xref: /freebsd/sys/geom/concat/g_concat.c (revision fe2494903422ba3b924eba82cb63a6a9188fad7a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2004-2005 Pawel Jakub Dawidek <pjd@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/module.h>
36 #include <sys/lock.h>
37 #include <sys/mutex.h>
38 #include <sys/bio.h>
39 #include <sys/sbuf.h>
40 #include <sys/sysctl.h>
41 #include <sys/malloc.h>
42 #include <geom/geom.h>
43 #include <geom/concat/g_concat.h>
44 
45 FEATURE(geom_concat, "GEOM concatenation support");
46 
47 static MALLOC_DEFINE(M_CONCAT, "concat_data", "GEOM_CONCAT Data");
48 
49 SYSCTL_DECL(_kern_geom);
50 static SYSCTL_NODE(_kern_geom, OID_AUTO, concat, CTLFLAG_RW, 0,
51     "GEOM_CONCAT stuff");
52 static u_int g_concat_debug = 0;
53 SYSCTL_UINT(_kern_geom_concat, OID_AUTO, debug, CTLFLAG_RWTUN, &g_concat_debug, 0,
54     "Debug level");
55 
56 static int g_concat_destroy(struct g_concat_softc *sc, boolean_t force);
57 static int g_concat_destroy_geom(struct gctl_req *req, struct g_class *mp,
58     struct g_geom *gp);
59 
60 static g_taste_t g_concat_taste;
61 static g_ctl_req_t g_concat_config;
62 static g_dumpconf_t g_concat_dumpconf;
63 
64 struct g_class g_concat_class = {
65 	.name = G_CONCAT_CLASS_NAME,
66 	.version = G_VERSION,
67 	.ctlreq = g_concat_config,
68 	.taste = g_concat_taste,
69 	.destroy_geom = g_concat_destroy_geom
70 };
71 
72 
73 /*
74  * Greatest Common Divisor.
75  */
76 static u_int
77 gcd(u_int a, u_int b)
78 {
79 	u_int c;
80 
81 	while (b != 0) {
82 		c = a;
83 		a = b;
84 		b = (c % b);
85 	}
86 	return (a);
87 }
88 
89 /*
90  * Least Common Multiple.
91  */
92 static u_int
93 lcm(u_int a, u_int b)
94 {
95 
96 	return ((a * b) / gcd(a, b));
97 }
98 
99 /*
100  * Return the number of valid disks.
101  */
102 static u_int
103 g_concat_nvalid(struct g_concat_softc *sc)
104 {
105 	u_int i, no;
106 
107 	no = 0;
108 	for (i = 0; i < sc->sc_ndisks; i++) {
109 		if (sc->sc_disks[i].d_consumer != NULL)
110 			no++;
111 	}
112 
113 	return (no);
114 }
115 
116 static void
117 g_concat_remove_disk(struct g_concat_disk *disk)
118 {
119 	struct g_consumer *cp;
120 	struct g_concat_softc *sc;
121 
122 	g_topology_assert();
123 	KASSERT(disk->d_consumer != NULL, ("Non-valid disk in %s.", __func__));
124 	sc = disk->d_softc;
125 	cp = disk->d_consumer;
126 
127 	if (!disk->d_removed) {
128 		G_CONCAT_DEBUG(0, "Disk %s removed from %s.",
129 		    cp->provider->name, sc->sc_name);
130 		disk->d_removed = 1;
131 	}
132 
133 	if (sc->sc_provider != NULL) {
134 		G_CONCAT_DEBUG(0, "Device %s deactivated.",
135 		    sc->sc_provider->name);
136 		g_wither_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_candelete(struct bio *bp)
210 {
211 	struct g_concat_softc *sc;
212 	struct g_concat_disk *disk;
213 	int i, *val;
214 
215 	val = (int *)bp->bio_data;
216 	*val = 0;
217 
218 	sc = bp->bio_to->geom->softc;
219 	for (i = 0; i < sc->sc_ndisks; i++) {
220 		disk = &sc->sc_disks[i];
221 		if (!disk->d_removed && disk->d_candelete) {
222 			*val = 1;
223 			break;
224 		}
225 	}
226 	g_io_deliver(bp, 0);
227 }
228 
229 static void
230 g_concat_kernel_dump(struct bio *bp)
231 {
232 	struct g_concat_softc *sc;
233 	struct g_concat_disk *disk;
234 	struct bio *cbp;
235 	struct g_kerneldump *gkd;
236 	u_int i;
237 
238 	sc = bp->bio_to->geom->softc;
239 	gkd = (struct g_kerneldump *)bp->bio_data;
240 	for (i = 0; i < sc->sc_ndisks; i++) {
241 		if (sc->sc_disks[i].d_start <= gkd->offset &&
242 		    sc->sc_disks[i].d_end > gkd->offset)
243 			break;
244 	}
245 	if (i == sc->sc_ndisks)
246 		g_io_deliver(bp, EOPNOTSUPP);
247 	disk = &sc->sc_disks[i];
248 	gkd->offset -= disk->d_start;
249 	if (gkd->length > disk->d_end - disk->d_start - gkd->offset)
250 		gkd->length = disk->d_end - disk->d_start - gkd->offset;
251 	cbp = g_clone_bio(bp);
252 	if (cbp == NULL) {
253 		g_io_deliver(bp, ENOMEM);
254 		return;
255 	}
256 	cbp->bio_done = g_std_done;
257 	g_io_request(cbp, disk->d_consumer);
258 	G_CONCAT_DEBUG(1, "Kernel dump will go to %s.",
259 	    disk->d_consumer->provider->name);
260 }
261 
262 static void
263 g_concat_done(struct bio *bp)
264 {
265 	struct g_concat_softc *sc;
266 	struct bio *pbp;
267 
268 	pbp = bp->bio_parent;
269 	sc = pbp->bio_to->geom->softc;
270 	mtx_lock(&sc->sc_lock);
271 	if (pbp->bio_error == 0)
272 		pbp->bio_error = bp->bio_error;
273 	pbp->bio_completed += bp->bio_completed;
274 	pbp->bio_inbed++;
275 	if (pbp->bio_children == pbp->bio_inbed) {
276 		mtx_unlock(&sc->sc_lock);
277 		g_io_deliver(pbp, pbp->bio_error);
278 	} else
279 		mtx_unlock(&sc->sc_lock);
280 	g_destroy_bio(bp);
281 }
282 
283 static void
284 g_concat_flush(struct g_concat_softc *sc, struct bio *bp)
285 {
286 	struct bio_queue_head queue;
287 	struct g_consumer *cp;
288 	struct bio *cbp;
289 	u_int no;
290 
291 	bioq_init(&queue);
292 	for (no = 0; no < sc->sc_ndisks; no++) {
293 		cbp = g_clone_bio(bp);
294 		if (cbp == NULL) {
295 			while ((cbp = bioq_takefirst(&queue)) != NULL)
296 				g_destroy_bio(cbp);
297 			if (bp->bio_error == 0)
298 				bp->bio_error = ENOMEM;
299 			g_io_deliver(bp, bp->bio_error);
300 			return;
301 		}
302 		bioq_insert_tail(&queue, cbp);
303 		cbp->bio_done = g_concat_done;
304 		cbp->bio_caller1 = sc->sc_disks[no].d_consumer;
305 		cbp->bio_to = sc->sc_disks[no].d_consumer->provider;
306 	}
307 	while ((cbp = bioq_takefirst(&queue)) != NULL) {
308 		G_CONCAT_LOGREQ(cbp, "Sending request.");
309 		cp = cbp->bio_caller1;
310 		cbp->bio_caller1 = NULL;
311 		g_io_request(cbp, cp);
312 	}
313 }
314 
315 static void
316 g_concat_start(struct bio *bp)
317 {
318 	struct bio_queue_head queue;
319 	struct g_concat_softc *sc;
320 	struct g_concat_disk *disk;
321 	struct g_provider *pp;
322 	off_t offset, end, length, off, len;
323 	struct bio *cbp;
324 	char *addr;
325 	u_int no;
326 
327 	pp = bp->bio_to;
328 	sc = pp->geom->softc;
329 	/*
330 	 * If sc == NULL, provider's error should be set and g_concat_start()
331 	 * should not be called at all.
332 	 */
333 	KASSERT(sc != NULL,
334 	    ("Provider's error should be set (error=%d)(device=%s).",
335 	    bp->bio_to->error, bp->bio_to->name));
336 
337 	G_CONCAT_LOGREQ(bp, "Request received.");
338 
339 	switch (bp->bio_cmd) {
340 	case BIO_READ:
341 	case BIO_WRITE:
342 	case BIO_DELETE:
343 		break;
344 	case BIO_FLUSH:
345 		g_concat_flush(sc, bp);
346 		return;
347 	case BIO_GETATTR:
348 		if (strcmp("GEOM::kerneldump", bp->bio_attribute) == 0) {
349 			g_concat_kernel_dump(bp);
350 			return;
351 		} else if (strcmp("GEOM::candelete", bp->bio_attribute) == 0) {
352 			g_concat_candelete(bp);
353 			return;
354 		}
355 		/* To which provider it should be delivered? */
356 		/* FALLTHROUGH */
357 	default:
358 		g_io_deliver(bp, EOPNOTSUPP);
359 		return;
360 	}
361 
362 	offset = bp->bio_offset;
363 	length = bp->bio_length;
364 	if ((bp->bio_flags & BIO_UNMAPPED) != 0)
365 		addr = NULL;
366 	else
367 		addr = bp->bio_data;
368 	end = offset + length;
369 
370 	bioq_init(&queue);
371 	for (no = 0; no < sc->sc_ndisks; no++) {
372 		disk = &sc->sc_disks[no];
373 		if (disk->d_end <= offset)
374 			continue;
375 		if (disk->d_start >= end)
376 			break;
377 
378 		off = offset - disk->d_start;
379 		len = MIN(length, disk->d_end - offset);
380 		length -= len;
381 		offset += len;
382 
383 		cbp = g_clone_bio(bp);
384 		if (cbp == NULL) {
385 			while ((cbp = bioq_takefirst(&queue)) != NULL)
386 				g_destroy_bio(cbp);
387 			if (bp->bio_error == 0)
388 				bp->bio_error = ENOMEM;
389 			g_io_deliver(bp, bp->bio_error);
390 			return;
391 		}
392 		bioq_insert_tail(&queue, cbp);
393 		/*
394 		 * Fill in the component buf structure.
395 		 */
396 		if (len == bp->bio_length)
397 			cbp->bio_done = g_std_done;
398 		else
399 			cbp->bio_done = g_concat_done;
400 		cbp->bio_offset = off;
401 		cbp->bio_length = len;
402 		if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
403 			cbp->bio_ma_offset += (uintptr_t)addr;
404 			cbp->bio_ma += cbp->bio_ma_offset / PAGE_SIZE;
405 			cbp->bio_ma_offset %= PAGE_SIZE;
406 			cbp->bio_ma_n = round_page(cbp->bio_ma_offset +
407 			    cbp->bio_length) / PAGE_SIZE;
408 		} else
409 			cbp->bio_data = addr;
410 		addr += len;
411 		cbp->bio_to = disk->d_consumer->provider;
412 		cbp->bio_caller1 = disk;
413 
414 		if (length == 0)
415 			break;
416 	}
417 	KASSERT(length == 0,
418 	    ("Length is still greater than 0 (class=%s, name=%s).",
419 	    bp->bio_to->geom->class->name, bp->bio_to->geom->name));
420 	while ((cbp = bioq_takefirst(&queue)) != NULL) {
421 		G_CONCAT_LOGREQ(cbp, "Sending request.");
422 		disk = cbp->bio_caller1;
423 		cbp->bio_caller1 = NULL;
424 		g_io_request(cbp, disk->d_consumer);
425 	}
426 }
427 
428 static void
429 g_concat_check_and_run(struct g_concat_softc *sc)
430 {
431 	struct g_concat_disk *disk;
432 	struct g_provider *dp, *pp;
433 	u_int no, sectorsize = 0;
434 	off_t start;
435 	int error;
436 
437 	g_topology_assert();
438 	if (g_concat_nvalid(sc) != sc->sc_ndisks)
439 		return;
440 
441 	pp = g_new_providerf(sc->sc_geom, "concat/%s", sc->sc_name);
442 	pp->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE |
443 	    G_PF_ACCEPT_UNMAPPED;
444 	start = 0;
445 	for (no = 0; no < sc->sc_ndisks; no++) {
446 		disk = &sc->sc_disks[no];
447 		dp = disk->d_consumer->provider;
448 		disk->d_start = start;
449 		disk->d_end = disk->d_start + dp->mediasize;
450 		if (sc->sc_type == G_CONCAT_TYPE_AUTOMATIC)
451 			disk->d_end -= dp->sectorsize;
452 		start = disk->d_end;
453 		error = g_access(disk->d_consumer, 1, 0, 0);
454 		if (error == 0) {
455 			error = g_getattr("GEOM::candelete", disk->d_consumer,
456 			    &disk->d_candelete);
457 			if (error != 0)
458 				disk->d_candelete = 0;
459 			(void)g_access(disk->d_consumer, -1, 0, 0);
460 		} else
461 			G_CONCAT_DEBUG(1, "Failed to access disk %s, error %d.",
462 			    dp->name, error);
463 		if (no == 0)
464 			sectorsize = dp->sectorsize;
465 		else
466 			sectorsize = lcm(sectorsize, dp->sectorsize);
467 
468 		/* A provider underneath us doesn't support unmapped */
469 		if ((dp->flags & G_PF_ACCEPT_UNMAPPED) == 0) {
470 			G_CONCAT_DEBUG(1, "Cancelling unmapped "
471 			    "because of %s.", dp->name);
472 			pp->flags &= ~G_PF_ACCEPT_UNMAPPED;
473 		}
474 	}
475 	pp->sectorsize = sectorsize;
476 	/* We have sc->sc_disks[sc->sc_ndisks - 1].d_end in 'start'. */
477 	pp->mediasize = start;
478 	pp->stripesize = sc->sc_disks[0].d_consumer->provider->stripesize;
479 	pp->stripeoffset = sc->sc_disks[0].d_consumer->provider->stripeoffset;
480 	sc->sc_provider = pp;
481 	g_error_provider(pp, 0);
482 
483 	G_CONCAT_DEBUG(0, "Device %s activated.", sc->sc_provider->name);
484 }
485 
486 static int
487 g_concat_read_metadata(struct g_consumer *cp, struct g_concat_metadata *md)
488 {
489 	struct g_provider *pp;
490 	u_char *buf;
491 	int error;
492 
493 	g_topology_assert();
494 
495 	error = g_access(cp, 1, 0, 0);
496 	if (error != 0)
497 		return (error);
498 	pp = cp->provider;
499 	g_topology_unlock();
500 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
501 	    &error);
502 	g_topology_lock();
503 	g_access(cp, -1, 0, 0);
504 	if (buf == NULL)
505 		return (error);
506 
507 	/* Decode metadata. */
508 	concat_metadata_decode(buf, md);
509 	g_free(buf);
510 
511 	return (0);
512 }
513 
514 /*
515  * Add disk to given device.
516  */
517 static int
518 g_concat_add_disk(struct g_concat_softc *sc, struct g_provider *pp, u_int no)
519 {
520 	struct g_concat_disk *disk;
521 	struct g_consumer *cp, *fcp;
522 	struct g_geom *gp;
523 	int error;
524 
525 	g_topology_assert();
526 	/* Metadata corrupted? */
527 	if (no >= sc->sc_ndisks)
528 		return (EINVAL);
529 
530 	disk = &sc->sc_disks[no];
531 	/* Check if disk is not already attached. */
532 	if (disk->d_consumer != NULL)
533 		return (EEXIST);
534 
535 	gp = sc->sc_geom;
536 	fcp = LIST_FIRST(&gp->consumer);
537 
538 	cp = g_new_consumer(gp);
539 	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
540 	error = g_attach(cp, pp);
541 	if (error != 0) {
542 		g_destroy_consumer(cp);
543 		return (error);
544 	}
545 
546 	if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0)) {
547 		error = g_access(cp, fcp->acr, fcp->acw, fcp->ace);
548 		if (error != 0) {
549 			g_detach(cp);
550 			g_destroy_consumer(cp);
551 			return (error);
552 		}
553 	}
554 	if (sc->sc_type == G_CONCAT_TYPE_AUTOMATIC) {
555 		struct g_concat_metadata md;
556 
557 		/* Re-read metadata. */
558 		error = g_concat_read_metadata(cp, &md);
559 		if (error != 0)
560 			goto fail;
561 
562 		if (strcmp(md.md_magic, G_CONCAT_MAGIC) != 0 ||
563 		    strcmp(md.md_name, sc->sc_name) != 0 ||
564 		    md.md_id != sc->sc_id) {
565 			G_CONCAT_DEBUG(0, "Metadata on %s changed.", pp->name);
566 			goto fail;
567 		}
568 	}
569 
570 	cp->private = disk;
571 	disk->d_consumer = cp;
572 	disk->d_softc = sc;
573 	disk->d_start = 0;	/* not yet */
574 	disk->d_end = 0;	/* not yet */
575 	disk->d_removed = 0;
576 
577 	G_CONCAT_DEBUG(0, "Disk %s attached to %s.", pp->name, sc->sc_name);
578 
579 	g_concat_check_and_run(sc);
580 
581 	return (0);
582 fail:
583 	if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0))
584 		g_access(cp, -fcp->acr, -fcp->acw, -fcp->ace);
585 	g_detach(cp);
586 	g_destroy_consumer(cp);
587 	return (error);
588 }
589 
590 static struct g_geom *
591 g_concat_create(struct g_class *mp, const struct g_concat_metadata *md,
592     u_int type)
593 {
594 	struct g_concat_softc *sc;
595 	struct g_geom *gp;
596 	u_int no;
597 
598 	G_CONCAT_DEBUG(1, "Creating device %s (id=%u).", md->md_name,
599 	    md->md_id);
600 
601 	/* One disks is minimum. */
602 	if (md->md_all < 1)
603 		return (NULL);
604 
605 	/* Check for duplicate unit */
606 	LIST_FOREACH(gp, &mp->geom, geom) {
607 		sc = gp->softc;
608 		if (sc != NULL && strcmp(sc->sc_name, md->md_name) == 0) {
609 			G_CONCAT_DEBUG(0, "Device %s already configured.",
610 			    gp->name);
611 			return (NULL);
612 		}
613 	}
614 	gp = g_new_geomf(mp, "%s", md->md_name);
615 	sc = malloc(sizeof(*sc), M_CONCAT, M_WAITOK | M_ZERO);
616 	gp->start = g_concat_start;
617 	gp->spoiled = g_concat_orphan;
618 	gp->orphan = g_concat_orphan;
619 	gp->access = g_concat_access;
620 	gp->dumpconf = g_concat_dumpconf;
621 
622 	sc->sc_id = md->md_id;
623 	sc->sc_ndisks = md->md_all;
624 	sc->sc_disks = malloc(sizeof(struct g_concat_disk) * sc->sc_ndisks,
625 	    M_CONCAT, M_WAITOK | M_ZERO);
626 	for (no = 0; no < sc->sc_ndisks; no++)
627 		sc->sc_disks[no].d_consumer = NULL;
628 	sc->sc_type = type;
629 	mtx_init(&sc->sc_lock, "gconcat lock", NULL, MTX_DEF);
630 
631 	gp->softc = sc;
632 	sc->sc_geom = gp;
633 	sc->sc_provider = NULL;
634 
635 	G_CONCAT_DEBUG(0, "Device %s created (id=%u).", sc->sc_name, sc->sc_id);
636 
637 	return (gp);
638 }
639 
640 static int
641 g_concat_destroy(struct g_concat_softc *sc, boolean_t force)
642 {
643 	struct g_provider *pp;
644 	struct g_consumer *cp, *cp1;
645 	struct g_geom *gp;
646 
647 	g_topology_assert();
648 
649 	if (sc == NULL)
650 		return (ENXIO);
651 
652 	pp = sc->sc_provider;
653 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
654 		if (force) {
655 			G_CONCAT_DEBUG(0, "Device %s is still open, so it "
656 			    "can't be definitely removed.", pp->name);
657 		} else {
658 			G_CONCAT_DEBUG(1,
659 			    "Device %s is still open (r%dw%de%d).", pp->name,
660 			    pp->acr, pp->acw, pp->ace);
661 			return (EBUSY);
662 		}
663 	}
664 
665 	gp = sc->sc_geom;
666 	LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp1) {
667 		g_concat_remove_disk(cp->private);
668 		if (cp1 == NULL)
669 			return (0);	/* Recursion happened. */
670 	}
671 	if (!LIST_EMPTY(&gp->consumer))
672 		return (EINPROGRESS);
673 
674 	gp->softc = NULL;
675 	KASSERT(sc->sc_provider == NULL, ("Provider still exists? (device=%s)",
676 	    gp->name));
677 	free(sc->sc_disks, M_CONCAT);
678 	mtx_destroy(&sc->sc_lock);
679 	free(sc, M_CONCAT);
680 
681 	G_CONCAT_DEBUG(0, "Device %s destroyed.", gp->name);
682 	g_wither_geom(gp, ENXIO);
683 	return (0);
684 }
685 
686 static int
687 g_concat_destroy_geom(struct gctl_req *req __unused,
688     struct g_class *mp __unused, struct g_geom *gp)
689 {
690 	struct g_concat_softc *sc;
691 
692 	sc = gp->softc;
693 	return (g_concat_destroy(sc, 0));
694 }
695 
696 static struct g_geom *
697 g_concat_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
698 {
699 	struct g_concat_metadata md;
700 	struct g_concat_softc *sc;
701 	struct g_consumer *cp;
702 	struct g_geom *gp;
703 	int error;
704 
705 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
706 	g_topology_assert();
707 
708 	/* Skip providers that are already open for writing. */
709 	if (pp->acw > 0)
710 		return (NULL);
711 
712 	G_CONCAT_DEBUG(3, "Tasting %s.", pp->name);
713 
714 	gp = g_new_geomf(mp, "concat:taste");
715 	gp->start = g_concat_start;
716 	gp->access = g_concat_access;
717 	gp->orphan = g_concat_orphan;
718 	cp = g_new_consumer(gp);
719 	g_attach(cp, pp);
720 	error = g_concat_read_metadata(cp, &md);
721 	g_detach(cp);
722 	g_destroy_consumer(cp);
723 	g_destroy_geom(gp);
724 	if (error != 0)
725 		return (NULL);
726 	gp = NULL;
727 
728 	if (strcmp(md.md_magic, G_CONCAT_MAGIC) != 0)
729 		return (NULL);
730 	if (md.md_version > G_CONCAT_VERSION) {
731 		printf("geom_concat.ko module is too old to handle %s.\n",
732 		    pp->name);
733 		return (NULL);
734 	}
735 	/*
736 	 * Backward compatibility:
737 	 */
738 	/* There was no md_provider field in earlier versions of metadata. */
739 	if (md.md_version < 3)
740 		bzero(md.md_provider, sizeof(md.md_provider));
741 	/* There was no md_provsize field in earlier versions of metadata. */
742 	if (md.md_version < 4)
743 		md.md_provsize = pp->mediasize;
744 
745 	if (md.md_provider[0] != '\0' &&
746 	    !g_compare_names(md.md_provider, pp->name))
747 		return (NULL);
748 	if (md.md_provsize != pp->mediasize)
749 		return (NULL);
750 
751 	/*
752 	 * Let's check if device already exists.
753 	 */
754 	sc = NULL;
755 	LIST_FOREACH(gp, &mp->geom, geom) {
756 		sc = gp->softc;
757 		if (sc == NULL)
758 			continue;
759 		if (sc->sc_type != G_CONCAT_TYPE_AUTOMATIC)
760 			continue;
761 		if (strcmp(md.md_name, sc->sc_name) != 0)
762 			continue;
763 		if (md.md_id != sc->sc_id)
764 			continue;
765 		break;
766 	}
767 	if (gp != NULL) {
768 		G_CONCAT_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
769 		error = g_concat_add_disk(sc, pp, md.md_no);
770 		if (error != 0) {
771 			G_CONCAT_DEBUG(0,
772 			    "Cannot add disk %s to %s (error=%d).", pp->name,
773 			    gp->name, error);
774 			return (NULL);
775 		}
776 	} else {
777 		gp = g_concat_create(mp, &md, G_CONCAT_TYPE_AUTOMATIC);
778 		if (gp == NULL) {
779 			G_CONCAT_DEBUG(0, "Cannot create device %s.",
780 			    md.md_name);
781 			return (NULL);
782 		}
783 		sc = gp->softc;
784 		G_CONCAT_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
785 		error = g_concat_add_disk(sc, pp, md.md_no);
786 		if (error != 0) {
787 			G_CONCAT_DEBUG(0,
788 			    "Cannot add disk %s to %s (error=%d).", pp->name,
789 			    gp->name, error);
790 			g_concat_destroy(sc, 1);
791 			return (NULL);
792 		}
793 	}
794 
795 	return (gp);
796 }
797 
798 static void
799 g_concat_ctl_create(struct gctl_req *req, struct g_class *mp)
800 {
801 	u_int attached, no;
802 	struct g_concat_metadata md;
803 	struct g_provider *pp;
804 	struct g_concat_softc *sc;
805 	struct g_geom *gp;
806 	struct sbuf *sb;
807 	const char *name;
808 	char param[16];
809 	int *nargs;
810 
811 	g_topology_assert();
812 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
813 	if (nargs == NULL) {
814 		gctl_error(req, "No '%s' argument.", "nargs");
815 		return;
816 	}
817 	if (*nargs < 2) {
818 		gctl_error(req, "Too few arguments.");
819 		return;
820 	}
821 
822 	strlcpy(md.md_magic, G_CONCAT_MAGIC, sizeof(md.md_magic));
823 	md.md_version = G_CONCAT_VERSION;
824 	name = gctl_get_asciiparam(req, "arg0");
825 	if (name == NULL) {
826 		gctl_error(req, "No 'arg%u' argument.", 0);
827 		return;
828 	}
829 	strlcpy(md.md_name, name, sizeof(md.md_name));
830 	md.md_id = arc4random();
831 	md.md_no = 0;
832 	md.md_all = *nargs - 1;
833 	bzero(md.md_provider, sizeof(md.md_provider));
834 	/* This field is not important here. */
835 	md.md_provsize = 0;
836 
837 	/* Check all providers are valid */
838 	for (no = 1; no < *nargs; no++) {
839 		snprintf(param, sizeof(param), "arg%u", no);
840 		name = gctl_get_asciiparam(req, param);
841 		if (name == NULL) {
842 			gctl_error(req, "No 'arg%u' argument.", no);
843 			return;
844 		}
845 		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
846 			name += strlen("/dev/");
847 		pp = g_provider_by_name(name);
848 		if (pp == NULL) {
849 			G_CONCAT_DEBUG(1, "Disk %s is invalid.", name);
850 			gctl_error(req, "Disk %s is invalid.", name);
851 			return;
852 		}
853 	}
854 
855 	gp = g_concat_create(mp, &md, G_CONCAT_TYPE_MANUAL);
856 	if (gp == NULL) {
857 		gctl_error(req, "Can't configure %s.", md.md_name);
858 		return;
859 	}
860 
861 	sc = gp->softc;
862 	sb = sbuf_new_auto();
863 	sbuf_printf(sb, "Can't attach disk(s) to %s:", gp->name);
864 	for (attached = 0, no = 1; no < *nargs; no++) {
865 		snprintf(param, sizeof(param), "arg%u", no);
866 		name = gctl_get_asciiparam(req, param);
867 		if (name == NULL) {
868 			gctl_error(req, "No 'arg%d' argument.", no);
869 			return;
870 		}
871 		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
872 			name += strlen("/dev/");
873 		pp = g_provider_by_name(name);
874 		KASSERT(pp != NULL, ("Provider %s disappear?!", name));
875 		if (g_concat_add_disk(sc, pp, no - 1) != 0) {
876 			G_CONCAT_DEBUG(1, "Disk %u (%s) not attached to %s.",
877 			    no, pp->name, gp->name);
878 			sbuf_printf(sb, " %s", pp->name);
879 			continue;
880 		}
881 		attached++;
882 	}
883 	sbuf_finish(sb);
884 	if (md.md_all != attached) {
885 		g_concat_destroy(gp->softc, 1);
886 		gctl_error(req, "%s", sbuf_data(sb));
887 	}
888 	sbuf_delete(sb);
889 }
890 
891 static struct g_concat_softc *
892 g_concat_find_device(struct g_class *mp, const char *name)
893 {
894 	struct g_concat_softc *sc;
895 	struct g_geom *gp;
896 
897 	LIST_FOREACH(gp, &mp->geom, geom) {
898 		sc = gp->softc;
899 		if (sc == NULL)
900 			continue;
901 		if (strcmp(sc->sc_name, name) == 0)
902 			return (sc);
903 	}
904 	return (NULL);
905 }
906 
907 static void
908 g_concat_ctl_destroy(struct gctl_req *req, struct g_class *mp)
909 {
910 	struct g_concat_softc *sc;
911 	int *force, *nargs, error;
912 	const char *name;
913 	char param[16];
914 	u_int i;
915 
916 	g_topology_assert();
917 
918 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
919 	if (nargs == NULL) {
920 		gctl_error(req, "No '%s' argument.", "nargs");
921 		return;
922 	}
923 	if (*nargs <= 0) {
924 		gctl_error(req, "Missing device(s).");
925 		return;
926 	}
927 	force = gctl_get_paraml(req, "force", sizeof(*force));
928 	if (force == NULL) {
929 		gctl_error(req, "No '%s' argument.", "force");
930 		return;
931 	}
932 
933 	for (i = 0; i < (u_int)*nargs; i++) {
934 		snprintf(param, sizeof(param), "arg%u", i);
935 		name = gctl_get_asciiparam(req, param);
936 		if (name == NULL) {
937 			gctl_error(req, "No 'arg%u' argument.", i);
938 			return;
939 		}
940 		sc = g_concat_find_device(mp, name);
941 		if (sc == NULL) {
942 			gctl_error(req, "No such device: %s.", name);
943 			return;
944 		}
945 		error = g_concat_destroy(sc, *force);
946 		if (error != 0) {
947 			gctl_error(req, "Cannot destroy device %s (error=%d).",
948 			    sc->sc_name, error);
949 			return;
950 		}
951 	}
952 }
953 
954 static void
955 g_concat_config(struct gctl_req *req, struct g_class *mp, const char *verb)
956 {
957 	uint32_t *version;
958 
959 	g_topology_assert();
960 
961 	version = gctl_get_paraml(req, "version", sizeof(*version));
962 	if (version == NULL) {
963 		gctl_error(req, "No '%s' argument.", "version");
964 		return;
965 	}
966 	if (*version != G_CONCAT_VERSION) {
967 		gctl_error(req, "Userland and kernel parts are out of sync.");
968 		return;
969 	}
970 
971 	if (strcmp(verb, "create") == 0) {
972 		g_concat_ctl_create(req, mp);
973 		return;
974 	} else if (strcmp(verb, "destroy") == 0 ||
975 	    strcmp(verb, "stop") == 0) {
976 		g_concat_ctl_destroy(req, mp);
977 		return;
978 	}
979 	gctl_error(req, "Unknown verb.");
980 }
981 
982 static void
983 g_concat_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
984     struct g_consumer *cp, struct g_provider *pp)
985 {
986 	struct g_concat_softc *sc;
987 
988 	g_topology_assert();
989 	sc = gp->softc;
990 	if (sc == NULL)
991 		return;
992 	if (pp != NULL) {
993 		/* Nothing here. */
994 	} else if (cp != NULL) {
995 		struct g_concat_disk *disk;
996 
997 		disk = cp->private;
998 		if (disk == NULL)
999 			return;
1000 		sbuf_printf(sb, "%s<End>%jd</End>\n", indent,
1001 		    (intmax_t)disk->d_end);
1002 		sbuf_printf(sb, "%s<Start>%jd</Start>\n", indent,
1003 		    (intmax_t)disk->d_start);
1004 	} else {
1005 		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
1006 		sbuf_printf(sb, "%s<Type>", indent);
1007 		switch (sc->sc_type) {
1008 		case G_CONCAT_TYPE_AUTOMATIC:
1009 			sbuf_printf(sb, "AUTOMATIC");
1010 			break;
1011 		case G_CONCAT_TYPE_MANUAL:
1012 			sbuf_printf(sb, "MANUAL");
1013 			break;
1014 		default:
1015 			sbuf_printf(sb, "UNKNOWN");
1016 			break;
1017 		}
1018 		sbuf_printf(sb, "</Type>\n");
1019 		sbuf_printf(sb, "%s<Status>Total=%u, Online=%u</Status>\n",
1020 		    indent, sc->sc_ndisks, g_concat_nvalid(sc));
1021 		sbuf_printf(sb, "%s<State>", indent);
1022 		if (sc->sc_provider != NULL && sc->sc_provider->error == 0)
1023 			sbuf_printf(sb, "UP");
1024 		else
1025 			sbuf_printf(sb, "DOWN");
1026 		sbuf_printf(sb, "</State>\n");
1027 	}
1028 }
1029 
1030 DECLARE_GEOM_CLASS(g_concat_class, g_concat);
1031 MODULE_VERSION(geom_concat, 0);
1032