xref: /freebsd/sys/geom/geom_subr.c (revision e9ac41698b2f322d55ccf9da50a3596edb2c1800)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2002 Poul-Henning Kamp
5  * Copyright (c) 2002 Networks Associates Technology, Inc.
6  * All rights reserved.
7  *
8  * This software was developed for the FreeBSD Project by Poul-Henning Kamp
9  * and NAI Labs, the Security Research Division of Network Associates, Inc.
10  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
11  * DARPA CHATS research program.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. The names of the authors may not be used to endorse or promote
22  *    products derived from this software without specific prior written
23  *    permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  */
37 
38 #include <sys/cdefs.h>
39 #include "opt_ddb.h"
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/devicestat.h>
44 #include <sys/kernel.h>
45 #include <sys/malloc.h>
46 #include <sys/bio.h>
47 #include <sys/proc.h>
48 #include <sys/kthread.h>
49 #include <sys/lock.h>
50 #include <sys/mutex.h>
51 #include <sys/errno.h>
52 #include <sys/sbuf.h>
53 #include <sys/sdt.h>
54 #include <geom/geom.h>
55 #include <geom/geom_dbg.h>
56 #include <geom/geom_int.h>
57 #include <machine/stdarg.h>
58 
59 #ifdef DDB
60 #include <ddb/ddb.h>
61 #endif
62 
63 #ifdef KDB
64 #include <sys/kdb.h>
65 #endif
66 
67 SDT_PROVIDER_DEFINE(geom);
68 
69 struct class_list_head g_classes = LIST_HEAD_INITIALIZER(g_classes);
70 static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms);
71 char *g_wait_event, *g_wait_up, *g_wait_down;
72 
73 struct g_hh00 {
74 	struct g_class		*mp;
75 	struct g_provider	*pp;
76 	off_t			size;
77 	int			error;
78 	int			post;
79 };
80 
81 void
82 g_dbg_printf(const char *classname, int lvl, struct bio *bp,
83     const char *format,
84     ...)
85 {
86 #ifndef PRINTF_BUFR_SIZE
87 #define PRINTF_BUFR_SIZE 64
88 #endif
89 	char bufr[PRINTF_BUFR_SIZE];
90 	struct sbuf sb, *sbp __unused;
91 	va_list ap;
92 
93 	sbp = sbuf_new(&sb, bufr, sizeof(bufr), SBUF_FIXEDLEN);
94 	KASSERT(sbp != NULL, ("sbuf_new misused?"));
95 
96 	sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
97 
98 	sbuf_cat(&sb, classname);
99 	if (lvl >= 0)
100 		sbuf_printf(&sb, "[%d]", lvl);
101 
102 	va_start(ap, format);
103 	sbuf_vprintf(&sb, format, ap);
104 	va_end(ap);
105 
106 	if (bp != NULL) {
107 		sbuf_putc(&sb, ' ');
108 		g_format_bio(&sb, bp);
109 	}
110 
111 	/* Terminate the debug line with a single '\n'. */
112 	sbuf_nl_terminate(&sb);
113 
114 	/* Flush line to printf. */
115 	sbuf_finish(&sb);
116 	sbuf_delete(&sb);
117 }
118 
119 /*
120  * This event offers a new class a chance to taste all preexisting providers.
121  */
122 static void
123 g_load_class(void *arg, int flag)
124 {
125 	struct g_hh00 *hh;
126 	struct g_class *mp2, *mp;
127 	struct g_geom *gp;
128 	struct g_provider *pp;
129 
130 	g_topology_assert();
131 	if (flag == EV_CANCEL)	/* XXX: can't happen ? */
132 		return;
133 	if (g_shutdown)
134 		return;
135 
136 	hh = arg;
137 	mp = hh->mp;
138 	hh->error = 0;
139 	if (hh->post) {
140 		g_free(hh);
141 		hh = NULL;
142 	}
143 	g_trace(G_T_TOPOLOGY, "g_load_class(%s)", mp->name);
144 	KASSERT(mp->name != NULL && *mp->name != '\0',
145 	    ("GEOM class has no name"));
146 	LIST_FOREACH(mp2, &g_classes, class) {
147 		if (mp2 == mp) {
148 			printf("The GEOM class %s is already loaded.\n",
149 			    mp2->name);
150 			if (hh != NULL)
151 				hh->error = EEXIST;
152 			return;
153 		} else if (strcmp(mp2->name, mp->name) == 0) {
154 			printf("A GEOM class %s is already loaded.\n",
155 			    mp2->name);
156 			if (hh != NULL)
157 				hh->error = EEXIST;
158 			return;
159 		}
160 	}
161 
162 	LIST_INIT(&mp->geom);
163 	LIST_INSERT_HEAD(&g_classes, mp, class);
164 	if (mp->init != NULL)
165 		mp->init(mp);
166 	if (mp->taste == NULL)
167 		return;
168 	LIST_FOREACH(mp2, &g_classes, class) {
169 		if (mp == mp2)
170 			continue;
171 		LIST_FOREACH(gp, &mp2->geom, geom) {
172 			LIST_FOREACH(pp, &gp->provider, provider) {
173 				mp->taste(mp, pp, 0);
174 				g_topology_assert();
175 			}
176 		}
177 	}
178 }
179 
180 static int
181 g_unload_class(struct g_class *mp)
182 {
183 	struct g_geom *gp;
184 	struct g_provider *pp;
185 	struct g_consumer *cp;
186 	int error;
187 
188 	g_topology_lock();
189 	g_trace(G_T_TOPOLOGY, "g_unload_class(%s)", mp->name);
190 retry:
191 	G_VALID_CLASS(mp);
192 	LIST_FOREACH(gp, &mp->geom, geom) {
193 		/* We refuse to unload if anything is open */
194 		LIST_FOREACH(pp, &gp->provider, provider)
195 			if (pp->acr || pp->acw || pp->ace) {
196 				g_topology_unlock();
197 				return (EBUSY);
198 			}
199 		LIST_FOREACH(cp, &gp->consumer, consumer)
200 			if (cp->acr || cp->acw || cp->ace) {
201 				g_topology_unlock();
202 				return (EBUSY);
203 			}
204 		/* If the geom is withering, wait for it to finish. */
205 		if (gp->flags & G_GEOM_WITHER) {
206 			g_topology_sleep(mp, 1);
207 			goto retry;
208 		}
209 	}
210 
211 	/*
212 	 * We allow unloading if we have no geoms, or a class
213 	 * method we can use to get rid of them.
214 	 */
215 	if (!LIST_EMPTY(&mp->geom) && mp->destroy_geom == NULL) {
216 		g_topology_unlock();
217 		return (EOPNOTSUPP);
218 	}
219 
220 	/* Bar new entries */
221 	mp->taste = NULL;
222 
223 	LIST_FOREACH(gp, &mp->geom, geom) {
224 		error = mp->destroy_geom(NULL, mp, gp);
225 		if (error != 0) {
226 			g_topology_unlock();
227 			return (error);
228 		}
229 	}
230 	/* Wait for withering to finish. */
231 	for (;;) {
232 		gp = LIST_FIRST(&mp->geom);
233 		if (gp == NULL)
234 			break;
235 		KASSERT(gp->flags & G_GEOM_WITHER,
236 		   ("Non-withering geom in class %s", mp->name));
237 		g_topology_sleep(mp, 1);
238 	}
239 	G_VALID_CLASS(mp);
240 	if (mp->fini != NULL)
241 		mp->fini(mp);
242 	LIST_REMOVE(mp, class);
243 	g_topology_unlock();
244 
245 	return (0);
246 }
247 
248 int
249 g_modevent(module_t mod, int type, void *data)
250 {
251 	struct g_hh00 *hh;
252 	int error;
253 	static int g_ignition;
254 	struct g_class *mp;
255 
256 	mp = data;
257 	if (mp->version != G_VERSION) {
258 		printf("GEOM class %s has Wrong version %x\n",
259 		    mp->name, mp->version);
260 		return (EINVAL);
261 	}
262 	if (!g_ignition) {
263 		g_ignition++;
264 		g_init();
265 	}
266 	error = EOPNOTSUPP;
267 	switch (type) {
268 	case MOD_LOAD:
269 		g_trace(G_T_TOPOLOGY, "g_modevent(%s, LOAD)", mp->name);
270 		hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
271 		hh->mp = mp;
272 		/*
273 		 * Once the system is not cold, MOD_LOAD calls will be
274 		 * from the userland and the g_event thread will be able
275 		 * to acknowledge their completion.
276 		 */
277 		if (cold) {
278 			hh->post = 1;
279 			error = g_post_event(g_load_class, hh, M_WAITOK, NULL);
280 		} else {
281 			error = g_waitfor_event(g_load_class, hh, M_WAITOK,
282 			    NULL);
283 			if (error == 0)
284 				error = hh->error;
285 			g_free(hh);
286 		}
287 		break;
288 	case MOD_UNLOAD:
289 		g_trace(G_T_TOPOLOGY, "g_modevent(%s, UNLOAD)", mp->name);
290 		error = g_unload_class(mp);
291 		if (error == 0) {
292 			KASSERT(LIST_EMPTY(&mp->geom),
293 			    ("Unloaded class (%s) still has geom", mp->name));
294 		}
295 		break;
296 	}
297 	return (error);
298 }
299 
300 static void
301 g_retaste_event(void *arg, int flag)
302 {
303 	struct g_class *mp, *mp2;
304 	struct g_geom *gp;
305 	struct g_hh00 *hh;
306 	struct g_provider *pp;
307 	struct g_consumer *cp;
308 
309 	g_topology_assert();
310 	if (flag == EV_CANCEL)  /* XXX: can't happen ? */
311 		return;
312 	if (g_shutdown || g_notaste)
313 		return;
314 
315 	hh = arg;
316 	mp = hh->mp;
317 	hh->error = 0;
318 	if (hh->post) {
319 		g_free(hh);
320 		hh = NULL;
321 	}
322 	g_trace(G_T_TOPOLOGY, "g_retaste(%s)", mp->name);
323 
324 	LIST_FOREACH(mp2, &g_classes, class) {
325 		LIST_FOREACH(gp, &mp2->geom, geom) {
326 			LIST_FOREACH(pp, &gp->provider, provider) {
327 				if (pp->acr || pp->acw || pp->ace)
328 					continue;
329 				LIST_FOREACH(cp, &pp->consumers, consumers) {
330 					if (cp->geom->class == mp &&
331 					    (cp->flags & G_CF_ORPHAN) == 0)
332 						break;
333 				}
334 				if (cp != NULL) {
335 					cp->flags |= G_CF_ORPHAN;
336 					g_wither_geom(cp->geom, ENXIO);
337 				}
338 				mp->taste(mp, pp, 0);
339 				g_topology_assert();
340 			}
341 		}
342 	}
343 }
344 
345 int
346 g_retaste(struct g_class *mp)
347 {
348 	struct g_hh00 *hh;
349 	int error;
350 
351 	if (mp->taste == NULL)
352 		return (EINVAL);
353 
354 	hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
355 	hh->mp = mp;
356 
357 	if (cold) {
358 		hh->post = 1;
359 		error = g_post_event(g_retaste_event, hh, M_WAITOK, NULL);
360 	} else {
361 		error = g_waitfor_event(g_retaste_event, hh, M_WAITOK, NULL);
362 		if (error == 0)
363 			error = hh->error;
364 		g_free(hh);
365 	}
366 
367 	return (error);
368 }
369 
370 struct g_geom *
371 g_new_geomf(struct g_class *mp, const char *fmt, ...)
372 {
373 	struct g_geom *gp;
374 	va_list ap;
375 	struct sbuf *sb;
376 
377 	g_topology_assert();
378 	G_VALID_CLASS(mp);
379 	sb = sbuf_new_auto();
380 	va_start(ap, fmt);
381 	sbuf_vprintf(sb, fmt, ap);
382 	va_end(ap);
383 	sbuf_finish(sb);
384 	gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO);
385 	gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
386 	gp->class = mp;
387 	gp->rank = 1;
388 	LIST_INIT(&gp->consumer);
389 	LIST_INIT(&gp->provider);
390 	LIST_INSERT_HEAD(&mp->geom, gp, geom);
391 	TAILQ_INSERT_HEAD(&geoms, gp, geoms);
392 	strcpy(gp->name, sbuf_data(sb));
393 	sbuf_delete(sb);
394 	/* Fill in defaults from class */
395 	gp->start = mp->start;
396 	gp->spoiled = mp->spoiled;
397 	gp->attrchanged = mp->attrchanged;
398 	gp->providergone = mp->providergone;
399 	gp->dumpconf = mp->dumpconf;
400 	gp->access = mp->access;
401 	gp->orphan = mp->orphan;
402 	gp->ioctl = mp->ioctl;
403 	gp->resize = mp->resize;
404 	return (gp);
405 }
406 
407 void
408 g_destroy_geom(struct g_geom *gp)
409 {
410 
411 	g_topology_assert();
412 	G_VALID_GEOM(gp);
413 	g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
414 	KASSERT(LIST_EMPTY(&gp->consumer),
415 	    ("g_destroy_geom(%s) with consumer(s) [%p]",
416 	    gp->name, LIST_FIRST(&gp->consumer)));
417 	KASSERT(LIST_EMPTY(&gp->provider),
418 	    ("g_destroy_geom(%s) with provider(s) [%p]",
419 	    gp->name, LIST_FIRST(&gp->provider)));
420 	g_cancel_event(gp);
421 	LIST_REMOVE(gp, geom);
422 	TAILQ_REMOVE(&geoms, gp, geoms);
423 	g_free(gp->name);
424 	g_free(gp);
425 }
426 
427 /*
428  * This function is called (repeatedly) until the geom has withered away.
429  */
430 void
431 g_wither_geom(struct g_geom *gp, int error)
432 {
433 	struct g_provider *pp;
434 
435 	g_topology_assert();
436 	G_VALID_GEOM(gp);
437 	g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name);
438 	if (!(gp->flags & G_GEOM_WITHER)) {
439 		gp->flags |= G_GEOM_WITHER;
440 		LIST_FOREACH(pp, &gp->provider, provider)
441 			if (!(pp->flags & G_PF_ORPHAN))
442 				g_orphan_provider(pp, error);
443 	}
444 	g_do_wither();
445 }
446 
447 /*
448  * Convenience function to destroy a particular provider.
449  */
450 void
451 g_wither_provider(struct g_provider *pp, int error)
452 {
453 
454 	pp->flags |= G_PF_WITHER;
455 	if (!(pp->flags & G_PF_ORPHAN))
456 		g_orphan_provider(pp, error);
457 }
458 
459 /*
460  * This function is called (repeatedly) until the has withered away.
461  */
462 void
463 g_wither_geom_close(struct g_geom *gp, int error)
464 {
465 	struct g_consumer *cp;
466 
467 	g_topology_assert();
468 	G_VALID_GEOM(gp);
469 	g_trace(G_T_TOPOLOGY, "g_wither_geom_close(%p(%s))", gp, gp->name);
470 	LIST_FOREACH(cp, &gp->consumer, consumer)
471 		if (cp->acr || cp->acw || cp->ace)
472 			g_access(cp, -cp->acr, -cp->acw, -cp->ace);
473 	g_wither_geom(gp, error);
474 }
475 
476 /*
477  * This function is called (repeatedly) until we can't wash away more
478  * withered bits at present.
479  */
480 void
481 g_wither_washer(void)
482 {
483 	struct g_class *mp;
484 	struct g_geom *gp, *gp2;
485 	struct g_provider *pp, *pp2;
486 	struct g_consumer *cp, *cp2;
487 
488 	g_topology_assert();
489 	LIST_FOREACH(mp, &g_classes, class) {
490 		LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
491 			LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
492 				if (!(pp->flags & G_PF_WITHER))
493 					continue;
494 				if (LIST_EMPTY(&pp->consumers))
495 					g_destroy_provider(pp);
496 			}
497 			if (!(gp->flags & G_GEOM_WITHER))
498 				continue;
499 			LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
500 				if (LIST_EMPTY(&pp->consumers))
501 					g_destroy_provider(pp);
502 			}
503 			LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp2) {
504 				if (cp->acr || cp->acw || cp->ace)
505 					continue;
506 				if (cp->provider != NULL)
507 					g_detach(cp);
508 				g_destroy_consumer(cp);
509 			}
510 			if (LIST_EMPTY(&gp->provider) &&
511 			    LIST_EMPTY(&gp->consumer))
512 				g_destroy_geom(gp);
513 		}
514 	}
515 }
516 
517 struct g_consumer *
518 g_new_consumer(struct g_geom *gp)
519 {
520 	struct g_consumer *cp;
521 
522 	g_topology_assert();
523 	G_VALID_GEOM(gp);
524 	KASSERT(!(gp->flags & G_GEOM_WITHER),
525 	    ("g_new_consumer on WITHERing geom(%s) (class %s)",
526 	    gp->name, gp->class->name));
527 	KASSERT(gp->orphan != NULL,
528 	    ("g_new_consumer on geom(%s) (class %s) without orphan",
529 	    gp->name, gp->class->name));
530 
531 	cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO);
532 	cp->geom = gp;
533 	cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED,
534 	    DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
535 	LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
536 	return(cp);
537 }
538 
539 void
540 g_destroy_consumer(struct g_consumer *cp)
541 {
542 	struct g_geom *gp;
543 
544 	g_topology_assert();
545 	G_VALID_CONSUMER(cp);
546 	g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
547 	KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
548 	KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
549 	KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
550 	KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
551 	g_cancel_event(cp);
552 	gp = cp->geom;
553 	LIST_REMOVE(cp, consumer);
554 	devstat_remove_entry(cp->stat);
555 	g_free(cp);
556 	if (gp->flags & G_GEOM_WITHER)
557 		g_do_wither();
558 }
559 
560 static void
561 g_new_provider_event(void *arg, int flag)
562 {
563 	struct g_class *mp;
564 	struct g_provider *pp;
565 	struct g_consumer *cp, *next_cp;
566 
567 	g_topology_assert();
568 	if (flag == EV_CANCEL)
569 		return;
570 	if (g_shutdown)
571 		return;
572 	pp = arg;
573 	G_VALID_PROVIDER(pp);
574 	if ((pp->flags & G_PF_WITHER) != 0)
575 		return;
576 	LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, next_cp) {
577 		if ((cp->flags & G_CF_ORPHAN) == 0 &&
578 		    cp->geom->attrchanged != NULL)
579 			cp->geom->attrchanged(cp, "GEOM::media");
580 	}
581 	if (g_notaste)
582 		return;
583 	LIST_FOREACH(mp, &g_classes, class) {
584 		if (mp->taste == NULL)
585 			continue;
586 		LIST_FOREACH(cp, &pp->consumers, consumers)
587 			if (cp->geom->class == mp &&
588 			    (cp->flags & G_CF_ORPHAN) == 0)
589 				break;
590 		if (cp != NULL)
591 			continue;
592 		mp->taste(mp, pp, 0);
593 		g_topology_assert();
594 	}
595 }
596 
597 struct g_provider *
598 g_new_providerf(struct g_geom *gp, const char *fmt, ...)
599 {
600 	struct g_provider *pp;
601 	struct sbuf *sb;
602 	va_list ap;
603 
604 	g_topology_assert();
605 	G_VALID_GEOM(gp);
606 	KASSERT(gp->access != NULL,
607 	    ("new provider on geom(%s) without ->access (class %s)",
608 	    gp->name, gp->class->name));
609 	KASSERT(gp->start != NULL,
610 	    ("new provider on geom(%s) without ->start (class %s)",
611 	    gp->name, gp->class->name));
612 	KASSERT(!(gp->flags & G_GEOM_WITHER),
613 	    ("new provider on WITHERing geom(%s) (class %s)",
614 	    gp->name, gp->class->name));
615 	sb = sbuf_new_auto();
616 	va_start(ap, fmt);
617 	sbuf_vprintf(sb, fmt, ap);
618 	va_end(ap);
619 	sbuf_finish(sb);
620 	pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
621 	pp->name = (char *)(pp + 1);
622 	strcpy(pp->name, sbuf_data(sb));
623 	sbuf_delete(sb);
624 	LIST_INIT(&pp->consumers);
625 	LIST_INIT(&pp->aliases);
626 	pp->error = ENXIO;
627 	pp->geom = gp;
628 	pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED,
629 	    DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
630 	LIST_INSERT_HEAD(&gp->provider, pp, provider);
631 	g_post_event(g_new_provider_event, pp, M_WAITOK, pp, gp, NULL);
632 	return (pp);
633 }
634 
635 void
636 g_provider_add_alias(struct g_provider *pp, const char *fmt, ...)
637 {
638 	struct sbuf *sb;
639 	struct g_geom_alias *gap;
640 	va_list ap;
641 
642 	/*
643 	 * Generate the alias string and save it in the list.
644 	 */
645 	sb = sbuf_new_auto();
646 	va_start(ap, fmt);
647 	sbuf_vprintf(sb, fmt, ap);
648 	va_end(ap);
649 	sbuf_finish(sb);
650 
651 	LIST_FOREACH(gap, &pp->aliases, ga_next) {
652 		if (strcmp(gap->ga_alias, sbuf_data(sb)) != 0)
653 			continue;
654 		/* Don't re-add the same alias. */
655 		sbuf_delete(sb);
656 		return;
657 	}
658 
659 	gap = g_malloc(sizeof(*gap) + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
660 	memcpy((char *)(gap + 1), sbuf_data(sb), sbuf_len(sb));
661 	sbuf_delete(sb);
662 	gap->ga_alias = (const char *)(gap + 1);
663 	LIST_INSERT_HEAD(&pp->aliases, gap, ga_next);
664 }
665 
666 void
667 g_error_provider(struct g_provider *pp, int error)
668 {
669 
670 	/* G_VALID_PROVIDER(pp);  We may not have g_topology */
671 	pp->error = error;
672 }
673 
674 static void
675 g_resize_provider_event(void *arg, int flag)
676 {
677 	struct g_hh00 *hh;
678 	struct g_class *mp;
679 	struct g_geom *gp;
680 	struct g_provider *pp;
681 	struct g_consumer *cp, *cp2;
682 	off_t size;
683 
684 	g_topology_assert();
685 	if (g_shutdown)
686 		return;
687 
688 	hh = arg;
689 	pp = hh->pp;
690 	size = hh->size;
691 	g_free(hh);
692 
693 	G_VALID_PROVIDER(pp);
694 	KASSERT(!(pp->flags & G_PF_WITHER),
695 	    ("g_resize_provider_event but withered"));
696 	g_trace(G_T_TOPOLOGY, "g_resize_provider_event(%p)", pp);
697 
698 	LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, cp2) {
699 		gp = cp->geom;
700 		if (gp->resize == NULL && size < pp->mediasize) {
701 			/*
702 			 * XXX: g_dev_orphan method does deferred destroying
703 			 * and it is possible, that other event could already
704 			 * call the orphan method. Check consumer's flags to
705 			 * do not schedule it twice.
706 			 */
707 			if (cp->flags & G_CF_ORPHAN)
708 				continue;
709 			cp->flags |= G_CF_ORPHAN;
710 			cp->geom->orphan(cp);
711 		}
712 	}
713 
714 	pp->mediasize = size;
715 
716 	LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, cp2) {
717 		gp = cp->geom;
718 		if ((gp->flags & G_GEOM_WITHER) == 0 && gp->resize != NULL)
719 			gp->resize(cp);
720 	}
721 
722 	/*
723 	 * After resizing, the previously invalid GEOM class metadata
724 	 * might become valid.  This means we should retaste.
725 	 */
726 	LIST_FOREACH(mp, &g_classes, class) {
727 		if (mp->taste == NULL)
728 			continue;
729 		LIST_FOREACH(cp, &pp->consumers, consumers)
730 			if (cp->geom->class == mp &&
731 			    (cp->flags & G_CF_ORPHAN) == 0)
732 				break;
733 		if (cp != NULL)
734 			continue;
735 		mp->taste(mp, pp, 0);
736 		g_topology_assert();
737 	}
738 }
739 
740 void
741 g_resize_provider(struct g_provider *pp, off_t size)
742 {
743 	struct g_hh00 *hh;
744 
745 	G_VALID_PROVIDER(pp);
746 	if (pp->flags & G_PF_WITHER)
747 		return;
748 
749 	if (size == pp->mediasize)
750 		return;
751 
752 	hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
753 	hh->pp = pp;
754 	hh->size = size;
755 	g_post_event(g_resize_provider_event, hh, M_WAITOK, NULL);
756 }
757 
758 struct g_provider *
759 g_provider_by_name(char const *arg)
760 {
761 	struct g_class *cp;
762 	struct g_geom *gp;
763 	struct g_provider *pp, *wpp;
764 
765 	if (strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
766 		arg += sizeof(_PATH_DEV) - 1;
767 
768 	wpp = NULL;
769 	LIST_FOREACH(cp, &g_classes, class) {
770 		LIST_FOREACH(gp, &cp->geom, geom) {
771 			LIST_FOREACH(pp, &gp->provider, provider) {
772 				if (strcmp(arg, pp->name) != 0)
773 					continue;
774 				if ((gp->flags & G_GEOM_WITHER) == 0 &&
775 				    (pp->flags & G_PF_WITHER) == 0)
776 					return (pp);
777 				else
778 					wpp = pp;
779 			}
780 		}
781 	}
782 
783 	return (wpp);
784 }
785 
786 void
787 g_destroy_provider(struct g_provider *pp)
788 {
789 	struct g_geom *gp;
790 	struct g_geom_alias *gap, *gaptmp;
791 
792 	g_topology_assert();
793 	G_VALID_PROVIDER(pp);
794 	KASSERT(LIST_EMPTY(&pp->consumers),
795 	    ("g_destroy_provider but attached"));
796 	KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
797 	KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
798 	KASSERT (pp->ace == 0, ("g_destroy_provider with ace"));
799 	g_cancel_event(pp);
800 	LIST_REMOVE(pp, provider);
801 	gp = pp->geom;
802 	devstat_remove_entry(pp->stat);
803 	/*
804 	 * If a callback was provided, send notification that the provider
805 	 * is now gone.
806 	 */
807 	if (gp->providergone != NULL)
808 		gp->providergone(pp);
809 	LIST_FOREACH_SAFE(gap, &pp->aliases, ga_next, gaptmp)
810 		g_free(gap);
811 	g_free(pp);
812 	if ((gp->flags & G_GEOM_WITHER))
813 		g_do_wither();
814 }
815 
816 /*
817  * We keep the "geoms" list sorted by topological order (== increasing
818  * numerical rank) at all times.
819  * When an attach is done, the attaching geoms rank is invalidated
820  * and it is moved to the tail of the list.
821  * All geoms later in the sequence has their ranks reevaluated in
822  * sequence.  If we cannot assign rank to a geom because it's
823  * prerequisites do not have rank, we move that element to the tail
824  * of the sequence with invalid rank as well.
825  * At some point we encounter our original geom and if we stil fail
826  * to assign it a rank, there must be a loop and we fail back to
827  * g_attach() which detach again and calls redo_rank again
828  * to fix up the damage.
829  * It would be much simpler code wise to do it recursively, but we
830  * can't risk that on the kernel stack.
831  */
832 
833 static int
834 redo_rank(struct g_geom *gp)
835 {
836 	struct g_consumer *cp;
837 	struct g_geom *gp1, *gp2;
838 	int n, m;
839 
840 	g_topology_assert();
841 	G_VALID_GEOM(gp);
842 
843 	/* Invalidate this geoms rank and move it to the tail */
844 	gp1 = TAILQ_NEXT(gp, geoms);
845 	if (gp1 != NULL) {
846 		gp->rank = 0;
847 		TAILQ_REMOVE(&geoms, gp, geoms);
848 		TAILQ_INSERT_TAIL(&geoms, gp, geoms);
849 	} else {
850 		gp1 = gp;
851 	}
852 
853 	/* re-rank the rest of the sequence */
854 	for (; gp1 != NULL; gp1 = gp2) {
855 		gp1->rank = 0;
856 		m = 1;
857 		LIST_FOREACH(cp, &gp1->consumer, consumer) {
858 			if (cp->provider == NULL)
859 				continue;
860 			n = cp->provider->geom->rank;
861 			if (n == 0) {
862 				m = 0;
863 				break;
864 			} else if (n >= m)
865 				m = n + 1;
866 		}
867 		gp1->rank = m;
868 		gp2 = TAILQ_NEXT(gp1, geoms);
869 
870 		/* got a rank, moving on */
871 		if (m != 0)
872 			continue;
873 
874 		/* no rank to original geom means loop */
875 		if (gp == gp1)
876 			return (ELOOP);
877 
878 		/* no rank, put it at the end move on */
879 		TAILQ_REMOVE(&geoms, gp1, geoms);
880 		TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
881 	}
882 	return (0);
883 }
884 
885 int
886 g_attach(struct g_consumer *cp, struct g_provider *pp)
887 {
888 	int error;
889 
890 	g_topology_assert();
891 	G_VALID_CONSUMER(cp);
892 	G_VALID_PROVIDER(pp);
893 	g_trace(G_T_TOPOLOGY, "g_attach(%p, %p)", cp, pp);
894 	KASSERT(cp->provider == NULL, ("attach but attached"));
895 	if ((pp->flags & (G_PF_ORPHAN | G_PF_WITHER)) != 0)
896 		return (ENXIO);
897 	cp->provider = pp;
898 	cp->flags &= ~G_CF_ORPHAN;
899 	LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
900 	error = redo_rank(cp->geom);
901 	if (error) {
902 		LIST_REMOVE(cp, consumers);
903 		cp->provider = NULL;
904 		redo_rank(cp->geom);
905 	}
906 	return (error);
907 }
908 
909 void
910 g_detach(struct g_consumer *cp)
911 {
912 	struct g_provider *pp;
913 
914 	g_topology_assert();
915 	G_VALID_CONSUMER(cp);
916 	g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp);
917 	KASSERT(cp->provider != NULL, ("detach but not attached"));
918 	KASSERT(cp->acr == 0, ("detach but nonzero acr"));
919 	KASSERT(cp->acw == 0, ("detach but nonzero acw"));
920 	KASSERT(cp->ace == 0, ("detach but nonzero ace"));
921 	KASSERT(cp->nstart == cp->nend,
922 	    ("detach with active requests"));
923 	pp = cp->provider;
924 	LIST_REMOVE(cp, consumers);
925 	cp->provider = NULL;
926 	if ((cp->geom->flags & G_GEOM_WITHER) ||
927 	    (pp->geom->flags & G_GEOM_WITHER) ||
928 	    (pp->flags & G_PF_WITHER))
929 		g_do_wither();
930 	redo_rank(cp->geom);
931 }
932 
933 /*
934  * g_access()
935  *
936  * Access-check with delta values.  The question asked is "can provider
937  * "cp" change the access counters by the relative amounts dc[rwe] ?"
938  */
939 
940 int
941 g_access(struct g_consumer *cp, int dcr, int dcw, int dce)
942 {
943 	struct g_provider *pp;
944 	struct g_geom *gp;
945 	int pw, pe;
946 #ifdef INVARIANTS
947 	int sr, sw, se;
948 #endif
949 	int error;
950 
951 	g_topology_assert();
952 	G_VALID_CONSUMER(cp);
953 	pp = cp->provider;
954 	KASSERT(pp != NULL, ("access but not attached"));
955 	G_VALID_PROVIDER(pp);
956 	gp = pp->geom;
957 
958 	g_trace(G_T_ACCESS, "g_access(%p(%s), %d, %d, %d)",
959 	    cp, pp->name, dcr, dcw, dce);
960 
961 	KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
962 	KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
963 	KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
964 	KASSERT(dcr != 0 || dcw != 0 || dce != 0, ("NOP access request"));
965 	KASSERT(cp->acr + dcr != 0 || cp->acw + dcw != 0 ||
966 	    cp->ace + dce != 0 || cp->nstart == cp->nend,
967 	    ("Last close with active requests"));
968 	KASSERT(gp->access != NULL, ("NULL geom->access"));
969 
970 	/*
971 	 * If our class cares about being spoiled, and we have been, we
972 	 * are probably just ahead of the event telling us that.  Fail
973 	 * now rather than having to unravel this later.
974 	 */
975 	if (cp->geom->spoiled != NULL && (cp->flags & G_CF_SPOILED) &&
976 	    (dcr > 0 || dcw > 0 || dce > 0))
977 		return (ENXIO);
978 
979 	/*
980 	 * A number of GEOM classes either need to perform an I/O on the first
981 	 * open or to acquire a different subsystem's lock.  To do that they
982 	 * may have to drop the topology lock.
983 	 * Other GEOM classes perform special actions when opening a lower rank
984 	 * geom for the first time.  As a result, more than one thread may
985 	 * end up performing the special actions.
986 	 * So, we prevent concurrent "first" opens by marking the consumer with
987 	 * special flag.
988 	 *
989 	 * Note that if the geom's access method never drops the topology lock,
990 	 * then we will never see G_GEOM_IN_ACCESS here.
991 	 */
992 	while ((gp->flags & G_GEOM_IN_ACCESS) != 0) {
993 		g_trace(G_T_ACCESS,
994 		    "%s: race on geom %s via provider %s and consumer of %s",
995 		    __func__, gp->name, pp->name, cp->geom->name);
996 		gp->flags |= G_GEOM_ACCESS_WAIT;
997 		g_topology_sleep(gp, 0);
998 	}
999 
1000 	/*
1001 	 * Figure out what counts the provider would have had, if this
1002 	 * consumer had (r0w0e0) at this time.
1003 	 */
1004 	pw = pp->acw - cp->acw;
1005 	pe = pp->ace - cp->ace;
1006 
1007 	g_trace(G_T_ACCESS,
1008     "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
1009 	    dcr, dcw, dce,
1010 	    cp->acr, cp->acw, cp->ace,
1011 	    pp->acr, pp->acw, pp->ace,
1012 	    pp, pp->name);
1013 
1014 	/* If foot-shooting is enabled, any open on rank#1 is OK */
1015 	if ((g_debugflags & G_F_FOOTSHOOTING) && gp->rank == 1)
1016 		;
1017 	/* If we try exclusive but already write: fail */
1018 	else if (dce > 0 && pw > 0)
1019 		return (EPERM);
1020 	/* If we try write but already exclusive: fail */
1021 	else if (dcw > 0 && pe > 0)
1022 		return (EPERM);
1023 	/* If we try to open more but provider is error'ed: fail */
1024 	else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0) {
1025 		printf("%s(%d): provider %s has error %d set\n",
1026 		    __func__, __LINE__, pp->name, pp->error);
1027 		return (pp->error);
1028 	}
1029 
1030 	/* Ok then... */
1031 
1032 #ifdef INVARIANTS
1033 	sr = cp->acr;
1034 	sw = cp->acw;
1035 	se = cp->ace;
1036 #endif
1037 	gp->flags |= G_GEOM_IN_ACCESS;
1038 	error = gp->access(pp, dcr, dcw, dce);
1039 	KASSERT(dcr > 0 || dcw > 0 || dce > 0 || error == 0,
1040 	    ("Geom provider %s::%s dcr=%d dcw=%d dce=%d error=%d failed "
1041 	    "closing ->access()", gp->class->name, pp->name, dcr, dcw,
1042 	    dce, error));
1043 
1044 	g_topology_assert();
1045 	gp->flags &= ~G_GEOM_IN_ACCESS;
1046 	KASSERT(cp->acr == sr && cp->acw == sw && cp->ace == se,
1047 	    ("Access counts changed during geom->access"));
1048 	if ((gp->flags & G_GEOM_ACCESS_WAIT) != 0) {
1049 		gp->flags &= ~G_GEOM_ACCESS_WAIT;
1050 		wakeup(gp);
1051 	}
1052 
1053 	if (!error) {
1054 		/*
1055 		 * If we open first write, spoil any partner consumers.
1056 		 * If we close last write and provider is not errored,
1057 		 * trigger re-taste.
1058 		 */
1059 		if (pp->acw == 0 && dcw != 0)
1060 			g_spoil(pp, cp);
1061 		else if (pp->acw != 0 && pp->acw == -dcw && pp->error == 0 &&
1062 		    !(gp->flags & G_GEOM_WITHER))
1063 			g_post_event(g_new_provider_event, pp, M_WAITOK,
1064 			    pp, NULL);
1065 
1066 		pp->acr += dcr;
1067 		pp->acw += dcw;
1068 		pp->ace += dce;
1069 		cp->acr += dcr;
1070 		cp->acw += dcw;
1071 		cp->ace += dce;
1072 		if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)
1073 			KASSERT(pp->sectorsize > 0,
1074 			    ("Provider %s lacks sectorsize", pp->name));
1075 		if ((cp->geom->flags & G_GEOM_WITHER) &&
1076 		    cp->acr == 0 && cp->acw == 0 && cp->ace == 0)
1077 			g_do_wither();
1078 	}
1079 	return (error);
1080 }
1081 
1082 int
1083 g_handleattr_int(struct bio *bp, const char *attribute, int val)
1084 {
1085 
1086 	return (g_handleattr(bp, attribute, &val, sizeof val));
1087 }
1088 
1089 int
1090 g_handleattr_uint16_t(struct bio *bp, const char *attribute, uint16_t val)
1091 {
1092 
1093 	return (g_handleattr(bp, attribute, &val, sizeof val));
1094 }
1095 
1096 int
1097 g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val)
1098 {
1099 
1100 	return (g_handleattr(bp, attribute, &val, sizeof val));
1101 }
1102 
1103 int
1104 g_handleattr_str(struct bio *bp, const char *attribute, const char *str)
1105 {
1106 
1107 	return (g_handleattr(bp, attribute, str, 0));
1108 }
1109 
1110 int
1111 g_handleattr(struct bio *bp, const char *attribute, const void *val, int len)
1112 {
1113 	int error = 0;
1114 
1115 	if (strcmp(bp->bio_attribute, attribute))
1116 		return (0);
1117 	if (len == 0) {
1118 		bzero(bp->bio_data, bp->bio_length);
1119 		if (strlcpy(bp->bio_data, val, bp->bio_length) >=
1120 		    bp->bio_length) {
1121 			printf("%s: %s %s bio_length %jd strlen %zu -> EFAULT\n",
1122 			    __func__, bp->bio_to->name, attribute,
1123 			    (intmax_t)bp->bio_length, strlen(val));
1124 			error = EFAULT;
1125 		}
1126 	} else if (bp->bio_length == len) {
1127 		bcopy(val, bp->bio_data, len);
1128 	} else {
1129 		printf("%s: %s %s bio_length %jd len %d -> EFAULT\n", __func__,
1130 		    bp->bio_to->name, attribute, (intmax_t)bp->bio_length, len);
1131 		error = EFAULT;
1132 	}
1133 	if (error == 0)
1134 		bp->bio_completed = bp->bio_length;
1135 	g_io_deliver(bp, error);
1136 	return (1);
1137 }
1138 
1139 int
1140 g_std_access(struct g_provider *pp,
1141 	int dr __unused, int dw __unused, int de __unused)
1142 {
1143 
1144 	g_topology_assert();
1145 	G_VALID_PROVIDER(pp);
1146         return (0);
1147 }
1148 
1149 void
1150 g_std_done(struct bio *bp)
1151 {
1152 	struct bio *bp2;
1153 
1154 	bp2 = bp->bio_parent;
1155 	if (bp2->bio_error == 0)
1156 		bp2->bio_error = bp->bio_error;
1157 	bp2->bio_completed += bp->bio_completed;
1158 	g_destroy_bio(bp);
1159 	bp2->bio_inbed++;
1160 	if (bp2->bio_children == bp2->bio_inbed) {
1161 		if (bp2->bio_cmd == BIO_SPEEDUP)
1162 			bp2->bio_completed = bp2->bio_length;
1163 		g_io_deliver(bp2, bp2->bio_error);
1164 	}
1165 }
1166 
1167 /* XXX: maybe this is only g_slice_spoiled */
1168 
1169 void
1170 g_std_spoiled(struct g_consumer *cp)
1171 {
1172 	struct g_geom *gp;
1173 	struct g_provider *pp;
1174 
1175 	g_topology_assert();
1176 	G_VALID_CONSUMER(cp);
1177 	g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
1178 	cp->flags |= G_CF_ORPHAN;
1179 	g_detach(cp);
1180 	gp = cp->geom;
1181 	LIST_FOREACH(pp, &gp->provider, provider)
1182 		g_orphan_provider(pp, ENXIO);
1183 	g_destroy_consumer(cp);
1184 	if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
1185 		g_destroy_geom(gp);
1186 	else
1187 		gp->flags |= G_GEOM_WITHER;
1188 }
1189 
1190 /*
1191  * Spoiling happens when a provider is opened for writing, but consumers
1192  * which are configured by in-band data are attached (slicers for instance).
1193  * Since the write might potentially change the in-band data, such consumers
1194  * need to re-evaluate their existence after the writing session closes.
1195  * We do this by (offering to) tear them down when the open for write happens
1196  * in return for a re-taste when it closes again.
1197  * Together with the fact that such consumers grab an 'e' bit whenever they
1198  * are open, regardless of mode, this ends up DTRT.
1199  */
1200 
1201 static void
1202 g_spoil_event(void *arg, int flag)
1203 {
1204 	struct g_provider *pp;
1205 	struct g_consumer *cp, *cp2;
1206 
1207 	g_topology_assert();
1208 	if (flag == EV_CANCEL)
1209 		return;
1210 	pp = arg;
1211 	G_VALID_PROVIDER(pp);
1212 	g_trace(G_T_TOPOLOGY, "%s %p(%s:%s:%s)", __func__, pp,
1213 	    pp->geom->class->name, pp->geom->name, pp->name);
1214 	for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) {
1215 		cp2 = LIST_NEXT(cp, consumers);
1216 		if ((cp->flags & G_CF_SPOILED) == 0)
1217 			continue;
1218 		cp->flags &= ~G_CF_SPOILED;
1219 		if (cp->geom->spoiled == NULL)
1220 			continue;
1221 		cp->geom->spoiled(cp);
1222 		g_topology_assert();
1223 	}
1224 }
1225 
1226 void
1227 g_spoil(struct g_provider *pp, struct g_consumer *cp)
1228 {
1229 	struct g_consumer *cp2;
1230 
1231 	g_topology_assert();
1232 	G_VALID_PROVIDER(pp);
1233 	G_VALID_CONSUMER(cp);
1234 
1235 	LIST_FOREACH(cp2, &pp->consumers, consumers) {
1236 		if (cp2 == cp)
1237 			continue;
1238 /*
1239 		KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
1240 		KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
1241 */
1242 		KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
1243 		cp2->flags |= G_CF_SPOILED;
1244 	}
1245 	g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL);
1246 }
1247 
1248 static void
1249 g_media_changed_event(void *arg, int flag)
1250 {
1251 	struct g_provider *pp;
1252 	int retaste;
1253 
1254 	g_topology_assert();
1255 	if (flag == EV_CANCEL)
1256 		return;
1257 	pp = arg;
1258 	G_VALID_PROVIDER(pp);
1259 
1260 	/*
1261 	 * If provider was not open for writing, queue retaste after spoiling.
1262 	 * If it was, retaste will happen automatically on close.
1263 	 */
1264 	retaste = (pp->acw == 0 && pp->error == 0 &&
1265 	    !(pp->geom->flags & G_GEOM_WITHER));
1266 	g_spoil_event(arg, flag);
1267 	if (retaste)
1268 		g_post_event(g_new_provider_event, pp, M_WAITOK, pp, NULL);
1269 }
1270 
1271 int
1272 g_media_changed(struct g_provider *pp, int flag)
1273 {
1274 	struct g_consumer *cp;
1275 
1276 	LIST_FOREACH(cp, &pp->consumers, consumers)
1277 		cp->flags |= G_CF_SPOILED;
1278 	return (g_post_event(g_media_changed_event, pp, flag, pp, NULL));
1279 }
1280 
1281 int
1282 g_media_gone(struct g_provider *pp, int flag)
1283 {
1284 	struct g_consumer *cp;
1285 
1286 	LIST_FOREACH(cp, &pp->consumers, consumers)
1287 		cp->flags |= G_CF_SPOILED;
1288 	return (g_post_event(g_spoil_event, pp, flag, pp, NULL));
1289 }
1290 
1291 int
1292 g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len)
1293 {
1294 	int error, i;
1295 
1296 	i = len;
1297 	error = g_io_getattr(attr, cp, &i, var);
1298 	if (error)
1299 		return (error);
1300 	if (i != len)
1301 		return (EINVAL);
1302 	return (0);
1303 }
1304 
1305 static int
1306 g_get_device_prefix_len(const char *name)
1307 {
1308 	int len;
1309 
1310 	if (strncmp(name, "ada", 3) == 0)
1311 		len = 3;
1312 	else if (strncmp(name, "ad", 2) == 0)
1313 		len = 2;
1314 	else
1315 		return (0);
1316 	if (name[len] < '0' || name[len] > '9')
1317 		return (0);
1318 	do {
1319 		len++;
1320 	} while (name[len] >= '0' && name[len] <= '9');
1321 	return (len);
1322 }
1323 
1324 int
1325 g_compare_names(const char *namea, const char *nameb)
1326 {
1327 	int deva, devb;
1328 
1329 	if (strcmp(namea, nameb) == 0)
1330 		return (1);
1331 	deva = g_get_device_prefix_len(namea);
1332 	if (deva == 0)
1333 		return (0);
1334 	devb = g_get_device_prefix_len(nameb);
1335 	if (devb == 0)
1336 		return (0);
1337 	if (strcmp(namea + deva, nameb + devb) == 0)
1338 		return (1);
1339 	return (0);
1340 }
1341 
1342 #if defined(DIAGNOSTIC) || defined(DDB)
1343 /*
1344  * This function walks the mesh and returns a non-zero integer if it
1345  * finds the argument pointer is an object. The return value indicates
1346  * which type of object it is believed to be. If topology is not locked,
1347  * this function is potentially dangerous, but we don't assert that the
1348  * topology lock is held when called from debugger.
1349  */
1350 int
1351 g_valid_obj(void const *ptr)
1352 {
1353 	struct g_class *mp;
1354 	struct g_geom *gp;
1355 	struct g_consumer *cp;
1356 	struct g_provider *pp;
1357 
1358 #ifdef KDB
1359 	if (kdb_active == 0)
1360 #endif
1361 		g_topology_assert();
1362 
1363 	LIST_FOREACH(mp, &g_classes, class) {
1364 		if (ptr == mp)
1365 			return (1);
1366 		LIST_FOREACH(gp, &mp->geom, geom) {
1367 			if (ptr == gp)
1368 				return (2);
1369 			LIST_FOREACH(cp, &gp->consumer, consumer)
1370 				if (ptr == cp)
1371 					return (3);
1372 			LIST_FOREACH(pp, &gp->provider, provider)
1373 				if (ptr == pp)
1374 					return (4);
1375 		}
1376 	}
1377 	return(0);
1378 }
1379 #endif
1380 
1381 #ifdef DDB
1382 
1383 #define	gprintf(...)	do {						\
1384 	db_printf("%*s", indent, "");					\
1385 	db_printf(__VA_ARGS__);						\
1386 } while (0)
1387 #define	gprintln(...)	do {						\
1388 	gprintf(__VA_ARGS__);						\
1389 	db_printf("\n");						\
1390 } while (0)
1391 
1392 #define	ADDFLAG(obj, flag, sflag)	do {				\
1393 	if ((obj)->flags & (flag)) {					\
1394 		if (comma)						\
1395 			strlcat(str, ",", size);			\
1396 		strlcat(str, (sflag), size);				\
1397 		comma = 1;						\
1398 	}								\
1399 } while (0)
1400 
1401 static char *
1402 provider_flags_to_string(struct g_provider *pp, char *str, size_t size)
1403 {
1404 	int comma = 0;
1405 
1406 	bzero(str, size);
1407 	if (pp->flags == 0) {
1408 		strlcpy(str, "NONE", size);
1409 		return (str);
1410 	}
1411 	ADDFLAG(pp, G_PF_WITHER, "G_PF_WITHER");
1412 	ADDFLAG(pp, G_PF_ORPHAN, "G_PF_ORPHAN");
1413 	return (str);
1414 }
1415 
1416 static char *
1417 geom_flags_to_string(struct g_geom *gp, char *str, size_t size)
1418 {
1419 	int comma = 0;
1420 
1421 	bzero(str, size);
1422 	if (gp->flags == 0) {
1423 		strlcpy(str, "NONE", size);
1424 		return (str);
1425 	}
1426 	ADDFLAG(gp, G_GEOM_WITHER, "G_GEOM_WITHER");
1427 	return (str);
1428 }
1429 static void
1430 db_show_geom_consumer(int indent, struct g_consumer *cp)
1431 {
1432 
1433 	if (indent == 0) {
1434 		gprintln("consumer: %p", cp);
1435 		gprintln("  class:    %s (%p)", cp->geom->class->name,
1436 		    cp->geom->class);
1437 		gprintln("  geom:     %s (%p)", cp->geom->name, cp->geom);
1438 		if (cp->provider == NULL)
1439 			gprintln("  provider: none");
1440 		else {
1441 			gprintln("  provider: %s (%p)", cp->provider->name,
1442 			    cp->provider);
1443 		}
1444 		gprintln("  access:   r%dw%de%d", cp->acr, cp->acw, cp->ace);
1445 		gprintln("  flags:    0x%04x", cp->flags);
1446 #ifdef INVARIANTS
1447 		gprintln("  nstart:   %u", cp->nstart);
1448 		gprintln("  nend:     %u", cp->nend);
1449 #endif
1450 	} else {
1451 		gprintf("consumer: %p (%s), access=r%dw%de%d", cp,
1452 		    cp->provider != NULL ? cp->provider->name : "none",
1453 		    cp->acr, cp->acw, cp->ace);
1454 		if (cp->flags)
1455 			db_printf(", flags=0x%04x", cp->flags);
1456 		db_printf("\n");
1457 	}
1458 }
1459 
1460 static void
1461 db_show_geom_provider(int indent, struct g_provider *pp)
1462 {
1463 	struct g_consumer *cp;
1464 	char flags[64];
1465 
1466 	if (indent == 0) {
1467 		gprintln("provider: %s (%p)", pp->name, pp);
1468 		gprintln("  class:        %s (%p)", pp->geom->class->name,
1469 		    pp->geom->class);
1470 		gprintln("  geom:         %s (%p)", pp->geom->name, pp->geom);
1471 		gprintln("  mediasize:    %jd", (intmax_t)pp->mediasize);
1472 		gprintln("  sectorsize:   %u", pp->sectorsize);
1473 		gprintln("  stripesize:   %ju", (uintmax_t)pp->stripesize);
1474 		gprintln("  stripeoffset: %ju", (uintmax_t)pp->stripeoffset);
1475 		gprintln("  access:       r%dw%de%d", pp->acr, pp->acw,
1476 		    pp->ace);
1477 		gprintln("  flags:        %s (0x%04x)",
1478 		    provider_flags_to_string(pp, flags, sizeof(flags)),
1479 		    pp->flags);
1480 		gprintln("  error:        %d", pp->error);
1481 		if (LIST_EMPTY(&pp->consumers))
1482 			gprintln("  consumers:    none");
1483 	} else {
1484 		gprintf("provider: %s (%p), access=r%dw%de%d",
1485 		    pp->name, pp, pp->acr, pp->acw, pp->ace);
1486 		if (pp->flags != 0) {
1487 			db_printf(", flags=%s (0x%04x)",
1488 			    provider_flags_to_string(pp, flags, sizeof(flags)),
1489 			    pp->flags);
1490 		}
1491 		db_printf("\n");
1492 	}
1493 	if (!LIST_EMPTY(&pp->consumers)) {
1494 		LIST_FOREACH(cp, &pp->consumers, consumers) {
1495 			db_show_geom_consumer(indent + 2, cp);
1496 			if (db_pager_quit)
1497 				break;
1498 		}
1499 	}
1500 }
1501 
1502 static void
1503 db_show_geom_geom(int indent, struct g_geom *gp)
1504 {
1505 	struct g_provider *pp;
1506 	struct g_consumer *cp;
1507 	char flags[64];
1508 
1509 	if (indent == 0) {
1510 		gprintln("geom: %s (%p)", gp->name, gp);
1511 		gprintln("  class:     %s (%p)", gp->class->name, gp->class);
1512 		gprintln("  flags:     %s (0x%04x)",
1513 		    geom_flags_to_string(gp, flags, sizeof(flags)), gp->flags);
1514 		gprintln("  rank:      %d", gp->rank);
1515 		if (LIST_EMPTY(&gp->provider))
1516 			gprintln("  providers: none");
1517 		if (LIST_EMPTY(&gp->consumer))
1518 			gprintln("  consumers: none");
1519 	} else {
1520 		gprintf("geom: %s (%p), rank=%d", gp->name, gp, gp->rank);
1521 		if (gp->flags != 0) {
1522 			db_printf(", flags=%s (0x%04x)",
1523 			    geom_flags_to_string(gp, flags, sizeof(flags)),
1524 			    gp->flags);
1525 		}
1526 		db_printf("\n");
1527 	}
1528 	if (!LIST_EMPTY(&gp->provider)) {
1529 		LIST_FOREACH(pp, &gp->provider, provider) {
1530 			db_show_geom_provider(indent + 2, pp);
1531 			if (db_pager_quit)
1532 				break;
1533 		}
1534 	}
1535 	if (!LIST_EMPTY(&gp->consumer)) {
1536 		LIST_FOREACH(cp, &gp->consumer, consumer) {
1537 			db_show_geom_consumer(indent + 2, cp);
1538 			if (db_pager_quit)
1539 				break;
1540 		}
1541 	}
1542 }
1543 
1544 static void
1545 db_show_geom_class(struct g_class *mp)
1546 {
1547 	struct g_geom *gp;
1548 
1549 	db_printf("class: %s (%p)\n", mp->name, mp);
1550 	LIST_FOREACH(gp, &mp->geom, geom) {
1551 		db_show_geom_geom(2, gp);
1552 		if (db_pager_quit)
1553 			break;
1554 	}
1555 }
1556 
1557 /*
1558  * Print the GEOM topology or the given object.
1559  */
1560 DB_SHOW_COMMAND(geom, db_show_geom)
1561 {
1562 	struct g_class *mp;
1563 
1564 	if (!have_addr) {
1565 		/* No address given, print the entire topology. */
1566 		LIST_FOREACH(mp, &g_classes, class) {
1567 			db_show_geom_class(mp);
1568 			db_printf("\n");
1569 			if (db_pager_quit)
1570 				break;
1571 		}
1572 	} else {
1573 		switch (g_valid_obj((void *)addr)) {
1574 		case 1:
1575 			db_show_geom_class((struct g_class *)addr);
1576 			break;
1577 		case 2:
1578 			db_show_geom_geom(0, (struct g_geom *)addr);
1579 			break;
1580 		case 3:
1581 			db_show_geom_consumer(0, (struct g_consumer *)addr);
1582 			break;
1583 		case 4:
1584 			db_show_geom_provider(0, (struct g_provider *)addr);
1585 			break;
1586 		default:
1587 			db_printf("Not a GEOM object.\n");
1588 			break;
1589 		}
1590 	}
1591 }
1592 
1593 static void
1594 db_print_bio_cmd(struct bio *bp)
1595 {
1596 	db_printf("  cmd: ");
1597 	switch (bp->bio_cmd) {
1598 	case BIO_READ: db_printf("BIO_READ"); break;
1599 	case BIO_WRITE: db_printf("BIO_WRITE"); break;
1600 	case BIO_DELETE: db_printf("BIO_DELETE"); break;
1601 	case BIO_GETATTR: db_printf("BIO_GETATTR"); break;
1602 	case BIO_FLUSH: db_printf("BIO_FLUSH"); break;
1603 	case BIO_CMD0: db_printf("BIO_CMD0"); break;
1604 	case BIO_CMD1: db_printf("BIO_CMD1"); break;
1605 	case BIO_CMD2: db_printf("BIO_CMD2"); break;
1606 	case BIO_ZONE: db_printf("BIO_ZONE"); break;
1607 	default: db_printf("UNKNOWN"); break;
1608 	}
1609 	db_printf("\n");
1610 }
1611 
1612 static void
1613 db_print_bio_flags(struct bio *bp)
1614 {
1615 	int comma;
1616 
1617 	comma = 0;
1618 	db_printf("  flags: ");
1619 	if (bp->bio_flags & BIO_ERROR) {
1620 		db_printf("BIO_ERROR");
1621 		comma = 1;
1622 	}
1623 	if (bp->bio_flags & BIO_DONE) {
1624 		db_printf("%sBIO_DONE", (comma ? ", " : ""));
1625 		comma = 1;
1626 	}
1627 	if (bp->bio_flags & BIO_ONQUEUE)
1628 		db_printf("%sBIO_ONQUEUE", (comma ? ", " : ""));
1629 	db_printf("\n");
1630 }
1631 
1632 /*
1633  * Print useful information in a BIO
1634  */
1635 DB_SHOW_COMMAND(bio, db_show_bio)
1636 {
1637 	struct bio *bp;
1638 
1639 	if (have_addr) {
1640 		bp = (struct bio *)addr;
1641 		db_printf("BIO %p\n", bp);
1642 		db_print_bio_cmd(bp);
1643 		db_print_bio_flags(bp);
1644 		db_printf("  cflags: 0x%hx\n", bp->bio_cflags);
1645 		db_printf("  pflags: 0x%hx\n", bp->bio_pflags);
1646 		db_printf("  offset: %jd\n", (intmax_t)bp->bio_offset);
1647 		db_printf("  length: %jd\n", (intmax_t)bp->bio_length);
1648 		db_printf("  bcount: %ld\n", bp->bio_bcount);
1649 		db_printf("  resid: %ld\n", bp->bio_resid);
1650 		db_printf("  completed: %jd\n", (intmax_t)bp->bio_completed);
1651 		db_printf("  children: %u\n", bp->bio_children);
1652 		db_printf("  inbed: %u\n", bp->bio_inbed);
1653 		db_printf("  error: %d\n", bp->bio_error);
1654 		db_printf("  parent: %p\n", bp->bio_parent);
1655 		db_printf("  driver1: %p\n", bp->bio_driver1);
1656 		db_printf("  driver2: %p\n", bp->bio_driver2);
1657 		db_printf("  caller1: %p\n", bp->bio_caller1);
1658 		db_printf("  caller2: %p\n", bp->bio_caller2);
1659 		db_printf("  bio_from: %p\n", bp->bio_from);
1660 		db_printf("  bio_to: %p\n", bp->bio_to);
1661 
1662 #if defined(BUF_TRACKING) || defined(FULL_BUF_TRACKING)
1663 		db_printf("  bio_track_bp: %p\n", bp->bio_track_bp);
1664 #endif
1665 	}
1666 }
1667 
1668 #undef	gprintf
1669 #undef	gprintln
1670 #undef	ADDFLAG
1671 
1672 #endif	/* DDB */
1673