xref: /freebsd/sys/geom/multipath/g_multipath.c (revision 09d325677d53a12c79a43664ff29871e92247629)
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, "%s", 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 	pp->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE;
446 	if (md->md_size != 0) {
447 		pp->mediasize = md->md_size -
448 		    ((md->md_uuid[0] != 0) ? md->md_sectorsize : 0);
449 		pp->sectorsize = md->md_sectorsize;
450 	}
451 	sc->sc_pp = pp;
452 	g_error_provider(pp, 0);
453 	printf("GEOM_MULTIPATH: %s created\n", gp->name);
454 	return (gp);
455 }
456 
457 static int
458 g_multipath_add_disk(struct g_geom *gp, struct g_provider *pp)
459 {
460 	struct g_multipath_softc *sc;
461 	struct g_consumer *cp, *nxtcp;
462 	int error, acr, acw, ace;
463 
464 	g_topology_assert();
465 
466 	sc = gp->softc;
467 	KASSERT(sc, ("no softc"));
468 
469 	/*
470 	 * Make sure that the passed provider isn't already attached
471 	 */
472 	LIST_FOREACH(cp, &gp->consumer, consumer) {
473 		if (cp->provider == pp)
474 			break;
475 	}
476 	if (cp) {
477 		printf("GEOM_MULTIPATH: provider %s already attached to %s\n",
478 		    pp->name, gp->name);
479 		return (EEXIST);
480 	}
481 	nxtcp = LIST_FIRST(&gp->consumer);
482 	cp = g_new_consumer(gp);
483 	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
484 	cp->private = NULL;
485 	cp->index = MP_NEW;
486 	error = g_attach(cp, pp);
487 	if (error != 0) {
488 		printf("GEOM_MULTIPATH: cannot attach %s to %s",
489 		    pp->name, sc->sc_name);
490 		g_destroy_consumer(cp);
491 		return (error);
492 	}
493 
494 	/*
495 	 * Set access permissions on new consumer to match other consumers
496 	 */
497 	if (sc->sc_pp) {
498 		acr = sc->sc_pp->acr;
499 		acw = sc->sc_pp->acw;
500 		ace = sc->sc_pp->ace;
501 	} else
502 		acr = acw = ace = 0;
503 	if (g_multipath_exclusive) {
504 		acr++;
505 		acw++;
506 		ace++;
507 	}
508 	error = g_access(cp, acr, acw, ace);
509 	if (error) {
510 		printf("GEOM_MULTIPATH: cannot set access in "
511 		    "attaching %s to %s (%d)\n",
512 		    pp->name, sc->sc_name, error);
513 		g_detach(cp);
514 		g_destroy_consumer(cp);
515 		return (error);
516 	}
517 	if (sc->sc_pp != NULL && sc->sc_pp->mediasize == 0) {
518 		sc->sc_pp->mediasize = pp->mediasize -
519 		    ((sc->sc_uuid[0] != 0) ? pp->sectorsize : 0);
520 		sc->sc_pp->sectorsize = pp->sectorsize;
521 	}
522 	if (sc->sc_pp != NULL &&
523 	    sc->sc_pp->stripesize == 0 && sc->sc_pp->stripeoffset == 0) {
524 		sc->sc_pp->stripesize = pp->stripesize;
525 		sc->sc_pp->stripeoffset = pp->stripeoffset;
526 	}
527 	if (sc->sc_pp != NULL)
528 		sc->sc_pp->flags |= pp->flags & G_PF_ACCEPT_UNMAPPED;
529 	mtx_lock(&sc->sc_mtx);
530 	cp->index = 0;
531 	sc->sc_ndisks++;
532 	mtx_unlock(&sc->sc_mtx);
533 	printf("GEOM_MULTIPATH: %s added to %s\n",
534 	    pp->name, sc->sc_name);
535 	if (sc->sc_active == NULL) {
536 		sc->sc_active = cp;
537 		if (sc->sc_active_active != 1)
538 			printf("GEOM_MULTIPATH: %s is now active path in %s\n",
539 			    pp->name, sc->sc_name);
540 	}
541 	return (0);
542 }
543 
544 static int
545 g_multipath_destroy(struct g_geom *gp)
546 {
547 	struct g_multipath_softc *sc;
548 	struct g_consumer *cp, *cp1;
549 
550 	g_topology_assert();
551 	if (gp->softc == NULL)
552 		return (ENXIO);
553 	sc = gp->softc;
554 	if (!sc->sc_stopping) {
555 		printf("GEOM_MULTIPATH: destroying %s\n", gp->name);
556 		sc->sc_stopping = 1;
557 	}
558 	if (sc->sc_opened != 0) {
559 		if (sc->sc_pp != NULL) {
560 			g_wither_provider(sc->sc_pp, ENXIO);
561 			sc->sc_pp = NULL;
562 		}
563 		return (EINPROGRESS);
564 	}
565 	LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp1) {
566 		mtx_lock(&sc->sc_mtx);
567 		if ((cp->index & MP_POSTED) == 0) {
568 			cp->index |= MP_POSTED;
569 			mtx_unlock(&sc->sc_mtx);
570 			g_mpd(cp, 0);
571 			if (cp1 == NULL)
572 				return(0);	/* Recursion happened. */
573 		} else
574 			mtx_unlock(&sc->sc_mtx);
575 	}
576 	if (!LIST_EMPTY(&gp->consumer))
577 		return (EINPROGRESS);
578 	mtx_destroy(&sc->sc_mtx);
579 	g_free(gp->softc);
580 	gp->softc = NULL;
581 	printf("GEOM_MULTIPATH: %s destroyed\n", gp->name);
582 	g_wither_geom(gp, ENXIO);
583 	return (0);
584 }
585 
586 static int
587 g_multipath_destroy_geom(struct gctl_req *req, struct g_class *mp,
588     struct g_geom *gp)
589 {
590 
591 	return (g_multipath_destroy(gp));
592 }
593 
594 static int
595 g_multipath_rotate(struct g_geom *gp)
596 {
597 	struct g_consumer *lcp, *first_good_cp = NULL;
598 	struct g_multipath_softc *sc = gp->softc;
599 	int active_cp_seen = 0;
600 
601 	g_topology_assert();
602 	if (sc == NULL)
603 		return (ENXIO);
604 	LIST_FOREACH(lcp, &gp->consumer, consumer) {
605 		if ((lcp->index & MP_BAD) == 0) {
606 			if (first_good_cp == NULL)
607 				first_good_cp = lcp;
608 			if (active_cp_seen)
609 				break;
610 		}
611 		if (sc->sc_active == lcp)
612 			active_cp_seen = 1;
613 	}
614 	if (lcp == NULL)
615 		lcp = first_good_cp;
616 	if (lcp && lcp != sc->sc_active) {
617 		sc->sc_active = lcp;
618 		if (sc->sc_active_active != 1)
619 			printf("GEOM_MULTIPATH: %s is now active path in %s\n",
620 			    lcp->provider->name, sc->sc_name);
621 	}
622 	return (0);
623 }
624 
625 static void
626 g_multipath_init(struct g_class *mp)
627 {
628 	bioq_init(&gmtbq);
629 	mtx_init(&gmtbq_mtx, "gmtbq", NULL, MTX_DEF);
630 	kproc_create(g_multipath_kt, mp, NULL, 0, 0, "g_mp_kt");
631 }
632 
633 static void
634 g_multipath_fini(struct g_class *mp)
635 {
636 	if (g_multipath_kt_state == GKT_RUN) {
637 		mtx_lock(&gmtbq_mtx);
638 		g_multipath_kt_state = GKT_DIE;
639 		wakeup(&g_multipath_kt_state);
640 		msleep(&g_multipath_kt_state, &gmtbq_mtx, PRIBIO,
641 		    "gmp:fini", 0);
642 		mtx_unlock(&gmtbq_mtx);
643 	}
644 }
645 
646 static int
647 g_multipath_read_metadata(struct g_consumer *cp,
648     struct g_multipath_metadata *md)
649 {
650 	struct g_provider *pp;
651 	u_char *buf;
652 	int error;
653 
654 	g_topology_assert();
655 	error = g_access(cp, 1, 0, 0);
656 	if (error != 0)
657 		return (error);
658 	pp = cp->provider;
659 	g_topology_unlock();
660 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize,
661 	    pp->sectorsize, &error);
662 	g_topology_lock();
663 	g_access(cp, -1, 0, 0);
664 	if (buf == NULL)
665 		return (error);
666 	multipath_metadata_decode(buf, md);
667 	g_free(buf);
668 	return (0);
669 }
670 
671 static struct g_geom *
672 g_multipath_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
673 {
674 	struct g_multipath_metadata md;
675 	struct g_multipath_softc *sc;
676 	struct g_consumer *cp;
677 	struct g_geom *gp, *gp1;
678 	int error, isnew;
679 
680 	g_topology_assert();
681 
682 	gp = g_new_geomf(mp, "multipath:taste");
683 	gp->start = g_multipath_start;
684 	gp->access = g_multipath_access;
685 	gp->orphan = g_multipath_orphan;
686 	cp = g_new_consumer(gp);
687 	g_attach(cp, pp);
688 	error = g_multipath_read_metadata(cp, &md);
689 	g_detach(cp);
690 	g_destroy_consumer(cp);
691 	g_destroy_geom(gp);
692 	if (error != 0)
693 		return (NULL);
694 	gp = NULL;
695 
696 	if (strcmp(md.md_magic, G_MULTIPATH_MAGIC) != 0) {
697 		if (g_multipath_debug)
698 			printf("%s is not MULTIPATH\n", pp->name);
699 		return (NULL);
700 	}
701 	if (md.md_version != G_MULTIPATH_VERSION) {
702 		printf("%s has version %d multipath id- this module is version "
703 		    " %d: rejecting\n", pp->name, md.md_version,
704 		    G_MULTIPATH_VERSION);
705 		return (NULL);
706 	}
707 	if (md.md_size != 0 && md.md_size != pp->mediasize)
708 		return (NULL);
709 	if (md.md_sectorsize != 0 && md.md_sectorsize != pp->sectorsize)
710 		return (NULL);
711 	if (g_multipath_debug)
712 		printf("MULTIPATH: %s/%s\n", md.md_name, md.md_uuid);
713 
714 	/*
715 	 * Let's check if such a device already is present. We check against
716 	 * uuid alone first because that's the true distinguishor. If that
717 	 * passes, then we check for name conflicts. If there are conflicts,
718 	 * modify the name.
719 	 *
720 	 * The whole purpose of this is to solve the problem that people don't
721 	 * pick good unique names, but good unique names (like uuids) are a
722 	 * pain to use. So, we allow people to build GEOMs with friendly names
723 	 * and uuids, and modify the names in case there's a collision.
724 	 */
725 	sc = NULL;
726 	LIST_FOREACH(gp, &mp->geom, geom) {
727 		sc = gp->softc;
728 		if (sc == NULL || sc->sc_stopping)
729 			continue;
730 		if (strncmp(md.md_uuid, sc->sc_uuid, sizeof(md.md_uuid)) == 0)
731 			break;
732 	}
733 
734 	LIST_FOREACH(gp1, &mp->geom, geom) {
735 		if (gp1 == gp)
736 			continue;
737 		sc = gp1->softc;
738 		if (sc == NULL || sc->sc_stopping)
739 			continue;
740 		if (strncmp(md.md_name, sc->sc_name, sizeof(md.md_name)) == 0)
741 			break;
742 	}
743 
744 	/*
745 	 * If gp is NULL, we had no extant MULTIPATH geom with this uuid.
746 	 *
747 	 * If gp1 is *not* NULL, that means we have a MULTIPATH geom extant
748 	 * with the same name (but a different UUID).
749 	 *
750 	 * If gp is NULL, then modify the name with a random number and
751   	 * complain, but allow the creation of the geom to continue.
752 	 *
753 	 * If gp is *not* NULL, just use the geom's name as we're attaching
754 	 * this disk to the (previously generated) name.
755 	 */
756 
757 	if (gp1) {
758 		sc = gp1->softc;
759 		if (gp == NULL) {
760 			char buf[16];
761 			u_long rand = random();
762 
763 			snprintf(buf, sizeof (buf), "%s-%lu", md.md_name, rand);
764 			printf("GEOM_MULTIPATH: geom %s/%s exists already\n",
765 			    sc->sc_name, sc->sc_uuid);
766 			printf("GEOM_MULTIPATH: %s will be (temporarily) %s\n",
767 			    md.md_uuid, buf);
768 			strlcpy(md.md_name, buf, sizeof(md.md_name));
769 		} else {
770 			strlcpy(md.md_name, sc->sc_name, sizeof(md.md_name));
771 		}
772 	}
773 
774 	if (gp == NULL) {
775 		gp = g_multipath_create(mp, &md);
776 		if (gp == NULL) {
777 			printf("GEOM_MULTIPATH: cannot create geom %s/%s\n",
778 			    md.md_name, md.md_uuid);
779 			return (NULL);
780 		}
781 		isnew = 1;
782 	} else {
783 		isnew = 0;
784 	}
785 
786 	sc = gp->softc;
787 	KASSERT(sc != NULL, ("sc is NULL"));
788 	error = g_multipath_add_disk(gp, pp);
789 	if (error != 0) {
790 		if (isnew)
791 			g_multipath_destroy(gp);
792 		return (NULL);
793 	}
794 	return (gp);
795 }
796 
797 static void
798 g_multipath_ctl_add_name(struct gctl_req *req, struct g_class *mp,
799     const char *name)
800 {
801 	struct g_multipath_softc *sc;
802 	struct g_geom *gp;
803 	struct g_consumer *cp;
804 	struct g_provider *pp;
805 	const char *mpname;
806 	static const char devpf[6] = "/dev/";
807 
808 	g_topology_assert();
809 
810 	mpname = gctl_get_asciiparam(req, "arg0");
811         if (mpname == NULL) {
812                 gctl_error(req, "No 'arg0' argument");
813                 return;
814         }
815 	gp = g_multipath_find_geom(mp, mpname);
816 	if (gp == NULL) {
817 		gctl_error(req, "Device %s is invalid", mpname);
818 		return;
819 	}
820 	sc = gp->softc;
821 
822 	if (strncmp(name, devpf, 5) == 0)
823 		name += 5;
824 	pp = g_provider_by_name(name);
825 	if (pp == NULL) {
826 		gctl_error(req, "Provider %s is invalid", name);
827 		return;
828 	}
829 
830 	/*
831 	 * Check to make sure parameters match.
832 	 */
833 	LIST_FOREACH(cp, &gp->consumer, consumer) {
834 		if (cp->provider == pp) {
835 			gctl_error(req, "provider %s is already there",
836 			    pp->name);
837 			return;
838 		}
839 	}
840 	if (sc->sc_pp != NULL && sc->sc_pp->mediasize != 0 &&
841 	    sc->sc_pp->mediasize + (sc->sc_uuid[0] != 0 ? pp->sectorsize : 0)
842 	     != pp->mediasize) {
843 		gctl_error(req, "Providers size mismatch %jd != %jd",
844 		    (intmax_t) sc->sc_pp->mediasize +
845 			(sc->sc_uuid[0] != 0 ? pp->sectorsize : 0),
846 		    (intmax_t) pp->mediasize);
847 		return;
848 	}
849 	if (sc->sc_pp != NULL && sc->sc_pp->sectorsize != 0 &&
850 	    sc->sc_pp->sectorsize != pp->sectorsize) {
851 		gctl_error(req, "Providers sectorsize mismatch %u != %u",
852 		    sc->sc_pp->sectorsize, pp->sectorsize);
853 		return;
854 	}
855 
856 	/*
857 	 * Now add....
858 	 */
859 	(void) g_multipath_add_disk(gp, pp);
860 }
861 
862 static void
863 g_multipath_ctl_prefer(struct gctl_req *req, struct g_class *mp)
864 {
865 	struct g_geom *gp;
866 	struct g_multipath_softc *sc;
867 	struct g_consumer *cp;
868 	const char *name, *mpname;
869 	static const char devpf[6] = "/dev/";
870 	int *nargs;
871 
872 	g_topology_assert();
873 
874 	mpname = gctl_get_asciiparam(req, "arg0");
875         if (mpname == NULL) {
876                 gctl_error(req, "No 'arg0' argument");
877                 return;
878         }
879 	gp = g_multipath_find_geom(mp, mpname);
880 	if (gp == NULL) {
881 		gctl_error(req, "Device %s is invalid", mpname);
882 		return;
883 	}
884 	sc = gp->softc;
885 
886 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
887 	if (nargs == NULL) {
888 		gctl_error(req, "No 'nargs' argument");
889 		return;
890 	}
891 	if (*nargs != 2) {
892 		gctl_error(req, "missing device");
893 		return;
894 	}
895 
896 	name = gctl_get_asciiparam(req, "arg1");
897 	if (name == NULL) {
898 		gctl_error(req, "No 'arg1' argument");
899 		return;
900 	}
901 	if (strncmp(name, devpf, 5) == 0) {
902 		name += 5;
903 	}
904 
905 	LIST_FOREACH(cp, &gp->consumer, consumer) {
906 		if (cp->provider != NULL
907                       && strcmp(cp->provider->name, name) == 0)
908 		    break;
909 	}
910 
911 	if (cp == NULL) {
912 		gctl_error(req, "Provider %s not found", name);
913 		return;
914 	}
915 
916 	mtx_lock(&sc->sc_mtx);
917 
918 	if (cp->index & MP_BAD) {
919 		gctl_error(req, "Consumer %s is invalid", name);
920 		mtx_unlock(&sc->sc_mtx);
921 		return;
922 	}
923 
924 	/* Here when the consumer is present and in good shape */
925 
926 	sc->sc_active = cp;
927 	if (!sc->sc_active_active)
928 	    printf("GEOM_MULTIPATH: %s now active path in %s\n",
929 		sc->sc_active->provider->name, sc->sc_name);
930 
931 	mtx_unlock(&sc->sc_mtx);
932 }
933 
934 static void
935 g_multipath_ctl_add(struct gctl_req *req, struct g_class *mp)
936 {
937 	struct g_multipath_softc *sc;
938 	struct g_geom *gp;
939 	const char *mpname, *name;
940 
941 	mpname = gctl_get_asciiparam(req, "arg0");
942         if (mpname == NULL) {
943                 gctl_error(req, "No 'arg0' argument");
944                 return;
945         }
946 	gp = g_multipath_find_geom(mp, mpname);
947 	if (gp == NULL) {
948 		gctl_error(req, "Device %s not found", mpname);
949 		return;
950 	}
951 	sc = gp->softc;
952 
953 	name = gctl_get_asciiparam(req, "arg1");
954 	if (name == NULL) {
955 		gctl_error(req, "No 'arg1' argument");
956 		return;
957 	}
958 	g_multipath_ctl_add_name(req, mp, name);
959 }
960 
961 static void
962 g_multipath_ctl_create(struct gctl_req *req, struct g_class *mp)
963 {
964 	struct g_multipath_metadata md;
965 	struct g_multipath_softc *sc;
966 	struct g_geom *gp;
967 	const char *mpname, *name;
968 	char param[16];
969 	int *nargs, i, *val;
970 
971 	g_topology_assert();
972 
973 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
974 	if (*nargs < 2) {
975 		gctl_error(req, "wrong number of arguments.");
976 		return;
977 	}
978 
979 	mpname = gctl_get_asciiparam(req, "arg0");
980         if (mpname == NULL) {
981                 gctl_error(req, "No 'arg0' argument");
982                 return;
983         }
984 	gp = g_multipath_find_geom(mp, mpname);
985 	if (gp != NULL) {
986 		gctl_error(req, "Device %s already exist", mpname);
987 		return;
988 	}
989 	sc = gp->softc;
990 
991 	memset(&md, 0, sizeof(md));
992 	strlcpy(md.md_magic, G_MULTIPATH_MAGIC, sizeof(md.md_magic));
993 	md.md_version = G_MULTIPATH_VERSION;
994 	strlcpy(md.md_name, mpname, sizeof(md.md_name));
995 	md.md_size = 0;
996 	md.md_sectorsize = 0;
997 	md.md_uuid[0] = 0;
998 	md.md_active_active = 0;
999 	val = gctl_get_paraml(req, "active_active", sizeof(*val));
1000 	if (val != NULL && *val != 0)
1001 		md.md_active_active = 1;
1002 	val = gctl_get_paraml(req, "active_read", sizeof(*val));
1003 	if (val != NULL && *val != 0)
1004 		md.md_active_active = 2;
1005 	gp = g_multipath_create(mp, &md);
1006 	if (gp == NULL) {
1007 		gctl_error(req, "GEOM_MULTIPATH: cannot create geom %s/%s\n",
1008 		    md.md_name, md.md_uuid);
1009 		return;
1010 	}
1011 	sc = gp->softc;
1012 
1013 	for (i = 1; i < *nargs; i++) {
1014 		snprintf(param, sizeof(param), "arg%d", i);
1015 		name = gctl_get_asciiparam(req, param);
1016 		g_multipath_ctl_add_name(req, mp, name);
1017 	}
1018 
1019 	if (sc->sc_ndisks != (*nargs - 1))
1020 		g_multipath_destroy(gp);
1021 }
1022 
1023 static void
1024 g_multipath_ctl_configure(struct gctl_req *req, struct g_class *mp)
1025 {
1026 	struct g_multipath_softc *sc;
1027 	struct g_geom *gp;
1028 	struct g_consumer *cp;
1029 	struct g_provider *pp;
1030 	struct g_multipath_metadata md;
1031 	const char *name;
1032 	int error, *val;
1033 	void *buf;
1034 
1035 	g_topology_assert();
1036 
1037 	name = gctl_get_asciiparam(req, "arg0");
1038 	if (name == NULL) {
1039 		gctl_error(req, "No 'arg0' argument");
1040 		return;
1041 	}
1042 	gp = g_multipath_find_geom(mp, name);
1043 	if (gp == NULL) {
1044 		gctl_error(req, "Device %s is invalid", name);
1045 		return;
1046 	}
1047 	sc = gp->softc;
1048 	val = gctl_get_paraml(req, "active_active", sizeof(*val));
1049 	if (val != NULL && *val != 0)
1050 		sc->sc_active_active = 1;
1051 	val = gctl_get_paraml(req, "active_read", sizeof(*val));
1052 	if (val != NULL && *val != 0)
1053 		sc->sc_active_active = 2;
1054 	val = gctl_get_paraml(req, "active_passive", sizeof(*val));
1055 	if (val != NULL && *val != 0)
1056 		sc->sc_active_active = 0;
1057 	if (sc->sc_uuid[0] != 0 && sc->sc_active != NULL) {
1058 		cp = sc->sc_active;
1059 		pp = cp->provider;
1060 		error = g_access(cp, 1, 1, 1);
1061 		if (error != 0) {
1062 			gctl_error(req, "Can't open %s (%d)", pp->name, error);
1063 			return;
1064 		}
1065 		g_topology_unlock();
1066 		buf = g_malloc(pp->sectorsize, M_WAITOK | M_ZERO);
1067 		strlcpy(md.md_magic, G_MULTIPATH_MAGIC, sizeof(md.md_magic));
1068 		memcpy(md.md_uuid, sc->sc_uuid, sizeof (sc->sc_uuid));
1069 		strlcpy(md.md_name, name, sizeof(md.md_name));
1070 		md.md_version = G_MULTIPATH_VERSION;
1071 		md.md_size = pp->mediasize;
1072 		md.md_sectorsize = pp->sectorsize;
1073 		md.md_active_active = sc->sc_active_active;
1074 		multipath_metadata_encode(&md, buf);
1075 		error = g_write_data(cp, pp->mediasize - pp->sectorsize,
1076 		    buf, pp->sectorsize);
1077 		g_topology_lock();
1078 		g_access(cp, -1, -1, -1);
1079 		if (error != 0)
1080 			gctl_error(req, "Can't update metadata on %s (%d)",
1081 			    pp->name, error);
1082 	}
1083 }
1084 
1085 static void
1086 g_multipath_ctl_fail(struct gctl_req *req, struct g_class *mp, int fail)
1087 {
1088 	struct g_multipath_softc *sc;
1089 	struct g_geom *gp;
1090 	struct g_consumer *cp;
1091 	const char *mpname, *name;
1092 	int found;
1093 
1094 	mpname = gctl_get_asciiparam(req, "arg0");
1095         if (mpname == NULL) {
1096                 gctl_error(req, "No 'arg0' argument");
1097                 return;
1098         }
1099 	gp = g_multipath_find_geom(mp, mpname);
1100 	if (gp == NULL) {
1101 		gctl_error(req, "Device %s not found", mpname);
1102 		return;
1103 	}
1104 	sc = gp->softc;
1105 
1106 	name = gctl_get_asciiparam(req, "arg1");
1107 	if (name == NULL) {
1108 		gctl_error(req, "No 'arg1' argument");
1109 		return;
1110 	}
1111 
1112 	found = 0;
1113 	mtx_lock(&sc->sc_mtx);
1114 	LIST_FOREACH(cp, &gp->consumer, consumer) {
1115 		if (cp->provider != NULL &&
1116 		    strcmp(cp->provider->name, name) == 0 &&
1117 		    (cp->index & MP_LOST) == 0) {
1118 			found = 1;
1119 			if (!fail == !(cp->index & MP_FAIL))
1120 				continue;
1121 			printf("GEOM_MULTIPATH: %s in %s is marked %s.\n",
1122 				name, sc->sc_name, fail ? "FAIL" : "OK");
1123 			if (fail) {
1124 				g_multipath_fault(cp, MP_FAIL);
1125 			} else {
1126 				cp->index &= ~MP_FAIL;
1127 			}
1128 		}
1129 	}
1130 	mtx_unlock(&sc->sc_mtx);
1131 	if (found == 0)
1132 		gctl_error(req, "Provider %s not found", name);
1133 }
1134 
1135 static void
1136 g_multipath_ctl_remove(struct gctl_req *req, struct g_class *mp)
1137 {
1138 	struct g_multipath_softc *sc;
1139 	struct g_geom *gp;
1140 	struct g_consumer *cp, *cp1;
1141 	const char *mpname, *name;
1142 	uintptr_t *cnt;
1143 	int found;
1144 
1145 	mpname = gctl_get_asciiparam(req, "arg0");
1146         if (mpname == NULL) {
1147                 gctl_error(req, "No 'arg0' argument");
1148                 return;
1149         }
1150 	gp = g_multipath_find_geom(mp, mpname);
1151 	if (gp == NULL) {
1152 		gctl_error(req, "Device %s not found", mpname);
1153 		return;
1154 	}
1155 	sc = gp->softc;
1156 
1157 	name = gctl_get_asciiparam(req, "arg1");
1158 	if (name == NULL) {
1159 		gctl_error(req, "No 'arg1' argument");
1160 		return;
1161 	}
1162 
1163 	found = 0;
1164 	mtx_lock(&sc->sc_mtx);
1165 	LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp1) {
1166 		if (cp->provider != NULL &&
1167 		    strcmp(cp->provider->name, name) == 0 &&
1168 		    (cp->index & MP_LOST) == 0) {
1169 			found = 1;
1170 			printf("GEOM_MULTIPATH: removing %s from %s\n",
1171 			    cp->provider->name, cp->geom->name);
1172 			sc->sc_ndisks--;
1173 			g_multipath_fault(cp, MP_LOST);
1174 			cnt = (uintptr_t *)&cp->private;
1175 			if (*cnt == 0 && (cp->index & MP_POSTED) == 0) {
1176 				cp->index |= MP_POSTED;
1177 				mtx_unlock(&sc->sc_mtx);
1178 				g_mpd(cp, 0);
1179 				if (cp1 == NULL)
1180 					return;	/* Recursion happened. */
1181 				mtx_lock(&sc->sc_mtx);
1182 			}
1183 		}
1184 	}
1185 	mtx_unlock(&sc->sc_mtx);
1186 	if (found == 0)
1187 		gctl_error(req, "Provider %s not found", name);
1188 }
1189 
1190 static struct g_geom *
1191 g_multipath_find_geom(struct g_class *mp, const char *name)
1192 {
1193 	struct g_geom *gp;
1194 	struct g_multipath_softc *sc;
1195 
1196 	LIST_FOREACH(gp, &mp->geom, geom) {
1197 		sc = gp->softc;
1198 		if (sc == NULL || sc->sc_stopping)
1199 			continue;
1200 		if (strcmp(gp->name, name) == 0)
1201 			return (gp);
1202 	}
1203 	return (NULL);
1204 }
1205 
1206 static void
1207 g_multipath_ctl_stop(struct gctl_req *req, struct g_class *mp)
1208 {
1209 	struct g_geom *gp;
1210 	const char *name;
1211 	int error;
1212 
1213 	g_topology_assert();
1214 
1215 	name = gctl_get_asciiparam(req, "arg0");
1216         if (name == NULL) {
1217                 gctl_error(req, "No 'arg0' argument");
1218                 return;
1219         }
1220 	gp = g_multipath_find_geom(mp, name);
1221 	if (gp == NULL) {
1222 		gctl_error(req, "Device %s is invalid", name);
1223 		return;
1224 	}
1225 	error = g_multipath_destroy(gp);
1226 	if (error != 0 && error != EINPROGRESS)
1227 		gctl_error(req, "failed to stop %s (err=%d)", name, error);
1228 }
1229 
1230 static void
1231 g_multipath_ctl_destroy(struct gctl_req *req, struct g_class *mp)
1232 {
1233 	struct g_geom *gp;
1234 	struct g_multipath_softc *sc;
1235 	struct g_consumer *cp;
1236 	struct g_provider *pp;
1237 	const char *name;
1238 	uint8_t *buf;
1239 	int error;
1240 
1241 	g_topology_assert();
1242 
1243 	name = gctl_get_asciiparam(req, "arg0");
1244         if (name == NULL) {
1245                 gctl_error(req, "No 'arg0' argument");
1246                 return;
1247         }
1248 	gp = g_multipath_find_geom(mp, name);
1249 	if (gp == NULL) {
1250 		gctl_error(req, "Device %s is invalid", name);
1251 		return;
1252 	}
1253 	sc = gp->softc;
1254 
1255 	if (sc->sc_uuid[0] != 0 && sc->sc_active != NULL) {
1256 		cp = sc->sc_active;
1257 		pp = cp->provider;
1258 		error = g_access(cp, 1, 1, 1);
1259 		if (error != 0) {
1260 			gctl_error(req, "Can't open %s (%d)", pp->name, error);
1261 			goto destroy;
1262 		}
1263 		g_topology_unlock();
1264 		buf = g_malloc(pp->sectorsize, M_WAITOK | M_ZERO);
1265 		error = g_write_data(cp, pp->mediasize - pp->sectorsize,
1266 		    buf, pp->sectorsize);
1267 		g_topology_lock();
1268 		g_access(cp, -1, -1, -1);
1269 		if (error != 0)
1270 			gctl_error(req, "Can't erase metadata on %s (%d)",
1271 			    pp->name, error);
1272 	}
1273 
1274 destroy:
1275 	error = g_multipath_destroy(gp);
1276 	if (error != 0 && error != EINPROGRESS)
1277 		gctl_error(req, "failed to destroy %s (err=%d)", name, error);
1278 }
1279 
1280 static void
1281 g_multipath_ctl_rotate(struct gctl_req *req, struct g_class *mp)
1282 {
1283 	struct g_geom *gp;
1284 	const char *name;
1285 	int error;
1286 
1287 	g_topology_assert();
1288 
1289 	name = gctl_get_asciiparam(req, "arg0");
1290         if (name == NULL) {
1291                 gctl_error(req, "No 'arg0' argument");
1292                 return;
1293         }
1294 	gp = g_multipath_find_geom(mp, name);
1295 	if (gp == NULL) {
1296 		gctl_error(req, "Device %s is invalid", name);
1297 		return;
1298 	}
1299 	error = g_multipath_rotate(gp);
1300 	if (error != 0) {
1301 		gctl_error(req, "failed to rotate %s (err=%d)", name, error);
1302 	}
1303 }
1304 
1305 static void
1306 g_multipath_ctl_getactive(struct gctl_req *req, struct g_class *mp)
1307 {
1308 	struct sbuf *sb;
1309 	struct g_geom *gp;
1310 	struct g_multipath_softc *sc;
1311 	struct g_consumer *cp;
1312 	const char *name;
1313 	int empty;
1314 
1315 	sb = sbuf_new_auto();
1316 
1317 	g_topology_assert();
1318 	name = gctl_get_asciiparam(req, "arg0");
1319         if (name == NULL) {
1320                 gctl_error(req, "No 'arg0' argument");
1321                 return;
1322         }
1323 	gp = g_multipath_find_geom(mp, name);
1324 	if (gp == NULL) {
1325 		gctl_error(req, "Device %s is invalid", name);
1326 		return;
1327 	}
1328 	sc = gp->softc;
1329 	if (sc->sc_active_active == 1) {
1330 		empty = 1;
1331 		LIST_FOREACH(cp, &gp->consumer, consumer) {
1332 			if (cp->index & MP_BAD)
1333 				continue;
1334 			if (!empty)
1335 				sbuf_cat(sb, " ");
1336 			sbuf_cat(sb, cp->provider->name);
1337 			empty = 0;
1338 		}
1339 		if (empty)
1340 			sbuf_cat(sb, "none");
1341 		sbuf_cat(sb, "\n");
1342 	} else if (sc->sc_active && sc->sc_active->provider) {
1343 		sbuf_printf(sb, "%s\n", sc->sc_active->provider->name);
1344 	} else {
1345 		sbuf_printf(sb, "none\n");
1346 	}
1347 	sbuf_finish(sb);
1348 	gctl_set_param_err(req, "output", sbuf_data(sb), sbuf_len(sb) + 1);
1349 	sbuf_delete(sb);
1350 }
1351 
1352 static void
1353 g_multipath_config(struct gctl_req *req, struct g_class *mp, const char *verb)
1354 {
1355 	uint32_t *version;
1356 	g_topology_assert();
1357 	version = gctl_get_paraml(req, "version", sizeof(*version));
1358 	if (version == NULL) {
1359 		gctl_error(req, "No 'version' argument");
1360 	} else if (*version != G_MULTIPATH_VERSION) {
1361 		gctl_error(req, "Userland and kernel parts are out of sync");
1362 	} else if (strcmp(verb, "add") == 0) {
1363 		g_multipath_ctl_add(req, mp);
1364 	} else if (strcmp(verb, "prefer") == 0) {
1365 		g_multipath_ctl_prefer(req, mp);
1366 	} else if (strcmp(verb, "create") == 0) {
1367 		g_multipath_ctl_create(req, mp);
1368 	} else if (strcmp(verb, "configure") == 0) {
1369 		g_multipath_ctl_configure(req, mp);
1370 	} else if (strcmp(verb, "stop") == 0) {
1371 		g_multipath_ctl_stop(req, mp);
1372 	} else if (strcmp(verb, "destroy") == 0) {
1373 		g_multipath_ctl_destroy(req, mp);
1374 	} else if (strcmp(verb, "fail") == 0) {
1375 		g_multipath_ctl_fail(req, mp, 1);
1376 	} else if (strcmp(verb, "restore") == 0) {
1377 		g_multipath_ctl_fail(req, mp, 0);
1378 	} else if (strcmp(verb, "remove") == 0) {
1379 		g_multipath_ctl_remove(req, mp);
1380 	} else if (strcmp(verb, "rotate") == 0) {
1381 		g_multipath_ctl_rotate(req, mp);
1382 	} else if (strcmp(verb, "getactive") == 0) {
1383 		g_multipath_ctl_getactive(req, mp);
1384 	} else {
1385 		gctl_error(req, "Unknown verb %s", verb);
1386 	}
1387 }
1388 
1389 static void
1390 g_multipath_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
1391     struct g_consumer *cp, struct g_provider *pp)
1392 {
1393 	struct g_multipath_softc *sc;
1394 	int good;
1395 
1396 	g_topology_assert();
1397 
1398 	sc = gp->softc;
1399 	if (sc == NULL)
1400 		return;
1401 	if (cp != NULL) {
1402 		sbuf_printf(sb, "%s<State>%s</State>\n", indent,
1403 		    (cp->index & MP_NEW) ? "NEW" :
1404 		    (cp->index & MP_LOST) ? "LOST" :
1405 		    (cp->index & MP_FAIL) ? "FAIL" :
1406 		    (sc->sc_active_active == 1 || sc->sc_active == cp) ?
1407 		     "ACTIVE" :
1408 		     sc->sc_active_active == 2 ? "READ" : "PASSIVE");
1409 	} else {
1410 		good = g_multipath_good(gp);
1411 		sbuf_printf(sb, "%s<State>%s</State>\n", indent,
1412 		    good == 0 ? "BROKEN" :
1413 		    (good != sc->sc_ndisks || sc->sc_ndisks == 1) ?
1414 		    "DEGRADED" : "OPTIMAL");
1415 	}
1416 	if (cp == NULL && pp == NULL) {
1417 		sbuf_printf(sb, "%s<UUID>%s</UUID>\n", indent, sc->sc_uuid);
1418 		sbuf_printf(sb, "%s<Mode>Active/%s</Mode>\n", indent,
1419 		    sc->sc_active_active == 2 ? "Read" :
1420 		    sc->sc_active_active == 1 ? "Active" : "Passive");
1421 		sbuf_printf(sb, "%s<Type>%s</Type>\n", indent,
1422 		    sc->sc_uuid[0] == 0 ? "MANUAL" : "AUTOMATIC");
1423 	}
1424 }
1425 
1426 DECLARE_GEOM_CLASS(g_multipath_class, g_multipath);
1427