geom_subr.c revision 131820
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: head/sys/geom/geom_subr.c 131820 2004-07-08 16:17:14Z phk $"); 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 56struct class_list_head g_classes = LIST_HEAD_INITIALIZER(g_classes); 57static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms); 58char *g_wait_event, *g_wait_up, *g_wait_down, *g_wait_sim; 59 60struct 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 */ 68static void 69g_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 113static void 114g_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 174int 175g_modevent(module_t mod, int type, void *data) 176{ 177 struct g_hh00 *hh; 178 int error; 179 static int g_ignition; 180 181 if (!g_ignition) { 182 g_ignition++; 183 g_init(); 184 } 185 hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO); 186 hh->mp = data; 187 error = EOPNOTSUPP; 188 switch (type) { 189 case MOD_LOAD: 190 g_trace(G_T_TOPOLOGY, "g_modevent(%s, LOAD)", hh->mp->name); 191 g_post_event(g_load_class, hh, M_WAITOK, NULL); 192 error = 0; 193 break; 194 case MOD_UNLOAD: 195 g_trace(G_T_TOPOLOGY, "g_modevent(%s, UNLOAD)", hh->mp->name); 196 error = g_waitfor_event(g_unload_class, hh, M_WAITOK, NULL); 197 if (error == 0) 198 error = hh->error; 199 if (error == 0) { 200 g_waitidle(); 201 KASSERT(LIST_EMPTY(&hh->mp->geom), 202 ("Unloaded class (%s) still has geom", hh->mp->name)); 203 } 204 g_free(hh); 205 break; 206 default: 207 g_free(hh); 208 break; 209 } 210 return (error); 211} 212 213struct g_geom * 214g_new_geomf(struct g_class *mp, const char *fmt, ...) 215{ 216 struct g_geom *gp; 217 va_list ap; 218 struct sbuf *sb; 219 220 g_topology_assert(); 221 G_VALID_CLASS(mp); 222 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 223 va_start(ap, fmt); 224 sbuf_vprintf(sb, fmt, ap); 225 va_end(ap); 226 sbuf_finish(sb); 227 gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO); 228 gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO); 229 gp->class = mp; 230 gp->rank = 1; 231 LIST_INIT(&gp->consumer); 232 LIST_INIT(&gp->provider); 233 LIST_INSERT_HEAD(&mp->geom, gp, geom); 234 TAILQ_INSERT_HEAD(&geoms, gp, geoms); 235 strcpy(gp->name, sbuf_data(sb)); 236 sbuf_delete(sb); 237 return (gp); 238} 239 240void 241g_destroy_geom(struct g_geom *gp) 242{ 243 244 g_topology_assert(); 245 G_VALID_GEOM(gp); 246 g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name); 247 KASSERT(LIST_EMPTY(&gp->consumer), 248 ("g_destroy_geom(%s) with consumer(s) [%p]", 249 gp->name, LIST_FIRST(&gp->consumer))); 250 KASSERT(LIST_EMPTY(&gp->provider), 251 ("g_destroy_geom(%s) with provider(s) [%p]", 252 gp->name, LIST_FIRST(&gp->provider))); 253 g_cancel_event(gp); 254 LIST_REMOVE(gp, geom); 255 TAILQ_REMOVE(&geoms, gp, geoms); 256 g_free(gp->name); 257 g_free(gp); 258} 259 260/* 261 * This function is called (repeatedly) until the has withered away. 262 */ 263void 264g_wither_geom(struct g_geom *gp, int error) 265{ 266 struct g_provider *pp; 267 268 g_topology_assert(); 269 G_VALID_GEOM(gp); 270 g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name); 271 if (!(gp->flags & G_GEOM_WITHER)) { 272 gp->flags |= G_GEOM_WITHER; 273 LIST_FOREACH(pp, &gp->provider, provider) 274 if (!(pp->flags & G_PF_ORPHAN)) 275 g_orphan_provider(pp, error); 276 } 277 g_do_wither(); 278} 279 280/* 281 * This function is called (repeatedly) until we cant wash away more 282 * withered bits at present. Return value contains two bits. Bit 0 283 * set means "withering stuff we can't wash now", bit 1 means "call 284 * me again, there may be stuff I didn't get the first time around. 285 */ 286int 287g_wither_washer() 288{ 289 struct g_class *mp; 290 struct g_geom *gp, *gp2; 291 struct g_provider *pp, *pp2; 292 struct g_consumer *cp, *cp2; 293 int result; 294 295 result = 0; 296 g_topology_assert(); 297 LIST_FOREACH(mp, &g_classes, class) { 298 LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) { 299 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) { 300 if (!(pp->flags & G_PF_WITHER)) 301 continue; 302 if (LIST_EMPTY(&pp->consumers)) 303 g_destroy_provider(pp); 304 else 305 result |= 1; 306 } 307 if (!(gp->flags & G_GEOM_WITHER)) 308 continue; 309 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) { 310 if (LIST_EMPTY(&pp->consumers)) 311 g_destroy_provider(pp); 312 else 313 result |= 1; 314 } 315 LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp2) { 316 if (cp->acr || cp->acw || cp->ace) { 317 result |= 1; 318 continue; 319 } 320 g_detach(cp); 321 g_destroy_consumer(cp); 322 result |= 2; 323 } 324 if (LIST_EMPTY(&gp->provider) && 325 LIST_EMPTY(&gp->consumer)) 326 g_destroy_geom(gp); 327 else 328 result |= 1; 329 } 330 } 331 return (result); 332} 333 334struct g_consumer * 335g_new_consumer(struct g_geom *gp) 336{ 337 struct g_consumer *cp; 338 339 g_topology_assert(); 340 G_VALID_GEOM(gp); 341 KASSERT(!(gp->flags & G_GEOM_WITHER), 342 ("g_new_consumer on WITHERing geom(%s) (class %s)", 343 gp->name, gp->class->name)); 344 KASSERT(gp->orphan != NULL, 345 ("g_new_consumer on geom(%s) (class %s) without orphan", 346 gp->name, gp->class->name)); 347 348 cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO); 349 cp->geom = gp; 350 cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED, 351 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX); 352 LIST_INSERT_HEAD(&gp->consumer, cp, consumer); 353 return(cp); 354} 355 356void 357g_destroy_consumer(struct g_consumer *cp) 358{ 359 struct g_geom *gp; 360 361 g_topology_assert(); 362 G_VALID_CONSUMER(cp); 363 g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp); 364 KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached")); 365 KASSERT (cp->acr == 0, ("g_destroy_consumer with acr")); 366 KASSERT (cp->acw == 0, ("g_destroy_consumer with acw")); 367 KASSERT (cp->ace == 0, ("g_destroy_consumer with ace")); 368 g_cancel_event(cp); 369 gp = cp->geom; 370 LIST_REMOVE(cp, consumer); 371 devstat_remove_entry(cp->stat); 372 g_free(cp); 373 if (gp->flags & G_GEOM_WITHER) 374 g_do_wither(); 375} 376 377static void 378g_new_provider_event(void *arg, int flag) 379{ 380 struct g_class *mp; 381 struct g_provider *pp; 382 struct g_consumer *cp; 383 int i; 384 385 g_topology_assert(); 386 if (flag == EV_CANCEL) 387 return; 388 if (g_shutdown) 389 return; 390 pp = arg; 391 G_VALID_PROVIDER(pp); 392 LIST_FOREACH(mp, &g_classes, class) { 393 if (mp->taste == NULL) 394 continue; 395 i = 1; 396 LIST_FOREACH(cp, &pp->consumers, consumers) 397 if (cp->geom->class == mp) 398 i = 0; 399 if (!i) 400 continue; 401 mp->taste(mp, pp, 0); 402 g_topology_assert(); 403 } 404} 405 406 407struct g_provider * 408g_new_providerf(struct g_geom *gp, const char *fmt, ...) 409{ 410 struct g_provider *pp; 411 struct sbuf *sb; 412 va_list ap; 413 414 g_topology_assert(); 415 G_VALID_GEOM(gp); 416 KASSERT(gp->access != NULL, 417 ("new provider on geom(%s) without ->access (class %s)", 418 gp->name, gp->class->name)); 419 KASSERT(gp->start != NULL, 420 ("new provider on geom(%s) without ->start (class %s)", 421 gp->name, gp->class->name)); 422 KASSERT(!(gp->flags & G_GEOM_WITHER), 423 ("new provider on WITHERing geom(%s) (class %s)", 424 gp->name, gp->class->name)); 425 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 426 va_start(ap, fmt); 427 sbuf_vprintf(sb, fmt, ap); 428 va_end(ap); 429 sbuf_finish(sb); 430 pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO); 431 pp->name = (char *)(pp + 1); 432 strcpy(pp->name, sbuf_data(sb)); 433 sbuf_delete(sb); 434 LIST_INIT(&pp->consumers); 435 pp->error = ENXIO; 436 pp->geom = gp; 437 pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED, 438 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX); 439 LIST_INSERT_HEAD(&gp->provider, pp, provider); 440 g_post_event(g_new_provider_event, pp, M_WAITOK, pp, gp, NULL); 441 return (pp); 442} 443 444void 445g_error_provider(struct g_provider *pp, int error) 446{ 447 448 /* G_VALID_PROVIDER(pp); We may not have g_topology */ 449 pp->error = error; 450} 451 452struct g_provider * 453g_provider_by_name(char const *arg) 454{ 455 struct g_class *cp; 456 struct g_geom *gp; 457 struct g_provider *pp; 458 459 LIST_FOREACH(cp, &g_classes, class) { 460 LIST_FOREACH(gp, &cp->geom, geom) { 461 LIST_FOREACH(pp, &gp->provider, provider) { 462 if (!strcmp(arg, pp->name)) 463 return (pp); 464 } 465 } 466 } 467 return (NULL); 468} 469 470void 471g_destroy_provider(struct g_provider *pp) 472{ 473 struct g_geom *gp; 474 475 g_topology_assert(); 476 G_VALID_PROVIDER(pp); 477 KASSERT(LIST_EMPTY(&pp->consumers), 478 ("g_destroy_provider but attached")); 479 KASSERT (pp->acr == 0, ("g_destroy_provider with acr")); 480 KASSERT (pp->acw == 0, ("g_destroy_provider with acw")); 481 KASSERT (pp->acw == 0, ("g_destroy_provider with ace")); 482 g_cancel_event(pp); 483 LIST_REMOVE(pp, provider); 484 gp = pp->geom; 485 devstat_remove_entry(pp->stat); 486 g_free(pp); 487 if ((gp->flags & G_GEOM_WITHER)) 488 g_do_wither(); 489} 490 491/* 492 * We keep the "geoms" list sorted by topological order (== increasing 493 * numerical rank) at all times. 494 * When an attach is done, the attaching geoms rank is invalidated 495 * and it is moved to the tail of the list. 496 * All geoms later in the sequence has their ranks reevaluated in 497 * sequence. If we cannot assign rank to a geom because it's 498 * prerequisites do not have rank, we move that element to the tail 499 * of the sequence with invalid rank as well. 500 * At some point we encounter our original geom and if we stil fail 501 * to assign it a rank, there must be a loop and we fail back to 502 * g_attach() which detach again and calls redo_rank again 503 * to fix up the damage. 504 * It would be much simpler code wise to do it recursively, but we 505 * can't risk that on the kernel stack. 506 */ 507 508static int 509redo_rank(struct g_geom *gp) 510{ 511 struct g_consumer *cp; 512 struct g_geom *gp1, *gp2; 513 int n, m; 514 515 g_topology_assert(); 516 G_VALID_GEOM(gp); 517 518 /* Invalidate this geoms rank and move it to the tail */ 519 gp1 = TAILQ_NEXT(gp, geoms); 520 if (gp1 != NULL) { 521 gp->rank = 0; 522 TAILQ_REMOVE(&geoms, gp, geoms); 523 TAILQ_INSERT_TAIL(&geoms, gp, geoms); 524 } else { 525 gp1 = gp; 526 } 527 528 /* re-rank the rest of the sequence */ 529 for (; gp1 != NULL; gp1 = gp2) { 530 gp1->rank = 0; 531 m = 1; 532 LIST_FOREACH(cp, &gp1->consumer, consumer) { 533 if (cp->provider == NULL) 534 continue; 535 n = cp->provider->geom->rank; 536 if (n == 0) { 537 m = 0; 538 break; 539 } else if (n >= m) 540 m = n + 1; 541 } 542 gp1->rank = m; 543 gp2 = TAILQ_NEXT(gp1, geoms); 544 545 /* got a rank, moving on */ 546 if (m != 0) 547 continue; 548 549 /* no rank to original geom means loop */ 550 if (gp == gp1) 551 return (ELOOP); 552 553 /* no rank, put it at the end move on */ 554 TAILQ_REMOVE(&geoms, gp1, geoms); 555 TAILQ_INSERT_TAIL(&geoms, gp1, geoms); 556 } 557 return (0); 558} 559 560int 561g_attach(struct g_consumer *cp, struct g_provider *pp) 562{ 563 int error; 564 565 g_topology_assert(); 566 G_VALID_CONSUMER(cp); 567 G_VALID_PROVIDER(pp); 568 KASSERT(cp->provider == NULL, ("attach but attached")); 569 cp->provider = pp; 570 LIST_INSERT_HEAD(&pp->consumers, cp, consumers); 571 error = redo_rank(cp->geom); 572 if (error) { 573 LIST_REMOVE(cp, consumers); 574 cp->provider = NULL; 575 redo_rank(cp->geom); 576 } 577 return (error); 578} 579 580void 581g_detach(struct g_consumer *cp) 582{ 583 struct g_provider *pp; 584 585 g_topology_assert(); 586 G_VALID_CONSUMER(cp); 587 g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp); 588 KASSERT(cp->provider != NULL, ("detach but not attached")); 589 KASSERT(cp->acr == 0, ("detach but nonzero acr")); 590 KASSERT(cp->acw == 0, ("detach but nonzero acw")); 591 KASSERT(cp->ace == 0, ("detach but nonzero ace")); 592 KASSERT(cp->nstart == cp->nend, 593 ("detach with active requests")); 594 pp = cp->provider; 595 LIST_REMOVE(cp, consumers); 596 cp->provider = NULL; 597 if (pp->geom->flags & G_GEOM_WITHER) 598 g_do_wither(); 599 else if (pp->flags & G_PF_WITHER) 600 g_do_wither(); 601 redo_rank(cp->geom); 602} 603 604/* 605 * g_access() 606 * 607 * Access-check with delta values. The question asked is "can provider 608 * "cp" change the access counters by the relative amounts dc[rwe] ?" 609 */ 610 611int 612g_access(struct g_consumer *cp, int dcr, int dcw, int dce) 613{ 614 struct g_provider *pp; 615 int pr,pw,pe; 616 int error; 617 618 g_topology_assert(); 619 G_VALID_CONSUMER(cp); 620 pp = cp->provider; 621 KASSERT(pp != NULL, ("access but not attached")); 622 G_VALID_PROVIDER(pp); 623 624 g_trace(G_T_ACCESS, "g_access(%p(%s), %d, %d, %d)", 625 cp, pp->name, dcr, dcw, dce); 626 627 KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr")); 628 KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw")); 629 KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace")); 630 KASSERT(dcr != 0 || dcw != 0 || dce != 0, ("NOP access request")); 631 KASSERT(pp->geom->access != NULL, ("NULL geom->access")); 632 633 /* 634 * If our class cares about being spoiled, and we have been, we 635 * are probably just ahead of the event telling us that. Fail 636 * now rather than having to unravel this later. 637 */ 638 if (cp->geom->spoiled != NULL && cp->spoiled && 639 (dcr > 0 || dcw > 0 || dce > 0)) 640 return (ENXIO); 641 642 /* 643 * Figure out what counts the provider would have had, if this 644 * consumer had (r0w0e0) at this time. 645 */ 646 pr = pp->acr - cp->acr; 647 pw = pp->acw - cp->acw; 648 pe = pp->ace - cp->ace; 649 650 g_trace(G_T_ACCESS, 651 "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)", 652 dcr, dcw, dce, 653 cp->acr, cp->acw, cp->ace, 654 pp->acr, pp->acw, pp->ace, 655 pp, pp->name); 656 657 /* If foot-shooting is enabled, any open on rank#1 is OK */ 658 if ((g_debugflags & 16) && pp->geom->rank == 1) 659 ; 660 /* If we try exclusive but already write: fail */ 661 else if (dce > 0 && pw > 0) 662 return (EPERM); 663 /* If we try write but already exclusive: fail */ 664 else if (dcw > 0 && pe > 0) 665 return (EPERM); 666 /* If we try to open more but provider is error'ed: fail */ 667 else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0) 668 return (pp->error); 669 670 /* Ok then... */ 671 672 error = pp->geom->access(pp, dcr, dcw, dce); 673 KASSERT(dcr > 0 || dcw > 0 || dce > 0 || error == 0, 674 ("Geom provider %s::%s failed closing ->access()", 675 pp->geom->class->name, pp->name)); 676 if (!error) { 677 /* 678 * If we open first write, spoil any partner consumers. 679 * If we close last write, trigger re-taste. 680 */ 681 if (pp->acw == 0 && dcw != 0) 682 g_spoil(pp, cp); 683 else if (pp->acw != 0 && pp->acw == -dcw && 684 !(pp->geom->flags & G_GEOM_WITHER)) 685 g_post_event(g_new_provider_event, pp, M_WAITOK, 686 pp, NULL); 687 688 pp->acr += dcr; 689 pp->acw += dcw; 690 pp->ace += dce; 691 cp->acr += dcr; 692 cp->acw += dcw; 693 cp->ace += dce; 694 } 695 return (error); 696} 697 698int 699g_handleattr_int(struct bio *bp, const char *attribute, int val) 700{ 701 702 return (g_handleattr(bp, attribute, &val, sizeof val)); 703} 704 705int 706g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val) 707{ 708 709 return (g_handleattr(bp, attribute, &val, sizeof val)); 710} 711 712int 713g_handleattr(struct bio *bp, const char *attribute, void *val, int len) 714{ 715 int error; 716 717 if (strcmp(bp->bio_attribute, attribute)) 718 return (0); 719 if (bp->bio_length != len) { 720 printf("bio_length %jd len %d -> EFAULT\n", 721 (intmax_t)bp->bio_length, len); 722 error = EFAULT; 723 } else { 724 error = 0; 725 bcopy(val, bp->bio_data, len); 726 bp->bio_completed = len; 727 } 728 g_io_deliver(bp, error); 729 return (1); 730} 731 732int 733g_std_access(struct g_provider *pp, 734 int dr __unused, int dw __unused, int de __unused) 735{ 736 737 g_topology_assert(); 738 G_VALID_PROVIDER(pp); 739 return (0); 740} 741 742void 743g_std_done(struct bio *bp) 744{ 745 struct bio *bp2; 746 747 bp2 = bp->bio_parent; 748 if (bp2->bio_error == 0) 749 bp2->bio_error = bp->bio_error; 750 bp2->bio_completed += bp->bio_completed; 751 g_destroy_bio(bp); 752 bp2->bio_inbed++; 753 if (bp2->bio_children == bp2->bio_inbed) 754 g_io_deliver(bp2, bp2->bio_error); 755} 756 757/* XXX: maybe this is only g_slice_spoiled */ 758 759void 760g_std_spoiled(struct g_consumer *cp) 761{ 762 struct g_geom *gp; 763 struct g_provider *pp; 764 765 g_topology_assert(); 766 G_VALID_CONSUMER(cp); 767 g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp); 768 g_detach(cp); 769 gp = cp->geom; 770 LIST_FOREACH(pp, &gp->provider, provider) 771 g_orphan_provider(pp, ENXIO); 772 g_destroy_consumer(cp); 773 if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer)) 774 g_destroy_geom(gp); 775 else 776 gp->flags |= G_GEOM_WITHER; 777} 778 779/* 780 * Spoiling happens when a provider is opened for writing, but consumers 781 * which are configured by in-band data are attached (slicers for instance). 782 * Since the write might potentially change the in-band data, such consumers 783 * need to re-evaluate their existence after the writing session closes. 784 * We do this by (offering to) tear them down when the open for write happens 785 * in return for a re-taste when it closes again. 786 * Together with the fact that such consumers grab an 'e' bit whenever they 787 * are open, regardless of mode, this ends up DTRT. 788 */ 789 790static void 791g_spoil_event(void *arg, int flag) 792{ 793 struct g_provider *pp; 794 struct g_consumer *cp, *cp2; 795 796 g_topology_assert(); 797 if (flag == EV_CANCEL) 798 return; 799 pp = arg; 800 G_VALID_PROVIDER(pp); 801 for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) { 802 cp2 = LIST_NEXT(cp, consumers); 803 if (!cp->spoiled) 804 continue; 805 cp->spoiled = 0; 806 if (cp->geom->spoiled == NULL) 807 continue; 808 cp->geom->spoiled(cp); 809 g_topology_assert(); 810 } 811} 812 813void 814g_spoil(struct g_provider *pp, struct g_consumer *cp) 815{ 816 struct g_consumer *cp2; 817 818 g_topology_assert(); 819 G_VALID_PROVIDER(pp); 820 G_VALID_CONSUMER(cp); 821 822 LIST_FOREACH(cp2, &pp->consumers, consumers) { 823 if (cp2 == cp) 824 continue; 825/* 826 KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr)); 827 KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw)); 828*/ 829 KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace)); 830 cp2->spoiled++; 831 } 832 g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL); 833} 834 835int 836g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len) 837{ 838 int error, i; 839 840 i = len; 841 error = g_io_getattr(attr, cp, &i, var); 842 if (error) 843 return (error); 844 if (i != len) 845 return (EINVAL); 846 return (0); 847} 848 849#ifdef DIAGNOSTIC 850/* 851 * This function walks (topologically unsafely) the mesh and return a 852 * non-zero integer if it finds the argument pointer is an object. 853 * The return value indicates which type of object it is belived to be. 854 * If topology is not locked, this function is potentially dangerous, 855 * but since it is for debugging purposes and can be useful for instance 856 * from DDB, we do not assert topology lock is held. 857 */ 858int 859g_valid_obj(void const *ptr) 860{ 861 struct g_class *mp; 862 struct g_geom *gp; 863 struct g_consumer *cp; 864 struct g_provider *pp; 865 866 LIST_FOREACH(mp, &g_classes, class) { 867 if (ptr == mp) 868 return (1); 869 LIST_FOREACH(gp, &mp->geom, geom) { 870 if (ptr == gp) 871 return (2); 872 LIST_FOREACH(cp, &gp->consumer, consumer) 873 if (ptr == cp) 874 return (3); 875 LIST_FOREACH(pp, &gp->provider, provider) 876 if (ptr == pp) 877 return (4); 878 } 879 } 880 return(0); 881} 882#endif 883