g_gate.c revision 155174
1/*-
2 * Copyright (c) 2004-2005 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: head/sys/geom/gate/g_gate.c 155174 2006-02-01 12:06:01Z pjd $
27 */
28
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/bio.h>
32#include <sys/conf.h>
33#include <sys/kernel.h>
34#include <sys/kthread.h>
35#include <sys/fcntl.h>
36#include <sys/linker.h>
37#include <sys/lock.h>
38#include <sys/malloc.h>
39#include <sys/mutex.h>
40#include <sys/proc.h>
41#include <sys/limits.h>
42#include <sys/queue.h>
43#include <sys/sysctl.h>
44#include <sys/signalvar.h>
45#include <sys/time.h>
46#include <machine/atomic.h>
47
48#include <geom/geom.h>
49#include <geom/gate/g_gate.h>
50
51static MALLOC_DEFINE(M_GATE, "gg_data", "GEOM Gate Data");
52
53SYSCTL_DECL(_kern_geom);
54SYSCTL_NODE(_kern_geom, OID_AUTO, gate, CTLFLAG_RW, 0, "GEOM_GATE stuff");
55static u_int g_gate_debug = 0;
56SYSCTL_UINT(_kern_geom_gate, OID_AUTO, debug, CTLFLAG_RW, &g_gate_debug, 0,
57    "Debug level");
58
59static int g_gate_destroy_geom(struct gctl_req *, struct g_class *,
60    struct g_geom *);
61struct g_class g_gate_class = {
62	.name = G_GATE_CLASS_NAME,
63	.version = G_VERSION,
64	.destroy_geom = g_gate_destroy_geom
65};
66
67static struct cdev *status_dev;
68static d_ioctl_t g_gate_ioctl;
69static struct cdevsw g_gate_cdevsw = {
70	.d_version =	D_VERSION,
71	.d_ioctl =	g_gate_ioctl,
72	.d_name =	G_GATE_CTL_NAME
73};
74
75
76static LIST_HEAD(, g_gate_softc) g_gate_list =
77    LIST_HEAD_INITIALIZER(&g_gate_list);
78static struct mtx g_gate_list_mtx;
79
80
81static void
82g_gate_wither(struct g_gate_softc *sc)
83{
84
85	atomic_set_32(&sc->sc_flags, G_GATE_FLAG_DESTROY);
86}
87
88static int
89g_gate_destroy(struct g_gate_softc *sc, boolean_t force)
90{
91	struct g_provider *pp;
92	struct bio *bp;
93
94	g_topology_assert();
95	mtx_assert(&g_gate_list_mtx, MA_OWNED);
96	pp = sc->sc_provider;
97	if (!force && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
98		mtx_unlock(&g_gate_list_mtx);
99		return (EBUSY);
100	}
101	if ((sc->sc_flags & G_GATE_FLAG_DESTROY) == 0) {
102		g_gate_wither(sc);
103		LIST_REMOVE(sc, sc_next);
104	}
105	mtx_unlock(&g_gate_list_mtx);
106	mtx_lock(&sc->sc_queue_mtx);
107	wakeup(sc);
108	mtx_unlock(&sc->sc_queue_mtx);
109	if (sc->sc_ref > 0) {
110		G_GATE_DEBUG(1, "Cannot destroy %s yet.", sc->sc_name);
111		return (0);
112	}
113	callout_drain(&sc->sc_callout);
114	mtx_lock(&sc->sc_queue_mtx);
115	for (;;) {
116		bp = bioq_first(&sc->sc_inqueue);
117		if (bp != NULL) {
118			bioq_remove(&sc->sc_inqueue, bp);
119			sc->sc_queue_count--;
120			G_GATE_LOGREQ(1, bp, "Request canceled.");
121			g_io_deliver(bp, ENXIO);
122		} else {
123			break;
124		}
125	}
126	for (;;) {
127		bp = bioq_first(&sc->sc_outqueue);
128		if (bp != NULL) {
129			bioq_remove(&sc->sc_outqueue, bp);
130			sc->sc_queue_count--;
131			G_GATE_LOGREQ(1, bp, "Request canceled.");
132			g_io_deliver(bp, ENXIO);
133		} else {
134			break;
135		}
136	}
137	mtx_destroy(&sc->sc_queue_mtx);
138	G_GATE_DEBUG(0, "Device %s destroyed.", sc->sc_name);
139	pp->geom->softc = NULL;
140	g_wither_geom(pp->geom, ENXIO);
141	sc->sc_provider = NULL;
142	free(sc, M_GATE);
143	return (0);
144}
145
146static void
147g_gate_destroy_it(void *arg, int flag __unused)
148{
149	struct g_gate_softc *sc;
150
151	g_topology_assert();
152	sc = arg;
153	mtx_lock(&g_gate_list_mtx);
154	g_gate_destroy(sc, 1);
155}
156
157static int
158g_gate_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp)
159{
160
161	g_topology_assert();
162	mtx_lock(&g_gate_list_mtx);
163	return (g_gate_destroy(gp->softc, 0));
164}
165
166static int
167g_gate_access(struct g_provider *pp, int dr, int dw, int de)
168{
169	struct g_gate_softc *sc;
170
171	if (dr <= 0 && dw <= 0 && de <= 0)
172		return (0);
173	sc = pp->geom->softc;
174	if (sc == NULL || (sc->sc_flags & G_GATE_FLAG_DESTROY) != 0)
175		return (ENXIO);
176	/* XXX: Hack to allow read-only mounts. */
177#if 0
178	if ((sc->sc_flags & G_GATE_FLAG_READONLY) != 0 && dw > 0)
179		return (EPERM);
180#endif
181	if ((sc->sc_flags & G_GATE_FLAG_WRITEONLY) != 0 && dr > 0)
182		return (EPERM);
183	return (0);
184}
185
186static void
187g_gate_start(struct bio *bp)
188{
189	struct g_gate_softc *sc;
190
191	sc = bp->bio_to->geom->softc;
192	if (sc == NULL || (sc->sc_flags & G_GATE_FLAG_DESTROY) != 0) {
193		g_io_deliver(bp, ENXIO);
194		return;
195	}
196	G_GATE_LOGREQ(2, bp, "Request received.");
197	switch (bp->bio_cmd) {
198	case BIO_READ:
199		break;
200	case BIO_DELETE:
201	case BIO_WRITE:
202		/* XXX: Hack to allow read-only mounts. */
203		if ((sc->sc_flags & G_GATE_FLAG_READONLY) != 0) {
204			g_io_deliver(bp, EPERM);
205			return;
206		}
207		break;
208	case BIO_GETATTR:
209	default:
210		G_GATE_LOGREQ(2, bp, "Ignoring request.");
211		g_io_deliver(bp, EOPNOTSUPP);
212		return;
213	}
214
215	mtx_lock(&sc->sc_queue_mtx);
216	if (sc->sc_queue_count > sc->sc_queue_size) {
217		mtx_unlock(&sc->sc_queue_mtx);
218		G_GATE_LOGREQ(1, bp, "Queue full, request canceled.");
219		g_io_deliver(bp, EIO);
220		return;
221	}
222
223	bp->bio_driver1 = (void *)sc->sc_seq;
224	sc->sc_seq++;
225	sc->sc_queue_count++;
226
227	bioq_insert_tail(&sc->sc_inqueue, bp);
228	wakeup(sc);
229
230	mtx_unlock(&sc->sc_queue_mtx);
231}
232
233static struct g_gate_softc *
234g_gate_find(u_int unit)
235{
236	struct g_gate_softc *sc;
237
238	LIST_FOREACH(sc, &g_gate_list, sc_next) {
239		if (sc->sc_unit == unit)
240			break;
241	}
242	return (sc);
243}
244
245static struct g_gate_softc *
246g_gate_hold(u_int unit)
247{
248	struct g_gate_softc *sc;
249
250	mtx_lock(&g_gate_list_mtx);
251	sc = g_gate_find(unit);
252	if (sc != NULL) {
253		if ((sc->sc_flags & G_GATE_FLAG_DESTROY) != 0)
254			sc = NULL;
255		else
256			sc->sc_ref++;
257	}
258	mtx_unlock(&g_gate_list_mtx);
259	return (sc);
260}
261
262static void
263g_gate_release(struct g_gate_softc *sc)
264{
265
266	g_topology_assert_not();
267	mtx_lock(&g_gate_list_mtx);
268	sc->sc_ref--;
269	KASSERT(sc->sc_ref >= 0, ("Negative sc_ref for %s.", sc->sc_name));
270	if (sc->sc_ref == 0 && (sc->sc_flags & G_GATE_FLAG_DESTROY) != 0) {
271		mtx_unlock(&g_gate_list_mtx);
272		g_waitfor_event(g_gate_destroy_it, sc, M_WAITOK, NULL);
273	} else {
274		mtx_unlock(&g_gate_list_mtx);
275	}
276}
277
278static int
279g_gate_getunit(int unit)
280{
281	struct g_gate_softc *sc;
282
283	mtx_assert(&g_gate_list_mtx, MA_OWNED);
284	if (unit >= 0) {
285		LIST_FOREACH(sc, &g_gate_list, sc_next) {
286			if (sc->sc_unit == unit)
287				return (-1);
288		}
289	} else {
290		unit = 0;
291once_again:
292		LIST_FOREACH(sc, &g_gate_list, sc_next) {
293			if (sc->sc_unit == unit) {
294				if (++unit > 666)
295					return (-1);
296				goto once_again;
297			}
298		}
299	}
300	return (unit);
301}
302
303static void
304g_gate_guard(void *arg)
305{
306	struct g_gate_softc *sc;
307	struct bintime curtime;
308	struct bio *bp, *bp2;
309
310	sc = arg;
311	binuptime(&curtime);
312	g_gate_hold(sc->sc_unit);
313	mtx_lock(&sc->sc_queue_mtx);
314	TAILQ_FOREACH_SAFE(bp, &sc->sc_inqueue.queue, bio_queue, bp2) {
315		if (curtime.sec - bp->bio_t0.sec < 5)
316			continue;
317		bioq_remove(&sc->sc_inqueue, bp);
318		sc->sc_queue_count--;
319		G_GATE_LOGREQ(1, bp, "Request timeout.");
320		g_io_deliver(bp, EIO);
321	}
322	TAILQ_FOREACH_SAFE(bp, &sc->sc_outqueue.queue, bio_queue, bp2) {
323		if (curtime.sec - bp->bio_t0.sec < 5)
324			continue;
325		bioq_remove(&sc->sc_outqueue, bp);
326		sc->sc_queue_count--;
327		G_GATE_LOGREQ(1, bp, "Request timeout.");
328		g_io_deliver(bp, EIO);
329	}
330	mtx_unlock(&sc->sc_queue_mtx);
331	if ((sc->sc_flags & G_GATE_FLAG_DESTROY) == 0) {
332		callout_reset(&sc->sc_callout, sc->sc_timeout * hz,
333		    g_gate_guard, sc);
334	}
335	g_gate_release(sc);
336}
337
338static void
339g_gate_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
340    struct g_consumer *cp, struct g_provider *pp)
341{
342	struct g_gate_softc *sc;
343
344	sc = gp->softc;
345	if (sc == NULL || pp != NULL || cp != NULL)
346		return;
347	g_gate_hold(sc->sc_unit);
348	if ((sc->sc_flags & G_GATE_FLAG_READONLY) != 0) {
349		sbuf_printf(sb, "%s<access>%s</access>\n", indent, "read-only");
350	} else if ((sc->sc_flags & G_GATE_FLAG_WRITEONLY) != 0) {
351		sbuf_printf(sb, "%s<access>%s</access>\n", indent,
352		    "write-only");
353	} else {
354		sbuf_printf(sb, "%s<access>%s</access>\n", indent,
355		    "read-write");
356	}
357	sbuf_printf(sb, "%s<timeout>%u</timeout>\n", indent, sc->sc_timeout);
358	sbuf_printf(sb, "%s<info>%s</info>\n", indent, sc->sc_info);
359	sbuf_printf(sb, "%s<queue_count>%u</queue_count>\n", indent,
360	    sc->sc_queue_count);
361	sbuf_printf(sb, "%s<queue_size>%u</queue_size>\n", indent,
362	    sc->sc_queue_size);
363	sbuf_printf(sb, "%s<ref>%u</ref>\n", indent, sc->sc_ref);
364	g_topology_unlock();
365	g_gate_release(sc);
366	g_topology_lock();
367}
368
369static int
370g_gate_create(struct g_gate_ctl_create *ggio)
371{
372	struct g_gate_softc *sc;
373	struct g_geom *gp;
374	struct g_provider *pp;
375
376	if (ggio->gctl_mediasize == 0) {
377		G_GATE_DEBUG(1, "Invalid media size.");
378		return (EINVAL);
379	}
380	if (ggio->gctl_sectorsize > 0 && !powerof2(ggio->gctl_sectorsize)) {
381		G_GATE_DEBUG(1, "Invalid sector size.");
382		return (EINVAL);
383	}
384	if ((ggio->gctl_mediasize % ggio->gctl_sectorsize) != 0) {
385		G_GATE_DEBUG(1, "Invalid media size.");
386		return (EINVAL);
387	}
388	if ((ggio->gctl_flags & G_GATE_FLAG_READONLY) != 0 &&
389	    (ggio->gctl_flags & G_GATE_FLAG_WRITEONLY) != 0) {
390		G_GATE_DEBUG(1, "Invalid flags.");
391		return (EINVAL);
392	}
393	if (ggio->gctl_unit < -1) {
394		G_GATE_DEBUG(1, "Invalid unit number.");
395		return (EINVAL);
396	}
397
398	sc = malloc(sizeof(*sc), M_GATE, M_WAITOK | M_ZERO);
399	sc->sc_flags = (ggio->gctl_flags & G_GATE_USERFLAGS);
400	strlcpy(sc->sc_info, ggio->gctl_info, sizeof(sc->sc_info));
401	sc->sc_seq = 0;
402	bioq_init(&sc->sc_inqueue);
403	bioq_init(&sc->sc_outqueue);
404	mtx_init(&sc->sc_queue_mtx, "gg:queue", NULL, MTX_DEF);
405	sc->sc_queue_count = 0;
406	sc->sc_queue_size = ggio->gctl_maxcount;
407	if (sc->sc_queue_size > G_GATE_MAX_QUEUE_SIZE)
408		sc->sc_queue_size = G_GATE_MAX_QUEUE_SIZE;
409	sc->sc_timeout = ggio->gctl_timeout;
410	callout_init(&sc->sc_callout, CALLOUT_MPSAFE);
411	mtx_lock(&g_gate_list_mtx);
412	ggio->gctl_unit = g_gate_getunit(ggio->gctl_unit);
413	if (ggio->gctl_unit == -1) {
414		mtx_unlock(&g_gate_list_mtx);
415		mtx_destroy(&sc->sc_queue_mtx);
416		free(sc, M_GATE);
417		return (EBUSY);
418	}
419	sc->sc_unit = ggio->gctl_unit;
420	LIST_INSERT_HEAD(&g_gate_list, sc, sc_next);
421	mtx_unlock(&g_gate_list_mtx);
422
423	g_topology_lock();
424	gp = g_new_geomf(&g_gate_class, "%s%d", G_GATE_PROVIDER_NAME,
425	    sc->sc_unit);
426	gp->start = g_gate_start;
427	gp->access = g_gate_access;
428	gp->dumpconf = g_gate_dumpconf;
429	gp->softc = sc;
430	pp = g_new_providerf(gp, "%s%d", G_GATE_PROVIDER_NAME, sc->sc_unit);
431	pp->mediasize = ggio->gctl_mediasize;
432	pp->sectorsize = ggio->gctl_sectorsize;
433	sc->sc_provider = pp;
434	g_error_provider(pp, 0);
435	g_topology_unlock();
436
437	if (sc->sc_timeout > 0) {
438		callout_reset(&sc->sc_callout, sc->sc_timeout * hz,
439		    g_gate_guard, sc);
440	}
441	return (0);
442}
443
444#define	G_GATE_CHECK_VERSION(ggio)	do {				\
445	if ((ggio)->gctl_version != G_GATE_VERSION) {			\
446		printf("Version mismatch %d != %d.\n",			\
447		    ggio->gctl_version, G_GATE_VERSION);		\
448		return (EINVAL);					\
449	}								\
450} while (0)
451static int
452g_gate_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td)
453{
454	struct g_gate_softc *sc;
455	struct bio *bp;
456	int error = 0;
457
458	G_GATE_DEBUG(4, "ioctl(%s, %lx, %p, %x, %p)", devtoname(dev), cmd, addr,
459	    flags, td);
460
461	switch (cmd) {
462	case G_GATE_CMD_CREATE:
463	    {
464		struct g_gate_ctl_create *ggio = (void *)addr;
465
466		G_GATE_CHECK_VERSION(ggio);
467		error = g_gate_create(ggio);
468		/*
469		 * Reset TDP_GEOM flag.
470		 * There are pending events for sure, because we just created
471		 * new provider and other classes want to taste it, but we
472		 * cannot answer on I/O requests until we're here.
473		 */
474		td->td_pflags &= ~TDP_GEOM;
475		return (error);
476	    }
477	case G_GATE_CMD_DESTROY:
478	    {
479		struct g_gate_ctl_destroy *ggio = (void *)addr;
480
481		G_GATE_CHECK_VERSION(ggio);
482		sc = g_gate_hold(ggio->gctl_unit);
483		if (sc == NULL)
484			return (ENXIO);
485		g_topology_lock();
486		mtx_lock(&g_gate_list_mtx);
487		error = g_gate_destroy(sc, ggio->gctl_force);
488		if (error == 0)
489			g_gate_wither(sc);
490		g_topology_unlock();
491		g_gate_release(sc);
492		return (error);
493	    }
494	case G_GATE_CMD_CANCEL:
495	    {
496		struct g_gate_ctl_cancel *ggio = (void *)addr;
497		struct bio *tbp, *lbp;
498
499		G_GATE_CHECK_VERSION(ggio);
500		sc = g_gate_hold(ggio->gctl_unit);
501		if (sc == NULL)
502			return (ENXIO);
503		lbp = NULL;
504		mtx_lock(&sc->sc_queue_mtx);
505		TAILQ_FOREACH_SAFE(bp, &sc->sc_outqueue.queue, bio_queue, tbp) {
506			if (ggio->gctl_seq == 0 ||
507			    ggio->gctl_seq == (uintptr_t)bp->bio_driver1) {
508				G_GATE_LOGREQ(1, bp, "Request canceled.");
509				bioq_remove(&sc->sc_outqueue, bp);
510				/*
511				 * Be sure to put requests back onto incoming
512				 * queue in the proper order.
513				 */
514				if (lbp == NULL)
515					bioq_insert_head(&sc->sc_inqueue, bp);
516				else {
517					TAILQ_INSERT_AFTER(&sc->sc_inqueue.queue,
518					    lbp, bp, bio_queue);
519				}
520				lbp = bp;
521				/*
522				 * If only one request was canceled, leave now.
523				 */
524				if (ggio->gctl_seq != 0)
525					break;
526			}
527		}
528		mtx_unlock(&sc->sc_queue_mtx);
529		g_gate_release(sc);
530		return (error);
531	    }
532	case G_GATE_CMD_START:
533	    {
534		struct g_gate_ctl_io *ggio = (void *)addr;
535
536		G_GATE_CHECK_VERSION(ggio);
537		sc = g_gate_find(ggio->gctl_unit);
538		if (sc == NULL)
539			return (ENXIO);
540		for (;;) {
541			mtx_lock(&sc->sc_queue_mtx);
542			bp = bioq_first(&sc->sc_inqueue);
543			if (bp != NULL)
544				break;
545			if (msleep(sc, &sc->sc_queue_mtx,
546			    PPAUSE | PDROP | PCATCH, "ggwait", 0) != 0) {
547				ggio->gctl_error = ECANCELED;
548				return (0);
549			}
550			if ((sc->sc_flags & G_GATE_FLAG_DESTROY) != 0) {
551				ggio->gctl_error = ECANCELED;
552				return (0);
553			}
554		}
555		ggio->gctl_cmd = bp->bio_cmd;
556		if ((bp->bio_cmd == BIO_DELETE || bp->bio_cmd == BIO_WRITE) &&
557		    bp->bio_length > ggio->gctl_length) {
558			mtx_unlock(&sc->sc_queue_mtx);
559			ggio->gctl_length = bp->bio_length;
560			ggio->gctl_error = ENOMEM;
561			return (0);
562		}
563		bioq_remove(&sc->sc_inqueue, bp);
564		bioq_insert_tail(&sc->sc_outqueue, bp);
565		mtx_unlock(&sc->sc_queue_mtx);
566
567		ggio->gctl_seq = (uintptr_t)bp->bio_driver1;
568		ggio->gctl_offset = bp->bio_offset;
569		ggio->gctl_length = bp->bio_length;
570
571		switch (bp->bio_cmd) {
572		case BIO_READ:
573			break;
574		case BIO_DELETE:
575		case BIO_WRITE:
576			error = copyout(bp->bio_data, ggio->gctl_data,
577			    bp->bio_length);
578			if (error != 0) {
579				mtx_lock(&sc->sc_queue_mtx);
580				bioq_remove(&sc->sc_outqueue, bp);
581				bioq_insert_head(&sc->sc_inqueue, bp);
582				mtx_unlock(&sc->sc_queue_mtx);
583				return (error);
584			}
585			break;
586		}
587		return (0);
588	    }
589	case G_GATE_CMD_DONE:
590	    {
591		struct g_gate_ctl_io *ggio = (void *)addr;
592
593		G_GATE_CHECK_VERSION(ggio);
594		sc = g_gate_find(ggio->gctl_unit);
595		if (sc == NULL)
596			return (ENOENT);
597		mtx_lock(&sc->sc_queue_mtx);
598		TAILQ_FOREACH(bp, &sc->sc_outqueue.queue, bio_queue) {
599			if (ggio->gctl_seq == (uintptr_t)bp->bio_driver1)
600				break;
601		}
602		if (bp != NULL) {
603			bioq_remove(&sc->sc_outqueue, bp);
604			sc->sc_queue_count--;
605		}
606		mtx_unlock(&sc->sc_queue_mtx);
607		if (bp == NULL) {
608			/*
609			 * Request was probably canceled.
610			 */
611			return (0);
612		}
613		if (ggio->gctl_error == EAGAIN) {
614			bp->bio_error = 0;
615			G_GATE_LOGREQ(1, bp, "Request desisted.");
616			mtx_lock(&sc->sc_queue_mtx);
617			sc->sc_queue_count++;
618			bioq_insert_head(&sc->sc_inqueue, bp);
619			wakeup(sc);
620			mtx_unlock(&sc->sc_queue_mtx);
621		} else {
622			bp->bio_error = ggio->gctl_error;
623			if (bp->bio_error == 0) {
624				bp->bio_completed = bp->bio_length;
625				switch (bp->bio_cmd) {
626				case BIO_READ:
627					error = copyin(ggio->gctl_data,
628					    bp->bio_data, bp->bio_length);
629					if (error != 0)
630						bp->bio_error = error;
631					break;
632				case BIO_DELETE:
633				case BIO_WRITE:
634					break;
635				}
636			}
637			G_GATE_LOGREQ(2, bp, "Request done.");
638			g_io_deliver(bp, bp->bio_error);
639		}
640		return (error);
641	    }
642	}
643	return (ENOIOCTL);
644}
645
646static void
647g_gate_device(void)
648{
649
650	status_dev = make_dev(&g_gate_cdevsw, 0x0, UID_ROOT, GID_WHEEL, 0600,
651	    G_GATE_CTL_NAME);
652}
653
654static int
655g_gate_modevent(module_t mod, int type, void *data)
656{
657	int error = 0;
658
659	switch (type) {
660	case MOD_LOAD:
661		mtx_init(&g_gate_list_mtx, "gg_list_lock", NULL, MTX_DEF);
662		g_gate_device();
663		break;
664	case MOD_UNLOAD:
665		mtx_lock(&g_gate_list_mtx);
666		if (!LIST_EMPTY(&g_gate_list)) {
667			mtx_unlock(&g_gate_list_mtx);
668			error = EBUSY;
669			break;
670		}
671		mtx_unlock(&g_gate_list_mtx);
672		mtx_destroy(&g_gate_list_mtx);
673		if (status_dev != 0)
674			destroy_dev(status_dev);
675		break;
676	default:
677		return (EOPNOTSUPP);
678		break;
679	}
680
681	return (error);
682}
683static moduledata_t g_gate_module = {
684	G_GATE_MOD_NAME,
685	g_gate_modevent,
686	NULL
687};
688DECLARE_MODULE(geom_gate, g_gate_module, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
689DECLARE_GEOM_CLASS(g_gate_class, g_gate);
690