xref: /freebsd/sys/geom/geom_subr.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
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/sysctl.h>
48 #include <sys/proc.h>
49 #include <sys/kthread.h>
50 #include <sys/lock.h>
51 #include <sys/mutex.h>
52 #include <sys/errno.h>
53 #include <sys/sbuf.h>
54 #include <sys/sdt.h>
55 #include <geom/geom.h>
56 #include <geom/geom_dbg.h>
57 #include <geom/geom_int.h>
58 #include <machine/stdarg.h>
59 
60 #ifdef DDB
61 #include <ddb/ddb.h>
62 #endif
63 
64 #ifdef KDB
65 #include <sys/kdb.h>
66 #endif
67 
68 SDT_PROVIDER_DEFINE(geom);
69 
70 struct class_list_head g_classes = LIST_HEAD_INITIALIZER(g_classes);
71 static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms);
72 char *g_wait_event, *g_wait_up, *g_wait_down;
73 
74 struct g_hh00 {
75 	struct g_class		*mp;
76 	struct g_provider	*pp;
77 	off_t			size;
78 	int			error;
79 	int			post;
80 };
81 
82 void
83 g_dbg_printf(const char *classname, int lvl, struct bio *bp,
84     const char *format,
85     ...)
86 {
87 #ifndef PRINTF_BUFR_SIZE
88 #define PRINTF_BUFR_SIZE 64
89 #endif
90 	char bufr[PRINTF_BUFR_SIZE];
91 	struct sbuf sb, *sbp __unused;
92 	va_list ap;
93 
94 	sbp = sbuf_new(&sb, bufr, sizeof(bufr), SBUF_FIXEDLEN);
95 	KASSERT(sbp != NULL, ("sbuf_new misused?"));
96 
97 	sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
98 
99 	sbuf_cat(&sb, classname);
100 	if (lvl >= 0)
101 		sbuf_printf(&sb, "[%d]", lvl);
102 
103 	va_start(ap, format);
104 	sbuf_vprintf(&sb, format, ap);
105 	va_end(ap);
106 
107 	if (bp != NULL) {
108 		sbuf_putc(&sb, ' ');
109 		g_format_bio(&sb, bp);
110 	}
111 
112 	/* Terminate the debug line with a single '\n'. */
113 	sbuf_nl_terminate(&sb);
114 
115 	/* Flush line to printf. */
116 	sbuf_finish(&sb);
117 	sbuf_delete(&sb);
118 }
119 
120 /*
121  * This event offers a new class a chance to taste all preexisting providers.
122  */
123 static void
124 g_load_class(void *arg, int flag)
125 {
126 	struct g_hh00 *hh;
127 	struct g_class *mp2, *mp;
128 	struct g_geom *gp;
129 	struct g_provider *pp;
130 
131 	g_topology_assert();
132 	if (flag == EV_CANCEL)	/* XXX: can't happen ? */
133 		return;
134 	if (g_shutdown)
135 		return;
136 
137 	hh = arg;
138 	mp = hh->mp;
139 	hh->error = 0;
140 	if (hh->post) {
141 		g_free(hh);
142 		hh = NULL;
143 	}
144 	g_trace(G_T_TOPOLOGY, "g_load_class(%s)", mp->name);
145 	KASSERT(mp->name != NULL && *mp->name != '\0',
146 	    ("GEOM class has no name"));
147 	LIST_FOREACH(mp2, &g_classes, class) {
148 		if (mp2 == mp) {
149 			printf("The GEOM class %s is already loaded.\n",
150 			    mp2->name);
151 			if (hh != NULL)
152 				hh->error = EEXIST;
153 			return;
154 		} else if (strcmp(mp2->name, mp->name) == 0) {
155 			printf("A GEOM class %s is already loaded.\n",
156 			    mp2->name);
157 			if (hh != NULL)
158 				hh->error = EEXIST;
159 			return;
160 		}
161 	}
162 
163 	LIST_INIT(&mp->geom);
164 	LIST_INSERT_HEAD(&g_classes, mp, class);
165 	if (mp->init != NULL)
166 		mp->init(mp);
167 	if (mp->taste == NULL)
168 		return;
169 	LIST_FOREACH(mp2, &g_classes, class) {
170 		if (mp == mp2)
171 			continue;
172 		LIST_FOREACH(gp, &mp2->geom, geom) {
173 			LIST_FOREACH(pp, &gp->provider, provider) {
174 				mp->taste(mp, pp, 0);
175 				g_topology_assert();
176 			}
177 		}
178 	}
179 }
180 
181 static int
182 g_unload_class(struct g_class *mp)
183 {
184 	struct g_geom *gp;
185 	struct g_provider *pp;
186 	struct g_consumer *cp;
187 	int error;
188 
189 	g_topology_lock();
190 	g_trace(G_T_TOPOLOGY, "g_unload_class(%s)", mp->name);
191 retry:
192 	G_VALID_CLASS(mp);
193 	LIST_FOREACH(gp, &mp->geom, geom) {
194 		/* We refuse to unload if anything is open */
195 		LIST_FOREACH(pp, &gp->provider, provider)
196 			if (pp->acr || pp->acw || pp->ace) {
197 				g_topology_unlock();
198 				return (EBUSY);
199 			}
200 		LIST_FOREACH(cp, &gp->consumer, consumer)
201 			if (cp->acr || cp->acw || cp->ace) {
202 				g_topology_unlock();
203 				return (EBUSY);
204 			}
205 		/* If the geom is withering, wait for it to finish. */
206 		if (gp->flags & G_GEOM_WITHER) {
207 			g_topology_sleep(mp, 1);
208 			goto retry;
209 		}
210 	}
211 
212 	/*
213 	 * We allow unloading if we have no geoms, or a class
214 	 * method we can use to get rid of them.
215 	 */
216 	if (!LIST_EMPTY(&mp->geom) && mp->destroy_geom == NULL) {
217 		g_topology_unlock();
218 		return (EOPNOTSUPP);
219 	}
220 
221 	/* Bar new entries */
222 	mp->taste = NULL;
223 
224 	LIST_FOREACH(gp, &mp->geom, geom) {
225 		error = mp->destroy_geom(NULL, mp, gp);
226 		if (error != 0) {
227 			g_topology_unlock();
228 			return (error);
229 		}
230 	}
231 	/* Wait for withering to finish. */
232 	for (;;) {
233 		gp = LIST_FIRST(&mp->geom);
234 		if (gp == NULL)
235 			break;
236 		KASSERT(gp->flags & G_GEOM_WITHER,
237 		   ("Non-withering geom in class %s", mp->name));
238 		g_topology_sleep(mp, 1);
239 	}
240 	G_VALID_CLASS(mp);
241 	if (mp->fini != NULL)
242 		mp->fini(mp);
243 	LIST_REMOVE(mp, class);
244 	g_topology_unlock();
245 
246 	return (0);
247 }
248 
249 int
250 g_modevent(module_t mod, int type, void *data)
251 {
252 	struct g_hh00 *hh;
253 	int error;
254 	static int g_ignition;
255 	struct g_class *mp;
256 
257 	mp = data;
258 	if (mp->version != G_VERSION) {
259 		printf("GEOM class %s has Wrong version %x\n",
260 		    mp->name, mp->version);
261 		return (EINVAL);
262 	}
263 	if (!g_ignition) {
264 		g_ignition++;
265 		g_init();
266 	}
267 	error = EOPNOTSUPP;
268 	switch (type) {
269 	case MOD_LOAD:
270 		g_trace(G_T_TOPOLOGY, "g_modevent(%s, LOAD)", mp->name);
271 		hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
272 		hh->mp = mp;
273 		/*
274 		 * Once the system is not cold, MOD_LOAD calls will be
275 		 * from the userland and the g_event thread will be able
276 		 * to acknowledge their completion.
277 		 */
278 		if (cold) {
279 			hh->post = 1;
280 			error = g_post_event(g_load_class, hh, M_WAITOK, NULL);
281 		} else {
282 			error = g_waitfor_event(g_load_class, hh, M_WAITOK,
283 			    NULL);
284 			if (error == 0)
285 				error = hh->error;
286 			g_free(hh);
287 		}
288 		break;
289 	case MOD_UNLOAD:
290 		g_trace(G_T_TOPOLOGY, "g_modevent(%s, UNLOAD)", mp->name);
291 		error = g_unload_class(mp);
292 		if (error == 0) {
293 			KASSERT(LIST_EMPTY(&mp->geom),
294 			    ("Unloaded class (%s) still has geom", mp->name));
295 		}
296 		break;
297 	}
298 	return (error);
299 }
300 
301 static void
302 g_retaste_event(void *arg, int flag)
303 {
304 	struct g_class *mp, *mp2;
305 	struct g_geom *gp;
306 	struct g_hh00 *hh;
307 	struct g_provider *pp;
308 	struct g_consumer *cp;
309 
310 	g_topology_assert();
311 	if (flag == EV_CANCEL)  /* XXX: can't happen ? */
312 		return;
313 	if (g_shutdown || g_notaste)
314 		return;
315 
316 	hh = arg;
317 	mp = hh->mp;
318 	hh->error = 0;
319 	if (hh->post) {
320 		g_free(hh);
321 		hh = NULL;
322 	}
323 	g_trace(G_T_TOPOLOGY, "g_retaste(%s)", mp->name);
324 
325 	LIST_FOREACH(mp2, &g_classes, class) {
326 		LIST_FOREACH(gp, &mp2->geom, geom) {
327 			LIST_FOREACH(pp, &gp->provider, provider) {
328 				if (pp->acr || pp->acw || pp->ace)
329 					continue;
330 				LIST_FOREACH(cp, &pp->consumers, consumers) {
331 					if (cp->geom->class == mp &&
332 					    (cp->flags & G_CF_ORPHAN) == 0)
333 						break;
334 				}
335 				if (cp != NULL) {
336 					cp->flags |= G_CF_ORPHAN;
337 					g_wither_geom(cp->geom, ENXIO);
338 				}
339 				mp->taste(mp, pp, 0);
340 				g_topology_assert();
341 			}
342 		}
343 	}
344 }
345 
346 int
347 g_retaste(struct g_class *mp)
348 {
349 	struct g_hh00 *hh;
350 	int error;
351 
352 	if (mp->taste == NULL)
353 		return (EINVAL);
354 
355 	hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
356 	hh->mp = mp;
357 
358 	if (cold) {
359 		hh->post = 1;
360 		error = g_post_event(g_retaste_event, hh, M_WAITOK, NULL);
361 	} else {
362 		error = g_waitfor_event(g_retaste_event, hh, M_WAITOK, NULL);
363 		if (error == 0)
364 			error = hh->error;
365 		g_free(hh);
366 	}
367 
368 	return (error);
369 }
370 
371 struct g_geom *
372 g_new_geomf(struct g_class *mp, const char *fmt, ...)
373 {
374 	struct g_geom *gp;
375 	va_list ap;
376 	struct sbuf *sb;
377 
378 	g_topology_assert();
379 	G_VALID_CLASS(mp);
380 	sb = sbuf_new_auto();
381 	va_start(ap, fmt);
382 	sbuf_vprintf(sb, fmt, ap);
383 	va_end(ap);
384 	sbuf_finish(sb);
385 	gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO);
386 	gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
387 	gp->class = mp;
388 	gp->rank = 1;
389 	LIST_INIT(&gp->consumer);
390 	LIST_INIT(&gp->provider);
391 	LIST_INSERT_HEAD(&mp->geom, gp, geom);
392 	TAILQ_INSERT_HEAD(&geoms, gp, geoms);
393 	strcpy(gp->name, sbuf_data(sb));
394 	sbuf_delete(sb);
395 	/* Fill in defaults from class */
396 	gp->start = mp->start;
397 	gp->spoiled = mp->spoiled;
398 	gp->attrchanged = mp->attrchanged;
399 	gp->providergone = mp->providergone;
400 	gp->dumpconf = mp->dumpconf;
401 	gp->access = mp->access;
402 	gp->orphan = mp->orphan;
403 	gp->ioctl = mp->ioctl;
404 	gp->resize = mp->resize;
405 	return (gp);
406 }
407 
408 void
409 g_destroy_geom(struct g_geom *gp)
410 {
411 
412 	g_topology_assert();
413 	G_VALID_GEOM(gp);
414 	g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
415 	KASSERT(LIST_EMPTY(&gp->consumer),
416 	    ("g_destroy_geom(%s) with consumer(s) [%p]",
417 	    gp->name, LIST_FIRST(&gp->consumer)));
418 	KASSERT(LIST_EMPTY(&gp->provider),
419 	    ("g_destroy_geom(%s) with provider(s) [%p]",
420 	    gp->name, LIST_FIRST(&gp->provider)));
421 	g_cancel_event(gp);
422 	LIST_REMOVE(gp, geom);
423 	TAILQ_REMOVE(&geoms, gp, geoms);
424 	g_free(gp->name);
425 	g_free(gp);
426 }
427 
428 /*
429  * This function is called (repeatedly) until the geom has withered away.
430  */
431 void
432 g_wither_geom(struct g_geom *gp, int error)
433 {
434 	struct g_provider *pp;
435 
436 	g_topology_assert();
437 	G_VALID_GEOM(gp);
438 	g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name);
439 	if (!(gp->flags & G_GEOM_WITHER)) {
440 		gp->flags |= G_GEOM_WITHER;
441 		LIST_FOREACH(pp, &gp->provider, provider)
442 			if (!(pp->flags & G_PF_ORPHAN))
443 				g_orphan_provider(pp, error);
444 	}
445 	g_do_wither();
446 }
447 
448 /*
449  * Convenience function to destroy a particular provider.
450  */
451 void
452 g_wither_provider(struct g_provider *pp, int error)
453 {
454 
455 	pp->flags |= G_PF_WITHER;
456 	if (!(pp->flags & G_PF_ORPHAN))
457 		g_orphan_provider(pp, error);
458 }
459 
460 /*
461  * This function is called (repeatedly) until the has withered away.
462  */
463 void
464 g_wither_geom_close(struct g_geom *gp, int error)
465 {
466 	struct g_consumer *cp;
467 
468 	g_topology_assert();
469 	G_VALID_GEOM(gp);
470 	g_trace(G_T_TOPOLOGY, "g_wither_geom_close(%p(%s))", gp, gp->name);
471 	LIST_FOREACH(cp, &gp->consumer, consumer)
472 		if (cp->acr || cp->acw || cp->ace)
473 			g_access(cp, -cp->acr, -cp->acw, -cp->ace);
474 	g_wither_geom(gp, error);
475 }
476 
477 /*
478  * This function is called (repeatedly) until we cant wash away more
479  * withered bits at present.
480  */
481 void
482 g_wither_washer(void)
483 {
484 	struct g_class *mp;
485 	struct g_geom *gp, *gp2;
486 	struct g_provider *pp, *pp2;
487 	struct g_consumer *cp, *cp2;
488 
489 	g_topology_assert();
490 	LIST_FOREACH(mp, &g_classes, class) {
491 		LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
492 			LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
493 				if (!(pp->flags & G_PF_WITHER))
494 					continue;
495 				if (LIST_EMPTY(&pp->consumers))
496 					g_destroy_provider(pp);
497 			}
498 			if (!(gp->flags & G_GEOM_WITHER))
499 				continue;
500 			LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
501 				if (LIST_EMPTY(&pp->consumers))
502 					g_destroy_provider(pp);
503 			}
504 			LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp2) {
505 				if (cp->acr || cp->acw || cp->ace)
506 					continue;
507 				if (cp->provider != NULL)
508 					g_detach(cp);
509 				g_destroy_consumer(cp);
510 			}
511 			if (LIST_EMPTY(&gp->provider) &&
512 			    LIST_EMPTY(&gp->consumer))
513 				g_destroy_geom(gp);
514 		}
515 	}
516 }
517 
518 struct g_consumer *
519 g_new_consumer(struct g_geom *gp)
520 {
521 	struct g_consumer *cp;
522 
523 	g_topology_assert();
524 	G_VALID_GEOM(gp);
525 	KASSERT(!(gp->flags & G_GEOM_WITHER),
526 	    ("g_new_consumer on WITHERing geom(%s) (class %s)",
527 	    gp->name, gp->class->name));
528 	KASSERT(gp->orphan != NULL,
529 	    ("g_new_consumer on geom(%s) (class %s) without orphan",
530 	    gp->name, gp->class->name));
531 
532 	cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO);
533 	cp->geom = gp;
534 	cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED,
535 	    DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
536 	LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
537 	return(cp);
538 }
539 
540 void
541 g_destroy_consumer(struct g_consumer *cp)
542 {
543 	struct g_geom *gp;
544 
545 	g_topology_assert();
546 	G_VALID_CONSUMER(cp);
547 	g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
548 	KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
549 	KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
550 	KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
551 	KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
552 	g_cancel_event(cp);
553 	gp = cp->geom;
554 	LIST_REMOVE(cp, consumer);
555 	devstat_remove_entry(cp->stat);
556 	g_free(cp);
557 	if (gp->flags & G_GEOM_WITHER)
558 		g_do_wither();
559 }
560 
561 static void
562 g_new_provider_event(void *arg, int flag)
563 {
564 	struct g_class *mp;
565 	struct g_provider *pp;
566 	struct g_consumer *cp, *next_cp;
567 
568 	g_topology_assert();
569 	if (flag == EV_CANCEL)
570 		return;
571 	if (g_shutdown)
572 		return;
573 	pp = arg;
574 	G_VALID_PROVIDER(pp);
575 	if ((pp->flags & G_PF_WITHER) != 0)
576 		return;
577 	LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, next_cp) {
578 		if ((cp->flags & G_CF_ORPHAN) == 0 &&
579 		    cp->geom->attrchanged != NULL)
580 			cp->geom->attrchanged(cp, "GEOM::media");
581 	}
582 	if (g_notaste)
583 		return;
584 	LIST_FOREACH(mp, &g_classes, class) {
585 		if (mp->taste == NULL)
586 			continue;
587 		LIST_FOREACH(cp, &pp->consumers, consumers)
588 			if (cp->geom->class == mp &&
589 			    (cp->flags & G_CF_ORPHAN) == 0)
590 				break;
591 		if (cp != NULL)
592 			continue;
593 		mp->taste(mp, pp, 0);
594 		g_topology_assert();
595 	}
596 }
597 
598 struct g_provider *
599 g_new_providerf(struct g_geom *gp, const char *fmt, ...)
600 {
601 	struct g_provider *pp;
602 	struct sbuf *sb;
603 	va_list ap;
604 
605 	g_topology_assert();
606 	G_VALID_GEOM(gp);
607 	KASSERT(gp->access != NULL,
608 	    ("new provider on geom(%s) without ->access (class %s)",
609 	    gp->name, gp->class->name));
610 	KASSERT(gp->start != NULL,
611 	    ("new provider on geom(%s) without ->start (class %s)",
612 	    gp->name, gp->class->name));
613 	KASSERT(!(gp->flags & G_GEOM_WITHER),
614 	    ("new provider on WITHERing geom(%s) (class %s)",
615 	    gp->name, gp->class->name));
616 	sb = sbuf_new_auto();
617 	va_start(ap, fmt);
618 	sbuf_vprintf(sb, fmt, ap);
619 	va_end(ap);
620 	sbuf_finish(sb);
621 	pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
622 	pp->name = (char *)(pp + 1);
623 	strcpy(pp->name, sbuf_data(sb));
624 	sbuf_delete(sb);
625 	LIST_INIT(&pp->consumers);
626 	LIST_INIT(&pp->aliases);
627 	pp->error = ENXIO;
628 	pp->geom = gp;
629 	pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED,
630 	    DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
631 	LIST_INSERT_HEAD(&gp->provider, pp, provider);
632 	g_post_event(g_new_provider_event, pp, M_WAITOK, pp, gp, NULL);
633 	return (pp);
634 }
635 
636 void
637 g_provider_add_alias(struct g_provider *pp, const char *fmt, ...)
638 {
639 	struct sbuf *sb;
640 	struct g_geom_alias *gap;
641 	va_list ap;
642 
643 	/*
644 	 * Generate the alias string and save it in the list.
645 	 */
646 	sb = sbuf_new_auto();
647 	va_start(ap, fmt);
648 	sbuf_vprintf(sb, fmt, ap);
649 	va_end(ap);
650 	sbuf_finish(sb);
651 
652 	LIST_FOREACH(gap, &pp->aliases, ga_next) {
653 		if (strcmp(gap->ga_alias, sbuf_data(sb)) != 0)
654 			continue;
655 		/* Don't re-add the same alias. */
656 		sbuf_delete(sb);
657 		return;
658 	}
659 
660 	gap = g_malloc(sizeof(*gap) + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
661 	memcpy((char *)(gap + 1), sbuf_data(sb), sbuf_len(sb));
662 	sbuf_delete(sb);
663 	gap->ga_alias = (const char *)(gap + 1);
664 	LIST_INSERT_HEAD(&pp->aliases, gap, ga_next);
665 }
666 
667 void
668 g_error_provider(struct g_provider *pp, int error)
669 {
670 
671 	/* G_VALID_PROVIDER(pp);  We may not have g_topology */
672 	pp->error = error;
673 }
674 
675 static void
676 g_resize_provider_event(void *arg, int flag)
677 {
678 	struct g_hh00 *hh;
679 	struct g_class *mp;
680 	struct g_geom *gp;
681 	struct g_provider *pp;
682 	struct g_consumer *cp, *cp2;
683 	off_t size;
684 
685 	g_topology_assert();
686 	if (g_shutdown)
687 		return;
688 
689 	hh = arg;
690 	pp = hh->pp;
691 	size = hh->size;
692 	g_free(hh);
693 
694 	G_VALID_PROVIDER(pp);
695 	KASSERT(!(pp->flags & G_PF_WITHER),
696 	    ("g_resize_provider_event but withered"));
697 	g_trace(G_T_TOPOLOGY, "g_resize_provider_event(%p)", pp);
698 
699 	LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, cp2) {
700 		gp = cp->geom;
701 		if (gp->resize == NULL && size < pp->mediasize) {
702 			/*
703 			 * XXX: g_dev_orphan method does deferred destroying
704 			 * and it is possible, that other event could already
705 			 * call the orphan method. Check consumer's flags to
706 			 * do not schedule it twice.
707 			 */
708 			if (cp->flags & G_CF_ORPHAN)
709 				continue;
710 			cp->flags |= G_CF_ORPHAN;
711 			cp->geom->orphan(cp);
712 		}
713 	}
714 
715 	pp->mediasize = size;
716 
717 	LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, cp2) {
718 		gp = cp->geom;
719 		if ((gp->flags & G_GEOM_WITHER) == 0 && gp->resize != NULL)
720 			gp->resize(cp);
721 	}
722 
723 	/*
724 	 * After resizing, the previously invalid GEOM class metadata
725 	 * might become valid.  This means we should retaste.
726 	 */
727 	LIST_FOREACH(mp, &g_classes, class) {
728 		if (mp->taste == NULL)
729 			continue;
730 		LIST_FOREACH(cp, &pp->consumers, consumers)
731 			if (cp->geom->class == mp &&
732 			    (cp->flags & G_CF_ORPHAN) == 0)
733 				break;
734 		if (cp != NULL)
735 			continue;
736 		mp->taste(mp, pp, 0);
737 		g_topology_assert();
738 	}
739 }
740 
741 void
742 g_resize_provider(struct g_provider *pp, off_t size)
743 {
744 	struct g_hh00 *hh;
745 
746 	G_VALID_PROVIDER(pp);
747 	if (pp->flags & G_PF_WITHER)
748 		return;
749 
750 	if (size == pp->mediasize)
751 		return;
752 
753 	hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
754 	hh->pp = pp;
755 	hh->size = size;
756 	g_post_event(g_resize_provider_event, hh, M_WAITOK, NULL);
757 }
758 
759 struct g_provider *
760 g_provider_by_name(char const *arg)
761 {
762 	struct g_class *cp;
763 	struct g_geom *gp;
764 	struct g_provider *pp, *wpp;
765 
766 	if (strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
767 		arg += sizeof(_PATH_DEV) - 1;
768 
769 	wpp = NULL;
770 	LIST_FOREACH(cp, &g_classes, class) {
771 		LIST_FOREACH(gp, &cp->geom, geom) {
772 			LIST_FOREACH(pp, &gp->provider, provider) {
773 				if (strcmp(arg, pp->name) != 0)
774 					continue;
775 				if ((gp->flags & G_GEOM_WITHER) == 0 &&
776 				    (pp->flags & G_PF_WITHER) == 0)
777 					return (pp);
778 				else
779 					wpp = pp;
780 			}
781 		}
782 	}
783 
784 	return (wpp);
785 }
786 
787 void
788 g_destroy_provider(struct g_provider *pp)
789 {
790 	struct g_geom *gp;
791 	struct g_geom_alias *gap, *gaptmp;
792 
793 	g_topology_assert();
794 	G_VALID_PROVIDER(pp);
795 	KASSERT(LIST_EMPTY(&pp->consumers),
796 	    ("g_destroy_provider but attached"));
797 	KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
798 	KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
799 	KASSERT (pp->ace == 0, ("g_destroy_provider with ace"));
800 	g_cancel_event(pp);
801 	LIST_REMOVE(pp, provider);
802 	gp = pp->geom;
803 	devstat_remove_entry(pp->stat);
804 	/*
805 	 * If a callback was provided, send notification that the provider
806 	 * is now gone.
807 	 */
808 	if (gp->providergone != NULL)
809 		gp->providergone(pp);
810 	LIST_FOREACH_SAFE(gap, &pp->aliases, ga_next, gaptmp)
811 		g_free(gap);
812 	g_free(pp);
813 	if ((gp->flags & G_GEOM_WITHER))
814 		g_do_wither();
815 }
816 
817 /*
818  * We keep the "geoms" list sorted by topological order (== increasing
819  * numerical rank) at all times.
820  * When an attach is done, the attaching geoms rank is invalidated
821  * and it is moved to the tail of the list.
822  * All geoms later in the sequence has their ranks reevaluated in
823  * sequence.  If we cannot assign rank to a geom because it's
824  * prerequisites do not have rank, we move that element to the tail
825  * of the sequence with invalid rank as well.
826  * At some point we encounter our original geom and if we stil fail
827  * to assign it a rank, there must be a loop and we fail back to
828  * g_attach() which detach again and calls redo_rank again
829  * to fix up the damage.
830  * It would be much simpler code wise to do it recursively, but we
831  * can't risk that on the kernel stack.
832  */
833 
834 static int
835 redo_rank(struct g_geom *gp)
836 {
837 	struct g_consumer *cp;
838 	struct g_geom *gp1, *gp2;
839 	int n, m;
840 
841 	g_topology_assert();
842 	G_VALID_GEOM(gp);
843 
844 	/* Invalidate this geoms rank and move it to the tail */
845 	gp1 = TAILQ_NEXT(gp, geoms);
846 	if (gp1 != NULL) {
847 		gp->rank = 0;
848 		TAILQ_REMOVE(&geoms, gp, geoms);
849 		TAILQ_INSERT_TAIL(&geoms, gp, geoms);
850 	} else {
851 		gp1 = gp;
852 	}
853 
854 	/* re-rank the rest of the sequence */
855 	for (; gp1 != NULL; gp1 = gp2) {
856 		gp1->rank = 0;
857 		m = 1;
858 		LIST_FOREACH(cp, &gp1->consumer, consumer) {
859 			if (cp->provider == NULL)
860 				continue;
861 			n = cp->provider->geom->rank;
862 			if (n == 0) {
863 				m = 0;
864 				break;
865 			} else if (n >= m)
866 				m = n + 1;
867 		}
868 		gp1->rank = m;
869 		gp2 = TAILQ_NEXT(gp1, geoms);
870 
871 		/* got a rank, moving on */
872 		if (m != 0)
873 			continue;
874 
875 		/* no rank to original geom means loop */
876 		if (gp == gp1)
877 			return (ELOOP);
878 
879 		/* no rank, put it at the end move on */
880 		TAILQ_REMOVE(&geoms, gp1, geoms);
881 		TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
882 	}
883 	return (0);
884 }
885 
886 int
887 g_attach(struct g_consumer *cp, struct g_provider *pp)
888 {
889 	int error;
890 
891 	g_topology_assert();
892 	G_VALID_CONSUMER(cp);
893 	G_VALID_PROVIDER(pp);
894 	g_trace(G_T_TOPOLOGY, "g_attach(%p, %p)", cp, pp);
895 	KASSERT(cp->provider == NULL, ("attach but attached"));
896 	if ((pp->flags & (G_PF_ORPHAN | G_PF_WITHER)) != 0)
897 		return (ENXIO);
898 	cp->provider = pp;
899 	cp->flags &= ~G_CF_ORPHAN;
900 	LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
901 	error = redo_rank(cp->geom);
902 	if (error) {
903 		LIST_REMOVE(cp, consumers);
904 		cp->provider = NULL;
905 		redo_rank(cp->geom);
906 	}
907 	return (error);
908 }
909 
910 void
911 g_detach(struct g_consumer *cp)
912 {
913 	struct g_provider *pp;
914 
915 	g_topology_assert();
916 	G_VALID_CONSUMER(cp);
917 	g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp);
918 	KASSERT(cp->provider != NULL, ("detach but not attached"));
919 	KASSERT(cp->acr == 0, ("detach but nonzero acr"));
920 	KASSERT(cp->acw == 0, ("detach but nonzero acw"));
921 	KASSERT(cp->ace == 0, ("detach but nonzero ace"));
922 	KASSERT(cp->nstart == cp->nend,
923 	    ("detach with active requests"));
924 	pp = cp->provider;
925 	LIST_REMOVE(cp, consumers);
926 	cp->provider = NULL;
927 	if ((cp->geom->flags & G_GEOM_WITHER) ||
928 	    (pp->geom->flags & G_GEOM_WITHER) ||
929 	    (pp->flags & G_PF_WITHER))
930 		g_do_wither();
931 	redo_rank(cp->geom);
932 }
933 
934 /*
935  * g_access()
936  *
937  * Access-check with delta values.  The question asked is "can provider
938  * "cp" change the access counters by the relative amounts dc[rwe] ?"
939  */
940 
941 int
942 g_access(struct g_consumer *cp, int dcr, int dcw, int dce)
943 {
944 	struct g_provider *pp;
945 	struct g_geom *gp;
946 	int pw, pe;
947 #ifdef INVARIANTS
948 	int sr, sw, se;
949 #endif
950 	int error;
951 
952 	g_topology_assert();
953 	G_VALID_CONSUMER(cp);
954 	pp = cp->provider;
955 	KASSERT(pp != NULL, ("access but not attached"));
956 	G_VALID_PROVIDER(pp);
957 	gp = pp->geom;
958 
959 	g_trace(G_T_ACCESS, "g_access(%p(%s), %d, %d, %d)",
960 	    cp, pp->name, dcr, dcw, dce);
961 
962 	KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
963 	KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
964 	KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
965 	KASSERT(dcr != 0 || dcw != 0 || dce != 0, ("NOP access request"));
966 	KASSERT(cp->acr + dcr != 0 || cp->acw + dcw != 0 ||
967 	    cp->ace + dce != 0 || cp->nstart == cp->nend,
968 	    ("Last close with active requests"));
969 	KASSERT(gp->access != NULL, ("NULL geom->access"));
970 
971 	/*
972 	 * If our class cares about being spoiled, and we have been, we
973 	 * are probably just ahead of the event telling us that.  Fail
974 	 * now rather than having to unravel this later.
975 	 */
976 	if (cp->geom->spoiled != NULL && (cp->flags & G_CF_SPOILED) &&
977 	    (dcr > 0 || dcw > 0 || dce > 0))
978 		return (ENXIO);
979 
980 	/*
981 	 * A number of GEOM classes either need to perform an I/O on the first
982 	 * open or to acquire a different subsystem's lock.  To do that they
983 	 * may have to drop the topology lock.
984 	 * Other GEOM classes perform special actions when opening a lower rank
985 	 * geom for the first time.  As a result, more than one thread may
986 	 * end up performing the special actions.
987 	 * So, we prevent concurrent "first" opens by marking the consumer with
988 	 * special flag.
989 	 *
990 	 * Note that if the geom's access method never drops the topology lock,
991 	 * then we will never see G_GEOM_IN_ACCESS here.
992 	 */
993 	while ((gp->flags & G_GEOM_IN_ACCESS) != 0) {
994 		g_trace(G_T_ACCESS,
995 		    "%s: race on geom %s via provider %s and consumer of %s",
996 		    __func__, gp->name, pp->name, cp->geom->name);
997 		gp->flags |= G_GEOM_ACCESS_WAIT;
998 		g_topology_sleep(gp, 0);
999 	}
1000 
1001 	/*
1002 	 * Figure out what counts the provider would have had, if this
1003 	 * consumer had (r0w0e0) at this time.
1004 	 */
1005 	pw = pp->acw - cp->acw;
1006 	pe = pp->ace - cp->ace;
1007 
1008 	g_trace(G_T_ACCESS,
1009     "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
1010 	    dcr, dcw, dce,
1011 	    cp->acr, cp->acw, cp->ace,
1012 	    pp->acr, pp->acw, pp->ace,
1013 	    pp, pp->name);
1014 
1015 	/* If foot-shooting is enabled, any open on rank#1 is OK */
1016 	if ((g_debugflags & G_F_FOOTSHOOTING) && gp->rank == 1)
1017 		;
1018 	/* If we try exclusive but already write: fail */
1019 	else if (dce > 0 && pw > 0)
1020 		return (EPERM);
1021 	/* If we try write but already exclusive: fail */
1022 	else if (dcw > 0 && pe > 0)
1023 		return (EPERM);
1024 	/* If we try to open more but provider is error'ed: fail */
1025 	else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0) {
1026 		printf("%s(%d): provider %s has error %d set\n",
1027 		    __func__, __LINE__, pp->name, pp->error);
1028 		return (pp->error);
1029 	}
1030 
1031 	/* Ok then... */
1032 
1033 #ifdef INVARIANTS
1034 	sr = cp->acr;
1035 	sw = cp->acw;
1036 	se = cp->ace;
1037 #endif
1038 	gp->flags |= G_GEOM_IN_ACCESS;
1039 	error = gp->access(pp, dcr, dcw, dce);
1040 	KASSERT(dcr > 0 || dcw > 0 || dce > 0 || error == 0,
1041 	    ("Geom provider %s::%s dcr=%d dcw=%d dce=%d error=%d failed "
1042 	    "closing ->access()", gp->class->name, pp->name, dcr, dcw,
1043 	    dce, error));
1044 
1045 	g_topology_assert();
1046 	gp->flags &= ~G_GEOM_IN_ACCESS;
1047 	KASSERT(cp->acr == sr && cp->acw == sw && cp->ace == se,
1048 	    ("Access counts changed during geom->access"));
1049 	if ((gp->flags & G_GEOM_ACCESS_WAIT) != 0) {
1050 		gp->flags &= ~G_GEOM_ACCESS_WAIT;
1051 		wakeup(gp);
1052 	}
1053 
1054 	if (!error) {
1055 		/*
1056 		 * If we open first write, spoil any partner consumers.
1057 		 * If we close last write and provider is not errored,
1058 		 * trigger re-taste.
1059 		 */
1060 		if (pp->acw == 0 && dcw != 0)
1061 			g_spoil(pp, cp);
1062 		else if (pp->acw != 0 && pp->acw == -dcw && pp->error == 0 &&
1063 		    !(gp->flags & G_GEOM_WITHER))
1064 			g_post_event(g_new_provider_event, pp, M_WAITOK,
1065 			    pp, NULL);
1066 
1067 		pp->acr += dcr;
1068 		pp->acw += dcw;
1069 		pp->ace += dce;
1070 		cp->acr += dcr;
1071 		cp->acw += dcw;
1072 		cp->ace += dce;
1073 		if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)
1074 			KASSERT(pp->sectorsize > 0,
1075 			    ("Provider %s lacks sectorsize", pp->name));
1076 		if ((cp->geom->flags & G_GEOM_WITHER) &&
1077 		    cp->acr == 0 && cp->acw == 0 && cp->ace == 0)
1078 			g_do_wither();
1079 	}
1080 	return (error);
1081 }
1082 
1083 int
1084 g_handleattr_int(struct bio *bp, const char *attribute, int val)
1085 {
1086 
1087 	return (g_handleattr(bp, attribute, &val, sizeof val));
1088 }
1089 
1090 int
1091 g_handleattr_uint16_t(struct bio *bp, const char *attribute, uint16_t val)
1092 {
1093 
1094 	return (g_handleattr(bp, attribute, &val, sizeof val));
1095 }
1096 
1097 int
1098 g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val)
1099 {
1100 
1101 	return (g_handleattr(bp, attribute, &val, sizeof val));
1102 }
1103 
1104 int
1105 g_handleattr_str(struct bio *bp, const char *attribute, const char *str)
1106 {
1107 
1108 	return (g_handleattr(bp, attribute, str, 0));
1109 }
1110 
1111 int
1112 g_handleattr(struct bio *bp, const char *attribute, const void *val, int len)
1113 {
1114 	int error = 0;
1115 
1116 	if (strcmp(bp->bio_attribute, attribute))
1117 		return (0);
1118 	if (len == 0) {
1119 		bzero(bp->bio_data, bp->bio_length);
1120 		if (strlcpy(bp->bio_data, val, bp->bio_length) >=
1121 		    bp->bio_length) {
1122 			printf("%s: %s %s bio_length %jd strlen %zu -> EFAULT\n",
1123 			    __func__, bp->bio_to->name, attribute,
1124 			    (intmax_t)bp->bio_length, strlen(val));
1125 			error = EFAULT;
1126 		}
1127 	} else if (bp->bio_length == len) {
1128 		bcopy(val, bp->bio_data, len);
1129 	} else {
1130 		printf("%s: %s %s bio_length %jd len %d -> EFAULT\n", __func__,
1131 		    bp->bio_to->name, attribute, (intmax_t)bp->bio_length, len);
1132 		error = EFAULT;
1133 	}
1134 	if (error == 0)
1135 		bp->bio_completed = bp->bio_length;
1136 	g_io_deliver(bp, error);
1137 	return (1);
1138 }
1139 
1140 int
1141 g_std_access(struct g_provider *pp,
1142 	int dr __unused, int dw __unused, int de __unused)
1143 {
1144 
1145 	g_topology_assert();
1146 	G_VALID_PROVIDER(pp);
1147         return (0);
1148 }
1149 
1150 void
1151 g_std_done(struct bio *bp)
1152 {
1153 	struct bio *bp2;
1154 
1155 	bp2 = bp->bio_parent;
1156 	if (bp2->bio_error == 0)
1157 		bp2->bio_error = bp->bio_error;
1158 	bp2->bio_completed += bp->bio_completed;
1159 	g_destroy_bio(bp);
1160 	bp2->bio_inbed++;
1161 	if (bp2->bio_children == bp2->bio_inbed) {
1162 		if (bp2->bio_cmd == BIO_SPEEDUP)
1163 			bp2->bio_completed = bp2->bio_length;
1164 		g_io_deliver(bp2, bp2->bio_error);
1165 	}
1166 }
1167 
1168 /* XXX: maybe this is only g_slice_spoiled */
1169 
1170 void
1171 g_std_spoiled(struct g_consumer *cp)
1172 {
1173 	struct g_geom *gp;
1174 	struct g_provider *pp;
1175 
1176 	g_topology_assert();
1177 	G_VALID_CONSUMER(cp);
1178 	g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
1179 	cp->flags |= G_CF_ORPHAN;
1180 	g_detach(cp);
1181 	gp = cp->geom;
1182 	LIST_FOREACH(pp, &gp->provider, provider)
1183 		g_orphan_provider(pp, ENXIO);
1184 	g_destroy_consumer(cp);
1185 	if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
1186 		g_destroy_geom(gp);
1187 	else
1188 		gp->flags |= G_GEOM_WITHER;
1189 }
1190 
1191 /*
1192  * Spoiling happens when a provider is opened for writing, but consumers
1193  * which are configured by in-band data are attached (slicers for instance).
1194  * Since the write might potentially change the in-band data, such consumers
1195  * need to re-evaluate their existence after the writing session closes.
1196  * We do this by (offering to) tear them down when the open for write happens
1197  * in return for a re-taste when it closes again.
1198  * Together with the fact that such consumers grab an 'e' bit whenever they
1199  * are open, regardless of mode, this ends up DTRT.
1200  */
1201 
1202 static void
1203 g_spoil_event(void *arg, int flag)
1204 {
1205 	struct g_provider *pp;
1206 	struct g_consumer *cp, *cp2;
1207 
1208 	g_topology_assert();
1209 	if (flag == EV_CANCEL)
1210 		return;
1211 	pp = arg;
1212 	G_VALID_PROVIDER(pp);
1213 	g_trace(G_T_TOPOLOGY, "%s %p(%s:%s:%s)", __func__, pp,
1214 	    pp->geom->class->name, pp->geom->name, pp->name);
1215 	for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) {
1216 		cp2 = LIST_NEXT(cp, consumers);
1217 		if ((cp->flags & G_CF_SPOILED) == 0)
1218 			continue;
1219 		cp->flags &= ~G_CF_SPOILED;
1220 		if (cp->geom->spoiled == NULL)
1221 			continue;
1222 		cp->geom->spoiled(cp);
1223 		g_topology_assert();
1224 	}
1225 }
1226 
1227 void
1228 g_spoil(struct g_provider *pp, struct g_consumer *cp)
1229 {
1230 	struct g_consumer *cp2;
1231 
1232 	g_topology_assert();
1233 	G_VALID_PROVIDER(pp);
1234 	G_VALID_CONSUMER(cp);
1235 
1236 	LIST_FOREACH(cp2, &pp->consumers, consumers) {
1237 		if (cp2 == cp)
1238 			continue;
1239 /*
1240 		KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
1241 		KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
1242 */
1243 		KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
1244 		cp2->flags |= G_CF_SPOILED;
1245 	}
1246 	g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL);
1247 }
1248 
1249 static void
1250 g_media_changed_event(void *arg, int flag)
1251 {
1252 	struct g_provider *pp;
1253 	int retaste;
1254 
1255 	g_topology_assert();
1256 	if (flag == EV_CANCEL)
1257 		return;
1258 	pp = arg;
1259 	G_VALID_PROVIDER(pp);
1260 
1261 	/*
1262 	 * If provider was not open for writing, queue retaste after spoiling.
1263 	 * If it was, retaste will happen automatically on close.
1264 	 */
1265 	retaste = (pp->acw == 0 && pp->error == 0 &&
1266 	    !(pp->geom->flags & G_GEOM_WITHER));
1267 	g_spoil_event(arg, flag);
1268 	if (retaste)
1269 		g_post_event(g_new_provider_event, pp, M_WAITOK, pp, NULL);
1270 }
1271 
1272 int
1273 g_media_changed(struct g_provider *pp, int flag)
1274 {
1275 	struct g_consumer *cp;
1276 
1277 	LIST_FOREACH(cp, &pp->consumers, consumers)
1278 		cp->flags |= G_CF_SPOILED;
1279 	return (g_post_event(g_media_changed_event, pp, flag, pp, NULL));
1280 }
1281 
1282 int
1283 g_media_gone(struct g_provider *pp, int flag)
1284 {
1285 	struct g_consumer *cp;
1286 
1287 	LIST_FOREACH(cp, &pp->consumers, consumers)
1288 		cp->flags |= G_CF_SPOILED;
1289 	return (g_post_event(g_spoil_event, pp, flag, pp, NULL));
1290 }
1291 
1292 int
1293 g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len)
1294 {
1295 	int error, i;
1296 
1297 	i = len;
1298 	error = g_io_getattr(attr, cp, &i, var);
1299 	if (error)
1300 		return (error);
1301 	if (i != len)
1302 		return (EINVAL);
1303 	return (0);
1304 }
1305 
1306 static int
1307 g_get_device_prefix_len(const char *name)
1308 {
1309 	int len;
1310 
1311 	if (strncmp(name, "ada", 3) == 0)
1312 		len = 3;
1313 	else if (strncmp(name, "ad", 2) == 0)
1314 		len = 2;
1315 	else
1316 		return (0);
1317 	if (name[len] < '0' || name[len] > '9')
1318 		return (0);
1319 	do {
1320 		len++;
1321 	} while (name[len] >= '0' && name[len] <= '9');
1322 	return (len);
1323 }
1324 
1325 int
1326 g_compare_names(const char *namea, const char *nameb)
1327 {
1328 	int deva, devb;
1329 
1330 	if (strcmp(namea, nameb) == 0)
1331 		return (1);
1332 	deva = g_get_device_prefix_len(namea);
1333 	if (deva == 0)
1334 		return (0);
1335 	devb = g_get_device_prefix_len(nameb);
1336 	if (devb == 0)
1337 		return (0);
1338 	if (strcmp(namea + deva, nameb + devb) == 0)
1339 		return (1);
1340 	return (0);
1341 }
1342 
1343 #if defined(DIAGNOSTIC) || defined(DDB)
1344 /*
1345  * This function walks the mesh and returns a non-zero integer if it
1346  * finds the argument pointer is an object. The return value indicates
1347  * which type of object it is believed to be. If topology is not locked,
1348  * this function is potentially dangerous, but we don't assert that the
1349  * topology lock is held when called from debugger.
1350  */
1351 int
1352 g_valid_obj(void const *ptr)
1353 {
1354 	struct g_class *mp;
1355 	struct g_geom *gp;
1356 	struct g_consumer *cp;
1357 	struct g_provider *pp;
1358 
1359 #ifdef KDB
1360 	if (kdb_active == 0)
1361 #endif
1362 		g_topology_assert();
1363 
1364 	LIST_FOREACH(mp, &g_classes, class) {
1365 		if (ptr == mp)
1366 			return (1);
1367 		LIST_FOREACH(gp, &mp->geom, geom) {
1368 			if (ptr == gp)
1369 				return (2);
1370 			LIST_FOREACH(cp, &gp->consumer, consumer)
1371 				if (ptr == cp)
1372 					return (3);
1373 			LIST_FOREACH(pp, &gp->provider, provider)
1374 				if (ptr == pp)
1375 					return (4);
1376 		}
1377 	}
1378 	return(0);
1379 }
1380 #endif
1381 
1382 #ifdef DDB
1383 
1384 #define	gprintf(...)	do {						\
1385 	db_printf("%*s", indent, "");					\
1386 	db_printf(__VA_ARGS__);						\
1387 } while (0)
1388 #define	gprintln(...)	do {						\
1389 	gprintf(__VA_ARGS__);						\
1390 	db_printf("\n");						\
1391 } while (0)
1392 
1393 #define	ADDFLAG(obj, flag, sflag)	do {				\
1394 	if ((obj)->flags & (flag)) {					\
1395 		if (comma)						\
1396 			strlcat(str, ",", size);			\
1397 		strlcat(str, (sflag), size);				\
1398 		comma = 1;						\
1399 	}								\
1400 } while (0)
1401 
1402 static char *
1403 provider_flags_to_string(struct g_provider *pp, char *str, size_t size)
1404 {
1405 	int comma = 0;
1406 
1407 	bzero(str, size);
1408 	if (pp->flags == 0) {
1409 		strlcpy(str, "NONE", size);
1410 		return (str);
1411 	}
1412 	ADDFLAG(pp, G_PF_WITHER, "G_PF_WITHER");
1413 	ADDFLAG(pp, G_PF_ORPHAN, "G_PF_ORPHAN");
1414 	return (str);
1415 }
1416 
1417 static char *
1418 geom_flags_to_string(struct g_geom *gp, char *str, size_t size)
1419 {
1420 	int comma = 0;
1421 
1422 	bzero(str, size);
1423 	if (gp->flags == 0) {
1424 		strlcpy(str, "NONE", size);
1425 		return (str);
1426 	}
1427 	ADDFLAG(gp, G_GEOM_WITHER, "G_GEOM_WITHER");
1428 	return (str);
1429 }
1430 static void
1431 db_show_geom_consumer(int indent, struct g_consumer *cp)
1432 {
1433 
1434 	if (indent == 0) {
1435 		gprintln("consumer: %p", cp);
1436 		gprintln("  class:    %s (%p)", cp->geom->class->name,
1437 		    cp->geom->class);
1438 		gprintln("  geom:     %s (%p)", cp->geom->name, cp->geom);
1439 		if (cp->provider == NULL)
1440 			gprintln("  provider: none");
1441 		else {
1442 			gprintln("  provider: %s (%p)", cp->provider->name,
1443 			    cp->provider);
1444 		}
1445 		gprintln("  access:   r%dw%de%d", cp->acr, cp->acw, cp->ace);
1446 		gprintln("  flags:    0x%04x", cp->flags);
1447 #ifdef INVARIANTS
1448 		gprintln("  nstart:   %u", cp->nstart);
1449 		gprintln("  nend:     %u", cp->nend);
1450 #endif
1451 	} else {
1452 		gprintf("consumer: %p (%s), access=r%dw%de%d", cp,
1453 		    cp->provider != NULL ? cp->provider->name : "none",
1454 		    cp->acr, cp->acw, cp->ace);
1455 		if (cp->flags)
1456 			db_printf(", flags=0x%04x", cp->flags);
1457 		db_printf("\n");
1458 	}
1459 }
1460 
1461 static void
1462 db_show_geom_provider(int indent, struct g_provider *pp)
1463 {
1464 	struct g_consumer *cp;
1465 	char flags[64];
1466 
1467 	if (indent == 0) {
1468 		gprintln("provider: %s (%p)", pp->name, pp);
1469 		gprintln("  class:        %s (%p)", pp->geom->class->name,
1470 		    pp->geom->class);
1471 		gprintln("  geom:         %s (%p)", pp->geom->name, pp->geom);
1472 		gprintln("  mediasize:    %jd", (intmax_t)pp->mediasize);
1473 		gprintln("  sectorsize:   %u", pp->sectorsize);
1474 		gprintln("  stripesize:   %ju", (uintmax_t)pp->stripesize);
1475 		gprintln("  stripeoffset: %ju", (uintmax_t)pp->stripeoffset);
1476 		gprintln("  access:       r%dw%de%d", pp->acr, pp->acw,
1477 		    pp->ace);
1478 		gprintln("  flags:        %s (0x%04x)",
1479 		    provider_flags_to_string(pp, flags, sizeof(flags)),
1480 		    pp->flags);
1481 		gprintln("  error:        %d", pp->error);
1482 		if (LIST_EMPTY(&pp->consumers))
1483 			gprintln("  consumers:    none");
1484 	} else {
1485 		gprintf("provider: %s (%p), access=r%dw%de%d",
1486 		    pp->name, pp, pp->acr, pp->acw, pp->ace);
1487 		if (pp->flags != 0) {
1488 			db_printf(", flags=%s (0x%04x)",
1489 			    provider_flags_to_string(pp, flags, sizeof(flags)),
1490 			    pp->flags);
1491 		}
1492 		db_printf("\n");
1493 	}
1494 	if (!LIST_EMPTY(&pp->consumers)) {
1495 		LIST_FOREACH(cp, &pp->consumers, consumers) {
1496 			db_show_geom_consumer(indent + 2, cp);
1497 			if (db_pager_quit)
1498 				break;
1499 		}
1500 	}
1501 }
1502 
1503 static void
1504 db_show_geom_geom(int indent, struct g_geom *gp)
1505 {
1506 	struct g_provider *pp;
1507 	struct g_consumer *cp;
1508 	char flags[64];
1509 
1510 	if (indent == 0) {
1511 		gprintln("geom: %s (%p)", gp->name, gp);
1512 		gprintln("  class:     %s (%p)", gp->class->name, gp->class);
1513 		gprintln("  flags:     %s (0x%04x)",
1514 		    geom_flags_to_string(gp, flags, sizeof(flags)), gp->flags);
1515 		gprintln("  rank:      %d", gp->rank);
1516 		if (LIST_EMPTY(&gp->provider))
1517 			gprintln("  providers: none");
1518 		if (LIST_EMPTY(&gp->consumer))
1519 			gprintln("  consumers: none");
1520 	} else {
1521 		gprintf("geom: %s (%p), rank=%d", gp->name, gp, gp->rank);
1522 		if (gp->flags != 0) {
1523 			db_printf(", flags=%s (0x%04x)",
1524 			    geom_flags_to_string(gp, flags, sizeof(flags)),
1525 			    gp->flags);
1526 		}
1527 		db_printf("\n");
1528 	}
1529 	if (!LIST_EMPTY(&gp->provider)) {
1530 		LIST_FOREACH(pp, &gp->provider, provider) {
1531 			db_show_geom_provider(indent + 2, pp);
1532 			if (db_pager_quit)
1533 				break;
1534 		}
1535 	}
1536 	if (!LIST_EMPTY(&gp->consumer)) {
1537 		LIST_FOREACH(cp, &gp->consumer, consumer) {
1538 			db_show_geom_consumer(indent + 2, cp);
1539 			if (db_pager_quit)
1540 				break;
1541 		}
1542 	}
1543 }
1544 
1545 static void
1546 db_show_geom_class(struct g_class *mp)
1547 {
1548 	struct g_geom *gp;
1549 
1550 	db_printf("class: %s (%p)\n", mp->name, mp);
1551 	LIST_FOREACH(gp, &mp->geom, geom) {
1552 		db_show_geom_geom(2, gp);
1553 		if (db_pager_quit)
1554 			break;
1555 	}
1556 }
1557 
1558 /*
1559  * Print the GEOM topology or the given object.
1560  */
1561 DB_SHOW_COMMAND(geom, db_show_geom)
1562 {
1563 	struct g_class *mp;
1564 
1565 	if (!have_addr) {
1566 		/* No address given, print the entire topology. */
1567 		LIST_FOREACH(mp, &g_classes, class) {
1568 			db_show_geom_class(mp);
1569 			db_printf("\n");
1570 			if (db_pager_quit)
1571 				break;
1572 		}
1573 	} else {
1574 		switch (g_valid_obj((void *)addr)) {
1575 		case 1:
1576 			db_show_geom_class((struct g_class *)addr);
1577 			break;
1578 		case 2:
1579 			db_show_geom_geom(0, (struct g_geom *)addr);
1580 			break;
1581 		case 3:
1582 			db_show_geom_consumer(0, (struct g_consumer *)addr);
1583 			break;
1584 		case 4:
1585 			db_show_geom_provider(0, (struct g_provider *)addr);
1586 			break;
1587 		default:
1588 			db_printf("Not a GEOM object.\n");
1589 			break;
1590 		}
1591 	}
1592 }
1593 
1594 static void
1595 db_print_bio_cmd(struct bio *bp)
1596 {
1597 	db_printf("  cmd: ");
1598 	switch (bp->bio_cmd) {
1599 	case BIO_READ: db_printf("BIO_READ"); break;
1600 	case BIO_WRITE: db_printf("BIO_WRITE"); break;
1601 	case BIO_DELETE: db_printf("BIO_DELETE"); break;
1602 	case BIO_GETATTR: db_printf("BIO_GETATTR"); break;
1603 	case BIO_FLUSH: db_printf("BIO_FLUSH"); break;
1604 	case BIO_CMD0: db_printf("BIO_CMD0"); break;
1605 	case BIO_CMD1: db_printf("BIO_CMD1"); break;
1606 	case BIO_CMD2: db_printf("BIO_CMD2"); break;
1607 	case BIO_ZONE: db_printf("BIO_ZONE"); break;
1608 	default: db_printf("UNKNOWN"); break;
1609 	}
1610 	db_printf("\n");
1611 }
1612 
1613 static void
1614 db_print_bio_flags(struct bio *bp)
1615 {
1616 	int comma;
1617 
1618 	comma = 0;
1619 	db_printf("  flags: ");
1620 	if (bp->bio_flags & BIO_ERROR) {
1621 		db_printf("BIO_ERROR");
1622 		comma = 1;
1623 	}
1624 	if (bp->bio_flags & BIO_DONE) {
1625 		db_printf("%sBIO_DONE", (comma ? ", " : ""));
1626 		comma = 1;
1627 	}
1628 	if (bp->bio_flags & BIO_ONQUEUE)
1629 		db_printf("%sBIO_ONQUEUE", (comma ? ", " : ""));
1630 	db_printf("\n");
1631 }
1632 
1633 /*
1634  * Print useful information in a BIO
1635  */
1636 DB_SHOW_COMMAND(bio, db_show_bio)
1637 {
1638 	struct bio *bp;
1639 
1640 	if (have_addr) {
1641 		bp = (struct bio *)addr;
1642 		db_printf("BIO %p\n", bp);
1643 		db_print_bio_cmd(bp);
1644 		db_print_bio_flags(bp);
1645 		db_printf("  cflags: 0x%hx\n", bp->bio_cflags);
1646 		db_printf("  pflags: 0x%hx\n", bp->bio_pflags);
1647 		db_printf("  offset: %jd\n", (intmax_t)bp->bio_offset);
1648 		db_printf("  length: %jd\n", (intmax_t)bp->bio_length);
1649 		db_printf("  bcount: %ld\n", bp->bio_bcount);
1650 		db_printf("  resid: %ld\n", bp->bio_resid);
1651 		db_printf("  completed: %jd\n", (intmax_t)bp->bio_completed);
1652 		db_printf("  children: %u\n", bp->bio_children);
1653 		db_printf("  inbed: %u\n", bp->bio_inbed);
1654 		db_printf("  error: %d\n", bp->bio_error);
1655 		db_printf("  parent: %p\n", bp->bio_parent);
1656 		db_printf("  driver1: %p\n", bp->bio_driver1);
1657 		db_printf("  driver2: %p\n", bp->bio_driver2);
1658 		db_printf("  caller1: %p\n", bp->bio_caller1);
1659 		db_printf("  caller2: %p\n", bp->bio_caller2);
1660 		db_printf("  bio_from: %p\n", bp->bio_from);
1661 		db_printf("  bio_to: %p\n", bp->bio_to);
1662 
1663 #if defined(BUF_TRACKING) || defined(FULL_BUF_TRACKING)
1664 		db_printf("  bio_track_bp: %p\n", bp->bio_track_bp);
1665 #endif
1666 	}
1667 }
1668 
1669 #undef	gprintf
1670 #undef	gprintln
1671 #undef	ADDFLAG
1672 
1673 #endif	/* DDB */
1674