g_mirror.c revision 211455
1/*-
2 * Copyright (c) 2004-2006 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
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/geom/mirror/g_mirror.c 211455 2010-08-18 15:38:10Z mav $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/module.h>
34#include <sys/limits.h>
35#include <sys/lock.h>
36#include <sys/mutex.h>
37#include <sys/bio.h>
38#include <sys/sysctl.h>
39#include <sys/malloc.h>
40#include <sys/eventhandler.h>
41#include <vm/uma.h>
42#include <geom/geom.h>
43#include <sys/proc.h>
44#include <sys/kthread.h>
45#include <sys/sched.h>
46#include <geom/mirror/g_mirror.h>
47
48
49static MALLOC_DEFINE(M_MIRROR, "mirror_data", "GEOM_MIRROR Data");
50
51SYSCTL_DECL(_kern_geom);
52SYSCTL_NODE(_kern_geom, OID_AUTO, mirror, CTLFLAG_RW, 0, "GEOM_MIRROR stuff");
53u_int g_mirror_debug = 0;
54TUNABLE_INT("kern.geom.mirror.debug", &g_mirror_debug);
55SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, debug, CTLFLAG_RW, &g_mirror_debug, 0,
56    "Debug level");
57static u_int g_mirror_timeout = 4;
58TUNABLE_INT("kern.geom.mirror.timeout", &g_mirror_timeout);
59SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, timeout, CTLFLAG_RW, &g_mirror_timeout,
60    0, "Time to wait on all mirror components");
61static u_int g_mirror_idletime = 5;
62TUNABLE_INT("kern.geom.mirror.idletime", &g_mirror_idletime);
63SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, idletime, CTLFLAG_RW,
64    &g_mirror_idletime, 0, "Mark components as clean when idling");
65static u_int g_mirror_disconnect_on_failure = 1;
66TUNABLE_INT("kern.geom.mirror.disconnect_on_failure",
67    &g_mirror_disconnect_on_failure);
68SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, disconnect_on_failure, CTLFLAG_RW,
69    &g_mirror_disconnect_on_failure, 0, "Disconnect component on I/O failure.");
70static u_int g_mirror_syncreqs = 2;
71TUNABLE_INT("kern.geom.mirror.sync_requests", &g_mirror_syncreqs);
72SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, sync_requests, CTLFLAG_RDTUN,
73    &g_mirror_syncreqs, 0, "Parallel synchronization I/O requests.");
74
75#define	MSLEEP(ident, mtx, priority, wmesg, timeout)	do {		\
76	G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, (ident));	\
77	msleep((ident), (mtx), (priority), (wmesg), (timeout));		\
78	G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, (ident));	\
79} while (0)
80
81static eventhandler_tag g_mirror_pre_sync = NULL;
82
83static int g_mirror_destroy_geom(struct gctl_req *req, struct g_class *mp,
84    struct g_geom *gp);
85static g_taste_t g_mirror_taste;
86static void g_mirror_init(struct g_class *mp);
87static void g_mirror_fini(struct g_class *mp);
88
89struct g_class g_mirror_class = {
90	.name = G_MIRROR_CLASS_NAME,
91	.version = G_VERSION,
92	.ctlreq = g_mirror_config,
93	.taste = g_mirror_taste,
94	.destroy_geom = g_mirror_destroy_geom,
95	.init = g_mirror_init,
96	.fini = g_mirror_fini
97};
98
99
100static void g_mirror_destroy_provider(struct g_mirror_softc *sc);
101static int g_mirror_update_disk(struct g_mirror_disk *disk, u_int state);
102static void g_mirror_update_device(struct g_mirror_softc *sc, boolean_t force);
103static void g_mirror_dumpconf(struct sbuf *sb, const char *indent,
104    struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp);
105static void g_mirror_sync_stop(struct g_mirror_disk *disk, int type);
106static void g_mirror_register_request(struct bio *bp);
107static void g_mirror_sync_release(struct g_mirror_softc *sc);
108
109
110static const char *
111g_mirror_disk_state2str(int state)
112{
113
114	switch (state) {
115	case G_MIRROR_DISK_STATE_NONE:
116		return ("NONE");
117	case G_MIRROR_DISK_STATE_NEW:
118		return ("NEW");
119	case G_MIRROR_DISK_STATE_ACTIVE:
120		return ("ACTIVE");
121	case G_MIRROR_DISK_STATE_STALE:
122		return ("STALE");
123	case G_MIRROR_DISK_STATE_SYNCHRONIZING:
124		return ("SYNCHRONIZING");
125	case G_MIRROR_DISK_STATE_DISCONNECTED:
126		return ("DISCONNECTED");
127	case G_MIRROR_DISK_STATE_DESTROY:
128		return ("DESTROY");
129	default:
130		return ("INVALID");
131	}
132}
133
134static const char *
135g_mirror_device_state2str(int state)
136{
137
138	switch (state) {
139	case G_MIRROR_DEVICE_STATE_STARTING:
140		return ("STARTING");
141	case G_MIRROR_DEVICE_STATE_RUNNING:
142		return ("RUNNING");
143	default:
144		return ("INVALID");
145	}
146}
147
148static const char *
149g_mirror_get_diskname(struct g_mirror_disk *disk)
150{
151
152	if (disk->d_consumer == NULL || disk->d_consumer->provider == NULL)
153		return ("[unknown]");
154	return (disk->d_name);
155}
156
157/*
158 * --- Events handling functions ---
159 * Events in geom_mirror are used to maintain disks and device status
160 * from one thread to simplify locking.
161 */
162static void
163g_mirror_event_free(struct g_mirror_event *ep)
164{
165
166	free(ep, M_MIRROR);
167}
168
169int
170g_mirror_event_send(void *arg, int state, int flags)
171{
172	struct g_mirror_softc *sc;
173	struct g_mirror_disk *disk;
174	struct g_mirror_event *ep;
175	int error;
176
177	ep = malloc(sizeof(*ep), M_MIRROR, M_WAITOK);
178	G_MIRROR_DEBUG(4, "%s: Sending event %p.", __func__, ep);
179	if ((flags & G_MIRROR_EVENT_DEVICE) != 0) {
180		disk = NULL;
181		sc = arg;
182	} else {
183		disk = arg;
184		sc = disk->d_softc;
185	}
186	ep->e_disk = disk;
187	ep->e_state = state;
188	ep->e_flags = flags;
189	ep->e_error = 0;
190	mtx_lock(&sc->sc_events_mtx);
191	TAILQ_INSERT_TAIL(&sc->sc_events, ep, e_next);
192	mtx_unlock(&sc->sc_events_mtx);
193	G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
194	mtx_lock(&sc->sc_queue_mtx);
195	wakeup(sc);
196	mtx_unlock(&sc->sc_queue_mtx);
197	if ((flags & G_MIRROR_EVENT_DONTWAIT) != 0)
198		return (0);
199	sx_assert(&sc->sc_lock, SX_XLOCKED);
200	G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, ep);
201	sx_xunlock(&sc->sc_lock);
202	while ((ep->e_flags & G_MIRROR_EVENT_DONE) == 0) {
203		mtx_lock(&sc->sc_events_mtx);
204		MSLEEP(ep, &sc->sc_events_mtx, PRIBIO | PDROP, "m:event",
205		    hz * 5);
206	}
207	error = ep->e_error;
208	g_mirror_event_free(ep);
209	sx_xlock(&sc->sc_lock);
210	return (error);
211}
212
213static struct g_mirror_event *
214g_mirror_event_get(struct g_mirror_softc *sc)
215{
216	struct g_mirror_event *ep;
217
218	mtx_lock(&sc->sc_events_mtx);
219	ep = TAILQ_FIRST(&sc->sc_events);
220	mtx_unlock(&sc->sc_events_mtx);
221	return (ep);
222}
223
224static void
225g_mirror_event_remove(struct g_mirror_softc *sc, struct g_mirror_event *ep)
226{
227
228	mtx_lock(&sc->sc_events_mtx);
229	TAILQ_REMOVE(&sc->sc_events, ep, e_next);
230	mtx_unlock(&sc->sc_events_mtx);
231}
232
233static void
234g_mirror_event_cancel(struct g_mirror_disk *disk)
235{
236	struct g_mirror_softc *sc;
237	struct g_mirror_event *ep, *tmpep;
238
239	sc = disk->d_softc;
240	sx_assert(&sc->sc_lock, SX_XLOCKED);
241
242	mtx_lock(&sc->sc_events_mtx);
243	TAILQ_FOREACH_SAFE(ep, &sc->sc_events, e_next, tmpep) {
244		if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0)
245			continue;
246		if (ep->e_disk != disk)
247			continue;
248		TAILQ_REMOVE(&sc->sc_events, ep, e_next);
249		if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
250			g_mirror_event_free(ep);
251		else {
252			ep->e_error = ECANCELED;
253			wakeup(ep);
254		}
255	}
256	mtx_unlock(&sc->sc_events_mtx);
257}
258
259/*
260 * Return the number of disks in given state.
261 * If state is equal to -1, count all connected disks.
262 */
263u_int
264g_mirror_ndisks(struct g_mirror_softc *sc, int state)
265{
266	struct g_mirror_disk *disk;
267	u_int n = 0;
268
269	sx_assert(&sc->sc_lock, SX_LOCKED);
270
271	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
272		if (state == -1 || disk->d_state == state)
273			n++;
274	}
275	return (n);
276}
277
278/*
279 * Find a disk in mirror by its disk ID.
280 */
281static struct g_mirror_disk *
282g_mirror_id2disk(struct g_mirror_softc *sc, uint32_t id)
283{
284	struct g_mirror_disk *disk;
285
286	sx_assert(&sc->sc_lock, SX_XLOCKED);
287
288	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
289		if (disk->d_id == id)
290			return (disk);
291	}
292	return (NULL);
293}
294
295static u_int
296g_mirror_nrequests(struct g_mirror_softc *sc, struct g_consumer *cp)
297{
298	struct bio *bp;
299	u_int nreqs = 0;
300
301	mtx_lock(&sc->sc_queue_mtx);
302	TAILQ_FOREACH(bp, &sc->sc_queue.queue, bio_queue) {
303		if (bp->bio_from == cp)
304			nreqs++;
305	}
306	mtx_unlock(&sc->sc_queue_mtx);
307	return (nreqs);
308}
309
310static int
311g_mirror_is_busy(struct g_mirror_softc *sc, struct g_consumer *cp)
312{
313
314	if (cp->index > 0) {
315		G_MIRROR_DEBUG(2,
316		    "I/O requests for %s exist, can't destroy it now.",
317		    cp->provider->name);
318		return (1);
319	}
320	if (g_mirror_nrequests(sc, cp) > 0) {
321		G_MIRROR_DEBUG(2,
322		    "I/O requests for %s in queue, can't destroy it now.",
323		    cp->provider->name);
324		return (1);
325	}
326	return (0);
327}
328
329static void
330g_mirror_destroy_consumer(void *arg, int flags __unused)
331{
332	struct g_consumer *cp;
333
334	g_topology_assert();
335
336	cp = arg;
337	G_MIRROR_DEBUG(1, "Consumer %s destroyed.", cp->provider->name);
338	g_detach(cp);
339	g_destroy_consumer(cp);
340}
341
342static void
343g_mirror_kill_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
344{
345	struct g_provider *pp;
346	int retaste_wait;
347
348	g_topology_assert();
349
350	cp->private = NULL;
351	if (g_mirror_is_busy(sc, cp))
352		return;
353	pp = cp->provider;
354	retaste_wait = 0;
355	if (cp->acw == 1) {
356		if ((pp->geom->flags & G_GEOM_WITHER) == 0)
357			retaste_wait = 1;
358	}
359	G_MIRROR_DEBUG(2, "Access %s r%dw%de%d = %d", pp->name, -cp->acr,
360	    -cp->acw, -cp->ace, 0);
361	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
362		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
363	if (retaste_wait) {
364		/*
365		 * After retaste event was send (inside g_access()), we can send
366		 * event to detach and destroy consumer.
367		 * A class, which has consumer to the given provider connected
368		 * will not receive retaste event for the provider.
369		 * This is the way how I ignore retaste events when I close
370		 * consumers opened for write: I detach and destroy consumer
371		 * after retaste event is sent.
372		 */
373		g_post_event(g_mirror_destroy_consumer, cp, M_WAITOK, NULL);
374		return;
375	}
376	G_MIRROR_DEBUG(1, "Consumer %s destroyed.", pp->name);
377	g_detach(cp);
378	g_destroy_consumer(cp);
379}
380
381static int
382g_mirror_connect_disk(struct g_mirror_disk *disk, struct g_provider *pp)
383{
384	struct g_consumer *cp;
385	int error;
386
387	g_topology_assert_not();
388	KASSERT(disk->d_consumer == NULL,
389	    ("Disk already connected (device %s).", disk->d_softc->sc_name));
390
391	g_topology_lock();
392	cp = g_new_consumer(disk->d_softc->sc_geom);
393	error = g_attach(cp, pp);
394	if (error != 0) {
395		g_destroy_consumer(cp);
396		g_topology_unlock();
397		return (error);
398	}
399	error = g_access(cp, 1, 1, 1);
400	if (error != 0) {
401		g_detach(cp);
402		g_destroy_consumer(cp);
403		g_topology_unlock();
404		G_MIRROR_DEBUG(0, "Cannot open consumer %s (error=%d).",
405		    pp->name, error);
406		return (error);
407	}
408	g_topology_unlock();
409	disk->d_consumer = cp;
410	disk->d_consumer->private = disk;
411	disk->d_consumer->index = 0;
412
413	G_MIRROR_DEBUG(2, "Disk %s connected.", g_mirror_get_diskname(disk));
414	return (0);
415}
416
417static void
418g_mirror_disconnect_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
419{
420
421	g_topology_assert();
422
423	if (cp == NULL)
424		return;
425	if (cp->provider != NULL)
426		g_mirror_kill_consumer(sc, cp);
427	else
428		g_destroy_consumer(cp);
429}
430
431/*
432 * Initialize disk. This means allocate memory, create consumer, attach it
433 * to the provider and open access (r1w1e1) to it.
434 */
435static struct g_mirror_disk *
436g_mirror_init_disk(struct g_mirror_softc *sc, struct g_provider *pp,
437    struct g_mirror_metadata *md, int *errorp)
438{
439	struct g_mirror_disk *disk;
440	int error;
441
442	disk = malloc(sizeof(*disk), M_MIRROR, M_NOWAIT | M_ZERO);
443	if (disk == NULL) {
444		error = ENOMEM;
445		goto fail;
446	}
447	disk->d_softc = sc;
448	error = g_mirror_connect_disk(disk, pp);
449	if (error != 0)
450		goto fail;
451	disk->d_id = md->md_did;
452	disk->d_state = G_MIRROR_DISK_STATE_NONE;
453	disk->d_priority = md->md_priority;
454	disk->d_flags = md->md_dflags;
455	if (md->md_provider[0] != '\0')
456		disk->d_flags |= G_MIRROR_DISK_FLAG_HARDCODED;
457	disk->d_sync.ds_consumer = NULL;
458	disk->d_sync.ds_offset = md->md_sync_offset;
459	disk->d_sync.ds_offset_done = md->md_sync_offset;
460	disk->d_genid = md->md_genid;
461	disk->d_sync.ds_syncid = md->md_syncid;
462	if (errorp != NULL)
463		*errorp = 0;
464	return (disk);
465fail:
466	if (errorp != NULL)
467		*errorp = error;
468	if (disk != NULL)
469		free(disk, M_MIRROR);
470	return (NULL);
471}
472
473static void
474g_mirror_destroy_disk(struct g_mirror_disk *disk)
475{
476	struct g_mirror_softc *sc;
477
478	g_topology_assert_not();
479	sc = disk->d_softc;
480	sx_assert(&sc->sc_lock, SX_XLOCKED);
481
482	LIST_REMOVE(disk, d_next);
483	g_mirror_event_cancel(disk);
484	if (sc->sc_hint == disk)
485		sc->sc_hint = NULL;
486	switch (disk->d_state) {
487	case G_MIRROR_DISK_STATE_SYNCHRONIZING:
488		g_mirror_sync_stop(disk, 1);
489		/* FALLTHROUGH */
490	case G_MIRROR_DISK_STATE_NEW:
491	case G_MIRROR_DISK_STATE_STALE:
492	case G_MIRROR_DISK_STATE_ACTIVE:
493		g_topology_lock();
494		g_mirror_disconnect_consumer(sc, disk->d_consumer);
495		g_topology_unlock();
496		free(disk, M_MIRROR);
497		break;
498	default:
499		KASSERT(0 == 1, ("Wrong disk state (%s, %s).",
500		    g_mirror_get_diskname(disk),
501		    g_mirror_disk_state2str(disk->d_state)));
502	}
503}
504
505static void
506g_mirror_destroy_device(struct g_mirror_softc *sc)
507{
508	struct g_mirror_disk *disk;
509	struct g_mirror_event *ep;
510	struct g_geom *gp;
511	struct g_consumer *cp, *tmpcp;
512
513	g_topology_assert_not();
514	sx_assert(&sc->sc_lock, SX_XLOCKED);
515
516	gp = sc->sc_geom;
517	if (sc->sc_provider != NULL)
518		g_mirror_destroy_provider(sc);
519	for (disk = LIST_FIRST(&sc->sc_disks); disk != NULL;
520	    disk = LIST_FIRST(&sc->sc_disks)) {
521		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
522		g_mirror_update_metadata(disk);
523		g_mirror_destroy_disk(disk);
524	}
525	while ((ep = g_mirror_event_get(sc)) != NULL) {
526		g_mirror_event_remove(sc, ep);
527		if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
528			g_mirror_event_free(ep);
529		else {
530			ep->e_error = ECANCELED;
531			ep->e_flags |= G_MIRROR_EVENT_DONE;
532			G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, ep);
533			mtx_lock(&sc->sc_events_mtx);
534			wakeup(ep);
535			mtx_unlock(&sc->sc_events_mtx);
536		}
537	}
538	callout_drain(&sc->sc_callout);
539
540	g_topology_lock();
541	LIST_FOREACH_SAFE(cp, &sc->sc_sync.ds_geom->consumer, consumer, tmpcp) {
542		g_mirror_disconnect_consumer(sc, cp);
543	}
544	g_wither_geom(sc->sc_sync.ds_geom, ENXIO);
545	G_MIRROR_DEBUG(0, "Device %s destroyed.", gp->name);
546	g_wither_geom(gp, ENXIO);
547	g_topology_unlock();
548	mtx_destroy(&sc->sc_queue_mtx);
549	mtx_destroy(&sc->sc_events_mtx);
550	sx_xunlock(&sc->sc_lock);
551	sx_destroy(&sc->sc_lock);
552}
553
554static void
555g_mirror_orphan(struct g_consumer *cp)
556{
557	struct g_mirror_disk *disk;
558
559	g_topology_assert();
560
561	disk = cp->private;
562	if (disk == NULL)
563		return;
564	disk->d_softc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
565	g_mirror_event_send(disk, G_MIRROR_DISK_STATE_DISCONNECTED,
566	    G_MIRROR_EVENT_DONTWAIT);
567}
568
569/*
570 * Function should return the next active disk on the list.
571 * It is possible that it will be the same disk as given.
572 * If there are no active disks on list, NULL is returned.
573 */
574static __inline struct g_mirror_disk *
575g_mirror_find_next(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
576{
577	struct g_mirror_disk *dp;
578
579	for (dp = LIST_NEXT(disk, d_next); dp != disk;
580	    dp = LIST_NEXT(dp, d_next)) {
581		if (dp == NULL)
582			dp = LIST_FIRST(&sc->sc_disks);
583		if (dp->d_state == G_MIRROR_DISK_STATE_ACTIVE)
584			break;
585	}
586	if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
587		return (NULL);
588	return (dp);
589}
590
591static struct g_mirror_disk *
592g_mirror_get_disk(struct g_mirror_softc *sc)
593{
594	struct g_mirror_disk *disk;
595
596	if (sc->sc_hint == NULL) {
597		sc->sc_hint = LIST_FIRST(&sc->sc_disks);
598		if (sc->sc_hint == NULL)
599			return (NULL);
600	}
601	disk = sc->sc_hint;
602	if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE) {
603		disk = g_mirror_find_next(sc, disk);
604		if (disk == NULL)
605			return (NULL);
606	}
607	sc->sc_hint = g_mirror_find_next(sc, disk);
608	return (disk);
609}
610
611static int
612g_mirror_write_metadata(struct g_mirror_disk *disk,
613    struct g_mirror_metadata *md)
614{
615	struct g_mirror_softc *sc;
616	struct g_consumer *cp;
617	off_t offset, length;
618	u_char *sector;
619	int error = 0;
620
621	g_topology_assert_not();
622	sc = disk->d_softc;
623	sx_assert(&sc->sc_lock, SX_LOCKED);
624
625	cp = disk->d_consumer;
626	KASSERT(cp != NULL, ("NULL consumer (%s).", sc->sc_name));
627	KASSERT(cp->provider != NULL, ("NULL provider (%s).", sc->sc_name));
628	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
629	    ("Consumer %s closed? (r%dw%de%d).", cp->provider->name, cp->acr,
630	    cp->acw, cp->ace));
631	length = cp->provider->sectorsize;
632	offset = cp->provider->mediasize - length;
633	sector = malloc((size_t)length, M_MIRROR, M_WAITOK | M_ZERO);
634	if (md != NULL)
635		mirror_metadata_encode(md, sector);
636	error = g_write_data(cp, offset, sector, length);
637	free(sector, M_MIRROR);
638	if (error != 0) {
639		if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
640			disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
641			G_MIRROR_DEBUG(0, "Cannot write metadata on %s "
642			    "(device=%s, error=%d).",
643			    g_mirror_get_diskname(disk), sc->sc_name, error);
644		} else {
645			G_MIRROR_DEBUG(1, "Cannot write metadata on %s "
646			    "(device=%s, error=%d).",
647			    g_mirror_get_diskname(disk), sc->sc_name, error);
648		}
649		if (g_mirror_disconnect_on_failure &&
650		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1) {
651			sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
652			g_mirror_event_send(disk,
653			    G_MIRROR_DISK_STATE_DISCONNECTED,
654			    G_MIRROR_EVENT_DONTWAIT);
655		}
656	}
657	return (error);
658}
659
660static int
661g_mirror_clear_metadata(struct g_mirror_disk *disk)
662{
663	int error;
664
665	g_topology_assert_not();
666	sx_assert(&disk->d_softc->sc_lock, SX_LOCKED);
667
668	error = g_mirror_write_metadata(disk, NULL);
669	if (error == 0) {
670		G_MIRROR_DEBUG(2, "Metadata on %s cleared.",
671		    g_mirror_get_diskname(disk));
672	} else {
673		G_MIRROR_DEBUG(0,
674		    "Cannot clear metadata on disk %s (error=%d).",
675		    g_mirror_get_diskname(disk), error);
676	}
677	return (error);
678}
679
680void
681g_mirror_fill_metadata(struct g_mirror_softc *sc, struct g_mirror_disk *disk,
682    struct g_mirror_metadata *md)
683{
684
685	strlcpy(md->md_magic, G_MIRROR_MAGIC, sizeof(md->md_magic));
686	md->md_version = G_MIRROR_VERSION;
687	strlcpy(md->md_name, sc->sc_name, sizeof(md->md_name));
688	md->md_mid = sc->sc_id;
689	md->md_all = sc->sc_ndisks;
690	md->md_slice = sc->sc_slice;
691	md->md_balance = sc->sc_balance;
692	md->md_genid = sc->sc_genid;
693	md->md_mediasize = sc->sc_mediasize;
694	md->md_sectorsize = sc->sc_sectorsize;
695	md->md_mflags = (sc->sc_flags & G_MIRROR_DEVICE_FLAG_MASK);
696	bzero(md->md_provider, sizeof(md->md_provider));
697	if (disk == NULL) {
698		md->md_did = arc4random();
699		md->md_priority = 0;
700		md->md_syncid = 0;
701		md->md_dflags = 0;
702		md->md_sync_offset = 0;
703		md->md_provsize = 0;
704	} else {
705		md->md_did = disk->d_id;
706		md->md_priority = disk->d_priority;
707		md->md_syncid = disk->d_sync.ds_syncid;
708		md->md_dflags = (disk->d_flags & G_MIRROR_DISK_FLAG_MASK);
709		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
710			md->md_sync_offset = disk->d_sync.ds_offset_done;
711		else
712			md->md_sync_offset = 0;
713		if ((disk->d_flags & G_MIRROR_DISK_FLAG_HARDCODED) != 0) {
714			strlcpy(md->md_provider,
715			    disk->d_consumer->provider->name,
716			    sizeof(md->md_provider));
717		}
718		md->md_provsize = disk->d_consumer->provider->mediasize;
719	}
720}
721
722void
723g_mirror_update_metadata(struct g_mirror_disk *disk)
724{
725	struct g_mirror_softc *sc;
726	struct g_mirror_metadata md;
727	int error;
728
729	g_topology_assert_not();
730	sc = disk->d_softc;
731	sx_assert(&sc->sc_lock, SX_LOCKED);
732
733	g_mirror_fill_metadata(sc, disk, &md);
734	error = g_mirror_write_metadata(disk, &md);
735	if (error == 0) {
736		G_MIRROR_DEBUG(2, "Metadata on %s updated.",
737		    g_mirror_get_diskname(disk));
738	} else {
739		G_MIRROR_DEBUG(0,
740		    "Cannot update metadata on disk %s (error=%d).",
741		    g_mirror_get_diskname(disk), error);
742	}
743}
744
745static void
746g_mirror_bump_syncid(struct g_mirror_softc *sc)
747{
748	struct g_mirror_disk *disk;
749
750	g_topology_assert_not();
751	sx_assert(&sc->sc_lock, SX_XLOCKED);
752	KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
753	    ("%s called with no active disks (device=%s).", __func__,
754	    sc->sc_name));
755
756	sc->sc_syncid++;
757	G_MIRROR_DEBUG(1, "Device %s: syncid bumped to %u.", sc->sc_name,
758	    sc->sc_syncid);
759	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
760		if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
761		    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
762			disk->d_sync.ds_syncid = sc->sc_syncid;
763			g_mirror_update_metadata(disk);
764		}
765	}
766}
767
768static void
769g_mirror_bump_genid(struct g_mirror_softc *sc)
770{
771	struct g_mirror_disk *disk;
772
773	g_topology_assert_not();
774	sx_assert(&sc->sc_lock, SX_XLOCKED);
775	KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
776	    ("%s called with no active disks (device=%s).", __func__,
777	    sc->sc_name));
778
779	sc->sc_genid++;
780	G_MIRROR_DEBUG(1, "Device %s: genid bumped to %u.", sc->sc_name,
781	    sc->sc_genid);
782	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
783		if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
784		    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
785			disk->d_genid = sc->sc_genid;
786			g_mirror_update_metadata(disk);
787		}
788	}
789}
790
791static int
792g_mirror_idle(struct g_mirror_softc *sc, int acw)
793{
794	struct g_mirror_disk *disk;
795	int timeout;
796
797	g_topology_assert_not();
798	sx_assert(&sc->sc_lock, SX_XLOCKED);
799
800	if (sc->sc_provider == NULL)
801		return (0);
802	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
803		return (0);
804	if (sc->sc_idle)
805		return (0);
806	if (sc->sc_writes > 0)
807		return (0);
808	if (acw > 0 || (acw == -1 && sc->sc_provider->acw > 0)) {
809		timeout = g_mirror_idletime - (time_uptime - sc->sc_last_write);
810		if (timeout > 0)
811			return (timeout);
812	}
813	sc->sc_idle = 1;
814	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
815		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
816			continue;
817		G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as clean.",
818		    g_mirror_get_diskname(disk), sc->sc_name);
819		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
820		g_mirror_update_metadata(disk);
821	}
822	return (0);
823}
824
825static void
826g_mirror_unidle(struct g_mirror_softc *sc)
827{
828	struct g_mirror_disk *disk;
829
830	g_topology_assert_not();
831	sx_assert(&sc->sc_lock, SX_XLOCKED);
832
833	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
834		return;
835	sc->sc_idle = 0;
836	sc->sc_last_write = time_uptime;
837	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
838		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
839			continue;
840		G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as dirty.",
841		    g_mirror_get_diskname(disk), sc->sc_name);
842		disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
843		g_mirror_update_metadata(disk);
844	}
845}
846
847static void
848g_mirror_done(struct bio *bp)
849{
850	struct g_mirror_softc *sc;
851
852	sc = bp->bio_from->geom->softc;
853	bp->bio_cflags = G_MIRROR_BIO_FLAG_REGULAR;
854	mtx_lock(&sc->sc_queue_mtx);
855	bioq_disksort(&sc->sc_queue, bp);
856	mtx_unlock(&sc->sc_queue_mtx);
857	wakeup(sc);
858}
859
860static void
861g_mirror_regular_request(struct bio *bp)
862{
863	struct g_mirror_softc *sc;
864	struct g_mirror_disk *disk;
865	struct bio *pbp;
866
867	g_topology_assert_not();
868
869	pbp = bp->bio_parent;
870	sc = pbp->bio_to->geom->softc;
871	bp->bio_from->index--;
872	if (bp->bio_cmd == BIO_WRITE)
873		sc->sc_writes--;
874	disk = bp->bio_from->private;
875	if (disk == NULL) {
876		g_topology_lock();
877		g_mirror_kill_consumer(sc, bp->bio_from);
878		g_topology_unlock();
879	}
880
881	pbp->bio_inbed++;
882	KASSERT(pbp->bio_inbed <= pbp->bio_children,
883	    ("bio_inbed (%u) is bigger than bio_children (%u).", pbp->bio_inbed,
884	    pbp->bio_children));
885	if (bp->bio_error == 0 && pbp->bio_error == 0) {
886		G_MIRROR_LOGREQ(3, bp, "Request delivered.");
887		g_destroy_bio(bp);
888		if (pbp->bio_children == pbp->bio_inbed) {
889			G_MIRROR_LOGREQ(3, pbp, "Request delivered.");
890			pbp->bio_completed = pbp->bio_length;
891			if (pbp->bio_cmd == BIO_WRITE) {
892				bioq_remove(&sc->sc_inflight, pbp);
893				/* Release delayed sync requests if possible. */
894				g_mirror_sync_release(sc);
895			}
896			g_io_deliver(pbp, pbp->bio_error);
897		}
898		return;
899	} else if (bp->bio_error != 0) {
900		if (pbp->bio_error == 0)
901			pbp->bio_error = bp->bio_error;
902		if (disk != NULL) {
903			if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
904				disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
905				G_MIRROR_LOGREQ(0, bp,
906				    "Request failed (error=%d).",
907				    bp->bio_error);
908			} else {
909				G_MIRROR_LOGREQ(1, bp,
910				    "Request failed (error=%d).",
911				    bp->bio_error);
912			}
913			if (g_mirror_disconnect_on_failure &&
914			    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1)
915			{
916				sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
917				g_mirror_event_send(disk,
918				    G_MIRROR_DISK_STATE_DISCONNECTED,
919				    G_MIRROR_EVENT_DONTWAIT);
920			}
921		}
922		switch (pbp->bio_cmd) {
923		case BIO_DELETE:
924		case BIO_WRITE:
925			pbp->bio_inbed--;
926			pbp->bio_children--;
927			break;
928		}
929	}
930	g_destroy_bio(bp);
931
932	switch (pbp->bio_cmd) {
933	case BIO_READ:
934		if (pbp->bio_inbed < pbp->bio_children)
935			break;
936		if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 1)
937			g_io_deliver(pbp, pbp->bio_error);
938		else {
939			pbp->bio_error = 0;
940			mtx_lock(&sc->sc_queue_mtx);
941			bioq_disksort(&sc->sc_queue, pbp);
942			mtx_unlock(&sc->sc_queue_mtx);
943			G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
944			wakeup(sc);
945		}
946		break;
947	case BIO_DELETE:
948	case BIO_WRITE:
949		if (pbp->bio_children == 0) {
950			/*
951			 * All requests failed.
952			 */
953		} else if (pbp->bio_inbed < pbp->bio_children) {
954			/* Do nothing. */
955			break;
956		} else if (pbp->bio_children == pbp->bio_inbed) {
957			/* Some requests succeeded. */
958			pbp->bio_error = 0;
959			pbp->bio_completed = pbp->bio_length;
960		}
961		bioq_remove(&sc->sc_inflight, pbp);
962		/* Release delayed sync requests if possible. */
963		g_mirror_sync_release(sc);
964		g_io_deliver(pbp, pbp->bio_error);
965		break;
966	default:
967		KASSERT(1 == 0, ("Invalid request: %u.", pbp->bio_cmd));
968		break;
969	}
970}
971
972static void
973g_mirror_sync_done(struct bio *bp)
974{
975	struct g_mirror_softc *sc;
976
977	G_MIRROR_LOGREQ(3, bp, "Synchronization request delivered.");
978	sc = bp->bio_from->geom->softc;
979	bp->bio_cflags = G_MIRROR_BIO_FLAG_SYNC;
980	mtx_lock(&sc->sc_queue_mtx);
981	bioq_disksort(&sc->sc_queue, bp);
982	mtx_unlock(&sc->sc_queue_mtx);
983	wakeup(sc);
984}
985
986static void
987g_mirror_kernel_dump(struct bio *bp)
988{
989	struct g_mirror_softc *sc;
990	struct g_mirror_disk *disk;
991	struct bio *cbp;
992	struct g_kerneldump *gkd;
993
994	/*
995	 * We configure dumping to the first component, because this component
996	 * will be used for reading with 'prefer' balance algorithm.
997	 * If the component with the higest priority is currently disconnected
998	 * we will not be able to read the dump after the reboot if it will be
999	 * connected and synchronized later. Can we do something better?
1000	 */
1001	sc = bp->bio_to->geom->softc;
1002	disk = LIST_FIRST(&sc->sc_disks);
1003
1004	gkd = (struct g_kerneldump *)bp->bio_data;
1005	if (gkd->length > bp->bio_to->mediasize)
1006		gkd->length = bp->bio_to->mediasize;
1007	cbp = g_clone_bio(bp);
1008	if (cbp == NULL) {
1009		g_io_deliver(bp, ENOMEM);
1010		return;
1011	}
1012	cbp->bio_done = g_std_done;
1013	g_io_request(cbp, disk->d_consumer);
1014	G_MIRROR_DEBUG(1, "Kernel dump will go to %s.",
1015	    g_mirror_get_diskname(disk));
1016}
1017
1018static void
1019g_mirror_flush(struct g_mirror_softc *sc, struct bio *bp)
1020{
1021	struct bio_queue_head queue;
1022	struct g_mirror_disk *disk;
1023	struct g_consumer *cp;
1024	struct bio *cbp;
1025
1026	bioq_init(&queue);
1027	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1028		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1029			continue;
1030		cbp = g_clone_bio(bp);
1031		if (cbp == NULL) {
1032			for (cbp = bioq_first(&queue); cbp != NULL;
1033			    cbp = bioq_first(&queue)) {
1034				bioq_remove(&queue, cbp);
1035				g_destroy_bio(cbp);
1036			}
1037			if (bp->bio_error == 0)
1038				bp->bio_error = ENOMEM;
1039			g_io_deliver(bp, bp->bio_error);
1040			return;
1041		}
1042		bioq_insert_tail(&queue, cbp);
1043		cbp->bio_done = g_std_done;
1044		cbp->bio_caller1 = disk;
1045		cbp->bio_to = disk->d_consumer->provider;
1046	}
1047	for (cbp = bioq_first(&queue); cbp != NULL; cbp = bioq_first(&queue)) {
1048		bioq_remove(&queue, cbp);
1049		G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1050		disk = cbp->bio_caller1;
1051		cbp->bio_caller1 = NULL;
1052		cp = disk->d_consumer;
1053		KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1054		    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1055		    cp->acr, cp->acw, cp->ace));
1056		g_io_request(cbp, disk->d_consumer);
1057	}
1058}
1059
1060static void
1061g_mirror_start(struct bio *bp)
1062{
1063	struct g_mirror_softc *sc;
1064
1065	sc = bp->bio_to->geom->softc;
1066	/*
1067	 * If sc == NULL or there are no valid disks, provider's error
1068	 * should be set and g_mirror_start() should not be called at all.
1069	 */
1070	KASSERT(sc != NULL && sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
1071	    ("Provider's error should be set (error=%d)(mirror=%s).",
1072	    bp->bio_to->error, bp->bio_to->name));
1073	G_MIRROR_LOGREQ(3, bp, "Request received.");
1074
1075	switch (bp->bio_cmd) {
1076	case BIO_READ:
1077	case BIO_WRITE:
1078	case BIO_DELETE:
1079		break;
1080	case BIO_FLUSH:
1081		g_mirror_flush(sc, bp);
1082		return;
1083	case BIO_GETATTR:
1084		if (strcmp("GEOM::kerneldump", bp->bio_attribute) == 0) {
1085			g_mirror_kernel_dump(bp);
1086			return;
1087		}
1088		/* FALLTHROUGH */
1089	default:
1090		g_io_deliver(bp, EOPNOTSUPP);
1091		return;
1092	}
1093	mtx_lock(&sc->sc_queue_mtx);
1094	bioq_disksort(&sc->sc_queue, bp);
1095	mtx_unlock(&sc->sc_queue_mtx);
1096	G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
1097	wakeup(sc);
1098}
1099
1100/*
1101 * Return TRUE if the given request is colliding with a in-progress
1102 * synchronization request.
1103 */
1104static int
1105g_mirror_sync_collision(struct g_mirror_softc *sc, struct bio *bp)
1106{
1107	struct g_mirror_disk *disk;
1108	struct bio *sbp;
1109	off_t rstart, rend, sstart, send;
1110	int i;
1111
1112	if (sc->sc_sync.ds_ndisks == 0)
1113		return (0);
1114	rstart = bp->bio_offset;
1115	rend = bp->bio_offset + bp->bio_length;
1116	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1117		if (disk->d_state != G_MIRROR_DISK_STATE_SYNCHRONIZING)
1118			continue;
1119		for (i = 0; i < g_mirror_syncreqs; i++) {
1120			sbp = disk->d_sync.ds_bios[i];
1121			if (sbp == NULL)
1122				continue;
1123			sstart = sbp->bio_offset;
1124			send = sbp->bio_offset + sbp->bio_length;
1125			if (rend > sstart && rstart < send)
1126				return (1);
1127		}
1128	}
1129	return (0);
1130}
1131
1132/*
1133 * Return TRUE if the given sync request is colliding with a in-progress regular
1134 * request.
1135 */
1136static int
1137g_mirror_regular_collision(struct g_mirror_softc *sc, struct bio *sbp)
1138{
1139	off_t rstart, rend, sstart, send;
1140	struct bio *bp;
1141
1142	if (sc->sc_sync.ds_ndisks == 0)
1143		return (0);
1144	sstart = sbp->bio_offset;
1145	send = sbp->bio_offset + sbp->bio_length;
1146	TAILQ_FOREACH(bp, &sc->sc_inflight.queue, bio_queue) {
1147		rstart = bp->bio_offset;
1148		rend = bp->bio_offset + bp->bio_length;
1149		if (rend > sstart && rstart < send)
1150			return (1);
1151	}
1152	return (0);
1153}
1154
1155/*
1156 * Puts request onto delayed queue.
1157 */
1158static void
1159g_mirror_regular_delay(struct g_mirror_softc *sc, struct bio *bp)
1160{
1161
1162	G_MIRROR_LOGREQ(2, bp, "Delaying request.");
1163	bioq_insert_head(&sc->sc_regular_delayed, bp);
1164}
1165
1166/*
1167 * Puts synchronization request onto delayed queue.
1168 */
1169static void
1170g_mirror_sync_delay(struct g_mirror_softc *sc, struct bio *bp)
1171{
1172
1173	G_MIRROR_LOGREQ(2, bp, "Delaying synchronization request.");
1174	bioq_insert_tail(&sc->sc_sync_delayed, bp);
1175}
1176
1177/*
1178 * Releases delayed regular requests which don't collide anymore with sync
1179 * requests.
1180 */
1181static void
1182g_mirror_regular_release(struct g_mirror_softc *sc)
1183{
1184	struct bio *bp, *bp2;
1185
1186	TAILQ_FOREACH_SAFE(bp, &sc->sc_regular_delayed.queue, bio_queue, bp2) {
1187		if (g_mirror_sync_collision(sc, bp))
1188			continue;
1189		bioq_remove(&sc->sc_regular_delayed, bp);
1190		G_MIRROR_LOGREQ(2, bp, "Releasing delayed request (%p).", bp);
1191		mtx_lock(&sc->sc_queue_mtx);
1192		bioq_insert_head(&sc->sc_queue, bp);
1193#if 0
1194		/*
1195		 * wakeup() is not needed, because this function is called from
1196		 * the worker thread.
1197		 */
1198		wakeup(&sc->sc_queue);
1199#endif
1200		mtx_unlock(&sc->sc_queue_mtx);
1201	}
1202}
1203
1204/*
1205 * Releases delayed sync requests which don't collide anymore with regular
1206 * requests.
1207 */
1208static void
1209g_mirror_sync_release(struct g_mirror_softc *sc)
1210{
1211	struct bio *bp, *bp2;
1212
1213	TAILQ_FOREACH_SAFE(bp, &sc->sc_sync_delayed.queue, bio_queue, bp2) {
1214		if (g_mirror_regular_collision(sc, bp))
1215			continue;
1216		bioq_remove(&sc->sc_sync_delayed, bp);
1217		G_MIRROR_LOGREQ(2, bp,
1218		    "Releasing delayed synchronization request.");
1219		g_io_request(bp, bp->bio_from);
1220	}
1221}
1222
1223/*
1224 * Handle synchronization requests.
1225 * Every synchronization request is two-steps process: first, READ request is
1226 * send to active provider and then WRITE request (with read data) to the provider
1227 * beeing synchronized. When WRITE is finished, new synchronization request is
1228 * send.
1229 */
1230static void
1231g_mirror_sync_request(struct bio *bp)
1232{
1233	struct g_mirror_softc *sc;
1234	struct g_mirror_disk *disk;
1235
1236	bp->bio_from->index--;
1237	sc = bp->bio_from->geom->softc;
1238	disk = bp->bio_from->private;
1239	if (disk == NULL) {
1240		sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
1241		g_topology_lock();
1242		g_mirror_kill_consumer(sc, bp->bio_from);
1243		g_topology_unlock();
1244		free(bp->bio_data, M_MIRROR);
1245		g_destroy_bio(bp);
1246		sx_xlock(&sc->sc_lock);
1247		return;
1248	}
1249
1250	/*
1251	 * Synchronization request.
1252	 */
1253	switch (bp->bio_cmd) {
1254	case BIO_READ:
1255	    {
1256		struct g_consumer *cp;
1257
1258		if (bp->bio_error != 0) {
1259			G_MIRROR_LOGREQ(0, bp,
1260			    "Synchronization request failed (error=%d).",
1261			    bp->bio_error);
1262			g_destroy_bio(bp);
1263			return;
1264		}
1265		G_MIRROR_LOGREQ(3, bp,
1266		    "Synchronization request half-finished.");
1267		bp->bio_cmd = BIO_WRITE;
1268		bp->bio_cflags = 0;
1269		cp = disk->d_consumer;
1270		KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1271		    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1272		    cp->acr, cp->acw, cp->ace));
1273		cp->index++;
1274		g_io_request(bp, cp);
1275		return;
1276	    }
1277	case BIO_WRITE:
1278	    {
1279		struct g_mirror_disk_sync *sync;
1280		off_t offset;
1281		void *data;
1282		int i;
1283
1284		if (bp->bio_error != 0) {
1285			G_MIRROR_LOGREQ(0, bp,
1286			    "Synchronization request failed (error=%d).",
1287			    bp->bio_error);
1288			g_destroy_bio(bp);
1289			sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
1290			g_mirror_event_send(disk,
1291			    G_MIRROR_DISK_STATE_DISCONNECTED,
1292			    G_MIRROR_EVENT_DONTWAIT);
1293			return;
1294		}
1295		G_MIRROR_LOGREQ(3, bp, "Synchronization request finished.");
1296		sync = &disk->d_sync;
1297		if (sync->ds_offset == sc->sc_mediasize ||
1298		    sync->ds_consumer == NULL ||
1299		    (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1300			/* Don't send more synchronization requests. */
1301			sync->ds_inflight--;
1302			if (sync->ds_bios != NULL) {
1303				i = (int)(uintptr_t)bp->bio_caller1;
1304				sync->ds_bios[i] = NULL;
1305			}
1306			free(bp->bio_data, M_MIRROR);
1307			g_destroy_bio(bp);
1308			if (sync->ds_inflight > 0)
1309				return;
1310			if (sync->ds_consumer == NULL ||
1311			    (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1312				return;
1313			}
1314			/* Disk up-to-date, activate it. */
1315			g_mirror_event_send(disk, G_MIRROR_DISK_STATE_ACTIVE,
1316			    G_MIRROR_EVENT_DONTWAIT);
1317			return;
1318		}
1319
1320		/* Send next synchronization request. */
1321		data = bp->bio_data;
1322		bzero(bp, sizeof(*bp));
1323		bp->bio_cmd = BIO_READ;
1324		bp->bio_offset = sync->ds_offset;
1325		bp->bio_length = MIN(MAXPHYS, sc->sc_mediasize - bp->bio_offset);
1326		sync->ds_offset += bp->bio_length;
1327		bp->bio_done = g_mirror_sync_done;
1328		bp->bio_data = data;
1329		bp->bio_from = sync->ds_consumer;
1330		bp->bio_to = sc->sc_provider;
1331		G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
1332		sync->ds_consumer->index++;
1333		/*
1334		 * Delay the request if it is colliding with a regular request.
1335		 */
1336		if (g_mirror_regular_collision(sc, bp))
1337			g_mirror_sync_delay(sc, bp);
1338		else
1339			g_io_request(bp, sync->ds_consumer);
1340
1341		/* Release delayed requests if possible. */
1342		g_mirror_regular_release(sc);
1343
1344		/* Find the smallest offset */
1345		offset = sc->sc_mediasize;
1346		for (i = 0; i < g_mirror_syncreqs; i++) {
1347			bp = sync->ds_bios[i];
1348			if (bp->bio_offset < offset)
1349				offset = bp->bio_offset;
1350		}
1351		if (sync->ds_offset_done + (MAXPHYS * 100) < offset) {
1352			/* Update offset_done on every 100 blocks. */
1353			sync->ds_offset_done = offset;
1354			g_mirror_update_metadata(disk);
1355		}
1356		return;
1357	    }
1358	default:
1359		KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
1360		    bp->bio_cmd, sc->sc_name));
1361		break;
1362	}
1363}
1364
1365static void
1366g_mirror_request_prefer(struct g_mirror_softc *sc, struct bio *bp)
1367{
1368	struct g_mirror_disk *disk;
1369	struct g_consumer *cp;
1370	struct bio *cbp;
1371
1372	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1373		if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE)
1374			break;
1375	}
1376	if (disk == NULL) {
1377		if (bp->bio_error == 0)
1378			bp->bio_error = ENXIO;
1379		g_io_deliver(bp, bp->bio_error);
1380		return;
1381	}
1382	cbp = g_clone_bio(bp);
1383	if (cbp == NULL) {
1384		if (bp->bio_error == 0)
1385			bp->bio_error = ENOMEM;
1386		g_io_deliver(bp, bp->bio_error);
1387		return;
1388	}
1389	/*
1390	 * Fill in the component buf structure.
1391	 */
1392	cp = disk->d_consumer;
1393	cbp->bio_done = g_mirror_done;
1394	cbp->bio_to = cp->provider;
1395	G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1396	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1397	    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1398	    cp->acw, cp->ace));
1399	cp->index++;
1400	g_io_request(cbp, cp);
1401}
1402
1403static void
1404g_mirror_request_round_robin(struct g_mirror_softc *sc, struct bio *bp)
1405{
1406	struct g_mirror_disk *disk;
1407	struct g_consumer *cp;
1408	struct bio *cbp;
1409
1410	disk = g_mirror_get_disk(sc);
1411	if (disk == NULL) {
1412		if (bp->bio_error == 0)
1413			bp->bio_error = ENXIO;
1414		g_io_deliver(bp, bp->bio_error);
1415		return;
1416	}
1417	cbp = g_clone_bio(bp);
1418	if (cbp == NULL) {
1419		if (bp->bio_error == 0)
1420			bp->bio_error = ENOMEM;
1421		g_io_deliver(bp, bp->bio_error);
1422		return;
1423	}
1424	/*
1425	 * Fill in the component buf structure.
1426	 */
1427	cp = disk->d_consumer;
1428	cbp->bio_done = g_mirror_done;
1429	cbp->bio_to = cp->provider;
1430	G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1431	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1432	    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1433	    cp->acw, cp->ace));
1434	cp->index++;
1435	g_io_request(cbp, cp);
1436}
1437
1438#define TRACK_SIZE  (1 * 1024 * 1024)
1439#define LOAD_SCALE	256
1440#define ABS(x)		(((x) >= 0) ? (x) : (-(x)))
1441
1442static void
1443g_mirror_request_load(struct g_mirror_softc *sc, struct bio *bp)
1444{
1445	struct g_mirror_disk *disk, *dp;
1446	struct g_consumer *cp;
1447	struct bio *cbp;
1448	int prio, best;
1449
1450	/* Find a disk with the smallest load. */
1451	disk = NULL;
1452	best = INT_MAX;
1453	LIST_FOREACH(dp, &sc->sc_disks, d_next) {
1454		if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1455			continue;
1456		prio = dp->load;
1457		/* If disk head is precisely in position - highly prefer it. */
1458		if (dp->d_last_offset == bp->bio_offset)
1459			prio -= 2 * LOAD_SCALE;
1460		else
1461		/* If disk head is close to position - prefer it. */
1462		if (ABS(dp->d_last_offset - bp->bio_offset) < TRACK_SIZE)
1463			prio -= 1 * LOAD_SCALE;
1464		if (prio <= best) {
1465			disk = dp;
1466			best = prio;
1467		}
1468	}
1469	KASSERT(disk != NULL, ("NULL disk for %s.", sc->sc_name));
1470	cbp = g_clone_bio(bp);
1471	if (cbp == NULL) {
1472		if (bp->bio_error == 0)
1473			bp->bio_error = ENOMEM;
1474		g_io_deliver(bp, bp->bio_error);
1475		return;
1476	}
1477	/*
1478	 * Fill in the component buf structure.
1479	 */
1480	cp = disk->d_consumer;
1481	cbp->bio_done = g_mirror_done;
1482	cbp->bio_to = cp->provider;
1483	G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1484	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1485	    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1486	    cp->acw, cp->ace));
1487	cp->index++;
1488	/* Remember last head position */
1489	disk->d_last_offset = bp->bio_offset + bp->bio_length;
1490	/* Update loads. */
1491	LIST_FOREACH(dp, &sc->sc_disks, d_next) {
1492		dp->load = (dp->d_consumer->index * LOAD_SCALE +
1493		    dp->load * 7) / 8;
1494	}
1495	g_io_request(cbp, cp);
1496}
1497
1498static void
1499g_mirror_request_split(struct g_mirror_softc *sc, struct bio *bp)
1500{
1501	struct bio_queue_head queue;
1502	struct g_mirror_disk *disk;
1503	struct g_consumer *cp;
1504	struct bio *cbp;
1505	off_t left, mod, offset, slice;
1506	u_char *data;
1507	u_int ndisks;
1508
1509	if (bp->bio_length <= sc->sc_slice) {
1510		g_mirror_request_round_robin(sc, bp);
1511		return;
1512	}
1513	ndisks = g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE);
1514	slice = bp->bio_length / ndisks;
1515	mod = slice % sc->sc_provider->sectorsize;
1516	if (mod != 0)
1517		slice += sc->sc_provider->sectorsize - mod;
1518	/*
1519	 * Allocate all bios before sending any request, so we can
1520	 * return ENOMEM in nice and clean way.
1521	 */
1522	left = bp->bio_length;
1523	offset = bp->bio_offset;
1524	data = bp->bio_data;
1525	bioq_init(&queue);
1526	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1527		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1528			continue;
1529		cbp = g_clone_bio(bp);
1530		if (cbp == NULL) {
1531			for (cbp = bioq_first(&queue); cbp != NULL;
1532			    cbp = bioq_first(&queue)) {
1533				bioq_remove(&queue, cbp);
1534				g_destroy_bio(cbp);
1535			}
1536			if (bp->bio_error == 0)
1537				bp->bio_error = ENOMEM;
1538			g_io_deliver(bp, bp->bio_error);
1539			return;
1540		}
1541		bioq_insert_tail(&queue, cbp);
1542		cbp->bio_done = g_mirror_done;
1543		cbp->bio_caller1 = disk;
1544		cbp->bio_to = disk->d_consumer->provider;
1545		cbp->bio_offset = offset;
1546		cbp->bio_data = data;
1547		cbp->bio_length = MIN(left, slice);
1548		left -= cbp->bio_length;
1549		if (left == 0)
1550			break;
1551		offset += cbp->bio_length;
1552		data += cbp->bio_length;
1553	}
1554	for (cbp = bioq_first(&queue); cbp != NULL; cbp = bioq_first(&queue)) {
1555		bioq_remove(&queue, cbp);
1556		G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1557		disk = cbp->bio_caller1;
1558		cbp->bio_caller1 = NULL;
1559		cp = disk->d_consumer;
1560		KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1561		    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1562		    cp->acr, cp->acw, cp->ace));
1563		disk->d_consumer->index++;
1564		g_io_request(cbp, disk->d_consumer);
1565	}
1566}
1567
1568static void
1569g_mirror_register_request(struct bio *bp)
1570{
1571	struct g_mirror_softc *sc;
1572
1573	sc = bp->bio_to->geom->softc;
1574	switch (bp->bio_cmd) {
1575	case BIO_READ:
1576		switch (sc->sc_balance) {
1577		case G_MIRROR_BALANCE_LOAD:
1578			g_mirror_request_load(sc, bp);
1579			break;
1580		case G_MIRROR_BALANCE_PREFER:
1581			g_mirror_request_prefer(sc, bp);
1582			break;
1583		case G_MIRROR_BALANCE_ROUND_ROBIN:
1584			g_mirror_request_round_robin(sc, bp);
1585			break;
1586		case G_MIRROR_BALANCE_SPLIT:
1587			g_mirror_request_split(sc, bp);
1588			break;
1589		}
1590		return;
1591	case BIO_WRITE:
1592	case BIO_DELETE:
1593	    {
1594		struct g_mirror_disk *disk;
1595		struct g_mirror_disk_sync *sync;
1596		struct bio_queue_head queue;
1597		struct g_consumer *cp;
1598		struct bio *cbp;
1599
1600		/*
1601		 * Delay the request if it is colliding with a synchronization
1602		 * request.
1603		 */
1604		if (g_mirror_sync_collision(sc, bp)) {
1605			g_mirror_regular_delay(sc, bp);
1606			return;
1607		}
1608
1609		if (sc->sc_idle)
1610			g_mirror_unidle(sc);
1611		else
1612			sc->sc_last_write = time_uptime;
1613
1614		/*
1615		 * Allocate all bios before sending any request, so we can
1616		 * return ENOMEM in nice and clean way.
1617		 */
1618		bioq_init(&queue);
1619		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1620			sync = &disk->d_sync;
1621			switch (disk->d_state) {
1622			case G_MIRROR_DISK_STATE_ACTIVE:
1623				break;
1624			case G_MIRROR_DISK_STATE_SYNCHRONIZING:
1625				if (bp->bio_offset >= sync->ds_offset)
1626					continue;
1627				break;
1628			default:
1629				continue;
1630			}
1631			cbp = g_clone_bio(bp);
1632			if (cbp == NULL) {
1633				for (cbp = bioq_first(&queue); cbp != NULL;
1634				    cbp = bioq_first(&queue)) {
1635					bioq_remove(&queue, cbp);
1636					g_destroy_bio(cbp);
1637				}
1638				if (bp->bio_error == 0)
1639					bp->bio_error = ENOMEM;
1640				g_io_deliver(bp, bp->bio_error);
1641				return;
1642			}
1643			bioq_insert_tail(&queue, cbp);
1644			cbp->bio_done = g_mirror_done;
1645			cp = disk->d_consumer;
1646			cbp->bio_caller1 = cp;
1647			cbp->bio_to = cp->provider;
1648			KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1649			    ("Consumer %s not opened (r%dw%de%d).",
1650			    cp->provider->name, cp->acr, cp->acw, cp->ace));
1651		}
1652		for (cbp = bioq_first(&queue); cbp != NULL;
1653		    cbp = bioq_first(&queue)) {
1654			bioq_remove(&queue, cbp);
1655			G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1656			cp = cbp->bio_caller1;
1657			cbp->bio_caller1 = NULL;
1658			cp->index++;
1659			sc->sc_writes++;
1660			g_io_request(cbp, cp);
1661		}
1662		/*
1663		 * Put request onto inflight queue, so we can check if new
1664		 * synchronization requests don't collide with it.
1665		 */
1666		bioq_insert_tail(&sc->sc_inflight, bp);
1667		/*
1668		 * Bump syncid on first write.
1669		 */
1670		if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0) {
1671			sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
1672			g_mirror_bump_syncid(sc);
1673		}
1674		return;
1675	    }
1676	default:
1677		KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
1678		    bp->bio_cmd, sc->sc_name));
1679		break;
1680	}
1681}
1682
1683static int
1684g_mirror_can_destroy(struct g_mirror_softc *sc)
1685{
1686	struct g_geom *gp;
1687	struct g_consumer *cp;
1688
1689	g_topology_assert();
1690	gp = sc->sc_geom;
1691	if (gp->softc == NULL)
1692		return (1);
1693	LIST_FOREACH(cp, &gp->consumer, consumer) {
1694		if (g_mirror_is_busy(sc, cp))
1695			return (0);
1696	}
1697	gp = sc->sc_sync.ds_geom;
1698	LIST_FOREACH(cp, &gp->consumer, consumer) {
1699		if (g_mirror_is_busy(sc, cp))
1700			return (0);
1701	}
1702	G_MIRROR_DEBUG(2, "No I/O requests for %s, it can be destroyed.",
1703	    sc->sc_name);
1704	return (1);
1705}
1706
1707static int
1708g_mirror_try_destroy(struct g_mirror_softc *sc)
1709{
1710
1711	if (sc->sc_rootmount != NULL) {
1712		G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
1713		    sc->sc_rootmount);
1714		root_mount_rel(sc->sc_rootmount);
1715		sc->sc_rootmount = NULL;
1716	}
1717	g_topology_lock();
1718	if (!g_mirror_can_destroy(sc)) {
1719		g_topology_unlock();
1720		return (0);
1721	}
1722	sc->sc_geom->softc = NULL;
1723	sc->sc_sync.ds_geom->softc = NULL;
1724	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_WAIT) != 0) {
1725		g_topology_unlock();
1726		G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1727		    &sc->sc_worker);
1728		/* Unlock sc_lock here, as it can be destroyed after wakeup. */
1729		sx_xunlock(&sc->sc_lock);
1730		wakeup(&sc->sc_worker);
1731		sc->sc_worker = NULL;
1732	} else {
1733		g_topology_unlock();
1734		g_mirror_destroy_device(sc);
1735		free(sc, M_MIRROR);
1736	}
1737	return (1);
1738}
1739
1740/*
1741 * Worker thread.
1742 */
1743static void
1744g_mirror_worker(void *arg)
1745{
1746	struct g_mirror_softc *sc;
1747	struct g_mirror_event *ep;
1748	struct bio *bp;
1749	int timeout;
1750
1751	sc = arg;
1752	thread_lock(curthread);
1753	sched_prio(curthread, PRIBIO);
1754	thread_unlock(curthread);
1755
1756	sx_xlock(&sc->sc_lock);
1757	for (;;) {
1758		G_MIRROR_DEBUG(5, "%s: Let's see...", __func__);
1759		/*
1760		 * First take a look at events.
1761		 * This is important to handle events before any I/O requests.
1762		 */
1763		ep = g_mirror_event_get(sc);
1764		if (ep != NULL) {
1765			g_mirror_event_remove(sc, ep);
1766			if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0) {
1767				/* Update only device status. */
1768				G_MIRROR_DEBUG(3,
1769				    "Running event for device %s.",
1770				    sc->sc_name);
1771				ep->e_error = 0;
1772				g_mirror_update_device(sc, 1);
1773			} else {
1774				/* Update disk status. */
1775				G_MIRROR_DEBUG(3, "Running event for disk %s.",
1776				     g_mirror_get_diskname(ep->e_disk));
1777				ep->e_error = g_mirror_update_disk(ep->e_disk,
1778				    ep->e_state);
1779				if (ep->e_error == 0)
1780					g_mirror_update_device(sc, 0);
1781			}
1782			if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0) {
1783				KASSERT(ep->e_error == 0,
1784				    ("Error cannot be handled."));
1785				g_mirror_event_free(ep);
1786			} else {
1787				ep->e_flags |= G_MIRROR_EVENT_DONE;
1788				G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1789				    ep);
1790				mtx_lock(&sc->sc_events_mtx);
1791				wakeup(ep);
1792				mtx_unlock(&sc->sc_events_mtx);
1793			}
1794			if ((sc->sc_flags &
1795			    G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1796				if (g_mirror_try_destroy(sc)) {
1797					curthread->td_pflags &= ~TDP_GEOM;
1798					G_MIRROR_DEBUG(1, "Thread exiting.");
1799					kproc_exit(0);
1800				}
1801			}
1802			G_MIRROR_DEBUG(5, "%s: I'm here 1.", __func__);
1803			continue;
1804		}
1805		/*
1806		 * Check if we can mark array as CLEAN and if we can't take
1807		 * how much seconds should we wait.
1808		 */
1809		timeout = g_mirror_idle(sc, -1);
1810		/*
1811		 * Now I/O requests.
1812		 */
1813		/* Get first request from the queue. */
1814		mtx_lock(&sc->sc_queue_mtx);
1815		bp = bioq_first(&sc->sc_queue);
1816		if (bp == NULL) {
1817			if ((sc->sc_flags &
1818			    G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1819				mtx_unlock(&sc->sc_queue_mtx);
1820				if (g_mirror_try_destroy(sc)) {
1821					curthread->td_pflags &= ~TDP_GEOM;
1822					G_MIRROR_DEBUG(1, "Thread exiting.");
1823					kproc_exit(0);
1824				}
1825				mtx_lock(&sc->sc_queue_mtx);
1826			}
1827			sx_xunlock(&sc->sc_lock);
1828			/*
1829			 * XXX: We can miss an event here, because an event
1830			 *      can be added without sx-device-lock and without
1831			 *      mtx-queue-lock. Maybe I should just stop using
1832			 *      dedicated mutex for events synchronization and
1833			 *      stick with the queue lock?
1834			 *      The event will hang here until next I/O request
1835			 *      or next event is received.
1836			 */
1837			MSLEEP(sc, &sc->sc_queue_mtx, PRIBIO | PDROP, "m:w1",
1838			    timeout * hz);
1839			sx_xlock(&sc->sc_lock);
1840			G_MIRROR_DEBUG(5, "%s: I'm here 4.", __func__);
1841			continue;
1842		}
1843		bioq_remove(&sc->sc_queue, bp);
1844		mtx_unlock(&sc->sc_queue_mtx);
1845
1846		if (bp->bio_from->geom == sc->sc_sync.ds_geom &&
1847		    (bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0) {
1848			g_mirror_sync_request(bp);	/* READ */
1849		} else if (bp->bio_to != sc->sc_provider) {
1850			if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_REGULAR) != 0)
1851				g_mirror_regular_request(bp);
1852			else if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0)
1853				g_mirror_sync_request(bp);	/* WRITE */
1854			else {
1855				KASSERT(0,
1856				    ("Invalid request cflags=0x%hhx to=%s.",
1857				    bp->bio_cflags, bp->bio_to->name));
1858			}
1859		} else {
1860			g_mirror_register_request(bp);
1861		}
1862		G_MIRROR_DEBUG(5, "%s: I'm here 9.", __func__);
1863	}
1864}
1865
1866static void
1867g_mirror_update_idle(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
1868{
1869
1870	sx_assert(&sc->sc_lock, SX_LOCKED);
1871
1872	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
1873		return;
1874	if (!sc->sc_idle && (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) == 0) {
1875		G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as dirty.",
1876		    g_mirror_get_diskname(disk), sc->sc_name);
1877		disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
1878	} else if (sc->sc_idle &&
1879	    (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
1880		G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as clean.",
1881		    g_mirror_get_diskname(disk), sc->sc_name);
1882		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
1883	}
1884}
1885
1886static void
1887g_mirror_sync_start(struct g_mirror_disk *disk)
1888{
1889	struct g_mirror_softc *sc;
1890	struct g_consumer *cp;
1891	struct bio *bp;
1892	int error, i;
1893
1894	g_topology_assert_not();
1895	sc = disk->d_softc;
1896	sx_assert(&sc->sc_lock, SX_LOCKED);
1897
1898	KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
1899	    ("Disk %s is not marked for synchronization.",
1900	    g_mirror_get_diskname(disk)));
1901	KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
1902	    ("Device not in RUNNING state (%s, %u).", sc->sc_name,
1903	    sc->sc_state));
1904
1905	sx_xunlock(&sc->sc_lock);
1906	g_topology_lock();
1907	cp = g_new_consumer(sc->sc_sync.ds_geom);
1908	error = g_attach(cp, sc->sc_provider);
1909	KASSERT(error == 0,
1910	    ("Cannot attach to %s (error=%d).", sc->sc_name, error));
1911	error = g_access(cp, 1, 0, 0);
1912	KASSERT(error == 0, ("Cannot open %s (error=%d).", sc->sc_name, error));
1913	g_topology_unlock();
1914	sx_xlock(&sc->sc_lock);
1915
1916	G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s.", sc->sc_name,
1917	    g_mirror_get_diskname(disk));
1918	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) == 0)
1919		disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
1920	KASSERT(disk->d_sync.ds_consumer == NULL,
1921	    ("Sync consumer already exists (device=%s, disk=%s).",
1922	    sc->sc_name, g_mirror_get_diskname(disk)));
1923
1924	disk->d_sync.ds_consumer = cp;
1925	disk->d_sync.ds_consumer->private = disk;
1926	disk->d_sync.ds_consumer->index = 0;
1927
1928	/*
1929	 * Allocate memory for synchronization bios and initialize them.
1930	 */
1931	disk->d_sync.ds_bios = malloc(sizeof(struct bio *) * g_mirror_syncreqs,
1932	    M_MIRROR, M_WAITOK);
1933	for (i = 0; i < g_mirror_syncreqs; i++) {
1934		bp = g_alloc_bio();
1935		disk->d_sync.ds_bios[i] = bp;
1936		bp->bio_parent = NULL;
1937		bp->bio_cmd = BIO_READ;
1938		bp->bio_data = malloc(MAXPHYS, M_MIRROR, M_WAITOK);
1939		bp->bio_cflags = 0;
1940		bp->bio_offset = disk->d_sync.ds_offset;
1941		bp->bio_length = MIN(MAXPHYS, sc->sc_mediasize - bp->bio_offset);
1942		disk->d_sync.ds_offset += bp->bio_length;
1943		bp->bio_done = g_mirror_sync_done;
1944		bp->bio_from = disk->d_sync.ds_consumer;
1945		bp->bio_to = sc->sc_provider;
1946		bp->bio_caller1 = (void *)(uintptr_t)i;
1947	}
1948
1949	/* Increase the number of disks in SYNCHRONIZING state. */
1950	sc->sc_sync.ds_ndisks++;
1951	/* Set the number of in-flight synchronization requests. */
1952	disk->d_sync.ds_inflight = g_mirror_syncreqs;
1953
1954	/*
1955	 * Fire off first synchronization requests.
1956	 */
1957	for (i = 0; i < g_mirror_syncreqs; i++) {
1958		bp = disk->d_sync.ds_bios[i];
1959		G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
1960		disk->d_sync.ds_consumer->index++;
1961		/*
1962		 * Delay the request if it is colliding with a regular request.
1963		 */
1964		if (g_mirror_regular_collision(sc, bp))
1965			g_mirror_sync_delay(sc, bp);
1966		else
1967			g_io_request(bp, disk->d_sync.ds_consumer);
1968	}
1969}
1970
1971/*
1972 * Stop synchronization process.
1973 * type: 0 - synchronization finished
1974 *       1 - synchronization stopped
1975 */
1976static void
1977g_mirror_sync_stop(struct g_mirror_disk *disk, int type)
1978{
1979	struct g_mirror_softc *sc;
1980	struct g_consumer *cp;
1981
1982	g_topology_assert_not();
1983	sc = disk->d_softc;
1984	sx_assert(&sc->sc_lock, SX_LOCKED);
1985
1986	KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
1987	    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
1988	    g_mirror_disk_state2str(disk->d_state)));
1989	if (disk->d_sync.ds_consumer == NULL)
1990		return;
1991
1992	if (type == 0) {
1993		G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s finished.",
1994		    sc->sc_name, g_mirror_get_diskname(disk));
1995	} else /* if (type == 1) */ {
1996		G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s stopped.",
1997		    sc->sc_name, g_mirror_get_diskname(disk));
1998	}
1999	free(disk->d_sync.ds_bios, M_MIRROR);
2000	disk->d_sync.ds_bios = NULL;
2001	cp = disk->d_sync.ds_consumer;
2002	disk->d_sync.ds_consumer = NULL;
2003	disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2004	sc->sc_sync.ds_ndisks--;
2005	sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
2006	g_topology_lock();
2007	g_mirror_kill_consumer(sc, cp);
2008	g_topology_unlock();
2009	sx_xlock(&sc->sc_lock);
2010}
2011
2012static void
2013g_mirror_launch_provider(struct g_mirror_softc *sc)
2014{
2015	struct g_mirror_disk *disk;
2016	struct g_provider *pp;
2017
2018	sx_assert(&sc->sc_lock, SX_LOCKED);
2019
2020	g_topology_lock();
2021	pp = g_new_providerf(sc->sc_geom, "mirror/%s", sc->sc_name);
2022	pp->mediasize = sc->sc_mediasize;
2023	pp->sectorsize = sc->sc_sectorsize;
2024	pp->stripesize = 0;
2025	pp->stripeoffset = 0;
2026	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2027		if (disk->d_consumer && disk->d_consumer->provider &&
2028		    disk->d_consumer->provider->stripesize > pp->stripesize) {
2029			pp->stripesize = disk->d_consumer->provider->stripesize;
2030			pp->stripeoffset = disk->d_consumer->provider->stripeoffset;
2031		}
2032	}
2033	sc->sc_provider = pp;
2034	g_error_provider(pp, 0);
2035	g_topology_unlock();
2036	G_MIRROR_DEBUG(0, "Device %s launched (%u/%u).", pp->name,
2037	    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE), sc->sc_ndisks);
2038	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2039		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2040			g_mirror_sync_start(disk);
2041	}
2042}
2043
2044static void
2045g_mirror_destroy_provider(struct g_mirror_softc *sc)
2046{
2047	struct g_mirror_disk *disk;
2048	struct bio *bp;
2049
2050	g_topology_assert_not();
2051	KASSERT(sc->sc_provider != NULL, ("NULL provider (device=%s).",
2052	    sc->sc_name));
2053
2054	g_topology_lock();
2055	g_error_provider(sc->sc_provider, ENXIO);
2056	mtx_lock(&sc->sc_queue_mtx);
2057	while ((bp = bioq_first(&sc->sc_queue)) != NULL) {
2058		bioq_remove(&sc->sc_queue, bp);
2059		g_io_deliver(bp, ENXIO);
2060	}
2061	mtx_unlock(&sc->sc_queue_mtx);
2062	G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.", sc->sc_name,
2063	    sc->sc_provider->name);
2064	sc->sc_provider->flags |= G_PF_WITHER;
2065	g_orphan_provider(sc->sc_provider, ENXIO);
2066	g_topology_unlock();
2067	sc->sc_provider = NULL;
2068	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2069		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2070			g_mirror_sync_stop(disk, 1);
2071	}
2072}
2073
2074static void
2075g_mirror_go(void *arg)
2076{
2077	struct g_mirror_softc *sc;
2078
2079	sc = arg;
2080	G_MIRROR_DEBUG(0, "Force device %s start due to timeout.", sc->sc_name);
2081	g_mirror_event_send(sc, 0,
2082	    G_MIRROR_EVENT_DONTWAIT | G_MIRROR_EVENT_DEVICE);
2083}
2084
2085static u_int
2086g_mirror_determine_state(struct g_mirror_disk *disk)
2087{
2088	struct g_mirror_softc *sc;
2089	u_int state;
2090
2091	sc = disk->d_softc;
2092	if (sc->sc_syncid == disk->d_sync.ds_syncid) {
2093		if ((disk->d_flags &
2094		    G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2095			/* Disk does not need synchronization. */
2096			state = G_MIRROR_DISK_STATE_ACTIVE;
2097		} else {
2098			if ((sc->sc_flags &
2099			     G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2100			    (disk->d_flags &
2101			     G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2102				/*
2103				 * We can start synchronization from
2104				 * the stored offset.
2105				 */
2106				state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2107			} else {
2108				state = G_MIRROR_DISK_STATE_STALE;
2109			}
2110		}
2111	} else if (disk->d_sync.ds_syncid < sc->sc_syncid) {
2112		/*
2113		 * Reset all synchronization data for this disk,
2114		 * because if it even was synchronized, it was
2115		 * synchronized to disks with different syncid.
2116		 */
2117		disk->d_flags |= G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2118		disk->d_sync.ds_offset = 0;
2119		disk->d_sync.ds_offset_done = 0;
2120		disk->d_sync.ds_syncid = sc->sc_syncid;
2121		if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2122		    (disk->d_flags & G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2123			state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2124		} else {
2125			state = G_MIRROR_DISK_STATE_STALE;
2126		}
2127	} else /* if (sc->sc_syncid < disk->d_sync.ds_syncid) */ {
2128		/*
2129		 * Not good, NOT GOOD!
2130		 * It means that mirror was started on stale disks
2131		 * and more fresh disk just arrive.
2132		 * If there were writes, mirror is broken, sorry.
2133		 * I think the best choice here is don't touch
2134		 * this disk and inform the user loudly.
2135		 */
2136		G_MIRROR_DEBUG(0, "Device %s was started before the freshest "
2137		    "disk (%s) arrives!! It will not be connected to the "
2138		    "running device.", sc->sc_name,
2139		    g_mirror_get_diskname(disk));
2140		g_mirror_destroy_disk(disk);
2141		state = G_MIRROR_DISK_STATE_NONE;
2142		/* Return immediately, because disk was destroyed. */
2143		return (state);
2144	}
2145	G_MIRROR_DEBUG(3, "State for %s disk: %s.",
2146	    g_mirror_get_diskname(disk), g_mirror_disk_state2str(state));
2147	return (state);
2148}
2149
2150/*
2151 * Update device state.
2152 */
2153static void
2154g_mirror_update_device(struct g_mirror_softc *sc, boolean_t force)
2155{
2156	struct g_mirror_disk *disk;
2157	u_int state;
2158
2159	sx_assert(&sc->sc_lock, SX_XLOCKED);
2160
2161	switch (sc->sc_state) {
2162	case G_MIRROR_DEVICE_STATE_STARTING:
2163	    {
2164		struct g_mirror_disk *pdisk, *tdisk;
2165		u_int dirty, ndisks, genid, syncid;
2166
2167		KASSERT(sc->sc_provider == NULL,
2168		    ("Non-NULL provider in STARTING state (%s).", sc->sc_name));
2169		/*
2170		 * Are we ready? We are, if all disks are connected or
2171		 * if we have any disks and 'force' is true.
2172		 */
2173		ndisks = g_mirror_ndisks(sc, -1);
2174		if (sc->sc_ndisks == ndisks || (force && ndisks > 0)) {
2175			;
2176		} else if (ndisks == 0) {
2177			/*
2178			 * Disks went down in starting phase, so destroy
2179			 * device.
2180			 */
2181			callout_drain(&sc->sc_callout);
2182			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2183			G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
2184			    sc->sc_rootmount);
2185			root_mount_rel(sc->sc_rootmount);
2186			sc->sc_rootmount = NULL;
2187			return;
2188		} else {
2189			return;
2190		}
2191
2192		/*
2193		 * Activate all disks with the biggest syncid.
2194		 */
2195		if (force) {
2196			/*
2197			 * If 'force' is true, we have been called due to
2198			 * timeout, so don't bother canceling timeout.
2199			 */
2200			ndisks = 0;
2201			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2202				if ((disk->d_flags &
2203				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2204					ndisks++;
2205				}
2206			}
2207			if (ndisks == 0) {
2208				/* No valid disks found, destroy device. */
2209				sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2210				G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2211				    __LINE__, sc->sc_rootmount);
2212				root_mount_rel(sc->sc_rootmount);
2213				sc->sc_rootmount = NULL;
2214				return;
2215			}
2216		} else {
2217			/* Cancel timeout. */
2218			callout_drain(&sc->sc_callout);
2219		}
2220
2221		/*
2222		 * Find the biggest genid.
2223		 */
2224		genid = 0;
2225		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2226			if (disk->d_genid > genid)
2227				genid = disk->d_genid;
2228		}
2229		sc->sc_genid = genid;
2230		/*
2231		 * Remove all disks without the biggest genid.
2232		 */
2233		LIST_FOREACH_SAFE(disk, &sc->sc_disks, d_next, tdisk) {
2234			if (disk->d_genid < genid) {
2235				G_MIRROR_DEBUG(0,
2236				    "Component %s (device %s) broken, skipping.",
2237				    g_mirror_get_diskname(disk), sc->sc_name);
2238				g_mirror_destroy_disk(disk);
2239			}
2240		}
2241
2242		/*
2243		 * Find the biggest syncid.
2244		 */
2245		syncid = 0;
2246		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2247			if (disk->d_sync.ds_syncid > syncid)
2248				syncid = disk->d_sync.ds_syncid;
2249		}
2250
2251		/*
2252		 * Here we need to look for dirty disks and if all disks
2253		 * with the biggest syncid are dirty, we have to choose
2254		 * one with the biggest priority and rebuild the rest.
2255		 */
2256		/*
2257		 * Find the number of dirty disks with the biggest syncid.
2258		 * Find the number of disks with the biggest syncid.
2259		 * While here, find a disk with the biggest priority.
2260		 */
2261		dirty = ndisks = 0;
2262		pdisk = NULL;
2263		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2264			if (disk->d_sync.ds_syncid != syncid)
2265				continue;
2266			if ((disk->d_flags &
2267			    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2268				continue;
2269			}
2270			ndisks++;
2271			if ((disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
2272				dirty++;
2273				if (pdisk == NULL ||
2274				    pdisk->d_priority < disk->d_priority) {
2275					pdisk = disk;
2276				}
2277			}
2278		}
2279		if (dirty == 0) {
2280			/* No dirty disks at all, great. */
2281		} else if (dirty == ndisks) {
2282			/*
2283			 * Force synchronization for all dirty disks except one
2284			 * with the biggest priority.
2285			 */
2286			KASSERT(pdisk != NULL, ("pdisk == NULL"));
2287			G_MIRROR_DEBUG(1, "Using disk %s (device %s) as a "
2288			    "master disk for synchronization.",
2289			    g_mirror_get_diskname(pdisk), sc->sc_name);
2290			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2291				if (disk->d_sync.ds_syncid != syncid)
2292					continue;
2293				if ((disk->d_flags &
2294				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2295					continue;
2296				}
2297				KASSERT((disk->d_flags &
2298				    G_MIRROR_DISK_FLAG_DIRTY) != 0,
2299				    ("Disk %s isn't marked as dirty.",
2300				    g_mirror_get_diskname(disk)));
2301				/* Skip the disk with the biggest priority. */
2302				if (disk == pdisk)
2303					continue;
2304				disk->d_sync.ds_syncid = 0;
2305			}
2306		} else if (dirty < ndisks) {
2307			/*
2308			 * Force synchronization for all dirty disks.
2309			 * We have some non-dirty disks.
2310			 */
2311			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2312				if (disk->d_sync.ds_syncid != syncid)
2313					continue;
2314				if ((disk->d_flags &
2315				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2316					continue;
2317				}
2318				if ((disk->d_flags &
2319				    G_MIRROR_DISK_FLAG_DIRTY) == 0) {
2320					continue;
2321				}
2322				disk->d_sync.ds_syncid = 0;
2323			}
2324		}
2325
2326		/* Reset hint. */
2327		sc->sc_hint = NULL;
2328		sc->sc_syncid = syncid;
2329		if (force) {
2330			/* Remember to bump syncid on first write. */
2331			sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2332		}
2333		state = G_MIRROR_DEVICE_STATE_RUNNING;
2334		G_MIRROR_DEBUG(1, "Device %s state changed from %s to %s.",
2335		    sc->sc_name, g_mirror_device_state2str(sc->sc_state),
2336		    g_mirror_device_state2str(state));
2337		sc->sc_state = state;
2338		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2339			state = g_mirror_determine_state(disk);
2340			g_mirror_event_send(disk, state,
2341			    G_MIRROR_EVENT_DONTWAIT);
2342			if (state == G_MIRROR_DISK_STATE_STALE)
2343				sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2344		}
2345		break;
2346	    }
2347	case G_MIRROR_DEVICE_STATE_RUNNING:
2348		if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 0 &&
2349		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2350			/*
2351			 * No active disks or no disks at all,
2352			 * so destroy device.
2353			 */
2354			if (sc->sc_provider != NULL)
2355				g_mirror_destroy_provider(sc);
2356			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2357			break;
2358		} else if (g_mirror_ndisks(sc,
2359		    G_MIRROR_DISK_STATE_ACTIVE) > 0 &&
2360		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2361			/*
2362			 * We have active disks, launch provider if it doesn't
2363			 * exist.
2364			 */
2365			if (sc->sc_provider == NULL)
2366				g_mirror_launch_provider(sc);
2367			if (sc->sc_rootmount != NULL) {
2368				G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2369				    __LINE__, sc->sc_rootmount);
2370				root_mount_rel(sc->sc_rootmount);
2371				sc->sc_rootmount = NULL;
2372			}
2373		}
2374		/*
2375		 * Genid should be bumped immediately, so do it here.
2376		 */
2377		if ((sc->sc_bump_id & G_MIRROR_BUMP_GENID) != 0) {
2378			sc->sc_bump_id &= ~G_MIRROR_BUMP_GENID;
2379			g_mirror_bump_genid(sc);
2380		}
2381		break;
2382	default:
2383		KASSERT(1 == 0, ("Wrong device state (%s, %s).",
2384		    sc->sc_name, g_mirror_device_state2str(sc->sc_state)));
2385		break;
2386	}
2387}
2388
2389/*
2390 * Update disk state and device state if needed.
2391 */
2392#define	DISK_STATE_CHANGED()	G_MIRROR_DEBUG(1,			\
2393	"Disk %s state changed from %s to %s (device %s).",		\
2394	g_mirror_get_diskname(disk),					\
2395	g_mirror_disk_state2str(disk->d_state),				\
2396	g_mirror_disk_state2str(state), sc->sc_name)
2397static int
2398g_mirror_update_disk(struct g_mirror_disk *disk, u_int state)
2399{
2400	struct g_mirror_softc *sc;
2401
2402	sc = disk->d_softc;
2403	sx_assert(&sc->sc_lock, SX_XLOCKED);
2404
2405again:
2406	G_MIRROR_DEBUG(3, "Changing disk %s state from %s to %s.",
2407	    g_mirror_get_diskname(disk), g_mirror_disk_state2str(disk->d_state),
2408	    g_mirror_disk_state2str(state));
2409	switch (state) {
2410	case G_MIRROR_DISK_STATE_NEW:
2411		/*
2412		 * Possible scenarios:
2413		 * 1. New disk arrive.
2414		 */
2415		/* Previous state should be NONE. */
2416		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NONE,
2417		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2418		    g_mirror_disk_state2str(disk->d_state)));
2419		DISK_STATE_CHANGED();
2420
2421		disk->d_state = state;
2422		if (LIST_EMPTY(&sc->sc_disks))
2423			LIST_INSERT_HEAD(&sc->sc_disks, disk, d_next);
2424		else {
2425			struct g_mirror_disk *dp;
2426
2427			LIST_FOREACH(dp, &sc->sc_disks, d_next) {
2428				if (disk->d_priority >= dp->d_priority) {
2429					LIST_INSERT_BEFORE(dp, disk, d_next);
2430					dp = NULL;
2431					break;
2432				}
2433				if (LIST_NEXT(dp, d_next) == NULL)
2434					break;
2435			}
2436			if (dp != NULL)
2437				LIST_INSERT_AFTER(dp, disk, d_next);
2438		}
2439		G_MIRROR_DEBUG(1, "Device %s: provider %s detected.",
2440		    sc->sc_name, g_mirror_get_diskname(disk));
2441		if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
2442			break;
2443		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2444		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2445		    g_mirror_device_state2str(sc->sc_state),
2446		    g_mirror_get_diskname(disk),
2447		    g_mirror_disk_state2str(disk->d_state)));
2448		state = g_mirror_determine_state(disk);
2449		if (state != G_MIRROR_DISK_STATE_NONE)
2450			goto again;
2451		break;
2452	case G_MIRROR_DISK_STATE_ACTIVE:
2453		/*
2454		 * Possible scenarios:
2455		 * 1. New disk does not need synchronization.
2456		 * 2. Synchronization process finished successfully.
2457		 */
2458		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2459		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2460		    g_mirror_device_state2str(sc->sc_state),
2461		    g_mirror_get_diskname(disk),
2462		    g_mirror_disk_state2str(disk->d_state)));
2463		/* Previous state should be NEW or SYNCHRONIZING. */
2464		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW ||
2465		    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2466		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2467		    g_mirror_disk_state2str(disk->d_state)));
2468		DISK_STATE_CHANGED();
2469
2470		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
2471			disk->d_flags &= ~G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2472			disk->d_flags &= ~G_MIRROR_DISK_FLAG_FORCE_SYNC;
2473			g_mirror_sync_stop(disk, 0);
2474		}
2475		disk->d_state = state;
2476		disk->d_sync.ds_offset = 0;
2477		disk->d_sync.ds_offset_done = 0;
2478		g_mirror_update_idle(sc, disk);
2479		g_mirror_update_metadata(disk);
2480		G_MIRROR_DEBUG(1, "Device %s: provider %s activated.",
2481		    sc->sc_name, g_mirror_get_diskname(disk));
2482		break;
2483	case G_MIRROR_DISK_STATE_STALE:
2484		/*
2485		 * Possible scenarios:
2486		 * 1. Stale disk was connected.
2487		 */
2488		/* Previous state should be NEW. */
2489		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2490		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2491		    g_mirror_disk_state2str(disk->d_state)));
2492		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2493		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2494		    g_mirror_device_state2str(sc->sc_state),
2495		    g_mirror_get_diskname(disk),
2496		    g_mirror_disk_state2str(disk->d_state)));
2497		/*
2498		 * STALE state is only possible if device is marked
2499		 * NOAUTOSYNC.
2500		 */
2501		KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0,
2502		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2503		    g_mirror_device_state2str(sc->sc_state),
2504		    g_mirror_get_diskname(disk),
2505		    g_mirror_disk_state2str(disk->d_state)));
2506		DISK_STATE_CHANGED();
2507
2508		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2509		disk->d_state = state;
2510		g_mirror_update_metadata(disk);
2511		G_MIRROR_DEBUG(0, "Device %s: provider %s is stale.",
2512		    sc->sc_name, g_mirror_get_diskname(disk));
2513		break;
2514	case G_MIRROR_DISK_STATE_SYNCHRONIZING:
2515		/*
2516		 * Possible scenarios:
2517		 * 1. Disk which needs synchronization was connected.
2518		 */
2519		/* Previous state should be NEW. */
2520		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2521		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2522		    g_mirror_disk_state2str(disk->d_state)));
2523		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2524		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2525		    g_mirror_device_state2str(sc->sc_state),
2526		    g_mirror_get_diskname(disk),
2527		    g_mirror_disk_state2str(disk->d_state)));
2528		DISK_STATE_CHANGED();
2529
2530		if (disk->d_state == G_MIRROR_DISK_STATE_NEW)
2531			disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2532		disk->d_state = state;
2533		if (sc->sc_provider != NULL) {
2534			g_mirror_sync_start(disk);
2535			g_mirror_update_metadata(disk);
2536		}
2537		break;
2538	case G_MIRROR_DISK_STATE_DISCONNECTED:
2539		/*
2540		 * Possible scenarios:
2541		 * 1. Device wasn't running yet, but disk disappear.
2542		 * 2. Disk was active and disapppear.
2543		 * 3. Disk disappear during synchronization process.
2544		 */
2545		if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING) {
2546			/*
2547			 * Previous state should be ACTIVE, STALE or
2548			 * SYNCHRONIZING.
2549			 */
2550			KASSERT(disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
2551			    disk->d_state == G_MIRROR_DISK_STATE_STALE ||
2552			    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2553			    ("Wrong disk state (%s, %s).",
2554			    g_mirror_get_diskname(disk),
2555			    g_mirror_disk_state2str(disk->d_state)));
2556		} else if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING) {
2557			/* Previous state should be NEW. */
2558			KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2559			    ("Wrong disk state (%s, %s).",
2560			    g_mirror_get_diskname(disk),
2561			    g_mirror_disk_state2str(disk->d_state)));
2562			/*
2563			 * Reset bumping syncid if disk disappeared in STARTING
2564			 * state.
2565			 */
2566			if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0)
2567				sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
2568#ifdef	INVARIANTS
2569		} else {
2570			KASSERT(1 == 0, ("Wrong device state (%s, %s, %s, %s).",
2571			    sc->sc_name,
2572			    g_mirror_device_state2str(sc->sc_state),
2573			    g_mirror_get_diskname(disk),
2574			    g_mirror_disk_state2str(disk->d_state)));
2575#endif
2576		}
2577		DISK_STATE_CHANGED();
2578		G_MIRROR_DEBUG(0, "Device %s: provider %s disconnected.",
2579		    sc->sc_name, g_mirror_get_diskname(disk));
2580
2581		g_mirror_destroy_disk(disk);
2582		break;
2583	case G_MIRROR_DISK_STATE_DESTROY:
2584	    {
2585		int error;
2586
2587		error = g_mirror_clear_metadata(disk);
2588		if (error != 0)
2589			return (error);
2590		DISK_STATE_CHANGED();
2591		G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.",
2592		    sc->sc_name, g_mirror_get_diskname(disk));
2593
2594		g_mirror_destroy_disk(disk);
2595		sc->sc_ndisks--;
2596		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2597			g_mirror_update_metadata(disk);
2598		}
2599		break;
2600	    }
2601	default:
2602		KASSERT(1 == 0, ("Unknown state (%u).", state));
2603		break;
2604	}
2605	return (0);
2606}
2607#undef	DISK_STATE_CHANGED
2608
2609int
2610g_mirror_read_metadata(struct g_consumer *cp, struct g_mirror_metadata *md)
2611{
2612	struct g_provider *pp;
2613	u_char *buf;
2614	int error;
2615
2616	g_topology_assert();
2617
2618	error = g_access(cp, 1, 0, 0);
2619	if (error != 0)
2620		return (error);
2621	pp = cp->provider;
2622	g_topology_unlock();
2623	/* Metadata are stored on last sector. */
2624	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
2625	    &error);
2626	g_topology_lock();
2627	g_access(cp, -1, 0, 0);
2628	if (buf == NULL) {
2629		G_MIRROR_DEBUG(1, "Cannot read metadata from %s (error=%d).",
2630		    cp->provider->name, error);
2631		return (error);
2632	}
2633
2634	/* Decode metadata. */
2635	error = mirror_metadata_decode(buf, md);
2636	g_free(buf);
2637	if (strcmp(md->md_magic, G_MIRROR_MAGIC) != 0)
2638		return (EINVAL);
2639	if (md->md_version > G_MIRROR_VERSION) {
2640		G_MIRROR_DEBUG(0,
2641		    "Kernel module is too old to handle metadata from %s.",
2642		    cp->provider->name);
2643		return (EINVAL);
2644	}
2645	if (error != 0) {
2646		G_MIRROR_DEBUG(1, "MD5 metadata hash mismatch for provider %s.",
2647		    cp->provider->name);
2648		return (error);
2649	}
2650
2651	return (0);
2652}
2653
2654static int
2655g_mirror_check_metadata(struct g_mirror_softc *sc, struct g_provider *pp,
2656    struct g_mirror_metadata *md)
2657{
2658
2659	if (g_mirror_id2disk(sc, md->md_did) != NULL) {
2660		G_MIRROR_DEBUG(1, "Disk %s (id=%u) already exists, skipping.",
2661		    pp->name, md->md_did);
2662		return (EEXIST);
2663	}
2664	if (md->md_all != sc->sc_ndisks) {
2665		G_MIRROR_DEBUG(1,
2666		    "Invalid '%s' field on disk %s (device %s), skipping.",
2667		    "md_all", pp->name, sc->sc_name);
2668		return (EINVAL);
2669	}
2670	if (md->md_slice != sc->sc_slice) {
2671		G_MIRROR_DEBUG(1,
2672		    "Invalid '%s' field on disk %s (device %s), skipping.",
2673		    "md_slice", pp->name, sc->sc_name);
2674		return (EINVAL);
2675	}
2676	if (md->md_balance != sc->sc_balance) {
2677		G_MIRROR_DEBUG(1,
2678		    "Invalid '%s' field on disk %s (device %s), skipping.",
2679		    "md_balance", pp->name, sc->sc_name);
2680		return (EINVAL);
2681	}
2682	if (md->md_mediasize != sc->sc_mediasize) {
2683		G_MIRROR_DEBUG(1,
2684		    "Invalid '%s' field on disk %s (device %s), skipping.",
2685		    "md_mediasize", pp->name, sc->sc_name);
2686		return (EINVAL);
2687	}
2688	if (sc->sc_mediasize > pp->mediasize) {
2689		G_MIRROR_DEBUG(1,
2690		    "Invalid size of disk %s (device %s), skipping.", pp->name,
2691		    sc->sc_name);
2692		return (EINVAL);
2693	}
2694	if (md->md_sectorsize != sc->sc_sectorsize) {
2695		G_MIRROR_DEBUG(1,
2696		    "Invalid '%s' field on disk %s (device %s), skipping.",
2697		    "md_sectorsize", pp->name, sc->sc_name);
2698		return (EINVAL);
2699	}
2700	if ((sc->sc_sectorsize % pp->sectorsize) != 0) {
2701		G_MIRROR_DEBUG(1,
2702		    "Invalid sector size of disk %s (device %s), skipping.",
2703		    pp->name, sc->sc_name);
2704		return (EINVAL);
2705	}
2706	if ((md->md_mflags & ~G_MIRROR_DEVICE_FLAG_MASK) != 0) {
2707		G_MIRROR_DEBUG(1,
2708		    "Invalid device flags on disk %s (device %s), skipping.",
2709		    pp->name, sc->sc_name);
2710		return (EINVAL);
2711	}
2712	if ((md->md_dflags & ~G_MIRROR_DISK_FLAG_MASK) != 0) {
2713		G_MIRROR_DEBUG(1,
2714		    "Invalid disk flags on disk %s (device %s), skipping.",
2715		    pp->name, sc->sc_name);
2716		return (EINVAL);
2717	}
2718	return (0);
2719}
2720
2721int
2722g_mirror_add_disk(struct g_mirror_softc *sc, struct g_provider *pp,
2723    struct g_mirror_metadata *md)
2724{
2725	struct g_mirror_disk *disk;
2726	int error;
2727
2728	g_topology_assert_not();
2729	G_MIRROR_DEBUG(2, "Adding disk %s.", pp->name);
2730
2731	error = g_mirror_check_metadata(sc, pp, md);
2732	if (error != 0)
2733		return (error);
2734	if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING &&
2735	    md->md_genid < sc->sc_genid) {
2736		G_MIRROR_DEBUG(0, "Component %s (device %s) broken, skipping.",
2737		    pp->name, sc->sc_name);
2738		return (EINVAL);
2739	}
2740	disk = g_mirror_init_disk(sc, pp, md, &error);
2741	if (disk == NULL)
2742		return (error);
2743	error = g_mirror_event_send(disk, G_MIRROR_DISK_STATE_NEW,
2744	    G_MIRROR_EVENT_WAIT);
2745	if (error != 0)
2746		return (error);
2747	if (md->md_version < G_MIRROR_VERSION) {
2748		G_MIRROR_DEBUG(0, "Upgrading metadata on %s (v%d->v%d).",
2749		    pp->name, md->md_version, G_MIRROR_VERSION);
2750		g_mirror_update_metadata(disk);
2751	}
2752	return (0);
2753}
2754
2755static void
2756g_mirror_destroy_delayed(void *arg, int flag)
2757{
2758	struct g_mirror_softc *sc;
2759	int error;
2760
2761	if (flag == EV_CANCEL) {
2762		G_MIRROR_DEBUG(1, "Destroying canceled.");
2763		return;
2764	}
2765	sc = arg;
2766	g_topology_unlock();
2767	sx_xlock(&sc->sc_lock);
2768	KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) == 0,
2769	    ("DESTROY flag set on %s.", sc->sc_name));
2770	KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROYING) != 0,
2771	    ("DESTROYING flag not set on %s.", sc->sc_name));
2772	G_MIRROR_DEBUG(1, "Destroying %s (delayed).", sc->sc_name);
2773	error = g_mirror_destroy(sc, G_MIRROR_DESTROY_SOFT);
2774	if (error != 0) {
2775		G_MIRROR_DEBUG(0, "Cannot destroy %s.", sc->sc_name);
2776		sx_xunlock(&sc->sc_lock);
2777	}
2778	g_topology_lock();
2779}
2780
2781static int
2782g_mirror_access(struct g_provider *pp, int acr, int acw, int ace)
2783{
2784	struct g_mirror_softc *sc;
2785	int dcr, dcw, dce, error = 0;
2786
2787	g_topology_assert();
2788	G_MIRROR_DEBUG(2, "Access request for %s: r%dw%de%d.", pp->name, acr,
2789	    acw, ace);
2790
2791	sc = pp->geom->softc;
2792	if (sc == NULL && acr <= 0 && acw <= 0 && ace <= 0)
2793		return (0);
2794	KASSERT(sc != NULL, ("NULL softc (provider=%s).", pp->name));
2795
2796	dcr = pp->acr + acr;
2797	dcw = pp->acw + acw;
2798	dce = pp->ace + ace;
2799
2800	g_topology_unlock();
2801	sx_xlock(&sc->sc_lock);
2802	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0 ||
2803	    LIST_EMPTY(&sc->sc_disks)) {
2804		if (acr > 0 || acw > 0 || ace > 0)
2805			error = ENXIO;
2806		goto end;
2807	}
2808	if (dcw == 0 && !sc->sc_idle)
2809		g_mirror_idle(sc, dcw);
2810	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROYING) != 0) {
2811		if (acr > 0 || acw > 0 || ace > 0) {
2812			error = ENXIO;
2813			goto end;
2814		}
2815		if (dcr == 0 && dcw == 0 && dce == 0) {
2816			g_post_event(g_mirror_destroy_delayed, sc, M_WAITOK,
2817			    sc, NULL);
2818		}
2819	}
2820end:
2821	sx_xunlock(&sc->sc_lock);
2822	g_topology_lock();
2823	return (error);
2824}
2825
2826static struct g_geom *
2827g_mirror_create(struct g_class *mp, const struct g_mirror_metadata *md)
2828{
2829	struct g_mirror_softc *sc;
2830	struct g_geom *gp;
2831	int error, timeout;
2832
2833	g_topology_assert();
2834	G_MIRROR_DEBUG(1, "Creating device %s (id=%u).", md->md_name,
2835	    md->md_mid);
2836
2837	/* One disk is minimum. */
2838	if (md->md_all < 1)
2839		return (NULL);
2840	/*
2841	 * Action geom.
2842	 */
2843	gp = g_new_geomf(mp, "%s", md->md_name);
2844	sc = malloc(sizeof(*sc), M_MIRROR, M_WAITOK | M_ZERO);
2845	gp->start = g_mirror_start;
2846	gp->orphan = g_mirror_orphan;
2847	gp->access = g_mirror_access;
2848	gp->dumpconf = g_mirror_dumpconf;
2849
2850	sc->sc_id = md->md_mid;
2851	sc->sc_slice = md->md_slice;
2852	sc->sc_balance = md->md_balance;
2853	sc->sc_mediasize = md->md_mediasize;
2854	sc->sc_sectorsize = md->md_sectorsize;
2855	sc->sc_ndisks = md->md_all;
2856	sc->sc_flags = md->md_mflags;
2857	sc->sc_bump_id = 0;
2858	sc->sc_idle = 1;
2859	sc->sc_last_write = time_uptime;
2860	sc->sc_writes = 0;
2861	sx_init(&sc->sc_lock, "gmirror:lock");
2862	bioq_init(&sc->sc_queue);
2863	mtx_init(&sc->sc_queue_mtx, "gmirror:queue", NULL, MTX_DEF);
2864	bioq_init(&sc->sc_regular_delayed);
2865	bioq_init(&sc->sc_inflight);
2866	bioq_init(&sc->sc_sync_delayed);
2867	LIST_INIT(&sc->sc_disks);
2868	TAILQ_INIT(&sc->sc_events);
2869	mtx_init(&sc->sc_events_mtx, "gmirror:events", NULL, MTX_DEF);
2870	callout_init(&sc->sc_callout, CALLOUT_MPSAFE);
2871	sc->sc_state = G_MIRROR_DEVICE_STATE_STARTING;
2872	gp->softc = sc;
2873	sc->sc_geom = gp;
2874	sc->sc_provider = NULL;
2875	/*
2876	 * Synchronization geom.
2877	 */
2878	gp = g_new_geomf(mp, "%s.sync", md->md_name);
2879	gp->softc = sc;
2880	gp->orphan = g_mirror_orphan;
2881	sc->sc_sync.ds_geom = gp;
2882	sc->sc_sync.ds_ndisks = 0;
2883	error = kproc_create(g_mirror_worker, sc, &sc->sc_worker, 0, 0,
2884	    "g_mirror %s", md->md_name);
2885	if (error != 0) {
2886		G_MIRROR_DEBUG(1, "Cannot create kernel thread for %s.",
2887		    sc->sc_name);
2888		g_destroy_geom(sc->sc_sync.ds_geom);
2889		mtx_destroy(&sc->sc_events_mtx);
2890		mtx_destroy(&sc->sc_queue_mtx);
2891		sx_destroy(&sc->sc_lock);
2892		g_destroy_geom(sc->sc_geom);
2893		free(sc, M_MIRROR);
2894		return (NULL);
2895	}
2896
2897	G_MIRROR_DEBUG(1, "Device %s created (%u components, id=%u).",
2898	    sc->sc_name, sc->sc_ndisks, sc->sc_id);
2899
2900	sc->sc_rootmount = root_mount_hold("GMIRROR");
2901	G_MIRROR_DEBUG(1, "root_mount_hold %p", sc->sc_rootmount);
2902	/*
2903	 * Run timeout.
2904	 */
2905	timeout = g_mirror_timeout * hz;
2906	callout_reset(&sc->sc_callout, timeout, g_mirror_go, sc);
2907	return (sc->sc_geom);
2908}
2909
2910int
2911g_mirror_destroy(struct g_mirror_softc *sc, int how)
2912{
2913	struct g_mirror_disk *disk;
2914	struct g_provider *pp;
2915
2916	g_topology_assert_not();
2917	if (sc == NULL)
2918		return (ENXIO);
2919	sx_assert(&sc->sc_lock, SX_XLOCKED);
2920
2921	pp = sc->sc_provider;
2922	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
2923		switch (how) {
2924		case G_MIRROR_DESTROY_SOFT:
2925			G_MIRROR_DEBUG(1,
2926			    "Device %s is still open (r%dw%de%d).", pp->name,
2927			    pp->acr, pp->acw, pp->ace);
2928			return (EBUSY);
2929		case G_MIRROR_DESTROY_DELAYED:
2930			G_MIRROR_DEBUG(1,
2931			    "Device %s will be destroyed on last close.",
2932			    pp->name);
2933			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2934				if (disk->d_state ==
2935				    G_MIRROR_DISK_STATE_SYNCHRONIZING) {
2936					g_mirror_sync_stop(disk, 1);
2937				}
2938			}
2939			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROYING;
2940			return (EBUSY);
2941		case G_MIRROR_DESTROY_HARD:
2942			G_MIRROR_DEBUG(1, "Device %s is still open, so it "
2943			    "can't be definitely removed.", pp->name);
2944		}
2945	}
2946
2947	g_topology_lock();
2948	if (sc->sc_geom->softc == NULL) {
2949		g_topology_unlock();
2950		return (0);
2951	}
2952	sc->sc_geom->softc = NULL;
2953	sc->sc_sync.ds_geom->softc = NULL;
2954	g_topology_unlock();
2955
2956	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2957	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_WAIT;
2958	G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
2959	sx_xunlock(&sc->sc_lock);
2960	mtx_lock(&sc->sc_queue_mtx);
2961	wakeup(sc);
2962	mtx_unlock(&sc->sc_queue_mtx);
2963	G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, &sc->sc_worker);
2964	while (sc->sc_worker != NULL)
2965		tsleep(&sc->sc_worker, PRIBIO, "m:destroy", hz / 5);
2966	G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, &sc->sc_worker);
2967	sx_xlock(&sc->sc_lock);
2968	g_mirror_destroy_device(sc);
2969	free(sc, M_MIRROR);
2970	return (0);
2971}
2972
2973static void
2974g_mirror_taste_orphan(struct g_consumer *cp)
2975{
2976
2977	KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
2978	    cp->provider->name));
2979}
2980
2981static struct g_geom *
2982g_mirror_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
2983{
2984	struct g_mirror_metadata md;
2985	struct g_mirror_softc *sc;
2986	struct g_consumer *cp;
2987	struct g_geom *gp;
2988	int error;
2989
2990	g_topology_assert();
2991	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
2992	G_MIRROR_DEBUG(2, "Tasting %s.", pp->name);
2993
2994	gp = g_new_geomf(mp, "mirror:taste");
2995	/*
2996	 * This orphan function should be never called.
2997	 */
2998	gp->orphan = g_mirror_taste_orphan;
2999	cp = g_new_consumer(gp);
3000	g_attach(cp, pp);
3001	error = g_mirror_read_metadata(cp, &md);
3002	g_detach(cp);
3003	g_destroy_consumer(cp);
3004	g_destroy_geom(gp);
3005	if (error != 0)
3006		return (NULL);
3007	gp = NULL;
3008
3009	if (md.md_provider[0] != '\0' && strcmp(md.md_provider, pp->name) != 0)
3010		return (NULL);
3011	if (md.md_provsize != 0 && md.md_provsize != pp->mediasize)
3012		return (NULL);
3013	if ((md.md_dflags & G_MIRROR_DISK_FLAG_INACTIVE) != 0) {
3014		G_MIRROR_DEBUG(0,
3015		    "Device %s: provider %s marked as inactive, skipping.",
3016		    md.md_name, pp->name);
3017		return (NULL);
3018	}
3019	if (g_mirror_debug >= 2)
3020		mirror_metadata_dump(&md);
3021
3022	/*
3023	 * Let's check if device already exists.
3024	 */
3025	sc = NULL;
3026	LIST_FOREACH(gp, &mp->geom, geom) {
3027		sc = gp->softc;
3028		if (sc == NULL)
3029			continue;
3030		if (sc->sc_sync.ds_geom == gp)
3031			continue;
3032		if (strcmp(md.md_name, sc->sc_name) != 0)
3033			continue;
3034		if (md.md_mid != sc->sc_id) {
3035			G_MIRROR_DEBUG(0, "Device %s already configured.",
3036			    sc->sc_name);
3037			return (NULL);
3038		}
3039		break;
3040	}
3041	if (gp == NULL) {
3042		gp = g_mirror_create(mp, &md);
3043		if (gp == NULL) {
3044			G_MIRROR_DEBUG(0, "Cannot create device %s.",
3045			    md.md_name);
3046			return (NULL);
3047		}
3048		sc = gp->softc;
3049	}
3050	G_MIRROR_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
3051	g_topology_unlock();
3052	sx_xlock(&sc->sc_lock);
3053	error = g_mirror_add_disk(sc, pp, &md);
3054	if (error != 0) {
3055		G_MIRROR_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
3056		    pp->name, gp->name, error);
3057		if (LIST_EMPTY(&sc->sc_disks)) {
3058			g_cancel_event(sc);
3059			g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
3060			g_topology_lock();
3061			return (NULL);
3062		}
3063		gp = NULL;
3064	}
3065	sx_xunlock(&sc->sc_lock);
3066	g_topology_lock();
3067	return (gp);
3068}
3069
3070static int
3071g_mirror_destroy_geom(struct gctl_req *req __unused,
3072    struct g_class *mp __unused, struct g_geom *gp)
3073{
3074	struct g_mirror_softc *sc;
3075	int error;
3076
3077	g_topology_unlock();
3078	sc = gp->softc;
3079	sx_xlock(&sc->sc_lock);
3080	g_cancel_event(sc);
3081	error = g_mirror_destroy(gp->softc, G_MIRROR_DESTROY_SOFT);
3082	if (error != 0)
3083		sx_xunlock(&sc->sc_lock);
3084	g_topology_lock();
3085	return (error);
3086}
3087
3088static void
3089g_mirror_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
3090    struct g_consumer *cp, struct g_provider *pp)
3091{
3092	struct g_mirror_softc *sc;
3093
3094	g_topology_assert();
3095
3096	sc = gp->softc;
3097	if (sc == NULL)
3098		return;
3099	/* Skip synchronization geom. */
3100	if (gp == sc->sc_sync.ds_geom)
3101		return;
3102	if (pp != NULL) {
3103		/* Nothing here. */
3104	} else if (cp != NULL) {
3105		struct g_mirror_disk *disk;
3106
3107		disk = cp->private;
3108		if (disk == NULL)
3109			return;
3110		g_topology_unlock();
3111		sx_xlock(&sc->sc_lock);
3112		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)disk->d_id);
3113		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
3114			sbuf_printf(sb, "%s<Synchronized>", indent);
3115			if (disk->d_sync.ds_offset == 0)
3116				sbuf_printf(sb, "0%%");
3117			else {
3118				sbuf_printf(sb, "%u%%",
3119				    (u_int)((disk->d_sync.ds_offset * 100) /
3120				    sc->sc_provider->mediasize));
3121			}
3122			sbuf_printf(sb, "</Synchronized>\n");
3123		}
3124		sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent,
3125		    disk->d_sync.ds_syncid);
3126		sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent,
3127		    disk->d_genid);
3128		sbuf_printf(sb, "%s<Flags>", indent);
3129		if (disk->d_flags == 0)
3130			sbuf_printf(sb, "NONE");
3131		else {
3132			int first = 1;
3133
3134#define	ADD_FLAG(flag, name)	do {					\
3135	if ((disk->d_flags & (flag)) != 0) {				\
3136		if (!first)						\
3137			sbuf_printf(sb, ", ");				\
3138		else							\
3139			first = 0;					\
3140		sbuf_printf(sb, name);					\
3141	}								\
3142} while (0)
3143			ADD_FLAG(G_MIRROR_DISK_FLAG_DIRTY, "DIRTY");
3144			ADD_FLAG(G_MIRROR_DISK_FLAG_HARDCODED, "HARDCODED");
3145			ADD_FLAG(G_MIRROR_DISK_FLAG_INACTIVE, "INACTIVE");
3146			ADD_FLAG(G_MIRROR_DISK_FLAG_SYNCHRONIZING,
3147			    "SYNCHRONIZING");
3148			ADD_FLAG(G_MIRROR_DISK_FLAG_FORCE_SYNC, "FORCE_SYNC");
3149			ADD_FLAG(G_MIRROR_DISK_FLAG_BROKEN, "BROKEN");
3150#undef	ADD_FLAG
3151		}
3152		sbuf_printf(sb, "</Flags>\n");
3153		sbuf_printf(sb, "%s<Priority>%u</Priority>\n", indent,
3154		    disk->d_priority);
3155		sbuf_printf(sb, "%s<State>%s</State>\n", indent,
3156		    g_mirror_disk_state2str(disk->d_state));
3157		sx_xunlock(&sc->sc_lock);
3158		g_topology_lock();
3159	} else {
3160		g_topology_unlock();
3161		sx_xlock(&sc->sc_lock);
3162		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
3163		sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent, sc->sc_syncid);
3164		sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent, sc->sc_genid);
3165		sbuf_printf(sb, "%s<Flags>", indent);
3166		if (sc->sc_flags == 0)
3167			sbuf_printf(sb, "NONE");
3168		else {
3169			int first = 1;
3170
3171#define	ADD_FLAG(flag, name)	do {					\
3172	if ((sc->sc_flags & (flag)) != 0) {				\
3173		if (!first)						\
3174			sbuf_printf(sb, ", ");				\
3175		else							\
3176			first = 0;					\
3177		sbuf_printf(sb, name);					\
3178	}								\
3179} while (0)
3180			ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOFAILSYNC, "NOFAILSYNC");
3181			ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOAUTOSYNC, "NOAUTOSYNC");
3182#undef	ADD_FLAG
3183		}
3184		sbuf_printf(sb, "</Flags>\n");
3185		sbuf_printf(sb, "%s<Slice>%u</Slice>\n", indent,
3186		    (u_int)sc->sc_slice);
3187		sbuf_printf(sb, "%s<Balance>%s</Balance>\n", indent,
3188		    balance_name(sc->sc_balance));
3189		sbuf_printf(sb, "%s<Components>%u</Components>\n", indent,
3190		    sc->sc_ndisks);
3191		sbuf_printf(sb, "%s<State>", indent);
3192		if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
3193			sbuf_printf(sb, "%s", "STARTING");
3194		else if (sc->sc_ndisks ==
3195		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE))
3196			sbuf_printf(sb, "%s", "COMPLETE");
3197		else
3198			sbuf_printf(sb, "%s", "DEGRADED");
3199		sbuf_printf(sb, "</State>\n");
3200		sx_xunlock(&sc->sc_lock);
3201		g_topology_lock();
3202	}
3203}
3204
3205static void
3206g_mirror_shutdown_pre_sync(void *arg, int howto)
3207{
3208	struct g_class *mp;
3209	struct g_geom *gp, *gp2;
3210	struct g_mirror_softc *sc;
3211	int error;
3212
3213	mp = arg;
3214	DROP_GIANT();
3215	g_topology_lock();
3216	LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
3217		if ((sc = gp->softc) == NULL)
3218			continue;
3219		/* Skip synchronization geom. */
3220		if (gp == sc->sc_sync.ds_geom)
3221			continue;
3222		g_topology_unlock();
3223		sx_xlock(&sc->sc_lock);
3224		g_cancel_event(sc);
3225		error = g_mirror_destroy(sc, G_MIRROR_DESTROY_DELAYED);
3226		if (error != 0)
3227			sx_xunlock(&sc->sc_lock);
3228		g_topology_lock();
3229	}
3230	g_topology_unlock();
3231	PICKUP_GIANT();
3232}
3233
3234static void
3235g_mirror_init(struct g_class *mp)
3236{
3237
3238	g_mirror_pre_sync = EVENTHANDLER_REGISTER(shutdown_pre_sync,
3239	    g_mirror_shutdown_pre_sync, mp, SHUTDOWN_PRI_FIRST);
3240	if (g_mirror_pre_sync == NULL)
3241		G_MIRROR_DEBUG(0, "Warning! Cannot register shutdown event.");
3242}
3243
3244static void
3245g_mirror_fini(struct g_class *mp)
3246{
3247
3248	if (g_mirror_pre_sync != NULL)
3249		EVENTHANDLER_DEREGISTER(shutdown_pre_sync, g_mirror_pre_sync);
3250}
3251
3252DECLARE_GEOM_CLASS(g_mirror_class, g_mirror);
3253