g_mirror.c revision 252010
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 252010 2013-06-19 21:52:32Z scottl $");
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/sbuf.h>
39#include <sys/sysctl.h>
40#include <sys/malloc.h>
41#include <sys/eventhandler.h>
42#include <vm/uma.h>
43#include <geom/geom.h>
44#include <sys/proc.h>
45#include <sys/kthread.h>
46#include <sys/sched.h>
47#include <geom/mirror/g_mirror.h>
48
49FEATURE(geom_mirror, "GEOM mirroring support");
50
51static MALLOC_DEFINE(M_MIRROR, "mirror_data", "GEOM_MIRROR Data");
52
53SYSCTL_DECL(_kern_geom);
54static SYSCTL_NODE(_kern_geom, OID_AUTO, mirror, CTLFLAG_RW, 0,
55    "GEOM_MIRROR stuff");
56u_int g_mirror_debug = 0;
57TUNABLE_INT("kern.geom.mirror.debug", &g_mirror_debug);
58SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, debug, CTLFLAG_RW, &g_mirror_debug, 0,
59    "Debug level");
60static u_int g_mirror_timeout = 4;
61TUNABLE_INT("kern.geom.mirror.timeout", &g_mirror_timeout);
62SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, timeout, CTLFLAG_RW, &g_mirror_timeout,
63    0, "Time to wait on all mirror components");
64static u_int g_mirror_idletime = 5;
65TUNABLE_INT("kern.geom.mirror.idletime", &g_mirror_idletime);
66SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, idletime, CTLFLAG_RW,
67    &g_mirror_idletime, 0, "Mark components as clean when idling");
68static u_int g_mirror_disconnect_on_failure = 1;
69TUNABLE_INT("kern.geom.mirror.disconnect_on_failure",
70    &g_mirror_disconnect_on_failure);
71SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, disconnect_on_failure, CTLFLAG_RW,
72    &g_mirror_disconnect_on_failure, 0, "Disconnect component on I/O failure.");
73static u_int g_mirror_syncreqs = 2;
74TUNABLE_INT("kern.geom.mirror.sync_requests", &g_mirror_syncreqs);
75SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, sync_requests, CTLFLAG_RDTUN,
76    &g_mirror_syncreqs, 0, "Parallel synchronization I/O requests.");
77
78#define	MSLEEP(ident, mtx, priority, wmesg, timeout)	do {		\
79	G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, (ident));	\
80	msleep((ident), (mtx), (priority), (wmesg), (timeout));		\
81	G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, (ident));	\
82} while (0)
83
84static eventhandler_tag g_mirror_post_sync = NULL;
85static int g_mirror_shutdown = 0;
86
87static int g_mirror_destroy_geom(struct gctl_req *req, struct g_class *mp,
88    struct g_geom *gp);
89static g_taste_t g_mirror_taste;
90static void g_mirror_init(struct g_class *mp);
91static void g_mirror_fini(struct g_class *mp);
92
93struct g_class g_mirror_class = {
94	.name = G_MIRROR_CLASS_NAME,
95	.version = G_VERSION,
96	.ctlreq = g_mirror_config,
97	.taste = g_mirror_taste,
98	.destroy_geom = g_mirror_destroy_geom,
99	.init = g_mirror_init,
100	.fini = g_mirror_fini
101};
102
103
104static void g_mirror_destroy_provider(struct g_mirror_softc *sc);
105static int g_mirror_update_disk(struct g_mirror_disk *disk, u_int state);
106static void g_mirror_update_device(struct g_mirror_softc *sc, boolean_t force);
107static void g_mirror_dumpconf(struct sbuf *sb, const char *indent,
108    struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp);
109static void g_mirror_sync_stop(struct g_mirror_disk *disk, int type);
110static void g_mirror_register_request(struct bio *bp);
111static void g_mirror_sync_release(struct g_mirror_softc *sc);
112
113
114static const char *
115g_mirror_disk_state2str(int state)
116{
117
118	switch (state) {
119	case G_MIRROR_DISK_STATE_NONE:
120		return ("NONE");
121	case G_MIRROR_DISK_STATE_NEW:
122		return ("NEW");
123	case G_MIRROR_DISK_STATE_ACTIVE:
124		return ("ACTIVE");
125	case G_MIRROR_DISK_STATE_STALE:
126		return ("STALE");
127	case G_MIRROR_DISK_STATE_SYNCHRONIZING:
128		return ("SYNCHRONIZING");
129	case G_MIRROR_DISK_STATE_DISCONNECTED:
130		return ("DISCONNECTED");
131	case G_MIRROR_DISK_STATE_DESTROY:
132		return ("DESTROY");
133	default:
134		return ("INVALID");
135	}
136}
137
138static const char *
139g_mirror_device_state2str(int state)
140{
141
142	switch (state) {
143	case G_MIRROR_DEVICE_STATE_STARTING:
144		return ("STARTING");
145	case G_MIRROR_DEVICE_STATE_RUNNING:
146		return ("RUNNING");
147	default:
148		return ("INVALID");
149	}
150}
151
152static const char *
153g_mirror_get_diskname(struct g_mirror_disk *disk)
154{
155
156	if (disk->d_consumer == NULL || disk->d_consumer->provider == NULL)
157		return ("[unknown]");
158	return (disk->d_name);
159}
160
161/*
162 * --- Events handling functions ---
163 * Events in geom_mirror are used to maintain disks and device status
164 * from one thread to simplify locking.
165 */
166static void
167g_mirror_event_free(struct g_mirror_event *ep)
168{
169
170	free(ep, M_MIRROR);
171}
172
173int
174g_mirror_event_send(void *arg, int state, int flags)
175{
176	struct g_mirror_softc *sc;
177	struct g_mirror_disk *disk;
178	struct g_mirror_event *ep;
179	int error;
180
181	ep = malloc(sizeof(*ep), M_MIRROR, M_WAITOK);
182	G_MIRROR_DEBUG(4, "%s: Sending event %p.", __func__, ep);
183	if ((flags & G_MIRROR_EVENT_DEVICE) != 0) {
184		disk = NULL;
185		sc = arg;
186	} else {
187		disk = arg;
188		sc = disk->d_softc;
189	}
190	ep->e_disk = disk;
191	ep->e_state = state;
192	ep->e_flags = flags;
193	ep->e_error = 0;
194	mtx_lock(&sc->sc_events_mtx);
195	TAILQ_INSERT_TAIL(&sc->sc_events, ep, e_next);
196	mtx_unlock(&sc->sc_events_mtx);
197	G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
198	mtx_lock(&sc->sc_queue_mtx);
199	wakeup(sc);
200	mtx_unlock(&sc->sc_queue_mtx);
201	if ((flags & G_MIRROR_EVENT_DONTWAIT) != 0)
202		return (0);
203	sx_assert(&sc->sc_lock, SX_XLOCKED);
204	G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, ep);
205	sx_xunlock(&sc->sc_lock);
206	while ((ep->e_flags & G_MIRROR_EVENT_DONE) == 0) {
207		mtx_lock(&sc->sc_events_mtx);
208		MSLEEP(ep, &sc->sc_events_mtx, PRIBIO | PDROP, "m:event",
209		    hz * 5);
210	}
211	error = ep->e_error;
212	g_mirror_event_free(ep);
213	sx_xlock(&sc->sc_lock);
214	return (error);
215}
216
217static struct g_mirror_event *
218g_mirror_event_get(struct g_mirror_softc *sc)
219{
220	struct g_mirror_event *ep;
221
222	mtx_lock(&sc->sc_events_mtx);
223	ep = TAILQ_FIRST(&sc->sc_events);
224	mtx_unlock(&sc->sc_events_mtx);
225	return (ep);
226}
227
228static void
229g_mirror_event_remove(struct g_mirror_softc *sc, struct g_mirror_event *ep)
230{
231
232	mtx_lock(&sc->sc_events_mtx);
233	TAILQ_REMOVE(&sc->sc_events, ep, e_next);
234	mtx_unlock(&sc->sc_events_mtx);
235}
236
237static void
238g_mirror_event_cancel(struct g_mirror_disk *disk)
239{
240	struct g_mirror_softc *sc;
241	struct g_mirror_event *ep, *tmpep;
242
243	sc = disk->d_softc;
244	sx_assert(&sc->sc_lock, SX_XLOCKED);
245
246	mtx_lock(&sc->sc_events_mtx);
247	TAILQ_FOREACH_SAFE(ep, &sc->sc_events, e_next, tmpep) {
248		if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0)
249			continue;
250		if (ep->e_disk != disk)
251			continue;
252		TAILQ_REMOVE(&sc->sc_events, ep, e_next);
253		if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
254			g_mirror_event_free(ep);
255		else {
256			ep->e_error = ECANCELED;
257			wakeup(ep);
258		}
259	}
260	mtx_unlock(&sc->sc_events_mtx);
261}
262
263/*
264 * Return the number of disks in given state.
265 * If state is equal to -1, count all connected disks.
266 */
267u_int
268g_mirror_ndisks(struct g_mirror_softc *sc, int state)
269{
270	struct g_mirror_disk *disk;
271	u_int n = 0;
272
273	sx_assert(&sc->sc_lock, SX_LOCKED);
274
275	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
276		if (state == -1 || disk->d_state == state)
277			n++;
278	}
279	return (n);
280}
281
282/*
283 * Find a disk in mirror by its disk ID.
284 */
285static struct g_mirror_disk *
286g_mirror_id2disk(struct g_mirror_softc *sc, uint32_t id)
287{
288	struct g_mirror_disk *disk;
289
290	sx_assert(&sc->sc_lock, SX_XLOCKED);
291
292	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
293		if (disk->d_id == id)
294			return (disk);
295	}
296	return (NULL);
297}
298
299static u_int
300g_mirror_nrequests(struct g_mirror_softc *sc, struct g_consumer *cp)
301{
302	struct bio *bp;
303	u_int nreqs = 0;
304
305	mtx_lock(&sc->sc_queue_mtx);
306	TAILQ_FOREACH(bp, &sc->sc_queue.queue, bio_queue) {
307		if (bp->bio_from == cp)
308			nreqs++;
309	}
310	mtx_unlock(&sc->sc_queue_mtx);
311	return (nreqs);
312}
313
314static int
315g_mirror_is_busy(struct g_mirror_softc *sc, struct g_consumer *cp)
316{
317
318	if (cp->index > 0) {
319		G_MIRROR_DEBUG(2,
320		    "I/O requests for %s exist, can't destroy it now.",
321		    cp->provider->name);
322		return (1);
323	}
324	if (g_mirror_nrequests(sc, cp) > 0) {
325		G_MIRROR_DEBUG(2,
326		    "I/O requests for %s in queue, can't destroy it now.",
327		    cp->provider->name);
328		return (1);
329	}
330	return (0);
331}
332
333static void
334g_mirror_destroy_consumer(void *arg, int flags __unused)
335{
336	struct g_consumer *cp;
337
338	g_topology_assert();
339
340	cp = arg;
341	G_MIRROR_DEBUG(1, "Consumer %s destroyed.", cp->provider->name);
342	g_detach(cp);
343	g_destroy_consumer(cp);
344}
345
346static void
347g_mirror_kill_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
348{
349	struct g_provider *pp;
350	int retaste_wait;
351
352	g_topology_assert();
353
354	cp->private = NULL;
355	if (g_mirror_is_busy(sc, cp))
356		return;
357	pp = cp->provider;
358	retaste_wait = 0;
359	if (cp->acw == 1) {
360		if ((pp->geom->flags & G_GEOM_WITHER) == 0)
361			retaste_wait = 1;
362	}
363	G_MIRROR_DEBUG(2, "Access %s r%dw%de%d = %d", pp->name, -cp->acr,
364	    -cp->acw, -cp->ace, 0);
365	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
366		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
367	if (retaste_wait) {
368		/*
369		 * After retaste event was send (inside g_access()), we can send
370		 * event to detach and destroy consumer.
371		 * A class, which has consumer to the given provider connected
372		 * will not receive retaste event for the provider.
373		 * This is the way how I ignore retaste events when I close
374		 * consumers opened for write: I detach and destroy consumer
375		 * after retaste event is sent.
376		 */
377		g_post_event(g_mirror_destroy_consumer, cp, M_WAITOK, NULL);
378		return;
379	}
380	G_MIRROR_DEBUG(1, "Consumer %s destroyed.", pp->name);
381	g_detach(cp);
382	g_destroy_consumer(cp);
383}
384
385static int
386g_mirror_connect_disk(struct g_mirror_disk *disk, struct g_provider *pp)
387{
388	struct g_consumer *cp;
389	int error;
390
391	g_topology_assert_not();
392	KASSERT(disk->d_consumer == NULL,
393	    ("Disk already connected (device %s).", disk->d_softc->sc_name));
394
395	g_topology_lock();
396	cp = g_new_consumer(disk->d_softc->sc_geom);
397	error = g_attach(cp, pp);
398	if (error != 0) {
399		g_destroy_consumer(cp);
400		g_topology_unlock();
401		return (error);
402	}
403	error = g_access(cp, 1, 1, 1);
404	if (error != 0) {
405		g_detach(cp);
406		g_destroy_consumer(cp);
407		g_topology_unlock();
408		G_MIRROR_DEBUG(0, "Cannot open consumer %s (error=%d).",
409		    pp->name, error);
410		return (error);
411	}
412	g_topology_unlock();
413	disk->d_consumer = cp;
414	disk->d_consumer->private = disk;
415	disk->d_consumer->index = 0;
416
417	G_MIRROR_DEBUG(2, "Disk %s connected.", g_mirror_get_diskname(disk));
418	return (0);
419}
420
421static void
422g_mirror_disconnect_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
423{
424
425	g_topology_assert();
426
427	if (cp == NULL)
428		return;
429	if (cp->provider != NULL)
430		g_mirror_kill_consumer(sc, cp);
431	else
432		g_destroy_consumer(cp);
433}
434
435/*
436 * Initialize disk. This means allocate memory, create consumer, attach it
437 * to the provider and open access (r1w1e1) to it.
438 */
439static struct g_mirror_disk *
440g_mirror_init_disk(struct g_mirror_softc *sc, struct g_provider *pp,
441    struct g_mirror_metadata *md, int *errorp)
442{
443	struct g_mirror_disk *disk;
444	int i, error;
445
446	disk = malloc(sizeof(*disk), M_MIRROR, M_NOWAIT | M_ZERO);
447	if (disk == NULL) {
448		error = ENOMEM;
449		goto fail;
450	}
451	disk->d_softc = sc;
452	error = g_mirror_connect_disk(disk, pp);
453	if (error != 0)
454		goto fail;
455	disk->d_id = md->md_did;
456	disk->d_state = G_MIRROR_DISK_STATE_NONE;
457	disk->d_priority = md->md_priority;
458	disk->d_flags = md->md_dflags;
459	error = g_getattr("GEOM::candelete", disk->d_consumer, &i);
460	if (error == 0 && i != 0)
461		disk->d_flags |= G_MIRROR_DISK_FLAG_CANDELETE;
462	if (md->md_provider[0] != '\0')
463		disk->d_flags |= G_MIRROR_DISK_FLAG_HARDCODED;
464	disk->d_sync.ds_consumer = NULL;
465	disk->d_sync.ds_offset = md->md_sync_offset;
466	disk->d_sync.ds_offset_done = md->md_sync_offset;
467	disk->d_genid = md->md_genid;
468	disk->d_sync.ds_syncid = md->md_syncid;
469	if (errorp != NULL)
470		*errorp = 0;
471	return (disk);
472fail:
473	if (errorp != NULL)
474		*errorp = error;
475	if (disk != NULL)
476		free(disk, M_MIRROR);
477	return (NULL);
478}
479
480static void
481g_mirror_destroy_disk(struct g_mirror_disk *disk)
482{
483	struct g_mirror_softc *sc;
484
485	g_topology_assert_not();
486	sc = disk->d_softc;
487	sx_assert(&sc->sc_lock, SX_XLOCKED);
488
489	LIST_REMOVE(disk, d_next);
490	g_mirror_event_cancel(disk);
491	if (sc->sc_hint == disk)
492		sc->sc_hint = NULL;
493	switch (disk->d_state) {
494	case G_MIRROR_DISK_STATE_SYNCHRONIZING:
495		g_mirror_sync_stop(disk, 1);
496		/* FALLTHROUGH */
497	case G_MIRROR_DISK_STATE_NEW:
498	case G_MIRROR_DISK_STATE_STALE:
499	case G_MIRROR_DISK_STATE_ACTIVE:
500		g_topology_lock();
501		g_mirror_disconnect_consumer(sc, disk->d_consumer);
502		g_topology_unlock();
503		free(disk, M_MIRROR);
504		break;
505	default:
506		KASSERT(0 == 1, ("Wrong disk state (%s, %s).",
507		    g_mirror_get_diskname(disk),
508		    g_mirror_disk_state2str(disk->d_state)));
509	}
510}
511
512static void
513g_mirror_destroy_device(struct g_mirror_softc *sc)
514{
515	struct g_mirror_disk *disk;
516	struct g_mirror_event *ep;
517	struct g_geom *gp;
518	struct g_consumer *cp, *tmpcp;
519
520	g_topology_assert_not();
521	sx_assert(&sc->sc_lock, SX_XLOCKED);
522
523	gp = sc->sc_geom;
524	if (sc->sc_provider != NULL)
525		g_mirror_destroy_provider(sc);
526	for (disk = LIST_FIRST(&sc->sc_disks); disk != NULL;
527	    disk = LIST_FIRST(&sc->sc_disks)) {
528		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
529		g_mirror_update_metadata(disk);
530		g_mirror_destroy_disk(disk);
531	}
532	while ((ep = g_mirror_event_get(sc)) != NULL) {
533		g_mirror_event_remove(sc, ep);
534		if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
535			g_mirror_event_free(ep);
536		else {
537			ep->e_error = ECANCELED;
538			ep->e_flags |= G_MIRROR_EVENT_DONE;
539			G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, ep);
540			mtx_lock(&sc->sc_events_mtx);
541			wakeup(ep);
542			mtx_unlock(&sc->sc_events_mtx);
543		}
544	}
545	callout_drain(&sc->sc_callout);
546
547	g_topology_lock();
548	LIST_FOREACH_SAFE(cp, &sc->sc_sync.ds_geom->consumer, consumer, tmpcp) {
549		g_mirror_disconnect_consumer(sc, cp);
550	}
551	g_wither_geom(sc->sc_sync.ds_geom, ENXIO);
552	G_MIRROR_DEBUG(0, "Device %s destroyed.", gp->name);
553	g_wither_geom(gp, ENXIO);
554	g_topology_unlock();
555	mtx_destroy(&sc->sc_queue_mtx);
556	mtx_destroy(&sc->sc_events_mtx);
557	sx_xunlock(&sc->sc_lock);
558	sx_destroy(&sc->sc_lock);
559}
560
561static void
562g_mirror_orphan(struct g_consumer *cp)
563{
564	struct g_mirror_disk *disk;
565
566	g_topology_assert();
567
568	disk = cp->private;
569	if (disk == NULL)
570		return;
571	disk->d_softc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
572	g_mirror_event_send(disk, G_MIRROR_DISK_STATE_DISCONNECTED,
573	    G_MIRROR_EVENT_DONTWAIT);
574}
575
576/*
577 * Function should return the next active disk on the list.
578 * It is possible that it will be the same disk as given.
579 * If there are no active disks on list, NULL is returned.
580 */
581static __inline struct g_mirror_disk *
582g_mirror_find_next(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
583{
584	struct g_mirror_disk *dp;
585
586	for (dp = LIST_NEXT(disk, d_next); dp != disk;
587	    dp = LIST_NEXT(dp, d_next)) {
588		if (dp == NULL)
589			dp = LIST_FIRST(&sc->sc_disks);
590		if (dp->d_state == G_MIRROR_DISK_STATE_ACTIVE)
591			break;
592	}
593	if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
594		return (NULL);
595	return (dp);
596}
597
598static struct g_mirror_disk *
599g_mirror_get_disk(struct g_mirror_softc *sc)
600{
601	struct g_mirror_disk *disk;
602
603	if (sc->sc_hint == NULL) {
604		sc->sc_hint = LIST_FIRST(&sc->sc_disks);
605		if (sc->sc_hint == NULL)
606			return (NULL);
607	}
608	disk = sc->sc_hint;
609	if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE) {
610		disk = g_mirror_find_next(sc, disk);
611		if (disk == NULL)
612			return (NULL);
613	}
614	sc->sc_hint = g_mirror_find_next(sc, disk);
615	return (disk);
616}
617
618static int
619g_mirror_write_metadata(struct g_mirror_disk *disk,
620    struct g_mirror_metadata *md)
621{
622	struct g_mirror_softc *sc;
623	struct g_consumer *cp;
624	off_t offset, length;
625	u_char *sector;
626	int error = 0;
627
628	g_topology_assert_not();
629	sc = disk->d_softc;
630	sx_assert(&sc->sc_lock, SX_LOCKED);
631
632	cp = disk->d_consumer;
633	KASSERT(cp != NULL, ("NULL consumer (%s).", sc->sc_name));
634	KASSERT(cp->provider != NULL, ("NULL provider (%s).", sc->sc_name));
635	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
636	    ("Consumer %s closed? (r%dw%de%d).", cp->provider->name, cp->acr,
637	    cp->acw, cp->ace));
638	length = cp->provider->sectorsize;
639	offset = cp->provider->mediasize - length;
640	sector = malloc((size_t)length, M_MIRROR, M_WAITOK | M_ZERO);
641	if (md != NULL)
642		mirror_metadata_encode(md, sector);
643	error = g_write_data(cp, offset, sector, length);
644	free(sector, M_MIRROR);
645	if (error != 0) {
646		if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
647			disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
648			G_MIRROR_DEBUG(0, "Cannot write metadata on %s "
649			    "(device=%s, error=%d).",
650			    g_mirror_get_diskname(disk), sc->sc_name, error);
651		} else {
652			G_MIRROR_DEBUG(1, "Cannot write metadata on %s "
653			    "(device=%s, error=%d).",
654			    g_mirror_get_diskname(disk), sc->sc_name, error);
655		}
656		if (g_mirror_disconnect_on_failure &&
657		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1) {
658			sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
659			g_mirror_event_send(disk,
660			    G_MIRROR_DISK_STATE_DISCONNECTED,
661			    G_MIRROR_EVENT_DONTWAIT);
662		}
663	}
664	return (error);
665}
666
667static int
668g_mirror_clear_metadata(struct g_mirror_disk *disk)
669{
670	int error;
671
672	g_topology_assert_not();
673	sx_assert(&disk->d_softc->sc_lock, SX_LOCKED);
674
675	error = g_mirror_write_metadata(disk, NULL);
676	if (error == 0) {
677		G_MIRROR_DEBUG(2, "Metadata on %s cleared.",
678		    g_mirror_get_diskname(disk));
679	} else {
680		G_MIRROR_DEBUG(0,
681		    "Cannot clear metadata on disk %s (error=%d).",
682		    g_mirror_get_diskname(disk), error);
683	}
684	return (error);
685}
686
687void
688g_mirror_fill_metadata(struct g_mirror_softc *sc, struct g_mirror_disk *disk,
689    struct g_mirror_metadata *md)
690{
691
692	strlcpy(md->md_magic, G_MIRROR_MAGIC, sizeof(md->md_magic));
693	md->md_version = G_MIRROR_VERSION;
694	strlcpy(md->md_name, sc->sc_name, sizeof(md->md_name));
695	md->md_mid = sc->sc_id;
696	md->md_all = sc->sc_ndisks;
697	md->md_slice = sc->sc_slice;
698	md->md_balance = sc->sc_balance;
699	md->md_genid = sc->sc_genid;
700	md->md_mediasize = sc->sc_mediasize;
701	md->md_sectorsize = sc->sc_sectorsize;
702	md->md_mflags = (sc->sc_flags & G_MIRROR_DEVICE_FLAG_MASK);
703	bzero(md->md_provider, sizeof(md->md_provider));
704	if (disk == NULL) {
705		md->md_did = arc4random();
706		md->md_priority = 0;
707		md->md_syncid = 0;
708		md->md_dflags = 0;
709		md->md_sync_offset = 0;
710		md->md_provsize = 0;
711	} else {
712		md->md_did = disk->d_id;
713		md->md_priority = disk->d_priority;
714		md->md_syncid = disk->d_sync.ds_syncid;
715		md->md_dflags = (disk->d_flags & G_MIRROR_DISK_FLAG_MASK);
716		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
717			md->md_sync_offset = disk->d_sync.ds_offset_done;
718		else
719			md->md_sync_offset = 0;
720		if ((disk->d_flags & G_MIRROR_DISK_FLAG_HARDCODED) != 0) {
721			strlcpy(md->md_provider,
722			    disk->d_consumer->provider->name,
723			    sizeof(md->md_provider));
724		}
725		md->md_provsize = disk->d_consumer->provider->mediasize;
726	}
727}
728
729void
730g_mirror_update_metadata(struct g_mirror_disk *disk)
731{
732	struct g_mirror_softc *sc;
733	struct g_mirror_metadata md;
734	int error;
735
736	g_topology_assert_not();
737	sc = disk->d_softc;
738	sx_assert(&sc->sc_lock, SX_LOCKED);
739
740	g_mirror_fill_metadata(sc, disk, &md);
741	error = g_mirror_write_metadata(disk, &md);
742	if (error == 0) {
743		G_MIRROR_DEBUG(2, "Metadata on %s updated.",
744		    g_mirror_get_diskname(disk));
745	} else {
746		G_MIRROR_DEBUG(0,
747		    "Cannot update metadata on disk %s (error=%d).",
748		    g_mirror_get_diskname(disk), error);
749	}
750}
751
752static void
753g_mirror_bump_syncid(struct g_mirror_softc *sc)
754{
755	struct g_mirror_disk *disk;
756
757	g_topology_assert_not();
758	sx_assert(&sc->sc_lock, SX_XLOCKED);
759	KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
760	    ("%s called with no active disks (device=%s).", __func__,
761	    sc->sc_name));
762
763	sc->sc_syncid++;
764	G_MIRROR_DEBUG(1, "Device %s: syncid bumped to %u.", sc->sc_name,
765	    sc->sc_syncid);
766	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
767		if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
768		    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
769			disk->d_sync.ds_syncid = sc->sc_syncid;
770			g_mirror_update_metadata(disk);
771		}
772	}
773}
774
775static void
776g_mirror_bump_genid(struct g_mirror_softc *sc)
777{
778	struct g_mirror_disk *disk;
779
780	g_topology_assert_not();
781	sx_assert(&sc->sc_lock, SX_XLOCKED);
782	KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
783	    ("%s called with no active disks (device=%s).", __func__,
784	    sc->sc_name));
785
786	sc->sc_genid++;
787	G_MIRROR_DEBUG(1, "Device %s: genid bumped to %u.", sc->sc_name,
788	    sc->sc_genid);
789	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
790		if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
791		    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
792			disk->d_genid = sc->sc_genid;
793			g_mirror_update_metadata(disk);
794		}
795	}
796}
797
798static int
799g_mirror_idle(struct g_mirror_softc *sc, int acw)
800{
801	struct g_mirror_disk *disk;
802	int timeout;
803
804	g_topology_assert_not();
805	sx_assert(&sc->sc_lock, SX_XLOCKED);
806
807	if (sc->sc_provider == NULL)
808		return (0);
809	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
810		return (0);
811	if (sc->sc_idle)
812		return (0);
813	if (sc->sc_writes > 0)
814		return (0);
815	if (acw > 0 || (acw == -1 && sc->sc_provider->acw > 0)) {
816		timeout = g_mirror_idletime - (time_uptime - sc->sc_last_write);
817		if (!g_mirror_shutdown && timeout > 0)
818			return (timeout);
819	}
820	sc->sc_idle = 1;
821	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
822		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
823			continue;
824		G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as clean.",
825		    g_mirror_get_diskname(disk), sc->sc_name);
826		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
827		g_mirror_update_metadata(disk);
828	}
829	return (0);
830}
831
832static void
833g_mirror_unidle(struct g_mirror_softc *sc)
834{
835	struct g_mirror_disk *disk;
836
837	g_topology_assert_not();
838	sx_assert(&sc->sc_lock, SX_XLOCKED);
839
840	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
841		return;
842	sc->sc_idle = 0;
843	sc->sc_last_write = time_uptime;
844	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
845		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
846			continue;
847		G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as dirty.",
848		    g_mirror_get_diskname(disk), sc->sc_name);
849		disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
850		g_mirror_update_metadata(disk);
851	}
852}
853
854static void
855g_mirror_done(struct bio *bp)
856{
857	struct g_mirror_softc *sc;
858
859	sc = bp->bio_from->geom->softc;
860	bp->bio_cflags = G_MIRROR_BIO_FLAG_REGULAR;
861	mtx_lock(&sc->sc_queue_mtx);
862	bioq_disksort(&sc->sc_queue, bp);
863	mtx_unlock(&sc->sc_queue_mtx);
864	wakeup(sc);
865}
866
867static void
868g_mirror_regular_request(struct bio *bp)
869{
870	struct g_mirror_softc *sc;
871	struct g_mirror_disk *disk;
872	struct bio *pbp;
873
874	g_topology_assert_not();
875
876	pbp = bp->bio_parent;
877	sc = pbp->bio_to->geom->softc;
878	bp->bio_from->index--;
879	if (bp->bio_cmd == BIO_WRITE)
880		sc->sc_writes--;
881	disk = bp->bio_from->private;
882	if (disk == NULL) {
883		g_topology_lock();
884		g_mirror_kill_consumer(sc, bp->bio_from);
885		g_topology_unlock();
886	}
887
888	pbp->bio_inbed++;
889	KASSERT(pbp->bio_inbed <= pbp->bio_children,
890	    ("bio_inbed (%u) is bigger than bio_children (%u).", pbp->bio_inbed,
891	    pbp->bio_children));
892	if (bp->bio_error == 0 && pbp->bio_error == 0) {
893		G_MIRROR_LOGREQ(3, bp, "Request delivered.");
894		g_destroy_bio(bp);
895		if (pbp->bio_children == pbp->bio_inbed) {
896			G_MIRROR_LOGREQ(3, pbp, "Request delivered.");
897			pbp->bio_completed = pbp->bio_length;
898			if (pbp->bio_cmd == BIO_WRITE ||
899			    pbp->bio_cmd == BIO_DELETE) {
900				bioq_remove(&sc->sc_inflight, pbp);
901				/* Release delayed sync requests if possible. */
902				g_mirror_sync_release(sc);
903			}
904			g_io_deliver(pbp, pbp->bio_error);
905		}
906		return;
907	} else if (bp->bio_error != 0) {
908		if (pbp->bio_error == 0)
909			pbp->bio_error = bp->bio_error;
910		if (disk != NULL) {
911			if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
912				disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
913				G_MIRROR_LOGREQ(0, bp,
914				    "Request failed (error=%d).",
915				    bp->bio_error);
916			} else {
917				G_MIRROR_LOGREQ(1, bp,
918				    "Request failed (error=%d).",
919				    bp->bio_error);
920			}
921			if (g_mirror_disconnect_on_failure &&
922			    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1)
923			{
924				sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
925				g_mirror_event_send(disk,
926				    G_MIRROR_DISK_STATE_DISCONNECTED,
927				    G_MIRROR_EVENT_DONTWAIT);
928			}
929		}
930		switch (pbp->bio_cmd) {
931		case BIO_DELETE:
932		case BIO_WRITE:
933			pbp->bio_inbed--;
934			pbp->bio_children--;
935			break;
936		}
937	}
938	g_destroy_bio(bp);
939
940	switch (pbp->bio_cmd) {
941	case BIO_READ:
942		if (pbp->bio_inbed < pbp->bio_children)
943			break;
944		if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 1)
945			g_io_deliver(pbp, pbp->bio_error);
946		else {
947			pbp->bio_error = 0;
948			mtx_lock(&sc->sc_queue_mtx);
949			bioq_disksort(&sc->sc_queue, pbp);
950			mtx_unlock(&sc->sc_queue_mtx);
951			G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
952			wakeup(sc);
953		}
954		break;
955	case BIO_DELETE:
956	case BIO_WRITE:
957		if (pbp->bio_children == 0) {
958			/*
959			 * All requests failed.
960			 */
961		} else if (pbp->bio_inbed < pbp->bio_children) {
962			/* Do nothing. */
963			break;
964		} else if (pbp->bio_children == pbp->bio_inbed) {
965			/* Some requests succeeded. */
966			pbp->bio_error = 0;
967			pbp->bio_completed = pbp->bio_length;
968		}
969		bioq_remove(&sc->sc_inflight, pbp);
970		/* Release delayed sync requests if possible. */
971		g_mirror_sync_release(sc);
972		g_io_deliver(pbp, pbp->bio_error);
973		break;
974	default:
975		KASSERT(1 == 0, ("Invalid request: %u.", pbp->bio_cmd));
976		break;
977	}
978}
979
980static void
981g_mirror_sync_done(struct bio *bp)
982{
983	struct g_mirror_softc *sc;
984
985	G_MIRROR_LOGREQ(3, bp, "Synchronization request delivered.");
986	sc = bp->bio_from->geom->softc;
987	bp->bio_cflags = G_MIRROR_BIO_FLAG_SYNC;
988	mtx_lock(&sc->sc_queue_mtx);
989	bioq_disksort(&sc->sc_queue, bp);
990	mtx_unlock(&sc->sc_queue_mtx);
991	wakeup(sc);
992}
993
994static void
995g_mirror_kernel_dump(struct bio *bp)
996{
997	struct g_mirror_softc *sc;
998	struct g_mirror_disk *disk;
999	struct bio *cbp;
1000	struct g_kerneldump *gkd;
1001
1002	/*
1003	 * We configure dumping to the first component, because this component
1004	 * will be used for reading with 'prefer' balance algorithm.
1005	 * If the component with the higest priority is currently disconnected
1006	 * we will not be able to read the dump after the reboot if it will be
1007	 * connected and synchronized later. Can we do something better?
1008	 */
1009	sc = bp->bio_to->geom->softc;
1010	disk = LIST_FIRST(&sc->sc_disks);
1011
1012	gkd = (struct g_kerneldump *)bp->bio_data;
1013	if (gkd->length > bp->bio_to->mediasize)
1014		gkd->length = bp->bio_to->mediasize;
1015	cbp = g_clone_bio(bp);
1016	if (cbp == NULL) {
1017		g_io_deliver(bp, ENOMEM);
1018		return;
1019	}
1020	cbp->bio_done = g_std_done;
1021	g_io_request(cbp, disk->d_consumer);
1022	G_MIRROR_DEBUG(1, "Kernel dump will go to %s.",
1023	    g_mirror_get_diskname(disk));
1024}
1025
1026static void
1027g_mirror_flush(struct g_mirror_softc *sc, struct bio *bp)
1028{
1029	struct bio_queue_head queue;
1030	struct g_mirror_disk *disk;
1031	struct g_consumer *cp;
1032	struct bio *cbp;
1033
1034	bioq_init(&queue);
1035	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1036		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1037			continue;
1038		cbp = g_clone_bio(bp);
1039		if (cbp == NULL) {
1040			for (cbp = bioq_first(&queue); cbp != NULL;
1041			    cbp = bioq_first(&queue)) {
1042				bioq_remove(&queue, cbp);
1043				g_destroy_bio(cbp);
1044			}
1045			if (bp->bio_error == 0)
1046				bp->bio_error = ENOMEM;
1047			g_io_deliver(bp, bp->bio_error);
1048			return;
1049		}
1050		bioq_insert_tail(&queue, cbp);
1051		cbp->bio_done = g_std_done;
1052		cbp->bio_caller1 = disk;
1053		cbp->bio_to = disk->d_consumer->provider;
1054	}
1055	for (cbp = bioq_first(&queue); cbp != NULL; cbp = bioq_first(&queue)) {
1056		bioq_remove(&queue, cbp);
1057		G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1058		disk = cbp->bio_caller1;
1059		cbp->bio_caller1 = NULL;
1060		cp = disk->d_consumer;
1061		KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1062		    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1063		    cp->acr, cp->acw, cp->ace));
1064		g_io_request(cbp, disk->d_consumer);
1065	}
1066}
1067
1068static void
1069g_mirror_start(struct bio *bp)
1070{
1071	struct g_mirror_softc *sc;
1072
1073	sc = bp->bio_to->geom->softc;
1074	/*
1075	 * If sc == NULL or there are no valid disks, provider's error
1076	 * should be set and g_mirror_start() should not be called at all.
1077	 */
1078	KASSERT(sc != NULL && sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
1079	    ("Provider's error should be set (error=%d)(mirror=%s).",
1080	    bp->bio_to->error, bp->bio_to->name));
1081	G_MIRROR_LOGREQ(3, bp, "Request received.");
1082
1083	switch (bp->bio_cmd) {
1084	case BIO_READ:
1085	case BIO_WRITE:
1086	case BIO_DELETE:
1087		break;
1088	case BIO_FLUSH:
1089		g_mirror_flush(sc, bp);
1090		return;
1091	case BIO_GETATTR:
1092		if (g_handleattr_int(bp, "GEOM::candelete", 1))
1093			return;
1094		else if (strcmp("GEOM::kerneldump", bp->bio_attribute) == 0) {
1095			g_mirror_kernel_dump(bp);
1096			return;
1097		}
1098		/* FALLTHROUGH */
1099	default:
1100		g_io_deliver(bp, EOPNOTSUPP);
1101		return;
1102	}
1103	mtx_lock(&sc->sc_queue_mtx);
1104	bioq_disksort(&sc->sc_queue, bp);
1105	mtx_unlock(&sc->sc_queue_mtx);
1106	G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
1107	wakeup(sc);
1108}
1109
1110/*
1111 * Return TRUE if the given request is colliding with a in-progress
1112 * synchronization request.
1113 */
1114static int
1115g_mirror_sync_collision(struct g_mirror_softc *sc, struct bio *bp)
1116{
1117	struct g_mirror_disk *disk;
1118	struct bio *sbp;
1119	off_t rstart, rend, sstart, send;
1120	int i;
1121
1122	if (sc->sc_sync.ds_ndisks == 0)
1123		return (0);
1124	rstart = bp->bio_offset;
1125	rend = bp->bio_offset + bp->bio_length;
1126	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1127		if (disk->d_state != G_MIRROR_DISK_STATE_SYNCHRONIZING)
1128			continue;
1129		for (i = 0; i < g_mirror_syncreqs; i++) {
1130			sbp = disk->d_sync.ds_bios[i];
1131			if (sbp == NULL)
1132				continue;
1133			sstart = sbp->bio_offset;
1134			send = sbp->bio_offset + sbp->bio_length;
1135			if (rend > sstart && rstart < send)
1136				return (1);
1137		}
1138	}
1139	return (0);
1140}
1141
1142/*
1143 * Return TRUE if the given sync request is colliding with a in-progress regular
1144 * request.
1145 */
1146static int
1147g_mirror_regular_collision(struct g_mirror_softc *sc, struct bio *sbp)
1148{
1149	off_t rstart, rend, sstart, send;
1150	struct bio *bp;
1151
1152	if (sc->sc_sync.ds_ndisks == 0)
1153		return (0);
1154	sstart = sbp->bio_offset;
1155	send = sbp->bio_offset + sbp->bio_length;
1156	TAILQ_FOREACH(bp, &sc->sc_inflight.queue, bio_queue) {
1157		rstart = bp->bio_offset;
1158		rend = bp->bio_offset + bp->bio_length;
1159		if (rend > sstart && rstart < send)
1160			return (1);
1161	}
1162	return (0);
1163}
1164
1165/*
1166 * Puts request onto delayed queue.
1167 */
1168static void
1169g_mirror_regular_delay(struct g_mirror_softc *sc, struct bio *bp)
1170{
1171
1172	G_MIRROR_LOGREQ(2, bp, "Delaying request.");
1173	bioq_insert_head(&sc->sc_regular_delayed, bp);
1174}
1175
1176/*
1177 * Puts synchronization request onto delayed queue.
1178 */
1179static void
1180g_mirror_sync_delay(struct g_mirror_softc *sc, struct bio *bp)
1181{
1182
1183	G_MIRROR_LOGREQ(2, bp, "Delaying synchronization request.");
1184	bioq_insert_tail(&sc->sc_sync_delayed, bp);
1185}
1186
1187/*
1188 * Releases delayed regular requests which don't collide anymore with sync
1189 * requests.
1190 */
1191static void
1192g_mirror_regular_release(struct g_mirror_softc *sc)
1193{
1194	struct bio *bp, *bp2;
1195
1196	TAILQ_FOREACH_SAFE(bp, &sc->sc_regular_delayed.queue, bio_queue, bp2) {
1197		if (g_mirror_sync_collision(sc, bp))
1198			continue;
1199		bioq_remove(&sc->sc_regular_delayed, bp);
1200		G_MIRROR_LOGREQ(2, bp, "Releasing delayed request (%p).", bp);
1201		mtx_lock(&sc->sc_queue_mtx);
1202		bioq_insert_head(&sc->sc_queue, bp);
1203#if 0
1204		/*
1205		 * wakeup() is not needed, because this function is called from
1206		 * the worker thread.
1207		 */
1208		wakeup(&sc->sc_queue);
1209#endif
1210		mtx_unlock(&sc->sc_queue_mtx);
1211	}
1212}
1213
1214/*
1215 * Releases delayed sync requests which don't collide anymore with regular
1216 * requests.
1217 */
1218static void
1219g_mirror_sync_release(struct g_mirror_softc *sc)
1220{
1221	struct bio *bp, *bp2;
1222
1223	TAILQ_FOREACH_SAFE(bp, &sc->sc_sync_delayed.queue, bio_queue, bp2) {
1224		if (g_mirror_regular_collision(sc, bp))
1225			continue;
1226		bioq_remove(&sc->sc_sync_delayed, bp);
1227		G_MIRROR_LOGREQ(2, bp,
1228		    "Releasing delayed synchronization request.");
1229		g_io_request(bp, bp->bio_from);
1230	}
1231}
1232
1233/*
1234 * Handle synchronization requests.
1235 * Every synchronization request is two-steps process: first, READ request is
1236 * send to active provider and then WRITE request (with read data) to the provider
1237 * beeing synchronized. When WRITE is finished, new synchronization request is
1238 * send.
1239 */
1240static void
1241g_mirror_sync_request(struct bio *bp)
1242{
1243	struct g_mirror_softc *sc;
1244	struct g_mirror_disk *disk;
1245
1246	bp->bio_from->index--;
1247	sc = bp->bio_from->geom->softc;
1248	disk = bp->bio_from->private;
1249	if (disk == NULL) {
1250		sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
1251		g_topology_lock();
1252		g_mirror_kill_consumer(sc, bp->bio_from);
1253		g_topology_unlock();
1254		free(bp->bio_data, M_MIRROR);
1255		g_destroy_bio(bp);
1256		sx_xlock(&sc->sc_lock);
1257		return;
1258	}
1259
1260	/*
1261	 * Synchronization request.
1262	 */
1263	switch (bp->bio_cmd) {
1264	case BIO_READ:
1265	    {
1266		struct g_consumer *cp;
1267
1268		if (bp->bio_error != 0) {
1269			G_MIRROR_LOGREQ(0, bp,
1270			    "Synchronization request failed (error=%d).",
1271			    bp->bio_error);
1272			g_destroy_bio(bp);
1273			return;
1274		}
1275		G_MIRROR_LOGREQ(3, bp,
1276		    "Synchronization request half-finished.");
1277		bp->bio_cmd = BIO_WRITE;
1278		bp->bio_cflags = 0;
1279		cp = disk->d_consumer;
1280		KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1281		    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1282		    cp->acr, cp->acw, cp->ace));
1283		cp->index++;
1284		g_io_request(bp, cp);
1285		return;
1286	    }
1287	case BIO_WRITE:
1288	    {
1289		struct g_mirror_disk_sync *sync;
1290		off_t offset;
1291		void *data;
1292		int i;
1293
1294		if (bp->bio_error != 0) {
1295			G_MIRROR_LOGREQ(0, bp,
1296			    "Synchronization request failed (error=%d).",
1297			    bp->bio_error);
1298			g_destroy_bio(bp);
1299			sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
1300			g_mirror_event_send(disk,
1301			    G_MIRROR_DISK_STATE_DISCONNECTED,
1302			    G_MIRROR_EVENT_DONTWAIT);
1303			return;
1304		}
1305		G_MIRROR_LOGREQ(3, bp, "Synchronization request finished.");
1306		sync = &disk->d_sync;
1307		if (sync->ds_offset == sc->sc_mediasize ||
1308		    sync->ds_consumer == NULL ||
1309		    (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1310			/* Don't send more synchronization requests. */
1311			sync->ds_inflight--;
1312			if (sync->ds_bios != NULL) {
1313				i = (int)(uintptr_t)bp->bio_caller1;
1314				sync->ds_bios[i] = NULL;
1315			}
1316			free(bp->bio_data, M_MIRROR);
1317			g_destroy_bio(bp);
1318			if (sync->ds_inflight > 0)
1319				return;
1320			if (sync->ds_consumer == NULL ||
1321			    (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1322				return;
1323			}
1324			/* Disk up-to-date, activate it. */
1325			g_mirror_event_send(disk, G_MIRROR_DISK_STATE_ACTIVE,
1326			    G_MIRROR_EVENT_DONTWAIT);
1327			return;
1328		}
1329
1330		/* Send next synchronization request. */
1331		data = bp->bio_data;
1332		bzero(bp, sizeof(*bp));
1333		bp->bio_cmd = BIO_READ;
1334		bp->bio_offset = sync->ds_offset;
1335		bp->bio_length = MIN(MAXPHYS, sc->sc_mediasize - bp->bio_offset);
1336		sync->ds_offset += bp->bio_length;
1337		bp->bio_done = g_mirror_sync_done;
1338		bp->bio_data = data;
1339		bp->bio_from = sync->ds_consumer;
1340		bp->bio_to = sc->sc_provider;
1341		G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
1342		sync->ds_consumer->index++;
1343		/*
1344		 * Delay the request if it is colliding with a regular request.
1345		 */
1346		if (g_mirror_regular_collision(sc, bp))
1347			g_mirror_sync_delay(sc, bp);
1348		else
1349			g_io_request(bp, sync->ds_consumer);
1350
1351		/* Release delayed requests if possible. */
1352		g_mirror_regular_release(sc);
1353
1354		/* Find the smallest offset */
1355		offset = sc->sc_mediasize;
1356		for (i = 0; i < g_mirror_syncreqs; i++) {
1357			bp = sync->ds_bios[i];
1358			if (bp->bio_offset < offset)
1359				offset = bp->bio_offset;
1360		}
1361		if (sync->ds_offset_done + (MAXPHYS * 100) < offset) {
1362			/* Update offset_done on every 100 blocks. */
1363			sync->ds_offset_done = offset;
1364			g_mirror_update_metadata(disk);
1365		}
1366		return;
1367	    }
1368	default:
1369		KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
1370		    bp->bio_cmd, sc->sc_name));
1371		break;
1372	}
1373}
1374
1375static void
1376g_mirror_request_prefer(struct g_mirror_softc *sc, struct bio *bp)
1377{
1378	struct g_mirror_disk *disk;
1379	struct g_consumer *cp;
1380	struct bio *cbp;
1381
1382	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1383		if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE)
1384			break;
1385	}
1386	if (disk == NULL) {
1387		if (bp->bio_error == 0)
1388			bp->bio_error = ENXIO;
1389		g_io_deliver(bp, bp->bio_error);
1390		return;
1391	}
1392	cbp = g_clone_bio(bp);
1393	if (cbp == NULL) {
1394		if (bp->bio_error == 0)
1395			bp->bio_error = ENOMEM;
1396		g_io_deliver(bp, bp->bio_error);
1397		return;
1398	}
1399	/*
1400	 * Fill in the component buf structure.
1401	 */
1402	cp = disk->d_consumer;
1403	cbp->bio_done = g_mirror_done;
1404	cbp->bio_to = cp->provider;
1405	G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1406	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1407	    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1408	    cp->acw, cp->ace));
1409	cp->index++;
1410	g_io_request(cbp, cp);
1411}
1412
1413static void
1414g_mirror_request_round_robin(struct g_mirror_softc *sc, struct bio *bp)
1415{
1416	struct g_mirror_disk *disk;
1417	struct g_consumer *cp;
1418	struct bio *cbp;
1419
1420	disk = g_mirror_get_disk(sc);
1421	if (disk == NULL) {
1422		if (bp->bio_error == 0)
1423			bp->bio_error = ENXIO;
1424		g_io_deliver(bp, bp->bio_error);
1425		return;
1426	}
1427	cbp = g_clone_bio(bp);
1428	if (cbp == NULL) {
1429		if (bp->bio_error == 0)
1430			bp->bio_error = ENOMEM;
1431		g_io_deliver(bp, bp->bio_error);
1432		return;
1433	}
1434	/*
1435	 * Fill in the component buf structure.
1436	 */
1437	cp = disk->d_consumer;
1438	cbp->bio_done = g_mirror_done;
1439	cbp->bio_to = cp->provider;
1440	G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1441	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1442	    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1443	    cp->acw, cp->ace));
1444	cp->index++;
1445	g_io_request(cbp, cp);
1446}
1447
1448#define TRACK_SIZE  (1 * 1024 * 1024)
1449#define LOAD_SCALE	256
1450#define ABS(x)		(((x) >= 0) ? (x) : (-(x)))
1451
1452static void
1453g_mirror_request_load(struct g_mirror_softc *sc, struct bio *bp)
1454{
1455	struct g_mirror_disk *disk, *dp;
1456	struct g_consumer *cp;
1457	struct bio *cbp;
1458	int prio, best;
1459
1460	/* Find a disk with the smallest load. */
1461	disk = NULL;
1462	best = INT_MAX;
1463	LIST_FOREACH(dp, &sc->sc_disks, d_next) {
1464		if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1465			continue;
1466		prio = dp->load;
1467		/* If disk head is precisely in position - highly prefer it. */
1468		if (dp->d_last_offset == bp->bio_offset)
1469			prio -= 2 * LOAD_SCALE;
1470		else
1471		/* If disk head is close to position - prefer it. */
1472		if (ABS(dp->d_last_offset - bp->bio_offset) < TRACK_SIZE)
1473			prio -= 1 * LOAD_SCALE;
1474		if (prio <= best) {
1475			disk = dp;
1476			best = prio;
1477		}
1478	}
1479	KASSERT(disk != NULL, ("NULL disk for %s.", sc->sc_name));
1480	cbp = g_clone_bio(bp);
1481	if (cbp == NULL) {
1482		if (bp->bio_error == 0)
1483			bp->bio_error = ENOMEM;
1484		g_io_deliver(bp, bp->bio_error);
1485		return;
1486	}
1487	/*
1488	 * Fill in the component buf structure.
1489	 */
1490	cp = disk->d_consumer;
1491	cbp->bio_done = g_mirror_done;
1492	cbp->bio_to = cp->provider;
1493	G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1494	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1495	    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1496	    cp->acw, cp->ace));
1497	cp->index++;
1498	/* Remember last head position */
1499	disk->d_last_offset = bp->bio_offset + bp->bio_length;
1500	/* Update loads. */
1501	LIST_FOREACH(dp, &sc->sc_disks, d_next) {
1502		dp->load = (dp->d_consumer->index * LOAD_SCALE +
1503		    dp->load * 7) / 8;
1504	}
1505	g_io_request(cbp, cp);
1506}
1507
1508static void
1509g_mirror_request_split(struct g_mirror_softc *sc, struct bio *bp)
1510{
1511	struct bio_queue_head queue;
1512	struct g_mirror_disk *disk;
1513	struct g_consumer *cp;
1514	struct bio *cbp;
1515	off_t left, mod, offset, slice;
1516	u_char *data;
1517	u_int ndisks;
1518
1519	if (bp->bio_length <= sc->sc_slice) {
1520		g_mirror_request_round_robin(sc, bp);
1521		return;
1522	}
1523	ndisks = g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE);
1524	slice = bp->bio_length / ndisks;
1525	mod = slice % sc->sc_provider->sectorsize;
1526	if (mod != 0)
1527		slice += sc->sc_provider->sectorsize - mod;
1528	/*
1529	 * Allocate all bios before sending any request, so we can
1530	 * return ENOMEM in nice and clean way.
1531	 */
1532	left = bp->bio_length;
1533	offset = bp->bio_offset;
1534	data = bp->bio_data;
1535	bioq_init(&queue);
1536	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1537		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1538			continue;
1539		cbp = g_clone_bio(bp);
1540		if (cbp == NULL) {
1541			for (cbp = bioq_first(&queue); cbp != NULL;
1542			    cbp = bioq_first(&queue)) {
1543				bioq_remove(&queue, cbp);
1544				g_destroy_bio(cbp);
1545			}
1546			if (bp->bio_error == 0)
1547				bp->bio_error = ENOMEM;
1548			g_io_deliver(bp, bp->bio_error);
1549			return;
1550		}
1551		bioq_insert_tail(&queue, cbp);
1552		cbp->bio_done = g_mirror_done;
1553		cbp->bio_caller1 = disk;
1554		cbp->bio_to = disk->d_consumer->provider;
1555		cbp->bio_offset = offset;
1556		cbp->bio_data = data;
1557		cbp->bio_length = MIN(left, slice);
1558		left -= cbp->bio_length;
1559		if (left == 0)
1560			break;
1561		offset += cbp->bio_length;
1562		data += cbp->bio_length;
1563	}
1564	for (cbp = bioq_first(&queue); cbp != NULL; cbp = bioq_first(&queue)) {
1565		bioq_remove(&queue, cbp);
1566		G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1567		disk = cbp->bio_caller1;
1568		cbp->bio_caller1 = NULL;
1569		cp = disk->d_consumer;
1570		KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1571		    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1572		    cp->acr, cp->acw, cp->ace));
1573		disk->d_consumer->index++;
1574		g_io_request(cbp, disk->d_consumer);
1575	}
1576}
1577
1578static void
1579g_mirror_register_request(struct bio *bp)
1580{
1581	struct g_mirror_softc *sc;
1582
1583	sc = bp->bio_to->geom->softc;
1584	switch (bp->bio_cmd) {
1585	case BIO_READ:
1586		switch (sc->sc_balance) {
1587		case G_MIRROR_BALANCE_LOAD:
1588			g_mirror_request_load(sc, bp);
1589			break;
1590		case G_MIRROR_BALANCE_PREFER:
1591			g_mirror_request_prefer(sc, bp);
1592			break;
1593		case G_MIRROR_BALANCE_ROUND_ROBIN:
1594			g_mirror_request_round_robin(sc, bp);
1595			break;
1596		case G_MIRROR_BALANCE_SPLIT:
1597			g_mirror_request_split(sc, bp);
1598			break;
1599		}
1600		return;
1601	case BIO_WRITE:
1602	case BIO_DELETE:
1603	    {
1604		struct g_mirror_disk *disk;
1605		struct g_mirror_disk_sync *sync;
1606		struct bio_queue_head queue;
1607		struct g_consumer *cp;
1608		struct bio *cbp;
1609
1610		/*
1611		 * Delay the request if it is colliding with a synchronization
1612		 * request.
1613		 */
1614		if (g_mirror_sync_collision(sc, bp)) {
1615			g_mirror_regular_delay(sc, bp);
1616			return;
1617		}
1618
1619		if (sc->sc_idle)
1620			g_mirror_unidle(sc);
1621		else
1622			sc->sc_last_write = time_uptime;
1623
1624		/*
1625		 * Allocate all bios before sending any request, so we can
1626		 * return ENOMEM in nice and clean way.
1627		 */
1628		bioq_init(&queue);
1629		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1630			sync = &disk->d_sync;
1631			switch (disk->d_state) {
1632			case G_MIRROR_DISK_STATE_ACTIVE:
1633				break;
1634			case G_MIRROR_DISK_STATE_SYNCHRONIZING:
1635				if (bp->bio_offset >= sync->ds_offset)
1636					continue;
1637				break;
1638			default:
1639				continue;
1640			}
1641			if (bp->bio_cmd == BIO_DELETE &&
1642			    (disk->d_flags & G_MIRROR_DISK_FLAG_CANDELETE) == 0)
1643				continue;
1644			cbp = g_clone_bio(bp);
1645			if (cbp == NULL) {
1646				for (cbp = bioq_first(&queue); cbp != NULL;
1647				    cbp = bioq_first(&queue)) {
1648					bioq_remove(&queue, cbp);
1649					g_destroy_bio(cbp);
1650				}
1651				if (bp->bio_error == 0)
1652					bp->bio_error = ENOMEM;
1653				g_io_deliver(bp, bp->bio_error);
1654				return;
1655			}
1656			bioq_insert_tail(&queue, cbp);
1657			cbp->bio_done = g_mirror_done;
1658			cp = disk->d_consumer;
1659			cbp->bio_caller1 = cp;
1660			cbp->bio_to = cp->provider;
1661			KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1662			    ("Consumer %s not opened (r%dw%de%d).",
1663			    cp->provider->name, cp->acr, cp->acw, cp->ace));
1664		}
1665		for (cbp = bioq_first(&queue); cbp != NULL;
1666		    cbp = bioq_first(&queue)) {
1667			bioq_remove(&queue, cbp);
1668			G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1669			cp = cbp->bio_caller1;
1670			cbp->bio_caller1 = NULL;
1671			cp->index++;
1672			sc->sc_writes++;
1673			g_io_request(cbp, cp);
1674		}
1675		/*
1676		 * Put request onto inflight queue, so we can check if new
1677		 * synchronization requests don't collide with it.
1678		 */
1679		bioq_insert_tail(&sc->sc_inflight, bp);
1680		/*
1681		 * Bump syncid on first write.
1682		 */
1683		if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0) {
1684			sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
1685			g_mirror_bump_syncid(sc);
1686		}
1687		return;
1688	    }
1689	default:
1690		KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
1691		    bp->bio_cmd, sc->sc_name));
1692		break;
1693	}
1694}
1695
1696static int
1697g_mirror_can_destroy(struct g_mirror_softc *sc)
1698{
1699	struct g_geom *gp;
1700	struct g_consumer *cp;
1701
1702	g_topology_assert();
1703	gp = sc->sc_geom;
1704	if (gp->softc == NULL)
1705		return (1);
1706	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_TASTING) != 0)
1707		return (0);
1708	LIST_FOREACH(cp, &gp->consumer, consumer) {
1709		if (g_mirror_is_busy(sc, cp))
1710			return (0);
1711	}
1712	gp = sc->sc_sync.ds_geom;
1713	LIST_FOREACH(cp, &gp->consumer, consumer) {
1714		if (g_mirror_is_busy(sc, cp))
1715			return (0);
1716	}
1717	G_MIRROR_DEBUG(2, "No I/O requests for %s, it can be destroyed.",
1718	    sc->sc_name);
1719	return (1);
1720}
1721
1722static int
1723g_mirror_try_destroy(struct g_mirror_softc *sc)
1724{
1725
1726	if (sc->sc_rootmount != NULL) {
1727		G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
1728		    sc->sc_rootmount);
1729		root_mount_rel(sc->sc_rootmount);
1730		sc->sc_rootmount = NULL;
1731	}
1732	g_topology_lock();
1733	if (!g_mirror_can_destroy(sc)) {
1734		g_topology_unlock();
1735		return (0);
1736	}
1737	sc->sc_geom->softc = NULL;
1738	sc->sc_sync.ds_geom->softc = NULL;
1739	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_WAIT) != 0) {
1740		g_topology_unlock();
1741		G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1742		    &sc->sc_worker);
1743		/* Unlock sc_lock here, as it can be destroyed after wakeup. */
1744		sx_xunlock(&sc->sc_lock);
1745		wakeup(&sc->sc_worker);
1746		sc->sc_worker = NULL;
1747	} else {
1748		g_topology_unlock();
1749		g_mirror_destroy_device(sc);
1750		free(sc, M_MIRROR);
1751	}
1752	return (1);
1753}
1754
1755/*
1756 * Worker thread.
1757 */
1758static void
1759g_mirror_worker(void *arg)
1760{
1761	struct g_mirror_softc *sc;
1762	struct g_mirror_event *ep;
1763	struct bio *bp;
1764	int timeout;
1765
1766	sc = arg;
1767	thread_lock(curthread);
1768	sched_prio(curthread, PRIBIO);
1769	thread_unlock(curthread);
1770
1771	sx_xlock(&sc->sc_lock);
1772	for (;;) {
1773		G_MIRROR_DEBUG(5, "%s: Let's see...", __func__);
1774		/*
1775		 * First take a look at events.
1776		 * This is important to handle events before any I/O requests.
1777		 */
1778		ep = g_mirror_event_get(sc);
1779		if (ep != NULL) {
1780			g_mirror_event_remove(sc, ep);
1781			if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0) {
1782				/* Update only device status. */
1783				G_MIRROR_DEBUG(3,
1784				    "Running event for device %s.",
1785				    sc->sc_name);
1786				ep->e_error = 0;
1787				g_mirror_update_device(sc, 1);
1788			} else {
1789				/* Update disk status. */
1790				G_MIRROR_DEBUG(3, "Running event for disk %s.",
1791				     g_mirror_get_diskname(ep->e_disk));
1792				ep->e_error = g_mirror_update_disk(ep->e_disk,
1793				    ep->e_state);
1794				if (ep->e_error == 0)
1795					g_mirror_update_device(sc, 0);
1796			}
1797			if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0) {
1798				KASSERT(ep->e_error == 0,
1799				    ("Error cannot be handled."));
1800				g_mirror_event_free(ep);
1801			} else {
1802				ep->e_flags |= G_MIRROR_EVENT_DONE;
1803				G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1804				    ep);
1805				mtx_lock(&sc->sc_events_mtx);
1806				wakeup(ep);
1807				mtx_unlock(&sc->sc_events_mtx);
1808			}
1809			if ((sc->sc_flags &
1810			    G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1811				if (g_mirror_try_destroy(sc)) {
1812					curthread->td_pflags &= ~TDP_GEOM;
1813					G_MIRROR_DEBUG(1, "Thread exiting.");
1814					kproc_exit(0);
1815				}
1816			}
1817			G_MIRROR_DEBUG(5, "%s: I'm here 1.", __func__);
1818			continue;
1819		}
1820		/*
1821		 * Check if we can mark array as CLEAN and if we can't take
1822		 * how much seconds should we wait.
1823		 */
1824		timeout = g_mirror_idle(sc, -1);
1825		/*
1826		 * Now I/O requests.
1827		 */
1828		/* Get first request from the queue. */
1829		mtx_lock(&sc->sc_queue_mtx);
1830		bp = bioq_first(&sc->sc_queue);
1831		if (bp == NULL) {
1832			if ((sc->sc_flags &
1833			    G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1834				mtx_unlock(&sc->sc_queue_mtx);
1835				if (g_mirror_try_destroy(sc)) {
1836					curthread->td_pflags &= ~TDP_GEOM;
1837					G_MIRROR_DEBUG(1, "Thread exiting.");
1838					kproc_exit(0);
1839				}
1840				mtx_lock(&sc->sc_queue_mtx);
1841			}
1842			sx_xunlock(&sc->sc_lock);
1843			/*
1844			 * XXX: We can miss an event here, because an event
1845			 *      can be added without sx-device-lock and without
1846			 *      mtx-queue-lock. Maybe I should just stop using
1847			 *      dedicated mutex for events synchronization and
1848			 *      stick with the queue lock?
1849			 *      The event will hang here until next I/O request
1850			 *      or next event is received.
1851			 */
1852			MSLEEP(sc, &sc->sc_queue_mtx, PRIBIO | PDROP, "m:w1",
1853			    timeout * hz);
1854			sx_xlock(&sc->sc_lock);
1855			G_MIRROR_DEBUG(5, "%s: I'm here 4.", __func__);
1856			continue;
1857		}
1858		bioq_remove(&sc->sc_queue, bp);
1859		mtx_unlock(&sc->sc_queue_mtx);
1860
1861		if (bp->bio_from->geom == sc->sc_sync.ds_geom &&
1862		    (bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0) {
1863			g_mirror_sync_request(bp);	/* READ */
1864		} else if (bp->bio_to != sc->sc_provider) {
1865			if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_REGULAR) != 0)
1866				g_mirror_regular_request(bp);
1867			else if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0)
1868				g_mirror_sync_request(bp);	/* WRITE */
1869			else {
1870				KASSERT(0,
1871				    ("Invalid request cflags=0x%hhx to=%s.",
1872				    bp->bio_cflags, bp->bio_to->name));
1873			}
1874		} else {
1875			g_mirror_register_request(bp);
1876		}
1877		G_MIRROR_DEBUG(5, "%s: I'm here 9.", __func__);
1878	}
1879}
1880
1881static void
1882g_mirror_update_idle(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
1883{
1884
1885	sx_assert(&sc->sc_lock, SX_LOCKED);
1886
1887	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
1888		return;
1889	if (!sc->sc_idle && (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) == 0) {
1890		G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as dirty.",
1891		    g_mirror_get_diskname(disk), sc->sc_name);
1892		disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
1893	} else if (sc->sc_idle &&
1894	    (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
1895		G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as clean.",
1896		    g_mirror_get_diskname(disk), sc->sc_name);
1897		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
1898	}
1899}
1900
1901static void
1902g_mirror_sync_start(struct g_mirror_disk *disk)
1903{
1904	struct g_mirror_softc *sc;
1905	struct g_consumer *cp;
1906	struct bio *bp;
1907	int error, i;
1908
1909	g_topology_assert_not();
1910	sc = disk->d_softc;
1911	sx_assert(&sc->sc_lock, SX_LOCKED);
1912
1913	KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
1914	    ("Disk %s is not marked for synchronization.",
1915	    g_mirror_get_diskname(disk)));
1916	KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
1917	    ("Device not in RUNNING state (%s, %u).", sc->sc_name,
1918	    sc->sc_state));
1919
1920	sx_xunlock(&sc->sc_lock);
1921	g_topology_lock();
1922	cp = g_new_consumer(sc->sc_sync.ds_geom);
1923	error = g_attach(cp, sc->sc_provider);
1924	KASSERT(error == 0,
1925	    ("Cannot attach to %s (error=%d).", sc->sc_name, error));
1926	error = g_access(cp, 1, 0, 0);
1927	KASSERT(error == 0, ("Cannot open %s (error=%d).", sc->sc_name, error));
1928	g_topology_unlock();
1929	sx_xlock(&sc->sc_lock);
1930
1931	G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s.", sc->sc_name,
1932	    g_mirror_get_diskname(disk));
1933	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) == 0)
1934		disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
1935	KASSERT(disk->d_sync.ds_consumer == NULL,
1936	    ("Sync consumer already exists (device=%s, disk=%s).",
1937	    sc->sc_name, g_mirror_get_diskname(disk)));
1938
1939	disk->d_sync.ds_consumer = cp;
1940	disk->d_sync.ds_consumer->private = disk;
1941	disk->d_sync.ds_consumer->index = 0;
1942
1943	/*
1944	 * Allocate memory for synchronization bios and initialize them.
1945	 */
1946	disk->d_sync.ds_bios = malloc(sizeof(struct bio *) * g_mirror_syncreqs,
1947	    M_MIRROR, M_WAITOK);
1948	for (i = 0; i < g_mirror_syncreqs; i++) {
1949		bp = g_alloc_bio();
1950		disk->d_sync.ds_bios[i] = bp;
1951		bp->bio_parent = NULL;
1952		bp->bio_cmd = BIO_READ;
1953		bp->bio_data = malloc(MAXPHYS, M_MIRROR, M_WAITOK);
1954		bp->bio_cflags = 0;
1955		bp->bio_offset = disk->d_sync.ds_offset;
1956		bp->bio_length = MIN(MAXPHYS, sc->sc_mediasize - bp->bio_offset);
1957		disk->d_sync.ds_offset += bp->bio_length;
1958		bp->bio_done = g_mirror_sync_done;
1959		bp->bio_from = disk->d_sync.ds_consumer;
1960		bp->bio_to = sc->sc_provider;
1961		bp->bio_caller1 = (void *)(uintptr_t)i;
1962	}
1963
1964	/* Increase the number of disks in SYNCHRONIZING state. */
1965	sc->sc_sync.ds_ndisks++;
1966	/* Set the number of in-flight synchronization requests. */
1967	disk->d_sync.ds_inflight = g_mirror_syncreqs;
1968
1969	/*
1970	 * Fire off first synchronization requests.
1971	 */
1972	for (i = 0; i < g_mirror_syncreqs; i++) {
1973		bp = disk->d_sync.ds_bios[i];
1974		G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
1975		disk->d_sync.ds_consumer->index++;
1976		/*
1977		 * Delay the request if it is colliding with a regular request.
1978		 */
1979		if (g_mirror_regular_collision(sc, bp))
1980			g_mirror_sync_delay(sc, bp);
1981		else
1982			g_io_request(bp, disk->d_sync.ds_consumer);
1983	}
1984}
1985
1986/*
1987 * Stop synchronization process.
1988 * type: 0 - synchronization finished
1989 *       1 - synchronization stopped
1990 */
1991static void
1992g_mirror_sync_stop(struct g_mirror_disk *disk, int type)
1993{
1994	struct g_mirror_softc *sc;
1995	struct g_consumer *cp;
1996
1997	g_topology_assert_not();
1998	sc = disk->d_softc;
1999	sx_assert(&sc->sc_lock, SX_LOCKED);
2000
2001	KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2002	    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2003	    g_mirror_disk_state2str(disk->d_state)));
2004	if (disk->d_sync.ds_consumer == NULL)
2005		return;
2006
2007	if (type == 0) {
2008		G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s finished.",
2009		    sc->sc_name, g_mirror_get_diskname(disk));
2010	} else /* if (type == 1) */ {
2011		G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s stopped.",
2012		    sc->sc_name, g_mirror_get_diskname(disk));
2013	}
2014	free(disk->d_sync.ds_bios, M_MIRROR);
2015	disk->d_sync.ds_bios = NULL;
2016	cp = disk->d_sync.ds_consumer;
2017	disk->d_sync.ds_consumer = NULL;
2018	disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2019	sc->sc_sync.ds_ndisks--;
2020	sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
2021	g_topology_lock();
2022	g_mirror_kill_consumer(sc, cp);
2023	g_topology_unlock();
2024	sx_xlock(&sc->sc_lock);
2025}
2026
2027static void
2028g_mirror_launch_provider(struct g_mirror_softc *sc)
2029{
2030	struct g_mirror_disk *disk;
2031	struct g_provider *pp, *dp;
2032
2033	sx_assert(&sc->sc_lock, SX_LOCKED);
2034
2035	g_topology_lock();
2036	pp = g_new_providerf(sc->sc_geom, "mirror/%s", sc->sc_name);
2037	pp->mediasize = sc->sc_mediasize;
2038	pp->sectorsize = sc->sc_sectorsize;
2039	pp->stripesize = 0;
2040	pp->stripeoffset = 0;
2041
2042	/* Splitting of unmapped BIO's could work but isn't implemented now */
2043	if (sc->sc_balance != G_MIRROR_BALANCE_SPLIT)
2044		pp->flags |= G_PF_ACCEPT_UNMAPPED;
2045
2046	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2047		if (disk->d_consumer && disk->d_consumer->provider) {
2048			dp = disk->d_consumer->provider;
2049			if (dp->stripesize > pp->stripesize) {
2050				pp->stripesize = dp->stripesize;
2051				pp->stripeoffset = dp->stripeoffset;
2052			}
2053			/* A provider underneath us doesn't support unmapped */
2054			if ((dp->flags & G_PF_ACCEPT_UNMAPPED) == 0) {
2055				G_MIRROR_DEBUG(0, "cancelling unmapped "
2056				    "because of %s\n", dp->name);
2057				pp->flags &= ~G_PF_ACCEPT_UNMAPPED;
2058			}
2059		}
2060	}
2061	sc->sc_provider = pp;
2062	g_error_provider(pp, 0);
2063	g_topology_unlock();
2064	G_MIRROR_DEBUG(0, "Device %s launched (%u/%u).", pp->name,
2065	    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE), sc->sc_ndisks);
2066	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2067		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2068			g_mirror_sync_start(disk);
2069	}
2070}
2071
2072static void
2073g_mirror_destroy_provider(struct g_mirror_softc *sc)
2074{
2075	struct g_mirror_disk *disk;
2076	struct bio *bp;
2077
2078	g_topology_assert_not();
2079	KASSERT(sc->sc_provider != NULL, ("NULL provider (device=%s).",
2080	    sc->sc_name));
2081
2082	g_topology_lock();
2083	g_error_provider(sc->sc_provider, ENXIO);
2084	mtx_lock(&sc->sc_queue_mtx);
2085	while ((bp = bioq_first(&sc->sc_queue)) != NULL) {
2086		bioq_remove(&sc->sc_queue, bp);
2087		g_io_deliver(bp, ENXIO);
2088	}
2089	mtx_unlock(&sc->sc_queue_mtx);
2090	G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.", sc->sc_name,
2091	    sc->sc_provider->name);
2092	sc->sc_provider->flags |= G_PF_WITHER;
2093	g_orphan_provider(sc->sc_provider, ENXIO);
2094	g_topology_unlock();
2095	sc->sc_provider = NULL;
2096	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2097		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2098			g_mirror_sync_stop(disk, 1);
2099	}
2100}
2101
2102static void
2103g_mirror_go(void *arg)
2104{
2105	struct g_mirror_softc *sc;
2106
2107	sc = arg;
2108	G_MIRROR_DEBUG(0, "Force device %s start due to timeout.", sc->sc_name);
2109	g_mirror_event_send(sc, 0,
2110	    G_MIRROR_EVENT_DONTWAIT | G_MIRROR_EVENT_DEVICE);
2111}
2112
2113static u_int
2114g_mirror_determine_state(struct g_mirror_disk *disk)
2115{
2116	struct g_mirror_softc *sc;
2117	u_int state;
2118
2119	sc = disk->d_softc;
2120	if (sc->sc_syncid == disk->d_sync.ds_syncid) {
2121		if ((disk->d_flags &
2122		    G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2123			/* Disk does not need synchronization. */
2124			state = G_MIRROR_DISK_STATE_ACTIVE;
2125		} else {
2126			if ((sc->sc_flags &
2127			     G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2128			    (disk->d_flags &
2129			     G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2130				/*
2131				 * We can start synchronization from
2132				 * the stored offset.
2133				 */
2134				state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2135			} else {
2136				state = G_MIRROR_DISK_STATE_STALE;
2137			}
2138		}
2139	} else if (disk->d_sync.ds_syncid < sc->sc_syncid) {
2140		/*
2141		 * Reset all synchronization data for this disk,
2142		 * because if it even was synchronized, it was
2143		 * synchronized to disks with different syncid.
2144		 */
2145		disk->d_flags |= G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2146		disk->d_sync.ds_offset = 0;
2147		disk->d_sync.ds_offset_done = 0;
2148		disk->d_sync.ds_syncid = sc->sc_syncid;
2149		if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2150		    (disk->d_flags & G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2151			state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2152		} else {
2153			state = G_MIRROR_DISK_STATE_STALE;
2154		}
2155	} else /* if (sc->sc_syncid < disk->d_sync.ds_syncid) */ {
2156		/*
2157		 * Not good, NOT GOOD!
2158		 * It means that mirror was started on stale disks
2159		 * and more fresh disk just arrive.
2160		 * If there were writes, mirror is broken, sorry.
2161		 * I think the best choice here is don't touch
2162		 * this disk and inform the user loudly.
2163		 */
2164		G_MIRROR_DEBUG(0, "Device %s was started before the freshest "
2165		    "disk (%s) arrives!! It will not be connected to the "
2166		    "running device.", sc->sc_name,
2167		    g_mirror_get_diskname(disk));
2168		g_mirror_destroy_disk(disk);
2169		state = G_MIRROR_DISK_STATE_NONE;
2170		/* Return immediately, because disk was destroyed. */
2171		return (state);
2172	}
2173	G_MIRROR_DEBUG(3, "State for %s disk: %s.",
2174	    g_mirror_get_diskname(disk), g_mirror_disk_state2str(state));
2175	return (state);
2176}
2177
2178/*
2179 * Update device state.
2180 */
2181static void
2182g_mirror_update_device(struct g_mirror_softc *sc, boolean_t force)
2183{
2184	struct g_mirror_disk *disk;
2185	u_int state;
2186
2187	sx_assert(&sc->sc_lock, SX_XLOCKED);
2188
2189	switch (sc->sc_state) {
2190	case G_MIRROR_DEVICE_STATE_STARTING:
2191	    {
2192		struct g_mirror_disk *pdisk, *tdisk;
2193		u_int dirty, ndisks, genid, syncid;
2194
2195		KASSERT(sc->sc_provider == NULL,
2196		    ("Non-NULL provider in STARTING state (%s).", sc->sc_name));
2197		/*
2198		 * Are we ready? We are, if all disks are connected or
2199		 * if we have any disks and 'force' is true.
2200		 */
2201		ndisks = g_mirror_ndisks(sc, -1);
2202		if (sc->sc_ndisks == ndisks || (force && ndisks > 0)) {
2203			;
2204		} else if (ndisks == 0) {
2205			/*
2206			 * Disks went down in starting phase, so destroy
2207			 * device.
2208			 */
2209			callout_drain(&sc->sc_callout);
2210			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2211			G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
2212			    sc->sc_rootmount);
2213			root_mount_rel(sc->sc_rootmount);
2214			sc->sc_rootmount = NULL;
2215			return;
2216		} else {
2217			return;
2218		}
2219
2220		/*
2221		 * Activate all disks with the biggest syncid.
2222		 */
2223		if (force) {
2224			/*
2225			 * If 'force' is true, we have been called due to
2226			 * timeout, so don't bother canceling timeout.
2227			 */
2228			ndisks = 0;
2229			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2230				if ((disk->d_flags &
2231				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2232					ndisks++;
2233				}
2234			}
2235			if (ndisks == 0) {
2236				/* No valid disks found, destroy device. */
2237				sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2238				G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2239				    __LINE__, sc->sc_rootmount);
2240				root_mount_rel(sc->sc_rootmount);
2241				sc->sc_rootmount = NULL;
2242				return;
2243			}
2244		} else {
2245			/* Cancel timeout. */
2246			callout_drain(&sc->sc_callout);
2247		}
2248
2249		/*
2250		 * Find the biggest genid.
2251		 */
2252		genid = 0;
2253		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2254			if (disk->d_genid > genid)
2255				genid = disk->d_genid;
2256		}
2257		sc->sc_genid = genid;
2258		/*
2259		 * Remove all disks without the biggest genid.
2260		 */
2261		LIST_FOREACH_SAFE(disk, &sc->sc_disks, d_next, tdisk) {
2262			if (disk->d_genid < genid) {
2263				G_MIRROR_DEBUG(0,
2264				    "Component %s (device %s) broken, skipping.",
2265				    g_mirror_get_diskname(disk), sc->sc_name);
2266				g_mirror_destroy_disk(disk);
2267			}
2268		}
2269
2270		/*
2271		 * Find the biggest syncid.
2272		 */
2273		syncid = 0;
2274		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2275			if (disk->d_sync.ds_syncid > syncid)
2276				syncid = disk->d_sync.ds_syncid;
2277		}
2278
2279		/*
2280		 * Here we need to look for dirty disks and if all disks
2281		 * with the biggest syncid are dirty, we have to choose
2282		 * one with the biggest priority and rebuild the rest.
2283		 */
2284		/*
2285		 * Find the number of dirty disks with the biggest syncid.
2286		 * Find the number of disks with the biggest syncid.
2287		 * While here, find a disk with the biggest priority.
2288		 */
2289		dirty = ndisks = 0;
2290		pdisk = NULL;
2291		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2292			if (disk->d_sync.ds_syncid != syncid)
2293				continue;
2294			if ((disk->d_flags &
2295			    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2296				continue;
2297			}
2298			ndisks++;
2299			if ((disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
2300				dirty++;
2301				if (pdisk == NULL ||
2302				    pdisk->d_priority < disk->d_priority) {
2303					pdisk = disk;
2304				}
2305			}
2306		}
2307		if (dirty == 0) {
2308			/* No dirty disks at all, great. */
2309		} else if (dirty == ndisks) {
2310			/*
2311			 * Force synchronization for all dirty disks except one
2312			 * with the biggest priority.
2313			 */
2314			KASSERT(pdisk != NULL, ("pdisk == NULL"));
2315			G_MIRROR_DEBUG(1, "Using disk %s (device %s) as a "
2316			    "master disk for synchronization.",
2317			    g_mirror_get_diskname(pdisk), sc->sc_name);
2318			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2319				if (disk->d_sync.ds_syncid != syncid)
2320					continue;
2321				if ((disk->d_flags &
2322				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2323					continue;
2324				}
2325				KASSERT((disk->d_flags &
2326				    G_MIRROR_DISK_FLAG_DIRTY) != 0,
2327				    ("Disk %s isn't marked as dirty.",
2328				    g_mirror_get_diskname(disk)));
2329				/* Skip the disk with the biggest priority. */
2330				if (disk == pdisk)
2331					continue;
2332				disk->d_sync.ds_syncid = 0;
2333			}
2334		} else if (dirty < ndisks) {
2335			/*
2336			 * Force synchronization for all dirty disks.
2337			 * We have some non-dirty disks.
2338			 */
2339			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2340				if (disk->d_sync.ds_syncid != syncid)
2341					continue;
2342				if ((disk->d_flags &
2343				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2344					continue;
2345				}
2346				if ((disk->d_flags &
2347				    G_MIRROR_DISK_FLAG_DIRTY) == 0) {
2348					continue;
2349				}
2350				disk->d_sync.ds_syncid = 0;
2351			}
2352		}
2353
2354		/* Reset hint. */
2355		sc->sc_hint = NULL;
2356		sc->sc_syncid = syncid;
2357		if (force) {
2358			/* Remember to bump syncid on first write. */
2359			sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2360		}
2361		state = G_MIRROR_DEVICE_STATE_RUNNING;
2362		G_MIRROR_DEBUG(1, "Device %s state changed from %s to %s.",
2363		    sc->sc_name, g_mirror_device_state2str(sc->sc_state),
2364		    g_mirror_device_state2str(state));
2365		sc->sc_state = state;
2366		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2367			state = g_mirror_determine_state(disk);
2368			g_mirror_event_send(disk, state,
2369			    G_MIRROR_EVENT_DONTWAIT);
2370			if (state == G_MIRROR_DISK_STATE_STALE)
2371				sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2372		}
2373		break;
2374	    }
2375	case G_MIRROR_DEVICE_STATE_RUNNING:
2376		if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 0 &&
2377		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2378			/*
2379			 * No active disks or no disks at all,
2380			 * so destroy device.
2381			 */
2382			if (sc->sc_provider != NULL)
2383				g_mirror_destroy_provider(sc);
2384			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2385			break;
2386		} else if (g_mirror_ndisks(sc,
2387		    G_MIRROR_DISK_STATE_ACTIVE) > 0 &&
2388		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2389			/*
2390			 * We have active disks, launch provider if it doesn't
2391			 * exist.
2392			 */
2393			if (sc->sc_provider == NULL)
2394				g_mirror_launch_provider(sc);
2395			if (sc->sc_rootmount != NULL) {
2396				G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2397				    __LINE__, sc->sc_rootmount);
2398				root_mount_rel(sc->sc_rootmount);
2399				sc->sc_rootmount = NULL;
2400			}
2401		}
2402		/*
2403		 * Genid should be bumped immediately, so do it here.
2404		 */
2405		if ((sc->sc_bump_id & G_MIRROR_BUMP_GENID) != 0) {
2406			sc->sc_bump_id &= ~G_MIRROR_BUMP_GENID;
2407			g_mirror_bump_genid(sc);
2408		}
2409		break;
2410	default:
2411		KASSERT(1 == 0, ("Wrong device state (%s, %s).",
2412		    sc->sc_name, g_mirror_device_state2str(sc->sc_state)));
2413		break;
2414	}
2415}
2416
2417/*
2418 * Update disk state and device state if needed.
2419 */
2420#define	DISK_STATE_CHANGED()	G_MIRROR_DEBUG(1,			\
2421	"Disk %s state changed from %s to %s (device %s).",		\
2422	g_mirror_get_diskname(disk),					\
2423	g_mirror_disk_state2str(disk->d_state),				\
2424	g_mirror_disk_state2str(state), sc->sc_name)
2425static int
2426g_mirror_update_disk(struct g_mirror_disk *disk, u_int state)
2427{
2428	struct g_mirror_softc *sc;
2429
2430	sc = disk->d_softc;
2431	sx_assert(&sc->sc_lock, SX_XLOCKED);
2432
2433again:
2434	G_MIRROR_DEBUG(3, "Changing disk %s state from %s to %s.",
2435	    g_mirror_get_diskname(disk), g_mirror_disk_state2str(disk->d_state),
2436	    g_mirror_disk_state2str(state));
2437	switch (state) {
2438	case G_MIRROR_DISK_STATE_NEW:
2439		/*
2440		 * Possible scenarios:
2441		 * 1. New disk arrive.
2442		 */
2443		/* Previous state should be NONE. */
2444		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NONE,
2445		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2446		    g_mirror_disk_state2str(disk->d_state)));
2447		DISK_STATE_CHANGED();
2448
2449		disk->d_state = state;
2450		if (LIST_EMPTY(&sc->sc_disks))
2451			LIST_INSERT_HEAD(&sc->sc_disks, disk, d_next);
2452		else {
2453			struct g_mirror_disk *dp;
2454
2455			LIST_FOREACH(dp, &sc->sc_disks, d_next) {
2456				if (disk->d_priority >= dp->d_priority) {
2457					LIST_INSERT_BEFORE(dp, disk, d_next);
2458					dp = NULL;
2459					break;
2460				}
2461				if (LIST_NEXT(dp, d_next) == NULL)
2462					break;
2463			}
2464			if (dp != NULL)
2465				LIST_INSERT_AFTER(dp, disk, d_next);
2466		}
2467		G_MIRROR_DEBUG(1, "Device %s: provider %s detected.",
2468		    sc->sc_name, g_mirror_get_diskname(disk));
2469		if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
2470			break;
2471		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2472		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2473		    g_mirror_device_state2str(sc->sc_state),
2474		    g_mirror_get_diskname(disk),
2475		    g_mirror_disk_state2str(disk->d_state)));
2476		state = g_mirror_determine_state(disk);
2477		if (state != G_MIRROR_DISK_STATE_NONE)
2478			goto again;
2479		break;
2480	case G_MIRROR_DISK_STATE_ACTIVE:
2481		/*
2482		 * Possible scenarios:
2483		 * 1. New disk does not need synchronization.
2484		 * 2. Synchronization process finished successfully.
2485		 */
2486		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2487		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2488		    g_mirror_device_state2str(sc->sc_state),
2489		    g_mirror_get_diskname(disk),
2490		    g_mirror_disk_state2str(disk->d_state)));
2491		/* Previous state should be NEW or SYNCHRONIZING. */
2492		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW ||
2493		    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2494		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2495		    g_mirror_disk_state2str(disk->d_state)));
2496		DISK_STATE_CHANGED();
2497
2498		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
2499			disk->d_flags &= ~G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2500			disk->d_flags &= ~G_MIRROR_DISK_FLAG_FORCE_SYNC;
2501			g_mirror_sync_stop(disk, 0);
2502		}
2503		disk->d_state = state;
2504		disk->d_sync.ds_offset = 0;
2505		disk->d_sync.ds_offset_done = 0;
2506		g_mirror_update_idle(sc, disk);
2507		g_mirror_update_metadata(disk);
2508		G_MIRROR_DEBUG(1, "Device %s: provider %s activated.",
2509		    sc->sc_name, g_mirror_get_diskname(disk));
2510		break;
2511	case G_MIRROR_DISK_STATE_STALE:
2512		/*
2513		 * Possible scenarios:
2514		 * 1. Stale disk was connected.
2515		 */
2516		/* Previous state should be NEW. */
2517		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2518		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2519		    g_mirror_disk_state2str(disk->d_state)));
2520		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2521		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2522		    g_mirror_device_state2str(sc->sc_state),
2523		    g_mirror_get_diskname(disk),
2524		    g_mirror_disk_state2str(disk->d_state)));
2525		/*
2526		 * STALE state is only possible if device is marked
2527		 * NOAUTOSYNC.
2528		 */
2529		KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0,
2530		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2531		    g_mirror_device_state2str(sc->sc_state),
2532		    g_mirror_get_diskname(disk),
2533		    g_mirror_disk_state2str(disk->d_state)));
2534		DISK_STATE_CHANGED();
2535
2536		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2537		disk->d_state = state;
2538		g_mirror_update_metadata(disk);
2539		G_MIRROR_DEBUG(0, "Device %s: provider %s is stale.",
2540		    sc->sc_name, g_mirror_get_diskname(disk));
2541		break;
2542	case G_MIRROR_DISK_STATE_SYNCHRONIZING:
2543		/*
2544		 * Possible scenarios:
2545		 * 1. Disk which needs synchronization was connected.
2546		 */
2547		/* Previous state should be NEW. */
2548		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2549		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2550		    g_mirror_disk_state2str(disk->d_state)));
2551		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2552		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2553		    g_mirror_device_state2str(sc->sc_state),
2554		    g_mirror_get_diskname(disk),
2555		    g_mirror_disk_state2str(disk->d_state)));
2556		DISK_STATE_CHANGED();
2557
2558		if (disk->d_state == G_MIRROR_DISK_STATE_NEW)
2559			disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2560		disk->d_state = state;
2561		if (sc->sc_provider != NULL) {
2562			g_mirror_sync_start(disk);
2563			g_mirror_update_metadata(disk);
2564		}
2565		break;
2566	case G_MIRROR_DISK_STATE_DISCONNECTED:
2567		/*
2568		 * Possible scenarios:
2569		 * 1. Device wasn't running yet, but disk disappear.
2570		 * 2. Disk was active and disapppear.
2571		 * 3. Disk disappear during synchronization process.
2572		 */
2573		if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING) {
2574			/*
2575			 * Previous state should be ACTIVE, STALE or
2576			 * SYNCHRONIZING.
2577			 */
2578			KASSERT(disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
2579			    disk->d_state == G_MIRROR_DISK_STATE_STALE ||
2580			    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2581			    ("Wrong disk state (%s, %s).",
2582			    g_mirror_get_diskname(disk),
2583			    g_mirror_disk_state2str(disk->d_state)));
2584		} else if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING) {
2585			/* Previous state should be NEW. */
2586			KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2587			    ("Wrong disk state (%s, %s).",
2588			    g_mirror_get_diskname(disk),
2589			    g_mirror_disk_state2str(disk->d_state)));
2590			/*
2591			 * Reset bumping syncid if disk disappeared in STARTING
2592			 * state.
2593			 */
2594			if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0)
2595				sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
2596#ifdef	INVARIANTS
2597		} else {
2598			KASSERT(1 == 0, ("Wrong device state (%s, %s, %s, %s).",
2599			    sc->sc_name,
2600			    g_mirror_device_state2str(sc->sc_state),
2601			    g_mirror_get_diskname(disk),
2602			    g_mirror_disk_state2str(disk->d_state)));
2603#endif
2604		}
2605		DISK_STATE_CHANGED();
2606		G_MIRROR_DEBUG(0, "Device %s: provider %s disconnected.",
2607		    sc->sc_name, g_mirror_get_diskname(disk));
2608
2609		g_mirror_destroy_disk(disk);
2610		break;
2611	case G_MIRROR_DISK_STATE_DESTROY:
2612	    {
2613		int error;
2614
2615		error = g_mirror_clear_metadata(disk);
2616		if (error != 0)
2617			return (error);
2618		DISK_STATE_CHANGED();
2619		G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.",
2620		    sc->sc_name, g_mirror_get_diskname(disk));
2621
2622		g_mirror_destroy_disk(disk);
2623		sc->sc_ndisks--;
2624		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2625			g_mirror_update_metadata(disk);
2626		}
2627		break;
2628	    }
2629	default:
2630		KASSERT(1 == 0, ("Unknown state (%u).", state));
2631		break;
2632	}
2633	return (0);
2634}
2635#undef	DISK_STATE_CHANGED
2636
2637int
2638g_mirror_read_metadata(struct g_consumer *cp, struct g_mirror_metadata *md)
2639{
2640	struct g_provider *pp;
2641	u_char *buf;
2642	int error;
2643
2644	g_topology_assert();
2645
2646	error = g_access(cp, 1, 0, 0);
2647	if (error != 0)
2648		return (error);
2649	pp = cp->provider;
2650	g_topology_unlock();
2651	/* Metadata are stored on last sector. */
2652	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
2653	    &error);
2654	g_topology_lock();
2655	g_access(cp, -1, 0, 0);
2656	if (buf == NULL) {
2657		G_MIRROR_DEBUG(1, "Cannot read metadata from %s (error=%d).",
2658		    cp->provider->name, error);
2659		return (error);
2660	}
2661
2662	/* Decode metadata. */
2663	error = mirror_metadata_decode(buf, md);
2664	g_free(buf);
2665	if (strcmp(md->md_magic, G_MIRROR_MAGIC) != 0)
2666		return (EINVAL);
2667	if (md->md_version > G_MIRROR_VERSION) {
2668		G_MIRROR_DEBUG(0,
2669		    "Kernel module is too old to handle metadata from %s.",
2670		    cp->provider->name);
2671		return (EINVAL);
2672	}
2673	if (error != 0) {
2674		G_MIRROR_DEBUG(1, "MD5 metadata hash mismatch for provider %s.",
2675		    cp->provider->name);
2676		return (error);
2677	}
2678
2679	return (0);
2680}
2681
2682static int
2683g_mirror_check_metadata(struct g_mirror_softc *sc, struct g_provider *pp,
2684    struct g_mirror_metadata *md)
2685{
2686
2687	if (g_mirror_id2disk(sc, md->md_did) != NULL) {
2688		G_MIRROR_DEBUG(1, "Disk %s (id=%u) already exists, skipping.",
2689		    pp->name, md->md_did);
2690		return (EEXIST);
2691	}
2692	if (md->md_all != sc->sc_ndisks) {
2693		G_MIRROR_DEBUG(1,
2694		    "Invalid '%s' field on disk %s (device %s), skipping.",
2695		    "md_all", pp->name, sc->sc_name);
2696		return (EINVAL);
2697	}
2698	if (md->md_slice != sc->sc_slice) {
2699		G_MIRROR_DEBUG(1,
2700		    "Invalid '%s' field on disk %s (device %s), skipping.",
2701		    "md_slice", pp->name, sc->sc_name);
2702		return (EINVAL);
2703	}
2704	if (md->md_balance != sc->sc_balance) {
2705		G_MIRROR_DEBUG(1,
2706		    "Invalid '%s' field on disk %s (device %s), skipping.",
2707		    "md_balance", pp->name, sc->sc_name);
2708		return (EINVAL);
2709	}
2710	if (md->md_mediasize != sc->sc_mediasize) {
2711		G_MIRROR_DEBUG(1,
2712		    "Invalid '%s' field on disk %s (device %s), skipping.",
2713		    "md_mediasize", pp->name, sc->sc_name);
2714		return (EINVAL);
2715	}
2716	if (sc->sc_mediasize > pp->mediasize) {
2717		G_MIRROR_DEBUG(1,
2718		    "Invalid size of disk %s (device %s), skipping.", pp->name,
2719		    sc->sc_name);
2720		return (EINVAL);
2721	}
2722	if (md->md_sectorsize != sc->sc_sectorsize) {
2723		G_MIRROR_DEBUG(1,
2724		    "Invalid '%s' field on disk %s (device %s), skipping.",
2725		    "md_sectorsize", pp->name, sc->sc_name);
2726		return (EINVAL);
2727	}
2728	if ((sc->sc_sectorsize % pp->sectorsize) != 0) {
2729		G_MIRROR_DEBUG(1,
2730		    "Invalid sector size of disk %s (device %s), skipping.",
2731		    pp->name, sc->sc_name);
2732		return (EINVAL);
2733	}
2734	if ((md->md_mflags & ~G_MIRROR_DEVICE_FLAG_MASK) != 0) {
2735		G_MIRROR_DEBUG(1,
2736		    "Invalid device flags on disk %s (device %s), skipping.",
2737		    pp->name, sc->sc_name);
2738		return (EINVAL);
2739	}
2740	if ((md->md_dflags & ~G_MIRROR_DISK_FLAG_MASK) != 0) {
2741		G_MIRROR_DEBUG(1,
2742		    "Invalid disk flags on disk %s (device %s), skipping.",
2743		    pp->name, sc->sc_name);
2744		return (EINVAL);
2745	}
2746	return (0);
2747}
2748
2749int
2750g_mirror_add_disk(struct g_mirror_softc *sc, struct g_provider *pp,
2751    struct g_mirror_metadata *md)
2752{
2753	struct g_mirror_disk *disk;
2754	int error;
2755
2756	g_topology_assert_not();
2757	G_MIRROR_DEBUG(2, "Adding disk %s.", pp->name);
2758
2759	error = g_mirror_check_metadata(sc, pp, md);
2760	if (error != 0)
2761		return (error);
2762	if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING &&
2763	    md->md_genid < sc->sc_genid) {
2764		G_MIRROR_DEBUG(0, "Component %s (device %s) broken, skipping.",
2765		    pp->name, sc->sc_name);
2766		return (EINVAL);
2767	}
2768	disk = g_mirror_init_disk(sc, pp, md, &error);
2769	if (disk == NULL)
2770		return (error);
2771	error = g_mirror_event_send(disk, G_MIRROR_DISK_STATE_NEW,
2772	    G_MIRROR_EVENT_WAIT);
2773	if (error != 0)
2774		return (error);
2775	if (md->md_version < G_MIRROR_VERSION) {
2776		G_MIRROR_DEBUG(0, "Upgrading metadata on %s (v%d->v%d).",
2777		    pp->name, md->md_version, G_MIRROR_VERSION);
2778		g_mirror_update_metadata(disk);
2779	}
2780	return (0);
2781}
2782
2783static void
2784g_mirror_destroy_delayed(void *arg, int flag)
2785{
2786	struct g_mirror_softc *sc;
2787	int error;
2788
2789	if (flag == EV_CANCEL) {
2790		G_MIRROR_DEBUG(1, "Destroying canceled.");
2791		return;
2792	}
2793	sc = arg;
2794	g_topology_unlock();
2795	sx_xlock(&sc->sc_lock);
2796	KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) == 0,
2797	    ("DESTROY flag set on %s.", sc->sc_name));
2798	KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROYING) != 0,
2799	    ("DESTROYING flag not set on %s.", sc->sc_name));
2800	G_MIRROR_DEBUG(1, "Destroying %s (delayed).", sc->sc_name);
2801	error = g_mirror_destroy(sc, G_MIRROR_DESTROY_SOFT);
2802	if (error != 0) {
2803		G_MIRROR_DEBUG(0, "Cannot destroy %s.", sc->sc_name);
2804		sx_xunlock(&sc->sc_lock);
2805	}
2806	g_topology_lock();
2807}
2808
2809static int
2810g_mirror_access(struct g_provider *pp, int acr, int acw, int ace)
2811{
2812	struct g_mirror_softc *sc;
2813	int dcr, dcw, dce, error = 0;
2814
2815	g_topology_assert();
2816	G_MIRROR_DEBUG(2, "Access request for %s: r%dw%de%d.", pp->name, acr,
2817	    acw, ace);
2818
2819	sc = pp->geom->softc;
2820	if (sc == NULL && acr <= 0 && acw <= 0 && ace <= 0)
2821		return (0);
2822	KASSERT(sc != NULL, ("NULL softc (provider=%s).", pp->name));
2823
2824	dcr = pp->acr + acr;
2825	dcw = pp->acw + acw;
2826	dce = pp->ace + ace;
2827
2828	g_topology_unlock();
2829	sx_xlock(&sc->sc_lock);
2830	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0 ||
2831	    LIST_EMPTY(&sc->sc_disks)) {
2832		if (acr > 0 || acw > 0 || ace > 0)
2833			error = ENXIO;
2834		goto end;
2835	}
2836	if (dcw == 0)
2837		g_mirror_idle(sc, dcw);
2838	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROYING) != 0) {
2839		if (acr > 0 || acw > 0 || ace > 0) {
2840			error = ENXIO;
2841			goto end;
2842		}
2843		if (dcr == 0 && dcw == 0 && dce == 0) {
2844			g_post_event(g_mirror_destroy_delayed, sc, M_WAITOK,
2845			    sc, NULL);
2846		}
2847	}
2848end:
2849	sx_xunlock(&sc->sc_lock);
2850	g_topology_lock();
2851	return (error);
2852}
2853
2854static struct g_geom *
2855g_mirror_create(struct g_class *mp, const struct g_mirror_metadata *md)
2856{
2857	struct g_mirror_softc *sc;
2858	struct g_geom *gp;
2859	int error, timeout;
2860
2861	g_topology_assert();
2862	G_MIRROR_DEBUG(1, "Creating device %s (id=%u).", md->md_name,
2863	    md->md_mid);
2864
2865	/* One disk is minimum. */
2866	if (md->md_all < 1)
2867		return (NULL);
2868	/*
2869	 * Action geom.
2870	 */
2871	gp = g_new_geomf(mp, "%s", md->md_name);
2872	sc = malloc(sizeof(*sc), M_MIRROR, M_WAITOK | M_ZERO);
2873	gp->start = g_mirror_start;
2874	gp->orphan = g_mirror_orphan;
2875	gp->access = g_mirror_access;
2876	gp->dumpconf = g_mirror_dumpconf;
2877
2878	sc->sc_id = md->md_mid;
2879	sc->sc_slice = md->md_slice;
2880	sc->sc_balance = md->md_balance;
2881	sc->sc_mediasize = md->md_mediasize;
2882	sc->sc_sectorsize = md->md_sectorsize;
2883	sc->sc_ndisks = md->md_all;
2884	sc->sc_flags = md->md_mflags;
2885	sc->sc_bump_id = 0;
2886	sc->sc_idle = 1;
2887	sc->sc_last_write = time_uptime;
2888	sc->sc_writes = 0;
2889	sx_init(&sc->sc_lock, "gmirror:lock");
2890	bioq_init(&sc->sc_queue);
2891	mtx_init(&sc->sc_queue_mtx, "gmirror:queue", NULL, MTX_DEF);
2892	bioq_init(&sc->sc_regular_delayed);
2893	bioq_init(&sc->sc_inflight);
2894	bioq_init(&sc->sc_sync_delayed);
2895	LIST_INIT(&sc->sc_disks);
2896	TAILQ_INIT(&sc->sc_events);
2897	mtx_init(&sc->sc_events_mtx, "gmirror:events", NULL, MTX_DEF);
2898	callout_init(&sc->sc_callout, CALLOUT_MPSAFE);
2899	sc->sc_state = G_MIRROR_DEVICE_STATE_STARTING;
2900	gp->softc = sc;
2901	sc->sc_geom = gp;
2902	sc->sc_provider = NULL;
2903	/*
2904	 * Synchronization geom.
2905	 */
2906	gp = g_new_geomf(mp, "%s.sync", md->md_name);
2907	gp->softc = sc;
2908	gp->orphan = g_mirror_orphan;
2909	sc->sc_sync.ds_geom = gp;
2910	sc->sc_sync.ds_ndisks = 0;
2911	error = kproc_create(g_mirror_worker, sc, &sc->sc_worker, 0, 0,
2912	    "g_mirror %s", md->md_name);
2913	if (error != 0) {
2914		G_MIRROR_DEBUG(1, "Cannot create kernel thread for %s.",
2915		    sc->sc_name);
2916		g_destroy_geom(sc->sc_sync.ds_geom);
2917		mtx_destroy(&sc->sc_events_mtx);
2918		mtx_destroy(&sc->sc_queue_mtx);
2919		sx_destroy(&sc->sc_lock);
2920		g_destroy_geom(sc->sc_geom);
2921		free(sc, M_MIRROR);
2922		return (NULL);
2923	}
2924
2925	G_MIRROR_DEBUG(1, "Device %s created (%u components, id=%u).",
2926	    sc->sc_name, sc->sc_ndisks, sc->sc_id);
2927
2928	sc->sc_rootmount = root_mount_hold("GMIRROR");
2929	G_MIRROR_DEBUG(1, "root_mount_hold %p", sc->sc_rootmount);
2930	/*
2931	 * Run timeout.
2932	 */
2933	timeout = g_mirror_timeout * hz;
2934	callout_reset(&sc->sc_callout, timeout, g_mirror_go, sc);
2935	return (sc->sc_geom);
2936}
2937
2938int
2939g_mirror_destroy(struct g_mirror_softc *sc, int how)
2940{
2941	struct g_mirror_disk *disk;
2942	struct g_provider *pp;
2943
2944	g_topology_assert_not();
2945	if (sc == NULL)
2946		return (ENXIO);
2947	sx_assert(&sc->sc_lock, SX_XLOCKED);
2948
2949	pp = sc->sc_provider;
2950	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
2951		switch (how) {
2952		case G_MIRROR_DESTROY_SOFT:
2953			G_MIRROR_DEBUG(1,
2954			    "Device %s is still open (r%dw%de%d).", pp->name,
2955			    pp->acr, pp->acw, pp->ace);
2956			return (EBUSY);
2957		case G_MIRROR_DESTROY_DELAYED:
2958			G_MIRROR_DEBUG(1,
2959			    "Device %s will be destroyed on last close.",
2960			    pp->name);
2961			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2962				if (disk->d_state ==
2963				    G_MIRROR_DISK_STATE_SYNCHRONIZING) {
2964					g_mirror_sync_stop(disk, 1);
2965				}
2966			}
2967			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROYING;
2968			return (EBUSY);
2969		case G_MIRROR_DESTROY_HARD:
2970			G_MIRROR_DEBUG(1, "Device %s is still open, so it "
2971			    "can't be definitely removed.", pp->name);
2972		}
2973	}
2974
2975	g_topology_lock();
2976	if (sc->sc_geom->softc == NULL) {
2977		g_topology_unlock();
2978		return (0);
2979	}
2980	sc->sc_geom->softc = NULL;
2981	sc->sc_sync.ds_geom->softc = NULL;
2982	g_topology_unlock();
2983
2984	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2985	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_WAIT;
2986	G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
2987	sx_xunlock(&sc->sc_lock);
2988	mtx_lock(&sc->sc_queue_mtx);
2989	wakeup(sc);
2990	mtx_unlock(&sc->sc_queue_mtx);
2991	G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, &sc->sc_worker);
2992	while (sc->sc_worker != NULL)
2993		tsleep(&sc->sc_worker, PRIBIO, "m:destroy", hz / 5);
2994	G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, &sc->sc_worker);
2995	sx_xlock(&sc->sc_lock);
2996	g_mirror_destroy_device(sc);
2997	free(sc, M_MIRROR);
2998	return (0);
2999}
3000
3001static void
3002g_mirror_taste_orphan(struct g_consumer *cp)
3003{
3004
3005	KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
3006	    cp->provider->name));
3007}
3008
3009static struct g_geom *
3010g_mirror_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
3011{
3012	struct g_mirror_metadata md;
3013	struct g_mirror_softc *sc;
3014	struct g_consumer *cp;
3015	struct g_geom *gp;
3016	int error;
3017
3018	g_topology_assert();
3019	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
3020	G_MIRROR_DEBUG(2, "Tasting %s.", pp->name);
3021
3022	gp = g_new_geomf(mp, "mirror:taste");
3023	/*
3024	 * This orphan function should be never called.
3025	 */
3026	gp->orphan = g_mirror_taste_orphan;
3027	cp = g_new_consumer(gp);
3028	g_attach(cp, pp);
3029	error = g_mirror_read_metadata(cp, &md);
3030	g_detach(cp);
3031	g_destroy_consumer(cp);
3032	g_destroy_geom(gp);
3033	if (error != 0)
3034		return (NULL);
3035	gp = NULL;
3036
3037	if (md.md_provider[0] != '\0' &&
3038	    !g_compare_names(md.md_provider, pp->name))
3039		return (NULL);
3040	if (md.md_provsize != 0 && md.md_provsize != pp->mediasize)
3041		return (NULL);
3042	if ((md.md_dflags & G_MIRROR_DISK_FLAG_INACTIVE) != 0) {
3043		G_MIRROR_DEBUG(0,
3044		    "Device %s: provider %s marked as inactive, skipping.",
3045		    md.md_name, pp->name);
3046		return (NULL);
3047	}
3048	if (g_mirror_debug >= 2)
3049		mirror_metadata_dump(&md);
3050
3051	/*
3052	 * Let's check if device already exists.
3053	 */
3054	sc = NULL;
3055	LIST_FOREACH(gp, &mp->geom, geom) {
3056		sc = gp->softc;
3057		if (sc == NULL)
3058			continue;
3059		if (sc->sc_sync.ds_geom == gp)
3060			continue;
3061		if (strcmp(md.md_name, sc->sc_name) != 0)
3062			continue;
3063		if (md.md_mid != sc->sc_id) {
3064			G_MIRROR_DEBUG(0, "Device %s already configured.",
3065			    sc->sc_name);
3066			return (NULL);
3067		}
3068		break;
3069	}
3070	if (gp == NULL) {
3071		gp = g_mirror_create(mp, &md);
3072		if (gp == NULL) {
3073			G_MIRROR_DEBUG(0, "Cannot create device %s.",
3074			    md.md_name);
3075			return (NULL);
3076		}
3077		sc = gp->softc;
3078	}
3079	G_MIRROR_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
3080	g_topology_unlock();
3081	sx_xlock(&sc->sc_lock);
3082	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_TASTING;
3083	error = g_mirror_add_disk(sc, pp, &md);
3084	if (error != 0) {
3085		G_MIRROR_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
3086		    pp->name, gp->name, error);
3087		if (LIST_EMPTY(&sc->sc_disks)) {
3088			g_cancel_event(sc);
3089			g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
3090			g_topology_lock();
3091			return (NULL);
3092		}
3093		gp = NULL;
3094	}
3095	sc->sc_flags &= ~G_MIRROR_DEVICE_FLAG_TASTING;
3096	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
3097		g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
3098		g_topology_lock();
3099		return (NULL);
3100	}
3101	sx_xunlock(&sc->sc_lock);
3102	g_topology_lock();
3103	return (gp);
3104}
3105
3106static int
3107g_mirror_destroy_geom(struct gctl_req *req __unused,
3108    struct g_class *mp __unused, struct g_geom *gp)
3109{
3110	struct g_mirror_softc *sc;
3111	int error;
3112
3113	g_topology_unlock();
3114	sc = gp->softc;
3115	sx_xlock(&sc->sc_lock);
3116	g_cancel_event(sc);
3117	error = g_mirror_destroy(gp->softc, G_MIRROR_DESTROY_SOFT);
3118	if (error != 0)
3119		sx_xunlock(&sc->sc_lock);
3120	g_topology_lock();
3121	return (error);
3122}
3123
3124static void
3125g_mirror_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
3126    struct g_consumer *cp, struct g_provider *pp)
3127{
3128	struct g_mirror_softc *sc;
3129
3130	g_topology_assert();
3131
3132	sc = gp->softc;
3133	if (sc == NULL)
3134		return;
3135	/* Skip synchronization geom. */
3136	if (gp == sc->sc_sync.ds_geom)
3137		return;
3138	if (pp != NULL) {
3139		/* Nothing here. */
3140	} else if (cp != NULL) {
3141		struct g_mirror_disk *disk;
3142
3143		disk = cp->private;
3144		if (disk == NULL)
3145			return;
3146		g_topology_unlock();
3147		sx_xlock(&sc->sc_lock);
3148		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)disk->d_id);
3149		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
3150			sbuf_printf(sb, "%s<Synchronized>", indent);
3151			if (disk->d_sync.ds_offset == 0)
3152				sbuf_printf(sb, "0%%");
3153			else {
3154				sbuf_printf(sb, "%u%%",
3155				    (u_int)((disk->d_sync.ds_offset * 100) /
3156				    sc->sc_provider->mediasize));
3157			}
3158			sbuf_printf(sb, "</Synchronized>\n");
3159			if (disk->d_sync.ds_offset > 0) {
3160				sbuf_printf(sb, "%s<BytesSynced>%jd"
3161				    "</BytesSynced>\n", indent,
3162				    (intmax_t)disk->d_sync.ds_offset);
3163			}
3164		}
3165		sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent,
3166		    disk->d_sync.ds_syncid);
3167		sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent,
3168		    disk->d_genid);
3169		sbuf_printf(sb, "%s<Flags>", indent);
3170		if (disk->d_flags == 0)
3171			sbuf_printf(sb, "NONE");
3172		else {
3173			int first = 1;
3174
3175#define	ADD_FLAG(flag, name)	do {					\
3176	if ((disk->d_flags & (flag)) != 0) {				\
3177		if (!first)						\
3178			sbuf_printf(sb, ", ");				\
3179		else							\
3180			first = 0;					\
3181		sbuf_printf(sb, name);					\
3182	}								\
3183} while (0)
3184			ADD_FLAG(G_MIRROR_DISK_FLAG_DIRTY, "DIRTY");
3185			ADD_FLAG(G_MIRROR_DISK_FLAG_HARDCODED, "HARDCODED");
3186			ADD_FLAG(G_MIRROR_DISK_FLAG_INACTIVE, "INACTIVE");
3187			ADD_FLAG(G_MIRROR_DISK_FLAG_SYNCHRONIZING,
3188			    "SYNCHRONIZING");
3189			ADD_FLAG(G_MIRROR_DISK_FLAG_FORCE_SYNC, "FORCE_SYNC");
3190			ADD_FLAG(G_MIRROR_DISK_FLAG_BROKEN, "BROKEN");
3191#undef	ADD_FLAG
3192		}
3193		sbuf_printf(sb, "</Flags>\n");
3194		sbuf_printf(sb, "%s<Priority>%u</Priority>\n", indent,
3195		    disk->d_priority);
3196		sbuf_printf(sb, "%s<State>%s</State>\n", indent,
3197		    g_mirror_disk_state2str(disk->d_state));
3198		sx_xunlock(&sc->sc_lock);
3199		g_topology_lock();
3200	} else {
3201		g_topology_unlock();
3202		sx_xlock(&sc->sc_lock);
3203		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
3204		sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent, sc->sc_syncid);
3205		sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent, sc->sc_genid);
3206		sbuf_printf(sb, "%s<Flags>", indent);
3207		if (sc->sc_flags == 0)
3208			sbuf_printf(sb, "NONE");
3209		else {
3210			int first = 1;
3211
3212#define	ADD_FLAG(flag, name)	do {					\
3213	if ((sc->sc_flags & (flag)) != 0) {				\
3214		if (!first)						\
3215			sbuf_printf(sb, ", ");				\
3216		else							\
3217			first = 0;					\
3218		sbuf_printf(sb, name);					\
3219	}								\
3220} while (0)
3221			ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOFAILSYNC, "NOFAILSYNC");
3222			ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOAUTOSYNC, "NOAUTOSYNC");
3223#undef	ADD_FLAG
3224		}
3225		sbuf_printf(sb, "</Flags>\n");
3226		sbuf_printf(sb, "%s<Slice>%u</Slice>\n", indent,
3227		    (u_int)sc->sc_slice);
3228		sbuf_printf(sb, "%s<Balance>%s</Balance>\n", indent,
3229		    balance_name(sc->sc_balance));
3230		sbuf_printf(sb, "%s<Components>%u</Components>\n", indent,
3231		    sc->sc_ndisks);
3232		sbuf_printf(sb, "%s<State>", indent);
3233		if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
3234			sbuf_printf(sb, "%s", "STARTING");
3235		else if (sc->sc_ndisks ==
3236		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE))
3237			sbuf_printf(sb, "%s", "COMPLETE");
3238		else
3239			sbuf_printf(sb, "%s", "DEGRADED");
3240		sbuf_printf(sb, "</State>\n");
3241		sx_xunlock(&sc->sc_lock);
3242		g_topology_lock();
3243	}
3244}
3245
3246static void
3247g_mirror_shutdown_post_sync(void *arg, int howto)
3248{
3249	struct g_class *mp;
3250	struct g_geom *gp, *gp2;
3251	struct g_mirror_softc *sc;
3252	int error;
3253
3254	mp = arg;
3255	DROP_GIANT();
3256	g_topology_lock();
3257	g_mirror_shutdown = 1;
3258	LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
3259		if ((sc = gp->softc) == NULL)
3260			continue;
3261		/* Skip synchronization geom. */
3262		if (gp == sc->sc_sync.ds_geom)
3263			continue;
3264		g_topology_unlock();
3265		sx_xlock(&sc->sc_lock);
3266		g_mirror_idle(sc, -1);
3267		g_cancel_event(sc);
3268		error = g_mirror_destroy(sc, G_MIRROR_DESTROY_DELAYED);
3269		if (error != 0)
3270			sx_xunlock(&sc->sc_lock);
3271		g_topology_lock();
3272	}
3273	g_topology_unlock();
3274	PICKUP_GIANT();
3275}
3276
3277static void
3278g_mirror_init(struct g_class *mp)
3279{
3280
3281	g_mirror_post_sync = EVENTHANDLER_REGISTER(shutdown_post_sync,
3282	    g_mirror_shutdown_post_sync, mp, SHUTDOWN_PRI_FIRST);
3283	if (g_mirror_post_sync == NULL)
3284		G_MIRROR_DEBUG(0, "Warning! Cannot register shutdown event.");
3285}
3286
3287static void
3288g_mirror_fini(struct g_class *mp)
3289{
3290
3291	if (g_mirror_post_sync != NULL)
3292		EVENTHANDLER_DEREGISTER(shutdown_post_sync, g_mirror_post_sync);
3293}
3294
3295DECLARE_GEOM_CLASS(g_mirror_class, g_mirror);
3296