xref: /freebsd/sys/geom/geom_subr.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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 __FBSDID("$FreeBSD$");
40 
41 #include "opt_ddb.h"
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/devicestat.h>
46 #include <sys/kernel.h>
47 #include <sys/malloc.h>
48 #include <sys/bio.h>
49 #include <sys/sysctl.h>
50 #include <sys/proc.h>
51 #include <sys/kthread.h>
52 #include <sys/lock.h>
53 #include <sys/mutex.h>
54 #include <sys/errno.h>
55 #include <sys/sbuf.h>
56 #include <sys/sdt.h>
57 #include <geom/geom.h>
58 #include <geom/geom_dbg.h>
59 #include <geom/geom_int.h>
60 #include <machine/stdarg.h>
61 
62 #ifdef DDB
63 #include <ddb/ddb.h>
64 #endif
65 
66 #ifdef KDB
67 #include <sys/kdb.h>
68 #endif
69 
70 SDT_PROVIDER_DEFINE(geom);
71 
72 struct class_list_head g_classes = LIST_HEAD_INITIALIZER(g_classes);
73 static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms);
74 char *g_wait_event, *g_wait_up, *g_wait_down, *g_wait_sim;
75 
76 struct g_hh00 {
77 	struct g_class		*mp;
78 	struct g_provider	*pp;
79 	off_t			size;
80 	int			error;
81 	int			post;
82 };
83 
84 void
85 g_dbg_printf(const char *classname, int lvl, struct bio *bp,
86     const char *format,
87     ...)
88 {
89 #ifndef PRINTF_BUFR_SIZE
90 #define PRINTF_BUFR_SIZE 64
91 #endif
92 	char bufr[PRINTF_BUFR_SIZE];
93 	struct sbuf sb, *sbp __unused;
94 	va_list ap;
95 
96 	sbp = sbuf_new(&sb, bufr, sizeof(bufr), SBUF_FIXEDLEN);
97 	KASSERT(sbp != NULL, ("sbuf_new misused?"));
98 
99 	sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
100 
101 	sbuf_cat(&sb, classname);
102 	if (lvl >= 0)
103 		sbuf_printf(&sb, "[%d]", lvl);
104 
105 	va_start(ap, format);
106 	sbuf_vprintf(&sb, format, ap);
107 	va_end(ap);
108 
109 	if (bp != NULL) {
110 		sbuf_putc(&sb, ' ');
111 		g_format_bio(&sb, bp);
112 	}
113 
114 	/* Terminate the debug line with a single '\n'. */
115 	sbuf_nl_terminate(&sb);
116 
117 	/* Flush line to printf. */
118 	sbuf_finish(&sb);
119 	sbuf_delete(&sb);
120 }
121 
122 /*
123  * This event offers a new class a chance to taste all preexisting providers.
124  */
125 static void
126 g_load_class(void *arg, int flag)
127 {
128 	struct g_hh00 *hh;
129 	struct g_class *mp2, *mp;
130 	struct g_geom *gp;
131 	struct g_provider *pp;
132 
133 	g_topology_assert();
134 	if (flag == EV_CANCEL)	/* XXX: can't happen ? */
135 		return;
136 	if (g_shutdown)
137 		return;
138 
139 	hh = arg;
140 	mp = hh->mp;
141 	hh->error = 0;
142 	if (hh->post) {
143 		g_free(hh);
144 		hh = NULL;
145 	}
146 	g_trace(G_T_TOPOLOGY, "g_load_class(%s)", mp->name);
147 	KASSERT(mp->name != NULL && *mp->name != '\0',
148 	    ("GEOM class has no name"));
149 	LIST_FOREACH(mp2, &g_classes, class) {
150 		if (mp2 == mp) {
151 			printf("The GEOM class %s is already loaded.\n",
152 			    mp2->name);
153 			if (hh != NULL)
154 				hh->error = EEXIST;
155 			return;
156 		} else if (strcmp(mp2->name, mp->name) == 0) {
157 			printf("A GEOM class %s is already loaded.\n",
158 			    mp2->name);
159 			if (hh != NULL)
160 				hh->error = EEXIST;
161 			return;
162 		}
163 	}
164 
165 	LIST_INIT(&mp->geom);
166 	LIST_INSERT_HEAD(&g_classes, mp, class);
167 	if (mp->init != NULL)
168 		mp->init(mp);
169 	if (mp->taste == NULL)
170 		return;
171 	LIST_FOREACH(mp2, &g_classes, class) {
172 		if (mp == mp2)
173 			continue;
174 		LIST_FOREACH(gp, &mp2->geom, geom) {
175 			LIST_FOREACH(pp, &gp->provider, provider) {
176 				mp->taste(mp, pp, 0);
177 				g_topology_assert();
178 			}
179 		}
180 	}
181 }
182 
183 static int
184 g_unload_class(struct g_class *mp)
185 {
186 	struct g_geom *gp;
187 	struct g_provider *pp;
188 	struct g_consumer *cp;
189 	int error;
190 
191 	g_topology_lock();
192 	g_trace(G_T_TOPOLOGY, "g_unload_class(%s)", mp->name);
193 retry:
194 	G_VALID_CLASS(mp);
195 	LIST_FOREACH(gp, &mp->geom, geom) {
196 		/* We refuse to unload if anything is open */
197 		LIST_FOREACH(pp, &gp->provider, provider)
198 			if (pp->acr || pp->acw || pp->ace) {
199 				g_topology_unlock();
200 				return (EBUSY);
201 			}
202 		LIST_FOREACH(cp, &gp->consumer, consumer)
203 			if (cp->acr || cp->acw || cp->ace) {
204 				g_topology_unlock();
205 				return (EBUSY);
206 			}
207 		/* If the geom is withering, wait for it to finish. */
208 		if (gp->flags & G_GEOM_WITHER) {
209 			g_topology_sleep(mp, 1);
210 			goto retry;
211 		}
212 	}
213 
214 	/*
215 	 * We allow unloading if we have no geoms, or a class
216 	 * method we can use to get rid of them.
217 	 */
218 	if (!LIST_EMPTY(&mp->geom) && mp->destroy_geom == NULL) {
219 		g_topology_unlock();
220 		return (EOPNOTSUPP);
221 	}
222 
223 	/* Bar new entries */
224 	mp->taste = NULL;
225 	mp->config = NULL;
226 
227 	LIST_FOREACH(gp, &mp->geom, geom) {
228 		error = mp->destroy_geom(NULL, mp, gp);
229 		if (error != 0) {
230 			g_topology_unlock();
231 			return (error);
232 		}
233 	}
234 	/* Wait for withering to finish. */
235 	for (;;) {
236 		gp = LIST_FIRST(&mp->geom);
237 		if (gp == NULL)
238 			break;
239 		KASSERT(gp->flags & G_GEOM_WITHER,
240 		   ("Non-withering geom in class %s", mp->name));
241 		g_topology_sleep(mp, 1);
242 	}
243 	G_VALID_CLASS(mp);
244 	if (mp->fini != NULL)
245 		mp->fini(mp);
246 	LIST_REMOVE(mp, class);
247 	g_topology_unlock();
248 
249 	return (0);
250 }
251 
252 int
253 g_modevent(module_t mod, int type, void *data)
254 {
255 	struct g_hh00 *hh;
256 	int error;
257 	static int g_ignition;
258 	struct g_class *mp;
259 
260 	mp = data;
261 	if (mp->version != G_VERSION) {
262 		printf("GEOM class %s has Wrong version %x\n",
263 		    mp->name, mp->version);
264 		return (EINVAL);
265 	}
266 	if (!g_ignition) {
267 		g_ignition++;
268 		g_init();
269 	}
270 	error = EOPNOTSUPP;
271 	switch (type) {
272 	case MOD_LOAD:
273 		g_trace(G_T_TOPOLOGY, "g_modevent(%s, LOAD)", mp->name);
274 		hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
275 		hh->mp = mp;
276 		/*
277 		 * Once the system is not cold, MOD_LOAD calls will be
278 		 * from the userland and the g_event thread will be able
279 		 * to acknowledge their completion.
280 		 */
281 		if (cold) {
282 			hh->post = 1;
283 			error = g_post_event(g_load_class, hh, M_WAITOK, NULL);
284 		} else {
285 			error = g_waitfor_event(g_load_class, hh, M_WAITOK,
286 			    NULL);
287 			if (error == 0)
288 				error = hh->error;
289 			g_free(hh);
290 		}
291 		break;
292 	case MOD_UNLOAD:
293 		g_trace(G_T_TOPOLOGY, "g_modevent(%s, UNLOAD)", mp->name);
294 		error = g_unload_class(mp);
295 		if (error == 0) {
296 			KASSERT(LIST_EMPTY(&mp->geom),
297 			    ("Unloaded class (%s) still has geom", mp->name));
298 		}
299 		break;
300 	}
301 	return (error);
302 }
303 
304 static void
305 g_retaste_event(void *arg, int flag)
306 {
307 	struct g_class *mp, *mp2;
308 	struct g_geom *gp;
309 	struct g_hh00 *hh;
310 	struct g_provider *pp;
311 	struct g_consumer *cp;
312 
313 	g_topology_assert();
314 	if (flag == EV_CANCEL)  /* XXX: can't happen ? */
315 		return;
316 	if (g_shutdown || g_notaste)
317 		return;
318 
319 	hh = arg;
320 	mp = hh->mp;
321 	hh->error = 0;
322 	if (hh->post) {
323 		g_free(hh);
324 		hh = NULL;
325 	}
326 	g_trace(G_T_TOPOLOGY, "g_retaste(%s)", mp->name);
327 
328 	LIST_FOREACH(mp2, &g_classes, class) {
329 		LIST_FOREACH(gp, &mp2->geom, geom) {
330 			LIST_FOREACH(pp, &gp->provider, provider) {
331 				if (pp->acr || pp->acw || pp->ace)
332 					continue;
333 				LIST_FOREACH(cp, &pp->consumers, consumers) {
334 					if (cp->geom->class == mp &&
335 					    (cp->flags & G_CF_ORPHAN) == 0)
336 						break;
337 				}
338 				if (cp != NULL) {
339 					cp->flags |= G_CF_ORPHAN;
340 					g_wither_geom(cp->geom, ENXIO);
341 				}
342 				mp->taste(mp, pp, 0);
343 				g_topology_assert();
344 			}
345 		}
346 	}
347 }
348 
349 int
350 g_retaste(struct g_class *mp)
351 {
352 	struct g_hh00 *hh;
353 	int error;
354 
355 	if (mp->taste == NULL)
356 		return (EINVAL);
357 
358 	hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
359 	hh->mp = mp;
360 
361 	if (cold) {
362 		hh->post = 1;
363 		error = g_post_event(g_retaste_event, hh, M_WAITOK, NULL);
364 	} else {
365 		error = g_waitfor_event(g_retaste_event, hh, M_WAITOK, NULL);
366 		if (error == 0)
367 			error = hh->error;
368 		g_free(hh);
369 	}
370 
371 	return (error);
372 }
373 
374 struct g_geom *
375 g_new_geomf(struct g_class *mp, const char *fmt, ...)
376 {
377 	struct g_geom *gp;
378 	va_list ap;
379 	struct sbuf *sb;
380 
381 	g_topology_assert();
382 	G_VALID_CLASS(mp);
383 	sb = sbuf_new_auto();
384 	va_start(ap, fmt);
385 	sbuf_vprintf(sb, fmt, ap);
386 	va_end(ap);
387 	sbuf_finish(sb);
388 	gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO);
389 	gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
390 	gp->class = mp;
391 	gp->rank = 1;
392 	LIST_INIT(&gp->consumer);
393 	LIST_INIT(&gp->provider);
394 	LIST_INSERT_HEAD(&mp->geom, gp, geom);
395 	TAILQ_INSERT_HEAD(&geoms, gp, geoms);
396 	strcpy(gp->name, sbuf_data(sb));
397 	sbuf_delete(sb);
398 	/* Fill in defaults from class */
399 	gp->start = mp->start;
400 	gp->spoiled = mp->spoiled;
401 	gp->attrchanged = mp->attrchanged;
402 	gp->providergone = mp->providergone;
403 	gp->dumpconf = mp->dumpconf;
404 	gp->access = mp->access;
405 	gp->orphan = mp->orphan;
406 	gp->ioctl = mp->ioctl;
407 	gp->resize = mp->resize;
408 	return (gp);
409 }
410 
411 void
412 g_destroy_geom(struct g_geom *gp)
413 {
414 
415 	g_topology_assert();
416 	G_VALID_GEOM(gp);
417 	g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
418 	KASSERT(LIST_EMPTY(&gp->consumer),
419 	    ("g_destroy_geom(%s) with consumer(s) [%p]",
420 	    gp->name, LIST_FIRST(&gp->consumer)));
421 	KASSERT(LIST_EMPTY(&gp->provider),
422 	    ("g_destroy_geom(%s) with provider(s) [%p]",
423 	    gp->name, LIST_FIRST(&gp->provider)));
424 	g_cancel_event(gp);
425 	LIST_REMOVE(gp, geom);
426 	TAILQ_REMOVE(&geoms, gp, geoms);
427 	g_free(gp->name);
428 	g_free(gp);
429 }
430 
431 /*
432  * This function is called (repeatedly) until the geom has withered away.
433  */
434 void
435 g_wither_geom(struct g_geom *gp, int error)
436 {
437 	struct g_provider *pp;
438 
439 	g_topology_assert();
440 	G_VALID_GEOM(gp);
441 	g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name);
442 	if (!(gp->flags & G_GEOM_WITHER)) {
443 		gp->flags |= G_GEOM_WITHER;
444 		LIST_FOREACH(pp, &gp->provider, provider)
445 			if (!(pp->flags & G_PF_ORPHAN))
446 				g_orphan_provider(pp, error);
447 	}
448 	g_do_wither();
449 }
450 
451 /*
452  * Convenience function to destroy a particular provider.
453  */
454 void
455 g_wither_provider(struct g_provider *pp, int error)
456 {
457 
458 	pp->flags |= G_PF_WITHER;
459 	if (!(pp->flags & G_PF_ORPHAN))
460 		g_orphan_provider(pp, error);
461 }
462 
463 /*
464  * This function is called (repeatedly) until the has withered away.
465  */
466 void
467 g_wither_geom_close(struct g_geom *gp, int error)
468 {
469 	struct g_consumer *cp;
470 
471 	g_topology_assert();
472 	G_VALID_GEOM(gp);
473 	g_trace(G_T_TOPOLOGY, "g_wither_geom_close(%p(%s))", gp, gp->name);
474 	LIST_FOREACH(cp, &gp->consumer, consumer)
475 		if (cp->acr || cp->acw || cp->ace)
476 			g_access(cp, -cp->acr, -cp->acw, -cp->ace);
477 	g_wither_geom(gp, error);
478 }
479 
480 /*
481  * This function is called (repeatedly) until we cant wash away more
482  * withered bits at present.
483  */
484 void
485 g_wither_washer()
486 {
487 	struct g_class *mp;
488 	struct g_geom *gp, *gp2;
489 	struct g_provider *pp, *pp2;
490 	struct g_consumer *cp, *cp2;
491 
492 	g_topology_assert();
493 	LIST_FOREACH(mp, &g_classes, class) {
494 		LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
495 			LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
496 				if (!(pp->flags & G_PF_WITHER))
497 					continue;
498 				if (LIST_EMPTY(&pp->consumers))
499 					g_destroy_provider(pp);
500 			}
501 			if (!(gp->flags & G_GEOM_WITHER))
502 				continue;
503 			LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
504 				if (LIST_EMPTY(&pp->consumers))
505 					g_destroy_provider(pp);
506 			}
507 			LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp2) {
508 				if (cp->acr || cp->acw || cp->ace)
509 					continue;
510 				if (cp->provider != NULL)
511 					g_detach(cp);
512 				g_destroy_consumer(cp);
513 			}
514 			if (LIST_EMPTY(&gp->provider) &&
515 			    LIST_EMPTY(&gp->consumer))
516 				g_destroy_geom(gp);
517 		}
518 	}
519 }
520 
521 struct g_consumer *
522 g_new_consumer(struct g_geom *gp)
523 {
524 	struct g_consumer *cp;
525 
526 	g_topology_assert();
527 	G_VALID_GEOM(gp);
528 	KASSERT(!(gp->flags & G_GEOM_WITHER),
529 	    ("g_new_consumer on WITHERing geom(%s) (class %s)",
530 	    gp->name, gp->class->name));
531 	KASSERT(gp->orphan != NULL,
532 	    ("g_new_consumer on geom(%s) (class %s) without orphan",
533 	    gp->name, gp->class->name));
534 
535 	cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO);
536 	cp->geom = gp;
537 	cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED,
538 	    DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
539 	LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
540 	return(cp);
541 }
542 
543 void
544 g_destroy_consumer(struct g_consumer *cp)
545 {
546 	struct g_geom *gp;
547 
548 	g_topology_assert();
549 	G_VALID_CONSUMER(cp);
550 	g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
551 	KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
552 	KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
553 	KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
554 	KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
555 	g_cancel_event(cp);
556 	gp = cp->geom;
557 	LIST_REMOVE(cp, consumer);
558 	devstat_remove_entry(cp->stat);
559 	g_free(cp);
560 	if (gp->flags & G_GEOM_WITHER)
561 		g_do_wither();
562 }
563 
564 static void
565 g_new_provider_event(void *arg, int flag)
566 {
567 	struct g_class *mp;
568 	struct g_provider *pp;
569 	struct g_consumer *cp, *next_cp;
570 
571 	g_topology_assert();
572 	if (flag == EV_CANCEL)
573 		return;
574 	if (g_shutdown)
575 		return;
576 	pp = arg;
577 	G_VALID_PROVIDER(pp);
578 	if ((pp->flags & G_PF_WITHER) != 0)
579 		return;
580 	LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, next_cp) {
581 		if ((cp->flags & G_CF_ORPHAN) == 0 &&
582 		    cp->geom->attrchanged != NULL)
583 			cp->geom->attrchanged(cp, "GEOM::media");
584 	}
585 	if (g_notaste)
586 		return;
587 	LIST_FOREACH(mp, &g_classes, class) {
588 		if (mp->taste == NULL)
589 			continue;
590 		LIST_FOREACH(cp, &pp->consumers, consumers)
591 			if (cp->geom->class == mp &&
592 			    (cp->flags & G_CF_ORPHAN) == 0)
593 				break;
594 		if (cp != NULL)
595 			continue;
596 		mp->taste(mp, pp, 0);
597 		g_topology_assert();
598 	}
599 }
600 
601 struct g_provider *
602 g_new_providerf(struct g_geom *gp, const char *fmt, ...)
603 {
604 	struct g_provider *pp;
605 	struct sbuf *sb;
606 	va_list ap;
607 
608 	g_topology_assert();
609 	G_VALID_GEOM(gp);
610 	KASSERT(gp->access != NULL,
611 	    ("new provider on geom(%s) without ->access (class %s)",
612 	    gp->name, gp->class->name));
613 	KASSERT(gp->start != NULL,
614 	    ("new provider on geom(%s) without ->start (class %s)",
615 	    gp->name, gp->class->name));
616 	KASSERT(!(gp->flags & G_GEOM_WITHER),
617 	    ("new provider on WITHERing geom(%s) (class %s)",
618 	    gp->name, gp->class->name));
619 	sb = sbuf_new_auto();
620 	va_start(ap, fmt);
621 	sbuf_vprintf(sb, fmt, ap);
622 	va_end(ap);
623 	sbuf_finish(sb);
624 	pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
625 	pp->name = (char *)(pp + 1);
626 	strcpy(pp->name, sbuf_data(sb));
627 	sbuf_delete(sb);
628 	LIST_INIT(&pp->consumers);
629 	LIST_INIT(&pp->aliases);
630 	pp->error = ENXIO;
631 	pp->geom = gp;
632 	pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED,
633 	    DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
634 	LIST_INSERT_HEAD(&gp->provider, pp, provider);
635 	g_post_event(g_new_provider_event, pp, M_WAITOK, pp, gp, NULL);
636 	return (pp);
637 }
638 
639 void
640 g_provider_add_alias(struct g_provider *pp, const char *fmt, ...)
641 {
642 	struct sbuf *sb;
643 	struct g_geom_alias *gap;
644 	va_list ap;
645 
646 	/*
647 	 * Generate the alias string and save it in the list.
648 	 */
649 	sb = sbuf_new_auto();
650 	va_start(ap, fmt);
651 	sbuf_vprintf(sb, fmt, ap);
652 	va_end(ap);
653 	sbuf_finish(sb);
654 
655 	LIST_FOREACH(gap, &pp->aliases, ga_next) {
656 		if (strcmp(gap->ga_alias, sbuf_data(sb)) != 0)
657 			continue;
658 		/* Don't re-add the same alias. */
659 		sbuf_delete(sb);
660 		return;
661 	}
662 
663 	gap = g_malloc(sizeof(*gap) + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
664 	memcpy((char *)(gap + 1), sbuf_data(sb), sbuf_len(sb));
665 	sbuf_delete(sb);
666 	gap->ga_alias = (const char *)(gap + 1);
667 	LIST_INSERT_HEAD(&pp->aliases, gap, ga_next);
668 }
669 
670 void
671 g_error_provider(struct g_provider *pp, int error)
672 {
673 
674 	/* G_VALID_PROVIDER(pp);  We may not have g_topology */
675 	pp->error = error;
676 }
677 
678 static void
679 g_resize_provider_event(void *arg, int flag)
680 {
681 	struct g_hh00 *hh;
682 	struct g_class *mp;
683 	struct g_geom *gp;
684 	struct g_provider *pp;
685 	struct g_consumer *cp, *cp2;
686 	off_t size;
687 
688 	g_topology_assert();
689 	if (g_shutdown)
690 		return;
691 
692 	hh = arg;
693 	pp = hh->pp;
694 	size = hh->size;
695 	g_free(hh);
696 
697 	G_VALID_PROVIDER(pp);
698 	KASSERT(!(pp->flags & G_PF_WITHER),
699 	    ("g_resize_provider_event but withered"));
700 	g_trace(G_T_TOPOLOGY, "g_resize_provider_event(%p)", pp);
701 
702 	LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, cp2) {
703 		gp = cp->geom;
704 		if (gp->resize == NULL && size < pp->mediasize) {
705 			/*
706 			 * XXX: g_dev_orphan method does deferred destroying
707 			 * and it is possible, that other event could already
708 			 * call the orphan method. Check consumer's flags to
709 			 * do not schedule it twice.
710 			 */
711 			if (cp->flags & G_CF_ORPHAN)
712 				continue;
713 			cp->flags |= G_CF_ORPHAN;
714 			cp->geom->orphan(cp);
715 		}
716 	}
717 
718 	pp->mediasize = size;
719 
720 	LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, cp2) {
721 		gp = cp->geom;
722 		if ((gp->flags & G_GEOM_WITHER) == 0 && gp->resize != NULL)
723 			gp->resize(cp);
724 	}
725 
726 	/*
727 	 * After resizing, the previously invalid GEOM class metadata
728 	 * might become valid.  This means we should retaste.
729 	 */
730 	LIST_FOREACH(mp, &g_classes, class) {
731 		if (mp->taste == NULL)
732 			continue;
733 		LIST_FOREACH(cp, &pp->consumers, consumers)
734 			if (cp->geom->class == mp &&
735 			    (cp->flags & G_CF_ORPHAN) == 0)
736 				break;
737 		if (cp != NULL)
738 			continue;
739 		mp->taste(mp, pp, 0);
740 		g_topology_assert();
741 	}
742 }
743 
744 void
745 g_resize_provider(struct g_provider *pp, off_t size)
746 {
747 	struct g_hh00 *hh;
748 
749 	G_VALID_PROVIDER(pp);
750 	if (pp->flags & G_PF_WITHER)
751 		return;
752 
753 	if (size == pp->mediasize)
754 		return;
755 
756 	hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
757 	hh->pp = pp;
758 	hh->size = size;
759 	g_post_event(g_resize_provider_event, hh, M_WAITOK, NULL);
760 }
761 
762 struct g_provider *
763 g_provider_by_name(char const *arg)
764 {
765 	struct g_class *cp;
766 	struct g_geom *gp;
767 	struct g_provider *pp, *wpp;
768 
769 	if (strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
770 		arg += sizeof(_PATH_DEV) - 1;
771 
772 	wpp = NULL;
773 	LIST_FOREACH(cp, &g_classes, class) {
774 		LIST_FOREACH(gp, &cp->geom, geom) {
775 			LIST_FOREACH(pp, &gp->provider, provider) {
776 				if (strcmp(arg, pp->name) != 0)
777 					continue;
778 				if ((gp->flags & G_GEOM_WITHER) == 0 &&
779 				    (pp->flags & G_PF_WITHER) == 0)
780 					return (pp);
781 				else
782 					wpp = pp;
783 			}
784 		}
785 	}
786 
787 	return (wpp);
788 }
789 
790 void
791 g_destroy_provider(struct g_provider *pp)
792 {
793 	struct g_geom *gp;
794 	struct g_geom_alias *gap, *gaptmp;
795 
796 	g_topology_assert();
797 	G_VALID_PROVIDER(pp);
798 	KASSERT(LIST_EMPTY(&pp->consumers),
799 	    ("g_destroy_provider but attached"));
800 	KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
801 	KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
802 	KASSERT (pp->ace == 0, ("g_destroy_provider with ace"));
803 	g_cancel_event(pp);
804 	LIST_REMOVE(pp, provider);
805 	gp = pp->geom;
806 	devstat_remove_entry(pp->stat);
807 	/*
808 	 * If a callback was provided, send notification that the provider
809 	 * is now gone.
810 	 */
811 	if (gp->providergone != NULL)
812 		gp->providergone(pp);
813 	LIST_FOREACH_SAFE(gap, &pp->aliases, ga_next, gaptmp)
814 		g_free(gap);
815 	g_free(pp);
816 	if ((gp->flags & G_GEOM_WITHER))
817 		g_do_wither();
818 }
819 
820 /*
821  * We keep the "geoms" list sorted by topological order (== increasing
822  * numerical rank) at all times.
823  * When an attach is done, the attaching geoms rank is invalidated
824  * and it is moved to the tail of the list.
825  * All geoms later in the sequence has their ranks reevaluated in
826  * sequence.  If we cannot assign rank to a geom because it's
827  * prerequisites do not have rank, we move that element to the tail
828  * of the sequence with invalid rank as well.
829  * At some point we encounter our original geom and if we stil fail
830  * to assign it a rank, there must be a loop and we fail back to
831  * g_attach() which detach again and calls redo_rank again
832  * to fix up the damage.
833  * It would be much simpler code wise to do it recursively, but we
834  * can't risk that on the kernel stack.
835  */
836 
837 static int
838 redo_rank(struct g_geom *gp)
839 {
840 	struct g_consumer *cp;
841 	struct g_geom *gp1, *gp2;
842 	int n, m;
843 
844 	g_topology_assert();
845 	G_VALID_GEOM(gp);
846 
847 	/* Invalidate this geoms rank and move it to the tail */
848 	gp1 = TAILQ_NEXT(gp, geoms);
849 	if (gp1 != NULL) {
850 		gp->rank = 0;
851 		TAILQ_REMOVE(&geoms, gp, geoms);
852 		TAILQ_INSERT_TAIL(&geoms, gp, geoms);
853 	} else {
854 		gp1 = gp;
855 	}
856 
857 	/* re-rank the rest of the sequence */
858 	for (; gp1 != NULL; gp1 = gp2) {
859 		gp1->rank = 0;
860 		m = 1;
861 		LIST_FOREACH(cp, &gp1->consumer, consumer) {
862 			if (cp->provider == NULL)
863 				continue;
864 			n = cp->provider->geom->rank;
865 			if (n == 0) {
866 				m = 0;
867 				break;
868 			} else if (n >= m)
869 				m = n + 1;
870 		}
871 		gp1->rank = m;
872 		gp2 = TAILQ_NEXT(gp1, geoms);
873 
874 		/* got a rank, moving on */
875 		if (m != 0)
876 			continue;
877 
878 		/* no rank to original geom means loop */
879 		if (gp == gp1)
880 			return (ELOOP);
881 
882 		/* no rank, put it at the end move on */
883 		TAILQ_REMOVE(&geoms, gp1, geoms);
884 		TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
885 	}
886 	return (0);
887 }
888 
889 int
890 g_attach(struct g_consumer *cp, struct g_provider *pp)
891 {
892 	int error;
893 
894 	g_topology_assert();
895 	G_VALID_CONSUMER(cp);
896 	G_VALID_PROVIDER(pp);
897 	g_trace(G_T_TOPOLOGY, "g_attach(%p, %p)", cp, pp);
898 	KASSERT(cp->provider == NULL, ("attach but attached"));
899 	if ((pp->flags & (G_PF_ORPHAN | G_PF_WITHER)) != 0)
900 		return (ENXIO);
901 	cp->provider = pp;
902 	cp->flags &= ~G_CF_ORPHAN;
903 	LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
904 	error = redo_rank(cp->geom);
905 	if (error) {
906 		LIST_REMOVE(cp, consumers);
907 		cp->provider = NULL;
908 		redo_rank(cp->geom);
909 	}
910 	return (error);
911 }
912 
913 void
914 g_detach(struct g_consumer *cp)
915 {
916 	struct g_provider *pp;
917 
918 	g_topology_assert();
919 	G_VALID_CONSUMER(cp);
920 	g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp);
921 	KASSERT(cp->provider != NULL, ("detach but not attached"));
922 	KASSERT(cp->acr == 0, ("detach but nonzero acr"));
923 	KASSERT(cp->acw == 0, ("detach but nonzero acw"));
924 	KASSERT(cp->ace == 0, ("detach but nonzero ace"));
925 	KASSERT(cp->nstart == cp->nend,
926 	    ("detach with active requests"));
927 	pp = cp->provider;
928 	LIST_REMOVE(cp, consumers);
929 	cp->provider = NULL;
930 	if ((cp->geom->flags & G_GEOM_WITHER) ||
931 	    (pp->geom->flags & G_GEOM_WITHER) ||
932 	    (pp->flags & G_PF_WITHER))
933 		g_do_wither();
934 	redo_rank(cp->geom);
935 }
936 
937 /*
938  * g_access()
939  *
940  * Access-check with delta values.  The question asked is "can provider
941  * "cp" change the access counters by the relative amounts dc[rwe] ?"
942  */
943 
944 int
945 g_access(struct g_consumer *cp, int dcr, int dcw, int dce)
946 {
947 	struct g_provider *pp;
948 	struct g_geom *gp;
949 	int pw, pe;
950 #ifdef INVARIANTS
951 	int sr, sw, se;
952 #endif
953 	int error;
954 
955 	g_topology_assert();
956 	G_VALID_CONSUMER(cp);
957 	pp = cp->provider;
958 	KASSERT(pp != NULL, ("access but not attached"));
959 	G_VALID_PROVIDER(pp);
960 	gp = pp->geom;
961 
962 	g_trace(G_T_ACCESS, "g_access(%p(%s), %d, %d, %d)",
963 	    cp, pp->name, dcr, dcw, dce);
964 
965 	KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
966 	KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
967 	KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
968 	KASSERT(dcr != 0 || dcw != 0 || dce != 0, ("NOP access request"));
969 	KASSERT(cp->acr + dcr != 0 || cp->acw + dcw != 0 ||
970 	    cp->ace + dce != 0 || cp->nstart == cp->nend,
971 	    ("Last close with active requests"));
972 	KASSERT(gp->access != NULL, ("NULL geom->access"));
973 
974 	/*
975 	 * If our class cares about being spoiled, and we have been, we
976 	 * are probably just ahead of the event telling us that.  Fail
977 	 * now rather than having to unravel this later.
978 	 */
979 	if (cp->geom->spoiled != NULL && (cp->flags & G_CF_SPOILED) &&
980 	    (dcr > 0 || dcw > 0 || dce > 0))
981 		return (ENXIO);
982 
983 	/*
984 	 * A number of GEOM classes either need to perform an I/O on the first
985 	 * open or to acquire a different subsystem's lock.  To do that they
986 	 * may have to drop the topology lock.
987 	 * Other GEOM classes perform special actions when opening a lower rank
988 	 * geom for the first time.  As a result, more than one thread may
989 	 * end up performing the special actions.
990 	 * So, we prevent concurrent "first" opens by marking the consumer with
991 	 * special flag.
992 	 *
993 	 * Note that if the geom's access method never drops the topology lock,
994 	 * then we will never see G_GEOM_IN_ACCESS here.
995 	 */
996 	while ((gp->flags & G_GEOM_IN_ACCESS) != 0) {
997 		g_trace(G_T_ACCESS,
998 		    "%s: race on geom %s via provider %s and consumer of %s",
999 		    __func__, gp->name, pp->name, cp->geom->name);
1000 		gp->flags |= G_GEOM_ACCESS_WAIT;
1001 		g_topology_sleep(gp, 0);
1002 	}
1003 
1004 	/*
1005 	 * Figure out what counts the provider would have had, if this
1006 	 * consumer had (r0w0e0) at this time.
1007 	 */
1008 	pw = pp->acw - cp->acw;
1009 	pe = pp->ace - cp->ace;
1010 
1011 	g_trace(G_T_ACCESS,
1012     "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
1013 	    dcr, dcw, dce,
1014 	    cp->acr, cp->acw, cp->ace,
1015 	    pp->acr, pp->acw, pp->ace,
1016 	    pp, pp->name);
1017 
1018 	/* If foot-shooting is enabled, any open on rank#1 is OK */
1019 	if ((g_debugflags & G_F_FOOTSHOOTING) && gp->rank == 1)
1020 		;
1021 	/* If we try exclusive but already write: fail */
1022 	else if (dce > 0 && pw > 0)
1023 		return (EPERM);
1024 	/* If we try write but already exclusive: fail */
1025 	else if (dcw > 0 && pe > 0)
1026 		return (EPERM);
1027 	/* If we try to open more but provider is error'ed: fail */
1028 	else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0) {
1029 		printf("%s(%d): provider %s has error %d set\n",
1030 		    __func__, __LINE__, pp->name, pp->error);
1031 		return (pp->error);
1032 	}
1033 
1034 	/* Ok then... */
1035 
1036 #ifdef INVARIANTS
1037 	sr = cp->acr;
1038 	sw = cp->acw;
1039 	se = cp->ace;
1040 #endif
1041 	gp->flags |= G_GEOM_IN_ACCESS;
1042 	error = gp->access(pp, dcr, dcw, dce);
1043 	KASSERT(dcr > 0 || dcw > 0 || dce > 0 || error == 0,
1044 	    ("Geom provider %s::%s dcr=%d dcw=%d dce=%d error=%d failed "
1045 	    "closing ->access()", gp->class->name, pp->name, dcr, dcw,
1046 	    dce, error));
1047 
1048 	g_topology_assert();
1049 	gp->flags &= ~G_GEOM_IN_ACCESS;
1050 	KASSERT(cp->acr == sr && cp->acw == sw && cp->ace == se,
1051 	    ("Access counts changed during geom->access"));
1052 	if ((gp->flags & G_GEOM_ACCESS_WAIT) != 0) {
1053 		gp->flags &= ~G_GEOM_ACCESS_WAIT;
1054 		wakeup(gp);
1055 	}
1056 
1057 	if (!error) {
1058 		/*
1059 		 * If we open first write, spoil any partner consumers.
1060 		 * If we close last write and provider is not errored,
1061 		 * trigger re-taste.
1062 		 */
1063 		if (pp->acw == 0 && dcw != 0)
1064 			g_spoil(pp, cp);
1065 		else if (pp->acw != 0 && pp->acw == -dcw && pp->error == 0 &&
1066 		    !(gp->flags & G_GEOM_WITHER))
1067 			g_post_event(g_new_provider_event, pp, M_WAITOK,
1068 			    pp, NULL);
1069 
1070 		pp->acr += dcr;
1071 		pp->acw += dcw;
1072 		pp->ace += dce;
1073 		cp->acr += dcr;
1074 		cp->acw += dcw;
1075 		cp->ace += dce;
1076 		if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)
1077 			KASSERT(pp->sectorsize > 0,
1078 			    ("Provider %s lacks sectorsize", pp->name));
1079 		if ((cp->geom->flags & G_GEOM_WITHER) &&
1080 		    cp->acr == 0 && cp->acw == 0 && cp->ace == 0)
1081 			g_do_wither();
1082 	}
1083 	return (error);
1084 }
1085 
1086 int
1087 g_handleattr_int(struct bio *bp, const char *attribute, int val)
1088 {
1089 
1090 	return (g_handleattr(bp, attribute, &val, sizeof val));
1091 }
1092 
1093 int
1094 g_handleattr_uint16_t(struct bio *bp, const char *attribute, uint16_t val)
1095 {
1096 
1097 	return (g_handleattr(bp, attribute, &val, sizeof val));
1098 }
1099 
1100 int
1101 g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val)
1102 {
1103 
1104 	return (g_handleattr(bp, attribute, &val, sizeof val));
1105 }
1106 
1107 int
1108 g_handleattr_str(struct bio *bp, const char *attribute, const char *str)
1109 {
1110 
1111 	return (g_handleattr(bp, attribute, str, 0));
1112 }
1113 
1114 int
1115 g_handleattr(struct bio *bp, const char *attribute, const void *val, int len)
1116 {
1117 	int error = 0;
1118 
1119 	if (strcmp(bp->bio_attribute, attribute))
1120 		return (0);
1121 	if (len == 0) {
1122 		bzero(bp->bio_data, bp->bio_length);
1123 		if (strlcpy(bp->bio_data, val, bp->bio_length) >=
1124 		    bp->bio_length) {
1125 			printf("%s: %s %s bio_length %jd strlen %zu -> EFAULT\n",
1126 			    __func__, bp->bio_to->name, attribute,
1127 			    (intmax_t)bp->bio_length, strlen(val));
1128 			error = EFAULT;
1129 		}
1130 	} else if (bp->bio_length == len) {
1131 		bcopy(val, bp->bio_data, len);
1132 	} else {
1133 		printf("%s: %s %s bio_length %jd len %d -> EFAULT\n", __func__,
1134 		    bp->bio_to->name, attribute, (intmax_t)bp->bio_length, len);
1135 		error = EFAULT;
1136 	}
1137 	if (error == 0)
1138 		bp->bio_completed = bp->bio_length;
1139 	g_io_deliver(bp, error);
1140 	return (1);
1141 }
1142 
1143 int
1144 g_std_access(struct g_provider *pp,
1145 	int dr __unused, int dw __unused, int de __unused)
1146 {
1147 
1148 	g_topology_assert();
1149 	G_VALID_PROVIDER(pp);
1150         return (0);
1151 }
1152 
1153 void
1154 g_std_done(struct bio *bp)
1155 {
1156 	struct bio *bp2;
1157 
1158 	bp2 = bp->bio_parent;
1159 	if (bp2->bio_error == 0)
1160 		bp2->bio_error = bp->bio_error;
1161 	bp2->bio_completed += bp->bio_completed;
1162 	g_destroy_bio(bp);
1163 	bp2->bio_inbed++;
1164 	if (bp2->bio_children == bp2->bio_inbed) {
1165 		if (bp2->bio_cmd == BIO_SPEEDUP)
1166 			bp2->bio_completed = bp2->bio_length;
1167 		g_io_deliver(bp2, bp2->bio_error);
1168 	}
1169 }
1170 
1171 /* XXX: maybe this is only g_slice_spoiled */
1172 
1173 void
1174 g_std_spoiled(struct g_consumer *cp)
1175 {
1176 	struct g_geom *gp;
1177 	struct g_provider *pp;
1178 
1179 	g_topology_assert();
1180 	G_VALID_CONSUMER(cp);
1181 	g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
1182 	cp->flags |= G_CF_ORPHAN;
1183 	g_detach(cp);
1184 	gp = cp->geom;
1185 	LIST_FOREACH(pp, &gp->provider, provider)
1186 		g_orphan_provider(pp, ENXIO);
1187 	g_destroy_consumer(cp);
1188 	if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
1189 		g_destroy_geom(gp);
1190 	else
1191 		gp->flags |= G_GEOM_WITHER;
1192 }
1193 
1194 /*
1195  * Spoiling happens when a provider is opened for writing, but consumers
1196  * which are configured by in-band data are attached (slicers for instance).
1197  * Since the write might potentially change the in-band data, such consumers
1198  * need to re-evaluate their existence after the writing session closes.
1199  * We do this by (offering to) tear them down when the open for write happens
1200  * in return for a re-taste when it closes again.
1201  * Together with the fact that such consumers grab an 'e' bit whenever they
1202  * are open, regardless of mode, this ends up DTRT.
1203  */
1204 
1205 static void
1206 g_spoil_event(void *arg, int flag)
1207 {
1208 	struct g_provider *pp;
1209 	struct g_consumer *cp, *cp2;
1210 
1211 	g_topology_assert();
1212 	if (flag == EV_CANCEL)
1213 		return;
1214 	pp = arg;
1215 	G_VALID_PROVIDER(pp);
1216 	g_trace(G_T_TOPOLOGY, "%s %p(%s:%s:%s)", __func__, pp,
1217 	    pp->geom->class->name, pp->geom->name, pp->name);
1218 	for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) {
1219 		cp2 = LIST_NEXT(cp, consumers);
1220 		if ((cp->flags & G_CF_SPOILED) == 0)
1221 			continue;
1222 		cp->flags &= ~G_CF_SPOILED;
1223 		if (cp->geom->spoiled == NULL)
1224 			continue;
1225 		cp->geom->spoiled(cp);
1226 		g_topology_assert();
1227 	}
1228 }
1229 
1230 void
1231 g_spoil(struct g_provider *pp, struct g_consumer *cp)
1232 {
1233 	struct g_consumer *cp2;
1234 
1235 	g_topology_assert();
1236 	G_VALID_PROVIDER(pp);
1237 	G_VALID_CONSUMER(cp);
1238 
1239 	LIST_FOREACH(cp2, &pp->consumers, consumers) {
1240 		if (cp2 == cp)
1241 			continue;
1242 /*
1243 		KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
1244 		KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
1245 */
1246 		KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
1247 		cp2->flags |= G_CF_SPOILED;
1248 	}
1249 	g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL);
1250 }
1251 
1252 static void
1253 g_media_changed_event(void *arg, int flag)
1254 {
1255 	struct g_provider *pp;
1256 	int retaste;
1257 
1258 	g_topology_assert();
1259 	if (flag == EV_CANCEL)
1260 		return;
1261 	pp = arg;
1262 	G_VALID_PROVIDER(pp);
1263 
1264 	/*
1265 	 * If provider was not open for writing, queue retaste after spoiling.
1266 	 * If it was, retaste will happen automatically on close.
1267 	 */
1268 	retaste = (pp->acw == 0 && pp->error == 0 &&
1269 	    !(pp->geom->flags & G_GEOM_WITHER));
1270 	g_spoil_event(arg, flag);
1271 	if (retaste)
1272 		g_post_event(g_new_provider_event, pp, M_WAITOK, pp, NULL);
1273 }
1274 
1275 int
1276 g_media_changed(struct g_provider *pp, int flag)
1277 {
1278 	struct g_consumer *cp;
1279 
1280 	LIST_FOREACH(cp, &pp->consumers, consumers)
1281 		cp->flags |= G_CF_SPOILED;
1282 	return (g_post_event(g_media_changed_event, pp, flag, pp, NULL));
1283 }
1284 
1285 int
1286 g_media_gone(struct g_provider *pp, int flag)
1287 {
1288 	struct g_consumer *cp;
1289 
1290 	LIST_FOREACH(cp, &pp->consumers, consumers)
1291 		cp->flags |= G_CF_SPOILED;
1292 	return (g_post_event(g_spoil_event, pp, flag, pp, NULL));
1293 }
1294 
1295 int
1296 g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len)
1297 {
1298 	int error, i;
1299 
1300 	i = len;
1301 	error = g_io_getattr(attr, cp, &i, var);
1302 	if (error)
1303 		return (error);
1304 	if (i != len)
1305 		return (EINVAL);
1306 	return (0);
1307 }
1308 
1309 static int
1310 g_get_device_prefix_len(const char *name)
1311 {
1312 	int len;
1313 
1314 	if (strncmp(name, "ada", 3) == 0)
1315 		len = 3;
1316 	else if (strncmp(name, "ad", 2) == 0)
1317 		len = 2;
1318 	else
1319 		return (0);
1320 	if (name[len] < '0' || name[len] > '9')
1321 		return (0);
1322 	do {
1323 		len++;
1324 	} while (name[len] >= '0' && name[len] <= '9');
1325 	return (len);
1326 }
1327 
1328 int
1329 g_compare_names(const char *namea, const char *nameb)
1330 {
1331 	int deva, devb;
1332 
1333 	if (strcmp(namea, nameb) == 0)
1334 		return (1);
1335 	deva = g_get_device_prefix_len(namea);
1336 	if (deva == 0)
1337 		return (0);
1338 	devb = g_get_device_prefix_len(nameb);
1339 	if (devb == 0)
1340 		return (0);
1341 	if (strcmp(namea + deva, nameb + devb) == 0)
1342 		return (1);
1343 	return (0);
1344 }
1345 
1346 #if defined(DIAGNOSTIC) || defined(DDB)
1347 /*
1348  * This function walks the mesh and returns a non-zero integer if it
1349  * finds the argument pointer is an object. The return value indicates
1350  * which type of object it is believed to be. If topology is not locked,
1351  * this function is potentially dangerous, but we don't assert that the
1352  * topology lock is held when called from debugger.
1353  */
1354 int
1355 g_valid_obj(void const *ptr)
1356 {
1357 	struct g_class *mp;
1358 	struct g_geom *gp;
1359 	struct g_consumer *cp;
1360 	struct g_provider *pp;
1361 
1362 #ifdef KDB
1363 	if (kdb_active == 0)
1364 #endif
1365 		g_topology_assert();
1366 
1367 	LIST_FOREACH(mp, &g_classes, class) {
1368 		if (ptr == mp)
1369 			return (1);
1370 		LIST_FOREACH(gp, &mp->geom, geom) {
1371 			if (ptr == gp)
1372 				return (2);
1373 			LIST_FOREACH(cp, &gp->consumer, consumer)
1374 				if (ptr == cp)
1375 					return (3);
1376 			LIST_FOREACH(pp, &gp->provider, provider)
1377 				if (ptr == pp)
1378 					return (4);
1379 		}
1380 	}
1381 	return(0);
1382 }
1383 #endif
1384 
1385 #ifdef DDB
1386 
1387 #define	gprintf(...)	do {						\
1388 	db_printf("%*s", indent, "");					\
1389 	db_printf(__VA_ARGS__);						\
1390 } while (0)
1391 #define	gprintln(...)	do {						\
1392 	gprintf(__VA_ARGS__);						\
1393 	db_printf("\n");						\
1394 } while (0)
1395 
1396 #define	ADDFLAG(obj, flag, sflag)	do {				\
1397 	if ((obj)->flags & (flag)) {					\
1398 		if (comma)						\
1399 			strlcat(str, ",", size);			\
1400 		strlcat(str, (sflag), size);				\
1401 		comma = 1;						\
1402 	}								\
1403 } while (0)
1404 
1405 static char *
1406 provider_flags_to_string(struct g_provider *pp, char *str, size_t size)
1407 {
1408 	int comma = 0;
1409 
1410 	bzero(str, size);
1411 	if (pp->flags == 0) {
1412 		strlcpy(str, "NONE", size);
1413 		return (str);
1414 	}
1415 	ADDFLAG(pp, G_PF_WITHER, "G_PF_WITHER");
1416 	ADDFLAG(pp, G_PF_ORPHAN, "G_PF_ORPHAN");
1417 	return (str);
1418 }
1419 
1420 static char *
1421 geom_flags_to_string(struct g_geom *gp, char *str, size_t size)
1422 {
1423 	int comma = 0;
1424 
1425 	bzero(str, size);
1426 	if (gp->flags == 0) {
1427 		strlcpy(str, "NONE", size);
1428 		return (str);
1429 	}
1430 	ADDFLAG(gp, G_GEOM_WITHER, "G_GEOM_WITHER");
1431 	return (str);
1432 }
1433 static void
1434 db_show_geom_consumer(int indent, struct g_consumer *cp)
1435 {
1436 
1437 	if (indent == 0) {
1438 		gprintln("consumer: %p", cp);
1439 		gprintln("  class:    %s (%p)", cp->geom->class->name,
1440 		    cp->geom->class);
1441 		gprintln("  geom:     %s (%p)", cp->geom->name, cp->geom);
1442 		if (cp->provider == NULL)
1443 			gprintln("  provider: none");
1444 		else {
1445 			gprintln("  provider: %s (%p)", cp->provider->name,
1446 			    cp->provider);
1447 		}
1448 		gprintln("  access:   r%dw%de%d", cp->acr, cp->acw, cp->ace);
1449 		gprintln("  flags:    0x%04x", cp->flags);
1450 #ifdef INVARIANTS
1451 		gprintln("  nstart:   %u", cp->nstart);
1452 		gprintln("  nend:     %u", cp->nend);
1453 #endif
1454 	} else {
1455 		gprintf("consumer: %p (%s), access=r%dw%de%d", cp,
1456 		    cp->provider != NULL ? cp->provider->name : "none",
1457 		    cp->acr, cp->acw, cp->ace);
1458 		if (cp->flags)
1459 			db_printf(", flags=0x%04x", cp->flags);
1460 		db_printf("\n");
1461 	}
1462 }
1463 
1464 static void
1465 db_show_geom_provider(int indent, struct g_provider *pp)
1466 {
1467 	struct g_consumer *cp;
1468 	char flags[64];
1469 
1470 	if (indent == 0) {
1471 		gprintln("provider: %s (%p)", pp->name, pp);
1472 		gprintln("  class:        %s (%p)", pp->geom->class->name,
1473 		    pp->geom->class);
1474 		gprintln("  geom:         %s (%p)", pp->geom->name, pp->geom);
1475 		gprintln("  mediasize:    %jd", (intmax_t)pp->mediasize);
1476 		gprintln("  sectorsize:   %u", pp->sectorsize);
1477 		gprintln("  stripesize:   %ju", (uintmax_t)pp->stripesize);
1478 		gprintln("  stripeoffset: %ju", (uintmax_t)pp->stripeoffset);
1479 		gprintln("  access:       r%dw%de%d", pp->acr, pp->acw,
1480 		    pp->ace);
1481 		gprintln("  flags:        %s (0x%04x)",
1482 		    provider_flags_to_string(pp, flags, sizeof(flags)),
1483 		    pp->flags);
1484 		gprintln("  error:        %d", pp->error);
1485 		if (LIST_EMPTY(&pp->consumers))
1486 			gprintln("  consumers:    none");
1487 	} else {
1488 		gprintf("provider: %s (%p), access=r%dw%de%d",
1489 		    pp->name, pp, pp->acr, pp->acw, pp->ace);
1490 		if (pp->flags != 0) {
1491 			db_printf(", flags=%s (0x%04x)",
1492 			    provider_flags_to_string(pp, flags, sizeof(flags)),
1493 			    pp->flags);
1494 		}
1495 		db_printf("\n");
1496 	}
1497 	if (!LIST_EMPTY(&pp->consumers)) {
1498 		LIST_FOREACH(cp, &pp->consumers, consumers) {
1499 			db_show_geom_consumer(indent + 2, cp);
1500 			if (db_pager_quit)
1501 				break;
1502 		}
1503 	}
1504 }
1505 
1506 static void
1507 db_show_geom_geom(int indent, struct g_geom *gp)
1508 {
1509 	struct g_provider *pp;
1510 	struct g_consumer *cp;
1511 	char flags[64];
1512 
1513 	if (indent == 0) {
1514 		gprintln("geom: %s (%p)", gp->name, gp);
1515 		gprintln("  class:     %s (%p)", gp->class->name, gp->class);
1516 		gprintln("  flags:     %s (0x%04x)",
1517 		    geom_flags_to_string(gp, flags, sizeof(flags)), gp->flags);
1518 		gprintln("  rank:      %d", gp->rank);
1519 		if (LIST_EMPTY(&gp->provider))
1520 			gprintln("  providers: none");
1521 		if (LIST_EMPTY(&gp->consumer))
1522 			gprintln("  consumers: none");
1523 	} else {
1524 		gprintf("geom: %s (%p), rank=%d", gp->name, gp, gp->rank);
1525 		if (gp->flags != 0) {
1526 			db_printf(", flags=%s (0x%04x)",
1527 			    geom_flags_to_string(gp, flags, sizeof(flags)),
1528 			    gp->flags);
1529 		}
1530 		db_printf("\n");
1531 	}
1532 	if (!LIST_EMPTY(&gp->provider)) {
1533 		LIST_FOREACH(pp, &gp->provider, provider) {
1534 			db_show_geom_provider(indent + 2, pp);
1535 			if (db_pager_quit)
1536 				break;
1537 		}
1538 	}
1539 	if (!LIST_EMPTY(&gp->consumer)) {
1540 		LIST_FOREACH(cp, &gp->consumer, consumer) {
1541 			db_show_geom_consumer(indent + 2, cp);
1542 			if (db_pager_quit)
1543 				break;
1544 		}
1545 	}
1546 }
1547 
1548 static void
1549 db_show_geom_class(struct g_class *mp)
1550 {
1551 	struct g_geom *gp;
1552 
1553 	db_printf("class: %s (%p)\n", mp->name, mp);
1554 	LIST_FOREACH(gp, &mp->geom, geom) {
1555 		db_show_geom_geom(2, gp);
1556 		if (db_pager_quit)
1557 			break;
1558 	}
1559 }
1560 
1561 /*
1562  * Print the GEOM topology or the given object.
1563  */
1564 DB_SHOW_COMMAND(geom, db_show_geom)
1565 {
1566 	struct g_class *mp;
1567 
1568 	if (!have_addr) {
1569 		/* No address given, print the entire topology. */
1570 		LIST_FOREACH(mp, &g_classes, class) {
1571 			db_show_geom_class(mp);
1572 			db_printf("\n");
1573 			if (db_pager_quit)
1574 				break;
1575 		}
1576 	} else {
1577 		switch (g_valid_obj((void *)addr)) {
1578 		case 1:
1579 			db_show_geom_class((struct g_class *)addr);
1580 			break;
1581 		case 2:
1582 			db_show_geom_geom(0, (struct g_geom *)addr);
1583 			break;
1584 		case 3:
1585 			db_show_geom_consumer(0, (struct g_consumer *)addr);
1586 			break;
1587 		case 4:
1588 			db_show_geom_provider(0, (struct g_provider *)addr);
1589 			break;
1590 		default:
1591 			db_printf("Not a GEOM object.\n");
1592 			break;
1593 		}
1594 	}
1595 }
1596 
1597 static void
1598 db_print_bio_cmd(struct bio *bp)
1599 {
1600 	db_printf("  cmd: ");
1601 	switch (bp->bio_cmd) {
1602 	case BIO_READ: db_printf("BIO_READ"); break;
1603 	case BIO_WRITE: db_printf("BIO_WRITE"); break;
1604 	case BIO_DELETE: db_printf("BIO_DELETE"); break;
1605 	case BIO_GETATTR: db_printf("BIO_GETATTR"); break;
1606 	case BIO_FLUSH: db_printf("BIO_FLUSH"); break;
1607 	case BIO_CMD0: db_printf("BIO_CMD0"); break;
1608 	case BIO_CMD1: db_printf("BIO_CMD1"); break;
1609 	case BIO_CMD2: db_printf("BIO_CMD2"); break;
1610 	case BIO_ZONE: db_printf("BIO_ZONE"); break;
1611 	default: db_printf("UNKNOWN"); break;
1612 	}
1613 	db_printf("\n");
1614 }
1615 
1616 static void
1617 db_print_bio_flags(struct bio *bp)
1618 {
1619 	int comma;
1620 
1621 	comma = 0;
1622 	db_printf("  flags: ");
1623 	if (bp->bio_flags & BIO_ERROR) {
1624 		db_printf("BIO_ERROR");
1625 		comma = 1;
1626 	}
1627 	if (bp->bio_flags & BIO_DONE) {
1628 		db_printf("%sBIO_DONE", (comma ? ", " : ""));
1629 		comma = 1;
1630 	}
1631 	if (bp->bio_flags & BIO_ONQUEUE)
1632 		db_printf("%sBIO_ONQUEUE", (comma ? ", " : ""));
1633 	db_printf("\n");
1634 }
1635 
1636 /*
1637  * Print useful information in a BIO
1638  */
1639 DB_SHOW_COMMAND(bio, db_show_bio)
1640 {
1641 	struct bio *bp;
1642 
1643 	if (have_addr) {
1644 		bp = (struct bio *)addr;
1645 		db_printf("BIO %p\n", bp);
1646 		db_print_bio_cmd(bp);
1647 		db_print_bio_flags(bp);
1648 		db_printf("  cflags: 0x%hx\n", bp->bio_cflags);
1649 		db_printf("  pflags: 0x%hx\n", bp->bio_pflags);
1650 		db_printf("  offset: %jd\n", (intmax_t)bp->bio_offset);
1651 		db_printf("  length: %jd\n", (intmax_t)bp->bio_length);
1652 		db_printf("  bcount: %ld\n", bp->bio_bcount);
1653 		db_printf("  resid: %ld\n", bp->bio_resid);
1654 		db_printf("  completed: %jd\n", (intmax_t)bp->bio_completed);
1655 		db_printf("  children: %u\n", bp->bio_children);
1656 		db_printf("  inbed: %u\n", bp->bio_inbed);
1657 		db_printf("  error: %d\n", bp->bio_error);
1658 		db_printf("  parent: %p\n", bp->bio_parent);
1659 		db_printf("  driver1: %p\n", bp->bio_driver1);
1660 		db_printf("  driver2: %p\n", bp->bio_driver2);
1661 		db_printf("  caller1: %p\n", bp->bio_caller1);
1662 		db_printf("  caller2: %p\n", bp->bio_caller2);
1663 		db_printf("  bio_from: %p\n", bp->bio_from);
1664 		db_printf("  bio_to: %p\n", bp->bio_to);
1665 
1666 #if defined(BUF_TRACKING) || defined(FULL_BUF_TRACKING)
1667 		db_printf("  bio_track_bp: %p\n", bp->bio_track_bp);
1668 #endif
1669 	}
1670 }
1671 
1672 #undef	gprintf
1673 #undef	gprintln
1674 #undef	ADDFLAG
1675 
1676 #endif	/* DDB */
1677