FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_subr.c
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: releng/5.4/sys/geom/geom_subr.c 145335 2005-04-20 19:11:07Z cvs2svn $");
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/devicestat.h>
42 #include <sys/kernel.h>
43 #include <sys/malloc.h>
44 #include <sys/bio.h>
45 #include <sys/sysctl.h>
46 #include <sys/proc.h>
47 #include <sys/kthread.h>
48 #include <sys/lock.h>
49 #include <sys/mutex.h>
50 #include <sys/errno.h>
51 #include <sys/sbuf.h>
52 #include <geom/geom.h>
53 #include <geom/geom_int.h>
54 #include <machine/stdarg.h>
55
56 struct class_list_head g_classes = LIST_HEAD_INITIALIZER(g_classes);
57 static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms);
58 char *g_wait_event, *g_wait_up, *g_wait_down, *g_wait_sim;
59
60 struct g_hh00 {
61 struct g_class *mp;
62 int error;
63 };
64
65 /*
66 * This event offers a new class a chance to taste all preexisting providers.
67 */
68 static void
69 g_load_class(void *arg, int flag)
70 {
71 struct g_hh00 *hh;
72 struct g_class *mp2, *mp;
73 struct g_geom *gp;
74 struct g_provider *pp;
75
76 g_topology_assert();
77 if (flag == EV_CANCEL) /* XXX: can't happen ? */
78 return;
79 if (g_shutdown)
80 return;
81
82 hh = arg;
83 mp = hh->mp;
84 g_free(hh);
85 g_trace(G_T_TOPOLOGY, "g_load_class(%s)", mp->name);
86 KASSERT(mp->name != NULL && *mp->name != '\0',
87 ("GEOM class has no name"));
88 LIST_FOREACH(mp2, &g_classes, class) {
89 KASSERT(mp2 != mp,
90 ("The GEOM class %s already loaded", mp2->name));
91 KASSERT(strcmp(mp2->name, mp->name) != 0,
92 ("A GEOM class named %s is already loaded", mp2->name));
93 }
94
95 LIST_INIT(&mp->geom);
96 LIST_INSERT_HEAD(&g_classes, mp, class);
97 if (mp->init != NULL)
98 mp->init(mp);
99 if (mp->taste == NULL)
100 return;
101 LIST_FOREACH(mp2, &g_classes, class) {
102 if (mp == mp2)
103 continue;
104 LIST_FOREACH(gp, &mp2->geom, geom) {
105 LIST_FOREACH(pp, &gp->provider, provider) {
106 mp->taste(mp, pp, 0);
107 g_topology_assert();
108 }
109 }
110 }
111 }
112
113 static void
114 g_unload_class(void *arg, int flag)
115 {
116 struct g_hh00 *hh;
117 struct g_class *mp;
118 struct g_geom *gp;
119 struct g_provider *pp;
120 struct g_consumer *cp;
121 int error;
122
123 g_topology_assert();
124 hh = arg;
125 mp = hh->mp;
126 G_VALID_CLASS(mp);
127 g_trace(G_T_TOPOLOGY, "g_unload_class(%s)", mp->name);
128
129 /*
130 * We allow unloading if we have no geoms, or a class
131 * method we can use to get rid of them.
132 */
133 if (!LIST_EMPTY(&mp->geom) && mp->destroy_geom == NULL) {
134 hh->error = EOPNOTSUPP;
135 return;
136 }
137
138 /* We refuse to unload if anything is open */
139 LIST_FOREACH(gp, &mp->geom, geom) {
140 LIST_FOREACH(pp, &gp->provider, provider)
141 if (pp->acr || pp->acw || pp->ace) {
142 hh->error = EBUSY;
143 return;
144 }
145 LIST_FOREACH(cp, &gp->consumer, consumer)
146 if (cp->acr || cp->acw || cp->ace) {
147 hh->error = EBUSY;
148 return;
149 }
150 }
151
152 /* Bar new entries */
153 mp->taste = NULL;
154 mp->config = NULL;
155
156 error = 0;
157 for (;;) {
158 gp = LIST_FIRST(&mp->geom);
159 if (gp == NULL)
160 break;
161 error = mp->destroy_geom(NULL, mp, gp);
162 if (error != 0)
163 break;
164 }
165 if (error == 0) {
166 if (mp->fini != NULL)
167 mp->fini(mp);
168 LIST_REMOVE(mp, class);
169 }
170 hh->error = error;
171 return;
172 }
173
174 int
175 g_modevent(module_t mod, int type, void *data)
176 {
177 struct g_hh00 *hh;
178 int error;
179 static int g_ignition;
180 struct g_class *mp;
181
182 mp = data;
183 if (mp->version != G_VERSION) {
184 printf("GEOM class %s has Wrong version %x\n",
185 mp->name, mp->version);
186 return (EINVAL);
187 }
188 if (!g_ignition) {
189 g_ignition++;
190 g_init();
191 }
192 hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
193 hh->mp = data;
194 error = EOPNOTSUPP;
195 switch (type) {
196 case MOD_LOAD:
197 g_trace(G_T_TOPOLOGY, "g_modevent(%s, LOAD)", hh->mp->name);
198 g_post_event(g_load_class, hh, M_WAITOK, NULL);
199 error = 0;
200 break;
201 case MOD_UNLOAD:
202 g_trace(G_T_TOPOLOGY, "g_modevent(%s, UNLOAD)", hh->mp->name);
203 error = g_waitfor_event(g_unload_class, hh, M_WAITOK, NULL);
204 if (error == 0)
205 error = hh->error;
206 if (error == 0) {
207 KASSERT(LIST_EMPTY(&hh->mp->geom),
208 ("Unloaded class (%s) still has geom", hh->mp->name));
209 }
210 g_free(hh);
211 break;
212 default:
213 g_free(hh);
214 break;
215 }
216 return (error);
217 }
218
219 struct g_geom *
220 g_new_geomf(struct g_class *mp, const char *fmt, ...)
221 {
222 struct g_geom *gp;
223 va_list ap;
224 struct sbuf *sb;
225
226 g_topology_assert();
227 G_VALID_CLASS(mp);
228 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
229 va_start(ap, fmt);
230 sbuf_vprintf(sb, fmt, ap);
231 va_end(ap);
232 sbuf_finish(sb);
233 gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO);
234 gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
235 gp->class = mp;
236 gp->rank = 1;
237 LIST_INIT(&gp->consumer);
238 LIST_INIT(&gp->provider);
239 LIST_INSERT_HEAD(&mp->geom, gp, geom);
240 TAILQ_INSERT_HEAD(&geoms, gp, geoms);
241 strcpy(gp->name, sbuf_data(sb));
242 sbuf_delete(sb);
243 /* Fill in defaults from class */
244 gp->start = mp->start;
245 gp->spoiled = mp->spoiled;
246 gp->dumpconf = mp->dumpconf;
247 gp->access = mp->access;
248 gp->orphan = mp->orphan;
249 gp->ioctl = mp->ioctl;
250 return (gp);
251 }
252
253 void
254 g_destroy_geom(struct g_geom *gp)
255 {
256
257 g_topology_assert();
258 G_VALID_GEOM(gp);
259 g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
260 KASSERT(LIST_EMPTY(&gp->consumer),
261 ("g_destroy_geom(%s) with consumer(s) [%p]",
262 gp->name, LIST_FIRST(&gp->consumer)));
263 KASSERT(LIST_EMPTY(&gp->provider),
264 ("g_destroy_geom(%s) with provider(s) [%p]",
265 gp->name, LIST_FIRST(&gp->provider)));
266 g_cancel_event(gp);
267 LIST_REMOVE(gp, geom);
268 TAILQ_REMOVE(&geoms, gp, geoms);
269 g_free(gp->name);
270 g_free(gp);
271 }
272
273 /*
274 * This function is called (repeatedly) until the has withered away.
275 */
276 void
277 g_wither_geom(struct g_geom *gp, int error)
278 {
279 struct g_provider *pp;
280
281 g_topology_assert();
282 G_VALID_GEOM(gp);
283 g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name);
284 if (!(gp->flags & G_GEOM_WITHER)) {
285 gp->flags |= G_GEOM_WITHER;
286 LIST_FOREACH(pp, &gp->provider, provider)
287 if (!(pp->flags & G_PF_ORPHAN))
288 g_orphan_provider(pp, error);
289 }
290 g_do_wither();
291 }
292
293 /*
294 * This function is called (repeatedly) until we cant wash away more
295 * withered bits at present. Return value contains two bits. Bit 0
296 * set means "withering stuff we can't wash now", bit 1 means "call
297 * me again, there may be stuff I didn't get the first time around.
298 */
299 int
300 g_wither_washer()
301 {
302 struct g_class *mp;
303 struct g_geom *gp, *gp2;
304 struct g_provider *pp, *pp2;
305 struct g_consumer *cp, *cp2;
306 int result;
307
308 result = 0;
309 g_topology_assert();
310 LIST_FOREACH(mp, &g_classes, class) {
311 LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
312 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
313 if (!(pp->flags & G_PF_WITHER))
314 continue;
315 if (LIST_EMPTY(&pp->consumers))
316 g_destroy_provider(pp);
317 else
318 result |= 1;
319 }
320 if (!(gp->flags & G_GEOM_WITHER))
321 continue;
322 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
323 if (LIST_EMPTY(&pp->consumers))
324 g_destroy_provider(pp);
325 else
326 result |= 1;
327 }
328 LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp2) {
329 if (cp->acr || cp->acw || cp->ace) {
330 result |= 1;
331 continue;
332 }
333 if (cp->provider != NULL)
334 g_detach(cp);
335 g_destroy_consumer(cp);
336 result |= 2;
337 }
338 if (LIST_EMPTY(&gp->provider) &&
339 LIST_EMPTY(&gp->consumer))
340 g_destroy_geom(gp);
341 else
342 result |= 1;
343 }
344 }
345 return (result);
346 }
347
348 struct g_consumer *
349 g_new_consumer(struct g_geom *gp)
350 {
351 struct g_consumer *cp;
352
353 g_topology_assert();
354 G_VALID_GEOM(gp);
355 KASSERT(!(gp->flags & G_GEOM_WITHER),
356 ("g_new_consumer on WITHERing geom(%s) (class %s)",
357 gp->name, gp->class->name));
358 KASSERT(gp->orphan != NULL,
359 ("g_new_consumer on geom(%s) (class %s) without orphan",
360 gp->name, gp->class->name));
361
362 cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO);
363 cp->geom = gp;
364 cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED,
365 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
366 LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
367 return(cp);
368 }
369
370 void
371 g_destroy_consumer(struct g_consumer *cp)
372 {
373 struct g_geom *gp;
374
375 g_topology_assert();
376 G_VALID_CONSUMER(cp);
377 g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
378 KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
379 KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
380 KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
381 KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
382 g_cancel_event(cp);
383 gp = cp->geom;
384 LIST_REMOVE(cp, consumer);
385 devstat_remove_entry(cp->stat);
386 g_free(cp);
387 if (gp->flags & G_GEOM_WITHER)
388 g_do_wither();
389 }
390
391 static void
392 g_new_provider_event(void *arg, int flag)
393 {
394 struct g_class *mp;
395 struct g_provider *pp;
396 struct g_consumer *cp;
397 int i;
398
399 g_topology_assert();
400 if (flag == EV_CANCEL)
401 return;
402 if (g_shutdown)
403 return;
404 pp = arg;
405 G_VALID_PROVIDER(pp);
406 LIST_FOREACH(mp, &g_classes, class) {
407 if (mp->taste == NULL)
408 continue;
409 i = 1;
410 LIST_FOREACH(cp, &pp->consumers, consumers)
411 if (cp->geom->class == mp)
412 i = 0;
413 if (!i)
414 continue;
415 mp->taste(mp, pp, 0);
416 g_topology_assert();
417 }
418 }
419
420
421 struct g_provider *
422 g_new_providerf(struct g_geom *gp, const char *fmt, ...)
423 {
424 struct g_provider *pp;
425 struct sbuf *sb;
426 va_list ap;
427
428 g_topology_assert();
429 G_VALID_GEOM(gp);
430 KASSERT(gp->access != NULL,
431 ("new provider on geom(%s) without ->access (class %s)",
432 gp->name, gp->class->name));
433 KASSERT(gp->start != NULL,
434 ("new provider on geom(%s) without ->start (class %s)",
435 gp->name, gp->class->name));
436 KASSERT(!(gp->flags & G_GEOM_WITHER),
437 ("new provider on WITHERing geom(%s) (class %s)",
438 gp->name, gp->class->name));
439 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
440 va_start(ap, fmt);
441 sbuf_vprintf(sb, fmt, ap);
442 va_end(ap);
443 sbuf_finish(sb);
444 pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
445 pp->name = (char *)(pp + 1);
446 strcpy(pp->name, sbuf_data(sb));
447 sbuf_delete(sb);
448 LIST_INIT(&pp->consumers);
449 pp->error = ENXIO;
450 pp->geom = gp;
451 pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED,
452 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
453 LIST_INSERT_HEAD(&gp->provider, pp, provider);
454 g_post_event(g_new_provider_event, pp, M_WAITOK, pp, gp, NULL);
455 return (pp);
456 }
457
458 void
459 g_error_provider(struct g_provider *pp, int error)
460 {
461
462 /* G_VALID_PROVIDER(pp); We may not have g_topology */
463 pp->error = error;
464 }
465
466 struct g_provider *
467 g_provider_by_name(char const *arg)
468 {
469 struct g_class *cp;
470 struct g_geom *gp;
471 struct g_provider *pp;
472
473 LIST_FOREACH(cp, &g_classes, class) {
474 LIST_FOREACH(gp, &cp->geom, geom) {
475 LIST_FOREACH(pp, &gp->provider, provider) {
476 if (!strcmp(arg, pp->name))
477 return (pp);
478 }
479 }
480 }
481 return (NULL);
482 }
483
484 void
485 g_destroy_provider(struct g_provider *pp)
486 {
487 struct g_geom *gp;
488
489 g_topology_assert();
490 G_VALID_PROVIDER(pp);
491 KASSERT(LIST_EMPTY(&pp->consumers),
492 ("g_destroy_provider but attached"));
493 KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
494 KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
495 KASSERT (pp->acw == 0, ("g_destroy_provider with ace"));
496 g_cancel_event(pp);
497 LIST_REMOVE(pp, provider);
498 gp = pp->geom;
499 devstat_remove_entry(pp->stat);
500 g_free(pp);
501 if ((gp->flags & G_GEOM_WITHER))
502 g_do_wither();
503 }
504
505 /*
506 * We keep the "geoms" list sorted by topological order (== increasing
507 * numerical rank) at all times.
508 * When an attach is done, the attaching geoms rank is invalidated
509 * and it is moved to the tail of the list.
510 * All geoms later in the sequence has their ranks reevaluated in
511 * sequence. If we cannot assign rank to a geom because it's
512 * prerequisites do not have rank, we move that element to the tail
513 * of the sequence with invalid rank as well.
514 * At some point we encounter our original geom and if we stil fail
515 * to assign it a rank, there must be a loop and we fail back to
516 * g_attach() which detach again and calls redo_rank again
517 * to fix up the damage.
518 * It would be much simpler code wise to do it recursively, but we
519 * can't risk that on the kernel stack.
520 */
521
522 static int
523 redo_rank(struct g_geom *gp)
524 {
525 struct g_consumer *cp;
526 struct g_geom *gp1, *gp2;
527 int n, m;
528
529 g_topology_assert();
530 G_VALID_GEOM(gp);
531
532 /* Invalidate this geoms rank and move it to the tail */
533 gp1 = TAILQ_NEXT(gp, geoms);
534 if (gp1 != NULL) {
535 gp->rank = 0;
536 TAILQ_REMOVE(&geoms, gp, geoms);
537 TAILQ_INSERT_TAIL(&geoms, gp, geoms);
538 } else {
539 gp1 = gp;
540 }
541
542 /* re-rank the rest of the sequence */
543 for (; gp1 != NULL; gp1 = gp2) {
544 gp1->rank = 0;
545 m = 1;
546 LIST_FOREACH(cp, &gp1->consumer, consumer) {
547 if (cp->provider == NULL)
548 continue;
549 n = cp->provider->geom->rank;
550 if (n == 0) {
551 m = 0;
552 break;
553 } else if (n >= m)
554 m = n + 1;
555 }
556 gp1->rank = m;
557 gp2 = TAILQ_NEXT(gp1, geoms);
558
559 /* got a rank, moving on */
560 if (m != 0)
561 continue;
562
563 /* no rank to original geom means loop */
564 if (gp == gp1)
565 return (ELOOP);
566
567 /* no rank, put it at the end move on */
568 TAILQ_REMOVE(&geoms, gp1, geoms);
569 TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
570 }
571 return (0);
572 }
573
574 int
575 g_attach(struct g_consumer *cp, struct g_provider *pp)
576 {
577 int error;
578
579 g_topology_assert();
580 G_VALID_CONSUMER(cp);
581 G_VALID_PROVIDER(pp);
582 KASSERT(cp->provider == NULL, ("attach but attached"));
583 cp->provider = pp;
584 LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
585 error = redo_rank(cp->geom);
586 if (error) {
587 LIST_REMOVE(cp, consumers);
588 cp->provider = NULL;
589 redo_rank(cp->geom);
590 }
591 return (error);
592 }
593
594 void
595 g_detach(struct g_consumer *cp)
596 {
597 struct g_provider *pp;
598
599 g_topology_assert();
600 G_VALID_CONSUMER(cp);
601 g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp);
602 KASSERT(cp->provider != NULL, ("detach but not attached"));
603 KASSERT(cp->acr == 0, ("detach but nonzero acr"));
604 KASSERT(cp->acw == 0, ("detach but nonzero acw"));
605 KASSERT(cp->ace == 0, ("detach but nonzero ace"));
606 KASSERT(cp->nstart == cp->nend,
607 ("detach with active requests"));
608 pp = cp->provider;
609 LIST_REMOVE(cp, consumers);
610 cp->provider = NULL;
611 if (pp->geom->flags & G_GEOM_WITHER)
612 g_do_wither();
613 else if (pp->flags & G_PF_WITHER)
614 g_do_wither();
615 redo_rank(cp->geom);
616 }
617
618 /*
619 * g_access()
620 *
621 * Access-check with delta values. The question asked is "can provider
622 * "cp" change the access counters by the relative amounts dc[rwe] ?"
623 */
624
625 int
626 g_access(struct g_consumer *cp, int dcr, int dcw, int dce)
627 {
628 struct g_provider *pp;
629 int pr,pw,pe;
630 int error;
631
632 g_topology_assert();
633 G_VALID_CONSUMER(cp);
634 pp = cp->provider;
635 KASSERT(pp != NULL, ("access but not attached"));
636 G_VALID_PROVIDER(pp);
637
638 g_trace(G_T_ACCESS, "g_access(%p(%s), %d, %d, %d)",
639 cp, pp->name, dcr, dcw, dce);
640
641 KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
642 KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
643 KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
644 KASSERT(dcr != 0 || dcw != 0 || dce != 0, ("NOP access request"));
645 KASSERT(pp->geom->access != NULL, ("NULL geom->access"));
646
647 /*
648 * If our class cares about being spoiled, and we have been, we
649 * are probably just ahead of the event telling us that. Fail
650 * now rather than having to unravel this later.
651 */
652 if (cp->geom->spoiled != NULL && cp->spoiled &&
653 (dcr > 0 || dcw > 0 || dce > 0))
654 return (ENXIO);
655
656 /*
657 * Figure out what counts the provider would have had, if this
658 * consumer had (r0w0e0) at this time.
659 */
660 pr = pp->acr - cp->acr;
661 pw = pp->acw - cp->acw;
662 pe = pp->ace - cp->ace;
663
664 g_trace(G_T_ACCESS,
665 "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
666 dcr, dcw, dce,
667 cp->acr, cp->acw, cp->ace,
668 pp->acr, pp->acw, pp->ace,
669 pp, pp->name);
670
671 /* If foot-shooting is enabled, any open on rank#1 is OK */
672 if ((g_debugflags & 16) && pp->geom->rank == 1)
673 ;
674 /* If we try exclusive but already write: fail */
675 else if (dce > 0 && pw > 0)
676 return (EPERM);
677 /* If we try write but already exclusive: fail */
678 else if (dcw > 0 && pe > 0)
679 return (EPERM);
680 /* If we try to open more but provider is error'ed: fail */
681 else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0)
682 return (pp->error);
683
684 /* Ok then... */
685
686 error = pp->geom->access(pp, dcr, dcw, dce);
687 KASSERT(dcr > 0 || dcw > 0 || dce > 0 || error == 0,
688 ("Geom provider %s::%s failed closing ->access()",
689 pp->geom->class->name, pp->name));
690 if (!error) {
691 /*
692 * If we open first write, spoil any partner consumers.
693 * If we close last write, trigger re-taste.
694 */
695 if (pp->acw == 0 && dcw != 0)
696 g_spoil(pp, cp);
697 else if (pp->acw != 0 && pp->acw == -dcw &&
698 !(pp->geom->flags & G_GEOM_WITHER))
699 g_post_event(g_new_provider_event, pp, M_WAITOK,
700 pp, NULL);
701
702 pp->acr += dcr;
703 pp->acw += dcw;
704 pp->ace += dce;
705 cp->acr += dcr;
706 cp->acw += dcw;
707 cp->ace += dce;
708 if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)
709 KASSERT(pp->sectorsize > 0,
710 ("Provider %s lacks sectorsize", pp->name));
711 }
712 return (error);
713 }
714
715 int
716 g_handleattr_int(struct bio *bp, const char *attribute, int val)
717 {
718
719 return (g_handleattr(bp, attribute, &val, sizeof val));
720 }
721
722 int
723 g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val)
724 {
725
726 return (g_handleattr(bp, attribute, &val, sizeof val));
727 }
728
729 int
730 g_handleattr(struct bio *bp, const char *attribute, void *val, int len)
731 {
732 int error;
733
734 if (strcmp(bp->bio_attribute, attribute))
735 return (0);
736 if (bp->bio_length != len) {
737 printf("bio_length %jd len %d -> EFAULT\n",
738 (intmax_t)bp->bio_length, len);
739 error = EFAULT;
740 } else {
741 error = 0;
742 bcopy(val, bp->bio_data, len);
743 bp->bio_completed = len;
744 }
745 g_io_deliver(bp, error);
746 return (1);
747 }
748
749 int
750 g_std_access(struct g_provider *pp,
751 int dr __unused, int dw __unused, int de __unused)
752 {
753
754 g_topology_assert();
755 G_VALID_PROVIDER(pp);
756 return (0);
757 }
758
759 void
760 g_std_done(struct bio *bp)
761 {
762 struct bio *bp2;
763
764 bp2 = bp->bio_parent;
765 if (bp2->bio_error == 0)
766 bp2->bio_error = bp->bio_error;
767 bp2->bio_completed += bp->bio_completed;
768 g_destroy_bio(bp);
769 bp2->bio_inbed++;
770 if (bp2->bio_children == bp2->bio_inbed)
771 g_io_deliver(bp2, bp2->bio_error);
772 }
773
774 /* XXX: maybe this is only g_slice_spoiled */
775
776 void
777 g_std_spoiled(struct g_consumer *cp)
778 {
779 struct g_geom *gp;
780 struct g_provider *pp;
781
782 g_topology_assert();
783 G_VALID_CONSUMER(cp);
784 g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
785 g_detach(cp);
786 gp = cp->geom;
787 LIST_FOREACH(pp, &gp->provider, provider)
788 g_orphan_provider(pp, ENXIO);
789 g_destroy_consumer(cp);
790 if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
791 g_destroy_geom(gp);
792 else
793 gp->flags |= G_GEOM_WITHER;
794 }
795
796 /*
797 * Spoiling happens when a provider is opened for writing, but consumers
798 * which are configured by in-band data are attached (slicers for instance).
799 * Since the write might potentially change the in-band data, such consumers
800 * need to re-evaluate their existence after the writing session closes.
801 * We do this by (offering to) tear them down when the open for write happens
802 * in return for a re-taste when it closes again.
803 * Together with the fact that such consumers grab an 'e' bit whenever they
804 * are open, regardless of mode, this ends up DTRT.
805 */
806
807 static void
808 g_spoil_event(void *arg, int flag)
809 {
810 struct g_provider *pp;
811 struct g_consumer *cp, *cp2;
812
813 g_topology_assert();
814 if (flag == EV_CANCEL)
815 return;
816 pp = arg;
817 G_VALID_PROVIDER(pp);
818 for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) {
819 cp2 = LIST_NEXT(cp, consumers);
820 if (!cp->spoiled)
821 continue;
822 cp->spoiled = 0;
823 if (cp->geom->spoiled == NULL)
824 continue;
825 cp->geom->spoiled(cp);
826 g_topology_assert();
827 }
828 }
829
830 void
831 g_spoil(struct g_provider *pp, struct g_consumer *cp)
832 {
833 struct g_consumer *cp2;
834
835 g_topology_assert();
836 G_VALID_PROVIDER(pp);
837 G_VALID_CONSUMER(cp);
838
839 LIST_FOREACH(cp2, &pp->consumers, consumers) {
840 if (cp2 == cp)
841 continue;
842 /*
843 KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
844 KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
845 */
846 KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
847 cp2->spoiled++;
848 }
849 g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL);
850 }
851
852 int
853 g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len)
854 {
855 int error, i;
856
857 i = len;
858 error = g_io_getattr(attr, cp, &i, var);
859 if (error)
860 return (error);
861 if (i != len)
862 return (EINVAL);
863 return (0);
864 }
865
866 #ifdef DIAGNOSTIC
867 /*
868 * This function walks (topologically unsafely) the mesh and return a
869 * non-zero integer if it finds the argument pointer is an object.
870 * The return value indicates which type of object it is belived to be.
871 * If topology is not locked, this function is potentially dangerous,
872 * but since it is for debugging purposes and can be useful for instance
873 * from DDB, we do not assert topology lock is held.
874 */
875 int
876 g_valid_obj(void const *ptr)
877 {
878 struct g_class *mp;
879 struct g_geom *gp;
880 struct g_consumer *cp;
881 struct g_provider *pp;
882
883 LIST_FOREACH(mp, &g_classes, class) {
884 if (ptr == mp)
885 return (1);
886 LIST_FOREACH(gp, &mp->geom, geom) {
887 if (ptr == gp)
888 return (2);
889 LIST_FOREACH(cp, &gp->consumer, consumer)
890 if (ptr == cp)
891 return (3);
892 LIST_FOREACH(pp, &gp->provider, provider)
893 if (ptr == pp)
894 return (4);
895 }
896 }
897 return(0);
898 }
899 #endif
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