xref: /freebsd/sys/geom/stripe/g_stripe.c (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
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 <vm/uma.h>
43 #include <geom/geom.h>
44 #include <geom/geom_dbg.h>
45 #include <geom/stripe/g_stripe.h>
46 
47 FEATURE(geom_stripe, "GEOM striping support");
48 
49 static MALLOC_DEFINE(M_STRIPE, "stripe_data", "GEOM_STRIPE Data");
50 
51 static uma_zone_t g_stripe_zone;
52 
53 static int g_stripe_destroy(struct g_stripe_softc *sc, boolean_t force);
54 static int g_stripe_destroy_geom(struct gctl_req *req, struct g_class *mp,
55     struct g_geom *gp);
56 
57 static g_taste_t g_stripe_taste;
58 static g_ctl_req_t g_stripe_config;
59 static g_dumpconf_t g_stripe_dumpconf;
60 static g_init_t g_stripe_init;
61 static g_fini_t g_stripe_fini;
62 
63 struct g_class g_stripe_class = {
64 	.name = G_STRIPE_CLASS_NAME,
65 	.version = G_VERSION,
66 	.ctlreq = g_stripe_config,
67 	.taste = g_stripe_taste,
68 	.destroy_geom = g_stripe_destroy_geom,
69 	.init = g_stripe_init,
70 	.fini = g_stripe_fini
71 };
72 
73 SYSCTL_DECL(_kern_geom);
74 static SYSCTL_NODE(_kern_geom, OID_AUTO, stripe, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
75     "GEOM_STRIPE stuff");
76 static u_int g_stripe_debug = 0;
77 SYSCTL_UINT(_kern_geom_stripe, OID_AUTO, debug, CTLFLAG_RWTUN, &g_stripe_debug, 0,
78     "Debug level");
79 static int g_stripe_fast = 0;
80 SYSCTL_INT(_kern_geom_stripe, OID_AUTO, fast,
81     CTLFLAG_RWTUN, &g_stripe_fast, 0,
82     "Fast, but memory-consuming, mode");
83 static u_long g_stripe_maxmem;
84 SYSCTL_ULONG(_kern_geom_stripe, OID_AUTO, maxmem,
85     CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &g_stripe_maxmem, 0,
86     "Maximum memory that can be allocated in \"fast\" mode (in bytes)");
87 static u_int g_stripe_fast_failed = 0;
88 SYSCTL_UINT(_kern_geom_stripe, OID_AUTO, fast_failed, CTLFLAG_RD,
89     &g_stripe_fast_failed, 0, "How many times \"fast\" mode failed");
90 
91 /*
92  * Greatest Common Divisor.
93  */
94 static u_int
95 gcd(u_int a, u_int b)
96 {
97 	u_int c;
98 
99 	while (b != 0) {
100 		c = a;
101 		a = b;
102 		b = (c % b);
103 	}
104 	return (a);
105 }
106 
107 /*
108  * Least Common Multiple.
109  */
110 static u_int
111 lcm(u_int a, u_int b)
112 {
113 
114 	return ((a * b) / gcd(a, b));
115 }
116 
117 static void
118 g_stripe_init(struct g_class *mp __unused)
119 {
120 
121 	g_stripe_maxmem = maxphys * 100;
122 	TUNABLE_ULONG_FETCH("kern.geom.stripe.maxmem,", &g_stripe_maxmem);
123 	g_stripe_zone = uma_zcreate("g_stripe_zone", maxphys, NULL, NULL,
124 	    NULL, NULL, 0, 0);
125 	g_stripe_maxmem -= g_stripe_maxmem % maxphys;
126 	uma_zone_set_max(g_stripe_zone, g_stripe_maxmem / maxphys);
127 }
128 
129 static void
130 g_stripe_fini(struct g_class *mp __unused)
131 {
132 
133 	uma_zdestroy(g_stripe_zone);
134 }
135 
136 /*
137  * Return the number of valid disks.
138  */
139 static u_int
140 g_stripe_nvalid(struct g_stripe_softc *sc)
141 {
142 	u_int i, no;
143 
144 	no = 0;
145 	for (i = 0; i < sc->sc_ndisks; i++) {
146 		if (sc->sc_disks[i] != NULL)
147 			no++;
148 	}
149 
150 	return (no);
151 }
152 
153 static void
154 g_stripe_remove_disk(struct g_consumer *cp)
155 {
156 	struct g_stripe_softc *sc;
157 
158 	g_topology_assert();
159 	KASSERT(cp != NULL, ("Non-valid disk in %s.", __func__));
160 	sc = (struct g_stripe_softc *)cp->geom->softc;
161 	KASSERT(sc != NULL, ("NULL sc in %s.", __func__));
162 
163 	if (cp->private == NULL) {
164 		G_STRIPE_DEBUG(0, "Disk %s removed from %s.",
165 		    cp->provider->name, sc->sc_name);
166 		cp->private = (void *)(uintptr_t)-1;
167 	}
168 
169 	if (sc->sc_provider != NULL) {
170 		G_STRIPE_DEBUG(0, "Device %s deactivated.",
171 		    sc->sc_provider->name);
172 		g_wither_provider(sc->sc_provider, ENXIO);
173 		sc->sc_provider = NULL;
174 	}
175 
176 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
177 		return;
178 	sc->sc_disks[cp->index] = NULL;
179 	cp->index = 0;
180 	g_detach(cp);
181 	g_destroy_consumer(cp);
182 	/* If there are no valid disks anymore, remove device. */
183 	if (LIST_EMPTY(&sc->sc_geom->consumer))
184 		g_stripe_destroy(sc, 1);
185 }
186 
187 static void
188 g_stripe_orphan(struct g_consumer *cp)
189 {
190 	struct g_stripe_softc *sc;
191 	struct g_geom *gp;
192 
193 	g_topology_assert();
194 	gp = cp->geom;
195 	sc = gp->softc;
196 	if (sc == NULL)
197 		return;
198 
199 	g_stripe_remove_disk(cp);
200 }
201 
202 static int
203 g_stripe_access(struct g_provider *pp, int dr, int dw, int de)
204 {
205 	struct g_consumer *cp1, *cp2, *tmp;
206 	struct g_stripe_softc *sc __diagused;
207 	struct g_geom *gp;
208 	int error;
209 
210 	g_topology_assert();
211 	gp = pp->geom;
212 	sc = gp->softc;
213 	KASSERT(sc != NULL, ("NULL sc in %s.", __func__));
214 
215 	/* On first open, grab an extra "exclusive" bit */
216 	if (pp->acr == 0 && pp->acw == 0 && pp->ace == 0)
217 		de++;
218 	/* ... and let go of it on last close */
219 	if ((pp->acr + dr) == 0 && (pp->acw + dw) == 0 && (pp->ace + de) == 0)
220 		de--;
221 
222 	LIST_FOREACH_SAFE(cp1, &gp->consumer, consumer, tmp) {
223 		error = g_access(cp1, dr, dw, de);
224 		if (error != 0)
225 			goto fail;
226 		if (cp1->acr == 0 && cp1->acw == 0 && cp1->ace == 0 &&
227 		    cp1->private != NULL) {
228 			g_stripe_remove_disk(cp1); /* May destroy geom. */
229 		}
230 	}
231 	return (0);
232 
233 fail:
234 	LIST_FOREACH(cp2, &gp->consumer, consumer) {
235 		if (cp1 == cp2)
236 			break;
237 		g_access(cp2, -dr, -dw, -de);
238 	}
239 	return (error);
240 }
241 
242 static void
243 g_stripe_copy(struct g_stripe_softc *sc, char *src, char *dst, off_t offset,
244     off_t length, int mode)
245 {
246 	off_t stripesize;
247 	size_t len;
248 
249 	stripesize = sc->sc_stripesize;
250 	len = (size_t)(stripesize - (offset & (stripesize - 1)));
251 	do {
252 		bcopy(src, dst, len);
253 		if (mode) {
254 			dst += len + stripesize * (sc->sc_ndisks - 1);
255 			src += len;
256 		} else {
257 			dst += len;
258 			src += len + stripesize * (sc->sc_ndisks - 1);
259 		}
260 		length -= len;
261 		KASSERT(length >= 0,
262 		    ("Length < 0 (stripesize=%ju, offset=%ju, length=%jd).",
263 		    (uintmax_t)stripesize, (uintmax_t)offset, (intmax_t)length));
264 		if (length > stripesize)
265 			len = stripesize;
266 		else
267 			len = length;
268 	} while (length > 0);
269 }
270 
271 static void
272 g_stripe_done(struct bio *bp)
273 {
274 	struct g_stripe_softc *sc;
275 	struct bio *pbp;
276 
277 	pbp = bp->bio_parent;
278 	sc = pbp->bio_to->geom->softc;
279 	if (bp->bio_cmd == BIO_READ && bp->bio_caller1 != NULL) {
280 		g_stripe_copy(sc, bp->bio_data, bp->bio_caller1, bp->bio_offset,
281 		    bp->bio_length, 1);
282 		bp->bio_data = bp->bio_caller1;
283 		bp->bio_caller1 = NULL;
284 	}
285 	mtx_lock(&sc->sc_lock);
286 	if (pbp->bio_error == 0)
287 		pbp->bio_error = bp->bio_error;
288 	pbp->bio_completed += bp->bio_completed;
289 	pbp->bio_inbed++;
290 	if (pbp->bio_children == pbp->bio_inbed) {
291 		mtx_unlock(&sc->sc_lock);
292 		if (pbp->bio_driver1 != NULL)
293 			uma_zfree(g_stripe_zone, pbp->bio_driver1);
294 		if (bp->bio_cmd == BIO_SPEEDUP)
295 			pbp->bio_completed = pbp->bio_length;
296 		g_io_deliver(pbp, pbp->bio_error);
297 	} else
298 		mtx_unlock(&sc->sc_lock);
299 	g_destroy_bio(bp);
300 }
301 
302 static int
303 g_stripe_start_fast(struct bio *bp, u_int no, off_t offset, off_t length)
304 {
305 	TAILQ_HEAD(, bio) queue = TAILQ_HEAD_INITIALIZER(queue);
306 	struct g_stripe_softc *sc;
307 	char *addr, *data = NULL;
308 	struct bio *cbp;
309 	off_t stripesize;
310 	u_int nparts = 0;
311 	int error;
312 
313 	sc = bp->bio_to->geom->softc;
314 
315 	addr = bp->bio_data;
316 	stripesize = sc->sc_stripesize;
317 
318 	cbp = g_clone_bio(bp);
319 	if (cbp == NULL) {
320 		error = ENOMEM;
321 		goto failure;
322 	}
323 	TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
324 	nparts++;
325 	/*
326 	 * Fill in the component buf structure.
327 	 */
328 	cbp->bio_done = g_stripe_done;
329 	cbp->bio_offset = offset;
330 	cbp->bio_data = addr;
331 	cbp->bio_caller1 = NULL;
332 	cbp->bio_length = length;
333 	cbp->bio_caller2 = sc->sc_disks[no];
334 
335 	/* offset -= offset % stripesize; */
336 	offset -= offset & (stripesize - 1);
337 	addr += length;
338 	length = bp->bio_length - length;
339 	for (no++; length > 0; no++, length -= stripesize, addr += stripesize) {
340 		if (no > sc->sc_ndisks - 1) {
341 			no = 0;
342 			offset += stripesize;
343 		}
344 		if (nparts >= sc->sc_ndisks) {
345 			cbp = TAILQ_NEXT(cbp, bio_queue);
346 			if (cbp == NULL)
347 				cbp = TAILQ_FIRST(&queue);
348 			nparts++;
349 			/*
350 			 * Update bio structure.
351 			 */
352 			/*
353 			 * MIN() is in case when
354 			 * (bp->bio_length % sc->sc_stripesize) != 0.
355 			 */
356 			cbp->bio_length += MIN(stripesize, length);
357 			if (cbp->bio_caller1 == NULL) {
358 				cbp->bio_caller1 = cbp->bio_data;
359 				cbp->bio_data = NULL;
360 				if (data == NULL) {
361 					data = uma_zalloc(g_stripe_zone,
362 					    M_NOWAIT);
363 					if (data == NULL) {
364 						error = ENOMEM;
365 						goto failure;
366 					}
367 				}
368 			}
369 		} else {
370 			cbp = g_clone_bio(bp);
371 			if (cbp == NULL) {
372 				error = ENOMEM;
373 				goto failure;
374 			}
375 			TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
376 			nparts++;
377 			/*
378 			 * Fill in the component buf structure.
379 			 */
380 			cbp->bio_done = g_stripe_done;
381 			cbp->bio_offset = offset;
382 			cbp->bio_data = addr;
383 			cbp->bio_caller1 = NULL;
384 			/*
385 			 * MIN() is in case when
386 			 * (bp->bio_length % sc->sc_stripesize) != 0.
387 			 */
388 			cbp->bio_length = MIN(stripesize, length);
389 			cbp->bio_caller2 = sc->sc_disks[no];
390 		}
391 	}
392 	if (data != NULL)
393 		bp->bio_driver1 = data;
394 	/*
395 	 * Fire off all allocated requests!
396 	 */
397 	while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
398 		struct g_consumer *cp;
399 
400 		TAILQ_REMOVE(&queue, cbp, bio_queue);
401 		cp = cbp->bio_caller2;
402 		cbp->bio_caller2 = NULL;
403 		cbp->bio_to = cp->provider;
404 		if (cbp->bio_caller1 != NULL) {
405 			cbp->bio_data = data;
406 			if (bp->bio_cmd == BIO_WRITE) {
407 				g_stripe_copy(sc, cbp->bio_caller1, data,
408 				    cbp->bio_offset, cbp->bio_length, 0);
409 			}
410 			data += cbp->bio_length;
411 		}
412 		G_STRIPE_LOGREQ(cbp, "Sending request.");
413 		g_io_request(cbp, cp);
414 	}
415 	return (0);
416 failure:
417 	if (data != NULL)
418 		uma_zfree(g_stripe_zone, data);
419 	while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
420 		TAILQ_REMOVE(&queue, cbp, bio_queue);
421 		if (cbp->bio_caller1 != NULL) {
422 			cbp->bio_data = cbp->bio_caller1;
423 			cbp->bio_caller1 = NULL;
424 		}
425 		bp->bio_children--;
426 		g_destroy_bio(cbp);
427 	}
428 	return (error);
429 }
430 
431 static int
432 g_stripe_start_economic(struct bio *bp, u_int no, off_t offset, off_t length)
433 {
434 	TAILQ_HEAD(, bio) queue = TAILQ_HEAD_INITIALIZER(queue);
435 	struct g_stripe_softc *sc;
436 	off_t stripesize;
437 	struct bio *cbp;
438 	char *addr;
439 	int error;
440 
441 	sc = bp->bio_to->geom->softc;
442 
443 	stripesize = sc->sc_stripesize;
444 
445 	cbp = g_clone_bio(bp);
446 	if (cbp == NULL) {
447 		error = ENOMEM;
448 		goto failure;
449 	}
450 	TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
451 	/*
452 	 * Fill in the component buf structure.
453 	 */
454 	if (bp->bio_length == length)
455 		cbp->bio_done = g_std_done;	/* Optimized lockless case. */
456 	else
457 		cbp->bio_done = g_stripe_done;
458 	cbp->bio_offset = offset;
459 	cbp->bio_length = length;
460 	if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
461 		bp->bio_ma_n = round_page(bp->bio_ma_offset +
462 		    bp->bio_length) / PAGE_SIZE;
463 		addr = NULL;
464 	} else
465 		addr = bp->bio_data;
466 	cbp->bio_caller2 = sc->sc_disks[no];
467 
468 	/* offset -= offset % stripesize; */
469 	offset -= offset & (stripesize - 1);
470 	if (bp->bio_cmd != BIO_DELETE)
471 		addr += length;
472 	length = bp->bio_length - length;
473 	for (no++; length > 0; no++, length -= stripesize) {
474 		if (no > sc->sc_ndisks - 1) {
475 			no = 0;
476 			offset += stripesize;
477 		}
478 		cbp = g_clone_bio(bp);
479 		if (cbp == NULL) {
480 			error = ENOMEM;
481 			goto failure;
482 		}
483 		TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
484 
485 		/*
486 		 * Fill in the component buf structure.
487 		 */
488 		cbp->bio_done = g_stripe_done;
489 		cbp->bio_offset = offset;
490 		/*
491 		 * MIN() is in case when
492 		 * (bp->bio_length % sc->sc_stripesize) != 0.
493 		 */
494 		cbp->bio_length = MIN(stripesize, length);
495 		if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
496 			cbp->bio_ma_offset += (uintptr_t)addr;
497 			cbp->bio_ma += cbp->bio_ma_offset / PAGE_SIZE;
498 			cbp->bio_ma_offset %= PAGE_SIZE;
499 			cbp->bio_ma_n = round_page(cbp->bio_ma_offset +
500 			    cbp->bio_length) / PAGE_SIZE;
501 		} else
502 			cbp->bio_data = addr;
503 
504 		cbp->bio_caller2 = sc->sc_disks[no];
505 
506 		if (bp->bio_cmd != BIO_DELETE)
507 			addr += stripesize;
508 	}
509 	/*
510 	 * Fire off all allocated requests!
511 	 */
512 	while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
513 		struct g_consumer *cp;
514 
515 		TAILQ_REMOVE(&queue, cbp, bio_queue);
516 		cp = cbp->bio_caller2;
517 		cbp->bio_caller2 = NULL;
518 		cbp->bio_to = cp->provider;
519 		G_STRIPE_LOGREQ(cbp, "Sending request.");
520 		g_io_request(cbp, cp);
521 	}
522 	return (0);
523 failure:
524 	while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
525 		TAILQ_REMOVE(&queue, cbp, bio_queue);
526 		bp->bio_children--;
527 		g_destroy_bio(cbp);
528 	}
529 	return (error);
530 }
531 
532 static void
533 g_stripe_pushdown(struct g_stripe_softc *sc, struct bio *bp)
534 {
535 	struct bio_queue_head queue;
536 	struct g_consumer *cp;
537 	struct bio *cbp;
538 	u_int no;
539 
540 	bioq_init(&queue);
541 	for (no = 0; no < sc->sc_ndisks; no++) {
542 		cbp = g_clone_bio(bp);
543 		if (cbp == NULL) {
544 			for (cbp = bioq_first(&queue); cbp != NULL;
545 			    cbp = bioq_first(&queue)) {
546 				bioq_remove(&queue, cbp);
547 				g_destroy_bio(cbp);
548 			}
549 			if (bp->bio_error == 0)
550 				bp->bio_error = ENOMEM;
551 			g_io_deliver(bp, bp->bio_error);
552 			return;
553 		}
554 		bioq_insert_tail(&queue, cbp);
555 		cbp->bio_done = g_stripe_done;
556 		cbp->bio_caller2 = sc->sc_disks[no];
557 		cbp->bio_to = sc->sc_disks[no]->provider;
558 	}
559 	for (cbp = bioq_first(&queue); cbp != NULL; cbp = bioq_first(&queue)) {
560 		bioq_remove(&queue, cbp);
561 		G_STRIPE_LOGREQ(cbp, "Sending request.");
562 		cp = cbp->bio_caller2;
563 		cbp->bio_caller2 = NULL;
564 		g_io_request(cbp, cp);
565 	}
566 }
567 
568 static void
569 g_stripe_start(struct bio *bp)
570 {
571 	off_t offset, start, length, nstripe, stripesize;
572 	struct g_stripe_softc *sc;
573 	u_int no;
574 	int error, fast = 0;
575 
576 	sc = bp->bio_to->geom->softc;
577 	/*
578 	 * If sc == NULL, provider's error should be set and g_stripe_start()
579 	 * should not be called at all.
580 	 */
581 	KASSERT(sc != NULL,
582 	    ("Provider's error should be set (error=%d)(device=%s).",
583 	    bp->bio_to->error, bp->bio_to->name));
584 
585 	G_STRIPE_LOGREQ(bp, "Request received.");
586 
587 	switch (bp->bio_cmd) {
588 	case BIO_READ:
589 	case BIO_WRITE:
590 	case BIO_DELETE:
591 		break;
592 	case BIO_SPEEDUP:
593 	case BIO_FLUSH:
594 		g_stripe_pushdown(sc, bp);
595 		return;
596 	case BIO_GETATTR:
597 		/* To which provider it should be delivered? */
598 	default:
599 		g_io_deliver(bp, EOPNOTSUPP);
600 		return;
601 	}
602 
603 	stripesize = sc->sc_stripesize;
604 
605 	/*
606 	 * Calculations are quite messy, but fast I hope.
607 	 */
608 
609 	/* Stripe number. */
610 	/* nstripe = bp->bio_offset / stripesize; */
611 	nstripe = bp->bio_offset >> (off_t)sc->sc_stripebits;
612 	/* Disk number. */
613 	no = nstripe % sc->sc_ndisks;
614 	/* Start position in stripe. */
615 	/* start = bp->bio_offset % stripesize; */
616 	start = bp->bio_offset & (stripesize - 1);
617 	/* Start position in disk. */
618 	/* offset = (nstripe / sc->sc_ndisks) * stripesize + start; */
619 	offset = ((nstripe / sc->sc_ndisks) << sc->sc_stripebits) + start;
620 	/* Length of data to operate. */
621 	length = MIN(bp->bio_length, stripesize - start);
622 
623 	/*
624 	 * Do use "fast" mode when:
625 	 * 1. "Fast" mode is ON.
626 	 * and
627 	 * 2. Request size is less than or equal to maxphys,
628 	 *    which should always be true.
629 	 * and
630 	 * 3. Request size is bigger than stripesize * ndisks. If it isn't,
631 	 *    there will be no need to send more than one I/O request to
632 	 *    a provider, so there is nothing to optmize.
633 	 * and
634 	 * 4. Request is not unmapped.
635 	 * and
636 	 * 5. It is not a BIO_DELETE.
637 	 */
638 	if (g_stripe_fast && bp->bio_length <= maxphys &&
639 	    bp->bio_length >= stripesize * sc->sc_ndisks &&
640 	    (bp->bio_flags & BIO_UNMAPPED) == 0 &&
641 	    bp->bio_cmd != BIO_DELETE) {
642 		fast = 1;
643 	}
644 	error = 0;
645 	if (fast) {
646 		error = g_stripe_start_fast(bp, no, offset, length);
647 		if (error != 0)
648 			g_stripe_fast_failed++;
649 	}
650 	/*
651 	 * Do use "economic" when:
652 	 * 1. "Economic" mode is ON.
653 	 * or
654 	 * 2. "Fast" mode failed. It can only fail if there is no memory.
655 	 */
656 	if (!fast || error != 0)
657 		error = g_stripe_start_economic(bp, no, offset, length);
658 	if (error != 0) {
659 		if (bp->bio_error == 0)
660 			bp->bio_error = error;
661 		g_io_deliver(bp, bp->bio_error);
662 	}
663 }
664 
665 static void
666 g_stripe_check_and_run(struct g_stripe_softc *sc)
667 {
668 	struct g_provider *dp;
669 	off_t mediasize, ms;
670 	u_int no, sectorsize = 0;
671 
672 	g_topology_assert();
673 	if (g_stripe_nvalid(sc) != sc->sc_ndisks)
674 		return;
675 
676 	sc->sc_provider = g_new_providerf(sc->sc_geom, "stripe/%s",
677 	    sc->sc_name);
678 	sc->sc_provider->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE;
679 	if (g_stripe_fast == 0)
680 		sc->sc_provider->flags |= G_PF_ACCEPT_UNMAPPED;
681 	/*
682 	 * Find the smallest disk.
683 	 */
684 	mediasize = sc->sc_disks[0]->provider->mediasize;
685 	if (sc->sc_type == G_STRIPE_TYPE_AUTOMATIC)
686 		mediasize -= sc->sc_disks[0]->provider->sectorsize;
687 	mediasize -= mediasize % sc->sc_stripesize;
688 	sectorsize = sc->sc_disks[0]->provider->sectorsize;
689 	for (no = 1; no < sc->sc_ndisks; no++) {
690 		dp = sc->sc_disks[no]->provider;
691 		ms = dp->mediasize;
692 		if (sc->sc_type == G_STRIPE_TYPE_AUTOMATIC)
693 			ms -= dp->sectorsize;
694 		ms -= ms % sc->sc_stripesize;
695 		if (ms < mediasize)
696 			mediasize = ms;
697 		sectorsize = lcm(sectorsize, dp->sectorsize);
698 
699 		/* A provider underneath us doesn't support unmapped */
700 		if ((dp->flags & G_PF_ACCEPT_UNMAPPED) == 0) {
701 			G_STRIPE_DEBUG(1, "Cancelling unmapped "
702 			    "because of %s.", dp->name);
703 			sc->sc_provider->flags &= ~G_PF_ACCEPT_UNMAPPED;
704 		}
705 	}
706 	sc->sc_provider->sectorsize = sectorsize;
707 	sc->sc_provider->mediasize = mediasize * sc->sc_ndisks;
708 	sc->sc_provider->stripesize = sc->sc_stripesize;
709 	sc->sc_provider->stripeoffset = 0;
710 	g_error_provider(sc->sc_provider, 0);
711 
712 	G_STRIPE_DEBUG(0, "Device %s activated.", sc->sc_provider->name);
713 }
714 
715 static int
716 g_stripe_read_metadata(struct g_consumer *cp, struct g_stripe_metadata *md)
717 {
718 	struct g_provider *pp;
719 	u_char *buf;
720 	int error;
721 
722 	g_topology_assert();
723 
724 	error = g_access(cp, 1, 0, 0);
725 	if (error != 0)
726 		return (error);
727 	pp = cp->provider;
728 	g_topology_unlock();
729 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
730 	    &error);
731 	g_topology_lock();
732 	g_access(cp, -1, 0, 0);
733 	if (buf == NULL)
734 		return (error);
735 
736 	/* Decode metadata. */
737 	stripe_metadata_decode(buf, md);
738 	g_free(buf);
739 
740 	return (0);
741 }
742 
743 /*
744  * Add disk to given device.
745  */
746 static int
747 g_stripe_add_disk(struct g_stripe_softc *sc, struct g_provider *pp, u_int no)
748 {
749 	struct g_consumer *cp, *fcp;
750 	struct g_geom *gp;
751 	int error;
752 
753 	g_topology_assert();
754 	/* Metadata corrupted? */
755 	if (no >= sc->sc_ndisks)
756 		return (EINVAL);
757 
758 	/* Check if disk is not already attached. */
759 	if (sc->sc_disks[no] != NULL)
760 		return (EEXIST);
761 
762 	gp = sc->sc_geom;
763 	fcp = LIST_FIRST(&gp->consumer);
764 
765 	cp = g_new_consumer(gp);
766 	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
767 	cp->private = NULL;
768 	cp->index = no;
769 	error = g_attach(cp, pp);
770 	if (error != 0) {
771 		g_destroy_consumer(cp);
772 		return (error);
773 	}
774 
775 	if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0)) {
776 		error = g_access(cp, fcp->acr, fcp->acw, fcp->ace);
777 		if (error != 0) {
778 			g_detach(cp);
779 			g_destroy_consumer(cp);
780 			return (error);
781 		}
782 	}
783 	if (sc->sc_type == G_STRIPE_TYPE_AUTOMATIC) {
784 		struct g_stripe_metadata md;
785 
786 		/* Reread metadata. */
787 		error = g_stripe_read_metadata(cp, &md);
788 		if (error != 0)
789 			goto fail;
790 
791 		if (strcmp(md.md_magic, G_STRIPE_MAGIC) != 0 ||
792 		    strcmp(md.md_name, sc->sc_name) != 0 ||
793 		    md.md_id != sc->sc_id) {
794 			G_STRIPE_DEBUG(0, "Metadata on %s changed.", pp->name);
795 			goto fail;
796 		}
797 	}
798 
799 	sc->sc_disks[no] = cp;
800 	G_STRIPE_DEBUG(0, "Disk %s attached to %s.", pp->name, sc->sc_name);
801 	g_stripe_check_and_run(sc);
802 
803 	return (0);
804 fail:
805 	if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0))
806 		g_access(cp, -fcp->acr, -fcp->acw, -fcp->ace);
807 	g_detach(cp);
808 	g_destroy_consumer(cp);
809 	return (error);
810 }
811 
812 static struct g_geom *
813 g_stripe_create(struct g_class *mp, const struct g_stripe_metadata *md,
814     u_int type)
815 {
816 	struct g_stripe_softc *sc;
817 	struct g_geom *gp;
818 	u_int no;
819 
820 	g_topology_assert();
821 	G_STRIPE_DEBUG(1, "Creating device %s (id=%u).", md->md_name,
822 	    md->md_id);
823 
824 	/* Two disks is minimum. */
825 	if (md->md_all < 2) {
826 		G_STRIPE_DEBUG(0, "Too few disks defined for %s.", md->md_name);
827 		return (NULL);
828 	}
829 #if 0
830 	/* Stripe size have to be grater than or equal to sector size. */
831 	if (md->md_stripesize < sectorsize) {
832 		G_STRIPE_DEBUG(0, "Invalid stripe size for %s.", md->md_name);
833 		return (NULL);
834 	}
835 #endif
836 	/* Stripe size have to be power of 2. */
837 	if (!powerof2(md->md_stripesize)) {
838 		G_STRIPE_DEBUG(0, "Invalid stripe size for %s.", md->md_name);
839 		return (NULL);
840 	}
841 
842 	/* Check for duplicate unit */
843 	LIST_FOREACH(gp, &mp->geom, geom) {
844 		sc = gp->softc;
845 		if (sc != NULL && strcmp(sc->sc_name, md->md_name) == 0) {
846 			G_STRIPE_DEBUG(0, "Device %s already configured.",
847 			    sc->sc_name);
848 			return (NULL);
849 		}
850 	}
851 	gp = g_new_geomf(mp, "%s", md->md_name);
852 	sc = malloc(sizeof(*sc), M_STRIPE, M_WAITOK | M_ZERO);
853 	gp->start = g_stripe_start;
854 	gp->spoiled = g_stripe_orphan;
855 	gp->orphan = g_stripe_orphan;
856 	gp->access = g_stripe_access;
857 	gp->dumpconf = g_stripe_dumpconf;
858 
859 	sc->sc_id = md->md_id;
860 	sc->sc_stripesize = md->md_stripesize;
861 	sc->sc_stripebits = bitcount32(sc->sc_stripesize - 1);
862 	sc->sc_ndisks = md->md_all;
863 	sc->sc_disks = malloc(sizeof(struct g_consumer *) * sc->sc_ndisks,
864 	    M_STRIPE, M_WAITOK | M_ZERO);
865 	for (no = 0; no < sc->sc_ndisks; no++)
866 		sc->sc_disks[no] = NULL;
867 	sc->sc_type = type;
868 	mtx_init(&sc->sc_lock, "gstripe lock", NULL, MTX_DEF);
869 
870 	gp->softc = sc;
871 	sc->sc_geom = gp;
872 	sc->sc_provider = NULL;
873 
874 	G_STRIPE_DEBUG(0, "Device %s created (id=%u).", sc->sc_name, sc->sc_id);
875 
876 	return (gp);
877 }
878 
879 static int
880 g_stripe_destroy(struct g_stripe_softc *sc, boolean_t force)
881 {
882 	struct g_provider *pp;
883 	struct g_consumer *cp, *cp1;
884 	struct g_geom *gp;
885 
886 	g_topology_assert();
887 
888 	if (sc == NULL)
889 		return (ENXIO);
890 
891 	pp = sc->sc_provider;
892 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
893 		if (force) {
894 			G_STRIPE_DEBUG(0, "Device %s is still open, so it "
895 			    "can't be definitely removed.", pp->name);
896 		} else {
897 			G_STRIPE_DEBUG(1,
898 			    "Device %s is still open (r%dw%de%d).", pp->name,
899 			    pp->acr, pp->acw, pp->ace);
900 			return (EBUSY);
901 		}
902 	}
903 
904 	gp = sc->sc_geom;
905 	LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp1) {
906 		g_stripe_remove_disk(cp);
907 		if (cp1 == NULL)
908 			return (0);	/* Recursion happened. */
909 	}
910 	if (!LIST_EMPTY(&gp->consumer))
911 		return (EINPROGRESS);
912 
913 	gp->softc = NULL;
914 	KASSERT(sc->sc_provider == NULL, ("Provider still exists? (device=%s)",
915 	    gp->name));
916 	free(sc->sc_disks, M_STRIPE);
917 	mtx_destroy(&sc->sc_lock);
918 	free(sc, M_STRIPE);
919 	G_STRIPE_DEBUG(0, "Device %s destroyed.", gp->name);
920 	g_wither_geom(gp, ENXIO);
921 	return (0);
922 }
923 
924 static int
925 g_stripe_destroy_geom(struct gctl_req *req __unused,
926     struct g_class *mp __unused, struct g_geom *gp)
927 {
928 	struct g_stripe_softc *sc;
929 
930 	sc = gp->softc;
931 	return (g_stripe_destroy(sc, 0));
932 }
933 
934 static struct g_geom *
935 g_stripe_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
936 {
937 	struct g_stripe_metadata md;
938 	struct g_stripe_softc *sc;
939 	struct g_consumer *cp;
940 	struct g_geom *gp;
941 	int error;
942 
943 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
944 	g_topology_assert();
945 
946 	/* Skip providers that are already open for writing. */
947 	if (pp->acw > 0)
948 		return (NULL);
949 
950 	G_STRIPE_DEBUG(3, "Tasting %s.", pp->name);
951 
952 	gp = g_new_geomf(mp, "stripe:taste");
953 	gp->start = g_stripe_start;
954 	gp->access = g_stripe_access;
955 	gp->orphan = g_stripe_orphan;
956 	cp = g_new_consumer(gp);
957 	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
958 	error = g_attach(cp, pp);
959 	if (error == 0) {
960 		error = g_stripe_read_metadata(cp, &md);
961 		g_detach(cp);
962 	}
963 	g_destroy_consumer(cp);
964 	g_destroy_geom(gp);
965 	if (error != 0)
966 		return (NULL);
967 	gp = NULL;
968 
969 	if (strcmp(md.md_magic, G_STRIPE_MAGIC) != 0)
970 		return (NULL);
971 	if (md.md_version > G_STRIPE_VERSION) {
972 		printf("geom_stripe.ko module is too old to handle %s.\n",
973 		    pp->name);
974 		return (NULL);
975 	}
976 	/*
977 	 * Backward compatibility:
978 	 */
979 	/* There was no md_provider field in earlier versions of metadata. */
980 	if (md.md_version < 2)
981 		bzero(md.md_provider, sizeof(md.md_provider));
982 	/* There was no md_provsize field in earlier versions of metadata. */
983 	if (md.md_version < 3)
984 		md.md_provsize = pp->mediasize;
985 
986 	if (md.md_provider[0] != '\0' &&
987 	    !g_compare_names(md.md_provider, pp->name))
988 		return (NULL);
989 	if (md.md_provsize != pp->mediasize)
990 		return (NULL);
991 
992 	/*
993 	 * Let's check if device already exists.
994 	 */
995 	sc = NULL;
996 	LIST_FOREACH(gp, &mp->geom, geom) {
997 		sc = gp->softc;
998 		if (sc == NULL)
999 			continue;
1000 		if (sc->sc_type != G_STRIPE_TYPE_AUTOMATIC)
1001 			continue;
1002 		if (strcmp(md.md_name, sc->sc_name) != 0)
1003 			continue;
1004 		if (md.md_id != sc->sc_id)
1005 			continue;
1006 		break;
1007 	}
1008 	if (gp != NULL) {
1009 		G_STRIPE_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
1010 		error = g_stripe_add_disk(sc, pp, md.md_no);
1011 		if (error != 0) {
1012 			G_STRIPE_DEBUG(0,
1013 			    "Cannot add disk %s to %s (error=%d).", pp->name,
1014 			    gp->name, error);
1015 			return (NULL);
1016 		}
1017 	} else {
1018 		gp = g_stripe_create(mp, &md, G_STRIPE_TYPE_AUTOMATIC);
1019 		if (gp == NULL) {
1020 			G_STRIPE_DEBUG(0, "Cannot create device %s.",
1021 			    md.md_name);
1022 			return (NULL);
1023 		}
1024 		sc = gp->softc;
1025 		G_STRIPE_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
1026 		error = g_stripe_add_disk(sc, pp, md.md_no);
1027 		if (error != 0) {
1028 			G_STRIPE_DEBUG(0,
1029 			    "Cannot add disk %s to %s (error=%d).", pp->name,
1030 			    gp->name, error);
1031 			g_stripe_destroy(sc, 1);
1032 			return (NULL);
1033 		}
1034 	}
1035 
1036 	return (gp);
1037 }
1038 
1039 static void
1040 g_stripe_ctl_create(struct gctl_req *req, struct g_class *mp)
1041 {
1042 	u_int attached, no;
1043 	struct g_stripe_metadata md;
1044 	struct g_provider *pp;
1045 	struct g_stripe_softc *sc;
1046 	struct g_geom *gp;
1047 	struct sbuf *sb;
1048 	off_t *stripesize;
1049 	const char *name;
1050 	char param[16];
1051 	int *nargs;
1052 
1053 	g_topology_assert();
1054 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
1055 	if (nargs == NULL) {
1056 		gctl_error(req, "No '%s' argument.", "nargs");
1057 		return;
1058 	}
1059 	if (*nargs <= 2) {
1060 		gctl_error(req, "Too few arguments.");
1061 		return;
1062 	}
1063 
1064 	strlcpy(md.md_magic, G_STRIPE_MAGIC, sizeof(md.md_magic));
1065 	md.md_version = G_STRIPE_VERSION;
1066 	name = gctl_get_asciiparam(req, "arg0");
1067 	if (name == NULL) {
1068 		gctl_error(req, "No 'arg%u' argument.", 0);
1069 		return;
1070 	}
1071 	strlcpy(md.md_name, name, sizeof(md.md_name));
1072 	md.md_id = arc4random();
1073 	md.md_no = 0;
1074 	md.md_all = *nargs - 1;
1075 	stripesize = gctl_get_paraml(req, "stripesize", sizeof(*stripesize));
1076 	if (stripesize == NULL) {
1077 		gctl_error(req, "No '%s' argument.", "stripesize");
1078 		return;
1079 	}
1080 	md.md_stripesize = (uint32_t)*stripesize;
1081 	bzero(md.md_provider, sizeof(md.md_provider));
1082 	/* This field is not important here. */
1083 	md.md_provsize = 0;
1084 
1085 	/* Check all providers are valid */
1086 	for (no = 1; no < *nargs; no++) {
1087 		snprintf(param, sizeof(param), "arg%u", no);
1088 		pp = gctl_get_provider(req, param);
1089 		if (pp == NULL)
1090 			return;
1091 	}
1092 
1093 	gp = g_stripe_create(mp, &md, G_STRIPE_TYPE_MANUAL);
1094 	if (gp == NULL) {
1095 		gctl_error(req, "Can't configure %s.", md.md_name);
1096 		return;
1097 	}
1098 
1099 	sc = gp->softc;
1100 	sb = sbuf_new_auto();
1101 	sbuf_printf(sb, "Can't attach disk(s) to %s:", gp->name);
1102 	for (attached = 0, no = 1; no < *nargs; no++) {
1103 		snprintf(param, sizeof(param), "arg%u", no);
1104 		pp  = gctl_get_provider(req, param);
1105 		if (pp == NULL) {
1106 			name = gctl_get_asciiparam(req, param);
1107 			MPASS(name != NULL);
1108 			sbuf_printf(sb, " %s", name);
1109 			continue;
1110 		}
1111 		if (g_stripe_add_disk(sc, pp, no - 1) != 0) {
1112 			G_STRIPE_DEBUG(1, "Disk %u (%s) not attached to %s.",
1113 			    no, pp->name, gp->name);
1114 			sbuf_printf(sb, " %s", pp->name);
1115 			continue;
1116 		}
1117 		attached++;
1118 	}
1119 	sbuf_finish(sb);
1120 	if (md.md_all != attached) {
1121 		g_stripe_destroy(gp->softc, 1);
1122 		gctl_error(req, "%s", sbuf_data(sb));
1123 	}
1124 	sbuf_delete(sb);
1125 }
1126 
1127 static struct g_stripe_softc *
1128 g_stripe_find_device(struct g_class *mp, const char *name)
1129 {
1130 	struct g_stripe_softc *sc;
1131 	struct g_geom *gp;
1132 
1133 	LIST_FOREACH(gp, &mp->geom, geom) {
1134 		sc = gp->softc;
1135 		if (sc == NULL)
1136 			continue;
1137 		if (strcmp(sc->sc_name, name) == 0)
1138 			return (sc);
1139 	}
1140 	return (NULL);
1141 }
1142 
1143 static void
1144 g_stripe_ctl_destroy(struct gctl_req *req, struct g_class *mp)
1145 {
1146 	struct g_stripe_softc *sc;
1147 	int *force, *nargs, error;
1148 	const char *name;
1149 	char param[16];
1150 	u_int i;
1151 
1152 	g_topology_assert();
1153 
1154 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
1155 	if (nargs == NULL) {
1156 		gctl_error(req, "No '%s' argument.", "nargs");
1157 		return;
1158 	}
1159 	if (*nargs <= 0) {
1160 		gctl_error(req, "Missing device(s).");
1161 		return;
1162 	}
1163 	force = gctl_get_paraml(req, "force", sizeof(*force));
1164 	if (force == NULL) {
1165 		gctl_error(req, "No '%s' argument.", "force");
1166 		return;
1167 	}
1168 
1169 	for (i = 0; i < (u_int)*nargs; i++) {
1170 		snprintf(param, sizeof(param), "arg%u", i);
1171 		name = gctl_get_asciiparam(req, param);
1172 		if (name == NULL) {
1173 			gctl_error(req, "No 'arg%u' argument.", i);
1174 			return;
1175 		}
1176 		sc = g_stripe_find_device(mp, name);
1177 		if (sc == NULL) {
1178 			gctl_error(req, "No such device: %s.", name);
1179 			return;
1180 		}
1181 		error = g_stripe_destroy(sc, *force);
1182 		if (error != 0) {
1183 			gctl_error(req, "Cannot destroy device %s (error=%d).",
1184 			    sc->sc_name, error);
1185 			return;
1186 		}
1187 	}
1188 }
1189 
1190 static void
1191 g_stripe_config(struct gctl_req *req, struct g_class *mp, const char *verb)
1192 {
1193 	uint32_t *version;
1194 
1195 	g_topology_assert();
1196 
1197 	version = gctl_get_paraml(req, "version", sizeof(*version));
1198 	if (version == NULL) {
1199 		gctl_error(req, "No '%s' argument.", "version");
1200 		return;
1201 	}
1202 	if (*version != G_STRIPE_VERSION) {
1203 		gctl_error(req, "Userland and kernel parts are out of sync.");
1204 		return;
1205 	}
1206 
1207 	if (strcmp(verb, "create") == 0) {
1208 		g_stripe_ctl_create(req, mp);
1209 		return;
1210 	} else if (strcmp(verb, "destroy") == 0 ||
1211 	    strcmp(verb, "stop") == 0) {
1212 		g_stripe_ctl_destroy(req, mp);
1213 		return;
1214 	}
1215 
1216 	gctl_error(req, "Unknown verb.");
1217 }
1218 
1219 static void
1220 g_stripe_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
1221     struct g_consumer *cp, struct g_provider *pp)
1222 {
1223 	struct g_stripe_softc *sc;
1224 
1225 	sc = gp->softc;
1226 	if (sc == NULL)
1227 		return;
1228 	if (pp != NULL) {
1229 		/* Nothing here. */
1230 	} else if (cp != NULL) {
1231 		sbuf_printf(sb, "%s<Number>%u</Number>\n", indent,
1232 		    (u_int)cp->index);
1233 	} else {
1234 		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
1235 		sbuf_printf(sb, "%s<Stripesize>%ju</Stripesize>\n", indent,
1236 		    (uintmax_t)sc->sc_stripesize);
1237 		sbuf_printf(sb, "%s<Type>", indent);
1238 		switch (sc->sc_type) {
1239 		case G_STRIPE_TYPE_AUTOMATIC:
1240 			sbuf_cat(sb, "AUTOMATIC");
1241 			break;
1242 		case G_STRIPE_TYPE_MANUAL:
1243 			sbuf_cat(sb, "MANUAL");
1244 			break;
1245 		default:
1246 			sbuf_cat(sb, "UNKNOWN");
1247 			break;
1248 		}
1249 		sbuf_cat(sb, "</Type>\n");
1250 		sbuf_printf(sb, "%s<Status>Total=%u, Online=%u</Status>\n",
1251 		    indent, sc->sc_ndisks, g_stripe_nvalid(sc));
1252 		sbuf_printf(sb, "%s<State>", indent);
1253 		if (sc->sc_provider != NULL && sc->sc_provider->error == 0)
1254 			sbuf_cat(sb, "UP");
1255 		else
1256 			sbuf_cat(sb, "DOWN");
1257 		sbuf_cat(sb, "</State>\n");
1258 	}
1259 }
1260 
1261 DECLARE_GEOM_CLASS(g_stripe_class, g_stripe);
1262 MODULE_VERSION(geom_stripe, 0);
1263