g_mirror.c revision 245946
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 245946 2013-01-26 10:50:04Z avg $");
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;
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	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2042		if (disk->d_consumer && disk->d_consumer->provider &&
2043		    disk->d_consumer->provider->stripesize > pp->stripesize) {
2044			pp->stripesize = disk->d_consumer->provider->stripesize;
2045			pp->stripeoffset = disk->d_consumer->provider->stripeoffset;
2046		}
2047	}
2048	sc->sc_provider = pp;
2049	g_error_provider(pp, 0);
2050	g_topology_unlock();
2051	G_MIRROR_DEBUG(0, "Device %s launched (%u/%u).", pp->name,
2052	    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE), sc->sc_ndisks);
2053	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2054		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2055			g_mirror_sync_start(disk);
2056	}
2057}
2058
2059static void
2060g_mirror_destroy_provider(struct g_mirror_softc *sc)
2061{
2062	struct g_mirror_disk *disk;
2063	struct bio *bp;
2064
2065	g_topology_assert_not();
2066	KASSERT(sc->sc_provider != NULL, ("NULL provider (device=%s).",
2067	    sc->sc_name));
2068
2069	g_topology_lock();
2070	g_error_provider(sc->sc_provider, ENXIO);
2071	mtx_lock(&sc->sc_queue_mtx);
2072	while ((bp = bioq_first(&sc->sc_queue)) != NULL) {
2073		bioq_remove(&sc->sc_queue, bp);
2074		g_io_deliver(bp, ENXIO);
2075	}
2076	mtx_unlock(&sc->sc_queue_mtx);
2077	G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.", sc->sc_name,
2078	    sc->sc_provider->name);
2079	sc->sc_provider->flags |= G_PF_WITHER;
2080	g_orphan_provider(sc->sc_provider, ENXIO);
2081	g_topology_unlock();
2082	sc->sc_provider = NULL;
2083	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2084		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2085			g_mirror_sync_stop(disk, 1);
2086	}
2087}
2088
2089static void
2090g_mirror_go(void *arg)
2091{
2092	struct g_mirror_softc *sc;
2093
2094	sc = arg;
2095	G_MIRROR_DEBUG(0, "Force device %s start due to timeout.", sc->sc_name);
2096	g_mirror_event_send(sc, 0,
2097	    G_MIRROR_EVENT_DONTWAIT | G_MIRROR_EVENT_DEVICE);
2098}
2099
2100static u_int
2101g_mirror_determine_state(struct g_mirror_disk *disk)
2102{
2103	struct g_mirror_softc *sc;
2104	u_int state;
2105
2106	sc = disk->d_softc;
2107	if (sc->sc_syncid == disk->d_sync.ds_syncid) {
2108		if ((disk->d_flags &
2109		    G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2110			/* Disk does not need synchronization. */
2111			state = G_MIRROR_DISK_STATE_ACTIVE;
2112		} else {
2113			if ((sc->sc_flags &
2114			     G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2115			    (disk->d_flags &
2116			     G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2117				/*
2118				 * We can start synchronization from
2119				 * the stored offset.
2120				 */
2121				state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2122			} else {
2123				state = G_MIRROR_DISK_STATE_STALE;
2124			}
2125		}
2126	} else if (disk->d_sync.ds_syncid < sc->sc_syncid) {
2127		/*
2128		 * Reset all synchronization data for this disk,
2129		 * because if it even was synchronized, it was
2130		 * synchronized to disks with different syncid.
2131		 */
2132		disk->d_flags |= G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2133		disk->d_sync.ds_offset = 0;
2134		disk->d_sync.ds_offset_done = 0;
2135		disk->d_sync.ds_syncid = sc->sc_syncid;
2136		if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2137		    (disk->d_flags & G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2138			state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2139		} else {
2140			state = G_MIRROR_DISK_STATE_STALE;
2141		}
2142	} else /* if (sc->sc_syncid < disk->d_sync.ds_syncid) */ {
2143		/*
2144		 * Not good, NOT GOOD!
2145		 * It means that mirror was started on stale disks
2146		 * and more fresh disk just arrive.
2147		 * If there were writes, mirror is broken, sorry.
2148		 * I think the best choice here is don't touch
2149		 * this disk and inform the user loudly.
2150		 */
2151		G_MIRROR_DEBUG(0, "Device %s was started before the freshest "
2152		    "disk (%s) arrives!! It will not be connected to the "
2153		    "running device.", sc->sc_name,
2154		    g_mirror_get_diskname(disk));
2155		g_mirror_destroy_disk(disk);
2156		state = G_MIRROR_DISK_STATE_NONE;
2157		/* Return immediately, because disk was destroyed. */
2158		return (state);
2159	}
2160	G_MIRROR_DEBUG(3, "State for %s disk: %s.",
2161	    g_mirror_get_diskname(disk), g_mirror_disk_state2str(state));
2162	return (state);
2163}
2164
2165/*
2166 * Update device state.
2167 */
2168static void
2169g_mirror_update_device(struct g_mirror_softc *sc, boolean_t force)
2170{
2171	struct g_mirror_disk *disk;
2172	u_int state;
2173
2174	sx_assert(&sc->sc_lock, SX_XLOCKED);
2175
2176	switch (sc->sc_state) {
2177	case G_MIRROR_DEVICE_STATE_STARTING:
2178	    {
2179		struct g_mirror_disk *pdisk, *tdisk;
2180		u_int dirty, ndisks, genid, syncid;
2181
2182		KASSERT(sc->sc_provider == NULL,
2183		    ("Non-NULL provider in STARTING state (%s).", sc->sc_name));
2184		/*
2185		 * Are we ready? We are, if all disks are connected or
2186		 * if we have any disks and 'force' is true.
2187		 */
2188		ndisks = g_mirror_ndisks(sc, -1);
2189		if (sc->sc_ndisks == ndisks || (force && ndisks > 0)) {
2190			;
2191		} else if (ndisks == 0) {
2192			/*
2193			 * Disks went down in starting phase, so destroy
2194			 * device.
2195			 */
2196			callout_drain(&sc->sc_callout);
2197			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2198			G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
2199			    sc->sc_rootmount);
2200			root_mount_rel(sc->sc_rootmount);
2201			sc->sc_rootmount = NULL;
2202			return;
2203		} else {
2204			return;
2205		}
2206
2207		/*
2208		 * Activate all disks with the biggest syncid.
2209		 */
2210		if (force) {
2211			/*
2212			 * If 'force' is true, we have been called due to
2213			 * timeout, so don't bother canceling timeout.
2214			 */
2215			ndisks = 0;
2216			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2217				if ((disk->d_flags &
2218				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2219					ndisks++;
2220				}
2221			}
2222			if (ndisks == 0) {
2223				/* No valid disks found, destroy device. */
2224				sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2225				G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2226				    __LINE__, sc->sc_rootmount);
2227				root_mount_rel(sc->sc_rootmount);
2228				sc->sc_rootmount = NULL;
2229				return;
2230			}
2231		} else {
2232			/* Cancel timeout. */
2233			callout_drain(&sc->sc_callout);
2234		}
2235
2236		/*
2237		 * Find the biggest genid.
2238		 */
2239		genid = 0;
2240		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2241			if (disk->d_genid > genid)
2242				genid = disk->d_genid;
2243		}
2244		sc->sc_genid = genid;
2245		/*
2246		 * Remove all disks without the biggest genid.
2247		 */
2248		LIST_FOREACH_SAFE(disk, &sc->sc_disks, d_next, tdisk) {
2249			if (disk->d_genid < genid) {
2250				G_MIRROR_DEBUG(0,
2251				    "Component %s (device %s) broken, skipping.",
2252				    g_mirror_get_diskname(disk), sc->sc_name);
2253				g_mirror_destroy_disk(disk);
2254			}
2255		}
2256
2257		/*
2258		 * Find the biggest syncid.
2259		 */
2260		syncid = 0;
2261		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2262			if (disk->d_sync.ds_syncid > syncid)
2263				syncid = disk->d_sync.ds_syncid;
2264		}
2265
2266		/*
2267		 * Here we need to look for dirty disks and if all disks
2268		 * with the biggest syncid are dirty, we have to choose
2269		 * one with the biggest priority and rebuild the rest.
2270		 */
2271		/*
2272		 * Find the number of dirty disks with the biggest syncid.
2273		 * Find the number of disks with the biggest syncid.
2274		 * While here, find a disk with the biggest priority.
2275		 */
2276		dirty = ndisks = 0;
2277		pdisk = NULL;
2278		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2279			if (disk->d_sync.ds_syncid != syncid)
2280				continue;
2281			if ((disk->d_flags &
2282			    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2283				continue;
2284			}
2285			ndisks++;
2286			if ((disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
2287				dirty++;
2288				if (pdisk == NULL ||
2289				    pdisk->d_priority < disk->d_priority) {
2290					pdisk = disk;
2291				}
2292			}
2293		}
2294		if (dirty == 0) {
2295			/* No dirty disks at all, great. */
2296		} else if (dirty == ndisks) {
2297			/*
2298			 * Force synchronization for all dirty disks except one
2299			 * with the biggest priority.
2300			 */
2301			KASSERT(pdisk != NULL, ("pdisk == NULL"));
2302			G_MIRROR_DEBUG(1, "Using disk %s (device %s) as a "
2303			    "master disk for synchronization.",
2304			    g_mirror_get_diskname(pdisk), sc->sc_name);
2305			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2306				if (disk->d_sync.ds_syncid != syncid)
2307					continue;
2308				if ((disk->d_flags &
2309				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2310					continue;
2311				}
2312				KASSERT((disk->d_flags &
2313				    G_MIRROR_DISK_FLAG_DIRTY) != 0,
2314				    ("Disk %s isn't marked as dirty.",
2315				    g_mirror_get_diskname(disk)));
2316				/* Skip the disk with the biggest priority. */
2317				if (disk == pdisk)
2318					continue;
2319				disk->d_sync.ds_syncid = 0;
2320			}
2321		} else if (dirty < ndisks) {
2322			/*
2323			 * Force synchronization for all dirty disks.
2324			 * We have some non-dirty disks.
2325			 */
2326			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2327				if (disk->d_sync.ds_syncid != syncid)
2328					continue;
2329				if ((disk->d_flags &
2330				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2331					continue;
2332				}
2333				if ((disk->d_flags &
2334				    G_MIRROR_DISK_FLAG_DIRTY) == 0) {
2335					continue;
2336				}
2337				disk->d_sync.ds_syncid = 0;
2338			}
2339		}
2340
2341		/* Reset hint. */
2342		sc->sc_hint = NULL;
2343		sc->sc_syncid = syncid;
2344		if (force) {
2345			/* Remember to bump syncid on first write. */
2346			sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2347		}
2348		state = G_MIRROR_DEVICE_STATE_RUNNING;
2349		G_MIRROR_DEBUG(1, "Device %s state changed from %s to %s.",
2350		    sc->sc_name, g_mirror_device_state2str(sc->sc_state),
2351		    g_mirror_device_state2str(state));
2352		sc->sc_state = state;
2353		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2354			state = g_mirror_determine_state(disk);
2355			g_mirror_event_send(disk, state,
2356			    G_MIRROR_EVENT_DONTWAIT);
2357			if (state == G_MIRROR_DISK_STATE_STALE)
2358				sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2359		}
2360		break;
2361	    }
2362	case G_MIRROR_DEVICE_STATE_RUNNING:
2363		if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 0 &&
2364		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2365			/*
2366			 * No active disks or no disks at all,
2367			 * so destroy device.
2368			 */
2369			if (sc->sc_provider != NULL)
2370				g_mirror_destroy_provider(sc);
2371			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2372			break;
2373		} else if (g_mirror_ndisks(sc,
2374		    G_MIRROR_DISK_STATE_ACTIVE) > 0 &&
2375		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2376			/*
2377			 * We have active disks, launch provider if it doesn't
2378			 * exist.
2379			 */
2380			if (sc->sc_provider == NULL)
2381				g_mirror_launch_provider(sc);
2382			if (sc->sc_rootmount != NULL) {
2383				G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2384				    __LINE__, sc->sc_rootmount);
2385				root_mount_rel(sc->sc_rootmount);
2386				sc->sc_rootmount = NULL;
2387			}
2388		}
2389		/*
2390		 * Genid should be bumped immediately, so do it here.
2391		 */
2392		if ((sc->sc_bump_id & G_MIRROR_BUMP_GENID) != 0) {
2393			sc->sc_bump_id &= ~G_MIRROR_BUMP_GENID;
2394			g_mirror_bump_genid(sc);
2395		}
2396		break;
2397	default:
2398		KASSERT(1 == 0, ("Wrong device state (%s, %s).",
2399		    sc->sc_name, g_mirror_device_state2str(sc->sc_state)));
2400		break;
2401	}
2402}
2403
2404/*
2405 * Update disk state and device state if needed.
2406 */
2407#define	DISK_STATE_CHANGED()	G_MIRROR_DEBUG(1,			\
2408	"Disk %s state changed from %s to %s (device %s).",		\
2409	g_mirror_get_diskname(disk),					\
2410	g_mirror_disk_state2str(disk->d_state),				\
2411	g_mirror_disk_state2str(state), sc->sc_name)
2412static int
2413g_mirror_update_disk(struct g_mirror_disk *disk, u_int state)
2414{
2415	struct g_mirror_softc *sc;
2416
2417	sc = disk->d_softc;
2418	sx_assert(&sc->sc_lock, SX_XLOCKED);
2419
2420again:
2421	G_MIRROR_DEBUG(3, "Changing disk %s state from %s to %s.",
2422	    g_mirror_get_diskname(disk), g_mirror_disk_state2str(disk->d_state),
2423	    g_mirror_disk_state2str(state));
2424	switch (state) {
2425	case G_MIRROR_DISK_STATE_NEW:
2426		/*
2427		 * Possible scenarios:
2428		 * 1. New disk arrive.
2429		 */
2430		/* Previous state should be NONE. */
2431		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NONE,
2432		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2433		    g_mirror_disk_state2str(disk->d_state)));
2434		DISK_STATE_CHANGED();
2435
2436		disk->d_state = state;
2437		if (LIST_EMPTY(&sc->sc_disks))
2438			LIST_INSERT_HEAD(&sc->sc_disks, disk, d_next);
2439		else {
2440			struct g_mirror_disk *dp;
2441
2442			LIST_FOREACH(dp, &sc->sc_disks, d_next) {
2443				if (disk->d_priority >= dp->d_priority) {
2444					LIST_INSERT_BEFORE(dp, disk, d_next);
2445					dp = NULL;
2446					break;
2447				}
2448				if (LIST_NEXT(dp, d_next) == NULL)
2449					break;
2450			}
2451			if (dp != NULL)
2452				LIST_INSERT_AFTER(dp, disk, d_next);
2453		}
2454		G_MIRROR_DEBUG(1, "Device %s: provider %s detected.",
2455		    sc->sc_name, g_mirror_get_diskname(disk));
2456		if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
2457			break;
2458		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2459		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2460		    g_mirror_device_state2str(sc->sc_state),
2461		    g_mirror_get_diskname(disk),
2462		    g_mirror_disk_state2str(disk->d_state)));
2463		state = g_mirror_determine_state(disk);
2464		if (state != G_MIRROR_DISK_STATE_NONE)
2465			goto again;
2466		break;
2467	case G_MIRROR_DISK_STATE_ACTIVE:
2468		/*
2469		 * Possible scenarios:
2470		 * 1. New disk does not need synchronization.
2471		 * 2. Synchronization process finished successfully.
2472		 */
2473		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2474		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2475		    g_mirror_device_state2str(sc->sc_state),
2476		    g_mirror_get_diskname(disk),
2477		    g_mirror_disk_state2str(disk->d_state)));
2478		/* Previous state should be NEW or SYNCHRONIZING. */
2479		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW ||
2480		    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2481		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2482		    g_mirror_disk_state2str(disk->d_state)));
2483		DISK_STATE_CHANGED();
2484
2485		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
2486			disk->d_flags &= ~G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2487			disk->d_flags &= ~G_MIRROR_DISK_FLAG_FORCE_SYNC;
2488			g_mirror_sync_stop(disk, 0);
2489		}
2490		disk->d_state = state;
2491		disk->d_sync.ds_offset = 0;
2492		disk->d_sync.ds_offset_done = 0;
2493		g_mirror_update_idle(sc, disk);
2494		g_mirror_update_metadata(disk);
2495		G_MIRROR_DEBUG(1, "Device %s: provider %s activated.",
2496		    sc->sc_name, g_mirror_get_diskname(disk));
2497		break;
2498	case G_MIRROR_DISK_STATE_STALE:
2499		/*
2500		 * Possible scenarios:
2501		 * 1. Stale disk was connected.
2502		 */
2503		/* Previous state should be NEW. */
2504		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2505		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2506		    g_mirror_disk_state2str(disk->d_state)));
2507		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2508		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2509		    g_mirror_device_state2str(sc->sc_state),
2510		    g_mirror_get_diskname(disk),
2511		    g_mirror_disk_state2str(disk->d_state)));
2512		/*
2513		 * STALE state is only possible if device is marked
2514		 * NOAUTOSYNC.
2515		 */
2516		KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0,
2517		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2518		    g_mirror_device_state2str(sc->sc_state),
2519		    g_mirror_get_diskname(disk),
2520		    g_mirror_disk_state2str(disk->d_state)));
2521		DISK_STATE_CHANGED();
2522
2523		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2524		disk->d_state = state;
2525		g_mirror_update_metadata(disk);
2526		G_MIRROR_DEBUG(0, "Device %s: provider %s is stale.",
2527		    sc->sc_name, g_mirror_get_diskname(disk));
2528		break;
2529	case G_MIRROR_DISK_STATE_SYNCHRONIZING:
2530		/*
2531		 * Possible scenarios:
2532		 * 1. Disk which needs synchronization was connected.
2533		 */
2534		/* Previous state should be NEW. */
2535		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2536		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2537		    g_mirror_disk_state2str(disk->d_state)));
2538		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2539		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2540		    g_mirror_device_state2str(sc->sc_state),
2541		    g_mirror_get_diskname(disk),
2542		    g_mirror_disk_state2str(disk->d_state)));
2543		DISK_STATE_CHANGED();
2544
2545		if (disk->d_state == G_MIRROR_DISK_STATE_NEW)
2546			disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2547		disk->d_state = state;
2548		if (sc->sc_provider != NULL) {
2549			g_mirror_sync_start(disk);
2550			g_mirror_update_metadata(disk);
2551		}
2552		break;
2553	case G_MIRROR_DISK_STATE_DISCONNECTED:
2554		/*
2555		 * Possible scenarios:
2556		 * 1. Device wasn't running yet, but disk disappear.
2557		 * 2. Disk was active and disapppear.
2558		 * 3. Disk disappear during synchronization process.
2559		 */
2560		if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING) {
2561			/*
2562			 * Previous state should be ACTIVE, STALE or
2563			 * SYNCHRONIZING.
2564			 */
2565			KASSERT(disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
2566			    disk->d_state == G_MIRROR_DISK_STATE_STALE ||
2567			    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2568			    ("Wrong disk state (%s, %s).",
2569			    g_mirror_get_diskname(disk),
2570			    g_mirror_disk_state2str(disk->d_state)));
2571		} else if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING) {
2572			/* Previous state should be NEW. */
2573			KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2574			    ("Wrong disk state (%s, %s).",
2575			    g_mirror_get_diskname(disk),
2576			    g_mirror_disk_state2str(disk->d_state)));
2577			/*
2578			 * Reset bumping syncid if disk disappeared in STARTING
2579			 * state.
2580			 */
2581			if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0)
2582				sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
2583#ifdef	INVARIANTS
2584		} else {
2585			KASSERT(1 == 0, ("Wrong device state (%s, %s, %s, %s).",
2586			    sc->sc_name,
2587			    g_mirror_device_state2str(sc->sc_state),
2588			    g_mirror_get_diskname(disk),
2589			    g_mirror_disk_state2str(disk->d_state)));
2590#endif
2591		}
2592		DISK_STATE_CHANGED();
2593		G_MIRROR_DEBUG(0, "Device %s: provider %s disconnected.",
2594		    sc->sc_name, g_mirror_get_diskname(disk));
2595
2596		g_mirror_destroy_disk(disk);
2597		break;
2598	case G_MIRROR_DISK_STATE_DESTROY:
2599	    {
2600		int error;
2601
2602		error = g_mirror_clear_metadata(disk);
2603		if (error != 0)
2604			return (error);
2605		DISK_STATE_CHANGED();
2606		G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.",
2607		    sc->sc_name, g_mirror_get_diskname(disk));
2608
2609		g_mirror_destroy_disk(disk);
2610		sc->sc_ndisks--;
2611		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2612			g_mirror_update_metadata(disk);
2613		}
2614		break;
2615	    }
2616	default:
2617		KASSERT(1 == 0, ("Unknown state (%u).", state));
2618		break;
2619	}
2620	return (0);
2621}
2622#undef	DISK_STATE_CHANGED
2623
2624int
2625g_mirror_read_metadata(struct g_consumer *cp, struct g_mirror_metadata *md)
2626{
2627	struct g_provider *pp;
2628	u_char *buf;
2629	int error;
2630
2631	g_topology_assert();
2632
2633	error = g_access(cp, 1, 0, 0);
2634	if (error != 0)
2635		return (error);
2636	pp = cp->provider;
2637	g_topology_unlock();
2638	/* Metadata are stored on last sector. */
2639	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
2640	    &error);
2641	g_topology_lock();
2642	g_access(cp, -1, 0, 0);
2643	if (buf == NULL) {
2644		G_MIRROR_DEBUG(1, "Cannot read metadata from %s (error=%d).",
2645		    cp->provider->name, error);
2646		return (error);
2647	}
2648
2649	/* Decode metadata. */
2650	error = mirror_metadata_decode(buf, md);
2651	g_free(buf);
2652	if (strcmp(md->md_magic, G_MIRROR_MAGIC) != 0)
2653		return (EINVAL);
2654	if (md->md_version > G_MIRROR_VERSION) {
2655		G_MIRROR_DEBUG(0,
2656		    "Kernel module is too old to handle metadata from %s.",
2657		    cp->provider->name);
2658		return (EINVAL);
2659	}
2660	if (error != 0) {
2661		G_MIRROR_DEBUG(1, "MD5 metadata hash mismatch for provider %s.",
2662		    cp->provider->name);
2663		return (error);
2664	}
2665
2666	return (0);
2667}
2668
2669static int
2670g_mirror_check_metadata(struct g_mirror_softc *sc, struct g_provider *pp,
2671    struct g_mirror_metadata *md)
2672{
2673
2674	if (g_mirror_id2disk(sc, md->md_did) != NULL) {
2675		G_MIRROR_DEBUG(1, "Disk %s (id=%u) already exists, skipping.",
2676		    pp->name, md->md_did);
2677		return (EEXIST);
2678	}
2679	if (md->md_all != sc->sc_ndisks) {
2680		G_MIRROR_DEBUG(1,
2681		    "Invalid '%s' field on disk %s (device %s), skipping.",
2682		    "md_all", pp->name, sc->sc_name);
2683		return (EINVAL);
2684	}
2685	if (md->md_slice != sc->sc_slice) {
2686		G_MIRROR_DEBUG(1,
2687		    "Invalid '%s' field on disk %s (device %s), skipping.",
2688		    "md_slice", pp->name, sc->sc_name);
2689		return (EINVAL);
2690	}
2691	if (md->md_balance != sc->sc_balance) {
2692		G_MIRROR_DEBUG(1,
2693		    "Invalid '%s' field on disk %s (device %s), skipping.",
2694		    "md_balance", pp->name, sc->sc_name);
2695		return (EINVAL);
2696	}
2697	if (md->md_mediasize != sc->sc_mediasize) {
2698		G_MIRROR_DEBUG(1,
2699		    "Invalid '%s' field on disk %s (device %s), skipping.",
2700		    "md_mediasize", pp->name, sc->sc_name);
2701		return (EINVAL);
2702	}
2703	if (sc->sc_mediasize > pp->mediasize) {
2704		G_MIRROR_DEBUG(1,
2705		    "Invalid size of disk %s (device %s), skipping.", pp->name,
2706		    sc->sc_name);
2707		return (EINVAL);
2708	}
2709	if (md->md_sectorsize != sc->sc_sectorsize) {
2710		G_MIRROR_DEBUG(1,
2711		    "Invalid '%s' field on disk %s (device %s), skipping.",
2712		    "md_sectorsize", pp->name, sc->sc_name);
2713		return (EINVAL);
2714	}
2715	if ((sc->sc_sectorsize % pp->sectorsize) != 0) {
2716		G_MIRROR_DEBUG(1,
2717		    "Invalid sector size of disk %s (device %s), skipping.",
2718		    pp->name, sc->sc_name);
2719		return (EINVAL);
2720	}
2721	if ((md->md_mflags & ~G_MIRROR_DEVICE_FLAG_MASK) != 0) {
2722		G_MIRROR_DEBUG(1,
2723		    "Invalid device flags on disk %s (device %s), skipping.",
2724		    pp->name, sc->sc_name);
2725		return (EINVAL);
2726	}
2727	if ((md->md_dflags & ~G_MIRROR_DISK_FLAG_MASK) != 0) {
2728		G_MIRROR_DEBUG(1,
2729		    "Invalid disk flags on disk %s (device %s), skipping.",
2730		    pp->name, sc->sc_name);
2731		return (EINVAL);
2732	}
2733	return (0);
2734}
2735
2736int
2737g_mirror_add_disk(struct g_mirror_softc *sc, struct g_provider *pp,
2738    struct g_mirror_metadata *md)
2739{
2740	struct g_mirror_disk *disk;
2741	int error;
2742
2743	g_topology_assert_not();
2744	G_MIRROR_DEBUG(2, "Adding disk %s.", pp->name);
2745
2746	error = g_mirror_check_metadata(sc, pp, md);
2747	if (error != 0)
2748		return (error);
2749	if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING &&
2750	    md->md_genid < sc->sc_genid) {
2751		G_MIRROR_DEBUG(0, "Component %s (device %s) broken, skipping.",
2752		    pp->name, sc->sc_name);
2753		return (EINVAL);
2754	}
2755	disk = g_mirror_init_disk(sc, pp, md, &error);
2756	if (disk == NULL)
2757		return (error);
2758	error = g_mirror_event_send(disk, G_MIRROR_DISK_STATE_NEW,
2759	    G_MIRROR_EVENT_WAIT);
2760	if (error != 0)
2761		return (error);
2762	if (md->md_version < G_MIRROR_VERSION) {
2763		G_MIRROR_DEBUG(0, "Upgrading metadata on %s (v%d->v%d).",
2764		    pp->name, md->md_version, G_MIRROR_VERSION);
2765		g_mirror_update_metadata(disk);
2766	}
2767	return (0);
2768}
2769
2770static void
2771g_mirror_destroy_delayed(void *arg, int flag)
2772{
2773	struct g_mirror_softc *sc;
2774	int error;
2775
2776	if (flag == EV_CANCEL) {
2777		G_MIRROR_DEBUG(1, "Destroying canceled.");
2778		return;
2779	}
2780	sc = arg;
2781	g_topology_unlock();
2782	sx_xlock(&sc->sc_lock);
2783	KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) == 0,
2784	    ("DESTROY flag set on %s.", sc->sc_name));
2785	KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROYING) != 0,
2786	    ("DESTROYING flag not set on %s.", sc->sc_name));
2787	G_MIRROR_DEBUG(1, "Destroying %s (delayed).", sc->sc_name);
2788	error = g_mirror_destroy(sc, G_MIRROR_DESTROY_SOFT);
2789	if (error != 0) {
2790		G_MIRROR_DEBUG(0, "Cannot destroy %s.", sc->sc_name);
2791		sx_xunlock(&sc->sc_lock);
2792	}
2793	g_topology_lock();
2794}
2795
2796static int
2797g_mirror_access(struct g_provider *pp, int acr, int acw, int ace)
2798{
2799	struct g_mirror_softc *sc;
2800	int dcr, dcw, dce, error = 0;
2801
2802	g_topology_assert();
2803	G_MIRROR_DEBUG(2, "Access request for %s: r%dw%de%d.", pp->name, acr,
2804	    acw, ace);
2805
2806	sc = pp->geom->softc;
2807	if (sc == NULL && acr <= 0 && acw <= 0 && ace <= 0)
2808		return (0);
2809	KASSERT(sc != NULL, ("NULL softc (provider=%s).", pp->name));
2810
2811	dcr = pp->acr + acr;
2812	dcw = pp->acw + acw;
2813	dce = pp->ace + ace;
2814
2815	g_topology_unlock();
2816	sx_xlock(&sc->sc_lock);
2817	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0 ||
2818	    LIST_EMPTY(&sc->sc_disks)) {
2819		if (acr > 0 || acw > 0 || ace > 0)
2820			error = ENXIO;
2821		goto end;
2822	}
2823	if (dcw == 0)
2824		g_mirror_idle(sc, dcw);
2825	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROYING) != 0) {
2826		if (acr > 0 || acw > 0 || ace > 0) {
2827			error = ENXIO;
2828			goto end;
2829		}
2830		if (dcr == 0 && dcw == 0 && dce == 0) {
2831			g_post_event(g_mirror_destroy_delayed, sc, M_WAITOK,
2832			    sc, NULL);
2833		}
2834	}
2835end:
2836	sx_xunlock(&sc->sc_lock);
2837	g_topology_lock();
2838	return (error);
2839}
2840
2841static struct g_geom *
2842g_mirror_create(struct g_class *mp, const struct g_mirror_metadata *md)
2843{
2844	struct g_mirror_softc *sc;
2845	struct g_geom *gp;
2846	int error, timeout;
2847
2848	g_topology_assert();
2849	G_MIRROR_DEBUG(1, "Creating device %s (id=%u).", md->md_name,
2850	    md->md_mid);
2851
2852	/* One disk is minimum. */
2853	if (md->md_all < 1)
2854		return (NULL);
2855	/*
2856	 * Action geom.
2857	 */
2858	gp = g_new_geomf(mp, "%s", md->md_name);
2859	sc = malloc(sizeof(*sc), M_MIRROR, M_WAITOK | M_ZERO);
2860	gp->start = g_mirror_start;
2861	gp->orphan = g_mirror_orphan;
2862	gp->access = g_mirror_access;
2863	gp->dumpconf = g_mirror_dumpconf;
2864
2865	sc->sc_id = md->md_mid;
2866	sc->sc_slice = md->md_slice;
2867	sc->sc_balance = md->md_balance;
2868	sc->sc_mediasize = md->md_mediasize;
2869	sc->sc_sectorsize = md->md_sectorsize;
2870	sc->sc_ndisks = md->md_all;
2871	sc->sc_flags = md->md_mflags;
2872	sc->sc_bump_id = 0;
2873	sc->sc_idle = 1;
2874	sc->sc_last_write = time_uptime;
2875	sc->sc_writes = 0;
2876	sx_init(&sc->sc_lock, "gmirror:lock");
2877	bioq_init(&sc->sc_queue);
2878	mtx_init(&sc->sc_queue_mtx, "gmirror:queue", NULL, MTX_DEF);
2879	bioq_init(&sc->sc_regular_delayed);
2880	bioq_init(&sc->sc_inflight);
2881	bioq_init(&sc->sc_sync_delayed);
2882	LIST_INIT(&sc->sc_disks);
2883	TAILQ_INIT(&sc->sc_events);
2884	mtx_init(&sc->sc_events_mtx, "gmirror:events", NULL, MTX_DEF);
2885	callout_init(&sc->sc_callout, CALLOUT_MPSAFE);
2886	sc->sc_state = G_MIRROR_DEVICE_STATE_STARTING;
2887	gp->softc = sc;
2888	sc->sc_geom = gp;
2889	sc->sc_provider = NULL;
2890	/*
2891	 * Synchronization geom.
2892	 */
2893	gp = g_new_geomf(mp, "%s.sync", md->md_name);
2894	gp->softc = sc;
2895	gp->orphan = g_mirror_orphan;
2896	sc->sc_sync.ds_geom = gp;
2897	sc->sc_sync.ds_ndisks = 0;
2898	error = kproc_create(g_mirror_worker, sc, &sc->sc_worker, 0, 0,
2899	    "g_mirror %s", md->md_name);
2900	if (error != 0) {
2901		G_MIRROR_DEBUG(1, "Cannot create kernel thread for %s.",
2902		    sc->sc_name);
2903		g_destroy_geom(sc->sc_sync.ds_geom);
2904		mtx_destroy(&sc->sc_events_mtx);
2905		mtx_destroy(&sc->sc_queue_mtx);
2906		sx_destroy(&sc->sc_lock);
2907		g_destroy_geom(sc->sc_geom);
2908		free(sc, M_MIRROR);
2909		return (NULL);
2910	}
2911
2912	G_MIRROR_DEBUG(1, "Device %s created (%u components, id=%u).",
2913	    sc->sc_name, sc->sc_ndisks, sc->sc_id);
2914
2915	sc->sc_rootmount = root_mount_hold("GMIRROR");
2916	G_MIRROR_DEBUG(1, "root_mount_hold %p", sc->sc_rootmount);
2917	/*
2918	 * Run timeout.
2919	 */
2920	timeout = g_mirror_timeout * hz;
2921	callout_reset(&sc->sc_callout, timeout, g_mirror_go, sc);
2922	return (sc->sc_geom);
2923}
2924
2925int
2926g_mirror_destroy(struct g_mirror_softc *sc, int how)
2927{
2928	struct g_mirror_disk *disk;
2929	struct g_provider *pp;
2930
2931	g_topology_assert_not();
2932	if (sc == NULL)
2933		return (ENXIO);
2934	sx_assert(&sc->sc_lock, SX_XLOCKED);
2935
2936	pp = sc->sc_provider;
2937	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
2938		switch (how) {
2939		case G_MIRROR_DESTROY_SOFT:
2940			G_MIRROR_DEBUG(1,
2941			    "Device %s is still open (r%dw%de%d).", pp->name,
2942			    pp->acr, pp->acw, pp->ace);
2943			return (EBUSY);
2944		case G_MIRROR_DESTROY_DELAYED:
2945			G_MIRROR_DEBUG(1,
2946			    "Device %s will be destroyed on last close.",
2947			    pp->name);
2948			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2949				if (disk->d_state ==
2950				    G_MIRROR_DISK_STATE_SYNCHRONIZING) {
2951					g_mirror_sync_stop(disk, 1);
2952				}
2953			}
2954			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROYING;
2955			return (EBUSY);
2956		case G_MIRROR_DESTROY_HARD:
2957			G_MIRROR_DEBUG(1, "Device %s is still open, so it "
2958			    "can't be definitely removed.", pp->name);
2959		}
2960	}
2961
2962	g_topology_lock();
2963	if (sc->sc_geom->softc == NULL) {
2964		g_topology_unlock();
2965		return (0);
2966	}
2967	sc->sc_geom->softc = NULL;
2968	sc->sc_sync.ds_geom->softc = NULL;
2969	g_topology_unlock();
2970
2971	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2972	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_WAIT;
2973	G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
2974	sx_xunlock(&sc->sc_lock);
2975	mtx_lock(&sc->sc_queue_mtx);
2976	wakeup(sc);
2977	mtx_unlock(&sc->sc_queue_mtx);
2978	G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, &sc->sc_worker);
2979	while (sc->sc_worker != NULL)
2980		tsleep(&sc->sc_worker, PRIBIO, "m:destroy", hz / 5);
2981	G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, &sc->sc_worker);
2982	sx_xlock(&sc->sc_lock);
2983	g_mirror_destroy_device(sc);
2984	free(sc, M_MIRROR);
2985	return (0);
2986}
2987
2988static void
2989g_mirror_taste_orphan(struct g_consumer *cp)
2990{
2991
2992	KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
2993	    cp->provider->name));
2994}
2995
2996static struct g_geom *
2997g_mirror_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
2998{
2999	struct g_mirror_metadata md;
3000	struct g_mirror_softc *sc;
3001	struct g_consumer *cp;
3002	struct g_geom *gp;
3003	int error;
3004
3005	g_topology_assert();
3006	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
3007	G_MIRROR_DEBUG(2, "Tasting %s.", pp->name);
3008
3009	gp = g_new_geomf(mp, "mirror:taste");
3010	/*
3011	 * This orphan function should be never called.
3012	 */
3013	gp->orphan = g_mirror_taste_orphan;
3014	cp = g_new_consumer(gp);
3015	g_attach(cp, pp);
3016	error = g_mirror_read_metadata(cp, &md);
3017	g_detach(cp);
3018	g_destroy_consumer(cp);
3019	g_destroy_geom(gp);
3020	if (error != 0)
3021		return (NULL);
3022	gp = NULL;
3023
3024	if (md.md_provider[0] != '\0' &&
3025	    !g_compare_names(md.md_provider, pp->name))
3026		return (NULL);
3027	if (md.md_provsize != 0 && md.md_provsize != pp->mediasize)
3028		return (NULL);
3029	if ((md.md_dflags & G_MIRROR_DISK_FLAG_INACTIVE) != 0) {
3030		G_MIRROR_DEBUG(0,
3031		    "Device %s: provider %s marked as inactive, skipping.",
3032		    md.md_name, pp->name);
3033		return (NULL);
3034	}
3035	if (g_mirror_debug >= 2)
3036		mirror_metadata_dump(&md);
3037
3038	/*
3039	 * Let's check if device already exists.
3040	 */
3041	sc = NULL;
3042	LIST_FOREACH(gp, &mp->geom, geom) {
3043		sc = gp->softc;
3044		if (sc == NULL)
3045			continue;
3046		if (sc->sc_sync.ds_geom == gp)
3047			continue;
3048		if (strcmp(md.md_name, sc->sc_name) != 0)
3049			continue;
3050		if (md.md_mid != sc->sc_id) {
3051			G_MIRROR_DEBUG(0, "Device %s already configured.",
3052			    sc->sc_name);
3053			return (NULL);
3054		}
3055		break;
3056	}
3057	if (gp == NULL) {
3058		gp = g_mirror_create(mp, &md);
3059		if (gp == NULL) {
3060			G_MIRROR_DEBUG(0, "Cannot create device %s.",
3061			    md.md_name);
3062			return (NULL);
3063		}
3064		sc = gp->softc;
3065	}
3066	G_MIRROR_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
3067	g_topology_unlock();
3068	sx_xlock(&sc->sc_lock);
3069	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_TASTING;
3070	error = g_mirror_add_disk(sc, pp, &md);
3071	if (error != 0) {
3072		G_MIRROR_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
3073		    pp->name, gp->name, error);
3074		if (LIST_EMPTY(&sc->sc_disks)) {
3075			g_cancel_event(sc);
3076			g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
3077			g_topology_lock();
3078			return (NULL);
3079		}
3080		gp = NULL;
3081	}
3082	sc->sc_flags &= ~G_MIRROR_DEVICE_FLAG_TASTING;
3083	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
3084		g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
3085		g_topology_lock();
3086		return (NULL);
3087	}
3088	sx_xunlock(&sc->sc_lock);
3089	g_topology_lock();
3090	return (gp);
3091}
3092
3093static int
3094g_mirror_destroy_geom(struct gctl_req *req __unused,
3095    struct g_class *mp __unused, struct g_geom *gp)
3096{
3097	struct g_mirror_softc *sc;
3098	int error;
3099
3100	g_topology_unlock();
3101	sc = gp->softc;
3102	sx_xlock(&sc->sc_lock);
3103	g_cancel_event(sc);
3104	error = g_mirror_destroy(gp->softc, G_MIRROR_DESTROY_SOFT);
3105	if (error != 0)
3106		sx_xunlock(&sc->sc_lock);
3107	g_topology_lock();
3108	return (error);
3109}
3110
3111static void
3112g_mirror_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
3113    struct g_consumer *cp, struct g_provider *pp)
3114{
3115	struct g_mirror_softc *sc;
3116
3117	g_topology_assert();
3118
3119	sc = gp->softc;
3120	if (sc == NULL)
3121		return;
3122	/* Skip synchronization geom. */
3123	if (gp == sc->sc_sync.ds_geom)
3124		return;
3125	if (pp != NULL) {
3126		/* Nothing here. */
3127	} else if (cp != NULL) {
3128		struct g_mirror_disk *disk;
3129
3130		disk = cp->private;
3131		if (disk == NULL)
3132			return;
3133		g_topology_unlock();
3134		sx_xlock(&sc->sc_lock);
3135		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)disk->d_id);
3136		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
3137			sbuf_printf(sb, "%s<Synchronized>", indent);
3138			if (disk->d_sync.ds_offset == 0)
3139				sbuf_printf(sb, "0%%");
3140			else {
3141				sbuf_printf(sb, "%u%%",
3142				    (u_int)((disk->d_sync.ds_offset * 100) /
3143				    sc->sc_provider->mediasize));
3144			}
3145			sbuf_printf(sb, "</Synchronized>\n");
3146			if (disk->d_sync.ds_offset > 0) {
3147				sbuf_printf(sb, "%s<BytesSynced>%jd"
3148				    "</BytesSynced>\n", indent,
3149				    (intmax_t)disk->d_sync.ds_offset);
3150			}
3151		}
3152		sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent,
3153		    disk->d_sync.ds_syncid);
3154		sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent,
3155		    disk->d_genid);
3156		sbuf_printf(sb, "%s<Flags>", indent);
3157		if (disk->d_flags == 0)
3158			sbuf_printf(sb, "NONE");
3159		else {
3160			int first = 1;
3161
3162#define	ADD_FLAG(flag, name)	do {					\
3163	if ((disk->d_flags & (flag)) != 0) {				\
3164		if (!first)						\
3165			sbuf_printf(sb, ", ");				\
3166		else							\
3167			first = 0;					\
3168		sbuf_printf(sb, name);					\
3169	}								\
3170} while (0)
3171			ADD_FLAG(G_MIRROR_DISK_FLAG_DIRTY, "DIRTY");
3172			ADD_FLAG(G_MIRROR_DISK_FLAG_HARDCODED, "HARDCODED");
3173			ADD_FLAG(G_MIRROR_DISK_FLAG_INACTIVE, "INACTIVE");
3174			ADD_FLAG(G_MIRROR_DISK_FLAG_SYNCHRONIZING,
3175			    "SYNCHRONIZING");
3176			ADD_FLAG(G_MIRROR_DISK_FLAG_FORCE_SYNC, "FORCE_SYNC");
3177			ADD_FLAG(G_MIRROR_DISK_FLAG_BROKEN, "BROKEN");
3178#undef	ADD_FLAG
3179		}
3180		sbuf_printf(sb, "</Flags>\n");
3181		sbuf_printf(sb, "%s<Priority>%u</Priority>\n", indent,
3182		    disk->d_priority);
3183		sbuf_printf(sb, "%s<State>%s</State>\n", indent,
3184		    g_mirror_disk_state2str(disk->d_state));
3185		sx_xunlock(&sc->sc_lock);
3186		g_topology_lock();
3187	} else {
3188		g_topology_unlock();
3189		sx_xlock(&sc->sc_lock);
3190		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
3191		sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent, sc->sc_syncid);
3192		sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent, sc->sc_genid);
3193		sbuf_printf(sb, "%s<Flags>", indent);
3194		if (sc->sc_flags == 0)
3195			sbuf_printf(sb, "NONE");
3196		else {
3197			int first = 1;
3198
3199#define	ADD_FLAG(flag, name)	do {					\
3200	if ((sc->sc_flags & (flag)) != 0) {				\
3201		if (!first)						\
3202			sbuf_printf(sb, ", ");				\
3203		else							\
3204			first = 0;					\
3205		sbuf_printf(sb, name);					\
3206	}								\
3207} while (0)
3208			ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOFAILSYNC, "NOFAILSYNC");
3209			ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOAUTOSYNC, "NOAUTOSYNC");
3210#undef	ADD_FLAG
3211		}
3212		sbuf_printf(sb, "</Flags>\n");
3213		sbuf_printf(sb, "%s<Slice>%u</Slice>\n", indent,
3214		    (u_int)sc->sc_slice);
3215		sbuf_printf(sb, "%s<Balance>%s</Balance>\n", indent,
3216		    balance_name(sc->sc_balance));
3217		sbuf_printf(sb, "%s<Components>%u</Components>\n", indent,
3218		    sc->sc_ndisks);
3219		sbuf_printf(sb, "%s<State>", indent);
3220		if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
3221			sbuf_printf(sb, "%s", "STARTING");
3222		else if (sc->sc_ndisks ==
3223		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE))
3224			sbuf_printf(sb, "%s", "COMPLETE");
3225		else
3226			sbuf_printf(sb, "%s", "DEGRADED");
3227		sbuf_printf(sb, "</State>\n");
3228		sx_xunlock(&sc->sc_lock);
3229		g_topology_lock();
3230	}
3231}
3232
3233static void
3234g_mirror_shutdown_post_sync(void *arg, int howto)
3235{
3236	struct g_class *mp;
3237	struct g_geom *gp, *gp2;
3238	struct g_mirror_softc *sc;
3239	int error;
3240
3241	mp = arg;
3242	DROP_GIANT();
3243	g_topology_lock();
3244	g_mirror_shutdown = 1;
3245	LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
3246		if ((sc = gp->softc) == NULL)
3247			continue;
3248		/* Skip synchronization geom. */
3249		if (gp == sc->sc_sync.ds_geom)
3250			continue;
3251		g_topology_unlock();
3252		sx_xlock(&sc->sc_lock);
3253		g_mirror_idle(sc, -1);
3254		g_cancel_event(sc);
3255		error = g_mirror_destroy(sc, G_MIRROR_DESTROY_DELAYED);
3256		if (error != 0)
3257			sx_xunlock(&sc->sc_lock);
3258		g_topology_lock();
3259	}
3260	g_topology_unlock();
3261	PICKUP_GIANT();
3262}
3263
3264static void
3265g_mirror_init(struct g_class *mp)
3266{
3267
3268	g_mirror_post_sync = EVENTHANDLER_REGISTER(shutdown_post_sync,
3269	    g_mirror_shutdown_post_sync, mp, SHUTDOWN_PRI_FIRST);
3270	if (g_mirror_post_sync == NULL)
3271		G_MIRROR_DEBUG(0, "Warning! Cannot register shutdown event.");
3272}
3273
3274static void
3275g_mirror_fini(struct g_class *mp)
3276{
3277
3278	if (g_mirror_post_sync != NULL)
3279		EVENTHANDLER_DEREGISTER(shutdown_post_sync, g_mirror_post_sync);
3280}
3281
3282DECLARE_GEOM_CLASS(g_mirror_class, g_mirror);
3283