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