver_class, g_mountver);
698 MODULE_VERSION(geom_mountver, 0);
699