geom_subr.c revision 136797
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 136797 2004-10-22 22:16:24Z arr $"); 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 int post; 64}; 65 66/* 67 * This event offers a new class a chance to taste all preexisting providers. 68 */ 69static void 70g_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 if (hh->post) 86 g_free(hh); 87 else 88 hh->error = 0; 89 g_trace(G_T_TOPOLOGY, "g_load_class(%s)", mp->name); 90 KASSERT(mp->name != NULL && *mp->name != '\0', 91 ("GEOM class has no name")); 92 LIST_FOREACH(mp2, &g_classes, class) { 93 if (mp2 == mp) { 94 printf("The GEOM class %s is already loaded.\n", 95 mp2->name); 96 hh->error = EEXIST; 97 return; 98 } else if (strcmp(mp2->name, mp->name) == 0) { 99 printf("A GEOM class %s is already loaded.\n", 100 mp2->name); 101 hh->error = EEXIST; 102 return; 103 } 104 } 105 106 LIST_INIT(&mp->geom); 107 LIST_INSERT_HEAD(&g_classes, mp, class); 108 if (mp->init != NULL) 109 mp->init(mp); 110 if (mp->taste == NULL) 111 return; 112 LIST_FOREACH(mp2, &g_classes, class) { 113 if (mp == mp2) 114 continue; 115 LIST_FOREACH(gp, &mp2->geom, geom) { 116 LIST_FOREACH(pp, &gp->provider, provider) { 117 mp->taste(mp, pp, 0); 118 g_topology_assert(); 119 } 120 } 121 } 122} 123 124static void 125g_unload_class(void *arg, int flag) 126{ 127 struct g_hh00 *hh; 128 struct g_class *mp; 129 struct g_geom *gp; 130 struct g_provider *pp; 131 struct g_consumer *cp; 132 int error; 133 134 g_topology_assert(); 135 hh = arg; 136 mp = hh->mp; 137 G_VALID_CLASS(mp); 138 g_trace(G_T_TOPOLOGY, "g_unload_class(%s)", mp->name); 139 140 /* 141 * We allow unloading if we have no geoms, or a class 142 * method we can use to get rid of them. 143 */ 144 if (!LIST_EMPTY(&mp->geom) && mp->destroy_geom == NULL) { 145 hh->error = EOPNOTSUPP; 146 return; 147 } 148 149 /* We refuse to unload if anything is open */ 150 LIST_FOREACH(gp, &mp->geom, geom) { 151 LIST_FOREACH(pp, &gp->provider, provider) 152 if (pp->acr || pp->acw || pp->ace) { 153 hh->error = EBUSY; 154 return; 155 } 156 LIST_FOREACH(cp, &gp->consumer, consumer) 157 if (cp->acr || cp->acw || cp->ace) { 158 hh->error = EBUSY; 159 return; 160 } 161 } 162 163 /* Bar new entries */ 164 mp->taste = NULL; 165 mp->config = NULL; 166 167 error = 0; 168 for (;;) { 169 gp = LIST_FIRST(&mp->geom); 170 if (gp == NULL) 171 break; 172 error = mp->destroy_geom(NULL, mp, gp); 173 if (error != 0) 174 break; 175 } 176 if (error == 0) { 177 if (mp->fini != NULL) 178 mp->fini(mp); 179 LIST_REMOVE(mp, class); 180 } 181 hh->error = error; 182 return; 183} 184 185int 186g_modevent(module_t mod, int type, void *data) 187{ 188 struct g_hh00 *hh; 189 int error; 190 static int g_ignition; 191 struct g_class *mp; 192 193 mp = data; 194 if (mp->version != G_VERSION) { 195 printf("GEOM class %s has Wrong version %x\n", 196 mp->name, mp->version); 197 return (EINVAL); 198 } 199 if (!g_ignition) { 200 g_ignition++; 201 g_init(); 202 } 203 hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO); 204 hh->mp = data; 205 error = EOPNOTSUPP; 206 switch (type) { 207 case MOD_LOAD: 208 g_trace(G_T_TOPOLOGY, "g_modevent(%s, LOAD)", hh->mp->name); 209 /* 210 * Once the system is not cold, MOD_LOAD calls will be 211 * from the userland and the g_event thread will be able 212 * to acknowledge their completion. 213 */ 214 if (cold) { 215 hh->post = 1; 216 error = g_post_event(g_load_class, hh, M_WAITOK, NULL); 217 } else { 218 error = g_waitfor_event(g_load_class, hh, M_WAITOK, 219 NULL); 220 if (error == 0) 221 error = hh->error; 222 g_free(hh); 223 } 224 break; 225 case MOD_UNLOAD: 226 g_trace(G_T_TOPOLOGY, "g_modevent(%s, UNLOAD)", hh->mp->name); 227 error = g_waitfor_event(g_unload_class, hh, M_WAITOK, NULL); 228 if (error == 0) 229 error = hh->error; 230 if (error == 0) { 231 g_waitidle(); 232 KASSERT(LIST_EMPTY(&hh->mp->geom), 233 ("Unloaded class (%s) still has geom", hh->mp->name)); 234 } 235 g_free(hh); 236 break; 237 default: 238 g_free(hh); 239 break; 240 } 241 return (error); 242} 243 244struct g_geom * 245g_new_geomf(struct g_class *mp, const char *fmt, ...) 246{ 247 struct g_geom *gp; 248 va_list ap; 249 struct sbuf *sb; 250 251 g_topology_assert(); 252 G_VALID_CLASS(mp); 253 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 254 va_start(ap, fmt); 255 sbuf_vprintf(sb, fmt, ap); 256 va_end(ap); 257 sbuf_finish(sb); 258 gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO); 259 gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO); 260 gp->class = mp; 261 gp->rank = 1; 262 LIST_INIT(&gp->consumer); 263 LIST_INIT(&gp->provider); 264 LIST_INSERT_HEAD(&mp->geom, gp, geom); 265 TAILQ_INSERT_HEAD(&geoms, gp, geoms); 266 strcpy(gp->name, sbuf_data(sb)); 267 sbuf_delete(sb); 268 /* Fill in defaults from class */ 269 gp->start = mp->start; 270 gp->spoiled = mp->spoiled; 271 gp->dumpconf = mp->dumpconf; 272 gp->access = mp->access; 273 gp->orphan = mp->orphan; 274 gp->ioctl = mp->ioctl; 275 return (gp); 276} 277 278void 279g_destroy_geom(struct g_geom *gp) 280{ 281 282 g_topology_assert(); 283 G_VALID_GEOM(gp); 284 g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name); 285 KASSERT(LIST_EMPTY(&gp->consumer), 286 ("g_destroy_geom(%s) with consumer(s) [%p]", 287 gp->name, LIST_FIRST(&gp->consumer))); 288 KASSERT(LIST_EMPTY(&gp->provider), 289 ("g_destroy_geom(%s) with provider(s) [%p]", 290 gp->name, LIST_FIRST(&gp->provider))); 291 g_cancel_event(gp); 292 LIST_REMOVE(gp, geom); 293 TAILQ_REMOVE(&geoms, gp, geoms); 294 g_free(gp->name); 295 g_free(gp); 296} 297 298/* 299 * This function is called (repeatedly) until the has withered away. 300 */ 301void 302g_wither_geom(struct g_geom *gp, int error) 303{ 304 struct g_provider *pp; 305 306 g_topology_assert(); 307 G_VALID_GEOM(gp); 308 g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name); 309 if (!(gp->flags & G_GEOM_WITHER)) { 310 gp->flags |= G_GEOM_WITHER; 311 LIST_FOREACH(pp, &gp->provider, provider) 312 if (!(pp->flags & G_PF_ORPHAN)) 313 g_orphan_provider(pp, error); 314 } 315 g_do_wither(); 316} 317 318/* 319 * This function is called (repeatedly) until we cant wash away more 320 * withered bits at present. Return value contains two bits. Bit 0 321 * set means "withering stuff we can't wash now", bit 1 means "call 322 * me again, there may be stuff I didn't get the first time around. 323 */ 324int 325g_wither_washer() 326{ 327 struct g_class *mp; 328 struct g_geom *gp, *gp2; 329 struct g_provider *pp, *pp2; 330 struct g_consumer *cp, *cp2; 331 int result; 332 333 result = 0; 334 g_topology_assert(); 335 LIST_FOREACH(mp, &g_classes, class) { 336 LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) { 337 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) { 338 if (!(pp->flags & G_PF_WITHER)) 339 continue; 340 if (LIST_EMPTY(&pp->consumers)) 341 g_destroy_provider(pp); 342 else 343 result |= 1; 344 } 345 if (!(gp->flags & G_GEOM_WITHER)) 346 continue; 347 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) { 348 if (LIST_EMPTY(&pp->consumers)) 349 g_destroy_provider(pp); 350 else 351 result |= 1; 352 } 353 LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp2) { 354 if (cp->acr || cp->acw || cp->ace) { 355 result |= 1; 356 continue; 357 } 358 if (cp->provider != NULL) 359 g_detach(cp); 360 g_destroy_consumer(cp); 361 result |= 2; 362 } 363 if (LIST_EMPTY(&gp->provider) && 364 LIST_EMPTY(&gp->consumer)) 365 g_destroy_geom(gp); 366 else 367 result |= 1; 368 } 369 } 370 return (result); 371} 372 373struct g_consumer * 374g_new_consumer(struct g_geom *gp) 375{ 376 struct g_consumer *cp; 377 378 g_topology_assert(); 379 G_VALID_GEOM(gp); 380 KASSERT(!(gp->flags & G_GEOM_WITHER), 381 ("g_new_consumer on WITHERing geom(%s) (class %s)", 382 gp->name, gp->class->name)); 383 KASSERT(gp->orphan != NULL, 384 ("g_new_consumer on geom(%s) (class %s) without orphan", 385 gp->name, gp->class->name)); 386 387 cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO); 388 cp->geom = gp; 389 cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED, 390 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX); 391 LIST_INSERT_HEAD(&gp->consumer, cp, consumer); 392 return(cp); 393} 394 395void 396g_destroy_consumer(struct g_consumer *cp) 397{ 398 struct g_geom *gp; 399 400 g_topology_assert(); 401 G_VALID_CONSUMER(cp); 402 g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp); 403 KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached")); 404 KASSERT (cp->acr == 0, ("g_destroy_consumer with acr")); 405 KASSERT (cp->acw == 0, ("g_destroy_consumer with acw")); 406 KASSERT (cp->ace == 0, ("g_destroy_consumer with ace")); 407 g_cancel_event(cp); 408 gp = cp->geom; 409 LIST_REMOVE(cp, consumer); 410 devstat_remove_entry(cp->stat); 411 g_free(cp); 412 if (gp->flags & G_GEOM_WITHER) 413 g_do_wither(); 414} 415 416static void 417g_new_provider_event(void *arg, int flag) 418{ 419 struct g_class *mp; 420 struct g_provider *pp; 421 struct g_consumer *cp; 422 int i; 423 424 g_topology_assert(); 425 if (flag == EV_CANCEL) 426 return; 427 if (g_shutdown) 428 return; 429 pp = arg; 430 G_VALID_PROVIDER(pp); 431 LIST_FOREACH(mp, &g_classes, class) { 432 if (mp->taste == NULL) 433 continue; 434 i = 1; 435 LIST_FOREACH(cp, &pp->consumers, consumers) 436 if (cp->geom->class == mp) 437 i = 0; 438 if (!i) 439 continue; 440 mp->taste(mp, pp, 0); 441 g_topology_assert(); 442 } 443} 444 445 446struct g_provider * 447g_new_providerf(struct g_geom *gp, const char *fmt, ...) 448{ 449 struct g_provider *pp; 450 struct sbuf *sb; 451 va_list ap; 452 453 g_topology_assert(); 454 G_VALID_GEOM(gp); 455 KASSERT(gp->access != NULL, 456 ("new provider on geom(%s) without ->access (class %s)", 457 gp->name, gp->class->name)); 458 KASSERT(gp->start != NULL, 459 ("new provider on geom(%s) without ->start (class %s)", 460 gp->name, gp->class->name)); 461 KASSERT(!(gp->flags & G_GEOM_WITHER), 462 ("new provider on WITHERing geom(%s) (class %s)", 463 gp->name, gp->class->name)); 464 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 465 va_start(ap, fmt); 466 sbuf_vprintf(sb, fmt, ap); 467 va_end(ap); 468 sbuf_finish(sb); 469 pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO); 470 pp->name = (char *)(pp + 1); 471 strcpy(pp->name, sbuf_data(sb)); 472 sbuf_delete(sb); 473 LIST_INIT(&pp->consumers); 474 pp->error = ENXIO; 475 pp->geom = gp; 476 pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED, 477 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX); 478 LIST_INSERT_HEAD(&gp->provider, pp, provider); 479 g_post_event(g_new_provider_event, pp, M_WAITOK, pp, gp, NULL); 480 return (pp); 481} 482 483void 484g_error_provider(struct g_provider *pp, int error) 485{ 486 487 /* G_VALID_PROVIDER(pp); We may not have g_topology */ 488 pp->error = error; 489} 490 491struct g_provider * 492g_provider_by_name(char const *arg) 493{ 494 struct g_class *cp; 495 struct g_geom *gp; 496 struct g_provider *pp; 497 498 LIST_FOREACH(cp, &g_classes, class) { 499 LIST_FOREACH(gp, &cp->geom, geom) { 500 LIST_FOREACH(pp, &gp->provider, provider) { 501 if (!strcmp(arg, pp->name)) 502 return (pp); 503 } 504 } 505 } 506 return (NULL); 507} 508 509void 510g_destroy_provider(struct g_provider *pp) 511{ 512 struct g_geom *gp; 513 514 g_topology_assert(); 515 G_VALID_PROVIDER(pp); 516 KASSERT(LIST_EMPTY(&pp->consumers), 517 ("g_destroy_provider but attached")); 518 KASSERT (pp->acr == 0, ("g_destroy_provider with acr")); 519 KASSERT (pp->acw == 0, ("g_destroy_provider with acw")); 520 KASSERT (pp->acw == 0, ("g_destroy_provider with ace")); 521 g_cancel_event(pp); 522 LIST_REMOVE(pp, provider); 523 gp = pp->geom; 524 devstat_remove_entry(pp->stat); 525 g_free(pp); 526 if ((gp->flags & G_GEOM_WITHER)) 527 g_do_wither(); 528} 529 530/* 531 * We keep the "geoms" list sorted by topological order (== increasing 532 * numerical rank) at all times. 533 * When an attach is done, the attaching geoms rank is invalidated 534 * and it is moved to the tail of the list. 535 * All geoms later in the sequence has their ranks reevaluated in 536 * sequence. If we cannot assign rank to a geom because it's 537 * prerequisites do not have rank, we move that element to the tail 538 * of the sequence with invalid rank as well. 539 * At some point we encounter our original geom and if we stil fail 540 * to assign it a rank, there must be a loop and we fail back to 541 * g_attach() which detach again and calls redo_rank again 542 * to fix up the damage. 543 * It would be much simpler code wise to do it recursively, but we 544 * can't risk that on the kernel stack. 545 */ 546 547static int 548redo_rank(struct g_geom *gp) 549{ 550 struct g_consumer *cp; 551 struct g_geom *gp1, *gp2; 552 int n, m; 553 554 g_topology_assert(); 555 G_VALID_GEOM(gp); 556 557 /* Invalidate this geoms rank and move it to the tail */ 558 gp1 = TAILQ_NEXT(gp, geoms); 559 if (gp1 != NULL) { 560 gp->rank = 0; 561 TAILQ_REMOVE(&geoms, gp, geoms); 562 TAILQ_INSERT_TAIL(&geoms, gp, geoms); 563 } else { 564 gp1 = gp; 565 } 566 567 /* re-rank the rest of the sequence */ 568 for (; gp1 != NULL; gp1 = gp2) { 569 gp1->rank = 0; 570 m = 1; 571 LIST_FOREACH(cp, &gp1->consumer, consumer) { 572 if (cp->provider == NULL) 573 continue; 574 n = cp->provider->geom->rank; 575 if (n == 0) { 576 m = 0; 577 break; 578 } else if (n >= m) 579 m = n + 1; 580 } 581 gp1->rank = m; 582 gp2 = TAILQ_NEXT(gp1, geoms); 583 584 /* got a rank, moving on */ 585 if (m != 0) 586 continue; 587 588 /* no rank to original geom means loop */ 589 if (gp == gp1) 590 return (ELOOP); 591 592 /* no rank, put it at the end move on */ 593 TAILQ_REMOVE(&geoms, gp1, geoms); 594 TAILQ_INSERT_TAIL(&geoms, gp1, geoms); 595 } 596 return (0); 597} 598 599int 600g_attach(struct g_consumer *cp, struct g_provider *pp) 601{ 602 int error; 603 604 g_topology_assert(); 605 G_VALID_CONSUMER(cp); 606 G_VALID_PROVIDER(pp); 607 KASSERT(cp->provider == NULL, ("attach but attached")); 608 cp->provider = pp; 609 LIST_INSERT_HEAD(&pp->consumers, cp, consumers); 610 error = redo_rank(cp->geom); 611 if (error) { 612 LIST_REMOVE(cp, consumers); 613 cp->provider = NULL; 614 redo_rank(cp->geom); 615 } 616 return (error); 617} 618 619void 620g_detach(struct g_consumer *cp) 621{ 622 struct g_provider *pp; 623 624 g_topology_assert(); 625 G_VALID_CONSUMER(cp); 626 g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp); 627 KASSERT(cp->provider != NULL, ("detach but not attached")); 628 KASSERT(cp->acr == 0, ("detach but nonzero acr")); 629 KASSERT(cp->acw == 0, ("detach but nonzero acw")); 630 KASSERT(cp->ace == 0, ("detach but nonzero ace")); 631 KASSERT(cp->nstart == cp->nend, 632 ("detach with active requests")); 633 pp = cp->provider; 634 LIST_REMOVE(cp, consumers); 635 cp->provider = NULL; 636 if (pp->geom->flags & G_GEOM_WITHER) 637 g_do_wither(); 638 else if (pp->flags & G_PF_WITHER) 639 g_do_wither(); 640 redo_rank(cp->geom); 641} 642 643/* 644 * g_access() 645 * 646 * Access-check with delta values. The question asked is "can provider 647 * "cp" change the access counters by the relative amounts dc[rwe] ?" 648 */ 649 650int 651g_access(struct g_consumer *cp, int dcr, int dcw, int dce) 652{ 653 struct g_provider *pp; 654 int pr,pw,pe; 655 int error; 656 657 g_topology_assert(); 658 G_VALID_CONSUMER(cp); 659 pp = cp->provider; 660 KASSERT(pp != NULL, ("access but not attached")); 661 G_VALID_PROVIDER(pp); 662 663 g_trace(G_T_ACCESS, "g_access(%p(%s), %d, %d, %d)", 664 cp, pp->name, dcr, dcw, dce); 665 666 KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr")); 667 KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw")); 668 KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace")); 669 KASSERT(dcr != 0 || dcw != 0 || dce != 0, ("NOP access request")); 670 KASSERT(pp->geom->access != NULL, ("NULL geom->access")); 671 672 /* 673 * If our class cares about being spoiled, and we have been, we 674 * are probably just ahead of the event telling us that. Fail 675 * now rather than having to unravel this later. 676 */ 677 if (cp->geom->spoiled != NULL && cp->spoiled && 678 (dcr > 0 || dcw > 0 || dce > 0)) 679 return (ENXIO); 680 681 /* 682 * Figure out what counts the provider would have had, if this 683 * consumer had (r0w0e0) at this time. 684 */ 685 pr = pp->acr - cp->acr; 686 pw = pp->acw - cp->acw; 687 pe = pp->ace - cp->ace; 688 689 g_trace(G_T_ACCESS, 690 "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)", 691 dcr, dcw, dce, 692 cp->acr, cp->acw, cp->ace, 693 pp->acr, pp->acw, pp->ace, 694 pp, pp->name); 695 696 /* If foot-shooting is enabled, any open on rank#1 is OK */ 697 if ((g_debugflags & 16) && pp->geom->rank == 1) 698 ; 699 /* If we try exclusive but already write: fail */ 700 else if (dce > 0 && pw > 0) 701 return (EPERM); 702 /* If we try write but already exclusive: fail */ 703 else if (dcw > 0 && pe > 0) 704 return (EPERM); 705 /* If we try to open more but provider is error'ed: fail */ 706 else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0) 707 return (pp->error); 708 709 /* Ok then... */ 710 711 error = pp->geom->access(pp, dcr, dcw, dce); 712 KASSERT(dcr > 0 || dcw > 0 || dce > 0 || error == 0, 713 ("Geom provider %s::%s failed closing ->access()", 714 pp->geom->class->name, pp->name)); 715 if (!error) { 716 /* 717 * If we open first write, spoil any partner consumers. 718 * If we close last write, trigger re-taste. 719 */ 720 if (pp->acw == 0 && dcw != 0) 721 g_spoil(pp, cp); 722 else if (pp->acw != 0 && pp->acw == -dcw && 723 !(pp->geom->flags & G_GEOM_WITHER)) 724 g_post_event(g_new_provider_event, pp, M_WAITOK, 725 pp, NULL); 726 727 pp->acr += dcr; 728 pp->acw += dcw; 729 pp->ace += dce; 730 cp->acr += dcr; 731 cp->acw += dcw; 732 cp->ace += dce; 733 if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0) 734 KASSERT(pp->sectorsize > 0, 735 ("Provider %s lacks sectorsize", pp->name)); 736 } 737 return (error); 738} 739 740int 741g_handleattr_int(struct bio *bp, const char *attribute, int val) 742{ 743 744 return (g_handleattr(bp, attribute, &val, sizeof val)); 745} 746 747int 748g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val) 749{ 750 751 return (g_handleattr(bp, attribute, &val, sizeof val)); 752} 753 754int 755g_handleattr(struct bio *bp, const char *attribute, void *val, int len) 756{ 757 int error; 758 759 if (strcmp(bp->bio_attribute, attribute)) 760 return (0); 761 if (bp->bio_length != len) { 762 printf("bio_length %jd len %d -> EFAULT\n", 763 (intmax_t)bp->bio_length, len); 764 error = EFAULT; 765 } else { 766 error = 0; 767 bcopy(val, bp->bio_data, len); 768 bp->bio_completed = len; 769 } 770 g_io_deliver(bp, error); 771 return (1); 772} 773 774int 775g_std_access(struct g_provider *pp, 776 int dr __unused, int dw __unused, int de __unused) 777{ 778 779 g_topology_assert(); 780 G_VALID_PROVIDER(pp); 781 return (0); 782} 783 784void 785g_std_done(struct bio *bp) 786{ 787 struct bio *bp2; 788 789 bp2 = bp->bio_parent; 790 if (bp2->bio_error == 0) 791 bp2->bio_error = bp->bio_error; 792 bp2->bio_completed += bp->bio_completed; 793 g_destroy_bio(bp); 794 bp2->bio_inbed++; 795 if (bp2->bio_children == bp2->bio_inbed) 796 g_io_deliver(bp2, bp2->bio_error); 797} 798 799/* XXX: maybe this is only g_slice_spoiled */ 800 801void 802g_std_spoiled(struct g_consumer *cp) 803{ 804 struct g_geom *gp; 805 struct g_provider *pp; 806 807 g_topology_assert(); 808 G_VALID_CONSUMER(cp); 809 g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp); 810 g_detach(cp); 811 gp = cp->geom; 812 LIST_FOREACH(pp, &gp->provider, provider) 813 g_orphan_provider(pp, ENXIO); 814 g_destroy_consumer(cp); 815 if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer)) 816 g_destroy_geom(gp); 817 else 818 gp->flags |= G_GEOM_WITHER; 819} 820 821/* 822 * Spoiling happens when a provider is opened for writing, but consumers 823 * which are configured by in-band data are attached (slicers for instance). 824 * Since the write might potentially change the in-band data, such consumers 825 * need to re-evaluate their existence after the writing session closes. 826 * We do this by (offering to) tear them down when the open for write happens 827 * in return for a re-taste when it closes again. 828 * Together with the fact that such consumers grab an 'e' bit whenever they 829 * are open, regardless of mode, this ends up DTRT. 830 */ 831 832static void 833g_spoil_event(void *arg, int flag) 834{ 835 struct g_provider *pp; 836 struct g_consumer *cp, *cp2; 837 838 g_topology_assert(); 839 if (flag == EV_CANCEL) 840 return; 841 pp = arg; 842 G_VALID_PROVIDER(pp); 843 for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) { 844 cp2 = LIST_NEXT(cp, consumers); 845 if (!cp->spoiled) 846 continue; 847 cp->spoiled = 0; 848 if (cp->geom->spoiled == NULL) 849 continue; 850 cp->geom->spoiled(cp); 851 g_topology_assert(); 852 } 853} 854 855void 856g_spoil(struct g_provider *pp, struct g_consumer *cp) 857{ 858 struct g_consumer *cp2; 859 860 g_topology_assert(); 861 G_VALID_PROVIDER(pp); 862 G_VALID_CONSUMER(cp); 863 864 LIST_FOREACH(cp2, &pp->consumers, consumers) { 865 if (cp2 == cp) 866 continue; 867/* 868 KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr)); 869 KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw)); 870*/ 871 KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace)); 872 cp2->spoiled++; 873 } 874 g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL); 875} 876 877int 878g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len) 879{ 880 int error, i; 881 882 i = len; 883 error = g_io_getattr(attr, cp, &i, var); 884 if (error) 885 return (error); 886 if (i != len) 887 return (EINVAL); 888 return (0); 889} 890 891#ifdef DIAGNOSTIC 892/* 893 * This function walks (topologically unsafely) the mesh and return a 894 * non-zero integer if it finds the argument pointer is an object. 895 * The return value indicates which type of object it is belived to be. 896 * If topology is not locked, this function is potentially dangerous, 897 * but since it is for debugging purposes and can be useful for instance 898 * from DDB, we do not assert topology lock is held. 899 */ 900int 901g_valid_obj(void const *ptr) 902{ 903 struct g_class *mp; 904 struct g_geom *gp; 905 struct g_consumer *cp; 906 struct g_provider *pp; 907 908 LIST_FOREACH(mp, &g_classes, class) { 909 if (ptr == mp) 910 return (1); 911 LIST_FOREACH(gp, &mp->geom, geom) { 912 if (ptr == gp) 913 return (2); 914 LIST_FOREACH(cp, &gp->consumer, consumer) 915 if (ptr == cp) 916 return (3); 917 LIST_FOREACH(pp, &gp->provider, provider) 918 if (ptr == pp) 919 return (4); 920 } 921 } 922 return(0); 923} 924#endif 925