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/6.4/sys/geom/geom_subr.c 152840 2005-11-26 22:55:20Z jdp $");
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 int post;
64 };
65
66 /*
67 * This event offers a new class a chance to taste all preexisting providers.
68 */
69 static void
70 g_load_class(void *arg, int flag)
71 {
72 struct g_hh00 *hh;
73 struct g_class *mp2, *mp;
74 struct g_geom *gp;
75 struct g_provider *pp;
76
77 g_topology_assert();
78 if (flag == EV_CANCEL) /* XXX: can't happen ? */
79 return;
80 if (g_shutdown)
81 return;
82
83 hh = arg;
84 mp = hh->mp;
85 hh->error = 0;
86 if (hh->post) {
87 g_free(hh);
88 hh = NULL;
89 }
90 g_trace(G_T_TOPOLOGY, "g_load_class(%s)", mp->name);
91 KASSERT(mp->name != NULL && *mp->name != '\0',
92 ("GEOM class has no name"));
93 LIST_FOREACH(mp2, &g_classes, class) {
94 if (mp2 == mp) {
95 printf("The GEOM class %s is already loaded.\n",
96 mp2->name);
97 if (hh != NULL)
98 hh->error = EEXIST;
99 return;
100 } else if (strcmp(mp2->name, mp->name) == 0) {
101 printf("A GEOM class %s is already loaded.\n",
102 mp2->name);
103 if (hh != NULL)
104 hh->error = EEXIST;
105 return;
106 }
107 }
108
109 LIST_INIT(&mp->geom);
110 LIST_INSERT_HEAD(&g_classes, mp, class);
111 if (mp->init != NULL)
112 mp->init(mp);
113 if (mp->taste == NULL)
114 return;
115 LIST_FOREACH(mp2, &g_classes, class) {
116 if (mp == mp2)
117 continue;
118 LIST_FOREACH(gp, &mp2->geom, geom) {
119 LIST_FOREACH(pp, &gp->provider, provider) {
120 mp->taste(mp, pp, 0);
121 g_topology_assert();
122 }
123 }
124 }
125 }
126
127 static void
128 g_unload_class(void *arg, int flag)
129 {
130 struct g_hh00 *hh;
131 struct g_class *mp;
132 struct g_geom *gp;
133 struct g_provider *pp;
134 struct g_consumer *cp;
135 int error;
136
137 g_topology_assert();
138 hh = arg;
139 mp = hh->mp;
140 G_VALID_CLASS(mp);
141 g_trace(G_T_TOPOLOGY, "g_unload_class(%s)", mp->name);
142
143 /*
144 * We allow unloading if we have no geoms, or a class
145 * method we can use to get rid of them.
146 */
147 if (!LIST_EMPTY(&mp->geom) && mp->destroy_geom == NULL) {
148 hh->error = EOPNOTSUPP;
149 return;
150 }
151
152 /* We refuse to unload if anything is open */
153 LIST_FOREACH(gp, &mp->geom, geom) {
154 LIST_FOREACH(pp, &gp->provider, provider)
155 if (pp->acr || pp->acw || pp->ace) {
156 hh->error = EBUSY;
157 return;
158 }
159 LIST_FOREACH(cp, &gp->consumer, consumer)
160 if (cp->acr || cp->acw || cp->ace) {
161 hh->error = EBUSY;
162 return;
163 }
164 }
165
166 /* Bar new entries */
167 mp->taste = NULL;
168 mp->config = NULL;
169
170 error = 0;
171 for (;;) {
172 gp = LIST_FIRST(&mp->geom);
173 if (gp == NULL)
174 break;
175 error = mp->destroy_geom(NULL, mp, gp);
176 if (error != 0)
177 break;
178 }
179 if (error == 0) {
180 if (mp->fini != NULL)
181 mp->fini(mp);
182 LIST_REMOVE(mp, class);
183 }
184 hh->error = error;
185 return;
186 }
187
188 int
189 g_modevent(module_t mod, int type, void *data)
190 {
191 struct g_hh00 *hh;
192 int error;
193 static int g_ignition;
194 struct g_class *mp;
195
196 mp = data;
197 if (mp->version != G_VERSION) {
198 printf("GEOM class %s has Wrong version %x\n",
199 mp->name, mp->version);
200 return (EINVAL);
201 }
202 if (!g_ignition) {
203 g_ignition++;
204 g_init();
205 }
206 hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
207 hh->mp = data;
208 error = EOPNOTSUPP;
209 switch (type) {
210 case MOD_LOAD:
211 g_trace(G_T_TOPOLOGY, "g_modevent(%s, LOAD)", hh->mp->name);
212 /*
213 * Once the system is not cold, MOD_LOAD calls will be
214 * from the userland and the g_event thread will be able
215 * to acknowledge their completion.
216 */
217 if (cold) {
218 hh->post = 1;
219 error = g_post_event(g_load_class, hh, M_WAITOK, NULL);
220 } else {
221 error = g_waitfor_event(g_load_class, hh, M_WAITOK,
222 NULL);
223 if (error == 0)
224 error = hh->error;
225 g_free(hh);
226 }
227 break;
228 case MOD_UNLOAD:
229 g_trace(G_T_TOPOLOGY, "g_modevent(%s, UNLOAD)", hh->mp->name);
230 error = g_waitfor_event(g_unload_class, hh, M_WAITOK, NULL);
231 if (error == 0)
232 error = hh->error;
233 if (error == 0) {
234 KASSERT(LIST_EMPTY(&hh->mp->geom),
235 ("Unloaded class (%s) still has geom", hh->mp->name));
236 }
237 g_free(hh);
238 break;
239 default:
240 g_free(hh);
241 break;
242 }
243 return (error);
244 }
245
246 struct g_geom *
247 g_new_geomf(struct g_class *mp, const char *fmt, ...)
248 {
249 struct g_geom *gp;
250 va_list ap;
251 struct sbuf *sb;
252
253 g_topology_assert();
254 G_VALID_CLASS(mp);
255 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
256 va_start(ap, fmt);
257 sbuf_vprintf(sb, fmt, ap);
258 va_end(ap);
259 sbuf_finish(sb);
260 gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO);
261 gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
262 gp->class = mp;
263 gp->rank = 1;
264 LIST_INIT(&gp->consumer);
265 LIST_INIT(&gp->provider);
266 LIST_INSERT_HEAD(&mp->geom, gp, geom);
267 TAILQ_INSERT_HEAD(&geoms, gp, geoms);
268 strcpy(gp->name, sbuf_data(sb));
269 sbuf_delete(sb);
270 /* Fill in defaults from class */
271 gp->start = mp->start;
272 gp->spoiled = mp->spoiled;
273 gp->dumpconf = mp->dumpconf;
274 gp->access = mp->access;
275 gp->orphan = mp->orphan;
276 gp->ioctl = mp->ioctl;
277 return (gp);
278 }
279
280 void
281 g_destroy_geom(struct g_geom *gp)
282 {
283
284 g_topology_assert();
285 G_VALID_GEOM(gp);
286 g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
287 KASSERT(LIST_EMPTY(&gp->consumer),
288 ("g_destroy_geom(%s) with consumer(s) [%p]",
289 gp->name, LIST_FIRST(&gp->consumer)));
290 KASSERT(LIST_EMPTY(&gp->provider),
291 ("g_destroy_geom(%s) with provider(s) [%p]",
292 gp->name, LIST_FIRST(&gp->provider)));
293 g_cancel_event(gp);
294 LIST_REMOVE(gp, geom);
295 TAILQ_REMOVE(&geoms, gp, geoms);
296 g_free(gp->name);
297 g_free(gp);
298 }
299
300 /*
301 * This function is called (repeatedly) until the has withered away.
302 */
303 void
304 g_wither_geom(struct g_geom *gp, int error)
305 {
306 struct g_provider *pp;
307
308 g_topology_assert();
309 G_VALID_GEOM(gp);
310 g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name);
311 if (!(gp->flags & G_GEOM_WITHER)) {
312 gp->flags |= G_GEOM_WITHER;
313 LIST_FOREACH(pp, &gp->provider, provider)
314 if (!(pp->flags & G_PF_ORPHAN))
315 g_orphan_provider(pp, error);
316 }
317 g_do_wither();
318 }
319
320 /*
321 * This function is called (repeatedly) until the has withered away.
322 */
323 void
324 g_wither_geom_close(struct g_geom *gp, int error)
325 {
326 struct g_consumer *cp;
327
328 g_topology_assert();
329 G_VALID_GEOM(gp);
330 g_trace(G_T_TOPOLOGY, "g_wither_geom_close(%p(%s))", gp, gp->name);
331 LIST_FOREACH(cp, &gp->consumer, consumer)
332 if (cp->acr || cp->acw || cp->ace)
333 g_access(cp, -cp->acr, -cp->acw, -cp->ace);
334 g_wither_geom(gp, error);
335 }
336
337 /*
338 * This function is called (repeatedly) until we cant wash away more
339 * withered bits at present. Return value contains two bits. Bit 0
340 * set means "withering stuff we can't wash now", bit 1 means "call
341 * me again, there may be stuff I didn't get the first time around.
342 */
343 int
344 g_wither_washer()
345 {
346 struct g_class *mp;
347 struct g_geom *gp, *gp2;
348 struct g_provider *pp, *pp2;
349 struct g_consumer *cp, *cp2;
350 int result;
351
352 result = 0;
353 g_topology_assert();
354 LIST_FOREACH(mp, &g_classes, class) {
355 LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
356 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
357 if (!(pp->flags & G_PF_WITHER))
358 continue;
359 if (LIST_EMPTY(&pp->consumers))
360 g_destroy_provider(pp);
361 else
362 result |= 1;
363 }
364 if (!(gp->flags & G_GEOM_WITHER))
365 continue;
366 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
367 if (LIST_EMPTY(&pp->consumers))
368 g_destroy_provider(pp);
369 else
370 result |= 1;
371 }
372 LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp2) {
373 if (cp->acr || cp->acw || cp->ace) {
374 result |= 1;
375 continue;
376 }
377 if (cp->provider != NULL)
378 g_detach(cp);
379 g_destroy_consumer(cp);
380 result |= 2;
381 }
382 if (LIST_EMPTY(&gp->provider) &&
383 LIST_EMPTY(&gp->consumer))
384 g_destroy_geom(gp);
385 else
386 result |= 1;
387 }
388 }
389 return (result);
390 }
391
392 struct g_consumer *
393 g_new_consumer(struct g_geom *gp)
394 {
395 struct g_consumer *cp;
396
397 g_topology_assert();
398 G_VALID_GEOM(gp);
399 KASSERT(!(gp->flags & G_GEOM_WITHER),
400 ("g_new_consumer on WITHERing geom(%s) (class %s)",
401 gp->name, gp->class->name));
402 KASSERT(gp->orphan != NULL,
403 ("g_new_consumer on geom(%s) (class %s) without orphan",
404 gp->name, gp->class->name));
405
406 cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO);
407 cp->geom = gp;
408 cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED,
409 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
410 LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
411 return(cp);
412 }
413
414 void
415 g_destroy_consumer(struct g_consumer *cp)
416 {
417 struct g_geom *gp;
418
419 g_topology_assert();
420 G_VALID_CONSUMER(cp);
421 g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
422 KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
423 KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
424 KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
425 KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
426 g_cancel_event(cp);
427 gp = cp->geom;
428 LIST_REMOVE(cp, consumer);
429 devstat_remove_entry(cp->stat);
430 g_free(cp);
431 if (gp->flags & G_GEOM_WITHER)
432 g_do_wither();
433 }
434
435 static void
436 g_new_provider_event(void *arg, int flag)
437 {
438 struct g_class *mp;
439 struct g_provider *pp;
440 struct g_consumer *cp;
441 int i;
442
443 g_topology_assert();
444 if (flag == EV_CANCEL)
445 return;
446 if (g_shutdown)
447 return;
448 pp = arg;
449 G_VALID_PROVIDER(pp);
450 LIST_FOREACH(mp, &g_classes, class) {
451 if (mp->taste == NULL)
452 continue;
453 i = 1;
454 LIST_FOREACH(cp, &pp->consumers, consumers)
455 if (cp->geom->class == mp)
456 i = 0;
457 if (!i)
458 continue;
459 mp->taste(mp, pp, 0);
460 g_topology_assert();
461 }
462 }
463
464
465 struct g_provider *
466 g_new_providerf(struct g_geom *gp, const char *fmt, ...)
467 {
468 struct g_provider *pp;
469 struct sbuf *sb;
470 va_list ap;
471
472 g_topology_assert();
473 G_VALID_GEOM(gp);
474 KASSERT(gp->access != NULL,
475 ("new provider on geom(%s) without ->access (class %s)",
476 gp->name, gp->class->name));
477 KASSERT(gp->start != NULL,
478 ("new provider on geom(%s) without ->start (class %s)",
479 gp->name, gp->class->name));
480 KASSERT(!(gp->flags & G_GEOM_WITHER),
481 ("new provider on WITHERing geom(%s) (class %s)",
482 gp->name, gp->class->name));
483 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
484 va_start(ap, fmt);
485 sbuf_vprintf(sb, fmt, ap);
486 va_end(ap);
487 sbuf_finish(sb);
488 pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
489 pp->name = (char *)(pp + 1);
490 strcpy(pp->name, sbuf_data(sb));
491 sbuf_delete(sb);
492 LIST_INIT(&pp->consumers);
493 pp->error = ENXIO;
494 pp->geom = gp;
495 pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED,
496 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
497 LIST_INSERT_HEAD(&gp->provider, pp, provider);
498 g_post_event(g_new_provider_event, pp, M_WAITOK, pp, gp, NULL);
499 return (pp);
500 }
501
502 void
503 g_error_provider(struct g_provider *pp, int error)
504 {
505
506 /* G_VALID_PROVIDER(pp); We may not have g_topology */
507 pp->error = error;
508 }
509
510 struct g_provider *
511 g_provider_by_name(char const *arg)
512 {
513 struct g_class *cp;
514 struct g_geom *gp;
515 struct g_provider *pp;
516
517 LIST_FOREACH(cp, &g_classes, class) {
518 LIST_FOREACH(gp, &cp->geom, geom) {
519 LIST_FOREACH(pp, &gp->provider, provider) {
520 if (!strcmp(arg, pp->name))
521 return (pp);
522 }
523 }
524 }
525 return (NULL);
526 }
527
528 void
529 g_destroy_provider(struct g_provider *pp)
530 {
531 struct g_geom *gp;
532
533 g_topology_assert();
534 G_VALID_PROVIDER(pp);
535 KASSERT(LIST_EMPTY(&pp->consumers),
536 ("g_destroy_provider but attached"));
537 KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
538 KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
539 KASSERT (pp->acw == 0, ("g_destroy_provider with ace"));
540 g_cancel_event(pp);
541 LIST_REMOVE(pp, provider);
542 gp = pp->geom;
543 devstat_remove_entry(pp->stat);
544 g_free(pp);
545 if ((gp->flags & G_GEOM_WITHER))
546 g_do_wither();
547 }
548
549 /*
550 * We keep the "geoms" list sorted by topological order (== increasing
551 * numerical rank) at all times.
552 * When an attach is done, the attaching geoms rank is invalidated
553 * and it is moved to the tail of the list.
554 * All geoms later in the sequence has their ranks reevaluated in
555 * sequence. If we cannot assign rank to a geom because it's
556 * prerequisites do not have rank, we move that element to the tail
557 * of the sequence with invalid rank as well.
558 * At some point we encounter our original geom and if we stil fail
559 * to assign it a rank, there must be a loop and we fail back to
560 * g_attach() which detach again and calls redo_rank again
561 * to fix up the damage.
562 * It would be much simpler code wise to do it recursively, but we
563 * can't risk that on the kernel stack.
564 */
565
566 static int
567 redo_rank(struct g_geom *gp)
568 {
569 struct g_consumer *cp;
570 struct g_geom *gp1, *gp2;
571 int n, m;
572
573 g_topology_assert();
574 G_VALID_GEOM(gp);
575
576 /* Invalidate this geoms rank and move it to the tail */
577 gp1 = TAILQ_NEXT(gp, geoms);
578 if (gp1 != NULL) {
579 gp->rank = 0;
580 TAILQ_REMOVE(&geoms, gp, geoms);
581 TAILQ_INSERT_TAIL(&geoms, gp, geoms);
582 } else {
583 gp1 = gp;
584 }
585
586 /* re-rank the rest of the sequence */
587 for (; gp1 != NULL; gp1 = gp2) {
588 gp1->rank = 0;
589 m = 1;
590 LIST_FOREACH(cp, &gp1->consumer, consumer) {
591 if (cp->provider == NULL)
592 continue;
593 n = cp->provider->geom->rank;
594 if (n == 0) {
595 m = 0;
596 break;
597 } else if (n >= m)
598 m = n + 1;
599 }
600 gp1->rank = m;
601 gp2 = TAILQ_NEXT(gp1, geoms);
602
603 /* got a rank, moving on */
604 if (m != 0)
605 continue;
606
607 /* no rank to original geom means loop */
608 if (gp == gp1)
609 return (ELOOP);
610
611 /* no rank, put it at the end move on */
612 TAILQ_REMOVE(&geoms, gp1, geoms);
613 TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
614 }
615 return (0);
616 }
617
618 int
619 g_attach(struct g_consumer *cp, struct g_provider *pp)
620 {
621 int error;
622
623 g_topology_assert();
624 G_VALID_CONSUMER(cp);
625 G_VALID_PROVIDER(pp);
626 KASSERT(cp->provider == NULL, ("attach but attached"));
627 cp->provider = pp;
628 LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
629 error = redo_rank(cp->geom);
630 if (error) {
631 LIST_REMOVE(cp, consumers);
632 cp->provider = NULL;
633 redo_rank(cp->geom);
634 }
635 return (error);
636 }
637
638 void
639 g_detach(struct g_consumer *cp)
640 {
641 struct g_provider *pp;
642
643 g_topology_assert();
644 G_VALID_CONSUMER(cp);
645 g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp);
646 KASSERT(cp->provider != NULL, ("detach but not attached"));
647 KASSERT(cp->acr == 0, ("detach but nonzero acr"));
648 KASSERT(cp->acw == 0, ("detach but nonzero acw"));
649 KASSERT(cp->ace == 0, ("detach but nonzero ace"));
650 KASSERT(cp->nstart == cp->nend,
651 ("detach with active requests"));
652 pp = cp->provider;
653 LIST_REMOVE(cp, consumers);
654 cp->provider = NULL;
655 if (pp->geom->flags & G_GEOM_WITHER)
656 g_do_wither();
657 else if (pp->flags & G_PF_WITHER)
658 g_do_wither();
659 redo_rank(cp->geom);
660 }
661
662 /*
663 * g_access()
664 *
665 * Access-check with delta values. The question asked is "can provider
666 * "cp" change the access counters by the relative amounts dc[rwe] ?"
667 */
668
669 int
670 g_access(struct g_consumer *cp, int dcr, int dcw, int dce)
671 {
672 struct g_provider *pp;
673 int pr,pw,pe;
674 int error;
675
676 g_topology_assert();
677 G_VALID_CONSUMER(cp);
678 pp = cp->provider;
679 KASSERT(pp != NULL, ("access but not attached"));
680 G_VALID_PROVIDER(pp);
681
682 g_trace(G_T_ACCESS, "g_access(%p(%s), %d, %d, %d)",
683 cp, pp->name, dcr, dcw, dce);
684
685 KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
686 KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
687 KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
688 KASSERT(dcr != 0 || dcw != 0 || dce != 0, ("NOP access request"));
689 KASSERT(pp->geom->access != NULL, ("NULL geom->access"));
690
691 /*
692 * If our class cares about being spoiled, and we have been, we
693 * are probably just ahead of the event telling us that. Fail
694 * now rather than having to unravel this later.
695 */
696 if (cp->geom->spoiled != NULL && cp->spoiled &&
697 (dcr > 0 || dcw > 0 || dce > 0))
698 return (ENXIO);
699
700 /*
701 * Figure out what counts the provider would have had, if this
702 * consumer had (r0w0e0) at this time.
703 */
704 pr = pp->acr - cp->acr;
705 pw = pp->acw - cp->acw;
706 pe = pp->ace - cp->ace;
707
708 g_trace(G_T_ACCESS,
709 "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
710 dcr, dcw, dce,
711 cp->acr, cp->acw, cp->ace,
712 pp->acr, pp->acw, pp->ace,
713 pp, pp->name);
714
715 /* If foot-shooting is enabled, any open on rank#1 is OK */
716 if ((g_debugflags & 16) && pp->geom->rank == 1)
717 ;
718 /* If we try exclusive but already write: fail */
719 else if (dce > 0 && pw > 0)
720 return (EPERM);
721 /* If we try write but already exclusive: fail */
722 else if (dcw > 0 && pe > 0)
723 return (EPERM);
724 /* If we try to open more but provider is error'ed: fail */
725 else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0)
726 return (pp->error);
727
728 /* Ok then... */
729
730 error = pp->geom->access(pp, dcr, dcw, dce);
731 KASSERT(dcr > 0 || dcw > 0 || dce > 0 || error == 0,
732 ("Geom provider %s::%s failed closing ->access()",
733 pp->geom->class->name, pp->name));
734 if (!error) {
735 /*
736 * If we open first write, spoil any partner consumers.
737 * If we close last write and provider is not errored,
738 * trigger re-taste.
739 */
740 if (pp->acw == 0 && dcw != 0)
741 g_spoil(pp, cp);
742 else if (pp->acw != 0 && pp->acw == -dcw && pp->error == 0 &&
743 !(pp->geom->flags & G_GEOM_WITHER))
744 g_post_event(g_new_provider_event, pp, M_WAITOK,
745 pp, NULL);
746
747 pp->acr += dcr;
748 pp->acw += dcw;
749 pp->ace += dce;
750 cp->acr += dcr;
751 cp->acw += dcw;
752 cp->ace += dce;
753 if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)
754 KASSERT(pp->sectorsize > 0,
755 ("Provider %s lacks sectorsize", pp->name));
756 }
757 return (error);
758 }
759
760 int
761 g_handleattr_int(struct bio *bp, const char *attribute, int val)
762 {
763
764 return (g_handleattr(bp, attribute, &val, sizeof val));
765 }
766
767 int
768 g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val)
769 {
770
771 return (g_handleattr(bp, attribute, &val, sizeof val));
772 }
773
774 int
775 g_handleattr(struct bio *bp, const char *attribute, void *val, int len)
776 {
777 int error;
778
779 if (strcmp(bp->bio_attribute, attribute))
780 return (0);
781 if (bp->bio_length != len) {
782 printf("bio_length %jd len %d -> EFAULT\n",
783 (intmax_t)bp->bio_length, len);
784 error = EFAULT;
785 } else {
786 error = 0;
787 bcopy(val, bp->bio_data, len);
788 bp->bio_completed = len;
789 }
790 g_io_deliver(bp, error);
791 return (1);
792 }
793
794 int
795 g_std_access(struct g_provider *pp,
796 int dr __unused, int dw __unused, int de __unused)
797 {
798
799 g_topology_assert();
800 G_VALID_PROVIDER(pp);
801 return (0);
802 }
803
804 void
805 g_std_done(struct bio *bp)
806 {
807 struct bio *bp2;
808
809 bp2 = bp->bio_parent;
810 if (bp2->bio_error == 0)
811 bp2->bio_error = bp->bio_error;
812 bp2->bio_completed += bp->bio_completed;
813 g_destroy_bio(bp);
814 bp2->bio_inbed++;
815 if (bp2->bio_children == bp2->bio_inbed)
816 g_io_deliver(bp2, bp2->bio_error);
817 }
818
819 /* XXX: maybe this is only g_slice_spoiled */
820
821 void
822 g_std_spoiled(struct g_consumer *cp)
823 {
824 struct g_geom *gp;
825 struct g_provider *pp;
826
827 g_topology_assert();
828 G_VALID_CONSUMER(cp);
829 g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
830 g_detach(cp);
831 gp = cp->geom;
832 LIST_FOREACH(pp, &gp->provider, provider)
833 g_orphan_provider(pp, ENXIO);
834 g_destroy_consumer(cp);
835 if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
836 g_destroy_geom(gp);
837 else
838 gp->flags |= G_GEOM_WITHER;
839 }
840
841 /*
842 * Spoiling happens when a provider is opened for writing, but consumers
843 * which are configured by in-band data are attached (slicers for instance).
844 * Since the write might potentially change the in-band data, such consumers
845 * need to re-evaluate their existence after the writing session closes.
846 * We do this by (offering to) tear them down when the open for write happens
847 * in return for a re-taste when it closes again.
848 * Together with the fact that such consumers grab an 'e' bit whenever they
849 * are open, regardless of mode, this ends up DTRT.
850 */
851
852 static void
853 g_spoil_event(void *arg, int flag)
854 {
855 struct g_provider *pp;
856 struct g_consumer *cp, *cp2;
857
858 g_topology_assert();
859 if (flag == EV_CANCEL)
860 return;
861 pp = arg;
862 G_VALID_PROVIDER(pp);
863 for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) {
864 cp2 = LIST_NEXT(cp, consumers);
865 if (!cp->spoiled)
866 continue;
867 cp->spoiled = 0;
868 if (cp->geom->spoiled == NULL)
869 continue;
870 cp->geom->spoiled(cp);
871 g_topology_assert();
872 }
873 }
874
875 void
876 g_spoil(struct g_provider *pp, struct g_consumer *cp)
877 {
878 struct g_consumer *cp2;
879
880 g_topology_assert();
881 G_VALID_PROVIDER(pp);
882 G_VALID_CONSUMER(cp);
883
884 LIST_FOREACH(cp2, &pp->consumers, consumers) {
885 if (cp2 == cp)
886 continue;
887 /*
888 KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
889 KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
890 */
891 KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
892 cp2->spoiled++;
893 }
894 g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL);
895 }
896
897 int
898 g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len)
899 {
900 int error, i;
901
902 i = len;
903 error = g_io_getattr(attr, cp, &i, var);
904 if (error)
905 return (error);
906 if (i != len)
907 return (EINVAL);
908 return (0);
909 }
910
911 #ifdef DIAGNOSTIC
912 /*
913 * This function walks (topologically unsafely) the mesh and return a
914 * non-zero integer if it finds the argument pointer is an object.
915 * The return value indicates which type of object it is belived to be.
916 * If topology is not locked, this function is potentially dangerous,
917 * but since it is for debugging purposes and can be useful for instance
918 * from DDB, we do not assert topology lock is held.
919 */
920 int
921 g_valid_obj(void const *ptr)
922 {
923 struct g_class *mp;
924 struct g_geom *gp;
925 struct g_consumer *cp;
926 struct g_provider *pp;
927
928 LIST_FOREACH(mp, &g_classes, class) {
929 if (ptr == mp)
930 return (1);
931 LIST_FOREACH(gp, &mp->geom, geom) {
932 if (ptr == gp)
933 return (2);
934 LIST_FOREACH(cp, &gp->consumer, consumer)
935 if (ptr == cp)
936 return (3);
937 LIST_FOREACH(pp, &gp->provider, provider)
938 if (ptr == pp)
939 return (4);
940 }
941 }
942 return(0);
943 }
944 #endif
Cache object: c1da11651095ad85de6083ef1e79d0d4
|