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/5.3/sys/geom/geom_subr.c 136588 2004-10-16 08:43:07Z 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 g_waitidle();
208 KASSERT(LIST_EMPTY(&hh->mp->geom),
209 ("Unloaded class (%s) still has geom", hh->mp->name));
210 }
211 g_free(hh);
212 break;
213 default:
214 g_free(hh);
215 break;
216 }
217 return (error);
218 }
219
220 struct g_geom *
221 g_new_geomf(struct g_class *mp, const char *fmt, ...)
222 {
223 struct g_geom *gp;
224 va_list ap;
225 struct sbuf *sb;
226
227 g_topology_assert();
228 G_VALID_CLASS(mp);
229 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
230 va_start(ap, fmt);
231 sbuf_vprintf(sb, fmt, ap);
232 va_end(ap);
233 sbuf_finish(sb);
234 gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO);
235 gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
236 gp->class = mp;
237 gp->rank = 1;
238 LIST_INIT(&gp->consumer);
239 LIST_INIT(&gp->provider);
240 LIST_INSERT_HEAD(&mp->geom, gp, geom);
241 TAILQ_INSERT_HEAD(&geoms, gp, geoms);
242 strcpy(gp->name, sbuf_data(sb));
243 sbuf_delete(sb);
244 /* Fill in defaults from class */
245 gp->start = mp->start;
246 gp->spoiled = mp->spoiled;
247 gp->dumpconf = mp->dumpconf;
248 gp->access = mp->access;
249 gp->orphan = mp->orphan;
250 gp->ioctl = mp->ioctl;
251 return (gp);
252 }
253
254 void
255 g_destroy_geom(struct g_geom *gp)
256 {
257
258 g_topology_assert();
259 G_VALID_GEOM(gp);
260 g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
261 KASSERT(LIST_EMPTY(&gp->consumer),
262 ("g_destroy_geom(%s) with consumer(s) [%p]",
263 gp->name, LIST_FIRST(&gp->consumer)));
264 KASSERT(LIST_EMPTY(&gp->provider),
265 ("g_destroy_geom(%s) with provider(s) [%p]",
266 gp->name, LIST_FIRST(&gp->provider)));
267 g_cancel_event(gp);
268 LIST_REMOVE(gp, geom);
269 TAILQ_REMOVE(&geoms, gp, geoms);
270 g_free(gp->name);
271 g_free(gp);
272 }
273
274 /*
275 * This function is called (repeatedly) until the has withered away.
276 */
277 void
278 g_wither_geom(struct g_geom *gp, int error)
279 {
280 struct g_provider *pp;
281
282 g_topology_assert();
283 G_VALID_GEOM(gp);
284 g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name);
285 if (!(gp->flags & G_GEOM_WITHER)) {
286 gp->flags |= G_GEOM_WITHER;
287 LIST_FOREACH(pp, &gp->provider, provider)
288 if (!(pp->flags & G_PF_ORPHAN))
289 g_orphan_provider(pp, error);
290 }
291 g_do_wither();
292 }
293
294 /*
295 * This function is called (repeatedly) until we cant wash away more
296 * withered bits at present. Return value contains two bits. Bit 0
297 * set means "withering stuff we can't wash now", bit 1 means "call
298 * me again, there may be stuff I didn't get the first time around.
299 */
300 int
301 g_wither_washer()
302 {
303 struct g_class *mp;
304 struct g_geom *gp, *gp2;
305 struct g_provider *pp, *pp2;
306 struct g_consumer *cp, *cp2;
307 int result;
308
309 result = 0;
310 g_topology_assert();
311 LIST_FOREACH(mp, &g_classes, class) {
312 LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
313 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
314 if (!(pp->flags & G_PF_WITHER))
315 continue;
316 if (LIST_EMPTY(&pp->consumers))
317 g_destroy_provider(pp);
318 else
319 result |= 1;
320 }
321 if (!(gp->flags & G_GEOM_WITHER))
322 continue;
323 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
324 if (LIST_EMPTY(&pp->consumers))
325 g_destroy_provider(pp);
326 else
327 result |= 1;
328 }
329 LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp2) {
330 if (cp->acr || cp->acw || cp->ace) {
331 result |= 1;
332 continue;
333 }
334 if (cp->provider != NULL)
335 g_detach(cp);
336 g_destroy_consumer(cp);
337 result |= 2;
338 }
339 if (LIST_EMPTY(&gp->provider) &&
340 LIST_EMPTY(&gp->consumer))
341 g_destroy_geom(gp);
342 else
343 result |= 1;
344 }
345 }
346 return (result);
347 }
348
349 struct g_consumer *
350 g_new_consumer(struct g_geom *gp)
351 {
352 struct g_consumer *cp;
353
354 g_topology_assert();
355 G_VALID_GEOM(gp);
356 KASSERT(!(gp->flags & G_GEOM_WITHER),
357 ("g_new_consumer on WITHERing geom(%s) (class %s)",
358 gp->name, gp->class->name));
359 KASSERT(gp->orphan != NULL,
360 ("g_new_consumer on geom(%s) (class %s) without orphan",
361 gp->name, gp->class->name));
362
363 cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO);
364 cp->geom = gp;
365 cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED,
366 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
367 LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
368 return(cp);
369 }
370
371 void
372 g_destroy_consumer(struct g_consumer *cp)
373 {
374 struct g_geom *gp;
375
376 g_topology_assert();
377 G_VALID_CONSUMER(cp);
378 g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
379 KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
380 KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
381 KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
382 KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
383 g_cancel_event(cp);
384 gp = cp->geom;
385 LIST_REMOVE(cp, consumer);
386 devstat_remove_entry(cp->stat);
387 g_free(cp);
388 if (gp->flags & G_GEOM_WITHER)
389 g_do_wither();
390 }
391
392 static void
393 g_new_provider_event(void *arg, int flag)
394 {
395 struct g_class *mp;
396 struct g_provider *pp;
397 struct g_consumer *cp;
398 int i;
399
400 g_topology_assert();
401 if (flag == EV_CANCEL)
402 return;
403 if (g_shutdown)
404 return;
405 pp = arg;
406 G_VALID_PROVIDER(pp);
407 LIST_FOREACH(mp, &g_classes, class) {
408 if (mp->taste == NULL)
409 continue;
410 i = 1;
411 LIST_FOREACH(cp, &pp->consumers, consumers)
412 if (cp->geom->class == mp)
413 i = 0;
414 if (!i)
415 continue;
416 mp->taste(mp, pp, 0);
417 g_topology_assert();
418 }
419 }
420
421
422 struct g_provider *
423 g_new_providerf(struct g_geom *gp, const char *fmt, ...)
424 {
425 struct g_provider *pp;
426 struct sbuf *sb;
427 va_list ap;
428
429 g_topology_assert();
430 G_VALID_GEOM(gp);
431 KASSERT(gp->access != NULL,
432 ("new provider on geom(%s) without ->access (class %s)",
433 gp->name, gp->class->name));
434 KASSERT(gp->start != NULL,
435 ("new provider on geom(%s) without ->start (class %s)",
436 gp->name, gp->class->name));
437 KASSERT(!(gp->flags & G_GEOM_WITHER),
438 ("new provider on WITHERing geom(%s) (class %s)",
439 gp->name, gp->class->name));
440 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
441 va_start(ap, fmt);
442 sbuf_vprintf(sb, fmt, ap);
443 va_end(ap);
444 sbuf_finish(sb);
445 pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
446 pp->name = (char *)(pp + 1);
447 strcpy(pp->name, sbuf_data(sb));
448 sbuf_delete(sb);
449 LIST_INIT(&pp->consumers);
450 pp->error = ENXIO;
451 pp->geom = gp;
452 pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED,
453 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
454 LIST_INSERT_HEAD(&gp->provider, pp, provider);
455 g_post_event(g_new_provider_event, pp, M_WAITOK, pp, gp, NULL);
456 return (pp);
457 }
458
459 void
460 g_error_provider(struct g_provider *pp, int error)
461 {
462
463 /* G_VALID_PROVIDER(pp); We may not have g_topology */
464 pp->error = error;
465 }
466
467 struct g_provider *
468 g_provider_by_name(char const *arg)
469 {
470 struct g_class *cp;
471 struct g_geom *gp;
472 struct g_provider *pp;
473
474 LIST_FOREACH(cp, &g_classes, class) {
475 LIST_FOREACH(gp, &cp->geom, geom) {
476 LIST_FOREACH(pp, &gp->provider, provider) {
477 if (!strcmp(arg, pp->name))
478 return (pp);
479 }
480 }
481 }
482 return (NULL);
483 }
484
485 void
486 g_destroy_provider(struct g_provider *pp)
487 {
488 struct g_geom *gp;
489
490 g_topology_assert();
491 G_VALID_PROVIDER(pp);
492 KASSERT(LIST_EMPTY(&pp->consumers),
493 ("g_destroy_provider but attached"));
494 KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
495 KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
496 KASSERT (pp->acw == 0, ("g_destroy_provider with ace"));
497 g_cancel_event(pp);
498 LIST_REMOVE(pp, provider);
499 gp = pp->geom;
500 devstat_remove_entry(pp->stat);
501 g_free(pp);
502 if ((gp->flags & G_GEOM_WITHER))
503 g_do_wither();
504 }
505
506 /*
507 * We keep the "geoms" list sorted by topological order (== increasing
508 * numerical rank) at all times.
509 * When an attach is done, the attaching geoms rank is invalidated
510 * and it is moved to the tail of the list.
511 * All geoms later in the sequence has their ranks reevaluated in
512 * sequence. If we cannot assign rank to a geom because it's
513 * prerequisites do not have rank, we move that element to the tail
514 * of the sequence with invalid rank as well.
515 * At some point we encounter our original geom and if we stil fail
516 * to assign it a rank, there must be a loop and we fail back to
517 * g_attach() which detach again and calls redo_rank again
518 * to fix up the damage.
519 * It would be much simpler code wise to do it recursively, but we
520 * can't risk that on the kernel stack.
521 */
522
523 static int
524 redo_rank(struct g_geom *gp)
525 {
526 struct g_consumer *cp;
527 struct g_geom *gp1, *gp2;
528 int n, m;
529
530 g_topology_assert();
531 G_VALID_GEOM(gp);
532
533 /* Invalidate this geoms rank and move it to the tail */
534 gp1 = TAILQ_NEXT(gp, geoms);
535 if (gp1 != NULL) {
536 gp->rank = 0;
537 TAILQ_REMOVE(&geoms, gp, geoms);
538 TAILQ_INSERT_TAIL(&geoms, gp, geoms);
539 } else {
540 gp1 = gp;
541 }
542
543 /* re-rank the rest of the sequence */
544 for (; gp1 != NULL; gp1 = gp2) {
545 gp1->rank = 0;
546 m = 1;
547 LIST_FOREACH(cp, &gp1->consumer, consumer) {
548 if (cp->provider == NULL)
549 continue;
550 n = cp->provider->geom->rank;
551 if (n == 0) {
552 m = 0;
553 break;
554 } else if (n >= m)
555 m = n + 1;
556 }
557 gp1->rank = m;
558 gp2 = TAILQ_NEXT(gp1, geoms);
559
560 /* got a rank, moving on */
561 if (m != 0)
562 continue;
563
564 /* no rank to original geom means loop */
565 if (gp == gp1)
566 return (ELOOP);
567
568 /* no rank, put it at the end move on */
569 TAILQ_REMOVE(&geoms, gp1, geoms);
570 TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
571 }
572 return (0);
573 }
574
575 int
576 g_attach(struct g_consumer *cp, struct g_provider *pp)
577 {
578 int error;
579
580 g_topology_assert();
581 G_VALID_CONSUMER(cp);
582 G_VALID_PROVIDER(pp);
583 KASSERT(cp->provider == NULL, ("attach but attached"));
584 cp->provider = pp;
585 LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
586 error = redo_rank(cp->geom);
587 if (error) {
588 LIST_REMOVE(cp, consumers);
589 cp->provider = NULL;
590 redo_rank(cp->geom);
591 }
592 return (error);
593 }
594
595 void
596 g_detach(struct g_consumer *cp)
597 {
598 struct g_provider *pp;
599
600 g_topology_assert();
601 G_VALID_CONSUMER(cp);
602 g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp);
603 KASSERT(cp->provider != NULL, ("detach but not attached"));
604 KASSERT(cp->acr == 0, ("detach but nonzero acr"));
605 KASSERT(cp->acw == 0, ("detach but nonzero acw"));
606 KASSERT(cp->ace == 0, ("detach but nonzero ace"));
607 KASSERT(cp->nstart == cp->nend,
608 ("detach with active requests"));
609 pp = cp->provider;
610 LIST_REMOVE(cp, consumers);
611 cp->provider = NULL;
612 if (pp->geom->flags & G_GEOM_WITHER)
613 g_do_wither();
614 else if (pp->flags & G_PF_WITHER)
615 g_do_wither();
616 redo_rank(cp->geom);
617 }
618
619 /*
620 * g_access()
621 *
622 * Access-check with delta values. The question asked is "can provider
623 * "cp" change the access counters by the relative amounts dc[rwe] ?"
624 */
625
626 int
627 g_access(struct g_consumer *cp, int dcr, int dcw, int dce)
628 {
629 struct g_provider *pp;
630 int pr,pw,pe;
631 int error;
632
633 g_topology_assert();
634 G_VALID_CONSUMER(cp);
635 pp = cp->provider;
636 KASSERT(pp != NULL, ("access but not attached"));
637 G_VALID_PROVIDER(pp);
638
639 g_trace(G_T_ACCESS, "g_access(%p(%s), %d, %d, %d)",
640 cp, pp->name, dcr, dcw, dce);
641
642 KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
643 KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
644 KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
645 KASSERT(dcr != 0 || dcw != 0 || dce != 0, ("NOP access request"));
646 KASSERT(pp->geom->access != NULL, ("NULL geom->access"));
647
648 /*
649 * If our class cares about being spoiled, and we have been, we
650 * are probably just ahead of the event telling us that. Fail
651 * now rather than having to unravel this later.
652 */
653 if (cp->geom->spoiled != NULL && cp->spoiled &&
654 (dcr > 0 || dcw > 0 || dce > 0))
655 return (ENXIO);
656
657 /*
658 * Figure out what counts the provider would have had, if this
659 * consumer had (r0w0e0) at this time.
660 */
661 pr = pp->acr - cp->acr;
662 pw = pp->acw - cp->acw;
663 pe = pp->ace - cp->ace;
664
665 g_trace(G_T_ACCESS,
666 "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
667 dcr, dcw, dce,
668 cp->acr, cp->acw, cp->ace,
669 pp->acr, pp->acw, pp->ace,
670 pp, pp->name);
671
672 /* If foot-shooting is enabled, any open on rank#1 is OK */
673 if ((g_debugflags & 16) && pp->geom->rank == 1)
674 ;
675 /* If we try exclusive but already write: fail */
676 else if (dce > 0 && pw > 0)
677 return (EPERM);
678 /* If we try write but already exclusive: fail */
679 else if (dcw > 0 && pe > 0)
680 return (EPERM);
681 /* If we try to open more but provider is error'ed: fail */
682 else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0)
683 return (pp->error);
684
685 /* Ok then... */
686
687 error = pp->geom->access(pp, dcr, dcw, dce);
688 KASSERT(dcr > 0 || dcw > 0 || dce > 0 || error == 0,
689 ("Geom provider %s::%s failed closing ->access()",
690 pp->geom->class->name, pp->name));
691 if (!error) {
692 /*
693 * If we open first write, spoil any partner consumers.
694 * If we close last write, trigger re-taste.
695 */
696 if (pp->acw == 0 && dcw != 0)
697 g_spoil(pp, cp);
698 else if (pp->acw != 0 && pp->acw == -dcw &&
699 !(pp->geom->flags & G_GEOM_WITHER))
700 g_post_event(g_new_provider_event, pp, M_WAITOK,
701 pp, NULL);
702
703 pp->acr += dcr;
704 pp->acw += dcw;
705 pp->ace += dce;
706 cp->acr += dcr;
707 cp->acw += dcw;
708 cp->ace += dce;
709 if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)
710 KASSERT(pp->sectorsize > 0,
711 ("Provider %s lacks sectorsize", pp->name));
712 }
713 return (error);
714 }
715
716 int
717 g_handleattr_int(struct bio *bp, const char *attribute, int val)
718 {
719
720 return (g_handleattr(bp, attribute, &val, sizeof val));
721 }
722
723 int
724 g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val)
725 {
726
727 return (g_handleattr(bp, attribute, &val, sizeof val));
728 }
729
730 int
731 g_handleattr(struct bio *bp, const char *attribute, void *val, int len)
732 {
733 int error;
734
735 if (strcmp(bp->bio_attribute, attribute))
736 return (0);
737 if (bp->bio_length != len) {
738 printf("bio_length %jd len %d -> EFAULT\n",
739 (intmax_t)bp->bio_length, len);
740 error = EFAULT;
741 } else {
742 error = 0;
743 bcopy(val, bp->bio_data, len);
744 bp->bio_completed = len;
745 }
746 g_io_deliver(bp, error);
747 return (1);
748 }
749
750 int
751 g_std_access(struct g_provider *pp,
752 int dr __unused, int dw __unused, int de __unused)
753 {
754
755 g_topology_assert();
756 G_VALID_PROVIDER(pp);
757 return (0);
758 }
759
760 void
761 g_std_done(struct bio *bp)
762 {
763 struct bio *bp2;
764
765 bp2 = bp->bio_parent;
766 if (bp2->bio_error == 0)
767 bp2->bio_error = bp->bio_error;
768 bp2->bio_completed += bp->bio_completed;
769 g_destroy_bio(bp);
770 bp2->bio_inbed++;
771 if (bp2->bio_children == bp2->bio_inbed)
772 g_io_deliver(bp2, bp2->bio_error);
773 }
774
775 /* XXX: maybe this is only g_slice_spoiled */
776
777 void
778 g_std_spoiled(struct g_consumer *cp)
779 {
780 struct g_geom *gp;
781 struct g_provider *pp;
782
783 g_topology_assert();
784 G_VALID_CONSUMER(cp);
785 g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
786 g_detach(cp);
787 gp = cp->geom;
788 LIST_FOREACH(pp, &gp->provider, provider)
789 g_orphan_provider(pp, ENXIO);
790 g_destroy_consumer(cp);
791 if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
792 g_destroy_geom(gp);
793 else
794 gp->flags |= G_GEOM_WITHER;
795 }
796
797 /*
798 * Spoiling happens when a provider is opened for writing, but consumers
799 * which are configured by in-band data are attached (slicers for instance).
800 * Since the write might potentially change the in-band data, such consumers
801 * need to re-evaluate their existence after the writing session closes.
802 * We do this by (offering to) tear them down when the open for write happens
803 * in return for a re-taste when it closes again.
804 * Together with the fact that such consumers grab an 'e' bit whenever they
805 * are open, regardless of mode, this ends up DTRT.
806 */
807
808 static void
809 g_spoil_event(void *arg, int flag)
810 {
811 struct g_provider *pp;
812 struct g_consumer *cp, *cp2;
813
814 g_topology_assert();
815 if (flag == EV_CANCEL)
816 return;
817 pp = arg;
818 G_VALID_PROVIDER(pp);
819 for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) {
820 cp2 = LIST_NEXT(cp, consumers);
821 if (!cp->spoiled)
822 continue;
823 cp->spoiled = 0;
824 if (cp->geom->spoiled == NULL)
825 continue;
826 cp->geom->spoiled(cp);
827 g_topology_assert();
828 }
829 }
830
831 void
832 g_spoil(struct g_provider *pp, struct g_consumer *cp)
833 {
834 struct g_consumer *cp2;
835
836 g_topology_assert();
837 G_VALID_PROVIDER(pp);
838 G_VALID_CONSUMER(cp);
839
840 LIST_FOREACH(cp2, &pp->consumers, consumers) {
841 if (cp2 == cp)
842 continue;
843 /*
844 KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
845 KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
846 */
847 KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
848 cp2->spoiled++;
849 }
850 g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL);
851 }
852
853 int
854 g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len)
855 {
856 int error, i;
857
858 i = len;
859 error = g_io_getattr(attr, cp, &i, var);
860 if (error)
861 return (error);
862 if (i != len)
863 return (EINVAL);
864 return (0);
865 }
866
867 #ifdef DIAGNOSTIC
868 /*
869 * This function walks (topologically unsafely) the mesh and return a
870 * non-zero integer if it finds the argument pointer is an object.
871 * The return value indicates which type of object it is belived to be.
872 * If topology is not locked, this function is potentially dangerous,
873 * but since it is for debugging purposes and can be useful for instance
874 * from DDB, we do not assert topology lock is held.
875 */
876 int
877 g_valid_obj(void const *ptr)
878 {
879 struct g_class *mp;
880 struct g_geom *gp;
881 struct g_consumer *cp;
882 struct g_provider *pp;
883
884 LIST_FOREACH(mp, &g_classes, class) {
885 if (ptr == mp)
886 return (1);
887 LIST_FOREACH(gp, &mp->geom, geom) {
888 if (ptr == gp)
889 return (2);
890 LIST_FOREACH(cp, &gp->consumer, consumer)
891 if (ptr == cp)
892 return (3);
893 LIST_FOREACH(pp, &gp->provider, provider)
894 if (ptr == pp)
895 return (4);
896 }
897 }
898 return(0);
899 }
900 #endif
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