Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_subr.c
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1 /*- 2 * Copyright (c) 2002 Poul-Henning Kamp 3 * Copyright (c) 2002 Networks Associates Technology, Inc. 4 * All rights reserved. 5 * 6 * This software was developed for the FreeBSD Project by Poul-Henning Kamp 7 * and NAI Labs, the Security Research Division of Network Associates, Inc. 8 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 9 * DARPA CHATS research program. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. The names of the authors may not be used to endorse or promote 20 * products derived from this software without specific prior written 21 * permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD: releng/5.3/sys/geom/geom_subr.c 136588 2004-10-16 08:43:07Z cvs2svn $"); 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/devicestat.h> 42 #include <sys/kernel.h> 43 #include <sys/malloc.h> 44 #include <sys/bio.h> 45 #include <sys/sysctl.h> 46 #include <sys/proc.h> 47 #include <sys/kthread.h> 48 #include <sys/lock.h> 49 #include <sys/mutex.h> 50 #include <sys/errno.h> 51 #include <sys/sbuf.h> 52 #include <geom/geom.h> 53 #include <geom/geom_int.h> 54 #include <machine/stdarg.h> 55 56 struct class_list_head g_classes = LIST_HEAD_INITIALIZER(g_classes); 57 static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms); 58 char *g_wait_event, *g_wait_up, *g_wait_down, *g_wait_sim; 59 60 struct g_hh00 { 61 struct g_class *mp; 62 int error; 63 }; 64 65 /* 66 * This event offers a new class a chance to taste all preexisting providers. 67 */ 68 static void 69 g_load_class(void *arg, int flag) 70 { 71 struct g_hh00 *hh; 72 struct g_class *mp2, *mp; 73 struct g_geom *gp; 74 struct g_provider *pp; 75 76 g_topology_assert(); 77 if (flag == EV_CANCEL) /* XXX: can't happen ? */ 78 return; 79 if (g_shutdown) 80 return; 81 82 hh = arg; 83 mp = hh->mp; 84 g_free(hh); 85 g_trace(G_T_TOPOLOGY, "g_load_class(%s)", mp->name); 86 KASSERT(mp->name != NULL && *mp->name != '\0', 87 ("GEOM class has no name")); 88 LIST_FOREACH(mp2, &g_classes, class) { 89 KASSERT(mp2 != mp, 90 ("The GEOM class %s already loaded", mp2->name)); 91 KASSERT(strcmp(mp2->name, mp->name) != 0, 92 ("A GEOM class named %s is already loaded", mp2->name)); 93 } 94 95 LIST_INIT(&mp->geom); 96 LIST_INSERT_HEAD(&g_classes, mp, class); 97 if (mp->init != NULL) 98 mp->init(mp); 99 if (mp->taste == NULL) 100 return; 101 LIST_FOREACH(mp2, &g_classes, class) { 102 if (mp == mp2) 103 continue; 104 LIST_FOREACH(gp, &mp2->geom, geom) { 105 LIST_FOREACH(pp, &gp->provider, provider) { 106 mp->taste(mp, pp, 0); 107 g_topology_assert(); 108 } 109 } 110 } 111 } 112 113 static void 114 g_unload_class(void *arg, int flag) 115 { 116 struct g_hh00 *hh; 117 struct g_class *mp; 118 struct g_geom *gp; 119 struct g_provider *pp; 120 struct g_consumer *cp; 121 int error; 122 123 g_topology_assert(); 124 hh = arg; 125 mp = hh->mp; 126 G_VALID_CLASS(mp); 127 g_trace(G_T_TOPOLOGY, "g_unload_class(%s)", mp->name); 128 129 /* 130 * We allow unloading if we have no geoms, or a class 131 * method we can use to get rid of them. 132 */ 133 if (!LIST_EMPTY(&mp->geom) && mp->destroy_geom == NULL) { 134 hh->error = EOPNOTSUPP; 135 return; 136 } 137 138 /* We refuse to unload if anything is open */ 139 LIST_FOREACH(gp, &mp->geom, geom) { 140 LIST_FOREACH(pp, &gp->provider, provider) 141 if (pp->acr || pp->acw || pp->ace) { 142 hh->error = EBUSY; 143 return; 144 } 145 LIST_FOREACH(cp, &gp->consumer, consumer) 146 if (cp->acr || cp->acw || cp->ace) { 147 hh->error = EBUSY; 148 return; 149 } 150 } 151 152 /* Bar new entries */ 153 mp->taste = NULL; 154 mp->config = NULL; 155 156 error = 0; 157 for (;;) { 158 gp = LIST_FIRST(&mp->geom); 159 if (gp == NULL) 160 break; 161 error = mp->destroy_geom(NULL, mp, gp); 162 if (error != 0) 163 break; 164 } 165 if (error == 0) { 166 if (mp->fini != NULL) 167 mp->fini(mp); 168 LIST_REMOVE(mp, class); 169 } 170 hh->error = error; 171 return; 172 } 173 174 int 175 g_modevent(module_t mod, int type, void *data) 176 { 177 struct g_hh00 *hh; 178 int error; 179 static int g_ignition; 180 struct g_class *mp; 181 182 mp = data; 183 if (mp->version != G_VERSION) { 184 printf("GEOM class %s has Wrong version %x\n", 185 mp->name, mp->version); 186 return (EINVAL); 187 } 188 if (!g_ignition) { 189 g_ignition++; 190 g_init(); 191 } 192 hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO); 193 hh->mp = data; 194 error = EOPNOTSUPP; 195 switch (type) { 196 case MOD_LOAD: 197 g_trace(G_T_TOPOLOGY, "g_modevent(%s, LOAD)", hh->mp->name); 198 g_post_event(g_load_class, hh, M_WAITOK, NULL); 199 error = 0; 200 break; 201 case MOD_UNLOAD: 202 g_trace(G_T_TOPOLOGY, "g_modevent(%s, UNLOAD)", hh->mp->name); 203 error = g_waitfor_event(g_unload_class, hh, M_WAITOK, NULL); 204 if (error == 0) 205 error = hh->error; 206 if (error == 0) { 207 g_waitidle(); 208 KASSERT(LIST_EMPTY(&hh->mp->geom), 209 ("Unloaded class (%s) still has geom", hh->mp->name)); 210 } 211 g_free(hh); 212 break; 213 default: 214 g_free(hh); 215 break; 216 } 217 return (error); 218 } 219 220 struct g_geom * 221 g_new_geomf(struct g_class *mp, const char *fmt, ...) 222 { 223 struct g_geom *gp; 224 va_list ap; 225 struct sbuf *sb; 226 227 g_topology_assert(); 228 G_VALID_CLASS(mp); 229 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 230 va_start(ap, fmt); 231 sbuf_vprintf(sb, fmt, ap); 232 va_end(ap); 233 sbuf_finish(sb); 234 gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO); 235 gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO); 236 gp->class = mp; 237 gp->rank = 1; 238 LIST_INIT(&gp->consumer); 239 LIST_INIT(&gp->provider); 240 LIST_INSERT_HEAD(&mp->geom, gp, geom); 241 TAILQ_INSERT_HEAD(&geoms, gp, geoms); 242 strcpy(gp->name, sbuf_data(sb)); 243 sbuf_delete(sb); 244 /* Fill in defaults from class */ 245 gp->start = mp->start; 246 gp->spoiled = mp->spoiled; 247 gp->dumpconf = mp->dumpconf; 248 gp->access = mp->access; 249 gp->orphan = mp->orphan; 250 gp->ioctl = mp->ioctl; 251 return (gp); 252 } 253 254 void 255 g_destroy_geom(struct g_geom *gp) 256 { 257 258 g_topology_assert(); 259 G_VALID_GEOM(gp); 260 g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name); 261 KASSERT(LIST_EMPTY(&gp->consumer), 262 ("g_destroy_geom(%s) with consumer(s) [%p]", 263 gp->name, LIST_FIRST(&gp->consumer))); 264 KASSERT(LIST_EMPTY(&gp->provider), 265 ("g_destroy_geom(%s) with provider(s) [%p]", 266 gp->name, LIST_FIRST(&gp->provider))); 267 g_cancel_event(gp); 268 LIST_REMOVE(gp, geom); 269 TAILQ_REMOVE(&geoms, gp, geoms); 270 g_free(gp->name); 271 g_free(gp); 272 } 273 274 /* 275 * This function is called (repeatedly) until the has withered away. 276 */ 277 void 278 g_wither_geom(struct g_geom *gp, int error) 279 { 280 struct g_provider *pp; 281 282 g_topology_assert(); 283 G_VALID_GEOM(gp); 284 g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name); 285 if (!(gp->flags & G_GEOM_WITHER)) { 286 gp->flags |= G_GEOM_WITHER; 287 LIST_FOREACH(pp, &gp->provider, provider) 288 if (!(pp->flags & G_PF_ORPHAN)) 289 g_orphan_provider(pp, error); 290 } 291 g_do_wither(); 292 } 293 294 /* 295 * This function is called (repeatedly) until we cant wash away more 296 * withered bits at present. Return value contains two bits. Bit 0 297 * set means "withering stuff we can't wash now", bit 1 means "call 298 * me again, there may be stuff I didn't get the first time around. 299 */ 300 int 301 g_wither_washer() 302 { 303 struct g_class *mp; 304 struct g_geom *gp, *gp2; 305 struct g_provider *pp, *pp2; 306 struct g_consumer *cp, *cp2; 307 int result; 308 309 result = 0; 310 g_topology_assert(); 311 LIST_FOREACH(mp, &g_classes, class) { 312 LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) { 313 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) { 314 if (!(pp->flags & G_PF_WITHER)) 315 continue; 316 if (LIST_EMPTY(&pp->consumers)) 317 g_destroy_provider(pp); 318 else 319 result |= 1; 320 } 321 if (!(gp->flags & G_GEOM_WITHER)) 322 continue; 323 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) { 324 if (LIST_EMPTY(&pp->consumers)) 325 g_destroy_provider(pp); 326 else 327 result |= 1; 328 } 329 LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp2) { 330 if (cp->acr || cp->acw || cp->ace) { 331 result |= 1; 332 continue; 333 } 334 if (cp->provider != NULL) 335 g_detach(cp); 336 g_destroy_consumer(cp); 337 result |= 2; 338 } 339 if (LIST_EMPTY(&gp->provider) && 340 LIST_EMPTY(&gp->consumer)) 341 g_destroy_geom(gp); 342 else 343 result |= 1; 344 } 345 } 346 return (result); 347 } 348 349 struct g_consumer * 350 g_new_consumer(struct g_geom *gp) 351 { 352 struct g_consumer *cp; 353 354 g_topology_assert(); 355 G_VALID_GEOM(gp); 356 KASSERT(!(gp->flags & G_GEOM_WITHER), 357 ("g_new_consumer on WITHERing geom(%s) (class %s)", 358 gp->name, gp->class->name)); 359 KASSERT(gp->orphan != NULL, 360 ("g_new_consumer on geom(%s) (class %s) without orphan", 361 gp->name, gp->class->name)); 362 363 cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO); 364 cp->geom = gp; 365 cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED, 366 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX); 367 LIST_INSERT_HEAD(&gp->consumer, cp, consumer); 368 return(cp); 369 } 370 371 void 372 g_destroy_consumer(struct g_consumer *cp) 373 { 374 struct g_geom *gp; 375 376 g_topology_assert(); 377 G_VALID_CONSUMER(cp); 378 g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp); 379 KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached")); 380 KASSERT (cp->acr == 0, ("g_destroy_consumer with acr")); 381 KASSERT (cp->acw == 0, ("g_destroy_consumer with acw")); 382 KASSERT (cp->ace == 0, ("g_destroy_consumer with ace")); 383 g_cancel_event(cp); 384 gp = cp->geom; 385 LIST_REMOVE(cp, consumer); 386 devstat_remove_entry(cp->stat); 387 g_free(cp); 388 if (gp->flags & G_GEOM_WITHER) 389 g_do_wither(); 390 } 391 392 static void 393 g_new_provider_event(void *arg, int flag) 394 { 395 struct g_class *mp; 396 struct g_provider *pp; 397 struct g_consumer *cp; 398 int i; 399 400 g_topology_assert(); 401 if (flag == EV_CANCEL) 402 return; 403 if (g_shutdown) 404 return; 405 pp = arg; 406 G_VALID_PROVIDER(pp); 407 LIST_FOREACH(mp, &g_classes, class) { 408 if (mp->taste == NULL) 409 continue; 410 i = 1; 411 LIST_FOREACH(cp, &pp->consumers, consumers) 412 if (cp->geom->class == mp) 413 i = 0; 414 if (!i) 415 continue; 416 mp->taste(mp, pp, 0); 417 g_topology_assert(); 418 } 419 } 420 421 422 struct g_provider * 423 g_new_providerf(struct g_geom *gp, const char *fmt, ...) 424 { 425 struct g_provider *pp; 426 struct sbuf *sb; 427 va_list ap; 428 429 g_topology_assert(); 430 G_VALID_GEOM(gp); 431 KASSERT(gp->access != NULL, 432 ("new provider on geom(%s) without ->access (class %s)", 433 gp->name, gp->class->name)); 434 KASSERT(gp->start != NULL, 435 ("new provider on geom(%s) without ->start (class %s)", 436 gp->name, gp->class->name)); 437 KASSERT(!(gp->flags & G_GEOM_WITHER), 438 ("new provider on WITHERing geom(%s) (class %s)", 439 gp->name, gp->class->name)); 440 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 441 va_start(ap, fmt); 442 sbuf_vprintf(sb, fmt, ap); 443 va_end(ap); 444 sbuf_finish(sb); 445 pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO); 446 pp->name = (char *)(pp + 1); 447 strcpy(pp->name, sbuf_data(sb)); 448 sbuf_delete(sb); 449 LIST_INIT(&pp->consumers); 450 pp->error = ENXIO; 451 pp->geom = gp; 452 pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED, 453 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX); 454 LIST_INSERT_HEAD(&gp->provider, pp, provider); 455 g_post_event(g_new_provider_event, pp, M_WAITOK, pp, gp, NULL); 456 return (pp); 457 } 458 459 void 460 g_error_provider(struct g_provider *pp, int error) 461 { 462 463 /* G_VALID_PROVIDER(pp); We may not have g_topology */ 464 pp->error = error; 465 } 466 467 struct g_provider * 468 g_provider_by_name(char const *arg) 469 { 470 struct g_class *cp; 471 struct g_geom *gp; 472 struct g_provider *pp; 473 474 LIST_FOREACH(cp, &g_classes, class) { 475 LIST_FOREACH(gp, &cp->geom, geom) { 476 LIST_FOREACH(pp, &gp->provider, provider) { 477 if (!strcmp(arg, pp->name)) 478 return (pp); 479 } 480 } 481 } 482 return (NULL); 483 } 484 485 void 486 g_destroy_provider(struct g_provider *pp) 487 { 488 struct g_geom *gp; 489 490 g_topology_assert(); 491 G_VALID_PROVIDER(pp); 492 KASSERT(LIST_EMPTY(&pp->consumers), 493 ("g_destroy_provider but attached")); 494 KASSERT (pp->acr == 0, ("g_destroy_provider with acr")); 495 KASSERT (pp->acw == 0, ("g_destroy_provider with acw")); 496 KASSERT (pp->acw == 0, ("g_destroy_provider with ace")); 497 g_cancel_event(pp); 498 LIST_REMOVE(pp, provider); 499 gp = pp->geom; 500 devstat_remove_entry(pp->stat); 501 g_free(pp); 502 if ((gp->flags & G_GEOM_WITHER)) 503 g_do_wither(); 504 } 505 506 /* 507 * We keep the "geoms" list sorted by topological order (== increasing 508 * numerical rank) at all times. 509 * When an attach is done, the attaching geoms rank is invalidated 510 * and it is moved to the tail of the list. 511 * All geoms later in the sequence has their ranks reevaluated in 512 * sequence. If we cannot assign rank to a geom because it's 513 * prerequisites do not have rank, we move that element to the tail 514 * of the sequence with invalid rank as well. 515 * At some point we encounter our original geom and if we stil fail 516 * to assign it a rank, there must be a loop and we fail back to 517 * g_attach() which detach again and calls redo_rank again 518 * to fix up the damage. 519 * It would be much simpler code wise to do it recursively, but we 520 * can't risk that on the kernel stack. 521 */ 522 523 static int 524 redo_rank(struct g_geom *gp) 525 { 526 struct g_consumer *cp; 527 struct g_geom *gp1, *gp2; 528 int n, m; 529 530 g_topology_assert(); 531 G_VALID_GEOM(gp); 532 533 /* Invalidate this geoms rank and move it to the tail */ 534 gp1 = TAILQ_NEXT(gp, geoms); 535 if (gp1 != NULL) { 536 gp->rank = 0; 537 TAILQ_REMOVE(&geoms, gp, geoms); 538 TAILQ_INSERT_TAIL(&geoms, gp, geoms); 539 } else { 540 gp1 = gp; 541 } 542 543 /* re-rank the rest of the sequence */ 544 for (; gp1 != NULL; gp1 = gp2) { 545 gp1->rank = 0; 546 m = 1; 547 LIST_FOREACH(cp, &gp1->consumer, consumer) { 548 if (cp->provider == NULL) 549 continue; 550 n = cp->provider->geom->rank; 551 if (n == 0) { 552 m = 0; 553 break; 554 } else if (n >= m) 555 m = n + 1; 556 } 557 gp1->rank = m; 558 gp2 = TAILQ_NEXT(gp1, geoms); 559 560 /* got a rank, moving on */ 561 if (m != 0) 562 continue; 563 564 /* no rank to original geom means loop */ 565 if (gp == gp1) 566 return (ELOOP); 567 568 /* no rank, put it at the end move on */ 569 TAILQ_REMOVE(&geoms, gp1, geoms); 570 TAILQ_INSERT_TAIL(&geoms, gp1, geoms); 571 } 572 return (0); 573 } 574 575 int 576 g_attach(struct g_consumer *cp, struct g_provider *pp) 577 { 578 int error; 579 580 g_topology_assert(); 581 G_VALID_CONSUMER(cp); 582 G_VALID_PROVIDER(pp); 583 KASSERT(cp->provider == NULL, ("attach but attached")); 584 cp->provider = pp; 585 LIST_INSERT_HEAD(&pp->consumers, cp, consumers); 586 error = redo_rank(cp->geom); 587 if (error) { 588 LIST_REMOVE(cp, consumers); 589 cp->provider = NULL; 590 redo_rank(cp->geom); 591 } 592 return (error); 593 } 594 595 void 596 g_detach(struct g_consumer *cp) 597 { 598 struct g_provider *pp; 599 600 g_topology_assert(); 601 G_VALID_CONSUMER(cp); 602 g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp); 603 KASSERT(cp->provider != NULL, ("detach but not attached")); 604 KASSERT(cp->acr == 0, ("detach but nonzero acr")); 605 KASSERT(cp->acw == 0, ("detach but nonzero acw")); 606 KASSERT(cp->ace == 0, ("detach but nonzero ace")); 607 KASSERT(cp->nstart == cp->nend, 608 ("detach with active requests")); 609 pp = cp->provider; 610 LIST_REMOVE(cp, consumers); 611 cp->provider = NULL; 612 if (pp->geom->flags & G_GEOM_WITHER) 613 g_do_wither(); 614 else if (pp->flags & G_PF_WITHER) 615 g_do_wither(); 616 redo_rank(cp->geom); 617 } 618 619 /* 620 * g_access() 621 * 622 * Access-check with delta values. The question asked is "can provider 623 * "cp" change the access counters by the relative amounts dc[rwe] ?" 624 */ 625 626 int 627 g_access(struct g_consumer *cp, int dcr, int dcw, int dce) 628 { 629 struct g_provider *pp; 630 int pr,pw,pe; 631 int error; 632 633 g_topology_assert(); 634 G_VALID_CONSUMER(cp); 635 pp = cp->provider; 636 KASSERT(pp != NULL, ("access but not attached")); 637 G_VALID_PROVIDER(pp); 638 639 g_trace(G_T_ACCESS, "g_access(%p(%s), %d, %d, %d)", 640 cp, pp->name, dcr, dcw, dce); 641 642 KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr")); 643 KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw")); 644 KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace")); 645 KASSERT(dcr != 0 || dcw != 0 || dce != 0, ("NOP access request")); 646 KASSERT(pp->geom->access != NULL, ("NULL geom->access")); 647 648 /* 649 * If our class cares about being spoiled, and we have been, we 650 * are probably just ahead of the event telling us that. Fail 651 * now rather than having to unravel this later. 652 */ 653 if (cp->geom->spoiled != NULL && cp->spoiled && 654 (dcr > 0 || dcw > 0 || dce > 0)) 655 return (ENXIO); 656 657 /* 658 * Figure out what counts the provider would have had, if this 659 * consumer had (r0w0e0) at this time. 660 */ 661 pr = pp->acr - cp->acr; 662 pw = pp->acw - cp->acw; 663 pe = pp->ace - cp->ace; 664 665 g_trace(G_T_ACCESS, 666 "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)", 667 dcr, dcw, dce, 668 cp->acr, cp->acw, cp->ace, 669 pp->acr, pp->acw, pp->ace, 670 pp, pp->name); 671 672 /* If foot-shooting is enabled, any open on rank#1 is OK */ 673 if ((g_debugflags & 16) && pp->geom->rank == 1) 674 ; 675 /* If we try exclusive but already write: fail */ 676 else if (dce > 0 && pw > 0) 677 return (EPERM); 678 /* If we try write but already exclusive: fail */ 679 else if (dcw > 0 && pe > 0) 680 return (EPERM); 681 /* If we try to open more but provider is error'ed: fail */ 682 else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0) 683 return (pp->error); 684 685 /* Ok then... */ 686 687 error = pp->geom->access(pp, dcr, dcw, dce); 688 KASSERT(dcr > 0 || dcw > 0 || dce > 0 || error == 0, 689 ("Geom provider %s::%s failed closing ->access()", 690 pp->geom->class->name, pp->name)); 691 if (!error) { 692 /* 693 * If we open first write, spoil any partner consumers. 694 * If we close last write, trigger re-taste. 695 */ 696 if (pp->acw == 0 && dcw != 0) 697 g_spoil(pp, cp); 698 else if (pp->acw != 0 && pp->acw == -dcw && 699 !(pp->geom->flags & G_GEOM_WITHER)) 700 g_post_event(g_new_provider_event, pp, M_WAITOK, 701 pp, NULL); 702 703 pp->acr += dcr; 704 pp->acw += dcw; 705 pp->ace += dce; 706 cp->acr += dcr; 707 cp->acw += dcw; 708 cp->ace += dce; 709 if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0) 710 KASSERT(pp->sectorsize > 0, 711 ("Provider %s lacks sectorsize", pp->name)); 712 } 713 return (error); 714 } 715 716 int 717 g_handleattr_int(struct bio *bp, const char *attribute, int val) 718 { 719 720 return (g_handleattr(bp, attribute, &val, sizeof val)); 721 } 722 723 int 724 g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val) 725 { 726 727 return (g_handleattr(bp, attribute, &val, sizeof val)); 728 } 729 730 int 731 g_handleattr(struct bio *bp, const char *attribute, void *val, int len) 732 { 733 int error; 734 735 if (strcmp(bp->bio_attribute, attribute)) 736 return (0); 737 if (bp->bio_length != len) { 738 printf("bio_length %jd len %d -> EFAULT\n", 739 (intmax_t)bp->bio_length, len); 740 error = EFAULT; 741 } else { 742 error = 0; 743 bcopy(val, bp->bio_data, len); 744 bp->bio_completed = len; 745 } 746 g_io_deliver(bp, error); 747 return (1); 748 } 749 750 int 751 g_std_access(struct g_provider *pp, 752 int dr __unused, int dw __unused, int de __unused) 753 { 754 755 g_topology_assert(); 756 G_VALID_PROVIDER(pp); 757 return (0); 758 } 759 760 void 761 g_std_done(struct bio *bp) 762 { 763 struct bio *bp2; 764 765 bp2 = bp->bio_parent; 766 if (bp2->bio_error == 0) 767 bp2->bio_error = bp->bio_error; 768 bp2->bio_completed += bp->bio_completed; 769 g_destroy_bio(bp); 770 bp2->bio_inbed++; 771 if (bp2->bio_children == bp2->bio_inbed) 772 g_io_deliver(bp2, bp2->bio_error); 773 } 774 775 /* XXX: maybe this is only g_slice_spoiled */ 776 777 void 778 g_std_spoiled(struct g_consumer *cp) 779 { 780 struct g_geom *gp; 781 struct g_provider *pp; 782 783 g_topology_assert(); 784 G_VALID_CONSUMER(cp); 785 g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp); 786 g_detach(cp); 787 gp = cp->geom; 788 LIST_FOREACH(pp, &gp->provider, provider) 789 g_orphan_provider(pp, ENXIO); 790 g_destroy_consumer(cp); 791 if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer)) 792 g_destroy_geom(gp); 793 else 794 gp->flags |= G_GEOM_WITHER; 795 } 796 797 /* 798 * Spoiling happens when a provider is opened for writing, but consumers 799 * which are configured by in-band data are attached (slicers for instance). 800 * Since the write might potentially change the in-band data, such consumers 801 * need to re-evaluate their existence after the writing session closes. 802 * We do this by (offering to) tear them down when the open for write happens 803 * in return for a re-taste when it closes again. 804 * Together with the fact that such consumers grab an 'e' bit whenever they 805 * are open, regardless of mode, this ends up DTRT. 806 */ 807 808 static void 809 g_spoil_event(void *arg, int flag) 810 { 811 struct g_provider *pp; 812 struct g_consumer *cp, *cp2; 813 814 g_topology_assert(); 815 if (flag == EV_CANCEL) 816 return; 817 pp = arg; 818 G_VALID_PROVIDER(pp); 819 for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) { 820 cp2 = LIST_NEXT(cp, consumers); 821 if (!cp->spoiled) 822 continue; 823 cp->spoiled = 0; 824 if (cp->geom->spoiled == NULL) 825 continue; 826 cp->geom->spoiled(cp); 827 g_topology_assert(); 828 } 829 } 830 831 void 832 g_spoil(struct g_provider *pp, struct g_consumer *cp) 833 { 834 struct g_consumer *cp2; 835 836 g_topology_assert(); 837 G_VALID_PROVIDER(pp); 838 G_VALID_CONSUMER(cp); 839 840 LIST_FOREACH(cp2, &pp->consumers, consumers) { 841 if (cp2 == cp) 842 continue; 843 /* 844 KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr)); 845 KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw)); 846 */ 847 KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace)); 848 cp2->spoiled++; 849 } 850 g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL); 851 } 852 853 int 854 g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len) 855 { 856 int error, i; 857 858 i = len; 859 error = g_io_getattr(attr, cp, &i, var); 860 if (error) 861 return (error); 862 if (i != len) 863 return (EINVAL); 864 return (0); 865 } 866 867 #ifdef DIAGNOSTIC 868 /* 869 * This function walks (topologically unsafely) the mesh and return a 870 * non-zero integer if it finds the argument pointer is an object. 871 * The return value indicates which type of object it is belived to be. 872 * If topology is not locked, this function is potentially dangerous, 873 * but since it is for debugging purposes and can be useful for instance 874 * from DDB, we do not assert topology lock is held. 875 */ 876 int 877 g_valid_obj(void const *ptr) 878 { 879 struct g_class *mp; 880 struct g_geom *gp; 881 struct g_consumer *cp; 882 struct g_provider *pp; 883 884 LIST_FOREACH(mp, &g_classes, class) { 885 if (ptr == mp) 886 return (1); 887 LIST_FOREACH(gp, &mp->geom, geom) { 888 if (ptr == gp) 889 return (2); 890 LIST_FOREACH(cp, &gp->consumer, consumer) 891 if (ptr == cp) 892 return (3); 893 LIST_FOREACH(pp, &gp->provider, provider) 894 if (ptr == pp) 895 return (4); 896 } 897 } 898 return(0); 899 } 900 #endif
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