xref: /freebsd/sys/geom/concat/g_concat.c (revision f05cddf9)
1 /*-
2  * Copyright (c) 2004-2005 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/kernel.h>
33 #include <sys/module.h>
34 #include <sys/lock.h>
35 #include <sys/mutex.h>
36 #include <sys/bio.h>
37 #include <sys/sbuf.h>
38 #include <sys/sysctl.h>
39 #include <sys/malloc.h>
40 #include <geom/geom.h>
41 #include <geom/concat/g_concat.h>
42 
43 FEATURE(geom_concat, "GEOM concatenation support");
44 
45 static MALLOC_DEFINE(M_CONCAT, "concat_data", "GEOM_CONCAT Data");
46 
47 SYSCTL_DECL(_kern_geom);
48 static SYSCTL_NODE(_kern_geom, OID_AUTO, concat, CTLFLAG_RW, 0,
49     "GEOM_CONCAT stuff");
50 static u_int g_concat_debug = 0;
51 TUNABLE_INT("kern.geom.concat.debug", &g_concat_debug);
52 SYSCTL_UINT(_kern_geom_concat, OID_AUTO, debug, CTLFLAG_RW, &g_concat_debug, 0,
53     "Debug level");
54 
55 static int g_concat_destroy(struct g_concat_softc *sc, boolean_t force);
56 static int g_concat_destroy_geom(struct gctl_req *req, struct g_class *mp,
57     struct g_geom *gp);
58 
59 static g_taste_t g_concat_taste;
60 static g_ctl_req_t g_concat_config;
61 static g_dumpconf_t g_concat_dumpconf;
62 
63 struct g_class g_concat_class = {
64 	.name = G_CONCAT_CLASS_NAME,
65 	.version = G_VERSION,
66 	.ctlreq = g_concat_config,
67 	.taste = g_concat_taste,
68 	.destroy_geom = g_concat_destroy_geom
69 };
70 
71 
72 /*
73  * Greatest Common Divisor.
74  */
75 static u_int
76 gcd(u_int a, u_int b)
77 {
78 	u_int c;
79 
80 	while (b != 0) {
81 		c = a;
82 		a = b;
83 		b = (c % b);
84 	}
85 	return (a);
86 }
87 
88 /*
89  * Least Common Multiple.
90  */
91 static u_int
92 lcm(u_int a, u_int b)
93 {
94 
95 	return ((a * b) / gcd(a, b));
96 }
97 
98 /*
99  * Return the number of valid disks.
100  */
101 static u_int
102 g_concat_nvalid(struct g_concat_softc *sc)
103 {
104 	u_int i, no;
105 
106 	no = 0;
107 	for (i = 0; i < sc->sc_ndisks; i++) {
108 		if (sc->sc_disks[i].d_consumer != NULL)
109 			no++;
110 	}
111 
112 	return (no);
113 }
114 
115 static void
116 g_concat_remove_disk(struct g_concat_disk *disk)
117 {
118 	struct g_consumer *cp;
119 	struct g_concat_softc *sc;
120 
121 	g_topology_assert();
122 	KASSERT(disk->d_consumer != NULL, ("Non-valid disk in %s.", __func__));
123 	sc = disk->d_softc;
124 	cp = disk->d_consumer;
125 
126 	if (!disk->d_removed) {
127 		G_CONCAT_DEBUG(0, "Disk %s removed from %s.",
128 		    cp->provider->name, sc->sc_name);
129 		disk->d_removed = 1;
130 	}
131 
132 	if (sc->sc_provider != NULL) {
133 		sc->sc_provider->flags |= G_PF_WITHER;
134 		G_CONCAT_DEBUG(0, "Device %s deactivated.",
135 		    sc->sc_provider->name);
136 		g_orphan_provider(sc->sc_provider, ENXIO);
137 		sc->sc_provider = NULL;
138 	}
139 
140 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
141 		return;
142 	disk->d_consumer = NULL;
143 	g_detach(cp);
144 	g_destroy_consumer(cp);
145 	/* If there are no valid disks anymore, remove device. */
146 	if (LIST_EMPTY(&sc->sc_geom->consumer))
147 		g_concat_destroy(sc, 1);
148 }
149 
150 static void
151 g_concat_orphan(struct g_consumer *cp)
152 {
153 	struct g_concat_softc *sc;
154 	struct g_concat_disk *disk;
155 	struct g_geom *gp;
156 
157 	g_topology_assert();
158 	gp = cp->geom;
159 	sc = gp->softc;
160 	if (sc == NULL)
161 		return;
162 
163 	disk = cp->private;
164 	if (disk == NULL)	/* Possible? */
165 		return;
166 	g_concat_remove_disk(disk);
167 }
168 
169 static int
170 g_concat_access(struct g_provider *pp, int dr, int dw, int de)
171 {
172 	struct g_consumer *cp1, *cp2, *tmp;
173 	struct g_concat_disk *disk;
174 	struct g_geom *gp;
175 	int error;
176 
177 	g_topology_assert();
178 	gp = pp->geom;
179 
180 	/* On first open, grab an extra "exclusive" bit */
181 	if (pp->acr == 0 && pp->acw == 0 && pp->ace == 0)
182 		de++;
183 	/* ... and let go of it on last close */
184 	if ((pp->acr + dr) == 0 && (pp->acw + dw) == 0 && (pp->ace + de) == 0)
185 		de--;
186 
187 	LIST_FOREACH_SAFE(cp1, &gp->consumer, consumer, tmp) {
188 		error = g_access(cp1, dr, dw, de);
189 		if (error != 0)
190 			goto fail;
191 		disk = cp1->private;
192 		if (cp1->acr == 0 && cp1->acw == 0 && cp1->ace == 0 &&
193 		    disk->d_removed) {
194 			g_concat_remove_disk(disk); /* May destroy geom. */
195 		}
196 	}
197 	return (0);
198 
199 fail:
200 	LIST_FOREACH(cp2, &gp->consumer, consumer) {
201 		if (cp1 == cp2)
202 			break;
203 		g_access(cp2, -dr, -dw, -de);
204 	}
205 	return (error);
206 }
207 
208 static void
209 g_concat_kernel_dump(struct bio *bp)
210 {
211 	struct g_concat_softc *sc;
212 	struct g_concat_disk *disk;
213 	struct bio *cbp;
214 	struct g_kerneldump *gkd;
215 	u_int i;
216 
217 	sc = bp->bio_to->geom->softc;
218 	gkd = (struct g_kerneldump *)bp->bio_data;
219 	for (i = 0; i < sc->sc_ndisks; i++) {
220 		if (sc->sc_disks[i].d_start <= gkd->offset &&
221 		    sc->sc_disks[i].d_end > gkd->offset)
222 			break;
223 	}
224 	if (i == sc->sc_ndisks)
225 		g_io_deliver(bp, EOPNOTSUPP);
226 	disk = &sc->sc_disks[i];
227 	gkd->offset -= disk->d_start;
228 	if (gkd->length > disk->d_end - disk->d_start - gkd->offset)
229 		gkd->length = disk->d_end - disk->d_start - gkd->offset;
230 	cbp = g_clone_bio(bp);
231 	if (cbp == NULL) {
232 		g_io_deliver(bp, ENOMEM);
233 		return;
234 	}
235 	cbp->bio_done = g_std_done;
236 	g_io_request(cbp, disk->d_consumer);
237 	G_CONCAT_DEBUG(1, "Kernel dump will go to %s.",
238 	    disk->d_consumer->provider->name);
239 }
240 
241 static void
242 g_concat_flush(struct g_concat_softc *sc, struct bio *bp)
243 {
244 	struct bio_queue_head queue;
245 	struct g_consumer *cp;
246 	struct bio *cbp;
247 	u_int no;
248 
249 	bioq_init(&queue);
250 	for (no = 0; no < sc->sc_ndisks; no++) {
251 		cbp = g_clone_bio(bp);
252 		if (cbp == NULL) {
253 			for (cbp = bioq_first(&queue); cbp != NULL;
254 			    cbp = bioq_first(&queue)) {
255 				bioq_remove(&queue, cbp);
256 				g_destroy_bio(cbp);
257 			}
258 			if (bp->bio_error == 0)
259 				bp->bio_error = ENOMEM;
260 			g_io_deliver(bp, bp->bio_error);
261 			return;
262 		}
263 		bioq_insert_tail(&queue, cbp);
264 		cbp->bio_done = g_std_done;
265 		cbp->bio_caller1 = sc->sc_disks[no].d_consumer;
266 		cbp->bio_to = sc->sc_disks[no].d_consumer->provider;
267 	}
268 	for (cbp = bioq_first(&queue); cbp != NULL; cbp = bioq_first(&queue)) {
269 		bioq_remove(&queue, cbp);
270 		G_CONCAT_LOGREQ(cbp, "Sending request.");
271 		cp = cbp->bio_caller1;
272 		cbp->bio_caller1 = NULL;
273 		g_io_request(cbp, cp);
274 	}
275 }
276 
277 static void
278 g_concat_start(struct bio *bp)
279 {
280 	struct bio_queue_head queue;
281 	struct g_concat_softc *sc;
282 	struct g_concat_disk *disk;
283 	struct g_provider *pp;
284 	off_t offset, end, length, off, len;
285 	struct bio *cbp;
286 	char *addr;
287 	u_int no;
288 
289 	pp = bp->bio_to;
290 	sc = pp->geom->softc;
291 	/*
292 	 * If sc == NULL, provider's error should be set and g_concat_start()
293 	 * should not be called at all.
294 	 */
295 	KASSERT(sc != NULL,
296 	    ("Provider's error should be set (error=%d)(device=%s).",
297 	    bp->bio_to->error, bp->bio_to->name));
298 
299 	G_CONCAT_LOGREQ(bp, "Request received.");
300 
301 	switch (bp->bio_cmd) {
302 	case BIO_READ:
303 	case BIO_WRITE:
304 	case BIO_DELETE:
305 		break;
306 	case BIO_FLUSH:
307 		g_concat_flush(sc, bp);
308 		return;
309 	case BIO_GETATTR:
310 		if (strcmp("GEOM::kerneldump", bp->bio_attribute) == 0) {
311 			g_concat_kernel_dump(bp);
312 			return;
313 		}
314 		/* To which provider it should be delivered? */
315 		/* FALLTHROUGH */
316 	default:
317 		g_io_deliver(bp, EOPNOTSUPP);
318 		return;
319 	}
320 
321 	offset = bp->bio_offset;
322 	length = bp->bio_length;
323 	addr = bp->bio_data;
324 	end = offset + length;
325 
326 	bioq_init(&queue);
327 	for (no = 0; no < sc->sc_ndisks; no++) {
328 		disk = &sc->sc_disks[no];
329 		if (disk->d_end <= offset)
330 			continue;
331 		if (disk->d_start >= end)
332 			break;
333 
334 		off = offset - disk->d_start;
335 		len = MIN(length, disk->d_end - offset);
336 		length -= len;
337 		offset += len;
338 
339 		cbp = g_clone_bio(bp);
340 		if (cbp == NULL) {
341 			for (cbp = bioq_first(&queue); cbp != NULL;
342 			    cbp = bioq_first(&queue)) {
343 				bioq_remove(&queue, cbp);
344 				g_destroy_bio(cbp);
345 			}
346 			if (bp->bio_error == 0)
347 				bp->bio_error = ENOMEM;
348 			g_io_deliver(bp, bp->bio_error);
349 			return;
350 		}
351 		bioq_insert_tail(&queue, cbp);
352 		/*
353 		 * Fill in the component buf structure.
354 		 */
355 		cbp->bio_done = g_std_done;
356 		cbp->bio_offset = off;
357 		cbp->bio_data = addr;
358 		addr += len;
359 		cbp->bio_length = len;
360 		cbp->bio_to = disk->d_consumer->provider;
361 		cbp->bio_caller1 = disk;
362 
363 		if (length == 0)
364 			break;
365 	}
366 	KASSERT(length == 0,
367 	    ("Length is still greater than 0 (class=%s, name=%s).",
368 	    bp->bio_to->geom->class->name, bp->bio_to->geom->name));
369 	for (cbp = bioq_first(&queue); cbp != NULL; cbp = bioq_first(&queue)) {
370 		bioq_remove(&queue, cbp);
371 		G_CONCAT_LOGREQ(cbp, "Sending request.");
372 		disk = cbp->bio_caller1;
373 		cbp->bio_caller1 = NULL;
374 		g_io_request(cbp, disk->d_consumer);
375 	}
376 }
377 
378 static void
379 g_concat_check_and_run(struct g_concat_softc *sc)
380 {
381 	struct g_concat_disk *disk;
382 	struct g_provider *pp;
383 	u_int no, sectorsize = 0;
384 	off_t start;
385 
386 	g_topology_assert();
387 	if (g_concat_nvalid(sc) != sc->sc_ndisks)
388 		return;
389 
390 	pp = g_new_providerf(sc->sc_geom, "concat/%s", sc->sc_name);
391 	start = 0;
392 	for (no = 0; no < sc->sc_ndisks; no++) {
393 		disk = &sc->sc_disks[no];
394 		disk->d_start = start;
395 		disk->d_end = disk->d_start +
396 		    disk->d_consumer->provider->mediasize;
397 		if (sc->sc_type == G_CONCAT_TYPE_AUTOMATIC)
398 			disk->d_end -= disk->d_consumer->provider->sectorsize;
399 		start = disk->d_end;
400 		if (no == 0)
401 			sectorsize = disk->d_consumer->provider->sectorsize;
402 		else {
403 			sectorsize = lcm(sectorsize,
404 			    disk->d_consumer->provider->sectorsize);
405 		}
406 	}
407 	pp->sectorsize = sectorsize;
408 	/* We have sc->sc_disks[sc->sc_ndisks - 1].d_end in 'start'. */
409 	pp->mediasize = start;
410 	pp->stripesize = sc->sc_disks[0].d_consumer->provider->stripesize;
411 	pp->stripeoffset = sc->sc_disks[0].d_consumer->provider->stripeoffset;
412 	sc->sc_provider = pp;
413 	g_error_provider(pp, 0);
414 
415 	G_CONCAT_DEBUG(0, "Device %s activated.", sc->sc_provider->name);
416 }
417 
418 static int
419 g_concat_read_metadata(struct g_consumer *cp, struct g_concat_metadata *md)
420 {
421 	struct g_provider *pp;
422 	u_char *buf;
423 	int error;
424 
425 	g_topology_assert();
426 
427 	error = g_access(cp, 1, 0, 0);
428 	if (error != 0)
429 		return (error);
430 	pp = cp->provider;
431 	g_topology_unlock();
432 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
433 	    &error);
434 	g_topology_lock();
435 	g_access(cp, -1, 0, 0);
436 	if (buf == NULL)
437 		return (error);
438 
439 	/* Decode metadata. */
440 	concat_metadata_decode(buf, md);
441 	g_free(buf);
442 
443 	return (0);
444 }
445 
446 /*
447  * Add disk to given device.
448  */
449 static int
450 g_concat_add_disk(struct g_concat_softc *sc, struct g_provider *pp, u_int no)
451 {
452 	struct g_concat_disk *disk;
453 	struct g_consumer *cp, *fcp;
454 	struct g_geom *gp;
455 	int error;
456 
457 	g_topology_assert();
458 	/* Metadata corrupted? */
459 	if (no >= sc->sc_ndisks)
460 		return (EINVAL);
461 
462 	disk = &sc->sc_disks[no];
463 	/* Check if disk is not already attached. */
464 	if (disk->d_consumer != NULL)
465 		return (EEXIST);
466 
467 	gp = sc->sc_geom;
468 	fcp = LIST_FIRST(&gp->consumer);
469 
470 	cp = g_new_consumer(gp);
471 	error = g_attach(cp, pp);
472 	if (error != 0) {
473 		g_destroy_consumer(cp);
474 		return (error);
475 	}
476 
477 	if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0)) {
478 		error = g_access(cp, fcp->acr, fcp->acw, fcp->ace);
479 		if (error != 0) {
480 			g_detach(cp);
481 			g_destroy_consumer(cp);
482 			return (error);
483 		}
484 	}
485 	if (sc->sc_type == G_CONCAT_TYPE_AUTOMATIC) {
486 		struct g_concat_metadata md;
487 
488 		/* Re-read metadata. */
489 		error = g_concat_read_metadata(cp, &md);
490 		if (error != 0)
491 			goto fail;
492 
493 		if (strcmp(md.md_magic, G_CONCAT_MAGIC) != 0 ||
494 		    strcmp(md.md_name, sc->sc_name) != 0 ||
495 		    md.md_id != sc->sc_id) {
496 			G_CONCAT_DEBUG(0, "Metadata on %s changed.", pp->name);
497 			goto fail;
498 		}
499 	}
500 
501 	cp->private = disk;
502 	disk->d_consumer = cp;
503 	disk->d_softc = sc;
504 	disk->d_start = 0;	/* not yet */
505 	disk->d_end = 0;	/* not yet */
506 	disk->d_removed = 0;
507 
508 	G_CONCAT_DEBUG(0, "Disk %s attached to %s.", pp->name, sc->sc_name);
509 
510 	g_concat_check_and_run(sc);
511 
512 	return (0);
513 fail:
514 	if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0))
515 		g_access(cp, -fcp->acr, -fcp->acw, -fcp->ace);
516 	g_detach(cp);
517 	g_destroy_consumer(cp);
518 	return (error);
519 }
520 
521 static struct g_geom *
522 g_concat_create(struct g_class *mp, const struct g_concat_metadata *md,
523     u_int type)
524 {
525 	struct g_concat_softc *sc;
526 	struct g_geom *gp;
527 	u_int no;
528 
529 	G_CONCAT_DEBUG(1, "Creating device %s (id=%u).", md->md_name,
530 	    md->md_id);
531 
532 	/* One disks is minimum. */
533 	if (md->md_all < 1)
534 		return (NULL);
535 
536 	/* Check for duplicate unit */
537 	LIST_FOREACH(gp, &mp->geom, geom) {
538 		sc = gp->softc;
539 		if (sc != NULL && strcmp(sc->sc_name, md->md_name) == 0) {
540 			G_CONCAT_DEBUG(0, "Device %s already configured.",
541 			    gp->name);
542 			return (NULL);
543 		}
544 	}
545 	gp = g_new_geomf(mp, "%s", md->md_name);
546 	sc = malloc(sizeof(*sc), M_CONCAT, M_WAITOK | M_ZERO);
547 	gp->start = g_concat_start;
548 	gp->spoiled = g_concat_orphan;
549 	gp->orphan = g_concat_orphan;
550 	gp->access = g_concat_access;
551 	gp->dumpconf = g_concat_dumpconf;
552 
553 	sc->sc_id = md->md_id;
554 	sc->sc_ndisks = md->md_all;
555 	sc->sc_disks = malloc(sizeof(struct g_concat_disk) * sc->sc_ndisks,
556 	    M_CONCAT, M_WAITOK | M_ZERO);
557 	for (no = 0; no < sc->sc_ndisks; no++)
558 		sc->sc_disks[no].d_consumer = NULL;
559 	sc->sc_type = type;
560 
561 	gp->softc = sc;
562 	sc->sc_geom = gp;
563 	sc->sc_provider = NULL;
564 
565 	G_CONCAT_DEBUG(0, "Device %s created (id=%u).", sc->sc_name, sc->sc_id);
566 
567 	return (gp);
568 }
569 
570 static int
571 g_concat_destroy(struct g_concat_softc *sc, boolean_t force)
572 {
573 	struct g_provider *pp;
574 	struct g_consumer *cp, *cp1;
575 	struct g_geom *gp;
576 
577 	g_topology_assert();
578 
579 	if (sc == NULL)
580 		return (ENXIO);
581 
582 	pp = sc->sc_provider;
583 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
584 		if (force) {
585 			G_CONCAT_DEBUG(0, "Device %s is still open, so it "
586 			    "can't be definitely removed.", pp->name);
587 		} else {
588 			G_CONCAT_DEBUG(1,
589 			    "Device %s is still open (r%dw%de%d).", pp->name,
590 			    pp->acr, pp->acw, pp->ace);
591 			return (EBUSY);
592 		}
593 	}
594 
595 	gp = sc->sc_geom;
596 	LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp1) {
597 		g_concat_remove_disk(cp->private);
598 		if (cp1 == NULL)
599 			return (0);	/* Recursion happened. */
600 	}
601 	if (!LIST_EMPTY(&gp->consumer))
602 		return (EINPROGRESS);
603 
604 	gp->softc = NULL;
605 	KASSERT(sc->sc_provider == NULL, ("Provider still exists? (device=%s)",
606 	    gp->name));
607 	free(sc->sc_disks, M_CONCAT);
608 	free(sc, M_CONCAT);
609 
610 	G_CONCAT_DEBUG(0, "Device %s destroyed.", gp->name);
611 	g_wither_geom(gp, ENXIO);
612 	return (0);
613 }
614 
615 static int
616 g_concat_destroy_geom(struct gctl_req *req __unused,
617     struct g_class *mp __unused, struct g_geom *gp)
618 {
619 	struct g_concat_softc *sc;
620 
621 	sc = gp->softc;
622 	return (g_concat_destroy(sc, 0));
623 }
624 
625 static struct g_geom *
626 g_concat_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
627 {
628 	struct g_concat_metadata md;
629 	struct g_concat_softc *sc;
630 	struct g_consumer *cp;
631 	struct g_geom *gp;
632 	int error;
633 
634 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
635 	g_topology_assert();
636 
637 	/* Skip providers that are already open for writing. */
638 	if (pp->acw > 0)
639 		return (NULL);
640 
641 	G_CONCAT_DEBUG(3, "Tasting %s.", pp->name);
642 
643 	gp = g_new_geomf(mp, "concat:taste");
644 	gp->start = g_concat_start;
645 	gp->access = g_concat_access;
646 	gp->orphan = g_concat_orphan;
647 	cp = g_new_consumer(gp);
648 	g_attach(cp, pp);
649 	error = g_concat_read_metadata(cp, &md);
650 	g_detach(cp);
651 	g_destroy_consumer(cp);
652 	g_destroy_geom(gp);
653 	if (error != 0)
654 		return (NULL);
655 	gp = NULL;
656 
657 	if (strcmp(md.md_magic, G_CONCAT_MAGIC) != 0)
658 		return (NULL);
659 	if (md.md_version > G_CONCAT_VERSION) {
660 		printf("geom_concat.ko module is too old to handle %s.\n",
661 		    pp->name);
662 		return (NULL);
663 	}
664 	/*
665 	 * Backward compatibility:
666 	 */
667 	/* There was no md_provider field in earlier versions of metadata. */
668 	if (md.md_version < 3)
669 		bzero(md.md_provider, sizeof(md.md_provider));
670 	/* There was no md_provsize field in earlier versions of metadata. */
671 	if (md.md_version < 4)
672 		md.md_provsize = pp->mediasize;
673 
674 	if (md.md_provider[0] != '\0' &&
675 	    !g_compare_names(md.md_provider, pp->name))
676 		return (NULL);
677 	if (md.md_provsize != pp->mediasize)
678 		return (NULL);
679 
680 	/*
681 	 * Let's check if device already exists.
682 	 */
683 	sc = NULL;
684 	LIST_FOREACH(gp, &mp->geom, geom) {
685 		sc = gp->softc;
686 		if (sc == NULL)
687 			continue;
688 		if (sc->sc_type != G_CONCAT_TYPE_AUTOMATIC)
689 			continue;
690 		if (strcmp(md.md_name, sc->sc_name) != 0)
691 			continue;
692 		if (md.md_id != sc->sc_id)
693 			continue;
694 		break;
695 	}
696 	if (gp != NULL) {
697 		G_CONCAT_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
698 		error = g_concat_add_disk(sc, pp, md.md_no);
699 		if (error != 0) {
700 			G_CONCAT_DEBUG(0,
701 			    "Cannot add disk %s to %s (error=%d).", pp->name,
702 			    gp->name, error);
703 			return (NULL);
704 		}
705 	} else {
706 		gp = g_concat_create(mp, &md, G_CONCAT_TYPE_AUTOMATIC);
707 		if (gp == NULL) {
708 			G_CONCAT_DEBUG(0, "Cannot create device %s.",
709 			    md.md_name);
710 			return (NULL);
711 		}
712 		sc = gp->softc;
713 		G_CONCAT_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
714 		error = g_concat_add_disk(sc, pp, md.md_no);
715 		if (error != 0) {
716 			G_CONCAT_DEBUG(0,
717 			    "Cannot add disk %s to %s (error=%d).", pp->name,
718 			    gp->name, error);
719 			g_concat_destroy(sc, 1);
720 			return (NULL);
721 		}
722 	}
723 
724 	return (gp);
725 }
726 
727 static void
728 g_concat_ctl_create(struct gctl_req *req, struct g_class *mp)
729 {
730 	u_int attached, no;
731 	struct g_concat_metadata md;
732 	struct g_provider *pp;
733 	struct g_concat_softc *sc;
734 	struct g_geom *gp;
735 	struct sbuf *sb;
736 	const char *name;
737 	char param[16];
738 	int *nargs;
739 
740 	g_topology_assert();
741 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
742 	if (nargs == NULL) {
743 		gctl_error(req, "No '%s' argument.", "nargs");
744 		return;
745 	}
746 	if (*nargs < 2) {
747 		gctl_error(req, "Too few arguments.");
748 		return;
749 	}
750 
751 	strlcpy(md.md_magic, G_CONCAT_MAGIC, sizeof(md.md_magic));
752 	md.md_version = G_CONCAT_VERSION;
753 	name = gctl_get_asciiparam(req, "arg0");
754 	if (name == NULL) {
755 		gctl_error(req, "No 'arg%u' argument.", 0);
756 		return;
757 	}
758 	strlcpy(md.md_name, name, sizeof(md.md_name));
759 	md.md_id = arc4random();
760 	md.md_no = 0;
761 	md.md_all = *nargs - 1;
762 	bzero(md.md_provider, sizeof(md.md_provider));
763 	/* This field is not important here. */
764 	md.md_provsize = 0;
765 
766 	/* Check all providers are valid */
767 	for (no = 1; no < *nargs; no++) {
768 		snprintf(param, sizeof(param), "arg%u", no);
769 		name = gctl_get_asciiparam(req, param);
770 		if (name == NULL) {
771 			gctl_error(req, "No 'arg%u' argument.", no);
772 			return;
773 		}
774 		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
775 			name += strlen("/dev/");
776 		pp = g_provider_by_name(name);
777 		if (pp == NULL) {
778 			G_CONCAT_DEBUG(1, "Disk %s is invalid.", name);
779 			gctl_error(req, "Disk %s is invalid.", name);
780 			return;
781 		}
782 	}
783 
784 	gp = g_concat_create(mp, &md, G_CONCAT_TYPE_MANUAL);
785 	if (gp == NULL) {
786 		gctl_error(req, "Can't configure %s.", md.md_name);
787 		return;
788 	}
789 
790 	sc = gp->softc;
791 	sb = sbuf_new_auto();
792 	sbuf_printf(sb, "Can't attach disk(s) to %s:", gp->name);
793 	for (attached = 0, no = 1; no < *nargs; no++) {
794 		snprintf(param, sizeof(param), "arg%u", no);
795 		name = gctl_get_asciiparam(req, param);
796 		if (name == NULL) {
797 			gctl_error(req, "No 'arg%d' argument.", no);
798 			return;
799 		}
800 		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
801 			name += strlen("/dev/");
802 		pp = g_provider_by_name(name);
803 		KASSERT(pp != NULL, ("Provider %s disappear?!", name));
804 		if (g_concat_add_disk(sc, pp, no - 1) != 0) {
805 			G_CONCAT_DEBUG(1, "Disk %u (%s) not attached to %s.",
806 			    no, pp->name, gp->name);
807 			sbuf_printf(sb, " %s", pp->name);
808 			continue;
809 		}
810 		attached++;
811 	}
812 	sbuf_finish(sb);
813 	if (md.md_all != attached) {
814 		g_concat_destroy(gp->softc, 1);
815 		gctl_error(req, "%s", sbuf_data(sb));
816 	}
817 	sbuf_delete(sb);
818 }
819 
820 static struct g_concat_softc *
821 g_concat_find_device(struct g_class *mp, const char *name)
822 {
823 	struct g_concat_softc *sc;
824 	struct g_geom *gp;
825 
826 	LIST_FOREACH(gp, &mp->geom, geom) {
827 		sc = gp->softc;
828 		if (sc == NULL)
829 			continue;
830 		if (strcmp(sc->sc_name, name) == 0)
831 			return (sc);
832 	}
833 	return (NULL);
834 }
835 
836 static void
837 g_concat_ctl_destroy(struct gctl_req *req, struct g_class *mp)
838 {
839 	struct g_concat_softc *sc;
840 	int *force, *nargs, error;
841 	const char *name;
842 	char param[16];
843 	u_int i;
844 
845 	g_topology_assert();
846 
847 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
848 	if (nargs == NULL) {
849 		gctl_error(req, "No '%s' argument.", "nargs");
850 		return;
851 	}
852 	if (*nargs <= 0) {
853 		gctl_error(req, "Missing device(s).");
854 		return;
855 	}
856 	force = gctl_get_paraml(req, "force", sizeof(*force));
857 	if (force == NULL) {
858 		gctl_error(req, "No '%s' argument.", "force");
859 		return;
860 	}
861 
862 	for (i = 0; i < (u_int)*nargs; i++) {
863 		snprintf(param, sizeof(param), "arg%u", i);
864 		name = gctl_get_asciiparam(req, param);
865 		if (name == NULL) {
866 			gctl_error(req, "No 'arg%u' argument.", i);
867 			return;
868 		}
869 		sc = g_concat_find_device(mp, name);
870 		if (sc == NULL) {
871 			gctl_error(req, "No such device: %s.", name);
872 			return;
873 		}
874 		error = g_concat_destroy(sc, *force);
875 		if (error != 0) {
876 			gctl_error(req, "Cannot destroy device %s (error=%d).",
877 			    sc->sc_name, error);
878 			return;
879 		}
880 	}
881 }
882 
883 static void
884 g_concat_config(struct gctl_req *req, struct g_class *mp, const char *verb)
885 {
886 	uint32_t *version;
887 
888 	g_topology_assert();
889 
890 	version = gctl_get_paraml(req, "version", sizeof(*version));
891 	if (version == NULL) {
892 		gctl_error(req, "No '%s' argument.", "version");
893 		return;
894 	}
895 	if (*version != G_CONCAT_VERSION) {
896 		gctl_error(req, "Userland and kernel parts are out of sync.");
897 		return;
898 	}
899 
900 	if (strcmp(verb, "create") == 0) {
901 		g_concat_ctl_create(req, mp);
902 		return;
903 	} else if (strcmp(verb, "destroy") == 0 ||
904 	    strcmp(verb, "stop") == 0) {
905 		g_concat_ctl_destroy(req, mp);
906 		return;
907 	}
908 	gctl_error(req, "Unknown verb.");
909 }
910 
911 static void
912 g_concat_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
913     struct g_consumer *cp, struct g_provider *pp)
914 {
915 	struct g_concat_softc *sc;
916 
917 	g_topology_assert();
918 	sc = gp->softc;
919 	if (sc == NULL)
920 		return;
921 	if (pp != NULL) {
922 		/* Nothing here. */
923 	} else if (cp != NULL) {
924 		struct g_concat_disk *disk;
925 
926 		disk = cp->private;
927 		if (disk == NULL)
928 			return;
929 		sbuf_printf(sb, "%s<End>%jd</End>\n", indent,
930 		    (intmax_t)disk->d_end);
931 		sbuf_printf(sb, "%s<Start>%jd</Start>\n", indent,
932 		    (intmax_t)disk->d_start);
933 	} else {
934 		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
935 		sbuf_printf(sb, "%s<Type>", indent);
936 		switch (sc->sc_type) {
937 		case G_CONCAT_TYPE_AUTOMATIC:
938 			sbuf_printf(sb, "AUTOMATIC");
939 			break;
940 		case G_CONCAT_TYPE_MANUAL:
941 			sbuf_printf(sb, "MANUAL");
942 			break;
943 		default:
944 			sbuf_printf(sb, "UNKNOWN");
945 			break;
946 		}
947 		sbuf_printf(sb, "</Type>\n");
948 		sbuf_printf(sb, "%s<Status>Total=%u, Online=%u</Status>\n",
949 		    indent, sc->sc_ndisks, g_concat_nvalid(sc));
950 		sbuf_printf(sb, "%s<State>", indent);
951 		if (sc->sc_provider != NULL && sc->sc_provider->error == 0)
952 			sbuf_printf(sb, "UP");
953 		else
954 			sbuf_printf(sb, "DOWN");
955 		sbuf_printf(sb, "</State>\n");
956 	}
957 }
958 
959 DECLARE_GEOM_CLASS(g_concat_class, g_concat);
960