xref: /freebsd/sys/geom/multipath/g_multipath.c (revision a10cee30c94cf5944826d2a495e9cdf339dfbcc8)
1 /*-
2  * Copyright (c) 2011 Alexander Motin <mav@FreeBSD.org>
3  * Copyright (c) 2006-2007 Matthew Jacob <mjacob@FreeBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 /*
28  * Based upon work by Pawel Jakub Dawidek <pjd@FreeBSD.org> for all of the
29  * fine geom examples, and by Poul Henning Kamp <phk@FreeBSD.org> for GEOM
30  * itself, all of which is most gratefully acknowledged.
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
39 #include <sys/lock.h>
40 #include <sys/mutex.h>
41 #include <sys/bio.h>
42 #include <sys/sbuf.h>
43 #include <sys/sysctl.h>
44 #include <sys/kthread.h>
45 #include <sys/malloc.h>
46 #include <geom/geom.h>
47 #include <geom/multipath/g_multipath.h>
48 
49 FEATURE(geom_multipath, "GEOM multipath support");
50 
51 SYSCTL_DECL(_kern_geom);
52 static SYSCTL_NODE(_kern_geom, OID_AUTO, multipath, CTLFLAG_RW, 0,
53     "GEOM_MULTIPATH tunables");
54 static u_int g_multipath_debug = 0;
55 SYSCTL_UINT(_kern_geom_multipath, OID_AUTO, debug, CTLFLAG_RW,
56     &g_multipath_debug, 0, "Debug level");
57 static u_int g_multipath_exclusive = 1;
58 SYSCTL_UINT(_kern_geom_multipath, OID_AUTO, exclusive, CTLFLAG_RW,
59     &g_multipath_exclusive, 0, "Exclusively open providers");
60 
61 static enum {
62 	GKT_NIL,
63 	GKT_RUN,
64 	GKT_DIE
65 } g_multipath_kt_state;
66 static struct bio_queue_head gmtbq;
67 static struct mtx gmtbq_mtx;
68 
69 static void g_multipath_orphan(struct g_consumer *);
70 static void g_multipath_start(struct bio *);
71 static void g_multipath_done(struct bio *);
72 static void g_multipath_done_error(struct bio *);
73 static void g_multipath_kt(void *);
74 
75 static int g_multipath_destroy(struct g_geom *);
76 static int
77 g_multipath_destroy_geom(struct gctl_req *, struct g_class *, struct g_geom *);
78 
79 static struct g_geom *g_multipath_find_geom(struct g_class *, const char *);
80 static int g_multipath_rotate(struct g_geom *);
81 
82 static g_taste_t g_multipath_taste;
83 static g_ctl_req_t g_multipath_config;
84 static g_init_t g_multipath_init;
85 static g_fini_t g_multipath_fini;
86 static g_dumpconf_t g_multipath_dumpconf;
87 
88 struct g_class g_multipath_class = {
89 	.name		= G_MULTIPATH_CLASS_NAME,
90 	.version	= G_VERSION,
91 	.ctlreq		= g_multipath_config,
92 	.taste		= g_multipath_taste,
93 	.destroy_geom	= g_multipath_destroy_geom,
94 	.init		= g_multipath_init,
95 	.fini		= g_multipath_fini
96 };
97 
98 #define	MP_FAIL		0x00000001
99 #define	MP_LOST		0x00000002
100 #define	MP_NEW		0x00000004
101 #define	MP_POSTED	0x00000008
102 #define	MP_BAD		(MP_FAIL | MP_LOST | MP_NEW)
103 #define MP_IDLE		0x00000010
104 #define MP_IDLE_MASK	0xfffffff0
105 
106 static int
107 g_multipath_good(struct g_geom *gp)
108 {
109 	struct g_consumer *cp;
110 	int n = 0;
111 
112 	LIST_FOREACH(cp, &gp->consumer, consumer) {
113 		if ((cp->index & MP_BAD) == 0)
114 			n++;
115 	}
116 	return (n);
117 }
118 
119 static void
120 g_multipath_fault(struct g_consumer *cp, int cause)
121 {
122 	struct g_multipath_softc *sc;
123 	struct g_consumer *lcp;
124 	struct g_geom *gp;
125 
126 	gp = cp->geom;
127 	sc = gp->softc;
128 	cp->index |= cause;
129 	if (g_multipath_good(gp) == 0 && sc->sc_ndisks > 0) {
130 		LIST_FOREACH(lcp, &gp->consumer, consumer) {
131 			if (lcp->provider == NULL ||
132 			    (lcp->index & (MP_LOST | MP_NEW)))
133 				continue;
134 			if (sc->sc_ndisks > 1 && lcp == cp)
135 				continue;
136 			printf("GEOM_MULTIPATH: "
137 			    "all paths in %s were marked FAIL, restore %s\n",
138 			    sc->sc_name, lcp->provider->name);
139 			lcp->index &= ~MP_FAIL;
140 		}
141 	}
142 	if (cp != sc->sc_active)
143 		return;
144 	sc->sc_active = NULL;
145 	LIST_FOREACH(lcp, &gp->consumer, consumer) {
146 		if ((lcp->index & MP_BAD) == 0) {
147 			sc->sc_active = lcp;
148 			break;
149 		}
150 	}
151 	if (sc->sc_active == NULL) {
152 		printf("GEOM_MULTIPATH: out of providers for %s\n",
153 		    sc->sc_name);
154 	} else if (sc->sc_active_active != 1) {
155 		printf("GEOM_MULTIPATH: %s is now active path in %s\n",
156 		    sc->sc_active->provider->name, sc->sc_name);
157 	}
158 }
159 
160 static struct g_consumer *
161 g_multipath_choose(struct g_geom *gp, struct bio *bp)
162 {
163 	struct g_multipath_softc *sc;
164 	struct g_consumer *best, *cp;
165 
166 	sc = gp->softc;
167 	if (sc->sc_active_active == 0 ||
168 	    (sc->sc_active_active == 2 && bp->bio_cmd != BIO_READ))
169 		return (sc->sc_active);
170 	best = NULL;
171 	LIST_FOREACH(cp, &gp->consumer, consumer) {
172 		if (cp->index & MP_BAD)
173 			continue;
174 		cp->index += MP_IDLE;
175 		if (best == NULL || cp->private < best->private ||
176 		    (cp->private == best->private && cp->index > best->index))
177 			best = cp;
178 	}
179 	if (best != NULL)
180 		best->index &= ~MP_IDLE_MASK;
181 	return (best);
182 }
183 
184 static void
185 g_mpd(void *arg, int flags __unused)
186 {
187 	struct g_geom *gp;
188 	struct g_multipath_softc *sc;
189 	struct g_consumer *cp;
190 	int w;
191 
192 	g_topology_assert();
193 	cp = arg;
194 	gp = cp->geom;
195 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0) {
196 		w = cp->acw;
197 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
198 		if (w > 0 && cp->provider != NULL &&
199 		    (cp->provider->geom->flags & G_GEOM_WITHER) == 0) {
200 			g_post_event(g_mpd, cp, M_WAITOK, NULL);
201 			return;
202 		}
203 	}
204 	sc = gp->softc;
205 	mtx_lock(&sc->sc_mtx);
206 	if (cp->provider) {
207 		printf("GEOM_MULTIPATH: %s removed from %s\n",
208 		    cp->provider->name, gp->name);
209 		g_detach(cp);
210 	}
211 	g_destroy_consumer(cp);
212 	mtx_unlock(&sc->sc_mtx);
213 	if (LIST_EMPTY(&gp->consumer))
214 		g_multipath_destroy(gp);
215 }
216 
217 static void
218 g_multipath_orphan(struct g_consumer *cp)
219 {
220 	struct g_multipath_softc *sc;
221 	uintptr_t *cnt;
222 
223 	g_topology_assert();
224 	printf("GEOM_MULTIPATH: %s in %s was disconnected\n",
225 	    cp->provider->name, cp->geom->name);
226 	sc = cp->geom->softc;
227 	cnt = (uintptr_t *)&cp->private;
228 	mtx_lock(&sc->sc_mtx);
229 	sc->sc_ndisks--;
230 	g_multipath_fault(cp, MP_LOST);
231 	if (*cnt == 0 && (cp->index & MP_POSTED) == 0) {
232 		cp->index |= MP_POSTED;
233 		mtx_unlock(&sc->sc_mtx);
234 		g_mpd(cp, 0);
235 	} else
236 		mtx_unlock(&sc->sc_mtx);
237 }
238 
239 static void
240 g_multipath_start(struct bio *bp)
241 {
242 	struct g_multipath_softc *sc;
243 	struct g_geom *gp;
244 	struct g_consumer *cp;
245 	struct bio *cbp;
246 	uintptr_t *cnt;
247 
248 	gp = bp->bio_to->geom;
249 	sc = gp->softc;
250 	KASSERT(sc != NULL, ("NULL sc"));
251 	cbp = g_clone_bio(bp);
252 	if (cbp == NULL) {
253 		g_io_deliver(bp, ENOMEM);
254 		return;
255 	}
256 	mtx_lock(&sc->sc_mtx);
257 	cp = g_multipath_choose(gp, bp);
258 	if (cp == NULL) {
259 		mtx_unlock(&sc->sc_mtx);
260 		g_destroy_bio(cbp);
261 		g_io_deliver(bp, ENXIO);
262 		return;
263 	}
264 	if ((uintptr_t)bp->bio_driver1 < sc->sc_ndisks)
265 		bp->bio_driver1 = (void *)(uintptr_t)sc->sc_ndisks;
266 	cnt = (uintptr_t *)&cp->private;
267 	(*cnt)++;
268 	mtx_unlock(&sc->sc_mtx);
269 	cbp->bio_done = g_multipath_done;
270 	g_io_request(cbp, cp);
271 }
272 
273 static void
274 g_multipath_done(struct bio *bp)
275 {
276 	struct g_multipath_softc *sc;
277 	struct g_consumer *cp;
278 	uintptr_t *cnt;
279 
280 	if (bp->bio_error == ENXIO || bp->bio_error == EIO) {
281 		mtx_lock(&gmtbq_mtx);
282 		bioq_insert_tail(&gmtbq, bp);
283 		mtx_unlock(&gmtbq_mtx);
284 		wakeup(&g_multipath_kt_state);
285 	} else {
286 		cp = bp->bio_from;
287 		sc = cp->geom->softc;
288 		cnt = (uintptr_t *)&cp->private;
289 		mtx_lock(&sc->sc_mtx);
290 		(*cnt)--;
291 		if (*cnt == 0 && (cp->index & MP_LOST)) {
292 			cp->index |= MP_POSTED;
293 			mtx_unlock(&sc->sc_mtx);
294 			g_post_event(g_mpd, cp, M_WAITOK, NULL);
295 		} else
296 			mtx_unlock(&sc->sc_mtx);
297 		g_std_done(bp);
298 	}
299 }
300 
301 static void
302 g_multipath_done_error(struct bio *bp)
303 {
304 	struct bio *pbp;
305 	struct g_geom *gp;
306 	struct g_multipath_softc *sc;
307 	struct g_consumer *cp;
308 	struct g_provider *pp;
309 	uintptr_t *cnt;
310 
311 	/*
312 	 * If we had a failure, we have to check first to see
313 	 * whether the consumer it failed on was the currently
314 	 * active consumer (i.e., this is the first in perhaps
315 	 * a number of failures). If so, we then switch consumers
316 	 * to the next available consumer.
317 	 */
318 
319 	pbp = bp->bio_parent;
320 	gp = pbp->bio_to->geom;
321 	sc = gp->softc;
322 	cp = bp->bio_from;
323 	pp = cp->provider;
324 	cnt = (uintptr_t *)&cp->private;
325 
326 	mtx_lock(&sc->sc_mtx);
327 	if ((cp->index & MP_FAIL) == 0) {
328 		printf("GEOM_MULTIPATH: Error %d, %s in %s marked FAIL\n",
329 		    bp->bio_error, pp->name, sc->sc_name);
330 		g_multipath_fault(cp, MP_FAIL);
331 	}
332 	(*cnt)--;
333 	if (*cnt == 0 && (cp->index & (MP_LOST | MP_POSTED)) == MP_LOST) {
334 		cp->index |= MP_POSTED;
335 		mtx_unlock(&sc->sc_mtx);
336 		g_post_event(g_mpd, cp, M_WAITOK, NULL);
337 	} else
338 		mtx_unlock(&sc->sc_mtx);
339 
340 	/*
341 	 * If we can fruitfully restart the I/O, do so.
342 	 */
343 	if (pbp->bio_children < (uintptr_t)pbp->bio_driver1) {
344 		pbp->bio_inbed++;
345 		g_destroy_bio(bp);
346 		g_multipath_start(pbp);
347 	} else {
348 		g_std_done(bp);
349 	}
350 }
351 
352 static void
353 g_multipath_kt(void *arg)
354 {
355 
356 	g_multipath_kt_state = GKT_RUN;
357 	mtx_lock(&gmtbq_mtx);
358 	while (g_multipath_kt_state == GKT_RUN) {
359 		for (;;) {
360 			struct bio *bp;
361 
362 			bp = bioq_takefirst(&gmtbq);
363 			if (bp == NULL)
364 				break;
365 			mtx_unlock(&gmtbq_mtx);
366 			g_multipath_done_error(bp);
367 			mtx_lock(&gmtbq_mtx);
368 		}
369 		if (g_multipath_kt_state != GKT_RUN)
370 			break;
371 		msleep(&g_multipath_kt_state, &gmtbq_mtx, PRIBIO,
372 		    "gkt:wait", 0);
373 	}
374 	mtx_unlock(&gmtbq_mtx);
375 	wakeup(&g_multipath_kt_state);
376 	kproc_exit(0);
377 }
378 
379 
380 static int
381 g_multipath_access(struct g_provider *pp, int dr, int dw, int de)
382 {
383 	struct g_geom *gp;
384 	struct g_consumer *cp, *badcp = NULL;
385 	struct g_multipath_softc *sc;
386 	int error;
387 
388 	gp = pp->geom;
389 
390 	LIST_FOREACH(cp, &gp->consumer, consumer) {
391 		error = g_access(cp, dr, dw, de);
392 		if (error) {
393 			badcp = cp;
394 			goto fail;
395 		}
396 	}
397 	sc = gp->softc;
398 	sc->sc_opened += dr + dw + de;
399 	if (sc->sc_stopping && sc->sc_opened == 0)
400 		g_multipath_destroy(gp);
401 	return (0);
402 
403 fail:
404 	LIST_FOREACH(cp, &gp->consumer, consumer) {
405 		if (cp == badcp)
406 			break;
407 		(void) g_access(cp, -dr, -dw, -de);
408 	}
409 	return (error);
410 }
411 
412 static struct g_geom *
413 g_multipath_create(struct g_class *mp, struct g_multipath_metadata *md)
414 {
415 	struct g_multipath_softc *sc;
416 	struct g_geom *gp;
417 	struct g_provider *pp;
418 
419 	g_topology_assert();
420 
421 	LIST_FOREACH(gp, &mp->geom, geom) {
422 		sc = gp->softc;
423 		if (sc == NULL || sc->sc_stopping)
424 			continue;
425 		if (strcmp(gp->name, md->md_name) == 0) {
426 			printf("GEOM_MULTIPATH: name %s already exists\n",
427 			    md->md_name);
428 			return (NULL);
429 		}
430 	}
431 
432 	gp = g_new_geomf(mp, md->md_name);
433 	sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
434 	mtx_init(&sc->sc_mtx, "multipath", NULL, MTX_DEF);
435 	memcpy(sc->sc_uuid, md->md_uuid, sizeof (sc->sc_uuid));
436 	memcpy(sc->sc_name, md->md_name, sizeof (sc->sc_name));
437 	sc->sc_active_active = md->md_active_active;
438 	gp->softc = sc;
439 	gp->start = g_multipath_start;
440 	gp->orphan = g_multipath_orphan;
441 	gp->access = g_multipath_access;
442 	gp->dumpconf = g_multipath_dumpconf;
443 
444 	pp = g_new_providerf(gp, "multipath/%s", md->md_name);
445 	if (md->md_size != 0) {
446 		pp->mediasize = md->md_size -
447 		    ((md->md_uuid[0] != 0) ? md->md_sectorsize : 0);
448 		pp->sectorsize = md->md_sectorsize;
449 	}
450 	sc->sc_pp = pp;
451 	g_error_provider(pp, 0);
452 	printf("GEOM_MULTIPATH: %s created\n", gp->name);
453 	return (gp);
454 }
455 
456 static int
457 g_multipath_add_disk(struct g_geom *gp, struct g_provider *pp)
458 {
459 	struct g_multipath_softc *sc;
460 	struct g_consumer *cp, *nxtcp;
461 	int error, acr, acw, ace;
462 
463 	g_topology_assert();
464 
465 	sc = gp->softc;
466 	KASSERT(sc, ("no softc"));
467 
468 	/*
469 	 * Make sure that the passed provider isn't already attached
470 	 */
471 	LIST_FOREACH(cp, &gp->consumer, consumer) {
472 		if (cp->provider == pp)
473 			break;
474 	}
475 	if (cp) {
476 		printf("GEOM_MULTIPATH: provider %s already attached to %s\n",
477 		    pp->name, gp->name);
478 		return (EEXIST);
479 	}
480 	nxtcp = LIST_FIRST(&gp->consumer);
481 	cp = g_new_consumer(gp);
482 	cp->private = NULL;
483 	cp->index = MP_NEW;
484 	error = g_attach(cp, pp);
485 	if (error != 0) {
486 		printf("GEOM_MULTIPATH: cannot attach %s to %s",
487 		    pp->name, sc->sc_name);
488 		g_destroy_consumer(cp);
489 		return (error);
490 	}
491 
492 	/*
493 	 * Set access permissions on new consumer to match other consumers
494 	 */
495 	if (sc->sc_pp) {
496 		acr = sc->sc_pp->acr;
497 		acw = sc->sc_pp->acw;
498 		ace = sc->sc_pp->ace;
499 	} else
500 		acr = acw = ace = 0;
501 	if (g_multipath_exclusive) {
502 		acr++;
503 		acw++;
504 		ace++;
505 	}
506 	error = g_access(cp, acr, acw, ace);
507 	if (error) {
508 		printf("GEOM_MULTIPATH: cannot set access in "
509 		    "attaching %s to %s (%d)\n",
510 		    pp->name, sc->sc_name, error);
511 		g_detach(cp);
512 		g_destroy_consumer(cp);
513 		return (error);
514 	}
515 	if (sc->sc_pp != NULL && sc->sc_pp->mediasize == 0) {
516 		sc->sc_pp->mediasize = pp->mediasize -
517 		    ((sc->sc_uuid[0] != 0) ? pp->sectorsize : 0);
518 		sc->sc_pp->sectorsize = pp->sectorsize;
519 	}
520 	if (sc->sc_pp != NULL &&
521 	    sc->sc_pp->stripesize == 0 && sc->sc_pp->stripeoffset == 0) {
522 		sc->sc_pp->stripesize = pp->stripesize;
523 		sc->sc_pp->stripeoffset = pp->stripeoffset;
524 	}
525 	mtx_lock(&sc->sc_mtx);
526 	cp->index = 0;
527 	sc->sc_ndisks++;
528 	mtx_unlock(&sc->sc_mtx);
529 	printf("GEOM_MULTIPATH: %s added to %s\n",
530 	    pp->name, sc->sc_name);
531 	if (sc->sc_active == NULL) {
532 		sc->sc_active = cp;
533 		if (sc->sc_active_active != 1)
534 			printf("GEOM_MULTIPATH: %s is now active path in %s\n",
535 			    pp->name, sc->sc_name);
536 	}
537 	return (0);
538 }
539 
540 static int
541 g_multipath_destroy(struct g_geom *gp)
542 {
543 	struct g_multipath_softc *sc;
544 	struct g_consumer *cp, *cp1;
545 
546 	g_topology_assert();
547 	if (gp->softc == NULL)
548 		return (ENXIO);
549 	sc = gp->softc;
550 	if (!sc->sc_stopping) {
551 		printf("GEOM_MULTIPATH: destroying %s\n", gp->name);
552 		sc->sc_stopping = 1;
553 	}
554 	if (sc->sc_opened != 0) {
555 		if (sc->sc_pp != NULL) {
556 			g_wither_provider(sc->sc_pp, ENXIO);
557 			sc->sc_pp = NULL;
558 		}
559 		return (EINPROGRESS);
560 	}
561 	LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp1) {
562 		mtx_lock(&sc->sc_mtx);
563 		if ((cp->index & MP_POSTED) == 0) {
564 			cp->index |= MP_POSTED;
565 			mtx_unlock(&sc->sc_mtx);
566 			g_mpd(cp, 0);
567 			if (cp1 == NULL)
568 				return(0);	/* Recursion happened. */
569 		} else
570 			mtx_unlock(&sc->sc_mtx);
571 	}
572 	if (!LIST_EMPTY(&gp->consumer))
573 		return (EINPROGRESS);
574 	mtx_destroy(&sc->sc_mtx);
575 	g_free(gp->softc);
576 	gp->softc = NULL;
577 	printf("GEOM_MULTIPATH: %s destroyed\n", gp->name);
578 	g_wither_geom(gp, ENXIO);
579 	return (0);
580 }
581 
582 static int
583 g_multipath_destroy_geom(struct gctl_req *req, struct g_class *mp,
584     struct g_geom *gp)
585 {
586 
587 	return (g_multipath_destroy(gp));
588 }
589 
590 static int
591 g_multipath_rotate(struct g_geom *gp)
592 {
593 	struct g_consumer *lcp, *first_good_cp = NULL;
594 	struct g_multipath_softc *sc = gp->softc;
595 	int active_cp_seen = 0;
596 
597 	g_topology_assert();
598 	if (sc == NULL)
599 		return (ENXIO);
600 	LIST_FOREACH(lcp, &gp->consumer, consumer) {
601 		if ((lcp->index & MP_BAD) == 0) {
602 			if (first_good_cp == NULL)
603 				first_good_cp = lcp;
604 			if (active_cp_seen)
605 				break;
606 		}
607 		if (sc->sc_active == lcp)
608 			active_cp_seen = 1;
609 	}
610 	if (lcp == NULL)
611 		lcp = first_good_cp;
612 	if (lcp && lcp != sc->sc_active) {
613 		sc->sc_active = lcp;
614 		if (sc->sc_active_active != 1)
615 			printf("GEOM_MULTIPATH: %s is now active path in %s\n",
616 			    lcp->provider->name, sc->sc_name);
617 	}
618 	return (0);
619 }
620 
621 static void
622 g_multipath_init(struct g_class *mp)
623 {
624 	bioq_init(&gmtbq);
625 	mtx_init(&gmtbq_mtx, "gmtbq", NULL, MTX_DEF);
626 	kproc_create(g_multipath_kt, mp, NULL, 0, 0, "g_mp_kt");
627 }
628 
629 static void
630 g_multipath_fini(struct g_class *mp)
631 {
632 	if (g_multipath_kt_state == GKT_RUN) {
633 		mtx_lock(&gmtbq_mtx);
634 		g_multipath_kt_state = GKT_DIE;
635 		wakeup(&g_multipath_kt_state);
636 		msleep(&g_multipath_kt_state, &gmtbq_mtx, PRIBIO,
637 		    "gmp:fini", 0);
638 		mtx_unlock(&gmtbq_mtx);
639 	}
640 }
641 
642 static int
643 g_multipath_read_metadata(struct g_consumer *cp,
644     struct g_multipath_metadata *md)
645 {
646 	struct g_provider *pp;
647 	u_char *buf;
648 	int error;
649 
650 	g_topology_assert();
651 	error = g_access(cp, 1, 0, 0);
652 	if (error != 0)
653 		return (error);
654 	pp = cp->provider;
655 	g_topology_unlock();
656 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize,
657 	    pp->sectorsize, &error);
658 	g_topology_lock();
659 	g_access(cp, -1, 0, 0);
660 	if (buf == NULL)
661 		return (error);
662 	multipath_metadata_decode(buf, md);
663 	g_free(buf);
664 	return (0);
665 }
666 
667 static struct g_geom *
668 g_multipath_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
669 {
670 	struct g_multipath_metadata md;
671 	struct g_multipath_softc *sc;
672 	struct g_consumer *cp;
673 	struct g_geom *gp, *gp1;
674 	int error, isnew;
675 
676 	g_topology_assert();
677 
678 	gp = g_new_geomf(mp, "multipath:taste");
679 	gp->start = g_multipath_start;
680 	gp->access = g_multipath_access;
681 	gp->orphan = g_multipath_orphan;
682 	cp = g_new_consumer(gp);
683 	g_attach(cp, pp);
684 	error = g_multipath_read_metadata(cp, &md);
685 	g_detach(cp);
686 	g_destroy_consumer(cp);
687 	g_destroy_geom(gp);
688 	if (error != 0)
689 		return (NULL);
690 	gp = NULL;
691 
692 	if (strcmp(md.md_magic, G_MULTIPATH_MAGIC) != 0) {
693 		if (g_multipath_debug)
694 			printf("%s is not MULTIPATH\n", pp->name);
695 		return (NULL);
696 	}
697 	if (md.md_version != G_MULTIPATH_VERSION) {
698 		printf("%s has version %d multipath id- this module is version "
699 		    " %d: rejecting\n", pp->name, md.md_version,
700 		    G_MULTIPATH_VERSION);
701 		return (NULL);
702 	}
703 	if (md.md_size != 0 && md.md_size != pp->mediasize)
704 		return (NULL);
705 	if (md.md_sectorsize != 0 && md.md_sectorsize != pp->sectorsize)
706 		return (NULL);
707 	if (g_multipath_debug)
708 		printf("MULTIPATH: %s/%s\n", md.md_name, md.md_uuid);
709 
710 	/*
711 	 * Let's check if such a device already is present. We check against
712 	 * uuid alone first because that's the true distinguishor. If that
713 	 * passes, then we check for name conflicts. If there are conflicts,
714 	 * modify the name.
715 	 *
716 	 * The whole purpose of this is to solve the problem that people don't
717 	 * pick good unique names, but good unique names (like uuids) are a
718 	 * pain to use. So, we allow people to build GEOMs with friendly names
719 	 * and uuids, and modify the names in case there's a collision.
720 	 */
721 	sc = NULL;
722 	LIST_FOREACH(gp, &mp->geom, geom) {
723 		sc = gp->softc;
724 		if (sc == NULL || sc->sc_stopping)
725 			continue;
726 		if (strncmp(md.md_uuid, sc->sc_uuid, sizeof(md.md_uuid)) == 0)
727 			break;
728 	}
729 
730 	LIST_FOREACH(gp1, &mp->geom, geom) {
731 		if (gp1 == gp)
732 			continue;
733 		sc = gp1->softc;
734 		if (sc == NULL || sc->sc_stopping)
735 			continue;
736 		if (strncmp(md.md_name, sc->sc_name, sizeof(md.md_name)) == 0)
737 			break;
738 	}
739 
740 	/*
741 	 * If gp is NULL, we had no extant MULTIPATH geom with this uuid.
742 	 *
743 	 * If gp1 is *not* NULL, that means we have a MULTIPATH geom extant
744 	 * with the same name (but a different UUID).
745 	 *
746 	 * If gp is NULL, then modify the name with a random number and
747   	 * complain, but allow the creation of the geom to continue.
748 	 *
749 	 * If gp is *not* NULL, just use the geom's name as we're attaching
750 	 * this disk to the (previously generated) name.
751 	 */
752 
753 	if (gp1) {
754 		sc = gp1->softc;
755 		if (gp == NULL) {
756 			char buf[16];
757 			u_long rand = random();
758 
759 			snprintf(buf, sizeof (buf), "%s-%lu", md.md_name, rand);
760 			printf("GEOM_MULTIPATH: geom %s/%s exists already\n",
761 			    sc->sc_name, sc->sc_uuid);
762 			printf("GEOM_MULTIPATH: %s will be (temporarily) %s\n",
763 			    md.md_uuid, buf);
764 			strlcpy(md.md_name, buf, sizeof(md.md_name));
765 		} else {
766 			strlcpy(md.md_name, sc->sc_name, sizeof(md.md_name));
767 		}
768 	}
769 
770 	if (gp == NULL) {
771 		gp = g_multipath_create(mp, &md);
772 		if (gp == NULL) {
773 			printf("GEOM_MULTIPATH: cannot create geom %s/%s\n",
774 			    md.md_name, md.md_uuid);
775 			return (NULL);
776 		}
777 		isnew = 1;
778 	} else {
779 		isnew = 0;
780 	}
781 
782 	sc = gp->softc;
783 	KASSERT(sc != NULL, ("sc is NULL"));
784 	error = g_multipath_add_disk(gp, pp);
785 	if (error != 0) {
786 		if (isnew)
787 			g_multipath_destroy(gp);
788 		return (NULL);
789 	}
790 	return (gp);
791 }
792 
793 static void
794 g_multipath_ctl_add_name(struct gctl_req *req, struct g_class *mp,
795     const char *name)
796 {
797 	struct g_multipath_softc *sc;
798 	struct g_geom *gp;
799 	struct g_consumer *cp;
800 	struct g_provider *pp;
801 	const char *mpname;
802 	static const char devpf[6] = "/dev/";
803 
804 	g_topology_assert();
805 
806 	mpname = gctl_get_asciiparam(req, "arg0");
807         if (mpname == NULL) {
808                 gctl_error(req, "No 'arg0' argument");
809                 return;
810         }
811 	gp = g_multipath_find_geom(mp, mpname);
812 	if (gp == NULL) {
813 		gctl_error(req, "Device %s is invalid", mpname);
814 		return;
815 	}
816 	sc = gp->softc;
817 
818 	if (strncmp(name, devpf, 5) == 0)
819 		name += 5;
820 	pp = g_provider_by_name(name);
821 	if (pp == NULL) {
822 		gctl_error(req, "Provider %s is invalid", name);
823 		return;
824 	}
825 
826 	/*
827 	 * Check to make sure parameters match.
828 	 */
829 	LIST_FOREACH(cp, &gp->consumer, consumer) {
830 		if (cp->provider == pp) {
831 			gctl_error(req, "provider %s is already there",
832 			    pp->name);
833 			return;
834 		}
835 	}
836 	if (sc->sc_pp != NULL && sc->sc_pp->mediasize != 0 &&
837 	    sc->sc_pp->mediasize + (sc->sc_uuid[0] != 0 ? pp->sectorsize : 0)
838 	     != pp->mediasize) {
839 		gctl_error(req, "Providers size mismatch %jd != %jd",
840 		    (intmax_t) sc->sc_pp->mediasize +
841 			(sc->sc_uuid[0] != 0 ? pp->sectorsize : 0),
842 		    (intmax_t) pp->mediasize);
843 		return;
844 	}
845 	if (sc->sc_pp != NULL && sc->sc_pp->sectorsize != 0 &&
846 	    sc->sc_pp->sectorsize != pp->sectorsize) {
847 		gctl_error(req, "Providers sectorsize mismatch %u != %u",
848 		    sc->sc_pp->sectorsize, pp->sectorsize);
849 		return;
850 	}
851 
852 	/*
853 	 * Now add....
854 	 */
855 	(void) g_multipath_add_disk(gp, pp);
856 }
857 
858 static void
859 g_multipath_ctl_prefer(struct gctl_req *req, struct g_class *mp)
860 {
861 	struct g_geom *gp;
862 	struct g_multipath_softc *sc;
863 	struct g_consumer *cp;
864 	const char *name, *mpname;
865 	static const char devpf[6] = "/dev/";
866 	int *nargs;
867 
868 	g_topology_assert();
869 
870 	mpname = gctl_get_asciiparam(req, "arg0");
871         if (mpname == NULL) {
872                 gctl_error(req, "No 'arg0' argument");
873                 return;
874         }
875 	gp = g_multipath_find_geom(mp, mpname);
876 	if (gp == NULL) {
877 		gctl_error(req, "Device %s is invalid", mpname);
878 		return;
879 	}
880 	sc = gp->softc;
881 
882 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
883 	if (nargs == NULL) {
884 		gctl_error(req, "No 'nargs' argument");
885 		return;
886 	}
887 	if (*nargs != 2) {
888 		gctl_error(req, "missing device");
889 		return;
890 	}
891 
892 	name = gctl_get_asciiparam(req, "arg1");
893 	if (name == NULL) {
894 		gctl_error(req, "No 'arg1' argument");
895 		return;
896 	}
897 	if (strncmp(name, devpf, 5) == 0) {
898 		name += 5;
899 	}
900 
901 	LIST_FOREACH(cp, &gp->consumer, consumer) {
902 		if (cp->provider != NULL
903                       && strcmp(cp->provider->name, name) == 0)
904 		    break;
905 	}
906 
907 	if (cp == NULL) {
908 		gctl_error(req, "Provider %s not found", name);
909 		return;
910 	}
911 
912 	mtx_lock(&sc->sc_mtx);
913 
914 	if (cp->index & MP_BAD) {
915 		gctl_error(req, "Consumer %s is invalid", name);
916 		mtx_unlock(&sc->sc_mtx);
917 		return;
918 	}
919 
920 	/* Here when the consumer is present and in good shape */
921 
922 	sc->sc_active = cp;
923 	if (!sc->sc_active_active)
924 	    printf("GEOM_MULTIPATH: %s now active path in %s\n",
925 		sc->sc_active->provider->name, sc->sc_name);
926 
927 	mtx_unlock(&sc->sc_mtx);
928 }
929 
930 static void
931 g_multipath_ctl_add(struct gctl_req *req, struct g_class *mp)
932 {
933 	struct g_multipath_softc *sc;
934 	struct g_geom *gp;
935 	const char *mpname, *name;
936 
937 	mpname = gctl_get_asciiparam(req, "arg0");
938         if (mpname == NULL) {
939                 gctl_error(req, "No 'arg0' argument");
940                 return;
941         }
942 	gp = g_multipath_find_geom(mp, mpname);
943 	if (gp == NULL) {
944 		gctl_error(req, "Device %s not found", mpname);
945 		return;
946 	}
947 	sc = gp->softc;
948 
949 	name = gctl_get_asciiparam(req, "arg1");
950 	if (name == NULL) {
951 		gctl_error(req, "No 'arg1' argument");
952 		return;
953 	}
954 	g_multipath_ctl_add_name(req, mp, name);
955 }
956 
957 static void
958 g_multipath_ctl_create(struct gctl_req *req, struct g_class *mp)
959 {
960 	struct g_multipath_metadata md;
961 	struct g_multipath_softc *sc;
962 	struct g_geom *gp;
963 	const char *mpname, *name;
964 	char param[16];
965 	int *nargs, i, *val;
966 
967 	g_topology_assert();
968 
969 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
970 	if (*nargs < 2) {
971 		gctl_error(req, "wrong number of arguments.");
972 		return;
973 	}
974 
975 	mpname = gctl_get_asciiparam(req, "arg0");
976         if (mpname == NULL) {
977                 gctl_error(req, "No 'arg0' argument");
978                 return;
979         }
980 	gp = g_multipath_find_geom(mp, mpname);
981 	if (gp != NULL) {
982 		gctl_error(req, "Device %s already exist", mpname);
983 		return;
984 	}
985 	sc = gp->softc;
986 
987 	memset(&md, 0, sizeof(md));
988 	strlcpy(md.md_magic, G_MULTIPATH_MAGIC, sizeof(md.md_magic));
989 	md.md_version = G_MULTIPATH_VERSION;
990 	strlcpy(md.md_name, mpname, sizeof(md.md_name));
991 	md.md_size = 0;
992 	md.md_sectorsize = 0;
993 	md.md_uuid[0] = 0;
994 	md.md_active_active = 0;
995 	val = gctl_get_paraml(req, "active_active", sizeof(*val));
996 	if (val != NULL && *val != 0)
997 		md.md_active_active = 1;
998 	val = gctl_get_paraml(req, "active_read", sizeof(*val));
999 	if (val != NULL && *val != 0)
1000 		md.md_active_active = 2;
1001 	gp = g_multipath_create(mp, &md);
1002 	if (gp == NULL) {
1003 		gctl_error(req, "GEOM_MULTIPATH: cannot create geom %s/%s\n",
1004 		    md.md_name, md.md_uuid);
1005 		return;
1006 	}
1007 	sc = gp->softc;
1008 
1009 	for (i = 1; i < *nargs; i++) {
1010 		snprintf(param, sizeof(param), "arg%d", i);
1011 		name = gctl_get_asciiparam(req, param);
1012 		g_multipath_ctl_add_name(req, mp, name);
1013 	}
1014 
1015 	if (sc->sc_ndisks != (*nargs - 1))
1016 		g_multipath_destroy(gp);
1017 }
1018 
1019 static void
1020 g_multipath_ctl_configure(struct gctl_req *req, struct g_class *mp)
1021 {
1022 	struct g_multipath_softc *sc;
1023 	struct g_geom *gp;
1024 	struct g_consumer *cp;
1025 	struct g_provider *pp;
1026 	struct g_multipath_metadata md;
1027 	const char *name;
1028 	int error, *val;
1029 	void *buf;
1030 
1031 	g_topology_assert();
1032 
1033 	name = gctl_get_asciiparam(req, "arg0");
1034 	if (name == NULL) {
1035 		gctl_error(req, "No 'arg0' argument");
1036 		return;
1037 	}
1038 	gp = g_multipath_find_geom(mp, name);
1039 	if (gp == NULL) {
1040 		gctl_error(req, "Device %s is invalid", name);
1041 		return;
1042 	}
1043 	sc = gp->softc;
1044 	val = gctl_get_paraml(req, "active_active", sizeof(*val));
1045 	if (val != NULL && *val != 0)
1046 		sc->sc_active_active = 1;
1047 	val = gctl_get_paraml(req, "active_read", sizeof(*val));
1048 	if (val != NULL && *val != 0)
1049 		sc->sc_active_active = 2;
1050 	val = gctl_get_paraml(req, "active_passive", sizeof(*val));
1051 	if (val != NULL && *val != 0)
1052 		sc->sc_active_active = 0;
1053 	if (sc->sc_uuid[0] != 0 && sc->sc_active != NULL) {
1054 		cp = sc->sc_active;
1055 		pp = cp->provider;
1056 		error = g_access(cp, 1, 1, 1);
1057 		if (error != 0) {
1058 			gctl_error(req, "Can't open %s (%d)", pp->name, error);
1059 			return;
1060 		}
1061 		g_topology_unlock();
1062 		buf = g_malloc(pp->sectorsize, M_WAITOK | M_ZERO);
1063 		strlcpy(md.md_magic, G_MULTIPATH_MAGIC, sizeof(md.md_magic));
1064 		memcpy(md.md_uuid, sc->sc_uuid, sizeof (sc->sc_uuid));
1065 		strlcpy(md.md_name, name, sizeof(md.md_name));
1066 		md.md_version = G_MULTIPATH_VERSION;
1067 		md.md_size = pp->mediasize;
1068 		md.md_sectorsize = pp->sectorsize;
1069 		md.md_active_active = sc->sc_active_active;
1070 		multipath_metadata_encode(&md, buf);
1071 		error = g_write_data(cp, pp->mediasize - pp->sectorsize,
1072 		    buf, pp->sectorsize);
1073 		g_topology_lock();
1074 		g_access(cp, -1, -1, -1);
1075 		if (error != 0)
1076 			gctl_error(req, "Can't update metadata on %s (%d)",
1077 			    pp->name, error);
1078 	}
1079 }
1080 
1081 static void
1082 g_multipath_ctl_fail(struct gctl_req *req, struct g_class *mp, int fail)
1083 {
1084 	struct g_multipath_softc *sc;
1085 	struct g_geom *gp;
1086 	struct g_consumer *cp;
1087 	const char *mpname, *name;
1088 	int found;
1089 
1090 	mpname = gctl_get_asciiparam(req, "arg0");
1091         if (mpname == NULL) {
1092                 gctl_error(req, "No 'arg0' argument");
1093                 return;
1094         }
1095 	gp = g_multipath_find_geom(mp, mpname);
1096 	if (gp == NULL) {
1097 		gctl_error(req, "Device %s not found", mpname);
1098 		return;
1099 	}
1100 	sc = gp->softc;
1101 
1102 	name = gctl_get_asciiparam(req, "arg1");
1103 	if (name == NULL) {
1104 		gctl_error(req, "No 'arg1' argument");
1105 		return;
1106 	}
1107 
1108 	found = 0;
1109 	mtx_lock(&sc->sc_mtx);
1110 	LIST_FOREACH(cp, &gp->consumer, consumer) {
1111 		if (cp->provider != NULL &&
1112 		    strcmp(cp->provider->name, name) == 0 &&
1113 		    (cp->index & MP_LOST) == 0) {
1114 			found = 1;
1115 			if (!fail == !(cp->index & MP_FAIL))
1116 				continue;
1117 			printf("GEOM_MULTIPATH: %s in %s is marked %s.\n",
1118 				name, sc->sc_name, fail ? "FAIL" : "OK");
1119 			if (fail) {
1120 				g_multipath_fault(cp, MP_FAIL);
1121 			} else {
1122 				cp->index &= ~MP_FAIL;
1123 			}
1124 		}
1125 	}
1126 	mtx_unlock(&sc->sc_mtx);
1127 	if (found == 0)
1128 		gctl_error(req, "Provider %s not found", name);
1129 }
1130 
1131 static void
1132 g_multipath_ctl_remove(struct gctl_req *req, struct g_class *mp)
1133 {
1134 	struct g_multipath_softc *sc;
1135 	struct g_geom *gp;
1136 	struct g_consumer *cp, *cp1;
1137 	const char *mpname, *name;
1138 	uintptr_t *cnt;
1139 	int found;
1140 
1141 	mpname = gctl_get_asciiparam(req, "arg0");
1142         if (mpname == NULL) {
1143                 gctl_error(req, "No 'arg0' argument");
1144                 return;
1145         }
1146 	gp = g_multipath_find_geom(mp, mpname);
1147 	if (gp == NULL) {
1148 		gctl_error(req, "Device %s not found", mpname);
1149 		return;
1150 	}
1151 	sc = gp->softc;
1152 
1153 	name = gctl_get_asciiparam(req, "arg1");
1154 	if (name == NULL) {
1155 		gctl_error(req, "No 'arg1' argument");
1156 		return;
1157 	}
1158 
1159 	found = 0;
1160 	mtx_lock(&sc->sc_mtx);
1161 	LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp1) {
1162 		if (cp->provider != NULL &&
1163 		    strcmp(cp->provider->name, name) == 0 &&
1164 		    (cp->index & MP_LOST) == 0) {
1165 			found = 1;
1166 			printf("GEOM_MULTIPATH: removing %s from %s\n",
1167 			    cp->provider->name, cp->geom->name);
1168 			sc->sc_ndisks--;
1169 			g_multipath_fault(cp, MP_LOST);
1170 			cnt = (uintptr_t *)&cp->private;
1171 			if (*cnt == 0 && (cp->index & MP_POSTED) == 0) {
1172 				cp->index |= MP_POSTED;
1173 				mtx_unlock(&sc->sc_mtx);
1174 				g_mpd(cp, 0);
1175 				if (cp1 == NULL)
1176 					return;	/* Recursion happened. */
1177 				mtx_lock(&sc->sc_mtx);
1178 			}
1179 		}
1180 	}
1181 	mtx_unlock(&sc->sc_mtx);
1182 	if (found == 0)
1183 		gctl_error(req, "Provider %s not found", name);
1184 }
1185 
1186 static struct g_geom *
1187 g_multipath_find_geom(struct g_class *mp, const char *name)
1188 {
1189 	struct g_geom *gp;
1190 	struct g_multipath_softc *sc;
1191 
1192 	LIST_FOREACH(gp, &mp->geom, geom) {
1193 		sc = gp->softc;
1194 		if (sc == NULL || sc->sc_stopping)
1195 			continue;
1196 		if (strcmp(gp->name, name) == 0)
1197 			return (gp);
1198 	}
1199 	return (NULL);
1200 }
1201 
1202 static void
1203 g_multipath_ctl_stop(struct gctl_req *req, struct g_class *mp)
1204 {
1205 	struct g_geom *gp;
1206 	const char *name;
1207 	int error;
1208 
1209 	g_topology_assert();
1210 
1211 	name = gctl_get_asciiparam(req, "arg0");
1212         if (name == NULL) {
1213                 gctl_error(req, "No 'arg0' argument");
1214                 return;
1215         }
1216 	gp = g_multipath_find_geom(mp, name);
1217 	if (gp == NULL) {
1218 		gctl_error(req, "Device %s is invalid", name);
1219 		return;
1220 	}
1221 	error = g_multipath_destroy(gp);
1222 	if (error != 0 && error != EINPROGRESS)
1223 		gctl_error(req, "failed to stop %s (err=%d)", name, error);
1224 }
1225 
1226 static void
1227 g_multipath_ctl_destroy(struct gctl_req *req, struct g_class *mp)
1228 {
1229 	struct g_geom *gp;
1230 	struct g_multipath_softc *sc;
1231 	struct g_consumer *cp;
1232 	struct g_provider *pp;
1233 	const char *name;
1234 	uint8_t *buf;
1235 	int error;
1236 
1237 	g_topology_assert();
1238 
1239 	name = gctl_get_asciiparam(req, "arg0");
1240         if (name == NULL) {
1241                 gctl_error(req, "No 'arg0' argument");
1242                 return;
1243         }
1244 	gp = g_multipath_find_geom(mp, name);
1245 	if (gp == NULL) {
1246 		gctl_error(req, "Device %s is invalid", name);
1247 		return;
1248 	}
1249 	sc = gp->softc;
1250 
1251 	if (sc->sc_uuid[0] != 0 && sc->sc_active != NULL) {
1252 		cp = sc->sc_active;
1253 		pp = cp->provider;
1254 		error = g_access(cp, 1, 1, 1);
1255 		if (error != 0) {
1256 			gctl_error(req, "Can't open %s (%d)", pp->name, error);
1257 			goto destroy;
1258 		}
1259 		g_topology_unlock();
1260 		buf = g_malloc(pp->sectorsize, M_WAITOK | M_ZERO);
1261 		error = g_write_data(cp, pp->mediasize - pp->sectorsize,
1262 		    buf, pp->sectorsize);
1263 		g_topology_lock();
1264 		g_access(cp, -1, -1, -1);
1265 		if (error != 0)
1266 			gctl_error(req, "Can't erase metadata on %s (%d)",
1267 			    pp->name, error);
1268 	}
1269 
1270 destroy:
1271 	error = g_multipath_destroy(gp);
1272 	if (error != 0 && error != EINPROGRESS)
1273 		gctl_error(req, "failed to destroy %s (err=%d)", name, error);
1274 }
1275 
1276 static void
1277 g_multipath_ctl_rotate(struct gctl_req *req, struct g_class *mp)
1278 {
1279 	struct g_geom *gp;
1280 	const char *name;
1281 	int error;
1282 
1283 	g_topology_assert();
1284 
1285 	name = gctl_get_asciiparam(req, "arg0");
1286         if (name == NULL) {
1287                 gctl_error(req, "No 'arg0' argument");
1288                 return;
1289         }
1290 	gp = g_multipath_find_geom(mp, name);
1291 	if (gp == NULL) {
1292 		gctl_error(req, "Device %s is invalid", name);
1293 		return;
1294 	}
1295 	error = g_multipath_rotate(gp);
1296 	if (error != 0) {
1297 		gctl_error(req, "failed to rotate %s (err=%d)", name, error);
1298 	}
1299 }
1300 
1301 static void
1302 g_multipath_ctl_getactive(struct gctl_req *req, struct g_class *mp)
1303 {
1304 	struct sbuf *sb;
1305 	struct g_geom *gp;
1306 	struct g_multipath_softc *sc;
1307 	struct g_consumer *cp;
1308 	const char *name;
1309 	int empty;
1310 
1311 	sb = sbuf_new_auto();
1312 
1313 	g_topology_assert();
1314 	name = gctl_get_asciiparam(req, "arg0");
1315         if (name == NULL) {
1316                 gctl_error(req, "No 'arg0' argument");
1317                 return;
1318         }
1319 	gp = g_multipath_find_geom(mp, name);
1320 	if (gp == NULL) {
1321 		gctl_error(req, "Device %s is invalid", name);
1322 		return;
1323 	}
1324 	sc = gp->softc;
1325 	if (sc->sc_active_active == 1) {
1326 		empty = 1;
1327 		LIST_FOREACH(cp, &gp->consumer, consumer) {
1328 			if (cp->index & MP_BAD)
1329 				continue;
1330 			if (!empty)
1331 				sbuf_cat(sb, " ");
1332 			sbuf_cat(sb, cp->provider->name);
1333 			empty = 0;
1334 		}
1335 		if (empty)
1336 			sbuf_cat(sb, "none");
1337 		sbuf_cat(sb, "\n");
1338 	} else if (sc->sc_active && sc->sc_active->provider) {
1339 		sbuf_printf(sb, "%s\n", sc->sc_active->provider->name);
1340 	} else {
1341 		sbuf_printf(sb, "none\n");
1342 	}
1343 	sbuf_finish(sb);
1344 	gctl_set_param_err(req, "output", sbuf_data(sb), sbuf_len(sb) + 1);
1345 	sbuf_delete(sb);
1346 }
1347 
1348 static void
1349 g_multipath_config(struct gctl_req *req, struct g_class *mp, const char *verb)
1350 {
1351 	uint32_t *version;
1352 	g_topology_assert();
1353 	version = gctl_get_paraml(req, "version", sizeof(*version));
1354 	if (version == NULL) {
1355 		gctl_error(req, "No 'version' argument");
1356 	} else if (*version != G_MULTIPATH_VERSION) {
1357 		gctl_error(req, "Userland and kernel parts are out of sync");
1358 	} else if (strcmp(verb, "add") == 0) {
1359 		g_multipath_ctl_add(req, mp);
1360 	} else if (strcmp(verb, "prefer") == 0) {
1361 		g_multipath_ctl_prefer(req, mp);
1362 	} else if (strcmp(verb, "create") == 0) {
1363 		g_multipath_ctl_create(req, mp);
1364 	} else if (strcmp(verb, "configure") == 0) {
1365 		g_multipath_ctl_configure(req, mp);
1366 	} else if (strcmp(verb, "stop") == 0) {
1367 		g_multipath_ctl_stop(req, mp);
1368 	} else if (strcmp(verb, "destroy") == 0) {
1369 		g_multipath_ctl_destroy(req, mp);
1370 	} else if (strcmp(verb, "fail") == 0) {
1371 		g_multipath_ctl_fail(req, mp, 1);
1372 	} else if (strcmp(verb, "restore") == 0) {
1373 		g_multipath_ctl_fail(req, mp, 0);
1374 	} else if (strcmp(verb, "remove") == 0) {
1375 		g_multipath_ctl_remove(req, mp);
1376 	} else if (strcmp(verb, "rotate") == 0) {
1377 		g_multipath_ctl_rotate(req, mp);
1378 	} else if (strcmp(verb, "getactive") == 0) {
1379 		g_multipath_ctl_getactive(req, mp);
1380 	} else {
1381 		gctl_error(req, "Unknown verb %s", verb);
1382 	}
1383 }
1384 
1385 static void
1386 g_multipath_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
1387     struct g_consumer *cp, struct g_provider *pp)
1388 {
1389 	struct g_multipath_softc *sc;
1390 	int good;
1391 
1392 	g_topology_assert();
1393 
1394 	sc = gp->softc;
1395 	if (sc == NULL)
1396 		return;
1397 	if (cp != NULL) {
1398 		sbuf_printf(sb, "%s<State>%s</State>\n", indent,
1399 		    (cp->index & MP_NEW) ? "NEW" :
1400 		    (cp->index & MP_LOST) ? "LOST" :
1401 		    (cp->index & MP_FAIL) ? "FAIL" :
1402 		    (sc->sc_active_active == 1 || sc->sc_active == cp) ?
1403 		     "ACTIVE" :
1404 		     sc->sc_active_active == 2 ? "READ" : "PASSIVE");
1405 	} else {
1406 		good = g_multipath_good(gp);
1407 		sbuf_printf(sb, "%s<State>%s</State>\n", indent,
1408 		    good == 0 ? "BROKEN" :
1409 		    (good != sc->sc_ndisks || sc->sc_ndisks == 1) ?
1410 		    "DEGRADED" : "OPTIMAL");
1411 	}
1412 	if (cp == NULL && pp == NULL) {
1413 		sbuf_printf(sb, "%s<UUID>%s</UUID>\n", indent, sc->sc_uuid);
1414 		sbuf_printf(sb, "%s<Mode>Active/%s</Mode>\n", indent,
1415 		    sc->sc_active_active == 2 ? "Read" :
1416 		    sc->sc_active_active == 1 ? "Active" : "Passive");
1417 		sbuf_printf(sb, "%s<Type>%s</Type>\n", indent,
1418 		    sc->sc_uuid[0] == 0 ? "MANUAL" : "AUTOMATIC");
1419 	}
1420 }
1421 
1422 DECLARE_GEOM_CLASS(g_multipath_class, g_multipath);
1423