xref: /freebsd/sys/geom/geom_subr.c (revision 7aa65846327fe5bc7e5961c2f7fd0c61f2ec0b01)
1 /*-
2  * Copyright (c) 2002 Poul-Henning Kamp
3  * Copyright (c) 2002 Networks Associates Technology, Inc.
4  * All rights reserved.
5  *
6  * This software was developed for the FreeBSD Project by Poul-Henning Kamp
7  * and NAI Labs, the Security Research Division of Network Associates, Inc.
8  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
9  * DARPA CHATS research program.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. The names of the authors may not be used to endorse or promote
20  *    products derived from this software without specific prior written
21  *    permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
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 <geom/geom.h>
55 #include <geom/geom_int.h>
56 #include <machine/stdarg.h>
57 
58 #ifdef DDB
59 #include <ddb/ddb.h>
60 #endif
61 
62 #ifdef KDB
63 #include <sys/kdb.h>
64 #endif
65 
66 struct class_list_head g_classes = LIST_HEAD_INITIALIZER(g_classes);
67 static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms);
68 char *g_wait_event, *g_wait_up, *g_wait_down, *g_wait_sim;
69 
70 struct g_hh00 {
71 	struct g_class	*mp;
72 	int		error;
73 	int		post;
74 };
75 
76 /*
77  * This event offers a new class a chance to taste all preexisting providers.
78  */
79 static void
80 g_load_class(void *arg, int flag)
81 {
82 	struct g_hh00 *hh;
83 	struct g_class *mp2, *mp;
84 	struct g_geom *gp;
85 	struct g_provider *pp;
86 
87 	g_topology_assert();
88 	if (flag == EV_CANCEL)	/* XXX: can't happen ? */
89 		return;
90 	if (g_shutdown)
91 		return;
92 
93 	hh = arg;
94 	mp = hh->mp;
95 	hh->error = 0;
96 	if (hh->post) {
97 		g_free(hh);
98 		hh = NULL;
99 	}
100 	g_trace(G_T_TOPOLOGY, "g_load_class(%s)", mp->name);
101 	KASSERT(mp->name != NULL && *mp->name != '\0',
102 	    ("GEOM class has no name"));
103 	LIST_FOREACH(mp2, &g_classes, class) {
104 		if (mp2 == mp) {
105 			printf("The GEOM class %s is already loaded.\n",
106 			    mp2->name);
107 			if (hh != NULL)
108 				hh->error = EEXIST;
109 			return;
110 		} else if (strcmp(mp2->name, mp->name) == 0) {
111 			printf("A GEOM class %s is already loaded.\n",
112 			    mp2->name);
113 			if (hh != NULL)
114 				hh->error = EEXIST;
115 			return;
116 		}
117 	}
118 
119 	LIST_INIT(&mp->geom);
120 	LIST_INSERT_HEAD(&g_classes, mp, class);
121 	if (mp->init != NULL)
122 		mp->init(mp);
123 	if (mp->taste == NULL)
124 		return;
125 	LIST_FOREACH(mp2, &g_classes, class) {
126 		if (mp == mp2)
127 			continue;
128 		LIST_FOREACH(gp, &mp2->geom, geom) {
129 			LIST_FOREACH(pp, &gp->provider, provider) {
130 				mp->taste(mp, pp, 0);
131 				g_topology_assert();
132 			}
133 		}
134 	}
135 }
136 
137 static int
138 g_unload_class(struct g_class *mp)
139 {
140 	struct g_geom *gp;
141 	struct g_provider *pp;
142 	struct g_consumer *cp;
143 	int error;
144 
145 	g_topology_lock();
146 	g_trace(G_T_TOPOLOGY, "g_unload_class(%s)", mp->name);
147 retry:
148 	G_VALID_CLASS(mp);
149 	LIST_FOREACH(gp, &mp->geom, geom) {
150 		/* We refuse to unload if anything is open */
151 		LIST_FOREACH(pp, &gp->provider, provider)
152 			if (pp->acr || pp->acw || pp->ace) {
153 				g_topology_unlock();
154 				return (EBUSY);
155 			}
156 		LIST_FOREACH(cp, &gp->consumer, consumer)
157 			if (cp->acr || cp->acw || cp->ace) {
158 				g_topology_unlock();
159 				return (EBUSY);
160 			}
161 		/* If the geom is withering, wait for it to finish. */
162 		if (gp->flags & G_GEOM_WITHER) {
163 			g_topology_sleep(mp, 1);
164 			goto retry;
165 		}
166 	}
167 
168 	/*
169 	 * We allow unloading if we have no geoms, or a class
170 	 * method we can use to get rid of them.
171 	 */
172 	if (!LIST_EMPTY(&mp->geom) && mp->destroy_geom == NULL) {
173 		g_topology_unlock();
174 		return (EOPNOTSUPP);
175 	}
176 
177 	/* Bar new entries */
178 	mp->taste = NULL;
179 	mp->config = NULL;
180 
181 	LIST_FOREACH(gp, &mp->geom, geom) {
182 		error = mp->destroy_geom(NULL, mp, gp);
183 		if (error != 0) {
184 			g_topology_unlock();
185 			return (error);
186 		}
187 	}
188 	/* Wait for withering to finish. */
189 	for (;;) {
190 		gp = LIST_FIRST(&mp->geom);
191 		if (gp == NULL)
192 			break;
193 		KASSERT(gp->flags & G_GEOM_WITHER,
194 		   ("Non-withering geom in class %s", mp->name));
195 		g_topology_sleep(mp, 1);
196 	}
197 	G_VALID_CLASS(mp);
198 	if (mp->fini != NULL)
199 		mp->fini(mp);
200 	LIST_REMOVE(mp, class);
201 	g_topology_unlock();
202 
203 	return (0);
204 }
205 
206 int
207 g_modevent(module_t mod, int type, void *data)
208 {
209 	struct g_hh00 *hh;
210 	int error;
211 	static int g_ignition;
212 	struct g_class *mp;
213 
214 	mp = data;
215 	if (mp->version != G_VERSION) {
216 		printf("GEOM class %s has Wrong version %x\n",
217 		    mp->name, mp->version);
218 		return (EINVAL);
219 	}
220 	if (!g_ignition) {
221 		g_ignition++;
222 		g_init();
223 	}
224 	error = EOPNOTSUPP;
225 	switch (type) {
226 	case MOD_LOAD:
227 		g_trace(G_T_TOPOLOGY, "g_modevent(%s, LOAD)", mp->name);
228 		hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
229 		hh->mp = mp;
230 		/*
231 		 * Once the system is not cold, MOD_LOAD calls will be
232 		 * from the userland and the g_event thread will be able
233 		 * to acknowledge their completion.
234 		 */
235 		if (cold) {
236 			hh->post = 1;
237 			error = g_post_event(g_load_class, hh, M_WAITOK, NULL);
238 		} else {
239 			error = g_waitfor_event(g_load_class, hh, M_WAITOK,
240 			    NULL);
241 			if (error == 0)
242 				error = hh->error;
243 			g_free(hh);
244 		}
245 		break;
246 	case MOD_UNLOAD:
247 		g_trace(G_T_TOPOLOGY, "g_modevent(%s, UNLOAD)", mp->name);
248 		DROP_GIANT();
249 		error = g_unload_class(mp);
250 		PICKUP_GIANT();
251 		if (error == 0) {
252 			KASSERT(LIST_EMPTY(&mp->geom),
253 			    ("Unloaded class (%s) still has geom", mp->name));
254 		}
255 		break;
256 	}
257 	return (error);
258 }
259 
260 static void
261 g_retaste_event(void *arg, int flag)
262 {
263 	struct g_class *cp, *mp;
264 	struct g_geom *gp, *gp2;
265 	struct g_hh00 *hh;
266 	struct g_provider *pp;
267 
268 	g_topology_assert();
269 	if (flag == EV_CANCEL)  /* XXX: can't happen ? */
270 		return;
271 	if (g_shutdown)
272 		return;
273 
274 	hh = arg;
275 	mp = hh->mp;
276 	hh->error = 0;
277 	if (hh->post) {
278 		g_free(hh);
279 		hh = NULL;
280 	}
281 	g_trace(G_T_TOPOLOGY, "g_retaste(%s)", mp->name);
282 
283 	LIST_FOREACH(cp, &g_classes, class) {
284 		LIST_FOREACH(gp, &cp->geom, geom) {
285 			LIST_FOREACH(pp, &gp->provider, provider) {
286 				if (pp->acr || pp->acw || pp->ace)
287 					continue;
288 				LIST_FOREACH(gp2, &mp->geom, geom) {
289 					if (!strcmp(pp->name, gp2->name))
290 						break;
291 				}
292 				if (gp2 != NULL)
293 					g_wither_geom(gp2, ENXIO);
294 				mp->taste(mp, pp, 0);
295 				g_topology_assert();
296 			}
297 		}
298 	}
299 }
300 
301 int
302 g_retaste(struct g_class *mp)
303 {
304 	struct g_hh00 *hh;
305 	int error;
306 
307 	if (mp->taste == NULL)
308 		return (EINVAL);
309 
310 	hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
311 	hh->mp = mp;
312 
313 	if (cold) {
314 		hh->post = 1;
315 		error = g_post_event(g_retaste_event, hh, M_WAITOK, NULL);
316 	} else {
317 		error = g_waitfor_event(g_retaste_event, hh, M_WAITOK, NULL);
318 		if (error == 0)
319 			error = hh->error;
320 		g_free(hh);
321 	}
322 
323 	return (error);
324 }
325 
326 struct g_geom *
327 g_new_geomf(struct g_class *mp, const char *fmt, ...)
328 {
329 	struct g_geom *gp;
330 	va_list ap;
331 	struct sbuf *sb;
332 
333 	g_topology_assert();
334 	G_VALID_CLASS(mp);
335 	sb = sbuf_new_auto();
336 	va_start(ap, fmt);
337 	sbuf_vprintf(sb, fmt, ap);
338 	va_end(ap);
339 	sbuf_finish(sb);
340 	gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO);
341 	gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
342 	gp->class = mp;
343 	gp->rank = 1;
344 	LIST_INIT(&gp->consumer);
345 	LIST_INIT(&gp->provider);
346 	LIST_INSERT_HEAD(&mp->geom, gp, geom);
347 	TAILQ_INSERT_HEAD(&geoms, gp, geoms);
348 	strcpy(gp->name, sbuf_data(sb));
349 	sbuf_delete(sb);
350 	/* Fill in defaults from class */
351 	gp->start = mp->start;
352 	gp->spoiled = mp->spoiled;
353 	gp->attrchanged = mp->attrchanged;
354 	gp->dumpconf = mp->dumpconf;
355 	gp->access = mp->access;
356 	gp->orphan = mp->orphan;
357 	gp->ioctl = mp->ioctl;
358 	return (gp);
359 }
360 
361 void
362 g_destroy_geom(struct g_geom *gp)
363 {
364 
365 	g_topology_assert();
366 	G_VALID_GEOM(gp);
367 	g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
368 	KASSERT(LIST_EMPTY(&gp->consumer),
369 	    ("g_destroy_geom(%s) with consumer(s) [%p]",
370 	    gp->name, LIST_FIRST(&gp->consumer)));
371 	KASSERT(LIST_EMPTY(&gp->provider),
372 	    ("g_destroy_geom(%s) with provider(s) [%p]",
373 	    gp->name, LIST_FIRST(&gp->provider)));
374 	g_cancel_event(gp);
375 	LIST_REMOVE(gp, geom);
376 	TAILQ_REMOVE(&geoms, gp, geoms);
377 	g_free(gp->name);
378 	g_free(gp);
379 }
380 
381 /*
382  * This function is called (repeatedly) until the geom has withered away.
383  */
384 void
385 g_wither_geom(struct g_geom *gp, int error)
386 {
387 	struct g_provider *pp;
388 
389 	g_topology_assert();
390 	G_VALID_GEOM(gp);
391 	g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name);
392 	if (!(gp->flags & G_GEOM_WITHER)) {
393 		gp->flags |= G_GEOM_WITHER;
394 		LIST_FOREACH(pp, &gp->provider, provider)
395 			if (!(pp->flags & G_PF_ORPHAN))
396 				g_orphan_provider(pp, error);
397 	}
398 	g_do_wither();
399 }
400 
401 /*
402  * Convenience function to destroy a particular provider.
403  */
404 void
405 g_wither_provider(struct g_provider *pp, int error)
406 {
407 
408 	pp->flags |= G_PF_WITHER;
409 	if (!(pp->flags & G_PF_ORPHAN))
410 		g_orphan_provider(pp, error);
411 }
412 
413 /*
414  * This function is called (repeatedly) until the has withered away.
415  */
416 void
417 g_wither_geom_close(struct g_geom *gp, int error)
418 {
419 	struct g_consumer *cp;
420 
421 	g_topology_assert();
422 	G_VALID_GEOM(gp);
423 	g_trace(G_T_TOPOLOGY, "g_wither_geom_close(%p(%s))", gp, gp->name);
424 	LIST_FOREACH(cp, &gp->consumer, consumer)
425 		if (cp->acr || cp->acw || cp->ace)
426 			g_access(cp, -cp->acr, -cp->acw, -cp->ace);
427 	g_wither_geom(gp, error);
428 }
429 
430 /*
431  * This function is called (repeatedly) until we cant wash away more
432  * withered bits at present.  Return value contains two bits.  Bit 0
433  * set means "withering stuff we can't wash now", bit 1 means "call
434  * me again, there may be stuff I didn't get the first time around.
435  */
436 int
437 g_wither_washer()
438 {
439 	struct g_class *mp;
440 	struct g_geom *gp, *gp2;
441 	struct g_provider *pp, *pp2;
442 	struct g_consumer *cp, *cp2;
443 	int result;
444 
445 	result = 0;
446 	g_topology_assert();
447 	LIST_FOREACH(mp, &g_classes, class) {
448 		LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
449 			LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
450 				if (!(pp->flags & G_PF_WITHER))
451 					continue;
452 				if (LIST_EMPTY(&pp->consumers))
453 					g_destroy_provider(pp);
454 				else
455 					result |= 1;
456 			}
457 			if (!(gp->flags & G_GEOM_WITHER))
458 				continue;
459 			LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
460 				if (LIST_EMPTY(&pp->consumers))
461 					g_destroy_provider(pp);
462 				else
463 					result |= 1;
464 			}
465 			LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp2) {
466 				if (cp->acr || cp->acw || cp->ace) {
467 					result |= 1;
468 					continue;
469 				}
470 				if (cp->provider != NULL)
471 					g_detach(cp);
472 				g_destroy_consumer(cp);
473 				result |= 2;
474 			}
475 			if (LIST_EMPTY(&gp->provider) &&
476 			    LIST_EMPTY(&gp->consumer))
477 				g_destroy_geom(gp);
478 			else
479 				result |= 1;
480 		}
481 	}
482 	return (result);
483 }
484 
485 struct g_consumer *
486 g_new_consumer(struct g_geom *gp)
487 {
488 	struct g_consumer *cp;
489 
490 	g_topology_assert();
491 	G_VALID_GEOM(gp);
492 	KASSERT(!(gp->flags & G_GEOM_WITHER),
493 	    ("g_new_consumer on WITHERing geom(%s) (class %s)",
494 	    gp->name, gp->class->name));
495 	KASSERT(gp->orphan != NULL,
496 	    ("g_new_consumer on geom(%s) (class %s) without orphan",
497 	    gp->name, gp->class->name));
498 
499 	cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO);
500 	cp->geom = gp;
501 	cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED,
502 	    DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
503 	LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
504 	return(cp);
505 }
506 
507 void
508 g_destroy_consumer(struct g_consumer *cp)
509 {
510 	struct g_geom *gp;
511 
512 	g_topology_assert();
513 	G_VALID_CONSUMER(cp);
514 	g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
515 	KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
516 	KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
517 	KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
518 	KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
519 	g_cancel_event(cp);
520 	gp = cp->geom;
521 	LIST_REMOVE(cp, consumer);
522 	devstat_remove_entry(cp->stat);
523 	g_free(cp);
524 	if (gp->flags & G_GEOM_WITHER)
525 		g_do_wither();
526 }
527 
528 static void
529 g_new_provider_event(void *arg, int flag)
530 {
531 	struct g_class *mp;
532 	struct g_provider *pp;
533 	struct g_consumer *cp;
534 
535 	g_topology_assert();
536 	if (flag == EV_CANCEL)
537 		return;
538 	if (g_shutdown)
539 		return;
540 	pp = arg;
541 	G_VALID_PROVIDER(pp);
542 	KASSERT(!(pp->flags & G_PF_WITHER),
543 	    ("g_new_provider_event but withered"));
544 	LIST_FOREACH(mp, &g_classes, class) {
545 		if (mp->taste == NULL)
546 			continue;
547 		LIST_FOREACH(cp, &pp->consumers, consumers)
548 			if (cp->geom->class == mp)
549 				break;
550 		if (cp != NULL)
551 			continue;
552 		mp->taste(mp, pp, 0);
553 		g_topology_assert();
554 	}
555 }
556 
557 
558 struct g_provider *
559 g_new_providerf(struct g_geom *gp, const char *fmt, ...)
560 {
561 	struct g_provider *pp;
562 	struct sbuf *sb;
563 	va_list ap;
564 
565 	g_topology_assert();
566 	G_VALID_GEOM(gp);
567 	KASSERT(gp->access != NULL,
568 	    ("new provider on geom(%s) without ->access (class %s)",
569 	    gp->name, gp->class->name));
570 	KASSERT(gp->start != NULL,
571 	    ("new provider on geom(%s) without ->start (class %s)",
572 	    gp->name, gp->class->name));
573 	KASSERT(!(gp->flags & G_GEOM_WITHER),
574 	    ("new provider on WITHERing geom(%s) (class %s)",
575 	    gp->name, gp->class->name));
576 	sb = sbuf_new_auto();
577 	va_start(ap, fmt);
578 	sbuf_vprintf(sb, fmt, ap);
579 	va_end(ap);
580 	sbuf_finish(sb);
581 	pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
582 	pp->name = (char *)(pp + 1);
583 	strcpy(pp->name, sbuf_data(sb));
584 	sbuf_delete(sb);
585 	LIST_INIT(&pp->consumers);
586 	pp->error = ENXIO;
587 	pp->geom = gp;
588 	pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED,
589 	    DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
590 	LIST_INSERT_HEAD(&gp->provider, pp, provider);
591 	g_post_event(g_new_provider_event, pp, M_WAITOK, pp, gp, NULL);
592 	return (pp);
593 }
594 
595 void
596 g_error_provider(struct g_provider *pp, int error)
597 {
598 
599 	/* G_VALID_PROVIDER(pp);  We may not have g_topology */
600 	pp->error = error;
601 }
602 
603 struct g_provider *
604 g_provider_by_name(char const *arg)
605 {
606 	struct g_class *cp;
607 	struct g_geom *gp;
608 	struct g_provider *pp;
609 
610 	LIST_FOREACH(cp, &g_classes, class) {
611 		LIST_FOREACH(gp, &cp->geom, geom) {
612 			LIST_FOREACH(pp, &gp->provider, provider) {
613 				if (!strcmp(arg, pp->name))
614 					return (pp);
615 			}
616 		}
617 	}
618 	return (NULL);
619 }
620 
621 void
622 g_destroy_provider(struct g_provider *pp)
623 {
624 	struct g_geom *gp;
625 
626 	g_topology_assert();
627 	G_VALID_PROVIDER(pp);
628 	KASSERT(LIST_EMPTY(&pp->consumers),
629 	    ("g_destroy_provider but attached"));
630 	KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
631 	KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
632 	KASSERT (pp->ace == 0, ("g_destroy_provider with ace"));
633 	g_cancel_event(pp);
634 	LIST_REMOVE(pp, provider);
635 	gp = pp->geom;
636 	devstat_remove_entry(pp->stat);
637 	g_free(pp);
638 	if ((gp->flags & G_GEOM_WITHER))
639 		g_do_wither();
640 }
641 
642 /*
643  * We keep the "geoms" list sorted by topological order (== increasing
644  * numerical rank) at all times.
645  * When an attach is done, the attaching geoms rank is invalidated
646  * and it is moved to the tail of the list.
647  * All geoms later in the sequence has their ranks reevaluated in
648  * sequence.  If we cannot assign rank to a geom because it's
649  * prerequisites do not have rank, we move that element to the tail
650  * of the sequence with invalid rank as well.
651  * At some point we encounter our original geom and if we stil fail
652  * to assign it a rank, there must be a loop and we fail back to
653  * g_attach() which detach again and calls redo_rank again
654  * to fix up the damage.
655  * It would be much simpler code wise to do it recursively, but we
656  * can't risk that on the kernel stack.
657  */
658 
659 static int
660 redo_rank(struct g_geom *gp)
661 {
662 	struct g_consumer *cp;
663 	struct g_geom *gp1, *gp2;
664 	int n, m;
665 
666 	g_topology_assert();
667 	G_VALID_GEOM(gp);
668 
669 	/* Invalidate this geoms rank and move it to the tail */
670 	gp1 = TAILQ_NEXT(gp, geoms);
671 	if (gp1 != NULL) {
672 		gp->rank = 0;
673 		TAILQ_REMOVE(&geoms, gp, geoms);
674 		TAILQ_INSERT_TAIL(&geoms, gp, geoms);
675 	} else {
676 		gp1 = gp;
677 	}
678 
679 	/* re-rank the rest of the sequence */
680 	for (; gp1 != NULL; gp1 = gp2) {
681 		gp1->rank = 0;
682 		m = 1;
683 		LIST_FOREACH(cp, &gp1->consumer, consumer) {
684 			if (cp->provider == NULL)
685 				continue;
686 			n = cp->provider->geom->rank;
687 			if (n == 0) {
688 				m = 0;
689 				break;
690 			} else if (n >= m)
691 				m = n + 1;
692 		}
693 		gp1->rank = m;
694 		gp2 = TAILQ_NEXT(gp1, geoms);
695 
696 		/* got a rank, moving on */
697 		if (m != 0)
698 			continue;
699 
700 		/* no rank to original geom means loop */
701 		if (gp == gp1)
702 			return (ELOOP);
703 
704 		/* no rank, put it at the end move on */
705 		TAILQ_REMOVE(&geoms, gp1, geoms);
706 		TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
707 	}
708 	return (0);
709 }
710 
711 int
712 g_attach(struct g_consumer *cp, struct g_provider *pp)
713 {
714 	int error;
715 
716 	g_topology_assert();
717 	G_VALID_CONSUMER(cp);
718 	G_VALID_PROVIDER(pp);
719 	g_trace(G_T_TOPOLOGY, "g_attach(%p, %p)", cp, pp);
720 	KASSERT(cp->provider == NULL, ("attach but attached"));
721 	cp->provider = pp;
722 	LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
723 	error = redo_rank(cp->geom);
724 	if (error) {
725 		LIST_REMOVE(cp, consumers);
726 		cp->provider = NULL;
727 		redo_rank(cp->geom);
728 	}
729 	return (error);
730 }
731 
732 void
733 g_detach(struct g_consumer *cp)
734 {
735 	struct g_provider *pp;
736 
737 	g_topology_assert();
738 	G_VALID_CONSUMER(cp);
739 	g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp);
740 	KASSERT(cp->provider != NULL, ("detach but not attached"));
741 	KASSERT(cp->acr == 0, ("detach but nonzero acr"));
742 	KASSERT(cp->acw == 0, ("detach but nonzero acw"));
743 	KASSERT(cp->ace == 0, ("detach but nonzero ace"));
744 	KASSERT(cp->nstart == cp->nend,
745 	    ("detach with active requests"));
746 	pp = cp->provider;
747 	LIST_REMOVE(cp, consumers);
748 	cp->provider = NULL;
749 	if (pp->geom->flags & G_GEOM_WITHER)
750 		g_do_wither();
751 	else if (pp->flags & G_PF_WITHER)
752 		g_do_wither();
753 	redo_rank(cp->geom);
754 }
755 
756 /*
757  * g_access()
758  *
759  * Access-check with delta values.  The question asked is "can provider
760  * "cp" change the access counters by the relative amounts dc[rwe] ?"
761  */
762 
763 int
764 g_access(struct g_consumer *cp, int dcr, int dcw, int dce)
765 {
766 	struct g_provider *pp;
767 	int pr,pw,pe;
768 	int error;
769 
770 	g_topology_assert();
771 	G_VALID_CONSUMER(cp);
772 	pp = cp->provider;
773 	KASSERT(pp != NULL, ("access but not attached"));
774 	G_VALID_PROVIDER(pp);
775 
776 	g_trace(G_T_ACCESS, "g_access(%p(%s), %d, %d, %d)",
777 	    cp, pp->name, dcr, dcw, dce);
778 
779 	KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
780 	KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
781 	KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
782 	KASSERT(dcr != 0 || dcw != 0 || dce != 0, ("NOP access request"));
783 	KASSERT(pp->geom->access != NULL, ("NULL geom->access"));
784 
785 	/*
786 	 * If our class cares about being spoiled, and we have been, we
787 	 * are probably just ahead of the event telling us that.  Fail
788 	 * now rather than having to unravel this later.
789 	 */
790 	if (cp->geom->spoiled != NULL && cp->spoiled &&
791 	    (dcr > 0 || dcw > 0 || dce > 0))
792 		return (ENXIO);
793 
794 	/*
795 	 * Figure out what counts the provider would have had, if this
796 	 * consumer had (r0w0e0) at this time.
797 	 */
798 	pr = pp->acr - cp->acr;
799 	pw = pp->acw - cp->acw;
800 	pe = pp->ace - cp->ace;
801 
802 	g_trace(G_T_ACCESS,
803     "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
804 	    dcr, dcw, dce,
805 	    cp->acr, cp->acw, cp->ace,
806 	    pp->acr, pp->acw, pp->ace,
807 	    pp, pp->name);
808 
809 	/* If foot-shooting is enabled, any open on rank#1 is OK */
810 	if ((g_debugflags & 16) && pp->geom->rank == 1)
811 		;
812 	/* If we try exclusive but already write: fail */
813 	else if (dce > 0 && pw > 0)
814 		return (EPERM);
815 	/* If we try write but already exclusive: fail */
816 	else if (dcw > 0 && pe > 0)
817 		return (EPERM);
818 	/* If we try to open more but provider is error'ed: fail */
819 	else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0)
820 		return (pp->error);
821 
822 	/* Ok then... */
823 
824 	error = pp->geom->access(pp, dcr, dcw, dce);
825 	KASSERT(dcr > 0 || dcw > 0 || dce > 0 || error == 0,
826 	    ("Geom provider %s::%s failed closing ->access()",
827 	    pp->geom->class->name, pp->name));
828 	if (!error) {
829 		/*
830 		 * If we open first write, spoil any partner consumers.
831 		 * If we close last write and provider is not errored,
832 		 * trigger re-taste.
833 		 */
834 		if (pp->acw == 0 && dcw != 0)
835 			g_spoil(pp, cp);
836 		else if (pp->acw != 0 && pp->acw == -dcw && pp->error == 0 &&
837 		    !(pp->geom->flags & G_GEOM_WITHER))
838 			g_post_event(g_new_provider_event, pp, M_WAITOK,
839 			    pp, NULL);
840 
841 		pp->acr += dcr;
842 		pp->acw += dcw;
843 		pp->ace += dce;
844 		cp->acr += dcr;
845 		cp->acw += dcw;
846 		cp->ace += dce;
847 		if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)
848 			KASSERT(pp->sectorsize > 0,
849 			    ("Provider %s lacks sectorsize", pp->name));
850 	}
851 	return (error);
852 }
853 
854 int
855 g_handleattr_int(struct bio *bp, const char *attribute, int val)
856 {
857 
858 	return (g_handleattr(bp, attribute, &val, sizeof val));
859 }
860 
861 int
862 g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val)
863 {
864 
865 	return (g_handleattr(bp, attribute, &val, sizeof val));
866 }
867 
868 int
869 g_handleattr_str(struct bio *bp, const char *attribute, const char *str)
870 {
871 
872 	return (g_handleattr(bp, attribute, str, 0));
873 }
874 
875 int
876 g_handleattr(struct bio *bp, const char *attribute, const void *val, int len)
877 {
878 	int error = 0;
879 
880 	if (strcmp(bp->bio_attribute, attribute))
881 		return (0);
882 	if (len == 0) {
883 		bzero(bp->bio_data, bp->bio_length);
884 		if (strlcpy(bp->bio_data, val, bp->bio_length) >=
885 		    bp->bio_length) {
886 			printf("%s: %s bio_length %jd len %zu -> EFAULT\n",
887 			    __func__, bp->bio_to->name,
888 			    (intmax_t)bp->bio_length, strlen(val));
889 			error = EFAULT;
890 		}
891 	} else if (bp->bio_length == len) {
892 		bcopy(val, bp->bio_data, len);
893 	} else {
894 		printf("%s: %s bio_length %jd len %d -> EFAULT\n", __func__,
895 		    bp->bio_to->name, (intmax_t)bp->bio_length, len);
896 		error = EFAULT;
897 	}
898 	if (error == 0)
899 		bp->bio_completed = bp->bio_length;
900 	g_io_deliver(bp, error);
901 	return (1);
902 }
903 
904 int
905 g_std_access(struct g_provider *pp,
906 	int dr __unused, int dw __unused, int de __unused)
907 {
908 
909 	g_topology_assert();
910 	G_VALID_PROVIDER(pp);
911         return (0);
912 }
913 
914 void
915 g_std_done(struct bio *bp)
916 {
917 	struct bio *bp2;
918 
919 	bp2 = bp->bio_parent;
920 	if (bp2->bio_error == 0)
921 		bp2->bio_error = bp->bio_error;
922 	bp2->bio_completed += bp->bio_completed;
923 	g_destroy_bio(bp);
924 	bp2->bio_inbed++;
925 	if (bp2->bio_children == bp2->bio_inbed)
926 		g_io_deliver(bp2, bp2->bio_error);
927 }
928 
929 /* XXX: maybe this is only g_slice_spoiled */
930 
931 void
932 g_std_spoiled(struct g_consumer *cp)
933 {
934 	struct g_geom *gp;
935 	struct g_provider *pp;
936 
937 	g_topology_assert();
938 	G_VALID_CONSUMER(cp);
939 	g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
940 	g_detach(cp);
941 	gp = cp->geom;
942 	LIST_FOREACH(pp, &gp->provider, provider)
943 		g_orphan_provider(pp, ENXIO);
944 	g_destroy_consumer(cp);
945 	if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
946 		g_destroy_geom(gp);
947 	else
948 		gp->flags |= G_GEOM_WITHER;
949 }
950 
951 /*
952  * Spoiling happens when a provider is opened for writing, but consumers
953  * which are configured by in-band data are attached (slicers for instance).
954  * Since the write might potentially change the in-band data, such consumers
955  * need to re-evaluate their existence after the writing session closes.
956  * We do this by (offering to) tear them down when the open for write happens
957  * in return for a re-taste when it closes again.
958  * Together with the fact that such consumers grab an 'e' bit whenever they
959  * are open, regardless of mode, this ends up DTRT.
960  */
961 
962 static void
963 g_spoil_event(void *arg, int flag)
964 {
965 	struct g_provider *pp;
966 	struct g_consumer *cp, *cp2;
967 
968 	g_topology_assert();
969 	if (flag == EV_CANCEL)
970 		return;
971 	pp = arg;
972 	G_VALID_PROVIDER(pp);
973 	for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) {
974 		cp2 = LIST_NEXT(cp, consumers);
975 		if (!cp->spoiled)
976 			continue;
977 		cp->spoiled = 0;
978 		if (cp->geom->spoiled == NULL)
979 			continue;
980 		cp->geom->spoiled(cp);
981 		g_topology_assert();
982 	}
983 }
984 
985 void
986 g_spoil(struct g_provider *pp, struct g_consumer *cp)
987 {
988 	struct g_consumer *cp2;
989 
990 	g_topology_assert();
991 	G_VALID_PROVIDER(pp);
992 	G_VALID_CONSUMER(cp);
993 
994 	LIST_FOREACH(cp2, &pp->consumers, consumers) {
995 		if (cp2 == cp)
996 			continue;
997 /*
998 		KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
999 		KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
1000 */
1001 		KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
1002 		cp2->spoiled++;
1003 	}
1004 	g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL);
1005 }
1006 
1007 int
1008 g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len)
1009 {
1010 	int error, i;
1011 
1012 	i = len;
1013 	error = g_io_getattr(attr, cp, &i, var);
1014 	if (error)
1015 		return (error);
1016 	if (i != len)
1017 		return (EINVAL);
1018 	return (0);
1019 }
1020 
1021 static int
1022 g_get_device_prefix_len(const char *name)
1023 {
1024 	int len;
1025 
1026 	if (strncmp(name, "ada", 3) == 0)
1027 		len = 3;
1028 	else if (strncmp(name, "ad", 2) == 0)
1029 		len = 2;
1030 	else
1031 		return (0);
1032 	if (name[len] < '0' || name[len] > '9')
1033 		return (0);
1034 	do {
1035 		len++;
1036 	} while (name[len] >= '0' && name[len] <= '9');
1037 	return (len);
1038 }
1039 
1040 int
1041 g_compare_names(const char *namea, const char *nameb)
1042 {
1043 	int deva, devb;
1044 
1045 	if (strcmp(namea, nameb) == 0)
1046 		return (1);
1047 	deva = g_get_device_prefix_len(namea);
1048 	if (deva == 0)
1049 		return (0);
1050 	devb = g_get_device_prefix_len(nameb);
1051 	if (devb == 0)
1052 		return (0);
1053 	if (strcmp(namea + deva, nameb + devb) == 0)
1054 		return (1);
1055 	return (0);
1056 }
1057 
1058 #if defined(DIAGNOSTIC) || defined(DDB)
1059 /*
1060  * This function walks the mesh and returns a non-zero integer if it
1061  * finds the argument pointer is an object. The return value indicates
1062  * which type of object it is believed to be. If topology is not locked,
1063  * this function is potentially dangerous, but we don't assert that the
1064  * topology lock is held when called from debugger.
1065  */
1066 int
1067 g_valid_obj(void const *ptr)
1068 {
1069 	struct g_class *mp;
1070 	struct g_geom *gp;
1071 	struct g_consumer *cp;
1072 	struct g_provider *pp;
1073 
1074 #ifdef KDB
1075 	if (kdb_active == 0)
1076 #endif
1077 		g_topology_assert();
1078 
1079 	LIST_FOREACH(mp, &g_classes, class) {
1080 		if (ptr == mp)
1081 			return (1);
1082 		LIST_FOREACH(gp, &mp->geom, geom) {
1083 			if (ptr == gp)
1084 				return (2);
1085 			LIST_FOREACH(cp, &gp->consumer, consumer)
1086 				if (ptr == cp)
1087 					return (3);
1088 			LIST_FOREACH(pp, &gp->provider, provider)
1089 				if (ptr == pp)
1090 					return (4);
1091 		}
1092 	}
1093 	return(0);
1094 }
1095 #endif
1096 
1097 #ifdef DDB
1098 
1099 #define	gprintf(...)	do {						\
1100 	db_printf("%*s", indent, "");					\
1101 	db_printf(__VA_ARGS__);						\
1102 } while (0)
1103 #define	gprintln(...)	do {						\
1104 	gprintf(__VA_ARGS__);						\
1105 	db_printf("\n");						\
1106 } while (0)
1107 
1108 #define	ADDFLAG(obj, flag, sflag)	do {				\
1109 	if ((obj)->flags & (flag)) {					\
1110 		if (comma)						\
1111 			strlcat(str, ",", size);			\
1112 		strlcat(str, (sflag), size);				\
1113 		comma = 1;						\
1114 	}								\
1115 } while (0)
1116 
1117 static char *
1118 provider_flags_to_string(struct g_provider *pp, char *str, size_t size)
1119 {
1120 	int comma = 0;
1121 
1122 	bzero(str, size);
1123 	if (pp->flags == 0) {
1124 		strlcpy(str, "NONE", size);
1125 		return (str);
1126 	}
1127 	ADDFLAG(pp, G_PF_CANDELETE, "G_PF_CANDELETE");
1128 	ADDFLAG(pp, G_PF_WITHER, "G_PF_WITHER");
1129 	ADDFLAG(pp, G_PF_ORPHAN, "G_PF_ORPHAN");
1130 	return (str);
1131 }
1132 
1133 static char *
1134 geom_flags_to_string(struct g_geom *gp, char *str, size_t size)
1135 {
1136 	int comma = 0;
1137 
1138 	bzero(str, size);
1139 	if (gp->flags == 0) {
1140 		strlcpy(str, "NONE", size);
1141 		return (str);
1142 	}
1143 	ADDFLAG(gp, G_GEOM_WITHER, "G_GEOM_WITHER");
1144 	return (str);
1145 }
1146 static void
1147 db_show_geom_consumer(int indent, struct g_consumer *cp)
1148 {
1149 
1150 	if (indent == 0) {
1151 		gprintln("consumer: %p", cp);
1152 		gprintln("  class:    %s (%p)", cp->geom->class->name,
1153 		    cp->geom->class);
1154 		gprintln("  geom:     %s (%p)", cp->geom->name, cp->geom);
1155 		if (cp->provider == NULL)
1156 			gprintln("  provider: none");
1157 		else {
1158 			gprintln("  provider: %s (%p)", cp->provider->name,
1159 			    cp->provider);
1160 		}
1161 		gprintln("  access:   r%dw%de%d", cp->acr, cp->acw, cp->ace);
1162 		gprintln("  spoiled:  %d", cp->spoiled);
1163 		gprintln("  nstart:   %u", cp->nstart);
1164 		gprintln("  nend:     %u", cp->nend);
1165 	} else {
1166 		gprintf("consumer: %p (%s), access=r%dw%de%d", cp,
1167 		    cp->provider != NULL ? cp->provider->name : "none",
1168 		    cp->acr, cp->acw, cp->ace);
1169 		if (cp->spoiled)
1170 			db_printf(", spoiled=%d", cp->spoiled);
1171 		db_printf("\n");
1172 	}
1173 }
1174 
1175 static void
1176 db_show_geom_provider(int indent, struct g_provider *pp)
1177 {
1178 	struct g_consumer *cp;
1179 	char flags[64];
1180 
1181 	if (indent == 0) {
1182 		gprintln("provider: %s (%p)", pp->name, pp);
1183 		gprintln("  class:        %s (%p)", pp->geom->class->name,
1184 		    pp->geom->class);
1185 		gprintln("  geom:         %s (%p)", pp->geom->name, pp->geom);
1186 		gprintln("  mediasize:    %jd", (intmax_t)pp->mediasize);
1187 		gprintln("  sectorsize:   %u", pp->sectorsize);
1188 		gprintln("  stripesize:   %u", pp->stripesize);
1189 		gprintln("  stripeoffset: %u", pp->stripeoffset);
1190 		gprintln("  access:       r%dw%de%d", pp->acr, pp->acw,
1191 		    pp->ace);
1192 		gprintln("  flags:        %s (0x%04x)",
1193 		    provider_flags_to_string(pp, flags, sizeof(flags)),
1194 		    pp->flags);
1195 		gprintln("  error:        %d", pp->error);
1196 		gprintln("  nstart:       %u", pp->nstart);
1197 		gprintln("  nend:         %u", pp->nend);
1198 		if (LIST_EMPTY(&pp->consumers))
1199 			gprintln("  consumers:    none");
1200 	} else {
1201 		gprintf("provider: %s (%p), access=r%dw%de%d",
1202 		    pp->name, pp, pp->acr, pp->acw, pp->ace);
1203 		if (pp->flags != 0) {
1204 			db_printf(", flags=%s (0x%04x)",
1205 			    provider_flags_to_string(pp, flags, sizeof(flags)),
1206 			    pp->flags);
1207 		}
1208 		db_printf("\n");
1209 	}
1210 	if (!LIST_EMPTY(&pp->consumers)) {
1211 		LIST_FOREACH(cp, &pp->consumers, consumers) {
1212 			db_show_geom_consumer(indent + 2, cp);
1213 			if (db_pager_quit)
1214 				break;
1215 		}
1216 	}
1217 }
1218 
1219 static void
1220 db_show_geom_geom(int indent, struct g_geom *gp)
1221 {
1222 	struct g_provider *pp;
1223 	struct g_consumer *cp;
1224 	char flags[64];
1225 
1226 	if (indent == 0) {
1227 		gprintln("geom: %s (%p)", gp->name, gp);
1228 		gprintln("  class:     %s (%p)", gp->class->name, gp->class);
1229 		gprintln("  flags:     %s (0x%04x)",
1230 		    geom_flags_to_string(gp, flags, sizeof(flags)), gp->flags);
1231 		gprintln("  rank:      %d", gp->rank);
1232 		if (LIST_EMPTY(&gp->provider))
1233 			gprintln("  providers: none");
1234 		if (LIST_EMPTY(&gp->consumer))
1235 			gprintln("  consumers: none");
1236 	} else {
1237 		gprintf("geom: %s (%p), rank=%d", gp->name, gp, gp->rank);
1238 		if (gp->flags != 0) {
1239 			db_printf(", flags=%s (0x%04x)",
1240 			    geom_flags_to_string(gp, flags, sizeof(flags)),
1241 			    gp->flags);
1242 		}
1243 		db_printf("\n");
1244 	}
1245 	if (!LIST_EMPTY(&gp->provider)) {
1246 		LIST_FOREACH(pp, &gp->provider, provider) {
1247 			db_show_geom_provider(indent + 2, pp);
1248 			if (db_pager_quit)
1249 				break;
1250 		}
1251 	}
1252 	if (!LIST_EMPTY(&gp->consumer)) {
1253 		LIST_FOREACH(cp, &gp->consumer, consumer) {
1254 			db_show_geom_consumer(indent + 2, cp);
1255 			if (db_pager_quit)
1256 				break;
1257 		}
1258 	}
1259 }
1260 
1261 static void
1262 db_show_geom_class(struct g_class *mp)
1263 {
1264 	struct g_geom *gp;
1265 
1266 	db_printf("class: %s (%p)\n", mp->name, mp);
1267 	LIST_FOREACH(gp, &mp->geom, geom) {
1268 		db_show_geom_geom(2, gp);
1269 		if (db_pager_quit)
1270 			break;
1271 	}
1272 }
1273 
1274 /*
1275  * Print the GEOM topology or the given object.
1276  */
1277 DB_SHOW_COMMAND(geom, db_show_geom)
1278 {
1279 	struct g_class *mp;
1280 
1281 	if (!have_addr) {
1282 		/* No address given, print the entire topology. */
1283 		LIST_FOREACH(mp, &g_classes, class) {
1284 			db_show_geom_class(mp);
1285 			db_printf("\n");
1286 			if (db_pager_quit)
1287 				break;
1288 		}
1289 	} else {
1290 		switch (g_valid_obj((void *)addr)) {
1291 		case 1:
1292 			db_show_geom_class((struct g_class *)addr);
1293 			break;
1294 		case 2:
1295 			db_show_geom_geom(0, (struct g_geom *)addr);
1296 			break;
1297 		case 3:
1298 			db_show_geom_consumer(0, (struct g_consumer *)addr);
1299 			break;
1300 		case 4:
1301 			db_show_geom_provider(0, (struct g_provider *)addr);
1302 			break;
1303 		default:
1304 			db_printf("Not a GEOM object.\n");
1305 			break;
1306 		}
1307 	}
1308 }
1309 
1310 static void
1311 db_print_bio_cmd(struct bio *bp)
1312 {
1313 	db_printf("  cmd: ");
1314 	switch (bp->bio_cmd) {
1315 	case BIO_READ: db_printf("BIO_READ"); break;
1316 	case BIO_WRITE: db_printf("BIO_WRITE"); break;
1317 	case BIO_DELETE: db_printf("BIO_DELETE"); break;
1318 	case BIO_GETATTR: db_printf("BIO_GETATTR"); break;
1319 	case BIO_FLUSH: db_printf("BIO_FLUSH"); break;
1320 	case BIO_CMD0: db_printf("BIO_CMD0"); break;
1321 	case BIO_CMD1: db_printf("BIO_CMD1"); break;
1322 	case BIO_CMD2: db_printf("BIO_CMD2"); break;
1323 	default: db_printf("UNKNOWN"); break;
1324 	}
1325 	db_printf("\n");
1326 }
1327 
1328 static void
1329 db_print_bio_flags(struct bio *bp)
1330 {
1331 	int comma;
1332 
1333 	comma = 0;
1334 	db_printf("  flags: ");
1335 	if (bp->bio_flags & BIO_ERROR) {
1336 		db_printf("BIO_ERROR");
1337 		comma = 1;
1338 	}
1339 	if (bp->bio_flags & BIO_DONE) {
1340 		db_printf("%sBIO_DONE", (comma ? ", " : ""));
1341 		comma = 1;
1342 	}
1343 	if (bp->bio_flags & BIO_ONQUEUE)
1344 		db_printf("%sBIO_ONQUEUE", (comma ? ", " : ""));
1345 	db_printf("\n");
1346 }
1347 
1348 /*
1349  * Print useful information in a BIO
1350  */
1351 DB_SHOW_COMMAND(bio, db_show_bio)
1352 {
1353 	struct bio *bp;
1354 
1355 	if (have_addr) {
1356 		bp = (struct bio *)addr;
1357 		db_printf("BIO %p\n", bp);
1358 		db_print_bio_cmd(bp);
1359 		db_print_bio_flags(bp);
1360 		db_printf("  cflags: 0x%hhx\n", bp->bio_cflags);
1361 		db_printf("  pflags: 0x%hhx\n", bp->bio_pflags);
1362 		db_printf("  offset: %jd\n", (intmax_t)bp->bio_offset);
1363 		db_printf("  length: %jd\n", (intmax_t)bp->bio_length);
1364 		db_printf("  bcount: %ld\n", bp->bio_bcount);
1365 		db_printf("  resid: %ld\n", bp->bio_resid);
1366 		db_printf("  completed: %jd\n", (intmax_t)bp->bio_completed);
1367 		db_printf("  children: %u\n", bp->bio_children);
1368 		db_printf("  inbed: %u\n", bp->bio_inbed);
1369 		db_printf("  error: %d\n", bp->bio_error);
1370 		db_printf("  parent: %p\n", bp->bio_parent);
1371 		db_printf("  driver1: %p\n", bp->bio_driver1);
1372 		db_printf("  driver2: %p\n", bp->bio_driver2);
1373 		db_printf("  caller1: %p\n", bp->bio_caller1);
1374 		db_printf("  caller2: %p\n", bp->bio_caller2);
1375 		db_printf("  bio_from: %p\n", bp->bio_from);
1376 		db_printf("  bio_to: %p\n", bp->bio_to);
1377 	}
1378 }
1379 
1380 #undef	gprintf
1381 #undef	gprintln
1382 #undef	ADDFLAG
1383 
1384 #endif	/* DDB */
1385