xref: /freebsd/sys/geom/geom_subr.c (revision 8bcb0991864975618c09697b1aca10683346d9f0)
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_INIT(&gp->aliases);
395 	LIST_INSERT_HEAD(&mp->geom, gp, geom);
396 	TAILQ_INSERT_HEAD(&geoms, gp, geoms);
397 	strcpy(gp->name, sbuf_data(sb));
398 	sbuf_delete(sb);
399 	/* Fill in defaults from class */
400 	gp->start = mp->start;
401 	gp->spoiled = mp->spoiled;
402 	gp->attrchanged = mp->attrchanged;
403 	gp->providergone = mp->providergone;
404 	gp->dumpconf = mp->dumpconf;
405 	gp->access = mp->access;
406 	gp->orphan = mp->orphan;
407 	gp->ioctl = mp->ioctl;
408 	gp->resize = mp->resize;
409 	return (gp);
410 }
411 
412 void
413 g_destroy_geom(struct g_geom *gp)
414 {
415 	struct g_geom_alias *gap, *gaptmp;
416 
417 	g_topology_assert();
418 	G_VALID_GEOM(gp);
419 	g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
420 	KASSERT(LIST_EMPTY(&gp->consumer),
421 	    ("g_destroy_geom(%s) with consumer(s) [%p]",
422 	    gp->name, LIST_FIRST(&gp->consumer)));
423 	KASSERT(LIST_EMPTY(&gp->provider),
424 	    ("g_destroy_geom(%s) with provider(s) [%p]",
425 	    gp->name, LIST_FIRST(&gp->provider)));
426 	g_cancel_event(gp);
427 	LIST_REMOVE(gp, geom);
428 	TAILQ_REMOVE(&geoms, gp, geoms);
429 	LIST_FOREACH_SAFE(gap, &gp->aliases, ga_next, gaptmp)
430 		g_free(gap);
431 	g_free(gp->name);
432 	g_free(gp);
433 }
434 
435 /*
436  * This function is called (repeatedly) until the geom has withered away.
437  */
438 void
439 g_wither_geom(struct g_geom *gp, int error)
440 {
441 	struct g_provider *pp;
442 
443 	g_topology_assert();
444 	G_VALID_GEOM(gp);
445 	g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name);
446 	if (!(gp->flags & G_GEOM_WITHER)) {
447 		gp->flags |= G_GEOM_WITHER;
448 		LIST_FOREACH(pp, &gp->provider, provider)
449 			if (!(pp->flags & G_PF_ORPHAN))
450 				g_orphan_provider(pp, error);
451 	}
452 	g_do_wither();
453 }
454 
455 /*
456  * Convenience function to destroy a particular provider.
457  */
458 void
459 g_wither_provider(struct g_provider *pp, int error)
460 {
461 
462 	pp->flags |= G_PF_WITHER;
463 	if (!(pp->flags & G_PF_ORPHAN))
464 		g_orphan_provider(pp, error);
465 }
466 
467 /*
468  * This function is called (repeatedly) until the has withered away.
469  */
470 void
471 g_wither_geom_close(struct g_geom *gp, int error)
472 {
473 	struct g_consumer *cp;
474 
475 	g_topology_assert();
476 	G_VALID_GEOM(gp);
477 	g_trace(G_T_TOPOLOGY, "g_wither_geom_close(%p(%s))", gp, gp->name);
478 	LIST_FOREACH(cp, &gp->consumer, consumer)
479 		if (cp->acr || cp->acw || cp->ace)
480 			g_access(cp, -cp->acr, -cp->acw, -cp->ace);
481 	g_wither_geom(gp, error);
482 }
483 
484 /*
485  * This function is called (repeatedly) until we cant wash away more
486  * withered bits at present.
487  */
488 void
489 g_wither_washer()
490 {
491 	struct g_class *mp;
492 	struct g_geom *gp, *gp2;
493 	struct g_provider *pp, *pp2;
494 	struct g_consumer *cp, *cp2;
495 
496 	g_topology_assert();
497 	LIST_FOREACH(mp, &g_classes, class) {
498 		LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
499 			LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
500 				if (!(pp->flags & G_PF_WITHER))
501 					continue;
502 				if (LIST_EMPTY(&pp->consumers))
503 					g_destroy_provider(pp);
504 			}
505 			if (!(gp->flags & G_GEOM_WITHER))
506 				continue;
507 			LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
508 				if (LIST_EMPTY(&pp->consumers))
509 					g_destroy_provider(pp);
510 			}
511 			LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp2) {
512 				if (cp->acr || cp->acw || cp->ace)
513 					continue;
514 				if (cp->provider != NULL)
515 					g_detach(cp);
516 				g_destroy_consumer(cp);
517 			}
518 			if (LIST_EMPTY(&gp->provider) &&
519 			    LIST_EMPTY(&gp->consumer))
520 				g_destroy_geom(gp);
521 		}
522 	}
523 }
524 
525 struct g_consumer *
526 g_new_consumer(struct g_geom *gp)
527 {
528 	struct g_consumer *cp;
529 
530 	g_topology_assert();
531 	G_VALID_GEOM(gp);
532 	KASSERT(!(gp->flags & G_GEOM_WITHER),
533 	    ("g_new_consumer on WITHERing geom(%s) (class %s)",
534 	    gp->name, gp->class->name));
535 	KASSERT(gp->orphan != NULL,
536 	    ("g_new_consumer on geom(%s) (class %s) without orphan",
537 	    gp->name, gp->class->name));
538 
539 	cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO);
540 	cp->geom = gp;
541 	cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED,
542 	    DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
543 	LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
544 	return(cp);
545 }
546 
547 void
548 g_destroy_consumer(struct g_consumer *cp)
549 {
550 	struct g_geom *gp;
551 
552 	g_topology_assert();
553 	G_VALID_CONSUMER(cp);
554 	g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
555 	KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
556 	KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
557 	KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
558 	KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
559 	g_cancel_event(cp);
560 	gp = cp->geom;
561 	LIST_REMOVE(cp, consumer);
562 	devstat_remove_entry(cp->stat);
563 	g_free(cp);
564 	if (gp->flags & G_GEOM_WITHER)
565 		g_do_wither();
566 }
567 
568 static void
569 g_new_provider_event(void *arg, int flag)
570 {
571 	struct g_class *mp;
572 	struct g_provider *pp;
573 	struct g_consumer *cp, *next_cp;
574 
575 	g_topology_assert();
576 	if (flag == EV_CANCEL)
577 		return;
578 	if (g_shutdown)
579 		return;
580 	pp = arg;
581 	G_VALID_PROVIDER(pp);
582 	KASSERT(!(pp->flags & G_PF_WITHER),
583 	    ("g_new_provider_event but withered"));
584 	LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, next_cp) {
585 		if ((cp->flags & G_CF_ORPHAN) == 0 &&
586 		    cp->geom->attrchanged != NULL)
587 			cp->geom->attrchanged(cp, "GEOM::media");
588 	}
589 	if (g_notaste)
590 		return;
591 	LIST_FOREACH(mp, &g_classes, class) {
592 		if (mp->taste == NULL)
593 			continue;
594 		LIST_FOREACH(cp, &pp->consumers, consumers)
595 			if (cp->geom->class == mp &&
596 			    (cp->flags & G_CF_ORPHAN) == 0)
597 				break;
598 		if (cp != NULL)
599 			continue;
600 		mp->taste(mp, pp, 0);
601 		g_topology_assert();
602 	}
603 }
604 
605 
606 struct g_provider *
607 g_new_providerf(struct g_geom *gp, const char *fmt, ...)
608 {
609 	struct g_provider *pp;
610 	struct sbuf *sb;
611 	va_list ap;
612 
613 	g_topology_assert();
614 	G_VALID_GEOM(gp);
615 	KASSERT(gp->access != NULL,
616 	    ("new provider on geom(%s) without ->access (class %s)",
617 	    gp->name, gp->class->name));
618 	KASSERT(gp->start != NULL,
619 	    ("new provider on geom(%s) without ->start (class %s)",
620 	    gp->name, gp->class->name));
621 	KASSERT(!(gp->flags & G_GEOM_WITHER),
622 	    ("new provider on WITHERing geom(%s) (class %s)",
623 	    gp->name, gp->class->name));
624 	sb = sbuf_new_auto();
625 	va_start(ap, fmt);
626 	sbuf_vprintf(sb, fmt, ap);
627 	va_end(ap);
628 	sbuf_finish(sb);
629 	pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
630 	pp->name = (char *)(pp + 1);
631 	strcpy(pp->name, sbuf_data(sb));
632 	sbuf_delete(sb);
633 	LIST_INIT(&pp->consumers);
634 	pp->error = ENXIO;
635 	pp->geom = gp;
636 	pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED,
637 	    DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
638 	LIST_INSERT_HEAD(&gp->provider, pp, provider);
639 	g_post_event(g_new_provider_event, pp, M_WAITOK, pp, gp, NULL);
640 	return (pp);
641 }
642 
643 void
644 g_error_provider(struct g_provider *pp, int error)
645 {
646 
647 	/* G_VALID_PROVIDER(pp);  We may not have g_topology */
648 	pp->error = error;
649 }
650 
651 static void
652 g_resize_provider_event(void *arg, int flag)
653 {
654 	struct g_hh00 *hh;
655 	struct g_class *mp;
656 	struct g_geom *gp;
657 	struct g_provider *pp;
658 	struct g_consumer *cp, *cp2;
659 	off_t size;
660 
661 	g_topology_assert();
662 	if (g_shutdown)
663 		return;
664 
665 	hh = arg;
666 	pp = hh->pp;
667 	size = hh->size;
668 	g_free(hh);
669 
670 	G_VALID_PROVIDER(pp);
671 	KASSERT(!(pp->flags & G_PF_WITHER),
672 	    ("g_resize_provider_event but withered"));
673 	g_trace(G_T_TOPOLOGY, "g_resize_provider_event(%p)", pp);
674 
675 	LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, cp2) {
676 		gp = cp->geom;
677 		if (gp->resize == NULL && size < pp->mediasize) {
678 			/*
679 			 * XXX: g_dev_orphan method does deferred destroying
680 			 * and it is possible, that other event could already
681 			 * call the orphan method. Check consumer's flags to
682 			 * do not schedule it twice.
683 			 */
684 			if (cp->flags & G_CF_ORPHAN)
685 				continue;
686 			cp->flags |= G_CF_ORPHAN;
687 			cp->geom->orphan(cp);
688 		}
689 	}
690 
691 	pp->mediasize = size;
692 
693 	LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, cp2) {
694 		gp = cp->geom;
695 		if ((gp->flags & G_GEOM_WITHER) == 0 && gp->resize != NULL)
696 			gp->resize(cp);
697 	}
698 
699 	/*
700 	 * After resizing, the previously invalid GEOM class metadata
701 	 * might become valid.  This means we should retaste.
702 	 */
703 	LIST_FOREACH(mp, &g_classes, class) {
704 		if (mp->taste == NULL)
705 			continue;
706 		LIST_FOREACH(cp, &pp->consumers, consumers)
707 			if (cp->geom->class == mp &&
708 			    (cp->flags & G_CF_ORPHAN) == 0)
709 				break;
710 		if (cp != NULL)
711 			continue;
712 		mp->taste(mp, pp, 0);
713 		g_topology_assert();
714 	}
715 }
716 
717 void
718 g_resize_provider(struct g_provider *pp, off_t size)
719 {
720 	struct g_hh00 *hh;
721 
722 	G_VALID_PROVIDER(pp);
723 	if (pp->flags & G_PF_WITHER)
724 		return;
725 
726 	if (size == pp->mediasize)
727 		return;
728 
729 	hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
730 	hh->pp = pp;
731 	hh->size = size;
732 	g_post_event(g_resize_provider_event, hh, M_WAITOK, NULL);
733 }
734 
735 #ifndef	_PATH_DEV
736 #define	_PATH_DEV	"/dev/"
737 #endif
738 
739 struct g_provider *
740 g_provider_by_name(char const *arg)
741 {
742 	struct g_class *cp;
743 	struct g_geom *gp;
744 	struct g_provider *pp, *wpp;
745 
746 	if (strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
747 		arg += sizeof(_PATH_DEV) - 1;
748 
749 	wpp = NULL;
750 	LIST_FOREACH(cp, &g_classes, class) {
751 		LIST_FOREACH(gp, &cp->geom, geom) {
752 			LIST_FOREACH(pp, &gp->provider, provider) {
753 				if (strcmp(arg, pp->name) != 0)
754 					continue;
755 				if ((gp->flags & G_GEOM_WITHER) == 0 &&
756 				    (pp->flags & G_PF_WITHER) == 0)
757 					return (pp);
758 				else
759 					wpp = pp;
760 			}
761 		}
762 	}
763 
764 	return (wpp);
765 }
766 
767 void
768 g_destroy_provider(struct g_provider *pp)
769 {
770 	struct g_geom *gp;
771 
772 	g_topology_assert();
773 	G_VALID_PROVIDER(pp);
774 	KASSERT(LIST_EMPTY(&pp->consumers),
775 	    ("g_destroy_provider but attached"));
776 	KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
777 	KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
778 	KASSERT (pp->ace == 0, ("g_destroy_provider with ace"));
779 	g_cancel_event(pp);
780 	LIST_REMOVE(pp, provider);
781 	gp = pp->geom;
782 	devstat_remove_entry(pp->stat);
783 	/*
784 	 * If a callback was provided, send notification that the provider
785 	 * is now gone.
786 	 */
787 	if (gp->providergone != NULL)
788 		gp->providergone(pp);
789 
790 	g_free(pp);
791 	if ((gp->flags & G_GEOM_WITHER))
792 		g_do_wither();
793 }
794 
795 /*
796  * We keep the "geoms" list sorted by topological order (== increasing
797  * numerical rank) at all times.
798  * When an attach is done, the attaching geoms rank is invalidated
799  * and it is moved to the tail of the list.
800  * All geoms later in the sequence has their ranks reevaluated in
801  * sequence.  If we cannot assign rank to a geom because it's
802  * prerequisites do not have rank, we move that element to the tail
803  * of the sequence with invalid rank as well.
804  * At some point we encounter our original geom and if we stil fail
805  * to assign it a rank, there must be a loop and we fail back to
806  * g_attach() which detach again and calls redo_rank again
807  * to fix up the damage.
808  * It would be much simpler code wise to do it recursively, but we
809  * can't risk that on the kernel stack.
810  */
811 
812 static int
813 redo_rank(struct g_geom *gp)
814 {
815 	struct g_consumer *cp;
816 	struct g_geom *gp1, *gp2;
817 	int n, m;
818 
819 	g_topology_assert();
820 	G_VALID_GEOM(gp);
821 
822 	/* Invalidate this geoms rank and move it to the tail */
823 	gp1 = TAILQ_NEXT(gp, geoms);
824 	if (gp1 != NULL) {
825 		gp->rank = 0;
826 		TAILQ_REMOVE(&geoms, gp, geoms);
827 		TAILQ_INSERT_TAIL(&geoms, gp, geoms);
828 	} else {
829 		gp1 = gp;
830 	}
831 
832 	/* re-rank the rest of the sequence */
833 	for (; gp1 != NULL; gp1 = gp2) {
834 		gp1->rank = 0;
835 		m = 1;
836 		LIST_FOREACH(cp, &gp1->consumer, consumer) {
837 			if (cp->provider == NULL)
838 				continue;
839 			n = cp->provider->geom->rank;
840 			if (n == 0) {
841 				m = 0;
842 				break;
843 			} else if (n >= m)
844 				m = n + 1;
845 		}
846 		gp1->rank = m;
847 		gp2 = TAILQ_NEXT(gp1, geoms);
848 
849 		/* got a rank, moving on */
850 		if (m != 0)
851 			continue;
852 
853 		/* no rank to original geom means loop */
854 		if (gp == gp1)
855 			return (ELOOP);
856 
857 		/* no rank, put it at the end move on */
858 		TAILQ_REMOVE(&geoms, gp1, geoms);
859 		TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
860 	}
861 	return (0);
862 }
863 
864 int
865 g_attach(struct g_consumer *cp, struct g_provider *pp)
866 {
867 	int error;
868 
869 	g_topology_assert();
870 	G_VALID_CONSUMER(cp);
871 	G_VALID_PROVIDER(pp);
872 	g_trace(G_T_TOPOLOGY, "g_attach(%p, %p)", cp, pp);
873 	KASSERT(cp->provider == NULL, ("attach but attached"));
874 	cp->provider = pp;
875 	cp->flags &= ~G_CF_ORPHAN;
876 	LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
877 	error = redo_rank(cp->geom);
878 	if (error) {
879 		LIST_REMOVE(cp, consumers);
880 		cp->provider = NULL;
881 		redo_rank(cp->geom);
882 	}
883 	return (error);
884 }
885 
886 void
887 g_detach(struct g_consumer *cp)
888 {
889 	struct g_provider *pp;
890 
891 	g_topology_assert();
892 	G_VALID_CONSUMER(cp);
893 	g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp);
894 	KASSERT(cp->provider != NULL, ("detach but not attached"));
895 	KASSERT(cp->acr == 0, ("detach but nonzero acr"));
896 	KASSERT(cp->acw == 0, ("detach but nonzero acw"));
897 	KASSERT(cp->ace == 0, ("detach but nonzero ace"));
898 	KASSERT(cp->nstart == cp->nend,
899 	    ("detach with active requests"));
900 	pp = cp->provider;
901 	LIST_REMOVE(cp, consumers);
902 	cp->provider = NULL;
903 	if ((cp->geom->flags & G_GEOM_WITHER) ||
904 	    (pp->geom->flags & G_GEOM_WITHER) ||
905 	    (pp->flags & G_PF_WITHER))
906 		g_do_wither();
907 	redo_rank(cp->geom);
908 }
909 
910 /*
911  * g_access()
912  *
913  * Access-check with delta values.  The question asked is "can provider
914  * "cp" change the access counters by the relative amounts dc[rwe] ?"
915  */
916 
917 int
918 g_access(struct g_consumer *cp, int dcr, int dcw, int dce)
919 {
920 	struct g_provider *pp;
921 	struct g_geom *gp;
922 	int pw, pe;
923 #ifdef INVARIANTS
924 	int sr, sw, se;
925 #endif
926 	int error;
927 
928 	g_topology_assert();
929 	G_VALID_CONSUMER(cp);
930 	pp = cp->provider;
931 	KASSERT(pp != NULL, ("access but not attached"));
932 	G_VALID_PROVIDER(pp);
933 	gp = pp->geom;
934 
935 	g_trace(G_T_ACCESS, "g_access(%p(%s), %d, %d, %d)",
936 	    cp, pp->name, dcr, dcw, dce);
937 
938 	KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
939 	KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
940 	KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
941 	KASSERT(dcr != 0 || dcw != 0 || dce != 0, ("NOP access request"));
942 	KASSERT(cp->acr + dcr != 0 || cp->acw + dcw != 0 ||
943 	    cp->ace + dce != 0 || cp->nstart == cp->nend,
944 	    ("Last close with active requests"));
945 	KASSERT(gp->access != NULL, ("NULL geom->access"));
946 
947 	/*
948 	 * If our class cares about being spoiled, and we have been, we
949 	 * are probably just ahead of the event telling us that.  Fail
950 	 * now rather than having to unravel this later.
951 	 */
952 	if (cp->geom->spoiled != NULL && (cp->flags & G_CF_SPOILED) &&
953 	    (dcr > 0 || dcw > 0 || dce > 0))
954 		return (ENXIO);
955 
956 	/*
957 	 * A number of GEOM classes either need to perform an I/O on the first
958 	 * open or to acquire a different subsystem's lock.  To do that they
959 	 * may have to drop the topology lock.
960 	 * Other GEOM classes perform special actions when opening a lower rank
961 	 * geom for the first time.  As a result, more than one thread may
962 	 * end up performing the special actions.
963 	 * So, we prevent concurrent "first" opens by marking the consumer with
964 	 * special flag.
965 	 *
966 	 * Note that if the geom's access method never drops the topology lock,
967 	 * then we will never see G_GEOM_IN_ACCESS here.
968 	 */
969 	while ((gp->flags & G_GEOM_IN_ACCESS) != 0) {
970 		g_trace(G_T_ACCESS,
971 		    "%s: race on geom %s via provider %s and consumer of %s",
972 		    __func__, gp->name, pp->name, cp->geom->name);
973 		gp->flags |= G_GEOM_ACCESS_WAIT;
974 		g_topology_sleep(gp, 0);
975 	}
976 
977 	/*
978 	 * Figure out what counts the provider would have had, if this
979 	 * consumer had (r0w0e0) at this time.
980 	 */
981 	pw = pp->acw - cp->acw;
982 	pe = pp->ace - cp->ace;
983 
984 	g_trace(G_T_ACCESS,
985     "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
986 	    dcr, dcw, dce,
987 	    cp->acr, cp->acw, cp->ace,
988 	    pp->acr, pp->acw, pp->ace,
989 	    pp, pp->name);
990 
991 	/* If foot-shooting is enabled, any open on rank#1 is OK */
992 	if ((g_debugflags & G_F_FOOTSHOOTING) && gp->rank == 1)
993 		;
994 	/* If we try exclusive but already write: fail */
995 	else if (dce > 0 && pw > 0)
996 		return (EPERM);
997 	/* If we try write but already exclusive: fail */
998 	else if (dcw > 0 && pe > 0)
999 		return (EPERM);
1000 	/* If we try to open more but provider is error'ed: fail */
1001 	else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0) {
1002 		printf("%s(%d): provider %s has error %d set\n",
1003 		    __func__, __LINE__, pp->name, pp->error);
1004 		return (pp->error);
1005 	}
1006 
1007 	/* Ok then... */
1008 
1009 #ifdef INVARIANTS
1010 	sr = cp->acr;
1011 	sw = cp->acw;
1012 	se = cp->ace;
1013 #endif
1014 	gp->flags |= G_GEOM_IN_ACCESS;
1015 	error = gp->access(pp, dcr, dcw, dce);
1016 	KASSERT(dcr > 0 || dcw > 0 || dce > 0 || error == 0,
1017 	    ("Geom provider %s::%s dcr=%d dcw=%d dce=%d error=%d failed "
1018 	    "closing ->access()", gp->class->name, pp->name, dcr, dcw,
1019 	    dce, error));
1020 
1021 	g_topology_assert();
1022 	gp->flags &= ~G_GEOM_IN_ACCESS;
1023 	KASSERT(cp->acr == sr && cp->acw == sw && cp->ace == se,
1024 	    ("Access counts changed during geom->access"));
1025 	if ((gp->flags & G_GEOM_ACCESS_WAIT) != 0) {
1026 		gp->flags &= ~G_GEOM_ACCESS_WAIT;
1027 		wakeup(gp);
1028 	}
1029 
1030 	if (!error) {
1031 		/*
1032 		 * If we open first write, spoil any partner consumers.
1033 		 * If we close last write and provider is not errored,
1034 		 * trigger re-taste.
1035 		 */
1036 		if (pp->acw == 0 && dcw != 0)
1037 			g_spoil(pp, cp);
1038 		else if (pp->acw != 0 && pp->acw == -dcw && pp->error == 0 &&
1039 		    !(gp->flags & G_GEOM_WITHER))
1040 			g_post_event(g_new_provider_event, pp, M_WAITOK,
1041 			    pp, NULL);
1042 
1043 		pp->acr += dcr;
1044 		pp->acw += dcw;
1045 		pp->ace += dce;
1046 		cp->acr += dcr;
1047 		cp->acw += dcw;
1048 		cp->ace += dce;
1049 		if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)
1050 			KASSERT(pp->sectorsize > 0,
1051 			    ("Provider %s lacks sectorsize", pp->name));
1052 		if ((cp->geom->flags & G_GEOM_WITHER) &&
1053 		    cp->acr == 0 && cp->acw == 0 && cp->ace == 0)
1054 			g_do_wither();
1055 	}
1056 	return (error);
1057 }
1058 
1059 int
1060 g_handleattr_int(struct bio *bp, const char *attribute, int val)
1061 {
1062 
1063 	return (g_handleattr(bp, attribute, &val, sizeof val));
1064 }
1065 
1066 int
1067 g_handleattr_uint16_t(struct bio *bp, const char *attribute, uint16_t val)
1068 {
1069 
1070 	return (g_handleattr(bp, attribute, &val, sizeof val));
1071 }
1072 
1073 int
1074 g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val)
1075 {
1076 
1077 	return (g_handleattr(bp, attribute, &val, sizeof val));
1078 }
1079 
1080 int
1081 g_handleattr_str(struct bio *bp, const char *attribute, const char *str)
1082 {
1083 
1084 	return (g_handleattr(bp, attribute, str, 0));
1085 }
1086 
1087 int
1088 g_handleattr(struct bio *bp, const char *attribute, const void *val, int len)
1089 {
1090 	int error = 0;
1091 
1092 	if (strcmp(bp->bio_attribute, attribute))
1093 		return (0);
1094 	if (len == 0) {
1095 		bzero(bp->bio_data, bp->bio_length);
1096 		if (strlcpy(bp->bio_data, val, bp->bio_length) >=
1097 		    bp->bio_length) {
1098 			printf("%s: %s %s bio_length %jd strlen %zu -> EFAULT\n",
1099 			    __func__, bp->bio_to->name, attribute,
1100 			    (intmax_t)bp->bio_length, strlen(val));
1101 			error = EFAULT;
1102 		}
1103 	} else if (bp->bio_length == len) {
1104 		bcopy(val, bp->bio_data, len);
1105 	} else {
1106 		printf("%s: %s %s bio_length %jd len %d -> EFAULT\n", __func__,
1107 		    bp->bio_to->name, attribute, (intmax_t)bp->bio_length, len);
1108 		error = EFAULT;
1109 	}
1110 	if (error == 0)
1111 		bp->bio_completed = bp->bio_length;
1112 	g_io_deliver(bp, error);
1113 	return (1);
1114 }
1115 
1116 int
1117 g_std_access(struct g_provider *pp,
1118 	int dr __unused, int dw __unused, int de __unused)
1119 {
1120 
1121 	g_topology_assert();
1122 	G_VALID_PROVIDER(pp);
1123         return (0);
1124 }
1125 
1126 void
1127 g_std_done(struct bio *bp)
1128 {
1129 	struct bio *bp2;
1130 
1131 	bp2 = bp->bio_parent;
1132 	if (bp2->bio_error == 0)
1133 		bp2->bio_error = bp->bio_error;
1134 	bp2->bio_completed += bp->bio_completed;
1135 	g_destroy_bio(bp);
1136 	bp2->bio_inbed++;
1137 	if (bp2->bio_children == bp2->bio_inbed)
1138 		g_io_deliver(bp2, bp2->bio_error);
1139 }
1140 
1141 /* XXX: maybe this is only g_slice_spoiled */
1142 
1143 void
1144 g_std_spoiled(struct g_consumer *cp)
1145 {
1146 	struct g_geom *gp;
1147 	struct g_provider *pp;
1148 
1149 	g_topology_assert();
1150 	G_VALID_CONSUMER(cp);
1151 	g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
1152 	cp->flags |= G_CF_ORPHAN;
1153 	g_detach(cp);
1154 	gp = cp->geom;
1155 	LIST_FOREACH(pp, &gp->provider, provider)
1156 		g_orphan_provider(pp, ENXIO);
1157 	g_destroy_consumer(cp);
1158 	if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
1159 		g_destroy_geom(gp);
1160 	else
1161 		gp->flags |= G_GEOM_WITHER;
1162 }
1163 
1164 /*
1165  * Spoiling happens when a provider is opened for writing, but consumers
1166  * which are configured by in-band data are attached (slicers for instance).
1167  * Since the write might potentially change the in-band data, such consumers
1168  * need to re-evaluate their existence after the writing session closes.
1169  * We do this by (offering to) tear them down when the open for write happens
1170  * in return for a re-taste when it closes again.
1171  * Together with the fact that such consumers grab an 'e' bit whenever they
1172  * are open, regardless of mode, this ends up DTRT.
1173  */
1174 
1175 static void
1176 g_spoil_event(void *arg, int flag)
1177 {
1178 	struct g_provider *pp;
1179 	struct g_consumer *cp, *cp2;
1180 
1181 	g_topology_assert();
1182 	if (flag == EV_CANCEL)
1183 		return;
1184 	pp = arg;
1185 	G_VALID_PROVIDER(pp);
1186 	g_trace(G_T_TOPOLOGY, "%s %p(%s:%s:%s)", __func__, pp,
1187 	    pp->geom->class->name, pp->geom->name, pp->name);
1188 	for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) {
1189 		cp2 = LIST_NEXT(cp, consumers);
1190 		if ((cp->flags & G_CF_SPOILED) == 0)
1191 			continue;
1192 		cp->flags &= ~G_CF_SPOILED;
1193 		if (cp->geom->spoiled == NULL)
1194 			continue;
1195 		cp->geom->spoiled(cp);
1196 		g_topology_assert();
1197 	}
1198 }
1199 
1200 void
1201 g_spoil(struct g_provider *pp, struct g_consumer *cp)
1202 {
1203 	struct g_consumer *cp2;
1204 
1205 	g_topology_assert();
1206 	G_VALID_PROVIDER(pp);
1207 	G_VALID_CONSUMER(cp);
1208 
1209 	LIST_FOREACH(cp2, &pp->consumers, consumers) {
1210 		if (cp2 == cp)
1211 			continue;
1212 /*
1213 		KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
1214 		KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
1215 */
1216 		KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
1217 		cp2->flags |= G_CF_SPOILED;
1218 	}
1219 	g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL);
1220 }
1221 
1222 static void
1223 g_media_changed_event(void *arg, int flag)
1224 {
1225 	struct g_provider *pp;
1226 	int retaste;
1227 
1228 	g_topology_assert();
1229 	if (flag == EV_CANCEL)
1230 		return;
1231 	pp = arg;
1232 	G_VALID_PROVIDER(pp);
1233 
1234 	/*
1235 	 * If provider was not open for writing, queue retaste after spoiling.
1236 	 * If it was, retaste will happen automatically on close.
1237 	 */
1238 	retaste = (pp->acw == 0 && pp->error == 0 &&
1239 	    !(pp->geom->flags & G_GEOM_WITHER));
1240 	g_spoil_event(arg, flag);
1241 	if (retaste)
1242 		g_post_event(g_new_provider_event, pp, M_WAITOK, pp, NULL);
1243 }
1244 
1245 int
1246 g_media_changed(struct g_provider *pp, int flag)
1247 {
1248 	struct g_consumer *cp;
1249 
1250 	LIST_FOREACH(cp, &pp->consumers, consumers)
1251 		cp->flags |= G_CF_SPOILED;
1252 	return (g_post_event(g_media_changed_event, pp, flag, pp, NULL));
1253 }
1254 
1255 int
1256 g_media_gone(struct g_provider *pp, int flag)
1257 {
1258 	struct g_consumer *cp;
1259 
1260 	LIST_FOREACH(cp, &pp->consumers, consumers)
1261 		cp->flags |= G_CF_SPOILED;
1262 	return (g_post_event(g_spoil_event, pp, flag, pp, NULL));
1263 }
1264 
1265 int
1266 g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len)
1267 {
1268 	int error, i;
1269 
1270 	i = len;
1271 	error = g_io_getattr(attr, cp, &i, var);
1272 	if (error)
1273 		return (error);
1274 	if (i != len)
1275 		return (EINVAL);
1276 	return (0);
1277 }
1278 
1279 static int
1280 g_get_device_prefix_len(const char *name)
1281 {
1282 	int len;
1283 
1284 	if (strncmp(name, "ada", 3) == 0)
1285 		len = 3;
1286 	else if (strncmp(name, "ad", 2) == 0)
1287 		len = 2;
1288 	else
1289 		return (0);
1290 	if (name[len] < '0' || name[len] > '9')
1291 		return (0);
1292 	do {
1293 		len++;
1294 	} while (name[len] >= '0' && name[len] <= '9');
1295 	return (len);
1296 }
1297 
1298 int
1299 g_compare_names(const char *namea, const char *nameb)
1300 {
1301 	int deva, devb;
1302 
1303 	if (strcmp(namea, nameb) == 0)
1304 		return (1);
1305 	deva = g_get_device_prefix_len(namea);
1306 	if (deva == 0)
1307 		return (0);
1308 	devb = g_get_device_prefix_len(nameb);
1309 	if (devb == 0)
1310 		return (0);
1311 	if (strcmp(namea + deva, nameb + devb) == 0)
1312 		return (1);
1313 	return (0);
1314 }
1315 
1316 void
1317 g_geom_add_alias(struct g_geom *gp, const char *alias)
1318 {
1319 	struct g_geom_alias *gap;
1320 
1321 	gap = (struct g_geom_alias *)g_malloc(
1322 		sizeof(struct g_geom_alias) + strlen(alias) + 1, M_WAITOK);
1323 	strcpy((char *)(gap + 1), alias);
1324 	gap->ga_alias = (const char *)(gap + 1);
1325 	LIST_INSERT_HEAD(&gp->aliases, gap, ga_next);
1326 }
1327 
1328 #if defined(DIAGNOSTIC) || defined(DDB)
1329 /*
1330  * This function walks the mesh and returns a non-zero integer if it
1331  * finds the argument pointer is an object. The return value indicates
1332  * which type of object it is believed to be. If topology is not locked,
1333  * this function is potentially dangerous, but we don't assert that the
1334  * topology lock is held when called from debugger.
1335  */
1336 int
1337 g_valid_obj(void const *ptr)
1338 {
1339 	struct g_class *mp;
1340 	struct g_geom *gp;
1341 	struct g_consumer *cp;
1342 	struct g_provider *pp;
1343 
1344 #ifdef KDB
1345 	if (kdb_active == 0)
1346 #endif
1347 		g_topology_assert();
1348 
1349 	LIST_FOREACH(mp, &g_classes, class) {
1350 		if (ptr == mp)
1351 			return (1);
1352 		LIST_FOREACH(gp, &mp->geom, geom) {
1353 			if (ptr == gp)
1354 				return (2);
1355 			LIST_FOREACH(cp, &gp->consumer, consumer)
1356 				if (ptr == cp)
1357 					return (3);
1358 			LIST_FOREACH(pp, &gp->provider, provider)
1359 				if (ptr == pp)
1360 					return (4);
1361 		}
1362 	}
1363 	return(0);
1364 }
1365 #endif
1366 
1367 #ifdef DDB
1368 
1369 #define	gprintf(...)	do {						\
1370 	db_printf("%*s", indent, "");					\
1371 	db_printf(__VA_ARGS__);						\
1372 } while (0)
1373 #define	gprintln(...)	do {						\
1374 	gprintf(__VA_ARGS__);						\
1375 	db_printf("\n");						\
1376 } while (0)
1377 
1378 #define	ADDFLAG(obj, flag, sflag)	do {				\
1379 	if ((obj)->flags & (flag)) {					\
1380 		if (comma)						\
1381 			strlcat(str, ",", size);			\
1382 		strlcat(str, (sflag), size);				\
1383 		comma = 1;						\
1384 	}								\
1385 } while (0)
1386 
1387 static char *
1388 provider_flags_to_string(struct g_provider *pp, char *str, size_t size)
1389 {
1390 	int comma = 0;
1391 
1392 	bzero(str, size);
1393 	if (pp->flags == 0) {
1394 		strlcpy(str, "NONE", size);
1395 		return (str);
1396 	}
1397 	ADDFLAG(pp, G_PF_WITHER, "G_PF_WITHER");
1398 	ADDFLAG(pp, G_PF_ORPHAN, "G_PF_ORPHAN");
1399 	return (str);
1400 }
1401 
1402 static char *
1403 geom_flags_to_string(struct g_geom *gp, char *str, size_t size)
1404 {
1405 	int comma = 0;
1406 
1407 	bzero(str, size);
1408 	if (gp->flags == 0) {
1409 		strlcpy(str, "NONE", size);
1410 		return (str);
1411 	}
1412 	ADDFLAG(gp, G_GEOM_WITHER, "G_GEOM_WITHER");
1413 	return (str);
1414 }
1415 static void
1416 db_show_geom_consumer(int indent, struct g_consumer *cp)
1417 {
1418 
1419 	if (indent == 0) {
1420 		gprintln("consumer: %p", cp);
1421 		gprintln("  class:    %s (%p)", cp->geom->class->name,
1422 		    cp->geom->class);
1423 		gprintln("  geom:     %s (%p)", cp->geom->name, cp->geom);
1424 		if (cp->provider == NULL)
1425 			gprintln("  provider: none");
1426 		else {
1427 			gprintln("  provider: %s (%p)", cp->provider->name,
1428 			    cp->provider);
1429 		}
1430 		gprintln("  access:   r%dw%de%d", cp->acr, cp->acw, cp->ace);
1431 		gprintln("  flags:    0x%04x", cp->flags);
1432 #ifdef INVARIANTS
1433 		gprintln("  nstart:   %u", cp->nstart);
1434 		gprintln("  nend:     %u", cp->nend);
1435 #endif
1436 	} else {
1437 		gprintf("consumer: %p (%s), access=r%dw%de%d", cp,
1438 		    cp->provider != NULL ? cp->provider->name : "none",
1439 		    cp->acr, cp->acw, cp->ace);
1440 		if (cp->flags)
1441 			db_printf(", flags=0x%04x", cp->flags);
1442 		db_printf("\n");
1443 	}
1444 }
1445 
1446 static void
1447 db_show_geom_provider(int indent, struct g_provider *pp)
1448 {
1449 	struct g_consumer *cp;
1450 	char flags[64];
1451 
1452 	if (indent == 0) {
1453 		gprintln("provider: %s (%p)", pp->name, pp);
1454 		gprintln("  class:        %s (%p)", pp->geom->class->name,
1455 		    pp->geom->class);
1456 		gprintln("  geom:         %s (%p)", pp->geom->name, pp->geom);
1457 		gprintln("  mediasize:    %jd", (intmax_t)pp->mediasize);
1458 		gprintln("  sectorsize:   %u", pp->sectorsize);
1459 		gprintln("  stripesize:   %ju", (uintmax_t)pp->stripesize);
1460 		gprintln("  stripeoffset: %ju", (uintmax_t)pp->stripeoffset);
1461 		gprintln("  access:       r%dw%de%d", pp->acr, pp->acw,
1462 		    pp->ace);
1463 		gprintln("  flags:        %s (0x%04x)",
1464 		    provider_flags_to_string(pp, flags, sizeof(flags)),
1465 		    pp->flags);
1466 		gprintln("  error:        %d", pp->error);
1467 		if (LIST_EMPTY(&pp->consumers))
1468 			gprintln("  consumers:    none");
1469 	} else {
1470 		gprintf("provider: %s (%p), access=r%dw%de%d",
1471 		    pp->name, pp, pp->acr, pp->acw, pp->ace);
1472 		if (pp->flags != 0) {
1473 			db_printf(", flags=%s (0x%04x)",
1474 			    provider_flags_to_string(pp, flags, sizeof(flags)),
1475 			    pp->flags);
1476 		}
1477 		db_printf("\n");
1478 	}
1479 	if (!LIST_EMPTY(&pp->consumers)) {
1480 		LIST_FOREACH(cp, &pp->consumers, consumers) {
1481 			db_show_geom_consumer(indent + 2, cp);
1482 			if (db_pager_quit)
1483 				break;
1484 		}
1485 	}
1486 }
1487 
1488 static void
1489 db_show_geom_geom(int indent, struct g_geom *gp)
1490 {
1491 	struct g_provider *pp;
1492 	struct g_consumer *cp;
1493 	char flags[64];
1494 
1495 	if (indent == 0) {
1496 		gprintln("geom: %s (%p)", gp->name, gp);
1497 		gprintln("  class:     %s (%p)", gp->class->name, gp->class);
1498 		gprintln("  flags:     %s (0x%04x)",
1499 		    geom_flags_to_string(gp, flags, sizeof(flags)), gp->flags);
1500 		gprintln("  rank:      %d", gp->rank);
1501 		if (LIST_EMPTY(&gp->provider))
1502 			gprintln("  providers: none");
1503 		if (LIST_EMPTY(&gp->consumer))
1504 			gprintln("  consumers: none");
1505 	} else {
1506 		gprintf("geom: %s (%p), rank=%d", gp->name, gp, gp->rank);
1507 		if (gp->flags != 0) {
1508 			db_printf(", flags=%s (0x%04x)",
1509 			    geom_flags_to_string(gp, flags, sizeof(flags)),
1510 			    gp->flags);
1511 		}
1512 		db_printf("\n");
1513 	}
1514 	if (!LIST_EMPTY(&gp->provider)) {
1515 		LIST_FOREACH(pp, &gp->provider, provider) {
1516 			db_show_geom_provider(indent + 2, pp);
1517 			if (db_pager_quit)
1518 				break;
1519 		}
1520 	}
1521 	if (!LIST_EMPTY(&gp->consumer)) {
1522 		LIST_FOREACH(cp, &gp->consumer, consumer) {
1523 			db_show_geom_consumer(indent + 2, cp);
1524 			if (db_pager_quit)
1525 				break;
1526 		}
1527 	}
1528 }
1529 
1530 static void
1531 db_show_geom_class(struct g_class *mp)
1532 {
1533 	struct g_geom *gp;
1534 
1535 	db_printf("class: %s (%p)\n", mp->name, mp);
1536 	LIST_FOREACH(gp, &mp->geom, geom) {
1537 		db_show_geom_geom(2, gp);
1538 		if (db_pager_quit)
1539 			break;
1540 	}
1541 }
1542 
1543 /*
1544  * Print the GEOM topology or the given object.
1545  */
1546 DB_SHOW_COMMAND(geom, db_show_geom)
1547 {
1548 	struct g_class *mp;
1549 
1550 	if (!have_addr) {
1551 		/* No address given, print the entire topology. */
1552 		LIST_FOREACH(mp, &g_classes, class) {
1553 			db_show_geom_class(mp);
1554 			db_printf("\n");
1555 			if (db_pager_quit)
1556 				break;
1557 		}
1558 	} else {
1559 		switch (g_valid_obj((void *)addr)) {
1560 		case 1:
1561 			db_show_geom_class((struct g_class *)addr);
1562 			break;
1563 		case 2:
1564 			db_show_geom_geom(0, (struct g_geom *)addr);
1565 			break;
1566 		case 3:
1567 			db_show_geom_consumer(0, (struct g_consumer *)addr);
1568 			break;
1569 		case 4:
1570 			db_show_geom_provider(0, (struct g_provider *)addr);
1571 			break;
1572 		default:
1573 			db_printf("Not a GEOM object.\n");
1574 			break;
1575 		}
1576 	}
1577 }
1578 
1579 static void
1580 db_print_bio_cmd(struct bio *bp)
1581 {
1582 	db_printf("  cmd: ");
1583 	switch (bp->bio_cmd) {
1584 	case BIO_READ: db_printf("BIO_READ"); break;
1585 	case BIO_WRITE: db_printf("BIO_WRITE"); break;
1586 	case BIO_DELETE: db_printf("BIO_DELETE"); break;
1587 	case BIO_GETATTR: db_printf("BIO_GETATTR"); break;
1588 	case BIO_FLUSH: db_printf("BIO_FLUSH"); break;
1589 	case BIO_CMD0: db_printf("BIO_CMD0"); break;
1590 	case BIO_CMD1: db_printf("BIO_CMD1"); break;
1591 	case BIO_CMD2: db_printf("BIO_CMD2"); break;
1592 	case BIO_ZONE: db_printf("BIO_ZONE"); break;
1593 	default: db_printf("UNKNOWN"); break;
1594 	}
1595 	db_printf("\n");
1596 }
1597 
1598 static void
1599 db_print_bio_flags(struct bio *bp)
1600 {
1601 	int comma;
1602 
1603 	comma = 0;
1604 	db_printf("  flags: ");
1605 	if (bp->bio_flags & BIO_ERROR) {
1606 		db_printf("BIO_ERROR");
1607 		comma = 1;
1608 	}
1609 	if (bp->bio_flags & BIO_DONE) {
1610 		db_printf("%sBIO_DONE", (comma ? ", " : ""));
1611 		comma = 1;
1612 	}
1613 	if (bp->bio_flags & BIO_ONQUEUE)
1614 		db_printf("%sBIO_ONQUEUE", (comma ? ", " : ""));
1615 	db_printf("\n");
1616 }
1617 
1618 /*
1619  * Print useful information in a BIO
1620  */
1621 DB_SHOW_COMMAND(bio, db_show_bio)
1622 {
1623 	struct bio *bp;
1624 
1625 	if (have_addr) {
1626 		bp = (struct bio *)addr;
1627 		db_printf("BIO %p\n", bp);
1628 		db_print_bio_cmd(bp);
1629 		db_print_bio_flags(bp);
1630 		db_printf("  cflags: 0x%hx\n", bp->bio_cflags);
1631 		db_printf("  pflags: 0x%hx\n", bp->bio_pflags);
1632 		db_printf("  offset: %jd\n", (intmax_t)bp->bio_offset);
1633 		db_printf("  length: %jd\n", (intmax_t)bp->bio_length);
1634 		db_printf("  bcount: %ld\n", bp->bio_bcount);
1635 		db_printf("  resid: %ld\n", bp->bio_resid);
1636 		db_printf("  completed: %jd\n", (intmax_t)bp->bio_completed);
1637 		db_printf("  children: %u\n", bp->bio_children);
1638 		db_printf("  inbed: %u\n", bp->bio_inbed);
1639 		db_printf("  error: %d\n", bp->bio_error);
1640 		db_printf("  parent: %p\n", bp->bio_parent);
1641 		db_printf("  driver1: %p\n", bp->bio_driver1);
1642 		db_printf("  driver2: %p\n", bp->bio_driver2);
1643 		db_printf("  caller1: %p\n", bp->bio_caller1);
1644 		db_printf("  caller2: %p\n", bp->bio_caller2);
1645 		db_printf("  bio_from: %p\n", bp->bio_from);
1646 		db_printf("  bio_to: %p\n", bp->bio_to);
1647 
1648 #if defined(BUF_TRACKING) || defined(FULL_BUF_TRACKING)
1649 		db_printf("  bio_track_bp: %p\n", bp->bio_track_bp);
1650 #endif
1651 	}
1652 }
1653 
1654 #undef	gprintf
1655 #undef	gprintln
1656 #undef	ADDFLAG
1657 
1658 #endif	/* DDB */
1659