xref: /freebsd/sys/geom/geom_subr.c (revision e805e8f0e8f9f762bfb5bffd72380a1b101b1a8b)
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  * $FreeBSD$
36  */
37 
38 
39 #include <sys/param.h>
40 #ifndef _KERNEL
41 #include <stdio.h>
42 #include <unistd.h>
43 #include <stdlib.h>
44 #include <signal.h>
45 #include <string.h>
46 #include <err.h>
47 #else
48 #include <sys/systm.h>
49 #include <sys/kernel.h>
50 #include <sys/malloc.h>
51 #include <sys/bio.h>
52 #include <sys/sysctl.h>
53 #include <sys/proc.h>
54 #include <sys/kthread.h>
55 #include <sys/lock.h>
56 #include <sys/mutex.h>
57 #endif
58 #include <sys/errno.h>
59 #include <sys/sbuf.h>
60 #include <geom/geom.h>
61 #include <machine/stdarg.h>
62 
63 struct class_list_head g_classs = LIST_HEAD_INITIALIZER(g_classs);
64 static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms);
65 static int g_nproviders;
66 char *g_wait_event, *g_wait_up, *g_wait_down, *g_wait_sim;
67 
68 static int g_ignition;
69 
70 void
71 g_add_class(struct g_class *mp)
72 {
73 
74 	if (!g_ignition) {
75 		g_ignition++;
76 		g_init();
77 	}
78 	g_topology_lock();
79 	g_trace(G_T_TOPOLOGY, "g_add_class(%s)", mp->name);
80 	LIST_INIT(&mp->geom);
81 	LIST_INSERT_HEAD(&g_classs, mp, class);
82 	if (g_nproviders > 0)
83 		g_post_event(EV_NEW_CLASS, mp, NULL, NULL, NULL);
84 	g_topology_unlock();
85 }
86 
87 struct g_geom *
88 g_new_geomf(struct g_class *mp, char *fmt, ...)
89 {
90 	struct g_geom *gp;
91 	va_list ap;
92 	struct sbuf *sb;
93 
94 	g_topology_assert();
95 	va_start(ap, fmt);
96 	mtx_lock(&Giant);
97 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
98 	sbuf_vprintf(sb, fmt, ap);
99 	sbuf_finish(sb);
100 	mtx_unlock(&Giant);
101 	gp = g_malloc(sizeof *gp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
102 	gp->name = (char *)(gp + 1);
103 	gp->class = mp;
104 	gp->rank = 1;
105 	LIST_INIT(&gp->consumer);
106 	LIST_INIT(&gp->provider);
107 	LIST_INSERT_HEAD(&mp->geom, gp, geom);
108 	TAILQ_INSERT_HEAD(&geoms, gp, geoms);
109 	strcpy(gp->name, sbuf_data(sb));
110 	sbuf_delete(sb);
111 	return (gp);
112 }
113 
114 void
115 g_destroy_geom(struct g_geom *gp)
116 {
117 
118 	g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
119 	g_topology_assert();
120 	KASSERT(gp->event == NULL, ("g_destroy_geom() with event"));
121 	KASSERT(LIST_EMPTY(&gp->consumer),
122 	    ("g_destroy_geom(%s) with consumer(s) [%p]",
123 	    gp->name, LIST_FIRST(&gp->consumer)));
124 	KASSERT(LIST_EMPTY(&gp->provider),
125 	    ("g_destroy_geom(%s) with provider(s) [%p]",
126 	    gp->name, LIST_FIRST(&gp->consumer)));
127 	LIST_REMOVE(gp, geom);
128 	TAILQ_REMOVE(&geoms, gp, geoms);
129 	g_free(gp);
130 }
131 
132 struct g_consumer *
133 g_new_consumer(struct g_geom *gp)
134 {
135 	struct g_consumer *cp;
136 
137 	g_topology_assert();
138 	KASSERT(gp->class->orphan != NULL,
139 	    ("g_new_consumer on class(%s) without orphan", gp->class->name));
140 
141 	cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO);
142 	cp->geom = gp;
143 	LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
144 	return(cp);
145 }
146 
147 void
148 g_destroy_consumer(struct g_consumer *cp)
149 {
150 
151 	g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
152 	g_topology_assert();
153 	KASSERT(cp->event == NULL, ("g_destroy_consumer() with event"));
154 	KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
155 	KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
156 	KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
157 	KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
158 	LIST_REMOVE(cp, consumer);
159 	g_free(cp);
160 }
161 
162 struct g_provider *
163 g_new_providerf(struct g_geom *gp, char *fmt, ...)
164 {
165 	struct g_provider *pp;
166 	struct sbuf *sb;
167 	va_list ap;
168 
169 	g_topology_assert();
170 	va_start(ap, fmt);
171 	mtx_lock(&Giant);
172 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
173 	sbuf_vprintf(sb, fmt, ap);
174 	sbuf_finish(sb);
175 	mtx_unlock(&Giant);
176 	pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
177 	pp->name = (char *)(pp + 1);
178 	strcpy(pp->name, sbuf_data(sb));
179 	sbuf_delete(sb);
180 	LIST_INIT(&pp->consumers);
181 	pp->error = ENXIO;
182 	pp->geom = gp;
183 	LIST_INSERT_HEAD(&gp->provider, pp, provider);
184 	g_nproviders++;
185 	g_post_event(EV_NEW_PROVIDER, NULL, NULL, pp, NULL);
186 	return (pp);
187 }
188 
189 void
190 g_error_provider(struct g_provider *pp, int error)
191 {
192 
193 	pp->error = error;
194 }
195 
196 
197 void
198 g_destroy_provider(struct g_provider *pp)
199 {
200 	struct g_geom *gp;
201 	struct g_consumer *cp;
202 
203 	g_topology_assert();
204 	KASSERT(pp->event == NULL, ("g_destroy_provider() with event"));
205 	KASSERT(LIST_EMPTY(&pp->consumers),
206 	    ("g_destroy_provider but attached"));
207 	KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
208 	KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
209 	KASSERT (pp->acw == 0, ("g_destroy_provider with ace"));
210 	g_nproviders--;
211 	LIST_REMOVE(pp, provider);
212 	gp = pp->geom;
213 	g_free(pp);
214 	if (!(gp->flags & G_GEOM_WITHER))
215 		return;
216 	if (!LIST_EMPTY(&gp->provider))
217 		return;
218 	for (;;) {
219 		cp = LIST_FIRST(&gp->consumer);
220 		if (cp == NULL)
221 			break;
222 		g_dettach(cp);
223 		g_destroy_consumer(cp);
224 	}
225 	g_destroy_geom(gp);
226 }
227 
228 /*
229  * We keep the "geoms" list sorted by topological order (== increasing
230  * numerical rank) at all times.
231  * When an attach is done, the attaching geoms rank is invalidated
232  * and it is moved to the tail of the list.
233  * All geoms later in the sequence has their ranks reevaluated in
234  * sequence.  If we cannot assign rank to a geom because it's
235  * prerequisites do not have rank, we move that element to the tail
236  * of the sequence with invalid rank as well.
237  * At some point we encounter our original geom and if we stil fail
238  * to assign it a rank, there must be a loop and we fail back to
239  * g_attach() which dettach again and calls redo_rank again
240  * to fix up the damage.
241  * It would be much simpler code wise to do it recursively, but we
242  * can't risk that on the kernel stack.
243  */
244 
245 static int
246 redo_rank(struct g_geom *gp)
247 {
248 	struct g_consumer *cp;
249 	struct g_geom *gp1, *gp2;
250 	int n, m;
251 
252 	g_topology_assert();
253 
254 	/* Invalidate this geoms rank and move it to the tail */
255 	gp1 = TAILQ_NEXT(gp, geoms);
256 	if (gp1 != NULL) {
257 		gp->rank = 0;
258 		TAILQ_REMOVE(&geoms, gp, geoms);
259 		TAILQ_INSERT_TAIL(&geoms, gp, geoms);
260 	} else {
261 		gp1 = gp;
262 	}
263 
264 	/* re-rank the rest of the sequence */
265 	for (; gp1 != NULL; gp1 = gp2) {
266 		gp1->rank = 0;
267 		m = 1;
268 		LIST_FOREACH(cp, &gp1->consumer, consumer) {
269 			if (cp->provider == NULL)
270 				continue;
271 			n = cp->provider->geom->rank;
272 			if (n == 0) {
273 				m = 0;
274 				break;
275 			} else if (n >= m)
276 				m = n + 1;
277 		}
278 		gp1->rank = m;
279 		gp2 = TAILQ_NEXT(gp1, geoms);
280 
281 		/* got a rank, moving on */
282 		if (m != 0)
283 			continue;
284 
285 		/* no rank to original geom means loop */
286 		if (gp == gp1) {
287 			return (ELOOP);
288 
289 		/* no rank, put it at the end move on */
290 		TAILQ_REMOVE(&geoms, gp1, geoms);
291 		TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
292 		}
293 	}
294 	return (0);
295 }
296 
297 int
298 g_attach(struct g_consumer *cp, struct g_provider *pp)
299 {
300 	int error;
301 
302 	g_topology_assert();
303 	KASSERT(cp->provider == NULL, ("attach but attached"));
304 	cp->provider = pp;
305 	LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
306 	error = redo_rank(cp->geom);
307 	if (error) {
308 		LIST_REMOVE(cp, consumers);
309 		cp->provider = NULL;
310 		redo_rank(cp->geom);
311 	}
312 	return (error);
313 }
314 
315 void
316 g_dettach(struct g_consumer *cp)
317 {
318 	struct g_provider *pp;
319 
320 	g_trace(G_T_TOPOLOGY, "g_dettach(%p)", cp);
321 	KASSERT(cp != (void*)0xd0d0d0d0, ("ARGH!"));
322 	g_topology_assert();
323 	KASSERT(cp->provider != NULL, ("dettach but not attached"));
324 	KASSERT(cp->acr == 0, ("dettach but nonzero acr"));
325 	KASSERT(cp->acw == 0, ("dettach but nonzero acw"));
326 	KASSERT(cp->ace == 0, ("dettach but nonzero ace"));
327 	KASSERT(cp->biocount == 0, ("dettach but nonzero biocount"));
328 	pp = cp->provider;
329 	LIST_REMOVE(cp, consumers);
330 	cp->provider = NULL;
331 	if (LIST_EMPTY(&pp->consumers)) {
332 		if (pp->geom->flags & G_GEOM_WITHER)
333 			g_destroy_provider(pp);
334 	}
335 	redo_rank(cp->geom);
336 }
337 
338 
339 /*
340  * g_access_abs()
341  *
342  * Access-check with absolute new values:  Just fall through
343  * and use the relative version.
344  */
345 int
346 g_access_abs(struct g_consumer *cp, int acr, int acw, int ace)
347 {
348 
349 	g_topology_assert();
350 	return(g_access_rel(cp,
351 		acr - cp->acr,
352 		acw - cp->acw,
353 		ace - cp->ace));
354 }
355 
356 /*
357  * g_access_rel()
358  *
359  * Access-check with delta values.  The question asked is "can provider
360  * "cp" change the access counters by the relative amounts dc[rwe] ?"
361  */
362 
363 int
364 g_access_rel(struct g_consumer *cp, int dcr, int dcw, int dce)
365 {
366 	struct g_provider *pp;
367 	int pr,pw,pe;
368 	int error;
369 
370 	pp = cp->provider;
371 
372 	g_trace(G_T_ACCESS, "g_access_rel(%p(%s), %d, %d, %d)",
373 	    cp, pp->name, dcr, dcw, dce);
374 
375 	g_topology_assert();
376 	KASSERT(cp->provider != NULL, ("access but not attached"));
377 	KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
378 	KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
379 	KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
380 	KASSERT(pp->geom->class->access != NULL, ("NULL class->access"));
381 
382 	/*
383 	 * If our class cares about being spoiled, and we have been, we
384 	 * are probably just ahead of the event telling us that.  Fail
385 	 * now rather than having to unravel this later.
386 	 */
387 	if (cp->geom->spoiled != NULL && cp->spoiled) {
388 		KASSERT(dcr >= 0, ("spoiled but dcr = %d", dcr));
389 		KASSERT(dcw >= 0, ("spoiled but dce = %d", dcw));
390 		KASSERT(dce >= 0, ("spoiled but dcw = %d", dce));
391 		KASSERT(cp->acr == 0, ("spoiled but cp->acr = %d", cp->acr));
392 		KASSERT(cp->acw == 0, ("spoiled but cp->acw = %d", cp->acw));
393 		KASSERT(cp->ace == 0, ("spoiled but cp->ace = %d", cp->ace));
394 		return(ENXIO);
395 	}
396 
397 	/*
398 	 * Figure out what counts the provider would have had, if this
399 	 * consumer had (r0w0e0) at this time.
400 	 */
401 	pr = pp->acr - cp->acr;
402 	pw = pp->acw - cp->acw;
403 	pe = pp->ace - cp->ace;
404 
405 	g_trace(G_T_ACCESS,
406     "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
407 	    dcr, dcw, dce,
408 	    cp->acr, cp->acw, cp->ace,
409 	    pp->acr, pp->acw, pp->ace,
410 	    pp, pp->name);
411 
412 	/* If we try exclusive but already write: fail */
413 	if (dce > 0 && pw > 0)
414 		return (EPERM);
415 	/* If we try write but already exclusive: fail */
416 	if (dcw > 0 && pe > 0)
417 		return (EPERM);
418 	/* If we try to open more but provider is error'ed: fail */
419 	if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0)
420 		return (pp->error);
421 
422 	/* Ok then... */
423 
424 	/*
425 	 * If we open first write, spoil any partner consumers.
426 	 * If we close last write, trigger re-taste.
427 	 */
428 	if (pp->acw == 0 && dcw != 0)
429 		g_spoil(pp, cp);
430 	else if (pp->acw != 0 && pp->acw == -dcw && !(pp->geom->flags & G_GEOM_WITHER))
431 		g_post_event(EV_NEW_PROVIDER, NULL, NULL, pp, NULL);
432 
433 	error = pp->geom->class->access(pp, dcr, dcw, dce);
434 	if (!error) {
435 		pp->acr += dcr;
436 		pp->acw += dcw;
437 		pp->ace += dce;
438 		cp->acr += dcr;
439 		cp->acw += dcw;
440 		cp->ace += dce;
441 	}
442 	return (error);
443 }
444 
445 int
446 g_haveattr_int(struct bio *bp, char *attribute, int val)
447 {
448 
449 	return (g_haveattr(bp, attribute, &val, sizeof val));
450 }
451 
452 int
453 g_haveattr_off_t(struct bio *bp, char *attribute, off_t val)
454 {
455 
456 	return (g_haveattr(bp, attribute, &val, sizeof val));
457 }
458 
459 
460 int
461 g_haveattr(struct bio *bp, char *attribute, void *val, int len)
462 {
463 	int error;
464 
465 	if (strcmp(bp->bio_attribute, attribute))
466 		return (0);
467 	if (bp->bio_length != len) {
468 		printf("bio_length %lld len %d -> EFAULT\n", bp->bio_length, len);
469 		error = EFAULT;
470 	} else {
471 		error = 0;
472 		bcopy(val, bp->bio_data, len);
473 		bp->bio_completed = len;
474 	}
475 	bp->bio_error = error;
476 	g_io_deliver(bp);
477 	return (1);
478 }
479 
480 int
481 g_std_access(struct g_provider *pp __unused,
482 	int dr __unused, int dw __unused, int de __unused)
483 {
484 
485         return (0);
486 }
487 
488 void
489 g_std_done(struct bio *bp)
490 {
491 	struct bio *bp2;
492 
493 	bp2 = bp->bio_linkage;
494 	bp2->bio_error = bp->bio_error;
495 	bp2->bio_completed = bp->bio_completed;
496 	g_destroy_bio(bp);
497 	g_io_deliver(bp2);
498 }
499 
500 /* XXX: maybe this is only g_slice_spoiled */
501 
502 void
503 g_std_spoiled(struct g_consumer *cp)
504 {
505 	struct g_geom *gp;
506 	struct g_provider *pp;
507 
508 	g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
509 	g_topology_assert();
510 	g_dettach(cp);
511 	gp = cp->geom;
512 	LIST_FOREACH(pp, &gp->provider, provider)
513 		g_orphan_provider(pp, ENXIO);
514 	g_destroy_consumer(cp);
515 	if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
516 		g_destroy_geom(gp);
517 	else
518 		gp->flags |= G_GEOM_WITHER;
519 }
520 
521 /*
522  * Spoiling happens when a provider is opened for writing, but consumers
523  * which are configured by in-band data are attached (slicers for instance).
524  * Since the write might potentially change the in-band data, such consumers
525  * need to re-evaluate their existence after the writing session closes.
526  * We do this by (offering to) tear them down when the open for write happens
527  * in return for a re-taste when it closes again.
528  * Together with the fact that such consumers grab an 'e' bit whenever they
529  * are open, regardless of mode, this ends up DTRT.
530  */
531 
532 void
533 g_spoil(struct g_provider *pp, struct g_consumer *cp)
534 {
535 	struct g_consumer *cp2;
536 
537 	g_topology_assert();
538 
539 	LIST_FOREACH(cp2, &pp->consumers, consumers) {
540 		if (cp2 == cp)
541 			continue;
542 /*
543 		KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
544 		KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
545 */
546 		KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
547 		cp2->spoiled++;
548 	}
549 	g_post_event(EV_SPOILED, NULL, NULL, pp, cp);
550 }
551 
552 static struct g_class *
553 g_class_by_name(char *name)
554 {
555 	struct g_class *mp;
556 
557 	g_trace(G_T_TOPOLOGY, "g_class_by_name(%s)", name);
558 	g_topology_assert();
559 	LIST_FOREACH(mp, &g_classs, class)
560 		if (!strcmp(mp->name, name))
561 			return (mp);
562 	return (NULL);
563 }
564 
565 struct g_geom *
566 g_create_geomf(char *class, struct g_provider *pp, char *fmt, ...)
567 {
568 	va_list ap;
569 	struct sbuf *sb;
570 	char *s;
571 	struct g_class *mp;
572 	struct g_geom *gp;
573 
574 	g_trace(G_T_TOPOLOGY, "g_create_geom(%s, %p(%s))", class,
575 		pp, pp == NULL ? "" : pp->name);
576 	g_topology_assert();
577 	gp = NULL;
578 	mp = g_class_by_name(class);
579 	if (mp == NULL)
580 		return (NULL);
581 	if (fmt != NULL) {
582 		va_start(ap, fmt);
583 		mtx_lock(&Giant);
584 		sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
585 		sbuf_vprintf(sb, fmt, ap);
586 		sbuf_finish(sb);
587 		mtx_unlock(&Giant);
588 		s = sbuf_data(sb);
589 	} else {
590 		s = NULL;
591 	}
592 	if (pp != NULL)
593 		gp = mp->taste(mp, pp, NULL, G_TF_INSIST);
594 	if (gp == NULL && mp->create_geom == NULL)
595 		return (NULL);
596 	if (gp == NULL)
597 		gp = mp->create_geom(mp, pp, s);
598 	/* XXX: delete sbuf  */
599 	return (gp);
600 }
601 
602 struct g_geom *
603 g_insert_geom(char *class, struct g_consumer *cp)
604 {
605 	struct g_class *mp;
606 	struct g_geom *gp;
607 	struct g_provider *pp, *pp2;
608 	struct g_consumer *cp2;
609 	int error;
610 
611 	g_trace(G_T_TOPOLOGY, "g_insert_geomf(%s, %p)", class, cp);
612 	g_topology_assert();
613 	KASSERT(cp->provider != NULL, ("g_insert_geomf but not attached"));
614 	/* XXX: check for events ?? */
615 	mp = g_class_by_name(class);
616 	if (mp == NULL)
617 		return (NULL);
618 	if (mp->create_geom == NULL)
619 		return (NULL);
620 	pp = cp->provider;
621 	gp = mp->taste(mp, pp, NULL, G_TF_TRANSPARENT);
622 	if (gp == NULL)
623 		return (NULL);
624 	pp2 = LIST_FIRST(&gp->provider);
625 	cp2 = LIST_FIRST(&gp->consumer);
626 	cp2->acr += pp->acr;
627 	cp2->acw += pp->acw;
628 	cp2->ace += pp->ace;
629 	pp2->acr += pp->acr;
630 	pp2->acw += pp->acw;
631 	pp2->ace += pp->ace;
632 	LIST_REMOVE(cp, consumers);
633 	LIST_INSERT_HEAD(&pp2->consumers, cp, consumers);
634 	cp->provider = pp2;
635 	error = redo_rank(gp);
636 	KASSERT(error == 0, ("redo_rank failed in g_insert_geom"));
637 	return (gp);
638 }
639 
640