xref: /freebsd/sys/geom/stripe/g_stripe.c (revision e39e854e27f53a784c3982cbeb68f4ad1cfd9162)
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 <vm/uma.h>
41 #include <geom/geom.h>
42 #include <geom/stripe/g_stripe.h>
43 
44 FEATURE(geom_stripe, "GEOM striping support");
45 
46 static MALLOC_DEFINE(M_STRIPE, "stripe_data", "GEOM_STRIPE Data");
47 
48 static uma_zone_t g_stripe_zone;
49 
50 static int g_stripe_destroy(struct g_stripe_softc *sc, boolean_t force);
51 static int g_stripe_destroy_geom(struct gctl_req *req, struct g_class *mp,
52     struct g_geom *gp);
53 
54 static g_taste_t g_stripe_taste;
55 static g_ctl_req_t g_stripe_config;
56 static g_dumpconf_t g_stripe_dumpconf;
57 static g_init_t g_stripe_init;
58 static g_fini_t g_stripe_fini;
59 
60 struct g_class g_stripe_class = {
61 	.name = G_STRIPE_CLASS_NAME,
62 	.version = G_VERSION,
63 	.ctlreq = g_stripe_config,
64 	.taste = g_stripe_taste,
65 	.destroy_geom = g_stripe_destroy_geom,
66 	.init = g_stripe_init,
67 	.fini = g_stripe_fini
68 };
69 
70 SYSCTL_DECL(_kern_geom);
71 static SYSCTL_NODE(_kern_geom, OID_AUTO, stripe, CTLFLAG_RW, 0,
72     "GEOM_STRIPE stuff");
73 static u_int g_stripe_debug = 0;
74 TUNABLE_INT("kern.geom.stripe.debug", &g_stripe_debug);
75 SYSCTL_UINT(_kern_geom_stripe, OID_AUTO, debug, CTLFLAG_RW, &g_stripe_debug, 0,
76     "Debug level");
77 static int g_stripe_fast = 0;
78 TUNABLE_INT("kern.geom.stripe.fast", &g_stripe_fast);
79 static int
80 g_sysctl_stripe_fast(SYSCTL_HANDLER_ARGS)
81 {
82 	int error, fast;
83 
84 	fast = g_stripe_fast;
85 	error = sysctl_handle_int(oidp, &fast, 0, req);
86 	if (error == 0 && req->newptr != NULL)
87 		g_stripe_fast = fast;
88 	return (error);
89 }
90 SYSCTL_PROC(_kern_geom_stripe, OID_AUTO, fast, CTLTYPE_INT | CTLFLAG_RW,
91     NULL, 0, g_sysctl_stripe_fast, "I", "Fast, but memory-consuming, mode");
92 static u_int g_stripe_maxmem = MAXPHYS * 100;
93 TUNABLE_INT("kern.geom.stripe.maxmem", &g_stripe_maxmem);
94 SYSCTL_UINT(_kern_geom_stripe, OID_AUTO, maxmem, CTLFLAG_RD, &g_stripe_maxmem,
95     0, "Maximum memory that can be allocated in \"fast\" mode (in bytes)");
96 static u_int g_stripe_fast_failed = 0;
97 SYSCTL_UINT(_kern_geom_stripe, OID_AUTO, fast_failed, CTLFLAG_RD,
98     &g_stripe_fast_failed, 0, "How many times \"fast\" mode failed");
99 
100 /*
101  * Greatest Common Divisor.
102  */
103 static u_int
104 gcd(u_int a, u_int b)
105 {
106 	u_int c;
107 
108 	while (b != 0) {
109 		c = a;
110 		a = b;
111 		b = (c % b);
112 	}
113 	return (a);
114 }
115 
116 /*
117  * Least Common Multiple.
118  */
119 static u_int
120 lcm(u_int a, u_int b)
121 {
122 
123 	return ((a * b) / gcd(a, b));
124 }
125 
126 static void
127 g_stripe_init(struct g_class *mp __unused)
128 {
129 
130 	g_stripe_zone = uma_zcreate("g_stripe_zone", MAXPHYS, NULL, NULL,
131 	    NULL, NULL, 0, 0);
132 	g_stripe_maxmem -= g_stripe_maxmem % MAXPHYS;
133 	uma_zone_set_max(g_stripe_zone, g_stripe_maxmem / MAXPHYS);
134 }
135 
136 static void
137 g_stripe_fini(struct g_class *mp __unused)
138 {
139 
140 	uma_zdestroy(g_stripe_zone);
141 }
142 
143 /*
144  * Return the number of valid disks.
145  */
146 static u_int
147 g_stripe_nvalid(struct g_stripe_softc *sc)
148 {
149 	u_int i, no;
150 
151 	no = 0;
152 	for (i = 0; i < sc->sc_ndisks; i++) {
153 		if (sc->sc_disks[i] != NULL)
154 			no++;
155 	}
156 
157 	return (no);
158 }
159 
160 static void
161 g_stripe_remove_disk(struct g_consumer *cp)
162 {
163 	struct g_stripe_softc *sc;
164 
165 	g_topology_assert();
166 	KASSERT(cp != NULL, ("Non-valid disk in %s.", __func__));
167 	sc = (struct g_stripe_softc *)cp->geom->softc;
168 	KASSERT(sc != NULL, ("NULL sc in %s.", __func__));
169 
170 	if (cp->private == NULL) {
171 		G_STRIPE_DEBUG(0, "Disk %s removed from %s.",
172 		    cp->provider->name, sc->sc_name);
173 		cp->private = (void *)(uintptr_t)-1;
174 	}
175 
176 	if (sc->sc_provider != NULL) {
177 		sc->sc_provider->flags |= G_PF_WITHER;
178 		G_STRIPE_DEBUG(0, "Device %s deactivated.",
179 		    sc->sc_provider->name);
180 		g_orphan_provider(sc->sc_provider, ENXIO);
181 		sc->sc_provider = NULL;
182 	}
183 
184 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
185 		return;
186 	sc->sc_disks[cp->index] = NULL;
187 	cp->index = 0;
188 	g_detach(cp);
189 	g_destroy_consumer(cp);
190 	/* If there are no valid disks anymore, remove device. */
191 	if (LIST_EMPTY(&sc->sc_geom->consumer))
192 		g_stripe_destroy(sc, 1);
193 }
194 
195 static void
196 g_stripe_orphan(struct g_consumer *cp)
197 {
198 	struct g_stripe_softc *sc;
199 	struct g_geom *gp;
200 
201 	g_topology_assert();
202 	gp = cp->geom;
203 	sc = gp->softc;
204 	if (sc == NULL)
205 		return;
206 
207 	g_stripe_remove_disk(cp);
208 }
209 
210 static int
211 g_stripe_access(struct g_provider *pp, int dr, int dw, int de)
212 {
213 	struct g_consumer *cp1, *cp2, *tmp;
214 	struct g_stripe_softc *sc;
215 	struct g_geom *gp;
216 	int error;
217 
218 	g_topology_assert();
219 	gp = pp->geom;
220 	sc = gp->softc;
221 	KASSERT(sc != NULL, ("NULL sc in %s.", __func__));
222 
223 	/* On first open, grab an extra "exclusive" bit */
224 	if (pp->acr == 0 && pp->acw == 0 && pp->ace == 0)
225 		de++;
226 	/* ... and let go of it on last close */
227 	if ((pp->acr + dr) == 0 && (pp->acw + dw) == 0 && (pp->ace + de) == 0)
228 		de--;
229 
230 	LIST_FOREACH_SAFE(cp1, &gp->consumer, consumer, tmp) {
231 		error = g_access(cp1, dr, dw, de);
232 		if (error != 0)
233 			goto fail;
234 		if (cp1->acr == 0 && cp1->acw == 0 && cp1->ace == 0 &&
235 		    cp1->private != NULL) {
236 			g_stripe_remove_disk(cp1); /* May destroy geom. */
237 		}
238 	}
239 	return (0);
240 
241 fail:
242 	LIST_FOREACH(cp2, &gp->consumer, consumer) {
243 		if (cp1 == cp2)
244 			break;
245 		g_access(cp2, -dr, -dw, -de);
246 	}
247 	return (error);
248 }
249 
250 static void
251 g_stripe_copy(struct g_stripe_softc *sc, char *src, char *dst, off_t offset,
252     off_t length, int mode)
253 {
254 	u_int stripesize;
255 	size_t len;
256 
257 	stripesize = sc->sc_stripesize;
258 	len = (size_t)(stripesize - (offset & (stripesize - 1)));
259 	do {
260 		bcopy(src, dst, len);
261 		if (mode) {
262 			dst += len + stripesize * (sc->sc_ndisks - 1);
263 			src += len;
264 		} else {
265 			dst += len;
266 			src += len + stripesize * (sc->sc_ndisks - 1);
267 		}
268 		length -= len;
269 		KASSERT(length >= 0,
270 		    ("Length < 0 (stripesize=%zu, offset=%jd, length=%jd).",
271 		    (size_t)stripesize, (intmax_t)offset, (intmax_t)length));
272 		if (length > stripesize)
273 			len = stripesize;
274 		else
275 			len = length;
276 	} while (length > 0);
277 }
278 
279 static void
280 g_stripe_done(struct bio *bp)
281 {
282 	struct g_stripe_softc *sc;
283 	struct bio *pbp;
284 
285 	pbp = bp->bio_parent;
286 	sc = pbp->bio_to->geom->softc;
287 	if (pbp->bio_error == 0)
288 		pbp->bio_error = bp->bio_error;
289 	pbp->bio_completed += bp->bio_completed;
290 	if (bp->bio_cmd == BIO_READ && bp->bio_caller1 != NULL) {
291 		g_stripe_copy(sc, bp->bio_data, bp->bio_caller1, bp->bio_offset,
292 		    bp->bio_length, 1);
293 		bp->bio_data = bp->bio_caller1;
294 		bp->bio_caller1 = NULL;
295 	}
296 	g_destroy_bio(bp);
297 	pbp->bio_inbed++;
298 	if (pbp->bio_children == pbp->bio_inbed) {
299 		if (pbp->bio_driver1 != NULL)
300 			uma_zfree(g_stripe_zone, pbp->bio_driver1);
301 		g_io_deliver(pbp, pbp->bio_error);
302 	}
303 }
304 
305 static int
306 g_stripe_start_fast(struct bio *bp, u_int no, off_t offset, off_t length)
307 {
308 	TAILQ_HEAD(, bio) queue = TAILQ_HEAD_INITIALIZER(queue);
309 	u_int nparts = 0, stripesize;
310 	struct g_stripe_softc *sc;
311 	char *addr, *data = NULL;
312 	struct bio *cbp;
313 	int error;
314 
315 	sc = bp->bio_to->geom->softc;
316 
317 	addr = bp->bio_data;
318 	stripesize = sc->sc_stripesize;
319 
320 	cbp = g_clone_bio(bp);
321 	if (cbp == NULL) {
322 		error = ENOMEM;
323 		goto failure;
324 	}
325 	TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
326 	nparts++;
327 	/*
328 	 * Fill in the component buf structure.
329 	 */
330 	cbp->bio_done = g_stripe_done;
331 	cbp->bio_offset = offset;
332 	cbp->bio_data = addr;
333 	cbp->bio_caller1 = NULL;
334 	cbp->bio_length = length;
335 	cbp->bio_caller2 = sc->sc_disks[no];
336 
337 	/* offset -= offset % stripesize; */
338 	offset -= offset & (stripesize - 1);
339 	addr += length;
340 	length = bp->bio_length - length;
341 	for (no++; length > 0; no++, length -= stripesize, addr += stripesize) {
342 		if (no > sc->sc_ndisks - 1) {
343 			no = 0;
344 			offset += stripesize;
345 		}
346 		if (nparts >= sc->sc_ndisks) {
347 			cbp = TAILQ_NEXT(cbp, bio_queue);
348 			if (cbp == NULL)
349 				cbp = TAILQ_FIRST(&queue);
350 			nparts++;
351 			/*
352 			 * Update bio structure.
353 			 */
354 			/*
355 			 * MIN() is in case when
356 			 * (bp->bio_length % sc->sc_stripesize) != 0.
357 			 */
358 			cbp->bio_length += MIN(stripesize, length);
359 			if (cbp->bio_caller1 == NULL) {
360 				cbp->bio_caller1 = cbp->bio_data;
361 				cbp->bio_data = NULL;
362 				if (data == NULL) {
363 					data = uma_zalloc(g_stripe_zone,
364 					    M_NOWAIT);
365 					if (data == NULL) {
366 						error = ENOMEM;
367 						goto failure;
368 					}
369 				}
370 			}
371 		} else {
372 			cbp = g_clone_bio(bp);
373 			if (cbp == NULL) {
374 				error = ENOMEM;
375 				goto failure;
376 			}
377 			TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
378 			nparts++;
379 			/*
380 			 * Fill in the component buf structure.
381 			 */
382 			cbp->bio_done = g_stripe_done;
383 			cbp->bio_offset = offset;
384 			cbp->bio_data = addr;
385 			cbp->bio_caller1 = NULL;
386 			/*
387 			 * MIN() is in case when
388 			 * (bp->bio_length % sc->sc_stripesize) != 0.
389 			 */
390 			cbp->bio_length = MIN(stripesize, length);
391 			cbp->bio_caller2 = sc->sc_disks[no];
392 		}
393 	}
394 	if (data != NULL)
395 		bp->bio_driver1 = data;
396 	/*
397 	 * Fire off all allocated requests!
398 	 */
399 	while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
400 		struct g_consumer *cp;
401 
402 		TAILQ_REMOVE(&queue, cbp, bio_queue);
403 		cp = cbp->bio_caller2;
404 		cbp->bio_caller2 = NULL;
405 		cbp->bio_to = cp->provider;
406 		if (cbp->bio_caller1 != NULL) {
407 			cbp->bio_data = data;
408 			if (bp->bio_cmd == BIO_WRITE) {
409 				g_stripe_copy(sc, cbp->bio_caller1, data,
410 				    cbp->bio_offset, cbp->bio_length, 0);
411 			}
412 			data += cbp->bio_length;
413 		}
414 		G_STRIPE_LOGREQ(cbp, "Sending request.");
415 		g_io_request(cbp, cp);
416 	}
417 	return (0);
418 failure:
419 	if (data != NULL)
420 		uma_zfree(g_stripe_zone, data);
421 	while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
422 		TAILQ_REMOVE(&queue, cbp, bio_queue);
423 		if (cbp->bio_caller1 != NULL) {
424 			cbp->bio_data = cbp->bio_caller1;
425 			cbp->bio_caller1 = NULL;
426 		}
427 		bp->bio_children--;
428 		g_destroy_bio(cbp);
429 	}
430 	return (error);
431 }
432 
433 static int
434 g_stripe_start_economic(struct bio *bp, u_int no, off_t offset, off_t length)
435 {
436 	TAILQ_HEAD(, bio) queue = TAILQ_HEAD_INITIALIZER(queue);
437 	struct g_stripe_softc *sc;
438 	uint32_t stripesize;
439 	struct bio *cbp;
440 	char *addr;
441 	int error;
442 
443 	sc = bp->bio_to->geom->softc;
444 
445 	addr = bp->bio_data;
446 	stripesize = sc->sc_stripesize;
447 
448 	cbp = g_clone_bio(bp);
449 	if (cbp == NULL) {
450 		error = ENOMEM;
451 		goto failure;
452 	}
453 	TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
454 	/*
455 	 * Fill in the component buf structure.
456 	 */
457 	cbp->bio_done = g_std_done;
458 	cbp->bio_offset = offset;
459 	cbp->bio_data = addr;
460 	cbp->bio_length = length;
461 	cbp->bio_caller2 = sc->sc_disks[no];
462 
463 	/* offset -= offset % stripesize; */
464 	offset -= offset & (stripesize - 1);
465 	addr += length;
466 	length = bp->bio_length - length;
467 	for (no++; length > 0; no++, length -= stripesize, addr += stripesize) {
468 		if (no > sc->sc_ndisks - 1) {
469 			no = 0;
470 			offset += stripesize;
471 		}
472 		cbp = g_clone_bio(bp);
473 		if (cbp == NULL) {
474 			error = ENOMEM;
475 			goto failure;
476 		}
477 		TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
478 
479 		/*
480 		 * Fill in the component buf structure.
481 		 */
482 		cbp->bio_done = g_std_done;
483 		cbp->bio_offset = offset;
484 		cbp->bio_data = addr;
485 		/*
486 		 * MIN() is in case when
487 		 * (bp->bio_length % sc->sc_stripesize) != 0.
488 		 */
489 		cbp->bio_length = MIN(stripesize, length);
490 
491 		cbp->bio_caller2 = sc->sc_disks[no];
492 	}
493 	/*
494 	 * Fire off all allocated requests!
495 	 */
496 	while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
497 		struct g_consumer *cp;
498 
499 		TAILQ_REMOVE(&queue, cbp, bio_queue);
500 		cp = cbp->bio_caller2;
501 		cbp->bio_caller2 = NULL;
502 		cbp->bio_to = cp->provider;
503 		G_STRIPE_LOGREQ(cbp, "Sending request.");
504 		g_io_request(cbp, cp);
505 	}
506 	return (0);
507 failure:
508 	while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
509 		TAILQ_REMOVE(&queue, cbp, bio_queue);
510 		bp->bio_children--;
511 		g_destroy_bio(cbp);
512 	}
513 	return (error);
514 }
515 
516 static void
517 g_stripe_flush(struct g_stripe_softc *sc, struct bio *bp)
518 {
519 	struct bio_queue_head queue;
520 	struct g_consumer *cp;
521 	struct bio *cbp;
522 	u_int no;
523 
524 	bioq_init(&queue);
525 	for (no = 0; no < sc->sc_ndisks; no++) {
526 		cbp = g_clone_bio(bp);
527 		if (cbp == NULL) {
528 			for (cbp = bioq_first(&queue); cbp != NULL;
529 			    cbp = bioq_first(&queue)) {
530 				bioq_remove(&queue, cbp);
531 				g_destroy_bio(cbp);
532 			}
533 			if (bp->bio_error == 0)
534 				bp->bio_error = ENOMEM;
535 			g_io_deliver(bp, bp->bio_error);
536 			return;
537 		}
538 		bioq_insert_tail(&queue, cbp);
539 		cbp->bio_done = g_std_done;
540 		cbp->bio_caller1 = sc->sc_disks[no];
541 		cbp->bio_to = sc->sc_disks[no]->provider;
542 	}
543 	for (cbp = bioq_first(&queue); cbp != NULL; cbp = bioq_first(&queue)) {
544 		bioq_remove(&queue, cbp);
545 		G_STRIPE_LOGREQ(cbp, "Sending request.");
546 		cp = cbp->bio_caller1;
547 		cbp->bio_caller1 = NULL;
548 		g_io_request(cbp, cp);
549 	}
550 }
551 
552 static void
553 g_stripe_start(struct bio *bp)
554 {
555 	off_t offset, start, length, nstripe;
556 	struct g_stripe_softc *sc;
557 	u_int no, stripesize;
558 	int error, fast = 0;
559 
560 	sc = bp->bio_to->geom->softc;
561 	/*
562 	 * If sc == NULL, provider's error should be set and g_stripe_start()
563 	 * should not be called at all.
564 	 */
565 	KASSERT(sc != NULL,
566 	    ("Provider's error should be set (error=%d)(device=%s).",
567 	    bp->bio_to->error, bp->bio_to->name));
568 
569 	G_STRIPE_LOGREQ(bp, "Request received.");
570 
571 	switch (bp->bio_cmd) {
572 	case BIO_READ:
573 	case BIO_WRITE:
574 	case BIO_DELETE:
575 		break;
576 	case BIO_FLUSH:
577 		g_stripe_flush(sc, bp);
578 		return;
579 	case BIO_GETATTR:
580 		/* To which provider it should be delivered? */
581 	default:
582 		g_io_deliver(bp, EOPNOTSUPP);
583 		return;
584 	}
585 
586 	stripesize = sc->sc_stripesize;
587 
588 	/*
589 	 * Calculations are quite messy, but fast I hope.
590 	 */
591 
592 	/* Stripe number. */
593 	/* nstripe = bp->bio_offset / stripesize; */
594 	nstripe = bp->bio_offset >> (off_t)sc->sc_stripebits;
595 	/* Disk number. */
596 	no = nstripe % sc->sc_ndisks;
597 	/* Start position in stripe. */
598 	/* start = bp->bio_offset % stripesize; */
599 	start = bp->bio_offset & (stripesize - 1);
600 	/* Start position in disk. */
601 	/* offset = (nstripe / sc->sc_ndisks) * stripesize + start; */
602 	offset = ((nstripe / sc->sc_ndisks) << sc->sc_stripebits) + start;
603 	/* Length of data to operate. */
604 	length = MIN(bp->bio_length, stripesize - start);
605 
606 	/*
607 	 * Do use "fast" mode when:
608 	 * 1. "Fast" mode is ON.
609 	 * and
610 	 * 2. Request size is less than or equal to MAXPHYS,
611 	 *    which should always be true.
612 	 * and
613 	 * 3. Request size is bigger than stripesize * ndisks. If it isn't,
614 	 *    there will be no need to send more than one I/O request to
615 	 *    a provider, so there is nothing to optmize.
616 	 */
617 	if (g_stripe_fast && bp->bio_length <= MAXPHYS &&
618 	    bp->bio_length >= stripesize * sc->sc_ndisks) {
619 		fast = 1;
620 	}
621 	error = 0;
622 	if (fast) {
623 		error = g_stripe_start_fast(bp, no, offset, length);
624 		if (error != 0)
625 			g_stripe_fast_failed++;
626 	}
627 	/*
628 	 * Do use "economic" when:
629 	 * 1. "Economic" mode is ON.
630 	 * or
631 	 * 2. "Fast" mode failed. It can only fail if there is no memory.
632 	 */
633 	if (!fast || error != 0)
634 		error = g_stripe_start_economic(bp, no, offset, length);
635 	if (error != 0) {
636 		if (bp->bio_error == 0)
637 			bp->bio_error = error;
638 		g_io_deliver(bp, bp->bio_error);
639 	}
640 }
641 
642 static void
643 g_stripe_check_and_run(struct g_stripe_softc *sc)
644 {
645 	off_t mediasize, ms;
646 	u_int no, sectorsize = 0;
647 
648 	g_topology_assert();
649 	if (g_stripe_nvalid(sc) != sc->sc_ndisks)
650 		return;
651 
652 	sc->sc_provider = g_new_providerf(sc->sc_geom, "stripe/%s",
653 	    sc->sc_name);
654 	/*
655 	 * Find the smallest disk.
656 	 */
657 	mediasize = sc->sc_disks[0]->provider->mediasize;
658 	if (sc->sc_type == G_STRIPE_TYPE_AUTOMATIC)
659 		mediasize -= sc->sc_disks[0]->provider->sectorsize;
660 	mediasize -= mediasize % sc->sc_stripesize;
661 	sectorsize = sc->sc_disks[0]->provider->sectorsize;
662 	for (no = 1; no < sc->sc_ndisks; no++) {
663 		ms = sc->sc_disks[no]->provider->mediasize;
664 		if (sc->sc_type == G_STRIPE_TYPE_AUTOMATIC)
665 			ms -= sc->sc_disks[no]->provider->sectorsize;
666 		ms -= ms % sc->sc_stripesize;
667 		if (ms < mediasize)
668 			mediasize = ms;
669 		sectorsize = lcm(sectorsize,
670 		    sc->sc_disks[no]->provider->sectorsize);
671 	}
672 	sc->sc_provider->sectorsize = sectorsize;
673 	sc->sc_provider->mediasize = mediasize * sc->sc_ndisks;
674 	sc->sc_provider->stripesize = sc->sc_stripesize;
675 	sc->sc_provider->stripeoffset = 0;
676 	g_error_provider(sc->sc_provider, 0);
677 
678 	G_STRIPE_DEBUG(0, "Device %s activated.", sc->sc_provider->name);
679 }
680 
681 static int
682 g_stripe_read_metadata(struct g_consumer *cp, struct g_stripe_metadata *md)
683 {
684 	struct g_provider *pp;
685 	u_char *buf;
686 	int error;
687 
688 	g_topology_assert();
689 
690 	error = g_access(cp, 1, 0, 0);
691 	if (error != 0)
692 		return (error);
693 	pp = cp->provider;
694 	g_topology_unlock();
695 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
696 	    &error);
697 	g_topology_lock();
698 	g_access(cp, -1, 0, 0);
699 	if (buf == NULL)
700 		return (error);
701 
702 	/* Decode metadata. */
703 	stripe_metadata_decode(buf, md);
704 	g_free(buf);
705 
706 	return (0);
707 }
708 
709 /*
710  * Add disk to given device.
711  */
712 static int
713 g_stripe_add_disk(struct g_stripe_softc *sc, struct g_provider *pp, u_int no)
714 {
715 	struct g_consumer *cp, *fcp;
716 	struct g_geom *gp;
717 	int error;
718 
719 	g_topology_assert();
720 	/* Metadata corrupted? */
721 	if (no >= sc->sc_ndisks)
722 		return (EINVAL);
723 
724 	/* Check if disk is not already attached. */
725 	if (sc->sc_disks[no] != NULL)
726 		return (EEXIST);
727 
728 	gp = sc->sc_geom;
729 	fcp = LIST_FIRST(&gp->consumer);
730 
731 	cp = g_new_consumer(gp);
732 	cp->private = NULL;
733 	cp->index = no;
734 	error = g_attach(cp, pp);
735 	if (error != 0) {
736 		g_destroy_consumer(cp);
737 		return (error);
738 	}
739 
740 	if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0)) {
741 		error = g_access(cp, fcp->acr, fcp->acw, fcp->ace);
742 		if (error != 0) {
743 			g_detach(cp);
744 			g_destroy_consumer(cp);
745 			return (error);
746 		}
747 	}
748 	if (sc->sc_type == G_STRIPE_TYPE_AUTOMATIC) {
749 		struct g_stripe_metadata md;
750 
751 		/* Reread metadata. */
752 		error = g_stripe_read_metadata(cp, &md);
753 		if (error != 0)
754 			goto fail;
755 
756 		if (strcmp(md.md_magic, G_STRIPE_MAGIC) != 0 ||
757 		    strcmp(md.md_name, sc->sc_name) != 0 ||
758 		    md.md_id != sc->sc_id) {
759 			G_STRIPE_DEBUG(0, "Metadata on %s changed.", pp->name);
760 			goto fail;
761 		}
762 	}
763 
764 	sc->sc_disks[no] = cp;
765 	G_STRIPE_DEBUG(0, "Disk %s attached to %s.", pp->name, sc->sc_name);
766 	g_stripe_check_and_run(sc);
767 
768 	return (0);
769 fail:
770 	if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0))
771 		g_access(cp, -fcp->acr, -fcp->acw, -fcp->ace);
772 	g_detach(cp);
773 	g_destroy_consumer(cp);
774 	return (error);
775 }
776 
777 static struct g_geom *
778 g_stripe_create(struct g_class *mp, const struct g_stripe_metadata *md,
779     u_int type)
780 {
781 	struct g_stripe_softc *sc;
782 	struct g_geom *gp;
783 	u_int no;
784 
785 	g_topology_assert();
786 	G_STRIPE_DEBUG(1, "Creating device %s (id=%u).", md->md_name,
787 	    md->md_id);
788 
789 	/* Two disks is minimum. */
790 	if (md->md_all < 2) {
791 		G_STRIPE_DEBUG(0, "Too few disks defined for %s.", md->md_name);
792 		return (NULL);
793 	}
794 #if 0
795 	/* Stripe size have to be grater than or equal to sector size. */
796 	if (md->md_stripesize < sectorsize) {
797 		G_STRIPE_DEBUG(0, "Invalid stripe size for %s.", md->md_name);
798 		return (NULL);
799 	}
800 #endif
801 	/* Stripe size have to be power of 2. */
802 	if (!powerof2(md->md_stripesize)) {
803 		G_STRIPE_DEBUG(0, "Invalid stripe size for %s.", md->md_name);
804 		return (NULL);
805 	}
806 
807 	/* Check for duplicate unit */
808 	LIST_FOREACH(gp, &mp->geom, geom) {
809 		sc = gp->softc;
810 		if (sc != NULL && strcmp(sc->sc_name, md->md_name) == 0) {
811 			G_STRIPE_DEBUG(0, "Device %s already configured.",
812 			    sc->sc_name);
813 			return (NULL);
814 		}
815 	}
816 	gp = g_new_geomf(mp, "%s", md->md_name);
817 	sc = malloc(sizeof(*sc), M_STRIPE, M_WAITOK | M_ZERO);
818 	gp->start = g_stripe_start;
819 	gp->spoiled = g_stripe_orphan;
820 	gp->orphan = g_stripe_orphan;
821 	gp->access = g_stripe_access;
822 	gp->dumpconf = g_stripe_dumpconf;
823 
824 	sc->sc_id = md->md_id;
825 	sc->sc_stripesize = md->md_stripesize;
826 	sc->sc_stripebits = bitcount32(sc->sc_stripesize - 1);
827 	sc->sc_ndisks = md->md_all;
828 	sc->sc_disks = malloc(sizeof(struct g_consumer *) * sc->sc_ndisks,
829 	    M_STRIPE, M_WAITOK | M_ZERO);
830 	for (no = 0; no < sc->sc_ndisks; no++)
831 		sc->sc_disks[no] = NULL;
832 	sc->sc_type = type;
833 
834 	gp->softc = sc;
835 	sc->sc_geom = gp;
836 	sc->sc_provider = NULL;
837 
838 	G_STRIPE_DEBUG(0, "Device %s created (id=%u).", sc->sc_name, sc->sc_id);
839 
840 	return (gp);
841 }
842 
843 static int
844 g_stripe_destroy(struct g_stripe_softc *sc, boolean_t force)
845 {
846 	struct g_provider *pp;
847 	struct g_consumer *cp, *cp1;
848 	struct g_geom *gp;
849 
850 	g_topology_assert();
851 
852 	if (sc == NULL)
853 		return (ENXIO);
854 
855 	pp = sc->sc_provider;
856 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
857 		if (force) {
858 			G_STRIPE_DEBUG(0, "Device %s is still open, so it "
859 			    "can't be definitely removed.", pp->name);
860 		} else {
861 			G_STRIPE_DEBUG(1,
862 			    "Device %s is still open (r%dw%de%d).", pp->name,
863 			    pp->acr, pp->acw, pp->ace);
864 			return (EBUSY);
865 		}
866 	}
867 
868 	gp = sc->sc_geom;
869 	LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp1) {
870 		g_stripe_remove_disk(cp);
871 		if (cp1 == NULL)
872 			return (0);	/* Recursion happened. */
873 	}
874 	if (!LIST_EMPTY(&gp->consumer))
875 		return (EINPROGRESS);
876 
877 	gp->softc = NULL;
878 	KASSERT(sc->sc_provider == NULL, ("Provider still exists? (device=%s)",
879 	    gp->name));
880 	free(sc->sc_disks, M_STRIPE);
881 	free(sc, M_STRIPE);
882 	G_STRIPE_DEBUG(0, "Device %s destroyed.", gp->name);
883 	g_wither_geom(gp, ENXIO);
884 	return (0);
885 }
886 
887 static int
888 g_stripe_destroy_geom(struct gctl_req *req __unused,
889     struct g_class *mp __unused, struct g_geom *gp)
890 {
891 	struct g_stripe_softc *sc;
892 
893 	sc = gp->softc;
894 	return (g_stripe_destroy(sc, 0));
895 }
896 
897 static struct g_geom *
898 g_stripe_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
899 {
900 	struct g_stripe_metadata md;
901 	struct g_stripe_softc *sc;
902 	struct g_consumer *cp;
903 	struct g_geom *gp;
904 	int error;
905 
906 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
907 	g_topology_assert();
908 
909 	/* Skip providers that are already open for writing. */
910 	if (pp->acw > 0)
911 		return (NULL);
912 
913 	G_STRIPE_DEBUG(3, "Tasting %s.", pp->name);
914 
915 	gp = g_new_geomf(mp, "stripe:taste");
916 	gp->start = g_stripe_start;
917 	gp->access = g_stripe_access;
918 	gp->orphan = g_stripe_orphan;
919 	cp = g_new_consumer(gp);
920 	g_attach(cp, pp);
921 	error = g_stripe_read_metadata(cp, &md);
922 	g_detach(cp);
923 	g_destroy_consumer(cp);
924 	g_destroy_geom(gp);
925 	if (error != 0)
926 		return (NULL);
927 	gp = NULL;
928 
929 	if (strcmp(md.md_magic, G_STRIPE_MAGIC) != 0)
930 		return (NULL);
931 	if (md.md_version > G_STRIPE_VERSION) {
932 		printf("geom_stripe.ko module is too old to handle %s.\n",
933 		    pp->name);
934 		return (NULL);
935 	}
936 	/*
937 	 * Backward compatibility:
938 	 */
939 	/* There was no md_provider field in earlier versions of metadata. */
940 	if (md.md_version < 2)
941 		bzero(md.md_provider, sizeof(md.md_provider));
942 	/* There was no md_provsize field in earlier versions of metadata. */
943 	if (md.md_version < 3)
944 		md.md_provsize = pp->mediasize;
945 
946 	if (md.md_provider[0] != '\0' &&
947 	    !g_compare_names(md.md_provider, pp->name))
948 		return (NULL);
949 	if (md.md_provsize != pp->mediasize)
950 		return (NULL);
951 
952 	/*
953 	 * Let's check if device already exists.
954 	 */
955 	sc = NULL;
956 	LIST_FOREACH(gp, &mp->geom, geom) {
957 		sc = gp->softc;
958 		if (sc == NULL)
959 			continue;
960 		if (sc->sc_type != G_STRIPE_TYPE_AUTOMATIC)
961 			continue;
962 		if (strcmp(md.md_name, sc->sc_name) != 0)
963 			continue;
964 		if (md.md_id != sc->sc_id)
965 			continue;
966 		break;
967 	}
968 	if (gp != NULL) {
969 		G_STRIPE_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
970 		error = g_stripe_add_disk(sc, pp, md.md_no);
971 		if (error != 0) {
972 			G_STRIPE_DEBUG(0,
973 			    "Cannot add disk %s to %s (error=%d).", pp->name,
974 			    gp->name, error);
975 			return (NULL);
976 		}
977 	} else {
978 		gp = g_stripe_create(mp, &md, G_STRIPE_TYPE_AUTOMATIC);
979 		if (gp == NULL) {
980 			G_STRIPE_DEBUG(0, "Cannot create device %s.",
981 			    md.md_name);
982 			return (NULL);
983 		}
984 		sc = gp->softc;
985 		G_STRIPE_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
986 		error = g_stripe_add_disk(sc, pp, md.md_no);
987 		if (error != 0) {
988 			G_STRIPE_DEBUG(0,
989 			    "Cannot add disk %s to %s (error=%d).", pp->name,
990 			    gp->name, error);
991 			g_stripe_destroy(sc, 1);
992 			return (NULL);
993 		}
994 	}
995 
996 	return (gp);
997 }
998 
999 static void
1000 g_stripe_ctl_create(struct gctl_req *req, struct g_class *mp)
1001 {
1002 	u_int attached, no;
1003 	struct g_stripe_metadata md;
1004 	struct g_provider *pp;
1005 	struct g_stripe_softc *sc;
1006 	struct g_geom *gp;
1007 	struct sbuf *sb;
1008 	intmax_t *stripesize;
1009 	const char *name;
1010 	char param[16];
1011 	int *nargs;
1012 
1013 	g_topology_assert();
1014 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
1015 	if (nargs == NULL) {
1016 		gctl_error(req, "No '%s' argument.", "nargs");
1017 		return;
1018 	}
1019 	if (*nargs <= 2) {
1020 		gctl_error(req, "Too few arguments.");
1021 		return;
1022 	}
1023 
1024 	strlcpy(md.md_magic, G_STRIPE_MAGIC, sizeof(md.md_magic));
1025 	md.md_version = G_STRIPE_VERSION;
1026 	name = gctl_get_asciiparam(req, "arg0");
1027 	if (name == NULL) {
1028 		gctl_error(req, "No 'arg%u' argument.", 0);
1029 		return;
1030 	}
1031 	strlcpy(md.md_name, name, sizeof(md.md_name));
1032 	md.md_id = arc4random();
1033 	md.md_no = 0;
1034 	md.md_all = *nargs - 1;
1035 	stripesize = gctl_get_paraml(req, "stripesize", sizeof(*stripesize));
1036 	if (stripesize == NULL) {
1037 		gctl_error(req, "No '%s' argument.", "stripesize");
1038 		return;
1039 	}
1040 	md.md_stripesize = *stripesize;
1041 	bzero(md.md_provider, sizeof(md.md_provider));
1042 	/* This field is not important here. */
1043 	md.md_provsize = 0;
1044 
1045 	/* Check all providers are valid */
1046 	for (no = 1; no < *nargs; no++) {
1047 		snprintf(param, sizeof(param), "arg%u", no);
1048 		name = gctl_get_asciiparam(req, param);
1049 		if (name == NULL) {
1050 			gctl_error(req, "No 'arg%u' argument.", no);
1051 			return;
1052 		}
1053 		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
1054 			name += strlen("/dev/");
1055 		pp = g_provider_by_name(name);
1056 		if (pp == NULL) {
1057 			G_STRIPE_DEBUG(1, "Disk %s is invalid.", name);
1058 			gctl_error(req, "Disk %s is invalid.", name);
1059 			return;
1060 		}
1061 	}
1062 
1063 	gp = g_stripe_create(mp, &md, G_STRIPE_TYPE_MANUAL);
1064 	if (gp == NULL) {
1065 		gctl_error(req, "Can't configure %s.", md.md_name);
1066 		return;
1067 	}
1068 
1069 	sc = gp->softc;
1070 	sb = sbuf_new_auto();
1071 	sbuf_printf(sb, "Can't attach disk(s) to %s:", gp->name);
1072 	for (attached = 0, no = 1; no < *nargs; no++) {
1073 		snprintf(param, sizeof(param), "arg%u", no);
1074 		name = gctl_get_asciiparam(req, param);
1075 		if (name == NULL) {
1076 			gctl_error(req, "No 'arg%u' argument.", no);
1077 			continue;
1078 		}
1079 		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
1080 			name += strlen("/dev/");
1081 		pp = g_provider_by_name(name);
1082 		KASSERT(pp != NULL, ("Provider %s disappear?!", name));
1083 		if (g_stripe_add_disk(sc, pp, no - 1) != 0) {
1084 			G_STRIPE_DEBUG(1, "Disk %u (%s) not attached to %s.",
1085 			    no, pp->name, gp->name);
1086 			sbuf_printf(sb, " %s", pp->name);
1087 			continue;
1088 		}
1089 		attached++;
1090 	}
1091 	sbuf_finish(sb);
1092 	if (md.md_all != attached) {
1093 		g_stripe_destroy(gp->softc, 1);
1094 		gctl_error(req, "%s", sbuf_data(sb));
1095 	}
1096 	sbuf_delete(sb);
1097 }
1098 
1099 static struct g_stripe_softc *
1100 g_stripe_find_device(struct g_class *mp, const char *name)
1101 {
1102 	struct g_stripe_softc *sc;
1103 	struct g_geom *gp;
1104 
1105 	LIST_FOREACH(gp, &mp->geom, geom) {
1106 		sc = gp->softc;
1107 		if (sc == NULL)
1108 			continue;
1109 		if (strcmp(sc->sc_name, name) == 0)
1110 			return (sc);
1111 	}
1112 	return (NULL);
1113 }
1114 
1115 static void
1116 g_stripe_ctl_destroy(struct gctl_req *req, struct g_class *mp)
1117 {
1118 	struct g_stripe_softc *sc;
1119 	int *force, *nargs, error;
1120 	const char *name;
1121 	char param[16];
1122 	u_int i;
1123 
1124 	g_topology_assert();
1125 
1126 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
1127 	if (nargs == NULL) {
1128 		gctl_error(req, "No '%s' argument.", "nargs");
1129 		return;
1130 	}
1131 	if (*nargs <= 0) {
1132 		gctl_error(req, "Missing device(s).");
1133 		return;
1134 	}
1135 	force = gctl_get_paraml(req, "force", sizeof(*force));
1136 	if (force == NULL) {
1137 		gctl_error(req, "No '%s' argument.", "force");
1138 		return;
1139 	}
1140 
1141 	for (i = 0; i < (u_int)*nargs; i++) {
1142 		snprintf(param, sizeof(param), "arg%u", i);
1143 		name = gctl_get_asciiparam(req, param);
1144 		if (name == NULL) {
1145 			gctl_error(req, "No 'arg%u' argument.", i);
1146 			return;
1147 		}
1148 		sc = g_stripe_find_device(mp, name);
1149 		if (sc == NULL) {
1150 			gctl_error(req, "No such device: %s.", name);
1151 			return;
1152 		}
1153 		error = g_stripe_destroy(sc, *force);
1154 		if (error != 0) {
1155 			gctl_error(req, "Cannot destroy device %s (error=%d).",
1156 			    sc->sc_name, error);
1157 			return;
1158 		}
1159 	}
1160 }
1161 
1162 static void
1163 g_stripe_config(struct gctl_req *req, struct g_class *mp, const char *verb)
1164 {
1165 	uint32_t *version;
1166 
1167 	g_topology_assert();
1168 
1169 	version = gctl_get_paraml(req, "version", sizeof(*version));
1170 	if (version == NULL) {
1171 		gctl_error(req, "No '%s' argument.", "version");
1172 		return;
1173 	}
1174 	if (*version != G_STRIPE_VERSION) {
1175 		gctl_error(req, "Userland and kernel parts are out of sync.");
1176 		return;
1177 	}
1178 
1179 	if (strcmp(verb, "create") == 0) {
1180 		g_stripe_ctl_create(req, mp);
1181 		return;
1182 	} else if (strcmp(verb, "destroy") == 0 ||
1183 	    strcmp(verb, "stop") == 0) {
1184 		g_stripe_ctl_destroy(req, mp);
1185 		return;
1186 	}
1187 
1188 	gctl_error(req, "Unknown verb.");
1189 }
1190 
1191 static void
1192 g_stripe_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
1193     struct g_consumer *cp, struct g_provider *pp)
1194 {
1195 	struct g_stripe_softc *sc;
1196 
1197 	sc = gp->softc;
1198 	if (sc == NULL)
1199 		return;
1200 	if (pp != NULL) {
1201 		/* Nothing here. */
1202 	} else if (cp != NULL) {
1203 		sbuf_printf(sb, "%s<Number>%u</Number>\n", indent,
1204 		    (u_int)cp->index);
1205 	} else {
1206 		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
1207 		sbuf_printf(sb, "%s<Stripesize>%u</Stripesize>\n", indent,
1208 		    (u_int)sc->sc_stripesize);
1209 		sbuf_printf(sb, "%s<Type>", indent);
1210 		switch (sc->sc_type) {
1211 		case G_STRIPE_TYPE_AUTOMATIC:
1212 			sbuf_printf(sb, "AUTOMATIC");
1213 			break;
1214 		case G_STRIPE_TYPE_MANUAL:
1215 			sbuf_printf(sb, "MANUAL");
1216 			break;
1217 		default:
1218 			sbuf_printf(sb, "UNKNOWN");
1219 			break;
1220 		}
1221 		sbuf_printf(sb, "</Type>\n");
1222 		sbuf_printf(sb, "%s<Status>Total=%u, Online=%u</Status>\n",
1223 		    indent, sc->sc_ndisks, g_stripe_nvalid(sc));
1224 		sbuf_printf(sb, "%s<State>", indent);
1225 		if (sc->sc_provider != NULL && sc->sc_provider->error == 0)
1226 			sbuf_printf(sb, "UP");
1227 		else
1228 			sbuf_printf(sb, "DOWN");
1229 		sbuf_printf(sb, "</State>\n");
1230 	}
1231 }
1232 
1233 DECLARE_GEOM_CLASS(g_stripe_class, g_stripe);
1234