geom_subr.c revision 133316
1232950Stheraven/*- 2232950Stheraven * Copyright (c) 2002 Poul-Henning Kamp 3232950Stheraven * Copyright (c) 2002 Networks Associates Technology, Inc. 4232950Stheraven * All rights reserved. 5232950Stheraven * 6232950Stheraven * This software was developed for the FreeBSD Project by Poul-Henning Kamp 7232950Stheraven * and NAI Labs, the Security Research Division of Network Associates, Inc. 8232950Stheraven * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 9232950Stheraven * DARPA CHATS research program. 10232950Stheraven * 11232950Stheraven * Redistribution and use in source and binary forms, with or without 12232950Stheraven * modification, are permitted provided that the following conditions 13232950Stheraven * are met: 14232950Stheraven * 1. Redistributions of source code must retain the above copyright 15232950Stheraven * notice, this list of conditions and the following disclaimer. 16232950Stheraven * 2. Redistributions in binary form must reproduce the above copyright 17232950Stheraven * notice, this list of conditions and the following disclaimer in the 18232950Stheraven * documentation and/or other materials provided with the distribution. 19232950Stheraven * 3. The names of the authors may not be used to endorse or promote 20232950Stheraven * products derived from this software without specific prior written 21232950Stheraven * permission. 22232950Stheraven * 23232950Stheraven * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 24232950Stheraven * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25232950Stheraven * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26232950Stheraven * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 27227825Stheraven * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28227825Stheraven * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29227825Stheraven * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30227825Stheraven * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31227825Stheraven * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32233235Stheraven * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33233235Stheraven * SUCH DAMAGE. 34233235Stheraven */ 35233235Stheraven 36227825Stheraven#include <sys/cdefs.h> 37233235Stheraven__FBSDID("$FreeBSD: head/sys/geom/geom_subr.c 133316 2004-08-08 07:30:47Z phk $"); 38233235Stheraven 39233235Stheraven#include <sys/param.h> 40233235Stheraven#include <sys/systm.h> 41233235Stheraven#include <sys/devicestat.h> 42233235Stheraven#include <sys/kernel.h> 43233235Stheraven#include <sys/malloc.h> 44233235Stheraven#include <sys/bio.h> 45233235Stheraven#include <sys/sysctl.h> 46233235Stheraven#include <sys/proc.h> 47233235Stheraven#include <sys/kthread.h> 48233235Stheraven#include <sys/lock.h> 49233235Stheraven#include <sys/mutex.h> 50233235Stheraven#include <sys/errno.h> 51233235Stheraven#include <sys/sbuf.h> 52233235Stheraven#include <geom/geom.h> 53233235Stheraven#include <geom/geom_int.h> 54233235Stheraven#include <machine/stdarg.h> 55233235Stheraven 56233235Stheravenstruct class_list_head g_classes = LIST_HEAD_INITIALIZER(g_classes); 57233235Stheravenstatic struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms); 58233235Stheravenchar *g_wait_event, *g_wait_up, *g_wait_down, *g_wait_sim; 59233235Stheraven 60233235Stheravenstruct g_hh00 { 61233235Stheraven struct g_class *mp; 62233235Stheraven int error; 63233235Stheraven}; 64233235Stheraven 65233235Stheraven/* 66233235Stheraven * This event offers a new class a chance to taste all preexisting providers. 67233235Stheraven */ 68233235Stheravenstatic void 69233235Stheraveng_load_class(void *arg, int flag) 70233235Stheraven{ 71233235Stheraven struct g_hh00 *hh; 72233235Stheraven struct g_class *mp2, *mp; 73233235Stheraven struct g_geom *gp; 74233235Stheraven struct g_provider *pp; 75233235Stheraven 76233235Stheraven g_topology_assert(); 77233235Stheraven if (flag == EV_CANCEL) /* XXX: can't happen ? */ 78233235Stheraven return; 79233235Stheraven if (g_shutdown) 80233235Stheraven return; 81233235Stheraven 82233235Stheraven hh = arg; 83233235Stheraven mp = hh->mp; 84233235Stheraven g_free(hh); 85233235Stheraven g_trace(G_T_TOPOLOGY, "g_load_class(%s)", mp->name); 86233235Stheraven KASSERT(mp->name != NULL && *mp->name != '\0', 87233235Stheraven ("GEOM class has no name")); 88233235Stheraven LIST_FOREACH(mp2, &g_classes, class) { 89233235Stheraven KASSERT(mp2 != mp, 90233235Stheraven ("The GEOM class %s already loaded", mp2->name)); 91233235Stheraven KASSERT(strcmp(mp2->name, mp->name) != 0, 92233235Stheraven ("A GEOM class named %s is already loaded", mp2->name)); 93233235Stheraven } 94233235Stheraven 95233235Stheraven LIST_INIT(&mp->geom); 96233235Stheraven LIST_INSERT_HEAD(&g_classes, mp, class); 97233235Stheraven if (mp->init != NULL) 98233235Stheraven mp->init(mp); 99233235Stheraven if (mp->taste == NULL) 100233235Stheraven return; 101233235Stheraven LIST_FOREACH(mp2, &g_classes, class) { 102233235Stheraven if (mp == mp2) 103233235Stheraven continue; 104233235Stheraven LIST_FOREACH(gp, &mp2->geom, geom) { 105233235Stheraven LIST_FOREACH(pp, &gp->provider, provider) { 106233235Stheraven mp->taste(mp, pp, 0); 107233235Stheraven g_topology_assert(); 108233235Stheraven } 109233235Stheraven } 110233235Stheraven } 111233235Stheraven} 112233235Stheraven 113227825Stheravenstatic void 114227825Stheraveng_unload_class(void *arg, int flag) 115227825Stheraven{ 116227825Stheraven struct g_hh00 *hh; 117227825Stheraven struct g_class *mp; 118227825Stheraven struct g_geom *gp; 119227825Stheraven struct g_provider *pp; 120227825Stheraven struct g_consumer *cp; 121227825Stheraven int error; 122227825Stheraven 123227825Stheraven g_topology_assert(); 124227825Stheraven hh = arg; 125227825Stheraven mp = hh->mp; 126227825Stheraven G_VALID_CLASS(mp); 127227825Stheraven g_trace(G_T_TOPOLOGY, "g_unload_class(%s)", mp->name); 128227825Stheraven 129227825Stheraven /* 130227825Stheraven * We allow unloading if we have no geoms, or a class 131227825Stheraven * method we can use to get rid of them. 132233235Stheraven */ 133227825Stheraven if (!LIST_EMPTY(&mp->geom) && mp->destroy_geom == NULL) { 134227825Stheraven hh->error = EOPNOTSUPP; 135227825Stheraven return; 136227825Stheraven } 137227825Stheraven 138227825Stheraven /* We refuse to unload if anything is open */ 139227825Stheraven LIST_FOREACH(gp, &mp->geom, geom) { 140227825Stheraven LIST_FOREACH(pp, &gp->provider, provider) 141227825Stheraven if (pp->acr || pp->acw || pp->ace) { 142227825Stheraven hh->error = EBUSY; 143227825Stheraven return; 144227825Stheraven } 145227825Stheraven LIST_FOREACH(cp, &gp->consumer, consumer) 146227825Stheraven if (cp->acr || cp->acw || cp->ace) { 147227825Stheraven hh->error = EBUSY; 148227825Stheraven return; 149227825Stheraven } 150227825Stheraven } 151233235Stheraven 152233235Stheraven /* Bar new entries */ 153233235Stheraven mp->taste = NULL; 154233235Stheraven mp->config = NULL; 155233235Stheraven 156233235Stheraven error = 0; 157227825Stheraven for (;;) { 158227825Stheraven gp = LIST_FIRST(&mp->geom); 159227825Stheraven if (gp == NULL) 160227825Stheraven break; 161227825Stheraven error = mp->destroy_geom(NULL, mp, gp); 162227825Stheraven if (error != 0) 163227825Stheraven break; 164227825Stheraven } 165227825Stheraven if (error == 0) { 166227825Stheraven if (mp->fini != NULL) 167233235Stheraven mp->fini(mp); 168233235Stheraven LIST_REMOVE(mp, class); 169233235Stheraven } 170227825Stheraven hh->error = error; 171227825Stheraven return; 172227825Stheraven} 173227825Stheraven 174227825Stheravenint 175227825Stheraveng_modevent(module_t mod, int type, void *data) 176227825Stheraven{ 177227825Stheraven struct g_hh00 *hh; 178227825Stheraven int error; 179227825Stheraven static int g_ignition; 180227825Stheraven struct g_class *mp; 181227825Stheraven 182227825Stheraven mp = data; 183227825Stheraven if (mp->version != 0 && mp->version != G_VERSION) { 184227825Stheraven printf("GEOM class %s has Wrong version %x\n", 185227825Stheraven mp->name, mp->version); 186227825Stheraven return (EINVAL); 187227825Stheraven } 188227825Stheraven if (!g_ignition) { 189227825Stheraven g_ignition++; 190227825Stheraven g_init(); 191227825Stheraven } 192227825Stheraven hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO); 193227825Stheraven hh->mp = data; 194227825Stheraven error = EOPNOTSUPP; 195227825Stheraven switch (type) { 196227825Stheraven case MOD_LOAD: 197227825Stheraven g_trace(G_T_TOPOLOGY, "g_modevent(%s, LOAD)", hh->mp->name); 198227825Stheraven g_post_event(g_load_class, hh, M_WAITOK, NULL); 199227825Stheraven error = 0; 200227825Stheraven break; 201227825Stheraven case MOD_UNLOAD: 202227825Stheraven g_trace(G_T_TOPOLOGY, "g_modevent(%s, UNLOAD)", hh->mp->name); 203227825Stheraven error = g_waitfor_event(g_unload_class, hh, M_WAITOK, NULL); 204227825Stheraven if (error == 0) 205227825Stheraven error = hh->error; 206227825Stheraven if (error == 0) { 207227825Stheraven g_waitidle(); 208227825Stheraven KASSERT(LIST_EMPTY(&hh->mp->geom), 209227825Stheraven ("Unloaded class (%s) still has geom", hh->mp->name)); 210227825Stheraven } 211227825Stheraven g_free(hh); 212227825Stheraven break; 213227825Stheraven default: 214227825Stheraven g_free(hh); 215227825Stheraven break; 216227825Stheraven } 217227825Stheraven return (error); 218227825Stheraven} 219227825Stheraven 220227825Stheravenstruct g_geom * 221227825Stheraveng_new_geomf(struct g_class *mp, const char *fmt, ...) 222227825Stheraven{ 223227825Stheraven struct g_geom *gp; 224227825Stheraven va_list ap; 225227825Stheraven struct sbuf *sb; 226227825Stheraven 227227825Stheraven g_topology_assert(); 228227825Stheraven G_VALID_CLASS(mp); 229227825Stheraven sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 230227825Stheraven va_start(ap, fmt); 231227825Stheraven sbuf_vprintf(sb, fmt, ap); 232227825Stheraven va_end(ap); 233227825Stheraven sbuf_finish(sb); 234227825Stheraven gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO); 235227825Stheraven gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO); 236227825Stheraven gp->class = mp; 237227825Stheraven gp->rank = 1; 238227825Stheraven LIST_INIT(&gp->consumer); 239227825Stheraven LIST_INIT(&gp->provider); 240227825Stheraven LIST_INSERT_HEAD(&mp->geom, gp, geom); 241227825Stheraven TAILQ_INSERT_HEAD(&geoms, gp, geoms); 242227825Stheraven strcpy(gp->name, sbuf_data(sb)); 243227825Stheraven sbuf_delete(sb); 244227825Stheraven /* Fill in defaults from class */ 245227825Stheraven gp->start = mp->start; 246227825Stheraven gp->spoiled = mp->spoiled; 247227825Stheraven gp->dumpconf = mp->dumpconf; 248227825Stheraven gp->access = mp->access; 249227825Stheraven gp->orphan = mp->orphan; 250233235Stheraven gp->ioctl = mp->ioctl; 251233235Stheraven return (gp); 252233235Stheraven} 253227825Stheraven 254227825Stheravenvoid 255227825Stheraveng_destroy_geom(struct g_geom *gp) 256227825Stheraven{ 257227825Stheraven 258227825Stheraven g_topology_assert(); 259227825Stheraven G_VALID_GEOM(gp); 260227825Stheraven g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name); 261227825Stheraven KASSERT(LIST_EMPTY(&gp->consumer), 262227825Stheraven ("g_destroy_geom(%s) with consumer(s) [%p]", 263227825Stheraven gp->name, LIST_FIRST(&gp->consumer))); 264227825Stheraven KASSERT(LIST_EMPTY(&gp->provider), 265227825Stheraven ("g_destroy_geom(%s) with provider(s) [%p]", 266227825Stheraven gp->name, LIST_FIRST(&gp->provider))); 267227825Stheraven g_cancel_event(gp); 268227825Stheraven LIST_REMOVE(gp, geom); 269227825Stheraven TAILQ_REMOVE(&geoms, gp, geoms); 270227825Stheraven g_free(gp->name); 271227825Stheraven g_free(gp); 272227825Stheraven} 273227825Stheraven 274227825Stheraven/* 275227825Stheraven * This function is called (repeatedly) until the has withered away. 276227825Stheraven */ 277227825Stheravenvoid 278227825Stheraveng_wither_geom(struct g_geom *gp, int error) 279227825Stheraven{ 280227825Stheraven struct g_provider *pp; 281227825Stheraven 282227825Stheraven g_topology_assert(); 283227825Stheraven G_VALID_GEOM(gp); 284227825Stheraven g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name); 285227825Stheraven if (!(gp->flags & G_GEOM_WITHER)) { 286227825Stheraven gp->flags |= G_GEOM_WITHER; 287233235Stheraven LIST_FOREACH(pp, &gp->provider, provider) 288233235Stheraven if (!(pp->flags & G_PF_ORPHAN)) 289233235Stheraven g_orphan_provider(pp, error); 290233235Stheraven } 291227825Stheraven g_do_wither(); 292227825Stheraven} 293227825Stheraven 294227825Stheraven/* 295227825Stheraven * This function is called (repeatedly) until we cant wash away more 296227825Stheraven * withered bits at present. Return value contains two bits. Bit 0 297227825Stheraven * set means "withering stuff we can't wash now", bit 1 means "call 298227825Stheraven * me again, there may be stuff I didn't get the first time around. 299227825Stheraven */ 300227825Stheravenint 301227825Stheraveng_wither_washer() 302227825Stheraven{ 303227825Stheraven struct g_class *mp; 304227825Stheraven struct g_geom *gp, *gp2; 305227825Stheraven struct g_provider *pp, *pp2; 306227825Stheraven struct g_consumer *cp, *cp2; 307227825Stheraven int result; 308227825Stheraven 309227825Stheraven result = 0; 310227825Stheraven g_topology_assert(); 311227825Stheraven LIST_FOREACH(mp, &g_classes, class) { 312227825Stheraven LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) { 313227825Stheraven 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 349struct g_consumer * 350g_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 371void 372g_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 392static void 393g_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 422struct g_provider * 423g_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 459void 460g_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 467struct g_provider * 468g_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 485void 486g_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 523static int 524redo_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 575int 576g_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 595void 596g_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 626int 627g_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 } 710 return (error); 711} 712 713int 714g_handleattr_int(struct bio *bp, const char *attribute, int val) 715{ 716 717 return (g_handleattr(bp, attribute, &val, sizeof val)); 718} 719 720int 721g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val) 722{ 723 724 return (g_handleattr(bp, attribute, &val, sizeof val)); 725} 726 727int 728g_handleattr(struct bio *bp, const char *attribute, void *val, int len) 729{ 730 int error; 731 732 if (strcmp(bp->bio_attribute, attribute)) 733 return (0); 734 if (bp->bio_length != len) { 735 printf("bio_length %jd len %d -> EFAULT\n", 736 (intmax_t)bp->bio_length, len); 737 error = EFAULT; 738 } else { 739 error = 0; 740 bcopy(val, bp->bio_data, len); 741 bp->bio_completed = len; 742 } 743 g_io_deliver(bp, error); 744 return (1); 745} 746 747int 748g_std_access(struct g_provider *pp, 749 int dr __unused, int dw __unused, int de __unused) 750{ 751 752 g_topology_assert(); 753 G_VALID_PROVIDER(pp); 754 return (0); 755} 756 757void 758g_std_done(struct bio *bp) 759{ 760 struct bio *bp2; 761 762 bp2 = bp->bio_parent; 763 if (bp2->bio_error == 0) 764 bp2->bio_error = bp->bio_error; 765 bp2->bio_completed += bp->bio_completed; 766 g_destroy_bio(bp); 767 bp2->bio_inbed++; 768 if (bp2->bio_children == bp2->bio_inbed) 769 g_io_deliver(bp2, bp2->bio_error); 770} 771 772/* XXX: maybe this is only g_slice_spoiled */ 773 774void 775g_std_spoiled(struct g_consumer *cp) 776{ 777 struct g_geom *gp; 778 struct g_provider *pp; 779 780 g_topology_assert(); 781 G_VALID_CONSUMER(cp); 782 g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp); 783 g_detach(cp); 784 gp = cp->geom; 785 LIST_FOREACH(pp, &gp->provider, provider) 786 g_orphan_provider(pp, ENXIO); 787 g_destroy_consumer(cp); 788 if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer)) 789 g_destroy_geom(gp); 790 else 791 gp->flags |= G_GEOM_WITHER; 792} 793 794/* 795 * Spoiling happens when a provider is opened for writing, but consumers 796 * which are configured by in-band data are attached (slicers for instance). 797 * Since the write might potentially change the in-band data, such consumers 798 * need to re-evaluate their existence after the writing session closes. 799 * We do this by (offering to) tear them down when the open for write happens 800 * in return for a re-taste when it closes again. 801 * Together with the fact that such consumers grab an 'e' bit whenever they 802 * are open, regardless of mode, this ends up DTRT. 803 */ 804 805static void 806g_spoil_event(void *arg, int flag) 807{ 808 struct g_provider *pp; 809 struct g_consumer *cp, *cp2; 810 811 g_topology_assert(); 812 if (flag == EV_CANCEL) 813 return; 814 pp = arg; 815 G_VALID_PROVIDER(pp); 816 for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) { 817 cp2 = LIST_NEXT(cp, consumers); 818 if (!cp->spoiled) 819 continue; 820 cp->spoiled = 0; 821 if (cp->geom->spoiled == NULL) 822 continue; 823 cp->geom->spoiled(cp); 824 g_topology_assert(); 825 } 826} 827 828void 829g_spoil(struct g_provider *pp, struct g_consumer *cp) 830{ 831 struct g_consumer *cp2; 832 833 g_topology_assert(); 834 G_VALID_PROVIDER(pp); 835 G_VALID_CONSUMER(cp); 836 837 LIST_FOREACH(cp2, &pp->consumers, consumers) { 838 if (cp2 == cp) 839 continue; 840/* 841 KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr)); 842 KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw)); 843*/ 844 KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace)); 845 cp2->spoiled++; 846 } 847 g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL); 848} 849 850int 851g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len) 852{ 853 int error, i; 854 855 i = len; 856 error = g_io_getattr(attr, cp, &i, var); 857 if (error) 858 return (error); 859 if (i != len) 860 return (EINVAL); 861 return (0); 862} 863 864#ifdef DIAGNOSTIC 865/* 866 * This function walks (topologically unsafely) the mesh and return a 867 * non-zero integer if it finds the argument pointer is an object. 868 * The return value indicates which type of object it is belived to be. 869 * If topology is not locked, this function is potentially dangerous, 870 * but since it is for debugging purposes and can be useful for instance 871 * from DDB, we do not assert topology lock is held. 872 */ 873int 874g_valid_obj(void const *ptr) 875{ 876 struct g_class *mp; 877 struct g_geom *gp; 878 struct g_consumer *cp; 879 struct g_provider *pp; 880 881 LIST_FOREACH(mp, &g_classes, class) { 882 if (ptr == mp) 883 return (1); 884 LIST_FOREACH(gp, &mp->geom, geom) { 885 if (ptr == gp) 886 return (2); 887 LIST_FOREACH(cp, &gp->consumer, consumer) 888 if (ptr == cp) 889 return (3); 890 LIST_FOREACH(pp, &gp->provider, provider) 891 if (ptr == pp) 892 return (4); 893 } 894 } 895 return(0); 896} 897#endif 898