xref: /freebsd/sys/geom/mirror/g_mirror.c (revision 094fc1ed0f2627525c7b0342efcbad5be7a8546a)
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("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/fail.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/limits.h>
36 #include <sys/lock.h>
37 #include <sys/mutex.h>
38 #include <sys/bio.h>
39 #include <sys/sbuf.h>
40 #include <sys/sysctl.h>
41 #include <sys/malloc.h>
42 #include <sys/eventhandler.h>
43 #include <vm/uma.h>
44 #include <geom/geom.h>
45 #include <sys/proc.h>
46 #include <sys/kthread.h>
47 #include <sys/sched.h>
48 #include <geom/mirror/g_mirror.h>
49 
50 FEATURE(geom_mirror, "GEOM mirroring support");
51 
52 static MALLOC_DEFINE(M_MIRROR, "mirror_data", "GEOM_MIRROR Data");
53 
54 SYSCTL_DECL(_kern_geom);
55 static SYSCTL_NODE(_kern_geom, OID_AUTO, mirror, CTLFLAG_RW, 0,
56     "GEOM_MIRROR stuff");
57 u_int g_mirror_debug = 0;
58 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, debug, CTLFLAG_RWTUN, &g_mirror_debug, 0,
59     "Debug level");
60 static u_int g_mirror_timeout = 4;
61 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, timeout, CTLFLAG_RWTUN, &g_mirror_timeout,
62     0, "Time to wait on all mirror components");
63 static u_int g_mirror_idletime = 5;
64 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, idletime, CTLFLAG_RWTUN,
65     &g_mirror_idletime, 0, "Mark components as clean when idling");
66 static u_int g_mirror_disconnect_on_failure = 1;
67 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, disconnect_on_failure, CTLFLAG_RWTUN,
68     &g_mirror_disconnect_on_failure, 0, "Disconnect component on I/O failure.");
69 static u_int g_mirror_syncreqs = 2;
70 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, sync_requests, CTLFLAG_RDTUN,
71     &g_mirror_syncreqs, 0, "Parallel synchronization I/O requests.");
72 
73 #define	MSLEEP(ident, mtx, priority, wmesg, timeout)	do {		\
74 	G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, (ident));	\
75 	msleep((ident), (mtx), (priority), (wmesg), (timeout));		\
76 	G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, (ident));	\
77 } while (0)
78 
79 static eventhandler_tag g_mirror_post_sync = NULL;
80 static int g_mirror_shutdown = 0;
81 
82 static g_ctl_destroy_geom_t g_mirror_destroy_geom;
83 static g_taste_t g_mirror_taste;
84 static g_init_t g_mirror_init;
85 static g_fini_t g_mirror_fini;
86 static g_provgone_t g_mirror_providergone;
87 static g_resize_t g_mirror_resize;
88 
89 struct g_class g_mirror_class = {
90 	.name = G_MIRROR_CLASS_NAME,
91 	.version = G_VERSION,
92 	.ctlreq = g_mirror_config,
93 	.taste = g_mirror_taste,
94 	.destroy_geom = g_mirror_destroy_geom,
95 	.init = g_mirror_init,
96 	.fini = g_mirror_fini,
97 	.providergone = g_mirror_providergone,
98 	.resize = g_mirror_resize
99 };
100 
101 
102 static void g_mirror_destroy_provider(struct g_mirror_softc *sc);
103 static int g_mirror_update_disk(struct g_mirror_disk *disk, u_int state);
104 static void g_mirror_update_device(struct g_mirror_softc *sc, bool force);
105 static void g_mirror_dumpconf(struct sbuf *sb, const char *indent,
106     struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp);
107 static void g_mirror_sync_stop(struct g_mirror_disk *disk, int type);
108 static void g_mirror_register_request(struct bio *bp);
109 static void g_mirror_sync_release(struct g_mirror_softc *sc);
110 
111 
112 static const char *
113 g_mirror_disk_state2str(int state)
114 {
115 
116 	switch (state) {
117 	case G_MIRROR_DISK_STATE_NONE:
118 		return ("NONE");
119 	case G_MIRROR_DISK_STATE_NEW:
120 		return ("NEW");
121 	case G_MIRROR_DISK_STATE_ACTIVE:
122 		return ("ACTIVE");
123 	case G_MIRROR_DISK_STATE_STALE:
124 		return ("STALE");
125 	case G_MIRROR_DISK_STATE_SYNCHRONIZING:
126 		return ("SYNCHRONIZING");
127 	case G_MIRROR_DISK_STATE_DISCONNECTED:
128 		return ("DISCONNECTED");
129 	case G_MIRROR_DISK_STATE_DESTROY:
130 		return ("DESTROY");
131 	default:
132 		return ("INVALID");
133 	}
134 }
135 
136 static const char *
137 g_mirror_device_state2str(int state)
138 {
139 
140 	switch (state) {
141 	case G_MIRROR_DEVICE_STATE_STARTING:
142 		return ("STARTING");
143 	case G_MIRROR_DEVICE_STATE_RUNNING:
144 		return ("RUNNING");
145 	default:
146 		return ("INVALID");
147 	}
148 }
149 
150 static const char *
151 g_mirror_get_diskname(struct g_mirror_disk *disk)
152 {
153 
154 	if (disk->d_consumer == NULL || disk->d_consumer->provider == NULL)
155 		return ("[unknown]");
156 	return (disk->d_name);
157 }
158 
159 /*
160  * --- Events handling functions ---
161  * Events in geom_mirror are used to maintain disks and device status
162  * from one thread to simplify locking.
163  */
164 static void
165 g_mirror_event_free(struct g_mirror_event *ep)
166 {
167 
168 	free(ep, M_MIRROR);
169 }
170 
171 int
172 g_mirror_event_send(void *arg, int state, int flags)
173 {
174 	struct g_mirror_softc *sc;
175 	struct g_mirror_disk *disk;
176 	struct g_mirror_event *ep;
177 	int error;
178 
179 	ep = malloc(sizeof(*ep), M_MIRROR, M_WAITOK);
180 	G_MIRROR_DEBUG(4, "%s: Sending event %p.", __func__, ep);
181 	if ((flags & G_MIRROR_EVENT_DEVICE) != 0) {
182 		disk = NULL;
183 		sc = arg;
184 	} else {
185 		disk = arg;
186 		sc = disk->d_softc;
187 	}
188 	ep->e_disk = disk;
189 	ep->e_state = state;
190 	ep->e_flags = flags;
191 	ep->e_error = 0;
192 	mtx_lock(&sc->sc_events_mtx);
193 	TAILQ_INSERT_TAIL(&sc->sc_events, ep, e_next);
194 	mtx_unlock(&sc->sc_events_mtx);
195 	G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
196 	mtx_lock(&sc->sc_queue_mtx);
197 	wakeup(sc);
198 	mtx_unlock(&sc->sc_queue_mtx);
199 	if ((flags & G_MIRROR_EVENT_DONTWAIT) != 0)
200 		return (0);
201 	sx_assert(&sc->sc_lock, SX_XLOCKED);
202 	G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, ep);
203 	sx_xunlock(&sc->sc_lock);
204 	while ((ep->e_flags & G_MIRROR_EVENT_DONE) == 0) {
205 		mtx_lock(&sc->sc_events_mtx);
206 		MSLEEP(ep, &sc->sc_events_mtx, PRIBIO | PDROP, "m:event",
207 		    hz * 5);
208 	}
209 	error = ep->e_error;
210 	g_mirror_event_free(ep);
211 	sx_xlock(&sc->sc_lock);
212 	return (error);
213 }
214 
215 static struct g_mirror_event *
216 g_mirror_event_get(struct g_mirror_softc *sc)
217 {
218 	struct g_mirror_event *ep;
219 
220 	mtx_lock(&sc->sc_events_mtx);
221 	ep = TAILQ_FIRST(&sc->sc_events);
222 	mtx_unlock(&sc->sc_events_mtx);
223 	return (ep);
224 }
225 
226 static void
227 g_mirror_event_remove(struct g_mirror_softc *sc, struct g_mirror_event *ep)
228 {
229 
230 	mtx_lock(&sc->sc_events_mtx);
231 	TAILQ_REMOVE(&sc->sc_events, ep, e_next);
232 	mtx_unlock(&sc->sc_events_mtx);
233 }
234 
235 static void
236 g_mirror_event_cancel(struct g_mirror_disk *disk)
237 {
238 	struct g_mirror_softc *sc;
239 	struct g_mirror_event *ep, *tmpep;
240 
241 	sc = disk->d_softc;
242 	sx_assert(&sc->sc_lock, SX_XLOCKED);
243 
244 	mtx_lock(&sc->sc_events_mtx);
245 	TAILQ_FOREACH_SAFE(ep, &sc->sc_events, e_next, tmpep) {
246 		if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0)
247 			continue;
248 		if (ep->e_disk != disk)
249 			continue;
250 		TAILQ_REMOVE(&sc->sc_events, ep, e_next);
251 		if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
252 			g_mirror_event_free(ep);
253 		else {
254 			ep->e_error = ECANCELED;
255 			wakeup(ep);
256 		}
257 	}
258 	mtx_unlock(&sc->sc_events_mtx);
259 }
260 
261 /*
262  * Return the number of disks in given state.
263  * If state is equal to -1, count all connected disks.
264  */
265 u_int
266 g_mirror_ndisks(struct g_mirror_softc *sc, int state)
267 {
268 	struct g_mirror_disk *disk;
269 	u_int n = 0;
270 
271 	sx_assert(&sc->sc_lock, SX_LOCKED);
272 
273 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
274 		if (state == -1 || disk->d_state == state)
275 			n++;
276 	}
277 	return (n);
278 }
279 
280 /*
281  * Find a disk in mirror by its disk ID.
282  */
283 static struct g_mirror_disk *
284 g_mirror_id2disk(struct g_mirror_softc *sc, uint32_t id)
285 {
286 	struct g_mirror_disk *disk;
287 
288 	sx_assert(&sc->sc_lock, SX_XLOCKED);
289 
290 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
291 		if (disk->d_id == id)
292 			return (disk);
293 	}
294 	return (NULL);
295 }
296 
297 static u_int
298 g_mirror_nrequests(struct g_mirror_softc *sc, struct g_consumer *cp)
299 {
300 	struct bio *bp;
301 	u_int nreqs = 0;
302 
303 	mtx_lock(&sc->sc_queue_mtx);
304 	TAILQ_FOREACH(bp, &sc->sc_queue.queue, bio_queue) {
305 		if (bp->bio_from == cp)
306 			nreqs++;
307 	}
308 	mtx_unlock(&sc->sc_queue_mtx);
309 	return (nreqs);
310 }
311 
312 static int
313 g_mirror_is_busy(struct g_mirror_softc *sc, struct g_consumer *cp)
314 {
315 
316 	if (cp->index > 0) {
317 		G_MIRROR_DEBUG(2,
318 		    "I/O requests for %s exist, can't destroy it now.",
319 		    cp->provider->name);
320 		return (1);
321 	}
322 	if (g_mirror_nrequests(sc, cp) > 0) {
323 		G_MIRROR_DEBUG(2,
324 		    "I/O requests for %s in queue, can't destroy it now.",
325 		    cp->provider->name);
326 		return (1);
327 	}
328 	return (0);
329 }
330 
331 static void
332 g_mirror_destroy_consumer(void *arg, int flags __unused)
333 {
334 	struct g_consumer *cp;
335 
336 	g_topology_assert();
337 
338 	cp = arg;
339 	G_MIRROR_DEBUG(1, "Consumer %s destroyed.", cp->provider->name);
340 	g_detach(cp);
341 	g_destroy_consumer(cp);
342 }
343 
344 static void
345 g_mirror_kill_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
346 {
347 	struct g_provider *pp;
348 	int retaste_wait;
349 
350 	g_topology_assert();
351 
352 	cp->private = NULL;
353 	if (g_mirror_is_busy(sc, cp))
354 		return;
355 	pp = cp->provider;
356 	retaste_wait = 0;
357 	if (cp->acw == 1) {
358 		if ((pp->geom->flags & G_GEOM_WITHER) == 0)
359 			retaste_wait = 1;
360 	}
361 	G_MIRROR_DEBUG(2, "Access %s r%dw%de%d = %d", pp->name, -cp->acr,
362 	    -cp->acw, -cp->ace, 0);
363 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
364 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
365 	if (retaste_wait) {
366 		/*
367 		 * After retaste event was send (inside g_access()), we can send
368 		 * event to detach and destroy consumer.
369 		 * A class, which has consumer to the given provider connected
370 		 * will not receive retaste event for the provider.
371 		 * This is the way how I ignore retaste events when I close
372 		 * consumers opened for write: I detach and destroy consumer
373 		 * after retaste event is sent.
374 		 */
375 		g_post_event(g_mirror_destroy_consumer, cp, M_WAITOK, NULL);
376 		return;
377 	}
378 	G_MIRROR_DEBUG(1, "Consumer %s destroyed.", pp->name);
379 	g_detach(cp);
380 	g_destroy_consumer(cp);
381 }
382 
383 static int
384 g_mirror_connect_disk(struct g_mirror_disk *disk, struct g_provider *pp)
385 {
386 	struct g_consumer *cp;
387 	int error;
388 
389 	g_topology_assert_not();
390 	KASSERT(disk->d_consumer == NULL,
391 	    ("Disk already connected (device %s).", disk->d_softc->sc_name));
392 
393 	g_topology_lock();
394 	cp = g_new_consumer(disk->d_softc->sc_geom);
395 	cp->flags |= G_CF_DIRECT_RECEIVE;
396 	error = g_attach(cp, pp);
397 	if (error != 0) {
398 		g_destroy_consumer(cp);
399 		g_topology_unlock();
400 		return (error);
401 	}
402 	error = g_access(cp, 1, 1, 1);
403 	if (error != 0) {
404 		g_detach(cp);
405 		g_destroy_consumer(cp);
406 		g_topology_unlock();
407 		G_MIRROR_DEBUG(0, "Cannot open consumer %s (error=%d).",
408 		    pp->name, error);
409 		return (error);
410 	}
411 	g_topology_unlock();
412 	disk->d_consumer = cp;
413 	disk->d_consumer->private = disk;
414 	disk->d_consumer->index = 0;
415 
416 	G_MIRROR_DEBUG(2, "Disk %s connected.", g_mirror_get_diskname(disk));
417 	return (0);
418 }
419 
420 static void
421 g_mirror_disconnect_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
422 {
423 
424 	g_topology_assert();
425 
426 	if (cp == NULL)
427 		return;
428 	if (cp->provider != NULL)
429 		g_mirror_kill_consumer(sc, cp);
430 	else
431 		g_destroy_consumer(cp);
432 }
433 
434 /*
435  * Initialize disk. This means allocate memory, create consumer, attach it
436  * to the provider and open access (r1w1e1) to it.
437  */
438 static struct g_mirror_disk *
439 g_mirror_init_disk(struct g_mirror_softc *sc, struct g_provider *pp,
440     struct g_mirror_metadata *md, int *errorp)
441 {
442 	struct g_mirror_disk *disk;
443 	int i, error;
444 
445 	disk = malloc(sizeof(*disk), M_MIRROR, M_NOWAIT | M_ZERO);
446 	if (disk == NULL) {
447 		error = ENOMEM;
448 		goto fail;
449 	}
450 	disk->d_softc = sc;
451 	error = g_mirror_connect_disk(disk, pp);
452 	if (error != 0)
453 		goto fail;
454 	disk->d_id = md->md_did;
455 	disk->d_state = G_MIRROR_DISK_STATE_NONE;
456 	disk->d_priority = md->md_priority;
457 	disk->d_flags = md->md_dflags;
458 	error = g_getattr("GEOM::candelete", disk->d_consumer, &i);
459 	if (error == 0 && i != 0)
460 		disk->d_flags |= G_MIRROR_DISK_FLAG_CANDELETE;
461 	if (md->md_provider[0] != '\0')
462 		disk->d_flags |= G_MIRROR_DISK_FLAG_HARDCODED;
463 	disk->d_sync.ds_consumer = NULL;
464 	disk->d_sync.ds_offset = md->md_sync_offset;
465 	disk->d_sync.ds_offset_done = md->md_sync_offset;
466 	disk->d_genid = md->md_genid;
467 	disk->d_sync.ds_syncid = md->md_syncid;
468 	if (errorp != NULL)
469 		*errorp = 0;
470 	return (disk);
471 fail:
472 	if (errorp != NULL)
473 		*errorp = error;
474 	if (disk != NULL)
475 		free(disk, M_MIRROR);
476 	return (NULL);
477 }
478 
479 static void
480 g_mirror_destroy_disk(struct g_mirror_disk *disk)
481 {
482 	struct g_mirror_softc *sc;
483 
484 	g_topology_assert_not();
485 	sc = disk->d_softc;
486 	sx_assert(&sc->sc_lock, SX_XLOCKED);
487 
488 	LIST_REMOVE(disk, d_next);
489 	g_mirror_event_cancel(disk);
490 	if (sc->sc_hint == disk)
491 		sc->sc_hint = NULL;
492 	switch (disk->d_state) {
493 	case G_MIRROR_DISK_STATE_SYNCHRONIZING:
494 		g_mirror_sync_stop(disk, 1);
495 		/* FALLTHROUGH */
496 	case G_MIRROR_DISK_STATE_NEW:
497 	case G_MIRROR_DISK_STATE_STALE:
498 	case G_MIRROR_DISK_STATE_ACTIVE:
499 		g_topology_lock();
500 		g_mirror_disconnect_consumer(sc, disk->d_consumer);
501 		g_topology_unlock();
502 		free(disk, M_MIRROR);
503 		break;
504 	default:
505 		KASSERT(0 == 1, ("Wrong disk state (%s, %s).",
506 		    g_mirror_get_diskname(disk),
507 		    g_mirror_disk_state2str(disk->d_state)));
508 	}
509 }
510 
511 static void
512 g_mirror_free_device(struct g_mirror_softc *sc)
513 {
514 
515 	mtx_destroy(&sc->sc_queue_mtx);
516 	mtx_destroy(&sc->sc_events_mtx);
517 	mtx_destroy(&sc->sc_done_mtx);
518 	sx_destroy(&sc->sc_lock);
519 	free(sc, M_MIRROR);
520 }
521 
522 static void
523 g_mirror_providergone(struct g_provider *pp)
524 {
525 	struct g_mirror_softc *sc = pp->private;
526 
527 	if ((--sc->sc_refcnt) == 0)
528 		g_mirror_free_device(sc);
529 }
530 
531 static void
532 g_mirror_destroy_device(struct g_mirror_softc *sc)
533 {
534 	struct g_mirror_disk *disk;
535 	struct g_mirror_event *ep;
536 	struct g_geom *gp;
537 	struct g_consumer *cp, *tmpcp;
538 
539 	g_topology_assert_not();
540 	sx_assert(&sc->sc_lock, SX_XLOCKED);
541 
542 	gp = sc->sc_geom;
543 	if (sc->sc_provider != NULL)
544 		g_mirror_destroy_provider(sc);
545 	for (disk = LIST_FIRST(&sc->sc_disks); disk != NULL;
546 	    disk = LIST_FIRST(&sc->sc_disks)) {
547 		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
548 		g_mirror_update_metadata(disk);
549 		g_mirror_destroy_disk(disk);
550 	}
551 	while ((ep = g_mirror_event_get(sc)) != NULL) {
552 		g_mirror_event_remove(sc, ep);
553 		if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
554 			g_mirror_event_free(ep);
555 		else {
556 			ep->e_error = ECANCELED;
557 			ep->e_flags |= G_MIRROR_EVENT_DONE;
558 			G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, ep);
559 			mtx_lock(&sc->sc_events_mtx);
560 			wakeup(ep);
561 			mtx_unlock(&sc->sc_events_mtx);
562 		}
563 	}
564 	callout_drain(&sc->sc_callout);
565 
566 	g_topology_lock();
567 	LIST_FOREACH_SAFE(cp, &sc->sc_sync.ds_geom->consumer, consumer, tmpcp) {
568 		g_mirror_disconnect_consumer(sc, cp);
569 	}
570 	g_wither_geom(sc->sc_sync.ds_geom, ENXIO);
571 	G_MIRROR_DEBUG(0, "Device %s destroyed.", gp->name);
572 	g_wither_geom(gp, ENXIO);
573 	sx_xunlock(&sc->sc_lock);
574 	if ((--sc->sc_refcnt) == 0)
575 		g_mirror_free_device(sc);
576 	g_topology_unlock();
577 }
578 
579 static void
580 g_mirror_orphan(struct g_consumer *cp)
581 {
582 	struct g_mirror_disk *disk;
583 
584 	g_topology_assert();
585 
586 	disk = cp->private;
587 	if (disk == NULL)
588 		return;
589 	disk->d_softc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
590 	g_mirror_event_send(disk, G_MIRROR_DISK_STATE_DISCONNECTED,
591 	    G_MIRROR_EVENT_DONTWAIT);
592 }
593 
594 /*
595  * Function should return the next active disk on the list.
596  * It is possible that it will be the same disk as given.
597  * If there are no active disks on list, NULL is returned.
598  */
599 static __inline struct g_mirror_disk *
600 g_mirror_find_next(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
601 {
602 	struct g_mirror_disk *dp;
603 
604 	for (dp = LIST_NEXT(disk, d_next); dp != disk;
605 	    dp = LIST_NEXT(dp, d_next)) {
606 		if (dp == NULL)
607 			dp = LIST_FIRST(&sc->sc_disks);
608 		if (dp->d_state == G_MIRROR_DISK_STATE_ACTIVE)
609 			break;
610 	}
611 	if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
612 		return (NULL);
613 	return (dp);
614 }
615 
616 static struct g_mirror_disk *
617 g_mirror_get_disk(struct g_mirror_softc *sc)
618 {
619 	struct g_mirror_disk *disk;
620 
621 	if (sc->sc_hint == NULL) {
622 		sc->sc_hint = LIST_FIRST(&sc->sc_disks);
623 		if (sc->sc_hint == NULL)
624 			return (NULL);
625 	}
626 	disk = sc->sc_hint;
627 	if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE) {
628 		disk = g_mirror_find_next(sc, disk);
629 		if (disk == NULL)
630 			return (NULL);
631 	}
632 	sc->sc_hint = g_mirror_find_next(sc, disk);
633 	return (disk);
634 }
635 
636 static int
637 g_mirror_write_metadata(struct g_mirror_disk *disk,
638     struct g_mirror_metadata *md)
639 {
640 	struct g_mirror_softc *sc;
641 	struct g_consumer *cp;
642 	off_t offset, length;
643 	u_char *sector;
644 	int error = 0;
645 
646 	g_topology_assert_not();
647 	sc = disk->d_softc;
648 	sx_assert(&sc->sc_lock, SX_LOCKED);
649 
650 	cp = disk->d_consumer;
651 	KASSERT(cp != NULL, ("NULL consumer (%s).", sc->sc_name));
652 	KASSERT(cp->provider != NULL, ("NULL provider (%s).", sc->sc_name));
653 	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
654 	    ("Consumer %s closed? (r%dw%de%d).", cp->provider->name, cp->acr,
655 	    cp->acw, cp->ace));
656 	length = cp->provider->sectorsize;
657 	offset = cp->provider->mediasize - length;
658 	sector = malloc((size_t)length, M_MIRROR, M_WAITOK | M_ZERO);
659 	if (md != NULL &&
660 	    (sc->sc_flags & G_MIRROR_DEVICE_FLAG_WIPE) == 0) {
661 		/*
662 		 * Handle the case, when the size of parent provider reduced.
663 		 */
664 		if (offset < md->md_mediasize)
665 			error = ENOSPC;
666 		else
667 			mirror_metadata_encode(md, sector);
668 	}
669 	KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_metadata_write, error);
670 	if (error == 0)
671 		error = g_write_data(cp, offset, sector, length);
672 	free(sector, M_MIRROR);
673 	if (error != 0) {
674 		if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
675 			disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
676 			G_MIRROR_DEBUG(0, "Cannot write metadata on %s "
677 			    "(device=%s, error=%d).",
678 			    g_mirror_get_diskname(disk), sc->sc_name, error);
679 		} else {
680 			G_MIRROR_DEBUG(1, "Cannot write metadata on %s "
681 			    "(device=%s, error=%d).",
682 			    g_mirror_get_diskname(disk), sc->sc_name, error);
683 		}
684 		if (g_mirror_disconnect_on_failure &&
685 		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1) {
686 			sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
687 			g_mirror_event_send(disk,
688 			    G_MIRROR_DISK_STATE_DISCONNECTED,
689 			    G_MIRROR_EVENT_DONTWAIT);
690 		}
691 	}
692 	return (error);
693 }
694 
695 static int
696 g_mirror_clear_metadata(struct g_mirror_disk *disk)
697 {
698 	int error;
699 
700 	g_topology_assert_not();
701 	sx_assert(&disk->d_softc->sc_lock, SX_LOCKED);
702 
703 	if (disk->d_softc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
704 		return (0);
705 	error = g_mirror_write_metadata(disk, NULL);
706 	if (error == 0) {
707 		G_MIRROR_DEBUG(2, "Metadata on %s cleared.",
708 		    g_mirror_get_diskname(disk));
709 	} else {
710 		G_MIRROR_DEBUG(0,
711 		    "Cannot clear metadata on disk %s (error=%d).",
712 		    g_mirror_get_diskname(disk), error);
713 	}
714 	return (error);
715 }
716 
717 void
718 g_mirror_fill_metadata(struct g_mirror_softc *sc, struct g_mirror_disk *disk,
719     struct g_mirror_metadata *md)
720 {
721 
722 	strlcpy(md->md_magic, G_MIRROR_MAGIC, sizeof(md->md_magic));
723 	md->md_version = G_MIRROR_VERSION;
724 	strlcpy(md->md_name, sc->sc_name, sizeof(md->md_name));
725 	md->md_mid = sc->sc_id;
726 	md->md_all = sc->sc_ndisks;
727 	md->md_slice = sc->sc_slice;
728 	md->md_balance = sc->sc_balance;
729 	md->md_genid = sc->sc_genid;
730 	md->md_mediasize = sc->sc_mediasize;
731 	md->md_sectorsize = sc->sc_sectorsize;
732 	md->md_mflags = (sc->sc_flags & G_MIRROR_DEVICE_FLAG_MASK);
733 	bzero(md->md_provider, sizeof(md->md_provider));
734 	if (disk == NULL) {
735 		md->md_did = arc4random();
736 		md->md_priority = 0;
737 		md->md_syncid = 0;
738 		md->md_dflags = 0;
739 		md->md_sync_offset = 0;
740 		md->md_provsize = 0;
741 	} else {
742 		md->md_did = disk->d_id;
743 		md->md_priority = disk->d_priority;
744 		md->md_syncid = disk->d_sync.ds_syncid;
745 		md->md_dflags = (disk->d_flags & G_MIRROR_DISK_FLAG_MASK);
746 		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
747 			md->md_sync_offset = disk->d_sync.ds_offset_done;
748 		else
749 			md->md_sync_offset = 0;
750 		if ((disk->d_flags & G_MIRROR_DISK_FLAG_HARDCODED) != 0) {
751 			strlcpy(md->md_provider,
752 			    disk->d_consumer->provider->name,
753 			    sizeof(md->md_provider));
754 		}
755 		md->md_provsize = disk->d_consumer->provider->mediasize;
756 	}
757 }
758 
759 void
760 g_mirror_update_metadata(struct g_mirror_disk *disk)
761 {
762 	struct g_mirror_softc *sc;
763 	struct g_mirror_metadata md;
764 	int error;
765 
766 	g_topology_assert_not();
767 	sc = disk->d_softc;
768 	sx_assert(&sc->sc_lock, SX_LOCKED);
769 
770 	if (sc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
771 		return;
772 	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_WIPE) == 0)
773 		g_mirror_fill_metadata(sc, disk, &md);
774 	error = g_mirror_write_metadata(disk, &md);
775 	if (error == 0) {
776 		G_MIRROR_DEBUG(2, "Metadata on %s updated.",
777 		    g_mirror_get_diskname(disk));
778 	} else {
779 		G_MIRROR_DEBUG(0,
780 		    "Cannot update metadata on disk %s (error=%d).",
781 		    g_mirror_get_diskname(disk), error);
782 	}
783 }
784 
785 static void
786 g_mirror_bump_syncid(struct g_mirror_softc *sc)
787 {
788 	struct g_mirror_disk *disk;
789 
790 	g_topology_assert_not();
791 	sx_assert(&sc->sc_lock, SX_XLOCKED);
792 	KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
793 	    ("%s called with no active disks (device=%s).", __func__,
794 	    sc->sc_name));
795 
796 	sc->sc_syncid++;
797 	G_MIRROR_DEBUG(1, "Device %s: syncid bumped to %u.", sc->sc_name,
798 	    sc->sc_syncid);
799 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
800 		if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
801 		    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
802 			disk->d_sync.ds_syncid = sc->sc_syncid;
803 			g_mirror_update_metadata(disk);
804 		}
805 	}
806 }
807 
808 static void
809 g_mirror_bump_genid(struct g_mirror_softc *sc)
810 {
811 	struct g_mirror_disk *disk;
812 
813 	g_topology_assert_not();
814 	sx_assert(&sc->sc_lock, SX_XLOCKED);
815 	KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
816 	    ("%s called with no active disks (device=%s).", __func__,
817 	    sc->sc_name));
818 
819 	sc->sc_genid++;
820 	G_MIRROR_DEBUG(1, "Device %s: genid bumped to %u.", sc->sc_name,
821 	    sc->sc_genid);
822 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
823 		if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
824 		    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
825 			disk->d_genid = sc->sc_genid;
826 			g_mirror_update_metadata(disk);
827 		}
828 	}
829 }
830 
831 static int
832 g_mirror_idle(struct g_mirror_softc *sc, int acw)
833 {
834 	struct g_mirror_disk *disk;
835 	int timeout;
836 
837 	g_topology_assert_not();
838 	sx_assert(&sc->sc_lock, SX_XLOCKED);
839 
840 	if (sc->sc_provider == NULL)
841 		return (0);
842 	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
843 		return (0);
844 	if (sc->sc_idle)
845 		return (0);
846 	if (sc->sc_writes > 0)
847 		return (0);
848 	if (acw > 0 || (acw == -1 && sc->sc_provider->acw > 0)) {
849 		timeout = g_mirror_idletime - (time_uptime - sc->sc_last_write);
850 		if (!g_mirror_shutdown && timeout > 0)
851 			return (timeout);
852 	}
853 	sc->sc_idle = 1;
854 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
855 		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
856 			continue;
857 		G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as clean.",
858 		    g_mirror_get_diskname(disk), sc->sc_name);
859 		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
860 		g_mirror_update_metadata(disk);
861 	}
862 	return (0);
863 }
864 
865 static void
866 g_mirror_unidle(struct g_mirror_softc *sc)
867 {
868 	struct g_mirror_disk *disk;
869 
870 	g_topology_assert_not();
871 	sx_assert(&sc->sc_lock, SX_XLOCKED);
872 
873 	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
874 		return;
875 	sc->sc_idle = 0;
876 	sc->sc_last_write = time_uptime;
877 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
878 		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
879 			continue;
880 		G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as dirty.",
881 		    g_mirror_get_diskname(disk), sc->sc_name);
882 		disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
883 		g_mirror_update_metadata(disk);
884 	}
885 }
886 
887 static void
888 g_mirror_flush_done(struct bio *bp)
889 {
890 	struct g_mirror_softc *sc;
891 	struct bio *pbp;
892 
893 	pbp = bp->bio_parent;
894 	sc = pbp->bio_to->private;
895 	mtx_lock(&sc->sc_done_mtx);
896 	if (pbp->bio_error == 0)
897 		pbp->bio_error = bp->bio_error;
898 	pbp->bio_completed += bp->bio_completed;
899 	pbp->bio_inbed++;
900 	if (pbp->bio_children == pbp->bio_inbed) {
901 		mtx_unlock(&sc->sc_done_mtx);
902 		g_io_deliver(pbp, pbp->bio_error);
903 	} else
904 		mtx_unlock(&sc->sc_done_mtx);
905 	g_destroy_bio(bp);
906 }
907 
908 static void
909 g_mirror_done(struct bio *bp)
910 {
911 	struct g_mirror_softc *sc;
912 
913 	sc = bp->bio_from->geom->softc;
914 	bp->bio_cflags = G_MIRROR_BIO_FLAG_REGULAR;
915 	mtx_lock(&sc->sc_queue_mtx);
916 	bioq_insert_tail(&sc->sc_queue, bp);
917 	mtx_unlock(&sc->sc_queue_mtx);
918 	wakeup(sc);
919 }
920 
921 static void
922 g_mirror_regular_request(struct bio *bp)
923 {
924 	struct g_mirror_softc *sc;
925 	struct g_mirror_disk *disk;
926 	struct bio *pbp;
927 
928 	g_topology_assert_not();
929 
930 	pbp = bp->bio_parent;
931 	sc = pbp->bio_to->private;
932 	bp->bio_from->index--;
933 	if (bp->bio_cmd == BIO_WRITE)
934 		sc->sc_writes--;
935 	disk = bp->bio_from->private;
936 	if (disk == NULL) {
937 		g_topology_lock();
938 		g_mirror_kill_consumer(sc, bp->bio_from);
939 		g_topology_unlock();
940 	}
941 
942 	if (bp->bio_cmd == BIO_READ)
943 		KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_read,
944 		    bp->bio_error);
945 	else if (bp->bio_cmd == BIO_WRITE)
946 		KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_write,
947 		    bp->bio_error);
948 
949 	pbp->bio_inbed++;
950 	KASSERT(pbp->bio_inbed <= pbp->bio_children,
951 	    ("bio_inbed (%u) is bigger than bio_children (%u).", pbp->bio_inbed,
952 	    pbp->bio_children));
953 	if (bp->bio_error == 0 && pbp->bio_error == 0) {
954 		G_MIRROR_LOGREQ(3, bp, "Request delivered.");
955 		g_destroy_bio(bp);
956 		if (pbp->bio_children == pbp->bio_inbed) {
957 			G_MIRROR_LOGREQ(3, pbp, "Request delivered.");
958 			pbp->bio_completed = pbp->bio_length;
959 			if (pbp->bio_cmd == BIO_WRITE ||
960 			    pbp->bio_cmd == BIO_DELETE) {
961 				bioq_remove(&sc->sc_inflight, pbp);
962 				/* Release delayed sync requests if possible. */
963 				g_mirror_sync_release(sc);
964 			}
965 			g_io_deliver(pbp, pbp->bio_error);
966 		}
967 		return;
968 	} else if (bp->bio_error != 0) {
969 		if (pbp->bio_error == 0)
970 			pbp->bio_error = bp->bio_error;
971 		if (disk != NULL) {
972 			if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
973 				disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
974 				G_MIRROR_LOGREQ(0, bp,
975 				    "Request failed (error=%d).",
976 				    bp->bio_error);
977 			} else {
978 				G_MIRROR_LOGREQ(1, bp,
979 				    "Request failed (error=%d).",
980 				    bp->bio_error);
981 			}
982 			if (g_mirror_disconnect_on_failure &&
983 			    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1)
984 			{
985 				if (bp->bio_error == ENXIO &&
986 				    bp->bio_cmd == BIO_READ)
987 					sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
988 				else if (bp->bio_error == ENXIO)
989 					sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID_NOW;
990 				else
991 					sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
992 				g_mirror_event_send(disk,
993 				    G_MIRROR_DISK_STATE_DISCONNECTED,
994 				    G_MIRROR_EVENT_DONTWAIT);
995 			}
996 		}
997 		switch (pbp->bio_cmd) {
998 		case BIO_DELETE:
999 		case BIO_WRITE:
1000 			pbp->bio_inbed--;
1001 			pbp->bio_children--;
1002 			break;
1003 		}
1004 	}
1005 	g_destroy_bio(bp);
1006 
1007 	switch (pbp->bio_cmd) {
1008 	case BIO_READ:
1009 		if (pbp->bio_inbed < pbp->bio_children)
1010 			break;
1011 		if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 1)
1012 			g_io_deliver(pbp, pbp->bio_error);
1013 		else {
1014 			pbp->bio_error = 0;
1015 			mtx_lock(&sc->sc_queue_mtx);
1016 			bioq_insert_tail(&sc->sc_queue, pbp);
1017 			mtx_unlock(&sc->sc_queue_mtx);
1018 			G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
1019 			wakeup(sc);
1020 		}
1021 		break;
1022 	case BIO_DELETE:
1023 	case BIO_WRITE:
1024 		if (pbp->bio_children == 0) {
1025 			/*
1026 			 * All requests failed.
1027 			 */
1028 		} else if (pbp->bio_inbed < pbp->bio_children) {
1029 			/* Do nothing. */
1030 			break;
1031 		} else if (pbp->bio_children == pbp->bio_inbed) {
1032 			/* Some requests succeeded. */
1033 			pbp->bio_error = 0;
1034 			pbp->bio_completed = pbp->bio_length;
1035 		}
1036 		bioq_remove(&sc->sc_inflight, pbp);
1037 		/* Release delayed sync requests if possible. */
1038 		g_mirror_sync_release(sc);
1039 		g_io_deliver(pbp, pbp->bio_error);
1040 		break;
1041 	default:
1042 		KASSERT(1 == 0, ("Invalid request: %u.", pbp->bio_cmd));
1043 		break;
1044 	}
1045 }
1046 
1047 static void
1048 g_mirror_sync_done(struct bio *bp)
1049 {
1050 	struct g_mirror_softc *sc;
1051 
1052 	G_MIRROR_LOGREQ(3, bp, "Synchronization request delivered.");
1053 	sc = bp->bio_from->geom->softc;
1054 	bp->bio_cflags = G_MIRROR_BIO_FLAG_SYNC;
1055 	mtx_lock(&sc->sc_queue_mtx);
1056 	bioq_insert_tail(&sc->sc_queue, bp);
1057 	mtx_unlock(&sc->sc_queue_mtx);
1058 	wakeup(sc);
1059 }
1060 
1061 static void
1062 g_mirror_candelete(struct bio *bp)
1063 {
1064 	struct g_mirror_softc *sc;
1065 	struct g_mirror_disk *disk;
1066 	int *val;
1067 
1068 	sc = bp->bio_to->private;
1069 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1070 		if (disk->d_flags & G_MIRROR_DISK_FLAG_CANDELETE)
1071 			break;
1072 	}
1073 	val = (int *)bp->bio_data;
1074 	*val = (disk != NULL);
1075 	g_io_deliver(bp, 0);
1076 }
1077 
1078 static void
1079 g_mirror_kernel_dump(struct bio *bp)
1080 {
1081 	struct g_mirror_softc *sc;
1082 	struct g_mirror_disk *disk;
1083 	struct bio *cbp;
1084 	struct g_kerneldump *gkd;
1085 
1086 	/*
1087 	 * We configure dumping to the first component, because this component
1088 	 * will be used for reading with 'prefer' balance algorithm.
1089 	 * If the component with the highest priority is currently disconnected
1090 	 * we will not be able to read the dump after the reboot if it will be
1091 	 * connected and synchronized later. Can we do something better?
1092 	 */
1093 	sc = bp->bio_to->private;
1094 	disk = LIST_FIRST(&sc->sc_disks);
1095 
1096 	gkd = (struct g_kerneldump *)bp->bio_data;
1097 	if (gkd->length > bp->bio_to->mediasize)
1098 		gkd->length = bp->bio_to->mediasize;
1099 	cbp = g_clone_bio(bp);
1100 	if (cbp == NULL) {
1101 		g_io_deliver(bp, ENOMEM);
1102 		return;
1103 	}
1104 	cbp->bio_done = g_std_done;
1105 	g_io_request(cbp, disk->d_consumer);
1106 	G_MIRROR_DEBUG(1, "Kernel dump will go to %s.",
1107 	    g_mirror_get_diskname(disk));
1108 }
1109 
1110 static void
1111 g_mirror_flush(struct g_mirror_softc *sc, struct bio *bp)
1112 {
1113 	struct bio_queue_head queue;
1114 	struct g_mirror_disk *disk;
1115 	struct g_consumer *cp;
1116 	struct bio *cbp;
1117 
1118 	bioq_init(&queue);
1119 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1120 		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1121 			continue;
1122 		cbp = g_clone_bio(bp);
1123 		if (cbp == NULL) {
1124 			while ((cbp = bioq_takefirst(&queue)) != NULL)
1125 				g_destroy_bio(cbp);
1126 			if (bp->bio_error == 0)
1127 				bp->bio_error = ENOMEM;
1128 			g_io_deliver(bp, bp->bio_error);
1129 			return;
1130 		}
1131 		bioq_insert_tail(&queue, cbp);
1132 		cbp->bio_done = g_mirror_flush_done;
1133 		cbp->bio_caller1 = disk;
1134 		cbp->bio_to = disk->d_consumer->provider;
1135 	}
1136 	while ((cbp = bioq_takefirst(&queue)) != NULL) {
1137 		G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1138 		disk = cbp->bio_caller1;
1139 		cbp->bio_caller1 = NULL;
1140 		cp = disk->d_consumer;
1141 		KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1142 		    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1143 		    cp->acr, cp->acw, cp->ace));
1144 		g_io_request(cbp, disk->d_consumer);
1145 	}
1146 }
1147 
1148 static void
1149 g_mirror_start(struct bio *bp)
1150 {
1151 	struct g_mirror_softc *sc;
1152 
1153 	sc = bp->bio_to->private;
1154 	/*
1155 	 * If sc == NULL or there are no valid disks, provider's error
1156 	 * should be set and g_mirror_start() should not be called at all.
1157 	 */
1158 	KASSERT(sc != NULL && sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
1159 	    ("Provider's error should be set (error=%d)(mirror=%s).",
1160 	    bp->bio_to->error, bp->bio_to->name));
1161 	G_MIRROR_LOGREQ(3, bp, "Request received.");
1162 
1163 	switch (bp->bio_cmd) {
1164 	case BIO_READ:
1165 	case BIO_WRITE:
1166 	case BIO_DELETE:
1167 		break;
1168 	case BIO_FLUSH:
1169 		g_mirror_flush(sc, bp);
1170 		return;
1171 	case BIO_GETATTR:
1172 		if (!strcmp(bp->bio_attribute, "GEOM::candelete")) {
1173 			g_mirror_candelete(bp);
1174 			return;
1175 		} else if (strcmp("GEOM::kerneldump", bp->bio_attribute) == 0) {
1176 			g_mirror_kernel_dump(bp);
1177 			return;
1178 		}
1179 		/* FALLTHROUGH */
1180 	default:
1181 		g_io_deliver(bp, EOPNOTSUPP);
1182 		return;
1183 	}
1184 	mtx_lock(&sc->sc_queue_mtx);
1185 	if (bp->bio_to->error != 0) {
1186 		mtx_unlock(&sc->sc_queue_mtx);
1187 		g_io_deliver(bp, bp->bio_to->error);
1188 		return;
1189 	}
1190 	bioq_insert_tail(&sc->sc_queue, bp);
1191 	mtx_unlock(&sc->sc_queue_mtx);
1192 	G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
1193 	wakeup(sc);
1194 }
1195 
1196 /*
1197  * Return TRUE if the given request is colliding with a in-progress
1198  * synchronization request.
1199  */
1200 static int
1201 g_mirror_sync_collision(struct g_mirror_softc *sc, struct bio *bp)
1202 {
1203 	struct g_mirror_disk *disk;
1204 	struct bio *sbp;
1205 	off_t rstart, rend, sstart, send;
1206 	u_int i;
1207 
1208 	if (sc->sc_sync.ds_ndisks == 0)
1209 		return (0);
1210 	rstart = bp->bio_offset;
1211 	rend = bp->bio_offset + bp->bio_length;
1212 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1213 		if (disk->d_state != G_MIRROR_DISK_STATE_SYNCHRONIZING)
1214 			continue;
1215 		for (i = 0; i < g_mirror_syncreqs; i++) {
1216 			sbp = disk->d_sync.ds_bios[i];
1217 			if (sbp == NULL)
1218 				continue;
1219 			sstart = sbp->bio_offset;
1220 			send = sbp->bio_offset + sbp->bio_length;
1221 			if (rend > sstart && rstart < send)
1222 				return (1);
1223 		}
1224 	}
1225 	return (0);
1226 }
1227 
1228 /*
1229  * Return TRUE if the given sync request is colliding with a in-progress regular
1230  * request.
1231  */
1232 static int
1233 g_mirror_regular_collision(struct g_mirror_softc *sc, struct bio *sbp)
1234 {
1235 	off_t rstart, rend, sstart, send;
1236 	struct bio *bp;
1237 
1238 	if (sc->sc_sync.ds_ndisks == 0)
1239 		return (0);
1240 	sstart = sbp->bio_offset;
1241 	send = sbp->bio_offset + sbp->bio_length;
1242 	TAILQ_FOREACH(bp, &sc->sc_inflight.queue, bio_queue) {
1243 		rstart = bp->bio_offset;
1244 		rend = bp->bio_offset + bp->bio_length;
1245 		if (rend > sstart && rstart < send)
1246 			return (1);
1247 	}
1248 	return (0);
1249 }
1250 
1251 /*
1252  * Puts request onto delayed queue.
1253  */
1254 static void
1255 g_mirror_regular_delay(struct g_mirror_softc *sc, struct bio *bp)
1256 {
1257 
1258 	G_MIRROR_LOGREQ(2, bp, "Delaying request.");
1259 	bioq_insert_head(&sc->sc_regular_delayed, bp);
1260 }
1261 
1262 /*
1263  * Puts synchronization request onto delayed queue.
1264  */
1265 static void
1266 g_mirror_sync_delay(struct g_mirror_softc *sc, struct bio *bp)
1267 {
1268 
1269 	G_MIRROR_LOGREQ(2, bp, "Delaying synchronization request.");
1270 	bioq_insert_tail(&sc->sc_sync_delayed, bp);
1271 }
1272 
1273 /*
1274  * Releases delayed regular requests which don't collide anymore with sync
1275  * requests.
1276  */
1277 static void
1278 g_mirror_regular_release(struct g_mirror_softc *sc)
1279 {
1280 	struct bio *bp, *bp2;
1281 
1282 	TAILQ_FOREACH_SAFE(bp, &sc->sc_regular_delayed.queue, bio_queue, bp2) {
1283 		if (g_mirror_sync_collision(sc, bp))
1284 			continue;
1285 		bioq_remove(&sc->sc_regular_delayed, bp);
1286 		G_MIRROR_LOGREQ(2, bp, "Releasing delayed request (%p).", bp);
1287 		mtx_lock(&sc->sc_queue_mtx);
1288 		bioq_insert_head(&sc->sc_queue, bp);
1289 		mtx_unlock(&sc->sc_queue_mtx);
1290 	}
1291 }
1292 
1293 /*
1294  * Releases delayed sync requests which don't collide anymore with regular
1295  * requests.
1296  */
1297 static void
1298 g_mirror_sync_release(struct g_mirror_softc *sc)
1299 {
1300 	struct bio *bp, *bp2;
1301 
1302 	TAILQ_FOREACH_SAFE(bp, &sc->sc_sync_delayed.queue, bio_queue, bp2) {
1303 		if (g_mirror_regular_collision(sc, bp))
1304 			continue;
1305 		bioq_remove(&sc->sc_sync_delayed, bp);
1306 		G_MIRROR_LOGREQ(2, bp,
1307 		    "Releasing delayed synchronization request.");
1308 		g_io_request(bp, bp->bio_from);
1309 	}
1310 }
1311 
1312 /*
1313  * Free a synchronization request and clear its slot in the array.
1314  */
1315 static void
1316 g_mirror_sync_request_free(struct g_mirror_disk *disk, struct bio *bp)
1317 {
1318 	int idx;
1319 
1320 	if (disk != NULL && disk->d_sync.ds_bios != NULL) {
1321 		idx = (int)(uintptr_t)bp->bio_caller1;
1322 		KASSERT(disk->d_sync.ds_bios[idx] == bp,
1323 		    ("unexpected sync BIO at %p:%d", disk, idx));
1324 		disk->d_sync.ds_bios[idx] = NULL;
1325 	}
1326 	free(bp->bio_data, M_MIRROR);
1327 	g_destroy_bio(bp);
1328 }
1329 
1330 /*
1331  * Handle synchronization requests.
1332  * Every synchronization request is two-steps process: first, READ request is
1333  * send to active provider and then WRITE request (with read data) to the provider
1334  * being synchronized. When WRITE is finished, new synchronization request is
1335  * send.
1336  */
1337 static void
1338 g_mirror_sync_request(struct bio *bp)
1339 {
1340 	struct g_mirror_softc *sc;
1341 	struct g_mirror_disk *disk;
1342 	struct g_mirror_disk_sync *sync;
1343 
1344 	bp->bio_from->index--;
1345 	sc = bp->bio_from->geom->softc;
1346 	disk = bp->bio_from->private;
1347 	if (disk == NULL) {
1348 		sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
1349 		g_topology_lock();
1350 		g_mirror_kill_consumer(sc, bp->bio_from);
1351 		g_topology_unlock();
1352 		g_mirror_sync_request_free(NULL, bp);
1353 		sx_xlock(&sc->sc_lock);
1354 		return;
1355 	}
1356 
1357 	/*
1358 	 * Synchronization request.
1359 	 */
1360 	switch (bp->bio_cmd) {
1361 	case BIO_READ:
1362 	    {
1363 		struct g_consumer *cp;
1364 
1365 		KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_sync_request_read,
1366 		    bp->bio_error);
1367 
1368 		if (bp->bio_error != 0) {
1369 			G_MIRROR_LOGREQ(0, bp,
1370 			    "Synchronization request failed (error=%d).",
1371 			    bp->bio_error);
1372 			g_mirror_sync_request_free(disk, bp);
1373 			return;
1374 		}
1375 		G_MIRROR_LOGREQ(3, bp,
1376 		    "Synchronization request half-finished.");
1377 		bp->bio_cmd = BIO_WRITE;
1378 		bp->bio_cflags = 0;
1379 		cp = disk->d_consumer;
1380 		KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1381 		    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1382 		    cp->acr, cp->acw, cp->ace));
1383 		cp->index++;
1384 		g_io_request(bp, cp);
1385 		return;
1386 	    }
1387 	case BIO_WRITE:
1388 	    {
1389 		off_t offset;
1390 		void *data;
1391 		int i, idx;
1392 
1393 		KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_sync_request_write,
1394 		    bp->bio_error);
1395 
1396 		if (bp->bio_error != 0) {
1397 			G_MIRROR_LOGREQ(0, bp,
1398 			    "Synchronization request failed (error=%d).",
1399 			    bp->bio_error);
1400 			g_mirror_sync_request_free(disk, bp);
1401 			sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
1402 			g_mirror_event_send(disk,
1403 			    G_MIRROR_DISK_STATE_DISCONNECTED,
1404 			    G_MIRROR_EVENT_DONTWAIT);
1405 			return;
1406 		}
1407 		G_MIRROR_LOGREQ(3, bp, "Synchronization request finished.");
1408 		sync = &disk->d_sync;
1409 		if (sync->ds_offset >= sc->sc_mediasize ||
1410 		    sync->ds_consumer == NULL ||
1411 		    (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1412 			/* Don't send more synchronization requests. */
1413 			sync->ds_inflight--;
1414 			g_mirror_sync_request_free(disk, bp);
1415 			if (sync->ds_inflight > 0)
1416 				return;
1417 			if (sync->ds_consumer == NULL ||
1418 			    (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1419 				return;
1420 			}
1421 			/* Disk up-to-date, activate it. */
1422 			g_mirror_event_send(disk, G_MIRROR_DISK_STATE_ACTIVE,
1423 			    G_MIRROR_EVENT_DONTWAIT);
1424 			return;
1425 		}
1426 
1427 		/* Send next synchronization request. */
1428 		data = bp->bio_data;
1429 		idx = (int)(uintptr_t)bp->bio_caller1;
1430 		g_reset_bio(bp);
1431 		bp->bio_cmd = BIO_READ;
1432 		bp->bio_offset = sync->ds_offset;
1433 		bp->bio_length = MIN(MAXPHYS, sc->sc_mediasize - bp->bio_offset);
1434 		sync->ds_offset += bp->bio_length;
1435 		bp->bio_done = g_mirror_sync_done;
1436 		bp->bio_data = data;
1437 		bp->bio_from = sync->ds_consumer;
1438 		bp->bio_to = sc->sc_provider;
1439 		bp->bio_caller1 = (void *)(uintptr_t)idx;
1440 		G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
1441 		sync->ds_consumer->index++;
1442 		/*
1443 		 * Delay the request if it is colliding with a regular request.
1444 		 */
1445 		if (g_mirror_regular_collision(sc, bp))
1446 			g_mirror_sync_delay(sc, bp);
1447 		else
1448 			g_io_request(bp, sync->ds_consumer);
1449 
1450 		/* Release delayed requests if possible. */
1451 		g_mirror_regular_release(sc);
1452 
1453 		/* Find the smallest offset */
1454 		offset = sc->sc_mediasize;
1455 		for (i = 0; i < g_mirror_syncreqs; i++) {
1456 			bp = sync->ds_bios[i];
1457 			if (bp != NULL && bp->bio_offset < offset)
1458 				offset = bp->bio_offset;
1459 		}
1460 		if (sync->ds_offset_done + (MAXPHYS * 100) < offset) {
1461 			/* Update offset_done on every 100 blocks. */
1462 			sync->ds_offset_done = offset;
1463 			g_mirror_update_metadata(disk);
1464 		}
1465 		return;
1466 	    }
1467 	default:
1468 		KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
1469 		    bp->bio_cmd, sc->sc_name));
1470 		break;
1471 	}
1472 }
1473 
1474 static void
1475 g_mirror_request_prefer(struct g_mirror_softc *sc, struct bio *bp)
1476 {
1477 	struct g_mirror_disk *disk;
1478 	struct g_consumer *cp;
1479 	struct bio *cbp;
1480 
1481 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1482 		if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE)
1483 			break;
1484 	}
1485 	if (disk == NULL) {
1486 		if (bp->bio_error == 0)
1487 			bp->bio_error = ENXIO;
1488 		g_io_deliver(bp, bp->bio_error);
1489 		return;
1490 	}
1491 	cbp = g_clone_bio(bp);
1492 	if (cbp == NULL) {
1493 		if (bp->bio_error == 0)
1494 			bp->bio_error = ENOMEM;
1495 		g_io_deliver(bp, bp->bio_error);
1496 		return;
1497 	}
1498 	/*
1499 	 * Fill in the component buf structure.
1500 	 */
1501 	cp = disk->d_consumer;
1502 	cbp->bio_done = g_mirror_done;
1503 	cbp->bio_to = cp->provider;
1504 	G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1505 	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1506 	    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1507 	    cp->acw, cp->ace));
1508 	cp->index++;
1509 	g_io_request(cbp, cp);
1510 }
1511 
1512 static void
1513 g_mirror_request_round_robin(struct g_mirror_softc *sc, struct bio *bp)
1514 {
1515 	struct g_mirror_disk *disk;
1516 	struct g_consumer *cp;
1517 	struct bio *cbp;
1518 
1519 	disk = g_mirror_get_disk(sc);
1520 	if (disk == NULL) {
1521 		if (bp->bio_error == 0)
1522 			bp->bio_error = ENXIO;
1523 		g_io_deliver(bp, bp->bio_error);
1524 		return;
1525 	}
1526 	cbp = g_clone_bio(bp);
1527 	if (cbp == NULL) {
1528 		if (bp->bio_error == 0)
1529 			bp->bio_error = ENOMEM;
1530 		g_io_deliver(bp, bp->bio_error);
1531 		return;
1532 	}
1533 	/*
1534 	 * Fill in the component buf structure.
1535 	 */
1536 	cp = disk->d_consumer;
1537 	cbp->bio_done = g_mirror_done;
1538 	cbp->bio_to = cp->provider;
1539 	G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1540 	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1541 	    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1542 	    cp->acw, cp->ace));
1543 	cp->index++;
1544 	g_io_request(cbp, cp);
1545 }
1546 
1547 #define TRACK_SIZE  (1 * 1024 * 1024)
1548 #define LOAD_SCALE	256
1549 #define ABS(x)		(((x) >= 0) ? (x) : (-(x)))
1550 
1551 static void
1552 g_mirror_request_load(struct g_mirror_softc *sc, struct bio *bp)
1553 {
1554 	struct g_mirror_disk *disk, *dp;
1555 	struct g_consumer *cp;
1556 	struct bio *cbp;
1557 	int prio, best;
1558 
1559 	/* Find a disk with the smallest load. */
1560 	disk = NULL;
1561 	best = INT_MAX;
1562 	LIST_FOREACH(dp, &sc->sc_disks, d_next) {
1563 		if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1564 			continue;
1565 		prio = dp->load;
1566 		/* If disk head is precisely in position - highly prefer it. */
1567 		if (dp->d_last_offset == bp->bio_offset)
1568 			prio -= 2 * LOAD_SCALE;
1569 		else
1570 		/* If disk head is close to position - prefer it. */
1571 		if (ABS(dp->d_last_offset - bp->bio_offset) < TRACK_SIZE)
1572 			prio -= 1 * LOAD_SCALE;
1573 		if (prio <= best) {
1574 			disk = dp;
1575 			best = prio;
1576 		}
1577 	}
1578 	KASSERT(disk != NULL, ("NULL disk for %s.", sc->sc_name));
1579 	cbp = g_clone_bio(bp);
1580 	if (cbp == NULL) {
1581 		if (bp->bio_error == 0)
1582 			bp->bio_error = ENOMEM;
1583 		g_io_deliver(bp, bp->bio_error);
1584 		return;
1585 	}
1586 	/*
1587 	 * Fill in the component buf structure.
1588 	 */
1589 	cp = disk->d_consumer;
1590 	cbp->bio_done = g_mirror_done;
1591 	cbp->bio_to = cp->provider;
1592 	G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1593 	KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1594 	    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1595 	    cp->acw, cp->ace));
1596 	cp->index++;
1597 	/* Remember last head position */
1598 	disk->d_last_offset = bp->bio_offset + bp->bio_length;
1599 	/* Update loads. */
1600 	LIST_FOREACH(dp, &sc->sc_disks, d_next) {
1601 		dp->load = (dp->d_consumer->index * LOAD_SCALE +
1602 		    dp->load * 7) / 8;
1603 	}
1604 	g_io_request(cbp, cp);
1605 }
1606 
1607 static void
1608 g_mirror_request_split(struct g_mirror_softc *sc, struct bio *bp)
1609 {
1610 	struct bio_queue_head queue;
1611 	struct g_mirror_disk *disk;
1612 	struct g_consumer *cp;
1613 	struct bio *cbp;
1614 	off_t left, mod, offset, slice;
1615 	u_char *data;
1616 	u_int ndisks;
1617 
1618 	if (bp->bio_length <= sc->sc_slice) {
1619 		g_mirror_request_round_robin(sc, bp);
1620 		return;
1621 	}
1622 	ndisks = g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE);
1623 	slice = bp->bio_length / ndisks;
1624 	mod = slice % sc->sc_provider->sectorsize;
1625 	if (mod != 0)
1626 		slice += sc->sc_provider->sectorsize - mod;
1627 	/*
1628 	 * Allocate all bios before sending any request, so we can
1629 	 * return ENOMEM in nice and clean way.
1630 	 */
1631 	left = bp->bio_length;
1632 	offset = bp->bio_offset;
1633 	data = bp->bio_data;
1634 	bioq_init(&queue);
1635 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1636 		if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1637 			continue;
1638 		cbp = g_clone_bio(bp);
1639 		if (cbp == NULL) {
1640 			while ((cbp = bioq_takefirst(&queue)) != NULL)
1641 				g_destroy_bio(cbp);
1642 			if (bp->bio_error == 0)
1643 				bp->bio_error = ENOMEM;
1644 			g_io_deliver(bp, bp->bio_error);
1645 			return;
1646 		}
1647 		bioq_insert_tail(&queue, cbp);
1648 		cbp->bio_done = g_mirror_done;
1649 		cbp->bio_caller1 = disk;
1650 		cbp->bio_to = disk->d_consumer->provider;
1651 		cbp->bio_offset = offset;
1652 		cbp->bio_data = data;
1653 		cbp->bio_length = MIN(left, slice);
1654 		left -= cbp->bio_length;
1655 		if (left == 0)
1656 			break;
1657 		offset += cbp->bio_length;
1658 		data += cbp->bio_length;
1659 	}
1660 	while ((cbp = bioq_takefirst(&queue)) != NULL) {
1661 		G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1662 		disk = cbp->bio_caller1;
1663 		cbp->bio_caller1 = NULL;
1664 		cp = disk->d_consumer;
1665 		KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1666 		    ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1667 		    cp->acr, cp->acw, cp->ace));
1668 		disk->d_consumer->index++;
1669 		g_io_request(cbp, disk->d_consumer);
1670 	}
1671 }
1672 
1673 static void
1674 g_mirror_register_request(struct bio *bp)
1675 {
1676 	struct g_mirror_softc *sc;
1677 
1678 	sc = bp->bio_to->private;
1679 	switch (bp->bio_cmd) {
1680 	case BIO_READ:
1681 		switch (sc->sc_balance) {
1682 		case G_MIRROR_BALANCE_LOAD:
1683 			g_mirror_request_load(sc, bp);
1684 			break;
1685 		case G_MIRROR_BALANCE_PREFER:
1686 			g_mirror_request_prefer(sc, bp);
1687 			break;
1688 		case G_MIRROR_BALANCE_ROUND_ROBIN:
1689 			g_mirror_request_round_robin(sc, bp);
1690 			break;
1691 		case G_MIRROR_BALANCE_SPLIT:
1692 			g_mirror_request_split(sc, bp);
1693 			break;
1694 		}
1695 		return;
1696 	case BIO_WRITE:
1697 	case BIO_DELETE:
1698 	    {
1699 		struct g_mirror_disk *disk;
1700 		struct g_mirror_disk_sync *sync;
1701 		struct bio_queue_head queue;
1702 		struct g_consumer *cp;
1703 		struct bio *cbp;
1704 
1705 		/*
1706 		 * Delay the request if it is colliding with a synchronization
1707 		 * request.
1708 		 */
1709 		if (g_mirror_sync_collision(sc, bp)) {
1710 			g_mirror_regular_delay(sc, bp);
1711 			return;
1712 		}
1713 
1714 		if (sc->sc_idle)
1715 			g_mirror_unidle(sc);
1716 		else
1717 			sc->sc_last_write = time_uptime;
1718 
1719 		/*
1720 		 * Bump syncid on first write.
1721 		 */
1722 		if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0) {
1723 			sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
1724 			g_mirror_bump_syncid(sc);
1725 		}
1726 
1727 		/*
1728 		 * Allocate all bios before sending any request, so we can
1729 		 * return ENOMEM in nice and clean way.
1730 		 */
1731 		bioq_init(&queue);
1732 		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1733 			sync = &disk->d_sync;
1734 			switch (disk->d_state) {
1735 			case G_MIRROR_DISK_STATE_ACTIVE:
1736 				break;
1737 			case G_MIRROR_DISK_STATE_SYNCHRONIZING:
1738 				if (bp->bio_offset >= sync->ds_offset)
1739 					continue;
1740 				break;
1741 			default:
1742 				continue;
1743 			}
1744 			if (bp->bio_cmd == BIO_DELETE &&
1745 			    (disk->d_flags & G_MIRROR_DISK_FLAG_CANDELETE) == 0)
1746 				continue;
1747 			cbp = g_clone_bio(bp);
1748 			if (cbp == NULL) {
1749 				while ((cbp = bioq_takefirst(&queue)) != NULL)
1750 					g_destroy_bio(cbp);
1751 				if (bp->bio_error == 0)
1752 					bp->bio_error = ENOMEM;
1753 				g_io_deliver(bp, bp->bio_error);
1754 				return;
1755 			}
1756 			bioq_insert_tail(&queue, cbp);
1757 			cbp->bio_done = g_mirror_done;
1758 			cp = disk->d_consumer;
1759 			cbp->bio_caller1 = cp;
1760 			cbp->bio_to = cp->provider;
1761 			KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1762 			    ("Consumer %s not opened (r%dw%de%d).",
1763 			    cp->provider->name, cp->acr, cp->acw, cp->ace));
1764 		}
1765 		if (bioq_first(&queue) == NULL) {
1766 			g_io_deliver(bp, EOPNOTSUPP);
1767 			return;
1768 		}
1769 		while ((cbp = bioq_takefirst(&queue)) != NULL) {
1770 			G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1771 			cp = cbp->bio_caller1;
1772 			cbp->bio_caller1 = NULL;
1773 			cp->index++;
1774 			sc->sc_writes++;
1775 			g_io_request(cbp, cp);
1776 		}
1777 		/*
1778 		 * Put request onto inflight queue, so we can check if new
1779 		 * synchronization requests don't collide with it.
1780 		 */
1781 		bioq_insert_tail(&sc->sc_inflight, bp);
1782 		return;
1783 	    }
1784 	default:
1785 		KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
1786 		    bp->bio_cmd, sc->sc_name));
1787 		break;
1788 	}
1789 }
1790 
1791 static int
1792 g_mirror_can_destroy(struct g_mirror_softc *sc)
1793 {
1794 	struct g_geom *gp;
1795 	struct g_consumer *cp;
1796 
1797 	g_topology_assert();
1798 	gp = sc->sc_geom;
1799 	if (gp->softc == NULL)
1800 		return (1);
1801 	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_TASTING) != 0)
1802 		return (0);
1803 	LIST_FOREACH(cp, &gp->consumer, consumer) {
1804 		if (g_mirror_is_busy(sc, cp))
1805 			return (0);
1806 	}
1807 	gp = sc->sc_sync.ds_geom;
1808 	LIST_FOREACH(cp, &gp->consumer, consumer) {
1809 		if (g_mirror_is_busy(sc, cp))
1810 			return (0);
1811 	}
1812 	G_MIRROR_DEBUG(2, "No I/O requests for %s, it can be destroyed.",
1813 	    sc->sc_name);
1814 	return (1);
1815 }
1816 
1817 static int
1818 g_mirror_try_destroy(struct g_mirror_softc *sc)
1819 {
1820 
1821 	if (sc->sc_rootmount != NULL) {
1822 		G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
1823 		    sc->sc_rootmount);
1824 		root_mount_rel(sc->sc_rootmount);
1825 		sc->sc_rootmount = NULL;
1826 	}
1827 	g_topology_lock();
1828 	if (!g_mirror_can_destroy(sc)) {
1829 		g_topology_unlock();
1830 		return (0);
1831 	}
1832 	sc->sc_geom->softc = NULL;
1833 	sc->sc_sync.ds_geom->softc = NULL;
1834 	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DRAIN) != 0) {
1835 		g_topology_unlock();
1836 		G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1837 		    &sc->sc_worker);
1838 		/* Unlock sc_lock here, as it can be destroyed after wakeup. */
1839 		sx_xunlock(&sc->sc_lock);
1840 		wakeup(&sc->sc_worker);
1841 		sc->sc_worker = NULL;
1842 	} else {
1843 		g_topology_unlock();
1844 		g_mirror_destroy_device(sc);
1845 	}
1846 	return (1);
1847 }
1848 
1849 /*
1850  * Worker thread.
1851  */
1852 static void
1853 g_mirror_worker(void *arg)
1854 {
1855 	struct g_mirror_softc *sc;
1856 	struct g_mirror_event *ep;
1857 	struct bio *bp;
1858 	int timeout;
1859 
1860 	sc = arg;
1861 	thread_lock(curthread);
1862 	sched_prio(curthread, PRIBIO);
1863 	thread_unlock(curthread);
1864 
1865 	sx_xlock(&sc->sc_lock);
1866 	for (;;) {
1867 		G_MIRROR_DEBUG(5, "%s: Let's see...", __func__);
1868 		/*
1869 		 * First take a look at events.
1870 		 * This is important to handle events before any I/O requests.
1871 		 */
1872 		ep = g_mirror_event_get(sc);
1873 		if (ep != NULL) {
1874 			g_mirror_event_remove(sc, ep);
1875 			if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0) {
1876 				/* Update only device status. */
1877 				G_MIRROR_DEBUG(3,
1878 				    "Running event for device %s.",
1879 				    sc->sc_name);
1880 				ep->e_error = 0;
1881 				g_mirror_update_device(sc, true);
1882 			} else {
1883 				/* Update disk status. */
1884 				G_MIRROR_DEBUG(3, "Running event for disk %s.",
1885 				     g_mirror_get_diskname(ep->e_disk));
1886 				ep->e_error = g_mirror_update_disk(ep->e_disk,
1887 				    ep->e_state);
1888 				if (ep->e_error == 0)
1889 					g_mirror_update_device(sc, false);
1890 			}
1891 			if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0) {
1892 				KASSERT(ep->e_error == 0,
1893 				    ("Error cannot be handled."));
1894 				g_mirror_event_free(ep);
1895 			} else {
1896 				ep->e_flags |= G_MIRROR_EVENT_DONE;
1897 				G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1898 				    ep);
1899 				mtx_lock(&sc->sc_events_mtx);
1900 				wakeup(ep);
1901 				mtx_unlock(&sc->sc_events_mtx);
1902 			}
1903 			if ((sc->sc_flags &
1904 			    G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1905 				if (g_mirror_try_destroy(sc)) {
1906 					curthread->td_pflags &= ~TDP_GEOM;
1907 					G_MIRROR_DEBUG(1, "Thread exiting.");
1908 					kproc_exit(0);
1909 				}
1910 			}
1911 			G_MIRROR_DEBUG(5, "%s: I'm here 1.", __func__);
1912 			continue;
1913 		}
1914 		/*
1915 		 * Check if we can mark array as CLEAN and if we can't take
1916 		 * how much seconds should we wait.
1917 		 */
1918 		timeout = g_mirror_idle(sc, -1);
1919 		/*
1920 		 * Now I/O requests.
1921 		 */
1922 		/* Get first request from the queue. */
1923 		mtx_lock(&sc->sc_queue_mtx);
1924 		bp = bioq_takefirst(&sc->sc_queue);
1925 		if (bp == NULL) {
1926 			if ((sc->sc_flags &
1927 			    G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1928 				mtx_unlock(&sc->sc_queue_mtx);
1929 				if (g_mirror_try_destroy(sc)) {
1930 					curthread->td_pflags &= ~TDP_GEOM;
1931 					G_MIRROR_DEBUG(1, "Thread exiting.");
1932 					kproc_exit(0);
1933 				}
1934 				mtx_lock(&sc->sc_queue_mtx);
1935 				if (bioq_first(&sc->sc_queue) != NULL) {
1936 					mtx_unlock(&sc->sc_queue_mtx);
1937 					continue;
1938 				}
1939 			}
1940 			sx_xunlock(&sc->sc_lock);
1941 			/*
1942 			 * XXX: We can miss an event here, because an event
1943 			 *      can be added without sx-device-lock and without
1944 			 *      mtx-queue-lock. Maybe I should just stop using
1945 			 *      dedicated mutex for events synchronization and
1946 			 *      stick with the queue lock?
1947 			 *      The event will hang here until next I/O request
1948 			 *      or next event is received.
1949 			 */
1950 			MSLEEP(sc, &sc->sc_queue_mtx, PRIBIO | PDROP, "m:w1",
1951 			    timeout * hz);
1952 			sx_xlock(&sc->sc_lock);
1953 			G_MIRROR_DEBUG(5, "%s: I'm here 4.", __func__);
1954 			continue;
1955 		}
1956 		mtx_unlock(&sc->sc_queue_mtx);
1957 
1958 		if (bp->bio_from->geom == sc->sc_sync.ds_geom &&
1959 		    (bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0) {
1960 			g_mirror_sync_request(bp);	/* READ */
1961 		} else if (bp->bio_to != sc->sc_provider) {
1962 			if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_REGULAR) != 0)
1963 				g_mirror_regular_request(bp);
1964 			else if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0)
1965 				g_mirror_sync_request(bp);	/* WRITE */
1966 			else {
1967 				KASSERT(0,
1968 				    ("Invalid request cflags=0x%hx to=%s.",
1969 				    bp->bio_cflags, bp->bio_to->name));
1970 			}
1971 		} else {
1972 			g_mirror_register_request(bp);
1973 		}
1974 		G_MIRROR_DEBUG(5, "%s: I'm here 9.", __func__);
1975 	}
1976 }
1977 
1978 static void
1979 g_mirror_update_idle(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
1980 {
1981 
1982 	sx_assert(&sc->sc_lock, SX_LOCKED);
1983 
1984 	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
1985 		return;
1986 	if (!sc->sc_idle && (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) == 0) {
1987 		G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as dirty.",
1988 		    g_mirror_get_diskname(disk), sc->sc_name);
1989 		disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
1990 	} else if (sc->sc_idle &&
1991 	    (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
1992 		G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as clean.",
1993 		    g_mirror_get_diskname(disk), sc->sc_name);
1994 		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
1995 	}
1996 }
1997 
1998 static void
1999 g_mirror_sync_start(struct g_mirror_disk *disk)
2000 {
2001 	struct g_mirror_softc *sc;
2002 	struct g_consumer *cp;
2003 	struct bio *bp;
2004 	int error, i;
2005 
2006 	g_topology_assert_not();
2007 	sc = disk->d_softc;
2008 	sx_assert(&sc->sc_lock, SX_LOCKED);
2009 
2010 	KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2011 	    ("Disk %s is not marked for synchronization.",
2012 	    g_mirror_get_diskname(disk)));
2013 	KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2014 	    ("Device not in RUNNING state (%s, %u).", sc->sc_name,
2015 	    sc->sc_state));
2016 
2017 	sx_xunlock(&sc->sc_lock);
2018 	g_topology_lock();
2019 	cp = g_new_consumer(sc->sc_sync.ds_geom);
2020 	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
2021 	error = g_attach(cp, sc->sc_provider);
2022 	KASSERT(error == 0,
2023 	    ("Cannot attach to %s (error=%d).", sc->sc_name, error));
2024 	error = g_access(cp, 1, 0, 0);
2025 	KASSERT(error == 0, ("Cannot open %s (error=%d).", sc->sc_name, error));
2026 	g_topology_unlock();
2027 	sx_xlock(&sc->sc_lock);
2028 
2029 	G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s.", sc->sc_name,
2030 	    g_mirror_get_diskname(disk));
2031 	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) == 0)
2032 		disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
2033 	KASSERT(disk->d_sync.ds_consumer == NULL,
2034 	    ("Sync consumer already exists (device=%s, disk=%s).",
2035 	    sc->sc_name, g_mirror_get_diskname(disk)));
2036 
2037 	disk->d_sync.ds_consumer = cp;
2038 	disk->d_sync.ds_consumer->private = disk;
2039 	disk->d_sync.ds_consumer->index = 0;
2040 
2041 	/*
2042 	 * Allocate memory for synchronization bios and initialize them.
2043 	 */
2044 	disk->d_sync.ds_bios = malloc(sizeof(struct bio *) * g_mirror_syncreqs,
2045 	    M_MIRROR, M_WAITOK);
2046 	for (i = 0; i < g_mirror_syncreqs; i++) {
2047 		bp = g_alloc_bio();
2048 		disk->d_sync.ds_bios[i] = bp;
2049 		bp->bio_parent = NULL;
2050 		bp->bio_cmd = BIO_READ;
2051 		bp->bio_data = malloc(MAXPHYS, M_MIRROR, M_WAITOK);
2052 		bp->bio_cflags = 0;
2053 		bp->bio_offset = disk->d_sync.ds_offset;
2054 		bp->bio_length = MIN(MAXPHYS, sc->sc_mediasize - bp->bio_offset);
2055 		disk->d_sync.ds_offset += bp->bio_length;
2056 		bp->bio_done = g_mirror_sync_done;
2057 		bp->bio_from = disk->d_sync.ds_consumer;
2058 		bp->bio_to = sc->sc_provider;
2059 		bp->bio_caller1 = (void *)(uintptr_t)i;
2060 	}
2061 
2062 	/* Increase the number of disks in SYNCHRONIZING state. */
2063 	sc->sc_sync.ds_ndisks++;
2064 	/* Set the number of in-flight synchronization requests. */
2065 	disk->d_sync.ds_inflight = g_mirror_syncreqs;
2066 
2067 	/*
2068 	 * Fire off first synchronization requests.
2069 	 */
2070 	for (i = 0; i < g_mirror_syncreqs; i++) {
2071 		bp = disk->d_sync.ds_bios[i];
2072 		G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
2073 		disk->d_sync.ds_consumer->index++;
2074 		/*
2075 		 * Delay the request if it is colliding with a regular request.
2076 		 */
2077 		if (g_mirror_regular_collision(sc, bp))
2078 			g_mirror_sync_delay(sc, bp);
2079 		else
2080 			g_io_request(bp, disk->d_sync.ds_consumer);
2081 	}
2082 }
2083 
2084 /*
2085  * Stop synchronization process.
2086  * type: 0 - synchronization finished
2087  *       1 - synchronization stopped
2088  */
2089 static void
2090 g_mirror_sync_stop(struct g_mirror_disk *disk, int type)
2091 {
2092 	struct g_mirror_softc *sc;
2093 	struct g_consumer *cp;
2094 
2095 	g_topology_assert_not();
2096 	sc = disk->d_softc;
2097 	sx_assert(&sc->sc_lock, SX_LOCKED);
2098 
2099 	KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2100 	    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2101 	    g_mirror_disk_state2str(disk->d_state)));
2102 	if (disk->d_sync.ds_consumer == NULL)
2103 		return;
2104 
2105 	if (type == 0) {
2106 		G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s finished.",
2107 		    sc->sc_name, g_mirror_get_diskname(disk));
2108 	} else /* if (type == 1) */ {
2109 		G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s stopped.",
2110 		    sc->sc_name, g_mirror_get_diskname(disk));
2111 	}
2112 	g_mirror_regular_release(sc);
2113 	free(disk->d_sync.ds_bios, M_MIRROR);
2114 	disk->d_sync.ds_bios = NULL;
2115 	cp = disk->d_sync.ds_consumer;
2116 	disk->d_sync.ds_consumer = NULL;
2117 	disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2118 	sc->sc_sync.ds_ndisks--;
2119 	sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
2120 	g_topology_lock();
2121 	g_mirror_kill_consumer(sc, cp);
2122 	g_topology_unlock();
2123 	sx_xlock(&sc->sc_lock);
2124 }
2125 
2126 static void
2127 g_mirror_launch_provider(struct g_mirror_softc *sc)
2128 {
2129 	struct g_mirror_disk *disk;
2130 	struct g_provider *pp, *dp;
2131 
2132 	sx_assert(&sc->sc_lock, SX_LOCKED);
2133 
2134 	g_topology_lock();
2135 	pp = g_new_providerf(sc->sc_geom, "mirror/%s", sc->sc_name);
2136 	pp->flags |= G_PF_DIRECT_RECEIVE;
2137 	pp->mediasize = sc->sc_mediasize;
2138 	pp->sectorsize = sc->sc_sectorsize;
2139 	pp->stripesize = 0;
2140 	pp->stripeoffset = 0;
2141 
2142 	/* Splitting of unmapped BIO's could work but isn't implemented now */
2143 	if (sc->sc_balance != G_MIRROR_BALANCE_SPLIT)
2144 		pp->flags |= G_PF_ACCEPT_UNMAPPED;
2145 
2146 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2147 		if (disk->d_consumer && disk->d_consumer->provider) {
2148 			dp = disk->d_consumer->provider;
2149 			if (dp->stripesize > pp->stripesize) {
2150 				pp->stripesize = dp->stripesize;
2151 				pp->stripeoffset = dp->stripeoffset;
2152 			}
2153 			/* A provider underneath us doesn't support unmapped */
2154 			if ((dp->flags & G_PF_ACCEPT_UNMAPPED) == 0) {
2155 				G_MIRROR_DEBUG(0, "Cancelling unmapped "
2156 				    "because of %s.", dp->name);
2157 				pp->flags &= ~G_PF_ACCEPT_UNMAPPED;
2158 			}
2159 		}
2160 	}
2161 	pp->private = sc;
2162 	sc->sc_refcnt++;
2163 	sc->sc_provider = pp;
2164 	g_error_provider(pp, 0);
2165 	g_topology_unlock();
2166 	G_MIRROR_DEBUG(0, "Device %s launched (%u/%u).", pp->name,
2167 	    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE), sc->sc_ndisks);
2168 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2169 		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2170 			g_mirror_sync_start(disk);
2171 	}
2172 }
2173 
2174 static void
2175 g_mirror_destroy_provider(struct g_mirror_softc *sc)
2176 {
2177 	struct g_mirror_disk *disk;
2178 	struct bio *bp;
2179 
2180 	g_topology_assert_not();
2181 	KASSERT(sc->sc_provider != NULL, ("NULL provider (device=%s).",
2182 	    sc->sc_name));
2183 
2184 	LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2185 		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2186 			g_mirror_sync_stop(disk, 1);
2187 	}
2188 
2189 	g_topology_lock();
2190 	g_error_provider(sc->sc_provider, ENXIO);
2191 	mtx_lock(&sc->sc_queue_mtx);
2192 	while ((bp = bioq_takefirst(&sc->sc_queue)) != NULL) {
2193 		/*
2194 		 * Abort any pending I/O that wasn't generated by us.
2195 		 * Synchronization requests and requests destined for individual
2196 		 * mirror components can be destroyed immediately.
2197 		 */
2198 		if (bp->bio_to == sc->sc_provider &&
2199 		    bp->bio_from->geom != sc->sc_sync.ds_geom) {
2200 			g_io_deliver(bp, ENXIO);
2201 		} else {
2202 			if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0)
2203 				free(bp->bio_data, M_MIRROR);
2204 			g_destroy_bio(bp);
2205 		}
2206 	}
2207 	mtx_unlock(&sc->sc_queue_mtx);
2208 	g_wither_provider(sc->sc_provider, ENXIO);
2209 	sc->sc_provider = NULL;
2210 	G_MIRROR_DEBUG(0, "Device %s: provider destroyed.", sc->sc_name);
2211 	g_topology_unlock();
2212 }
2213 
2214 static void
2215 g_mirror_go(void *arg)
2216 {
2217 	struct g_mirror_softc *sc;
2218 
2219 	sc = arg;
2220 	G_MIRROR_DEBUG(0, "Force device %s start due to timeout.", sc->sc_name);
2221 	g_mirror_event_send(sc, 0,
2222 	    G_MIRROR_EVENT_DONTWAIT | G_MIRROR_EVENT_DEVICE);
2223 }
2224 
2225 static u_int
2226 g_mirror_determine_state(struct g_mirror_disk *disk)
2227 {
2228 	struct g_mirror_softc *sc;
2229 	u_int state;
2230 
2231 	sc = disk->d_softc;
2232 	if (sc->sc_syncid == disk->d_sync.ds_syncid) {
2233 		if ((disk->d_flags &
2234 		    G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0 &&
2235 		    (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 0 ||
2236 		     (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) == 0)) {
2237 			/* Disk does not need synchronization. */
2238 			state = G_MIRROR_DISK_STATE_ACTIVE;
2239 		} else {
2240 			if ((sc->sc_flags &
2241 			     G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2242 			    (disk->d_flags &
2243 			     G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2244 				/*
2245 				 * We can start synchronization from
2246 				 * the stored offset.
2247 				 */
2248 				state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2249 			} else {
2250 				state = G_MIRROR_DISK_STATE_STALE;
2251 			}
2252 		}
2253 	} else if (disk->d_sync.ds_syncid < sc->sc_syncid) {
2254 		/*
2255 		 * Reset all synchronization data for this disk,
2256 		 * because if it even was synchronized, it was
2257 		 * synchronized to disks with different syncid.
2258 		 */
2259 		disk->d_flags |= G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2260 		disk->d_sync.ds_offset = 0;
2261 		disk->d_sync.ds_offset_done = 0;
2262 		disk->d_sync.ds_syncid = sc->sc_syncid;
2263 		if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2264 		    (disk->d_flags & G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2265 			state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2266 		} else {
2267 			state = G_MIRROR_DISK_STATE_STALE;
2268 		}
2269 	} else /* if (sc->sc_syncid < disk->d_sync.ds_syncid) */ {
2270 		/*
2271 		 * Not good, NOT GOOD!
2272 		 * It means that mirror was started on stale disks
2273 		 * and more fresh disk just arrive.
2274 		 * If there were writes, mirror is broken, sorry.
2275 		 * I think the best choice here is don't touch
2276 		 * this disk and inform the user loudly.
2277 		 */
2278 		G_MIRROR_DEBUG(0, "Device %s was started before the freshest "
2279 		    "disk (%s) arrives!! It will not be connected to the "
2280 		    "running device.", sc->sc_name,
2281 		    g_mirror_get_diskname(disk));
2282 		g_mirror_destroy_disk(disk);
2283 		state = G_MIRROR_DISK_STATE_NONE;
2284 		/* Return immediately, because disk was destroyed. */
2285 		return (state);
2286 	}
2287 	G_MIRROR_DEBUG(3, "State for %s disk: %s.",
2288 	    g_mirror_get_diskname(disk), g_mirror_disk_state2str(state));
2289 	return (state);
2290 }
2291 
2292 /*
2293  * Update device state.
2294  */
2295 static void
2296 g_mirror_update_device(struct g_mirror_softc *sc, bool force)
2297 {
2298 	struct g_mirror_disk *disk;
2299 	u_int state;
2300 
2301 	sx_assert(&sc->sc_lock, SX_XLOCKED);
2302 
2303 	switch (sc->sc_state) {
2304 	case G_MIRROR_DEVICE_STATE_STARTING:
2305 	    {
2306 		struct g_mirror_disk *pdisk, *tdisk;
2307 		u_int dirty, ndisks, genid, syncid;
2308 		bool broken;
2309 
2310 		KASSERT(sc->sc_provider == NULL,
2311 		    ("Non-NULL provider in STARTING state (%s).", sc->sc_name));
2312 		/*
2313 		 * Are we ready? We are, if all disks are connected or
2314 		 * if we have any disks and 'force' is true.
2315 		 */
2316 		ndisks = g_mirror_ndisks(sc, -1);
2317 		if (sc->sc_ndisks == ndisks || (force && ndisks > 0)) {
2318 			;
2319 		} else if (ndisks == 0) {
2320 			/*
2321 			 * Disks went down in starting phase, so destroy
2322 			 * device.
2323 			 */
2324 			callout_drain(&sc->sc_callout);
2325 			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2326 			G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
2327 			    sc->sc_rootmount);
2328 			root_mount_rel(sc->sc_rootmount);
2329 			sc->sc_rootmount = NULL;
2330 			return;
2331 		} else {
2332 			return;
2333 		}
2334 
2335 		/*
2336 		 * Activate all disks with the biggest syncid.
2337 		 */
2338 		if (force) {
2339 			/*
2340 			 * If 'force' is true, we have been called due to
2341 			 * timeout, so don't bother canceling timeout.
2342 			 */
2343 			ndisks = 0;
2344 			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2345 				if ((disk->d_flags &
2346 				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2347 					ndisks++;
2348 				}
2349 			}
2350 			if (ndisks == 0) {
2351 				/* No valid disks found, destroy device. */
2352 				sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2353 				G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2354 				    __LINE__, sc->sc_rootmount);
2355 				root_mount_rel(sc->sc_rootmount);
2356 				sc->sc_rootmount = NULL;
2357 				return;
2358 			}
2359 		} else {
2360 			/* Cancel timeout. */
2361 			callout_drain(&sc->sc_callout);
2362 		}
2363 
2364 		/*
2365 		 * Find the biggest genid.
2366 		 */
2367 		genid = 0;
2368 		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2369 			if (disk->d_genid > genid)
2370 				genid = disk->d_genid;
2371 		}
2372 		sc->sc_genid = genid;
2373 		/*
2374 		 * Remove all disks without the biggest genid.
2375 		 */
2376 		broken = false;
2377 		LIST_FOREACH_SAFE(disk, &sc->sc_disks, d_next, tdisk) {
2378 			if (disk->d_genid < genid) {
2379 				G_MIRROR_DEBUG(0,
2380 				    "Component %s (device %s) broken, skipping.",
2381 				    g_mirror_get_diskname(disk), sc->sc_name);
2382 				g_mirror_destroy_disk(disk);
2383 				/*
2384 				 * Bump the syncid in case we discover a healthy
2385 				 * replacement disk after starting the mirror.
2386 				 */
2387 				broken = true;
2388 			}
2389 		}
2390 
2391 		/*
2392 		 * Find the biggest syncid.
2393 		 */
2394 		syncid = 0;
2395 		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2396 			if (disk->d_sync.ds_syncid > syncid)
2397 				syncid = disk->d_sync.ds_syncid;
2398 		}
2399 
2400 		/*
2401 		 * Here we need to look for dirty disks and if all disks
2402 		 * with the biggest syncid are dirty, we have to choose
2403 		 * one with the biggest priority and rebuild the rest.
2404 		 */
2405 		/*
2406 		 * Find the number of dirty disks with the biggest syncid.
2407 		 * Find the number of disks with the biggest syncid.
2408 		 * While here, find a disk with the biggest priority.
2409 		 */
2410 		dirty = ndisks = 0;
2411 		pdisk = NULL;
2412 		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2413 			if (disk->d_sync.ds_syncid != syncid)
2414 				continue;
2415 			if ((disk->d_flags &
2416 			    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2417 				continue;
2418 			}
2419 			ndisks++;
2420 			if ((disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
2421 				dirty++;
2422 				if (pdisk == NULL ||
2423 				    pdisk->d_priority < disk->d_priority) {
2424 					pdisk = disk;
2425 				}
2426 			}
2427 		}
2428 		if (dirty == 0) {
2429 			/* No dirty disks at all, great. */
2430 		} else if (dirty == ndisks) {
2431 			/*
2432 			 * Force synchronization for all dirty disks except one
2433 			 * with the biggest priority.
2434 			 */
2435 			KASSERT(pdisk != NULL, ("pdisk == NULL"));
2436 			G_MIRROR_DEBUG(1, "Using disk %s (device %s) as a "
2437 			    "master disk for synchronization.",
2438 			    g_mirror_get_diskname(pdisk), sc->sc_name);
2439 			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2440 				if (disk->d_sync.ds_syncid != syncid)
2441 					continue;
2442 				if ((disk->d_flags &
2443 				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2444 					continue;
2445 				}
2446 				KASSERT((disk->d_flags &
2447 				    G_MIRROR_DISK_FLAG_DIRTY) != 0,
2448 				    ("Disk %s isn't marked as dirty.",
2449 				    g_mirror_get_diskname(disk)));
2450 				/* Skip the disk with the biggest priority. */
2451 				if (disk == pdisk)
2452 					continue;
2453 				disk->d_sync.ds_syncid = 0;
2454 			}
2455 		} else if (dirty < ndisks) {
2456 			/*
2457 			 * Force synchronization for all dirty disks.
2458 			 * We have some non-dirty disks.
2459 			 */
2460 			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2461 				if (disk->d_sync.ds_syncid != syncid)
2462 					continue;
2463 				if ((disk->d_flags &
2464 				    G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2465 					continue;
2466 				}
2467 				if ((disk->d_flags &
2468 				    G_MIRROR_DISK_FLAG_DIRTY) == 0) {
2469 					continue;
2470 				}
2471 				disk->d_sync.ds_syncid = 0;
2472 			}
2473 		}
2474 
2475 		/* Reset hint. */
2476 		sc->sc_hint = NULL;
2477 		sc->sc_syncid = syncid;
2478 		if (force || broken) {
2479 			/* Remember to bump syncid on first write. */
2480 			sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2481 		}
2482 		state = G_MIRROR_DEVICE_STATE_RUNNING;
2483 		G_MIRROR_DEBUG(1, "Device %s state changed from %s to %s.",
2484 		    sc->sc_name, g_mirror_device_state2str(sc->sc_state),
2485 		    g_mirror_device_state2str(state));
2486 		sc->sc_state = state;
2487 		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2488 			state = g_mirror_determine_state(disk);
2489 			g_mirror_event_send(disk, state,
2490 			    G_MIRROR_EVENT_DONTWAIT);
2491 			if (state == G_MIRROR_DISK_STATE_STALE)
2492 				sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2493 		}
2494 		break;
2495 	    }
2496 	case G_MIRROR_DEVICE_STATE_RUNNING:
2497 		if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 0 &&
2498 		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2499 			/*
2500 			 * No usable disks, so destroy the device.
2501 			 */
2502 			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2503 			break;
2504 		} else if (g_mirror_ndisks(sc,
2505 		    G_MIRROR_DISK_STATE_ACTIVE) > 0 &&
2506 		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2507 			/*
2508 			 * We have active disks, launch provider if it doesn't
2509 			 * exist.
2510 			 */
2511 			if (sc->sc_provider == NULL)
2512 				g_mirror_launch_provider(sc);
2513 			if (sc->sc_rootmount != NULL) {
2514 				G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2515 				    __LINE__, sc->sc_rootmount);
2516 				root_mount_rel(sc->sc_rootmount);
2517 				sc->sc_rootmount = NULL;
2518 			}
2519 		}
2520 		/*
2521 		 * Genid should be bumped immediately, so do it here.
2522 		 */
2523 		if ((sc->sc_bump_id & G_MIRROR_BUMP_GENID) != 0) {
2524 			sc->sc_bump_id &= ~G_MIRROR_BUMP_GENID;
2525 			g_mirror_bump_genid(sc);
2526 		}
2527 		if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID_NOW) != 0) {
2528 			sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID_NOW;
2529 			g_mirror_bump_syncid(sc);
2530 		}
2531 		break;
2532 	default:
2533 		KASSERT(1 == 0, ("Wrong device state (%s, %s).",
2534 		    sc->sc_name, g_mirror_device_state2str(sc->sc_state)));
2535 		break;
2536 	}
2537 }
2538 
2539 /*
2540  * Update disk state and device state if needed.
2541  */
2542 #define	DISK_STATE_CHANGED()	G_MIRROR_DEBUG(1,			\
2543 	"Disk %s state changed from %s to %s (device %s).",		\
2544 	g_mirror_get_diskname(disk),					\
2545 	g_mirror_disk_state2str(disk->d_state),				\
2546 	g_mirror_disk_state2str(state), sc->sc_name)
2547 static int
2548 g_mirror_update_disk(struct g_mirror_disk *disk, u_int state)
2549 {
2550 	struct g_mirror_softc *sc;
2551 
2552 	sc = disk->d_softc;
2553 	sx_assert(&sc->sc_lock, SX_XLOCKED);
2554 
2555 again:
2556 	G_MIRROR_DEBUG(3, "Changing disk %s state from %s to %s.",
2557 	    g_mirror_get_diskname(disk), g_mirror_disk_state2str(disk->d_state),
2558 	    g_mirror_disk_state2str(state));
2559 	switch (state) {
2560 	case G_MIRROR_DISK_STATE_NEW:
2561 		/*
2562 		 * Possible scenarios:
2563 		 * 1. New disk arrive.
2564 		 */
2565 		/* Previous state should be NONE. */
2566 		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NONE,
2567 		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2568 		    g_mirror_disk_state2str(disk->d_state)));
2569 		DISK_STATE_CHANGED();
2570 
2571 		disk->d_state = state;
2572 		if (LIST_EMPTY(&sc->sc_disks))
2573 			LIST_INSERT_HEAD(&sc->sc_disks, disk, d_next);
2574 		else {
2575 			struct g_mirror_disk *dp;
2576 
2577 			LIST_FOREACH(dp, &sc->sc_disks, d_next) {
2578 				if (disk->d_priority >= dp->d_priority) {
2579 					LIST_INSERT_BEFORE(dp, disk, d_next);
2580 					dp = NULL;
2581 					break;
2582 				}
2583 				if (LIST_NEXT(dp, d_next) == NULL)
2584 					break;
2585 			}
2586 			if (dp != NULL)
2587 				LIST_INSERT_AFTER(dp, disk, d_next);
2588 		}
2589 		G_MIRROR_DEBUG(1, "Device %s: provider %s detected.",
2590 		    sc->sc_name, g_mirror_get_diskname(disk));
2591 		if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
2592 			break;
2593 		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2594 		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2595 		    g_mirror_device_state2str(sc->sc_state),
2596 		    g_mirror_get_diskname(disk),
2597 		    g_mirror_disk_state2str(disk->d_state)));
2598 		state = g_mirror_determine_state(disk);
2599 		if (state != G_MIRROR_DISK_STATE_NONE)
2600 			goto again;
2601 		break;
2602 	case G_MIRROR_DISK_STATE_ACTIVE:
2603 		/*
2604 		 * Possible scenarios:
2605 		 * 1. New disk does not need synchronization.
2606 		 * 2. Synchronization process finished successfully.
2607 		 */
2608 		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2609 		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2610 		    g_mirror_device_state2str(sc->sc_state),
2611 		    g_mirror_get_diskname(disk),
2612 		    g_mirror_disk_state2str(disk->d_state)));
2613 		/* Previous state should be NEW or SYNCHRONIZING. */
2614 		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW ||
2615 		    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2616 		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2617 		    g_mirror_disk_state2str(disk->d_state)));
2618 		DISK_STATE_CHANGED();
2619 
2620 		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
2621 			disk->d_flags &= ~G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2622 			disk->d_flags &= ~G_MIRROR_DISK_FLAG_FORCE_SYNC;
2623 			g_mirror_sync_stop(disk, 0);
2624 		}
2625 		disk->d_state = state;
2626 		disk->d_sync.ds_offset = 0;
2627 		disk->d_sync.ds_offset_done = 0;
2628 		g_mirror_update_idle(sc, disk);
2629 		g_mirror_update_metadata(disk);
2630 		G_MIRROR_DEBUG(1, "Device %s: provider %s activated.",
2631 		    sc->sc_name, g_mirror_get_diskname(disk));
2632 		break;
2633 	case G_MIRROR_DISK_STATE_STALE:
2634 		/*
2635 		 * Possible scenarios:
2636 		 * 1. Stale disk was connected.
2637 		 */
2638 		/* Previous state should be NEW. */
2639 		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2640 		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2641 		    g_mirror_disk_state2str(disk->d_state)));
2642 		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2643 		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2644 		    g_mirror_device_state2str(sc->sc_state),
2645 		    g_mirror_get_diskname(disk),
2646 		    g_mirror_disk_state2str(disk->d_state)));
2647 		/*
2648 		 * STALE state is only possible if device is marked
2649 		 * NOAUTOSYNC.
2650 		 */
2651 		KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0,
2652 		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2653 		    g_mirror_device_state2str(sc->sc_state),
2654 		    g_mirror_get_diskname(disk),
2655 		    g_mirror_disk_state2str(disk->d_state)));
2656 		DISK_STATE_CHANGED();
2657 
2658 		disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2659 		disk->d_state = state;
2660 		g_mirror_update_metadata(disk);
2661 		G_MIRROR_DEBUG(0, "Device %s: provider %s is stale.",
2662 		    sc->sc_name, g_mirror_get_diskname(disk));
2663 		break;
2664 	case G_MIRROR_DISK_STATE_SYNCHRONIZING:
2665 		/*
2666 		 * Possible scenarios:
2667 		 * 1. Disk which needs synchronization was connected.
2668 		 */
2669 		/* Previous state should be NEW. */
2670 		KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2671 		    ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2672 		    g_mirror_disk_state2str(disk->d_state)));
2673 		KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2674 		    ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2675 		    g_mirror_device_state2str(sc->sc_state),
2676 		    g_mirror_get_diskname(disk),
2677 		    g_mirror_disk_state2str(disk->d_state)));
2678 		DISK_STATE_CHANGED();
2679 
2680 		if (disk->d_state == G_MIRROR_DISK_STATE_NEW)
2681 			disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2682 		disk->d_state = state;
2683 		if (sc->sc_provider != NULL) {
2684 			g_mirror_sync_start(disk);
2685 			g_mirror_update_metadata(disk);
2686 		}
2687 		break;
2688 	case G_MIRROR_DISK_STATE_DISCONNECTED:
2689 		/*
2690 		 * Possible scenarios:
2691 		 * 1. Device wasn't running yet, but disk disappear.
2692 		 * 2. Disk was active and disapppear.
2693 		 * 3. Disk disappear during synchronization process.
2694 		 */
2695 		if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING) {
2696 			/*
2697 			 * Previous state should be ACTIVE, STALE or
2698 			 * SYNCHRONIZING.
2699 			 */
2700 			KASSERT(disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
2701 			    disk->d_state == G_MIRROR_DISK_STATE_STALE ||
2702 			    disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2703 			    ("Wrong disk state (%s, %s).",
2704 			    g_mirror_get_diskname(disk),
2705 			    g_mirror_disk_state2str(disk->d_state)));
2706 		} else if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING) {
2707 			/* Previous state should be NEW. */
2708 			KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2709 			    ("Wrong disk state (%s, %s).",
2710 			    g_mirror_get_diskname(disk),
2711 			    g_mirror_disk_state2str(disk->d_state)));
2712 			/*
2713 			 * Reset bumping syncid if disk disappeared in STARTING
2714 			 * state.
2715 			 */
2716 			if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0)
2717 				sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
2718 #ifdef	INVARIANTS
2719 		} else {
2720 			KASSERT(1 == 0, ("Wrong device state (%s, %s, %s, %s).",
2721 			    sc->sc_name,
2722 			    g_mirror_device_state2str(sc->sc_state),
2723 			    g_mirror_get_diskname(disk),
2724 			    g_mirror_disk_state2str(disk->d_state)));
2725 #endif
2726 		}
2727 		DISK_STATE_CHANGED();
2728 		G_MIRROR_DEBUG(0, "Device %s: provider %s disconnected.",
2729 		    sc->sc_name, g_mirror_get_diskname(disk));
2730 
2731 		g_mirror_destroy_disk(disk);
2732 		break;
2733 	case G_MIRROR_DISK_STATE_DESTROY:
2734 	    {
2735 		int error;
2736 
2737 		error = g_mirror_clear_metadata(disk);
2738 		if (error != 0) {
2739 			G_MIRROR_DEBUG(0,
2740 			    "Device %s: failed to clear metadata on %s: %d.",
2741 			    sc->sc_name, g_mirror_get_diskname(disk), error);
2742 			break;
2743 		}
2744 		DISK_STATE_CHANGED();
2745 		G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.",
2746 		    sc->sc_name, g_mirror_get_diskname(disk));
2747 
2748 		g_mirror_destroy_disk(disk);
2749 		sc->sc_ndisks--;
2750 		LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2751 			g_mirror_update_metadata(disk);
2752 		}
2753 		break;
2754 	    }
2755 	default:
2756 		KASSERT(1 == 0, ("Unknown state (%u).", state));
2757 		break;
2758 	}
2759 	return (0);
2760 }
2761 #undef	DISK_STATE_CHANGED
2762 
2763 int
2764 g_mirror_read_metadata(struct g_consumer *cp, struct g_mirror_metadata *md)
2765 {
2766 	struct g_provider *pp;
2767 	u_char *buf;
2768 	int error;
2769 
2770 	g_topology_assert();
2771 
2772 	error = g_access(cp, 1, 0, 0);
2773 	if (error != 0)
2774 		return (error);
2775 	pp = cp->provider;
2776 	g_topology_unlock();
2777 	/* Metadata are stored on last sector. */
2778 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
2779 	    &error);
2780 	g_topology_lock();
2781 	g_access(cp, -1, 0, 0);
2782 	if (buf == NULL) {
2783 		G_MIRROR_DEBUG(1, "Cannot read metadata from %s (error=%d).",
2784 		    cp->provider->name, error);
2785 		return (error);
2786 	}
2787 
2788 	/* Decode metadata. */
2789 	error = mirror_metadata_decode(buf, md);
2790 	g_free(buf);
2791 	if (strcmp(md->md_magic, G_MIRROR_MAGIC) != 0)
2792 		return (EINVAL);
2793 	if (md->md_version > G_MIRROR_VERSION) {
2794 		G_MIRROR_DEBUG(0,
2795 		    "Kernel module is too old to handle metadata from %s.",
2796 		    cp->provider->name);
2797 		return (EINVAL);
2798 	}
2799 	if (error != 0) {
2800 		G_MIRROR_DEBUG(1, "MD5 metadata hash mismatch for provider %s.",
2801 		    cp->provider->name);
2802 		return (error);
2803 	}
2804 
2805 	return (0);
2806 }
2807 
2808 static int
2809 g_mirror_check_metadata(struct g_mirror_softc *sc, struct g_provider *pp,
2810     struct g_mirror_metadata *md)
2811 {
2812 
2813 	if (g_mirror_id2disk(sc, md->md_did) != NULL) {
2814 		G_MIRROR_DEBUG(1, "Disk %s (id=%u) already exists, skipping.",
2815 		    pp->name, md->md_did);
2816 		return (EEXIST);
2817 	}
2818 	if (md->md_all != sc->sc_ndisks) {
2819 		G_MIRROR_DEBUG(1,
2820 		    "Invalid '%s' field on disk %s (device %s), skipping.",
2821 		    "md_all", pp->name, sc->sc_name);
2822 		return (EINVAL);
2823 	}
2824 	if (md->md_slice != sc->sc_slice) {
2825 		G_MIRROR_DEBUG(1,
2826 		    "Invalid '%s' field on disk %s (device %s), skipping.",
2827 		    "md_slice", pp->name, sc->sc_name);
2828 		return (EINVAL);
2829 	}
2830 	if (md->md_balance != sc->sc_balance) {
2831 		G_MIRROR_DEBUG(1,
2832 		    "Invalid '%s' field on disk %s (device %s), skipping.",
2833 		    "md_balance", pp->name, sc->sc_name);
2834 		return (EINVAL);
2835 	}
2836 #if 0
2837 	if (md->md_mediasize != sc->sc_mediasize) {
2838 		G_MIRROR_DEBUG(1,
2839 		    "Invalid '%s' field on disk %s (device %s), skipping.",
2840 		    "md_mediasize", pp->name, sc->sc_name);
2841 		return (EINVAL);
2842 	}
2843 #endif
2844 	if (sc->sc_mediasize > pp->mediasize) {
2845 		G_MIRROR_DEBUG(1,
2846 		    "Invalid size of disk %s (device %s), skipping.", pp->name,
2847 		    sc->sc_name);
2848 		return (EINVAL);
2849 	}
2850 	if (md->md_sectorsize != sc->sc_sectorsize) {
2851 		G_MIRROR_DEBUG(1,
2852 		    "Invalid '%s' field on disk %s (device %s), skipping.",
2853 		    "md_sectorsize", pp->name, sc->sc_name);
2854 		return (EINVAL);
2855 	}
2856 	if ((sc->sc_sectorsize % pp->sectorsize) != 0) {
2857 		G_MIRROR_DEBUG(1,
2858 		    "Invalid sector size of disk %s (device %s), skipping.",
2859 		    pp->name, sc->sc_name);
2860 		return (EINVAL);
2861 	}
2862 	if ((md->md_mflags & ~G_MIRROR_DEVICE_FLAG_MASK) != 0) {
2863 		G_MIRROR_DEBUG(1,
2864 		    "Invalid device flags on disk %s (device %s), skipping.",
2865 		    pp->name, sc->sc_name);
2866 		return (EINVAL);
2867 	}
2868 	if ((md->md_dflags & ~G_MIRROR_DISK_FLAG_MASK) != 0) {
2869 		G_MIRROR_DEBUG(1,
2870 		    "Invalid disk flags on disk %s (device %s), skipping.",
2871 		    pp->name, sc->sc_name);
2872 		return (EINVAL);
2873 	}
2874 	return (0);
2875 }
2876 
2877 int
2878 g_mirror_add_disk(struct g_mirror_softc *sc, struct g_provider *pp,
2879     struct g_mirror_metadata *md)
2880 {
2881 	struct g_mirror_disk *disk;
2882 	int error;
2883 
2884 	g_topology_assert_not();
2885 	G_MIRROR_DEBUG(2, "Adding disk %s.", pp->name);
2886 
2887 	error = g_mirror_check_metadata(sc, pp, md);
2888 	if (error != 0)
2889 		return (error);
2890 	if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING &&
2891 	    md->md_genid < sc->sc_genid) {
2892 		G_MIRROR_DEBUG(0, "Component %s (device %s) broken, skipping.",
2893 		    pp->name, sc->sc_name);
2894 		return (EINVAL);
2895 	}
2896 	disk = g_mirror_init_disk(sc, pp, md, &error);
2897 	if (disk == NULL)
2898 		return (error);
2899 	error = g_mirror_event_send(disk, G_MIRROR_DISK_STATE_NEW,
2900 	    G_MIRROR_EVENT_WAIT);
2901 	if (error != 0)
2902 		return (error);
2903 	if (md->md_version < G_MIRROR_VERSION) {
2904 		G_MIRROR_DEBUG(0, "Upgrading metadata on %s (v%d->v%d).",
2905 		    pp->name, md->md_version, G_MIRROR_VERSION);
2906 		g_mirror_update_metadata(disk);
2907 	}
2908 	return (0);
2909 }
2910 
2911 static void
2912 g_mirror_destroy_delayed(void *arg, int flag)
2913 {
2914 	struct g_mirror_softc *sc;
2915 	int error;
2916 
2917 	if (flag == EV_CANCEL) {
2918 		G_MIRROR_DEBUG(1, "Destroying canceled.");
2919 		return;
2920 	}
2921 	sc = arg;
2922 	g_topology_unlock();
2923 	sx_xlock(&sc->sc_lock);
2924 	KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) == 0,
2925 	    ("DESTROY flag set on %s.", sc->sc_name));
2926 	KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_CLOSEWAIT) != 0,
2927 	    ("CLOSEWAIT flag not set on %s.", sc->sc_name));
2928 	G_MIRROR_DEBUG(1, "Destroying %s (delayed).", sc->sc_name);
2929 	error = g_mirror_destroy(sc, G_MIRROR_DESTROY_SOFT);
2930 	if (error != 0) {
2931 		G_MIRROR_DEBUG(0, "Cannot destroy %s (error=%d).",
2932 		    sc->sc_name, error);
2933 		sx_xunlock(&sc->sc_lock);
2934 	}
2935 	g_topology_lock();
2936 }
2937 
2938 static int
2939 g_mirror_access(struct g_provider *pp, int acr, int acw, int ace)
2940 {
2941 	struct g_mirror_softc *sc;
2942 	int error = 0;
2943 
2944 	g_topology_assert();
2945 	G_MIRROR_DEBUG(2, "Access request for %s: r%dw%de%d.", pp->name, acr,
2946 	    acw, ace);
2947 
2948 	sc = pp->private;
2949 	KASSERT(sc != NULL, ("NULL softc (provider=%s).", pp->name));
2950 
2951 	g_topology_unlock();
2952 	sx_xlock(&sc->sc_lock);
2953 	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0 ||
2954 	    (sc->sc_flags & G_MIRROR_DEVICE_FLAG_CLOSEWAIT) != 0 ||
2955 	    LIST_EMPTY(&sc->sc_disks)) {
2956 		if (acr > 0 || acw > 0 || ace > 0)
2957 			error = ENXIO;
2958 		goto end;
2959 	}
2960 	sc->sc_provider_open += acr + acw + ace;
2961 	if (pp->acw + acw == 0)
2962 		g_mirror_idle(sc, 0);
2963 	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_CLOSEWAIT) != 0 &&
2964 	    sc->sc_provider_open == 0)
2965 		g_post_event(g_mirror_destroy_delayed, sc, M_WAITOK, sc, NULL);
2966 end:
2967 	sx_xunlock(&sc->sc_lock);
2968 	g_topology_lock();
2969 	return (error);
2970 }
2971 
2972 struct g_geom *
2973 g_mirror_create(struct g_class *mp, const struct g_mirror_metadata *md,
2974     u_int type)
2975 {
2976 	struct g_mirror_softc *sc;
2977 	struct g_geom *gp;
2978 	int error, timeout;
2979 
2980 	g_topology_assert();
2981 	G_MIRROR_DEBUG(1, "Creating device %s (id=%u).", md->md_name,
2982 	    md->md_mid);
2983 
2984 	/* One disk is minimum. */
2985 	if (md->md_all < 1)
2986 		return (NULL);
2987 	/*
2988 	 * Action geom.
2989 	 */
2990 	gp = g_new_geomf(mp, "%s", md->md_name);
2991 	sc = malloc(sizeof(*sc), M_MIRROR, M_WAITOK | M_ZERO);
2992 	gp->start = g_mirror_start;
2993 	gp->orphan = g_mirror_orphan;
2994 	gp->access = g_mirror_access;
2995 	gp->dumpconf = g_mirror_dumpconf;
2996 
2997 	sc->sc_type = type;
2998 	sc->sc_id = md->md_mid;
2999 	sc->sc_slice = md->md_slice;
3000 	sc->sc_balance = md->md_balance;
3001 	sc->sc_mediasize = md->md_mediasize;
3002 	sc->sc_sectorsize = md->md_sectorsize;
3003 	sc->sc_ndisks = md->md_all;
3004 	sc->sc_flags = md->md_mflags;
3005 	sc->sc_bump_id = 0;
3006 	sc->sc_idle = 1;
3007 	sc->sc_last_write = time_uptime;
3008 	sc->sc_writes = 0;
3009 	sc->sc_refcnt = 1;
3010 	sx_init(&sc->sc_lock, "gmirror:lock");
3011 	bioq_init(&sc->sc_queue);
3012 	mtx_init(&sc->sc_queue_mtx, "gmirror:queue", NULL, MTX_DEF);
3013 	bioq_init(&sc->sc_regular_delayed);
3014 	bioq_init(&sc->sc_inflight);
3015 	bioq_init(&sc->sc_sync_delayed);
3016 	LIST_INIT(&sc->sc_disks);
3017 	TAILQ_INIT(&sc->sc_events);
3018 	mtx_init(&sc->sc_events_mtx, "gmirror:events", NULL, MTX_DEF);
3019 	callout_init(&sc->sc_callout, 1);
3020 	mtx_init(&sc->sc_done_mtx, "gmirror:done", NULL, MTX_DEF);
3021 	sc->sc_state = G_MIRROR_DEVICE_STATE_STARTING;
3022 	gp->softc = sc;
3023 	sc->sc_geom = gp;
3024 	sc->sc_provider = NULL;
3025 	sc->sc_provider_open = 0;
3026 	/*
3027 	 * Synchronization geom.
3028 	 */
3029 	gp = g_new_geomf(mp, "%s.sync", md->md_name);
3030 	gp->softc = sc;
3031 	gp->orphan = g_mirror_orphan;
3032 	sc->sc_sync.ds_geom = gp;
3033 	sc->sc_sync.ds_ndisks = 0;
3034 	error = kproc_create(g_mirror_worker, sc, &sc->sc_worker, 0, 0,
3035 	    "g_mirror %s", md->md_name);
3036 	if (error != 0) {
3037 		G_MIRROR_DEBUG(1, "Cannot create kernel thread for %s.",
3038 		    sc->sc_name);
3039 		g_destroy_geom(sc->sc_sync.ds_geom);
3040 		g_destroy_geom(sc->sc_geom);
3041 		g_mirror_free_device(sc);
3042 		return (NULL);
3043 	}
3044 
3045 	G_MIRROR_DEBUG(1, "Device %s created (%u components, id=%u).",
3046 	    sc->sc_name, sc->sc_ndisks, sc->sc_id);
3047 
3048 	sc->sc_rootmount = root_mount_hold("GMIRROR");
3049 	G_MIRROR_DEBUG(1, "root_mount_hold %p", sc->sc_rootmount);
3050 	/*
3051 	 * Run timeout.
3052 	 */
3053 	timeout = g_mirror_timeout * hz;
3054 	callout_reset(&sc->sc_callout, timeout, g_mirror_go, sc);
3055 	return (sc->sc_geom);
3056 }
3057 
3058 int
3059 g_mirror_destroy(struct g_mirror_softc *sc, int how)
3060 {
3061 	struct g_mirror_disk *disk;
3062 
3063 	g_topology_assert_not();
3064 	sx_assert(&sc->sc_lock, SX_XLOCKED);
3065 
3066 	if (sc->sc_provider_open != 0) {
3067 		switch (how) {
3068 		case G_MIRROR_DESTROY_SOFT:
3069 			G_MIRROR_DEBUG(1,
3070 			    "Device %s is still open (%d).", sc->sc_name,
3071 			    sc->sc_provider_open);
3072 			return (EBUSY);
3073 		case G_MIRROR_DESTROY_DELAYED:
3074 			G_MIRROR_DEBUG(1,
3075 			    "Device %s will be destroyed on last close.",
3076 			    sc->sc_name);
3077 			LIST_FOREACH(disk, &sc->sc_disks, d_next) {
3078 				if (disk->d_state ==
3079 				    G_MIRROR_DISK_STATE_SYNCHRONIZING) {
3080 					g_mirror_sync_stop(disk, 1);
3081 				}
3082 			}
3083 			sc->sc_flags |= G_MIRROR_DEVICE_FLAG_CLOSEWAIT;
3084 			return (EBUSY);
3085 		case G_MIRROR_DESTROY_HARD:
3086 			G_MIRROR_DEBUG(1, "Device %s is still open, so it "
3087 			    "can't be definitely removed.", sc->sc_name);
3088 		}
3089 	}
3090 
3091 	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0)
3092 		return (0);
3093 	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
3094 	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DRAIN;
3095 	G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
3096 	sx_xunlock(&sc->sc_lock);
3097 	mtx_lock(&sc->sc_queue_mtx);
3098 	wakeup(sc);
3099 	mtx_unlock(&sc->sc_queue_mtx);
3100 	G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, &sc->sc_worker);
3101 	while (sc->sc_worker != NULL)
3102 		tsleep(&sc->sc_worker, PRIBIO, "m:destroy", hz / 5);
3103 	G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, &sc->sc_worker);
3104 	sx_xlock(&sc->sc_lock);
3105 	g_mirror_destroy_device(sc);
3106 	return (0);
3107 }
3108 
3109 static void
3110 g_mirror_taste_orphan(struct g_consumer *cp)
3111 {
3112 
3113 	KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
3114 	    cp->provider->name));
3115 }
3116 
3117 static struct g_geom *
3118 g_mirror_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
3119 {
3120 	struct g_mirror_metadata md;
3121 	struct g_mirror_softc *sc;
3122 	struct g_consumer *cp;
3123 	struct g_geom *gp;
3124 	int error;
3125 
3126 	g_topology_assert();
3127 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
3128 	G_MIRROR_DEBUG(2, "Tasting %s.", pp->name);
3129 
3130 	gp = g_new_geomf(mp, "mirror:taste");
3131 	/*
3132 	 * This orphan function should be never called.
3133 	 */
3134 	gp->orphan = g_mirror_taste_orphan;
3135 	cp = g_new_consumer(gp);
3136 	g_attach(cp, pp);
3137 	error = g_mirror_read_metadata(cp, &md);
3138 	g_detach(cp);
3139 	g_destroy_consumer(cp);
3140 	g_destroy_geom(gp);
3141 	if (error != 0)
3142 		return (NULL);
3143 	gp = NULL;
3144 
3145 	if (md.md_provider[0] != '\0' &&
3146 	    !g_compare_names(md.md_provider, pp->name))
3147 		return (NULL);
3148 	if (md.md_provsize != 0 && md.md_provsize != pp->mediasize)
3149 		return (NULL);
3150 	if ((md.md_dflags & G_MIRROR_DISK_FLAG_INACTIVE) != 0) {
3151 		G_MIRROR_DEBUG(0,
3152 		    "Device %s: provider %s marked as inactive, skipping.",
3153 		    md.md_name, pp->name);
3154 		return (NULL);
3155 	}
3156 	if (g_mirror_debug >= 2)
3157 		mirror_metadata_dump(&md);
3158 
3159 	/*
3160 	 * Let's check if device already exists.
3161 	 */
3162 	sc = NULL;
3163 	LIST_FOREACH(gp, &mp->geom, geom) {
3164 		sc = gp->softc;
3165 		if (sc == NULL)
3166 			continue;
3167 		if (sc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
3168 			continue;
3169 		if (sc->sc_sync.ds_geom == gp)
3170 			continue;
3171 		if (strcmp(md.md_name, sc->sc_name) != 0)
3172 			continue;
3173 		if (md.md_mid != sc->sc_id) {
3174 			G_MIRROR_DEBUG(0, "Device %s already configured.",
3175 			    sc->sc_name);
3176 			return (NULL);
3177 		}
3178 		break;
3179 	}
3180 	if (gp == NULL) {
3181 		gp = g_mirror_create(mp, &md, G_MIRROR_TYPE_AUTOMATIC);
3182 		if (gp == NULL) {
3183 			G_MIRROR_DEBUG(0, "Cannot create device %s.",
3184 			    md.md_name);
3185 			return (NULL);
3186 		}
3187 		sc = gp->softc;
3188 	}
3189 	G_MIRROR_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
3190 	g_topology_unlock();
3191 	sx_xlock(&sc->sc_lock);
3192 	sc->sc_flags |= G_MIRROR_DEVICE_FLAG_TASTING;
3193 	error = g_mirror_add_disk(sc, pp, &md);
3194 	if (error != 0) {
3195 		G_MIRROR_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
3196 		    pp->name, gp->name, error);
3197 		if (LIST_EMPTY(&sc->sc_disks)) {
3198 			g_cancel_event(sc);
3199 			g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
3200 			g_topology_lock();
3201 			return (NULL);
3202 		}
3203 		gp = NULL;
3204 	}
3205 	sc->sc_flags &= ~G_MIRROR_DEVICE_FLAG_TASTING;
3206 	if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
3207 		g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
3208 		g_topology_lock();
3209 		return (NULL);
3210 	}
3211 	sx_xunlock(&sc->sc_lock);
3212 	g_topology_lock();
3213 	return (gp);
3214 }
3215 
3216 static void
3217 g_mirror_resize(struct g_consumer *cp)
3218 {
3219 	struct g_mirror_disk *disk;
3220 
3221 	g_topology_assert();
3222 	g_trace(G_T_TOPOLOGY, "%s(%s)", __func__, cp->provider->name);
3223 
3224 	disk = cp->private;
3225 	if (disk == NULL)
3226 		return;
3227 	g_topology_unlock();
3228 	g_mirror_update_metadata(disk);
3229 	g_topology_lock();
3230 }
3231 
3232 static int
3233 g_mirror_destroy_geom(struct gctl_req *req __unused,
3234     struct g_class *mp __unused, struct g_geom *gp)
3235 {
3236 	struct g_mirror_softc *sc;
3237 	int error;
3238 
3239 	g_topology_unlock();
3240 	sc = gp->softc;
3241 	sx_xlock(&sc->sc_lock);
3242 	g_cancel_event(sc);
3243 	error = g_mirror_destroy(gp->softc, G_MIRROR_DESTROY_SOFT);
3244 	if (error != 0)
3245 		sx_xunlock(&sc->sc_lock);
3246 	g_topology_lock();
3247 	return (error);
3248 }
3249 
3250 static void
3251 g_mirror_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
3252     struct g_consumer *cp, struct g_provider *pp)
3253 {
3254 	struct g_mirror_softc *sc;
3255 
3256 	g_topology_assert();
3257 
3258 	sc = gp->softc;
3259 	if (sc == NULL)
3260 		return;
3261 	/* Skip synchronization geom. */
3262 	if (gp == sc->sc_sync.ds_geom)
3263 		return;
3264 	if (pp != NULL) {
3265 		/* Nothing here. */
3266 	} else if (cp != NULL) {
3267 		struct g_mirror_disk *disk;
3268 
3269 		disk = cp->private;
3270 		if (disk == NULL)
3271 			return;
3272 		g_topology_unlock();
3273 		sx_xlock(&sc->sc_lock);
3274 		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)disk->d_id);
3275 		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
3276 			sbuf_printf(sb, "%s<Synchronized>", indent);
3277 			if (disk->d_sync.ds_offset == 0)
3278 				sbuf_printf(sb, "0%%");
3279 			else {
3280 				sbuf_printf(sb, "%u%%",
3281 				    (u_int)((disk->d_sync.ds_offset * 100) /
3282 				    sc->sc_provider->mediasize));
3283 			}
3284 			sbuf_printf(sb, "</Synchronized>\n");
3285 			if (disk->d_sync.ds_offset > 0) {
3286 				sbuf_printf(sb, "%s<BytesSynced>%jd"
3287 				    "</BytesSynced>\n", indent,
3288 				    (intmax_t)disk->d_sync.ds_offset);
3289 			}
3290 		}
3291 		sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent,
3292 		    disk->d_sync.ds_syncid);
3293 		sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent,
3294 		    disk->d_genid);
3295 		sbuf_printf(sb, "%s<Flags>", indent);
3296 		if (disk->d_flags == 0)
3297 			sbuf_printf(sb, "NONE");
3298 		else {
3299 			int first = 1;
3300 
3301 #define	ADD_FLAG(flag, name)	do {					\
3302 	if ((disk->d_flags & (flag)) != 0) {				\
3303 		if (!first)						\
3304 			sbuf_printf(sb, ", ");				\
3305 		else							\
3306 			first = 0;					\
3307 		sbuf_printf(sb, name);					\
3308 	}								\
3309 } while (0)
3310 			ADD_FLAG(G_MIRROR_DISK_FLAG_DIRTY, "DIRTY");
3311 			ADD_FLAG(G_MIRROR_DISK_FLAG_HARDCODED, "HARDCODED");
3312 			ADD_FLAG(G_MIRROR_DISK_FLAG_INACTIVE, "INACTIVE");
3313 			ADD_FLAG(G_MIRROR_DISK_FLAG_SYNCHRONIZING,
3314 			    "SYNCHRONIZING");
3315 			ADD_FLAG(G_MIRROR_DISK_FLAG_FORCE_SYNC, "FORCE_SYNC");
3316 			ADD_FLAG(G_MIRROR_DISK_FLAG_BROKEN, "BROKEN");
3317 #undef	ADD_FLAG
3318 		}
3319 		sbuf_printf(sb, "</Flags>\n");
3320 		sbuf_printf(sb, "%s<Priority>%u</Priority>\n", indent,
3321 		    disk->d_priority);
3322 		sbuf_printf(sb, "%s<State>%s</State>\n", indent,
3323 		    g_mirror_disk_state2str(disk->d_state));
3324 		sx_xunlock(&sc->sc_lock);
3325 		g_topology_lock();
3326 	} else {
3327 		g_topology_unlock();
3328 		sx_xlock(&sc->sc_lock);
3329 		sbuf_printf(sb, "%s<Type>", indent);
3330 		switch (sc->sc_type) {
3331 		case G_MIRROR_TYPE_AUTOMATIC:
3332 			sbuf_printf(sb, "AUTOMATIC");
3333 			break;
3334 		case G_MIRROR_TYPE_MANUAL:
3335 			sbuf_printf(sb, "MANUAL");
3336 			break;
3337 		default:
3338 			sbuf_printf(sb, "UNKNOWN");
3339 			break;
3340 		}
3341 		sbuf_printf(sb, "</Type>\n");
3342 		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
3343 		sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent, sc->sc_syncid);
3344 		sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent, sc->sc_genid);
3345 		sbuf_printf(sb, "%s<Flags>", indent);
3346 		if (sc->sc_flags == 0)
3347 			sbuf_printf(sb, "NONE");
3348 		else {
3349 			int first = 1;
3350 
3351 #define	ADD_FLAG(flag, name)	do {					\
3352 	if ((sc->sc_flags & (flag)) != 0) {				\
3353 		if (!first)						\
3354 			sbuf_printf(sb, ", ");				\
3355 		else							\
3356 			first = 0;					\
3357 		sbuf_printf(sb, name);					\
3358 	}								\
3359 } while (0)
3360 			ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOFAILSYNC, "NOFAILSYNC");
3361 			ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOAUTOSYNC, "NOAUTOSYNC");
3362 #undef	ADD_FLAG
3363 		}
3364 		sbuf_printf(sb, "</Flags>\n");
3365 		sbuf_printf(sb, "%s<Slice>%u</Slice>\n", indent,
3366 		    (u_int)sc->sc_slice);
3367 		sbuf_printf(sb, "%s<Balance>%s</Balance>\n", indent,
3368 		    balance_name(sc->sc_balance));
3369 		sbuf_printf(sb, "%s<Components>%u</Components>\n", indent,
3370 		    sc->sc_ndisks);
3371 		sbuf_printf(sb, "%s<State>", indent);
3372 		if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
3373 			sbuf_printf(sb, "%s", "STARTING");
3374 		else if (sc->sc_ndisks ==
3375 		    g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE))
3376 			sbuf_printf(sb, "%s", "COMPLETE");
3377 		else
3378 			sbuf_printf(sb, "%s", "DEGRADED");
3379 		sbuf_printf(sb, "</State>\n");
3380 		sx_xunlock(&sc->sc_lock);
3381 		g_topology_lock();
3382 	}
3383 }
3384 
3385 static void
3386 g_mirror_shutdown_post_sync(void *arg, int howto)
3387 {
3388 	struct g_class *mp;
3389 	struct g_geom *gp, *gp2;
3390 	struct g_mirror_softc *sc;
3391 	int error;
3392 
3393 	if (panicstr != NULL)
3394 		return;
3395 
3396 	mp = arg;
3397 	g_topology_lock();
3398 	g_mirror_shutdown = 1;
3399 	LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
3400 		if ((sc = gp->softc) == NULL)
3401 			continue;
3402 		/* Skip synchronization geom. */
3403 		if (gp == sc->sc_sync.ds_geom)
3404 			continue;
3405 		g_topology_unlock();
3406 		sx_xlock(&sc->sc_lock);
3407 		g_mirror_idle(sc, -1);
3408 		g_cancel_event(sc);
3409 		error = g_mirror_destroy(sc, G_MIRROR_DESTROY_DELAYED);
3410 		if (error != 0)
3411 			sx_xunlock(&sc->sc_lock);
3412 		g_topology_lock();
3413 	}
3414 	g_topology_unlock();
3415 }
3416 
3417 static void
3418 g_mirror_init(struct g_class *mp)
3419 {
3420 
3421 	g_mirror_post_sync = EVENTHANDLER_REGISTER(shutdown_post_sync,
3422 	    g_mirror_shutdown_post_sync, mp, SHUTDOWN_PRI_FIRST);
3423 	if (g_mirror_post_sync == NULL)
3424 		G_MIRROR_DEBUG(0, "Warning! Cannot register shutdown event.");
3425 }
3426 
3427 static void
3428 g_mirror_fini(struct g_class *mp)
3429 {
3430 
3431 	if (g_mirror_post_sync != NULL)
3432 		EVENTHANDLER_DEREGISTER(shutdown_post_sync, g_mirror_post_sync);
3433 }
3434 
3435 DECLARE_GEOM_CLASS(g_mirror_class, g_mirror);
3436