xref: /freebsd/sys/geom/nop/g_nop.c (revision 09d325677d53a12c79a43664ff29871e92247629)
1 /*-
2  * Copyright (c) 2004-2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/module.h>
34 #include <sys/lock.h>
35 #include <sys/mutex.h>
36 #include <sys/bio.h>
37 #include <sys/sbuf.h>
38 #include <sys/sysctl.h>
39 #include <sys/malloc.h>
40 #include <geom/geom.h>
41 #include <geom/nop/g_nop.h>
42 
43 
44 SYSCTL_DECL(_kern_geom);
45 static SYSCTL_NODE(_kern_geom, OID_AUTO, nop, CTLFLAG_RW, 0, "GEOM_NOP stuff");
46 static u_int g_nop_debug = 0;
47 SYSCTL_UINT(_kern_geom_nop, OID_AUTO, debug, CTLFLAG_RW, &g_nop_debug, 0,
48     "Debug level");
49 
50 static int g_nop_destroy(struct g_geom *gp, boolean_t force);
51 static int g_nop_destroy_geom(struct gctl_req *req, struct g_class *mp,
52     struct g_geom *gp);
53 static void g_nop_config(struct gctl_req *req, struct g_class *mp,
54     const char *verb);
55 static void g_nop_dumpconf(struct sbuf *sb, const char *indent,
56     struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp);
57 
58 struct g_class g_nop_class = {
59 	.name = G_NOP_CLASS_NAME,
60 	.version = G_VERSION,
61 	.ctlreq = g_nop_config,
62 	.destroy_geom = g_nop_destroy_geom
63 };
64 
65 
66 static void
67 g_nop_orphan(struct g_consumer *cp)
68 {
69 
70 	g_topology_assert();
71 	g_nop_destroy(cp->geom, 1);
72 }
73 
74 static void
75 g_nop_resize(struct g_consumer *cp)
76 {
77 	struct g_nop_softc *sc;
78 	struct g_geom *gp;
79 	struct g_provider *pp;
80 	off_t size;
81 
82 	g_topology_assert();
83 
84 	gp = cp->geom;
85 	sc = gp->softc;
86 
87 	if (sc->sc_explicitsize != 0)
88 		return;
89 	if (cp->provider->mediasize < sc->sc_offset) {
90 		g_nop_destroy(gp, 1);
91 		return;
92 	}
93 	size = cp->provider->mediasize - sc->sc_offset;
94 	LIST_FOREACH(pp, &gp->provider, provider)
95 		g_resize_provider(pp, size);
96 }
97 
98 static void
99 g_nop_start(struct bio *bp)
100 {
101 	struct g_nop_softc *sc;
102 	struct g_geom *gp;
103 	struct g_provider *pp;
104 	struct bio *cbp;
105 	u_int failprob = 0;
106 
107 	gp = bp->bio_to->geom;
108 	sc = gp->softc;
109 	G_NOP_LOGREQ(bp, "Request received.");
110 	mtx_lock(&sc->sc_lock);
111 	switch (bp->bio_cmd) {
112 	case BIO_READ:
113 		sc->sc_reads++;
114 		sc->sc_readbytes += bp->bio_length;
115 		failprob = sc->sc_rfailprob;
116 		break;
117 	case BIO_WRITE:
118 		sc->sc_writes++;
119 		sc->sc_wrotebytes += bp->bio_length;
120 		failprob = sc->sc_wfailprob;
121 		break;
122 	}
123 	mtx_unlock(&sc->sc_lock);
124 	if (failprob > 0) {
125 		u_int rval;
126 
127 		rval = arc4random() % 100;
128 		if (rval < failprob) {
129 			G_NOP_LOGREQLVL(1, bp, "Returning error=%d.", sc->sc_error);
130 			g_io_deliver(bp, sc->sc_error);
131 			return;
132 		}
133 	}
134 	cbp = g_clone_bio(bp);
135 	if (cbp == NULL) {
136 		g_io_deliver(bp, ENOMEM);
137 		return;
138 	}
139 	cbp->bio_done = g_std_done;
140 	cbp->bio_offset = bp->bio_offset + sc->sc_offset;
141 	pp = LIST_FIRST(&gp->provider);
142 	KASSERT(pp != NULL, ("NULL pp"));
143 	cbp->bio_to = pp;
144 	G_NOP_LOGREQ(cbp, "Sending request.");
145 	g_io_request(cbp, LIST_FIRST(&gp->consumer));
146 }
147 
148 static int
149 g_nop_access(struct g_provider *pp, int dr, int dw, int de)
150 {
151 	struct g_geom *gp;
152 	struct g_consumer *cp;
153 	int error;
154 
155 	gp = pp->geom;
156 	cp = LIST_FIRST(&gp->consumer);
157 	error = g_access(cp, dr, dw, de);
158 
159 	return (error);
160 }
161 
162 static int
163 g_nop_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
164     int ioerror, u_int rfailprob, u_int wfailprob, off_t offset, off_t size,
165     u_int secsize)
166 {
167 	struct g_nop_softc *sc;
168 	struct g_geom *gp;
169 	struct g_provider *newpp;
170 	struct g_consumer *cp;
171 	char name[64];
172 	int error;
173 	off_t explicitsize;
174 
175 	g_topology_assert();
176 
177 	gp = NULL;
178 	newpp = NULL;
179 	cp = NULL;
180 
181 	if ((offset % pp->sectorsize) != 0) {
182 		gctl_error(req, "Invalid offset for provider %s.", pp->name);
183 		return (EINVAL);
184 	}
185 	if ((size % pp->sectorsize) != 0) {
186 		gctl_error(req, "Invalid size for provider %s.", pp->name);
187 		return (EINVAL);
188 	}
189 	if (offset >= pp->mediasize) {
190 		gctl_error(req, "Invalid offset for provider %s.", pp->name);
191 		return (EINVAL);
192 	}
193 	explicitsize = size;
194 	if (size == 0)
195 		size = pp->mediasize - offset;
196 	if (offset + size > pp->mediasize) {
197 		gctl_error(req, "Invalid size for provider %s.", pp->name);
198 		return (EINVAL);
199 	}
200 	if (secsize == 0)
201 		secsize = pp->sectorsize;
202 	else if ((secsize % pp->sectorsize) != 0) {
203 		gctl_error(req, "Invalid secsize for provider %s.", pp->name);
204 		return (EINVAL);
205 	}
206 	if (secsize > MAXPHYS) {
207 		gctl_error(req, "secsize is too big.");
208 		return (EINVAL);
209 	}
210 	size -= size % secsize;
211 	snprintf(name, sizeof(name), "%s%s", pp->name, G_NOP_SUFFIX);
212 	LIST_FOREACH(gp, &mp->geom, geom) {
213 		if (strcmp(gp->name, name) == 0) {
214 			gctl_error(req, "Provider %s already exists.", name);
215 			return (EEXIST);
216 		}
217 	}
218 	gp = g_new_geomf(mp, "%s", name);
219 	sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
220 	sc->sc_offset = offset;
221 	sc->sc_explicitsize = explicitsize;
222 	sc->sc_error = ioerror;
223 	sc->sc_rfailprob = rfailprob;
224 	sc->sc_wfailprob = wfailprob;
225 	sc->sc_reads = 0;
226 	sc->sc_writes = 0;
227 	sc->sc_readbytes = 0;
228 	sc->sc_wrotebytes = 0;
229 	mtx_init(&sc->sc_lock, "gnop lock", NULL, MTX_DEF);
230 	gp->softc = sc;
231 	gp->start = g_nop_start;
232 	gp->orphan = g_nop_orphan;
233 	gp->resize = g_nop_resize;
234 	gp->access = g_nop_access;
235 	gp->dumpconf = g_nop_dumpconf;
236 
237 	newpp = g_new_providerf(gp, "%s", gp->name);
238 	newpp->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE;
239 	newpp->mediasize = size;
240 	newpp->sectorsize = secsize;
241 
242 	cp = g_new_consumer(gp);
243 	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
244 	error = g_attach(cp, pp);
245 	if (error != 0) {
246 		gctl_error(req, "Cannot attach to provider %s.", pp->name);
247 		goto fail;
248 	}
249 
250 	newpp->flags |= pp->flags & G_PF_ACCEPT_UNMAPPED;
251 	g_error_provider(newpp, 0);
252 	G_NOP_DEBUG(0, "Device %s created.", gp->name);
253 	return (0);
254 fail:
255 	if (cp->provider != NULL)
256 		g_detach(cp);
257 	g_destroy_consumer(cp);
258 	g_destroy_provider(newpp);
259 	mtx_destroy(&sc->sc_lock);
260 	g_free(gp->softc);
261 	g_destroy_geom(gp);
262 	return (error);
263 }
264 
265 static int
266 g_nop_destroy(struct g_geom *gp, boolean_t force)
267 {
268 	struct g_nop_softc *sc;
269 	struct g_provider *pp;
270 
271 	g_topology_assert();
272 	sc = gp->softc;
273 	if (sc == NULL)
274 		return (ENXIO);
275 	pp = LIST_FIRST(&gp->provider);
276 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
277 		if (force) {
278 			G_NOP_DEBUG(0, "Device %s is still open, so it "
279 			    "can't be definitely removed.", pp->name);
280 		} else {
281 			G_NOP_DEBUG(1, "Device %s is still open (r%dw%de%d).",
282 			    pp->name, pp->acr, pp->acw, pp->ace);
283 			return (EBUSY);
284 		}
285 	} else {
286 		G_NOP_DEBUG(0, "Device %s removed.", gp->name);
287 	}
288 	gp->softc = NULL;
289 	mtx_destroy(&sc->sc_lock);
290 	g_free(sc);
291 	g_wither_geom(gp, ENXIO);
292 
293 	return (0);
294 }
295 
296 static int
297 g_nop_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp)
298 {
299 
300 	return (g_nop_destroy(gp, 0));
301 }
302 
303 static void
304 g_nop_ctl_create(struct gctl_req *req, struct g_class *mp)
305 {
306 	struct g_provider *pp;
307 	intmax_t *error, *rfailprob, *wfailprob, *offset, *secsize, *size;
308 	const char *name;
309 	char param[16];
310 	int i, *nargs;
311 
312 	g_topology_assert();
313 
314 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
315 	if (nargs == NULL) {
316 		gctl_error(req, "No '%s' argument", "nargs");
317 		return;
318 	}
319 	if (*nargs <= 0) {
320 		gctl_error(req, "Missing device(s).");
321 		return;
322 	}
323 	error = gctl_get_paraml(req, "error", sizeof(*error));
324 	if (error == NULL) {
325 		gctl_error(req, "No '%s' argument", "error");
326 		return;
327 	}
328 	rfailprob = gctl_get_paraml(req, "rfailprob", sizeof(*rfailprob));
329 	if (rfailprob == NULL) {
330 		gctl_error(req, "No '%s' argument", "rfailprob");
331 		return;
332 	}
333 	if (*rfailprob < -1 || *rfailprob > 100) {
334 		gctl_error(req, "Invalid '%s' argument", "rfailprob");
335 		return;
336 	}
337 	wfailprob = gctl_get_paraml(req, "wfailprob", sizeof(*wfailprob));
338 	if (wfailprob == NULL) {
339 		gctl_error(req, "No '%s' argument", "wfailprob");
340 		return;
341 	}
342 	if (*wfailprob < -1 || *wfailprob > 100) {
343 		gctl_error(req, "Invalid '%s' argument", "wfailprob");
344 		return;
345 	}
346 	offset = gctl_get_paraml(req, "offset", sizeof(*offset));
347 	if (offset == NULL) {
348 		gctl_error(req, "No '%s' argument", "offset");
349 		return;
350 	}
351 	if (*offset < 0) {
352 		gctl_error(req, "Invalid '%s' argument", "offset");
353 		return;
354 	}
355 	size = gctl_get_paraml(req, "size", sizeof(*size));
356 	if (size == NULL) {
357 		gctl_error(req, "No '%s' argument", "size");
358 		return;
359 	}
360 	if (*size < 0) {
361 		gctl_error(req, "Invalid '%s' argument", "size");
362 		return;
363 	}
364 	secsize = gctl_get_paraml(req, "secsize", sizeof(*secsize));
365 	if (secsize == NULL) {
366 		gctl_error(req, "No '%s' argument", "secsize");
367 		return;
368 	}
369 	if (*secsize < 0) {
370 		gctl_error(req, "Invalid '%s' argument", "secsize");
371 		return;
372 	}
373 
374 	for (i = 0; i < *nargs; i++) {
375 		snprintf(param, sizeof(param), "arg%d", i);
376 		name = gctl_get_asciiparam(req, param);
377 		if (name == NULL) {
378 			gctl_error(req, "No 'arg%d' argument", i);
379 			return;
380 		}
381 		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
382 			name += strlen("/dev/");
383 		pp = g_provider_by_name(name);
384 		if (pp == NULL) {
385 			G_NOP_DEBUG(1, "Provider %s is invalid.", name);
386 			gctl_error(req, "Provider %s is invalid.", name);
387 			return;
388 		}
389 		if (g_nop_create(req, mp, pp,
390 		    *error == -1 ? EIO : (int)*error,
391 		    *rfailprob == -1 ? 0 : (u_int)*rfailprob,
392 		    *wfailprob == -1 ? 0 : (u_int)*wfailprob,
393 		    (off_t)*offset, (off_t)*size, (u_int)*secsize) != 0) {
394 			return;
395 		}
396 	}
397 }
398 
399 static void
400 g_nop_ctl_configure(struct gctl_req *req, struct g_class *mp)
401 {
402 	struct g_nop_softc *sc;
403 	struct g_provider *pp;
404 	intmax_t *error, *rfailprob, *wfailprob;
405 	const char *name;
406 	char param[16];
407 	int i, *nargs;
408 
409 	g_topology_assert();
410 
411 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
412 	if (nargs == NULL) {
413 		gctl_error(req, "No '%s' argument", "nargs");
414 		return;
415 	}
416 	if (*nargs <= 0) {
417 		gctl_error(req, "Missing device(s).");
418 		return;
419 	}
420 	error = gctl_get_paraml(req, "error", sizeof(*error));
421 	if (error == NULL) {
422 		gctl_error(req, "No '%s' argument", "error");
423 		return;
424 	}
425 	rfailprob = gctl_get_paraml(req, "rfailprob", sizeof(*rfailprob));
426 	if (rfailprob == NULL) {
427 		gctl_error(req, "No '%s' argument", "rfailprob");
428 		return;
429 	}
430 	if (*rfailprob < -1 || *rfailprob > 100) {
431 		gctl_error(req, "Invalid '%s' argument", "rfailprob");
432 		return;
433 	}
434 	wfailprob = gctl_get_paraml(req, "wfailprob", sizeof(*wfailprob));
435 	if (wfailprob == NULL) {
436 		gctl_error(req, "No '%s' argument", "wfailprob");
437 		return;
438 	}
439 	if (*wfailprob < -1 || *wfailprob > 100) {
440 		gctl_error(req, "Invalid '%s' argument", "wfailprob");
441 		return;
442 	}
443 
444 	for (i = 0; i < *nargs; i++) {
445 		snprintf(param, sizeof(param), "arg%d", i);
446 		name = gctl_get_asciiparam(req, param);
447 		if (name == NULL) {
448 			gctl_error(req, "No 'arg%d' argument", i);
449 			return;
450 		}
451 		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
452 			name += strlen("/dev/");
453 		pp = g_provider_by_name(name);
454 		if (pp == NULL || pp->geom->class != mp) {
455 			G_NOP_DEBUG(1, "Provider %s is invalid.", name);
456 			gctl_error(req, "Provider %s is invalid.", name);
457 			return;
458 		}
459 		sc = pp->geom->softc;
460 		if (*error != -1)
461 			sc->sc_error = (int)*error;
462 		if (*rfailprob != -1)
463 			sc->sc_rfailprob = (u_int)*rfailprob;
464 		if (*wfailprob != -1)
465 			sc->sc_wfailprob = (u_int)*wfailprob;
466 	}
467 }
468 
469 static struct g_geom *
470 g_nop_find_geom(struct g_class *mp, const char *name)
471 {
472 	struct g_geom *gp;
473 
474 	LIST_FOREACH(gp, &mp->geom, geom) {
475 		if (strcmp(gp->name, name) == 0)
476 			return (gp);
477 	}
478 	return (NULL);
479 }
480 
481 static void
482 g_nop_ctl_destroy(struct gctl_req *req, struct g_class *mp)
483 {
484 	int *nargs, *force, error, i;
485 	struct g_geom *gp;
486 	const char *name;
487 	char param[16];
488 
489 	g_topology_assert();
490 
491 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
492 	if (nargs == NULL) {
493 		gctl_error(req, "No '%s' argument", "nargs");
494 		return;
495 	}
496 	if (*nargs <= 0) {
497 		gctl_error(req, "Missing device(s).");
498 		return;
499 	}
500 	force = gctl_get_paraml(req, "force", sizeof(*force));
501 	if (force == NULL) {
502 		gctl_error(req, "No 'force' argument");
503 		return;
504 	}
505 
506 	for (i = 0; i < *nargs; i++) {
507 		snprintf(param, sizeof(param), "arg%d", i);
508 		name = gctl_get_asciiparam(req, param);
509 		if (name == NULL) {
510 			gctl_error(req, "No 'arg%d' argument", i);
511 			return;
512 		}
513 		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
514 			name += strlen("/dev/");
515 		gp = g_nop_find_geom(mp, name);
516 		if (gp == NULL) {
517 			G_NOP_DEBUG(1, "Device %s is invalid.", name);
518 			gctl_error(req, "Device %s is invalid.", name);
519 			return;
520 		}
521 		error = g_nop_destroy(gp, *force);
522 		if (error != 0) {
523 			gctl_error(req, "Cannot destroy device %s (error=%d).",
524 			    gp->name, error);
525 			return;
526 		}
527 	}
528 }
529 
530 static void
531 g_nop_ctl_reset(struct gctl_req *req, struct g_class *mp)
532 {
533 	struct g_nop_softc *sc;
534 	struct g_provider *pp;
535 	const char *name;
536 	char param[16];
537 	int i, *nargs;
538 
539 	g_topology_assert();
540 
541 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
542 	if (nargs == NULL) {
543 		gctl_error(req, "No '%s' argument", "nargs");
544 		return;
545 	}
546 	if (*nargs <= 0) {
547 		gctl_error(req, "Missing device(s).");
548 		return;
549 	}
550 
551 	for (i = 0; i < *nargs; i++) {
552 		snprintf(param, sizeof(param), "arg%d", i);
553 		name = gctl_get_asciiparam(req, param);
554 		if (name == NULL) {
555 			gctl_error(req, "No 'arg%d' argument", i);
556 			return;
557 		}
558 		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
559 			name += strlen("/dev/");
560 		pp = g_provider_by_name(name);
561 		if (pp == NULL || pp->geom->class != mp) {
562 			G_NOP_DEBUG(1, "Provider %s is invalid.", name);
563 			gctl_error(req, "Provider %s is invalid.", name);
564 			return;
565 		}
566 		sc = pp->geom->softc;
567 		sc->sc_reads = 0;
568 		sc->sc_writes = 0;
569 		sc->sc_readbytes = 0;
570 		sc->sc_wrotebytes = 0;
571 	}
572 }
573 
574 static void
575 g_nop_config(struct gctl_req *req, struct g_class *mp, const char *verb)
576 {
577 	uint32_t *version;
578 
579 	g_topology_assert();
580 
581 	version = gctl_get_paraml(req, "version", sizeof(*version));
582 	if (version == NULL) {
583 		gctl_error(req, "No '%s' argument.", "version");
584 		return;
585 	}
586 	if (*version != G_NOP_VERSION) {
587 		gctl_error(req, "Userland and kernel parts are out of sync.");
588 		return;
589 	}
590 
591 	if (strcmp(verb, "create") == 0) {
592 		g_nop_ctl_create(req, mp);
593 		return;
594 	} else if (strcmp(verb, "configure") == 0) {
595 		g_nop_ctl_configure(req, mp);
596 		return;
597 	} else if (strcmp(verb, "destroy") == 0) {
598 		g_nop_ctl_destroy(req, mp);
599 		return;
600 	} else if (strcmp(verb, "reset") == 0) {
601 		g_nop_ctl_reset(req, mp);
602 		return;
603 	}
604 
605 	gctl_error(req, "Unknown verb.");
606 }
607 
608 static void
609 g_nop_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
610     struct g_consumer *cp, struct g_provider *pp)
611 {
612 	struct g_nop_softc *sc;
613 
614 	if (pp != NULL || cp != NULL)
615 		return;
616 	sc = gp->softc;
617 	sbuf_printf(sb, "%s<Offset>%jd</Offset>\n", indent,
618 	    (intmax_t)sc->sc_offset);
619 	sbuf_printf(sb, "%s<ReadFailProb>%u</ReadFailProb>\n", indent,
620 	    sc->sc_rfailprob);
621 	sbuf_printf(sb, "%s<WriteFailProb>%u</WriteFailProb>\n", indent,
622 	    sc->sc_wfailprob);
623 	sbuf_printf(sb, "%s<Error>%d</Error>\n", indent, sc->sc_error);
624 	sbuf_printf(sb, "%s<Reads>%ju</Reads>\n", indent, sc->sc_reads);
625 	sbuf_printf(sb, "%s<Writes>%ju</Writes>\n", indent, sc->sc_writes);
626 	sbuf_printf(sb, "%s<ReadBytes>%ju</ReadBytes>\n", indent,
627 	    sc->sc_readbytes);
628 	sbuf_printf(sb, "%s<WroteBytes>%ju</WroteBytes>\n", indent,
629 	    sc->sc_wrotebytes);
630 }
631 
632 DECLARE_GEOM_CLASS(g_nop_class, g_nop);
633