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/5.4/sys/geom/geom_subr.c 145335 2005-04-20 19:11:07Z 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 KASSERT(LIST_EMPTY(&hh->mp->geom), 208 ("Unloaded class (%s) still has geom", hh->mp->name)); 209 } 210 g_free(hh); 211 break; 212 default: 213 g_free(hh); 214 break; 215 } 216 return (error); 217 } 218 219 struct g_geom * 220 g_new_geomf(struct g_class *mp, const char *fmt, ...) 221 { 222 struct g_geom *gp; 223 va_list ap; 224 struct sbuf *sb; 225 226 g_topology_assert(); 227 G_VALID_CLASS(mp); 228 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 229 va_start(ap, fmt); 230 sbuf_vprintf(sb, fmt, ap); 231 va_end(ap); 232 sbuf_finish(sb); 233 gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO); 234 gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO); 235 gp->class = mp; 236 gp->rank = 1; 237 LIST_INIT(&gp->consumer); 238 LIST_INIT(&gp->provider); 239 LIST_INSERT_HEAD(&mp->geom, gp, geom); 240 TAILQ_INSERT_HEAD(&geoms, gp, geoms); 241 strcpy(gp->name, sbuf_data(sb)); 242 sbuf_delete(sb); 243 /* Fill in defaults from class */ 244 gp->start = mp->start; 245 gp->spoiled = mp->spoiled; 246 gp->dumpconf = mp->dumpconf; 247 gp->access = mp->access; 248 gp->orphan = mp->orphan; 249 gp->ioctl = mp->ioctl; 250 return (gp); 251 } 252 253 void 254 g_destroy_geom(struct g_geom *gp) 255 { 256 257 g_topology_assert(); 258 G_VALID_GEOM(gp); 259 g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name); 260 KASSERT(LIST_EMPTY(&gp->consumer), 261 ("g_destroy_geom(%s) with consumer(s) [%p]", 262 gp->name, LIST_FIRST(&gp->consumer))); 263 KASSERT(LIST_EMPTY(&gp->provider), 264 ("g_destroy_geom(%s) with provider(s) [%p]", 265 gp->name, LIST_FIRST(&gp->provider))); 266 g_cancel_event(gp); 267 LIST_REMOVE(gp, geom); 268 TAILQ_REMOVE(&geoms, gp, geoms); 269 g_free(gp->name); 270 g_free(gp); 271 } 272 273 /* 274 * This function is called (repeatedly) until the has withered away. 275 */ 276 void 277 g_wither_geom(struct g_geom *gp, int error) 278 { 279 struct g_provider *pp; 280 281 g_topology_assert(); 282 G_VALID_GEOM(gp); 283 g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name); 284 if (!(gp->flags & G_GEOM_WITHER)) { 285 gp->flags |= G_GEOM_WITHER; 286 LIST_FOREACH(pp, &gp->provider, provider) 287 if (!(pp->flags & G_PF_ORPHAN)) 288 g_orphan_provider(pp, error); 289 } 290 g_do_wither(); 291 } 292 293 /* 294 * This function is called (repeatedly) until we cant wash away more 295 * withered bits at present. Return value contains two bits. Bit 0 296 * set means "withering stuff we can't wash now", bit 1 means "call 297 * me again, there may be stuff I didn't get the first time around. 298 */ 299 int 300 g_wither_washer() 301 { 302 struct g_class *mp; 303 struct g_geom *gp, *gp2; 304 struct g_provider *pp, *pp2; 305 struct g_consumer *cp, *cp2; 306 int result; 307 308 result = 0; 309 g_topology_assert(); 310 LIST_FOREACH(mp, &g_classes, class) { 311 LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) { 312 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) { 313 if (!(pp->flags & G_PF_WITHER)) 314 continue; 315 if (LIST_EMPTY(&pp->consumers)) 316 g_destroy_provider(pp); 317 else 318 result |= 1; 319 } 320 if (!(gp->flags & G_GEOM_WITHER)) 321 continue; 322 LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) { 323 if (LIST_EMPTY(&pp->consumers)) 324 g_destroy_provider(pp); 325 else 326 result |= 1; 327 } 328 LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp2) { 329 if (cp->acr || cp->acw || cp->ace) { 330 result |= 1; 331 continue; 332 } 333 if (cp->provider != NULL) 334 g_detach(cp); 335 g_destroy_consumer(cp); 336 result |= 2; 337 } 338 if (LIST_EMPTY(&gp->provider) && 339 LIST_EMPTY(&gp->consumer)) 340 g_destroy_geom(gp); 341 else 342 result |= 1; 343 } 344 } 345 return (result); 346 } 347 348 struct g_consumer * 349 g_new_consumer(struct g_geom *gp) 350 { 351 struct g_consumer *cp; 352 353 g_topology_assert(); 354 G_VALID_GEOM(gp); 355 KASSERT(!(gp->flags & G_GEOM_WITHER), 356 ("g_new_consumer on WITHERing geom(%s) (class %s)", 357 gp->name, gp->class->name)); 358 KASSERT(gp->orphan != NULL, 359 ("g_new_consumer on geom(%s) (class %s) without orphan", 360 gp->name, gp->class->name)); 361 362 cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO); 363 cp->geom = gp; 364 cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED, 365 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX); 366 LIST_INSERT_HEAD(&gp->consumer, cp, consumer); 367 return(cp); 368 } 369 370 void 371 g_destroy_consumer(struct g_consumer *cp) 372 { 373 struct g_geom *gp; 374 375 g_topology_assert(); 376 G_VALID_CONSUMER(cp); 377 g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp); 378 KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached")); 379 KASSERT (cp->acr == 0, ("g_destroy_consumer with acr")); 380 KASSERT (cp->acw == 0, ("g_destroy_consumer with acw")); 381 KASSERT (cp->ace == 0, ("g_destroy_consumer with ace")); 382 g_cancel_event(cp); 383 gp = cp->geom; 384 LIST_REMOVE(cp, consumer); 385 devstat_remove_entry(cp->stat); 386 g_free(cp); 387 if (gp->flags & G_GEOM_WITHER) 388 g_do_wither(); 389 } 390 391 static void 392 g_new_provider_event(void *arg, int flag) 393 { 394 struct g_class *mp; 395 struct g_provider *pp; 396 struct g_consumer *cp; 397 int i; 398 399 g_topology_assert(); 400 if (flag == EV_CANCEL) 401 return; 402 if (g_shutdown) 403 return; 404 pp = arg; 405 G_VALID_PROVIDER(pp); 406 LIST_FOREACH(mp, &g_classes, class) { 407 if (mp->taste == NULL) 408 continue; 409 i = 1; 410 LIST_FOREACH(cp, &pp->consumers, consumers) 411 if (cp->geom->class == mp) 412 i = 0; 413 if (!i) 414 continue; 415 mp->taste(mp, pp, 0); 416 g_topology_assert(); 417 } 418 } 419 420 421 struct g_provider * 422 g_new_providerf(struct g_geom *gp, const char *fmt, ...) 423 { 424 struct g_provider *pp; 425 struct sbuf *sb; 426 va_list ap; 427 428 g_topology_assert(); 429 G_VALID_GEOM(gp); 430 KASSERT(gp->access != NULL, 431 ("new provider on geom(%s) without ->access (class %s)", 432 gp->name, gp->class->name)); 433 KASSERT(gp->start != NULL, 434 ("new provider on geom(%s) without ->start (class %s)", 435 gp->name, gp->class->name)); 436 KASSERT(!(gp->flags & G_GEOM_WITHER), 437 ("new provider on WITHERing geom(%s) (class %s)", 438 gp->name, gp->class->name)); 439 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 440 va_start(ap, fmt); 441 sbuf_vprintf(sb, fmt, ap); 442 va_end(ap); 443 sbuf_finish(sb); 444 pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO); 445 pp->name = (char *)(pp + 1); 446 strcpy(pp->name, sbuf_data(sb)); 447 sbuf_delete(sb); 448 LIST_INIT(&pp->consumers); 449 pp->error = ENXIO; 450 pp->geom = gp; 451 pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED, 452 DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX); 453 LIST_INSERT_HEAD(&gp->provider, pp, provider); 454 g_post_event(g_new_provider_event, pp, M_WAITOK, pp, gp, NULL); 455 return (pp); 456 } 457 458 void 459 g_error_provider(struct g_provider *pp, int error) 460 { 461 462 /* G_VALID_PROVIDER(pp); We may not have g_topology */ 463 pp->error = error; 464 } 465 466 struct g_provider * 467 g_provider_by_name(char const *arg) 468 { 469 struct g_class *cp; 470 struct g_geom *gp; 471 struct g_provider *pp; 472 473 LIST_FOREACH(cp, &g_classes, class) { 474 LIST_FOREACH(gp, &cp->geom, geom) { 475 LIST_FOREACH(pp, &gp->provider, provider) { 476 if (!strcmp(arg, pp->name)) 477 return (pp); 478 } 479 } 480 } 481 return (NULL); 482 } 483 484 void 485 g_destroy_provider(struct g_provider *pp) 486 { 487 struct g_geom *gp; 488 489 g_topology_assert(); 490 G_VALID_PROVIDER(pp); 491 KASSERT(LIST_EMPTY(&pp->consumers), 492 ("g_destroy_provider but attached")); 493 KASSERT (pp->acr == 0, ("g_destroy_provider with acr")); 494 KASSERT (pp->acw == 0, ("g_destroy_provider with acw")); 495 KASSERT (pp->acw == 0, ("g_destroy_provider with ace")); 496 g_cancel_event(pp); 497 LIST_REMOVE(pp, provider); 498 gp = pp->geom; 499 devstat_remove_entry(pp->stat); 500 g_free(pp); 501 if ((gp->flags & G_GEOM_WITHER)) 502 g_do_wither(); 503 } 504 505 /* 506 * We keep the "geoms" list sorted by topological order (== increasing 507 * numerical rank) at all times. 508 * When an attach is done, the attaching geoms rank is invalidated 509 * and it is moved to the tail of the list. 510 * All geoms later in the sequence has their ranks reevaluated in 511 * sequence. If we cannot assign rank to a geom because it's 512 * prerequisites do not have rank, we move that element to the tail 513 * of the sequence with invalid rank as well. 514 * At some point we encounter our original geom and if we stil fail 515 * to assign it a rank, there must be a loop and we fail back to 516 * g_attach() which detach again and calls redo_rank again 517 * to fix up the damage. 518 * It would be much simpler code wise to do it recursively, but we 519 * can't risk that on the kernel stack. 520 */ 521 522 static int 523 redo_rank(struct g_geom *gp) 524 { 525 struct g_consumer *cp; 526 struct g_geom *gp1, *gp2; 527 int n, m; 528 529 g_topology_assert(); 530 G_VALID_GEOM(gp); 531 532 /* Invalidate this geoms rank and move it to the tail */ 533 gp1 = TAILQ_NEXT(gp, geoms); 534 if (gp1 != NULL) { 535 gp->rank = 0; 536 TAILQ_REMOVE(&geoms, gp, geoms); 537 TAILQ_INSERT_TAIL(&geoms, gp, geoms); 538 } else { 539 gp1 = gp; 540 } 541 542 /* re-rank the rest of the sequence */ 543 for (; gp1 != NULL; gp1 = gp2) { 544 gp1->rank = 0; 545 m = 1; 546 LIST_FOREACH(cp, &gp1->consumer, consumer) { 547 if (cp->provider == NULL) 548 continue; 549 n = cp->provider->geom->rank; 550 if (n == 0) { 551 m = 0; 552 break; 553 } else if (n >= m) 554 m = n + 1; 555 } 556 gp1->rank = m; 557 gp2 = TAILQ_NEXT(gp1, geoms); 558 559 /* got a rank, moving on */ 560 if (m != 0) 561 continue; 562 563 /* no rank to original geom means loop */ 564 if (gp == gp1) 565 return (ELOOP); 566 567 /* no rank, put it at the end move on */ 568 TAILQ_REMOVE(&geoms, gp1, geoms); 569 TAILQ_INSERT_TAIL(&geoms, gp1, geoms); 570 } 571 return (0); 572 } 573 574 int 575 g_attach(struct g_consumer *cp, struct g_provider *pp) 576 { 577 int error; 578 579 g_topology_assert(); 580 G_VALID_CONSUMER(cp); 581 G_VALID_PROVIDER(pp); 582 KASSERT(cp->provider == NULL, ("attach but attached")); 583 cp->provider = pp; 584 LIST_INSERT_HEAD(&pp->consumers, cp, consumers); 585 error = redo_rank(cp->geom); 586 if (error) { 587 LIST_REMOVE(cp, consumers); 588 cp->provider = NULL; 589 redo_rank(cp->geom); 590 } 591 return (error); 592 } 593 594 void 595 g_detach(struct g_consumer *cp) 596 { 597 struct g_provider *pp; 598 599 g_topology_assert(); 600 G_VALID_CONSUMER(cp); 601 g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp); 602 KASSERT(cp->provider != NULL, ("detach but not attached")); 603 KASSERT(cp->acr == 0, ("detach but nonzero acr")); 604 KASSERT(cp->acw == 0, ("detach but nonzero acw")); 605 KASSERT(cp->ace == 0, ("detach but nonzero ace")); 606 KASSERT(cp->nstart == cp->nend, 607 ("detach with active requests")); 608 pp = cp->provider; 609 LIST_REMOVE(cp, consumers); 610 cp->provider = NULL; 611 if (pp->geom->flags & G_GEOM_WITHER) 612 g_do_wither(); 613 else if (pp->flags & G_PF_WITHER) 614 g_do_wither(); 615 redo_rank(cp->geom); 616 } 617 618 /* 619 * g_access() 620 * 621 * Access-check with delta values. The question asked is "can provider 622 * "cp" change the access counters by the relative amounts dc[rwe] ?" 623 */ 624 625 int 626 g_access(struct g_consumer *cp, int dcr, int dcw, int dce) 627 { 628 struct g_provider *pp; 629 int pr,pw,pe; 630 int error; 631 632 g_topology_assert(); 633 G_VALID_CONSUMER(cp); 634 pp = cp->provider; 635 KASSERT(pp != NULL, ("access but not attached")); 636 G_VALID_PROVIDER(pp); 637 638 g_trace(G_T_ACCESS, "g_access(%p(%s), %d, %d, %d)", 639 cp, pp->name, dcr, dcw, dce); 640 641 KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr")); 642 KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw")); 643 KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace")); 644 KASSERT(dcr != 0 || dcw != 0 || dce != 0, ("NOP access request")); 645 KASSERT(pp->geom->access != NULL, ("NULL geom->access")); 646 647 /* 648 * If our class cares about being spoiled, and we have been, we 649 * are probably just ahead of the event telling us that. Fail 650 * now rather than having to unravel this later. 651 */ 652 if (cp->geom->spoiled != NULL && cp->spoiled && 653 (dcr > 0 || dcw > 0 || dce > 0)) 654 return (ENXIO); 655 656 /* 657 * Figure out what counts the provider would have had, if this 658 * consumer had (r0w0e0) at this time. 659 */ 660 pr = pp->acr - cp->acr; 661 pw = pp->acw - cp->acw; 662 pe = pp->ace - cp->ace; 663 664 g_trace(G_T_ACCESS, 665 "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)", 666 dcr, dcw, dce, 667 cp->acr, cp->acw, cp->ace, 668 pp->acr, pp->acw, pp->ace, 669 pp, pp->name); 670 671 /* If foot-shooting is enabled, any open on rank#1 is OK */ 672 if ((g_debugflags & 16) && pp->geom->rank == 1) 673 ; 674 /* If we try exclusive but already write: fail */ 675 else if (dce > 0 && pw > 0) 676 return (EPERM); 677 /* If we try write but already exclusive: fail */ 678 else if (dcw > 0 && pe > 0) 679 return (EPERM); 680 /* If we try to open more but provider is error'ed: fail */ 681 else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0) 682 return (pp->error); 683 684 /* Ok then... */ 685 686 error = pp->geom->access(pp, dcr, dcw, dce); 687 KASSERT(dcr > 0 || dcw > 0 || dce > 0 || error == 0, 688 ("Geom provider %s::%s failed closing ->access()", 689 pp->geom->class->name, pp->name)); 690 if (!error) { 691 /* 692 * If we open first write, spoil any partner consumers. 693 * If we close last write, trigger re-taste. 694 */ 695 if (pp->acw == 0 && dcw != 0) 696 g_spoil(pp, cp); 697 else if (pp->acw != 0 && pp->acw == -dcw && 698 !(pp->geom->flags & G_GEOM_WITHER)) 699 g_post_event(g_new_provider_event, pp, M_WAITOK, 700 pp, NULL); 701 702 pp->acr += dcr; 703 pp->acw += dcw; 704 pp->ace += dce; 705 cp->acr += dcr; 706 cp->acw += dcw; 707 cp->ace += dce; 708 if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0) 709 KASSERT(pp->sectorsize > 0, 710 ("Provider %s lacks sectorsize", pp->name)); 711 } 712 return (error); 713 } 714 715 int 716 g_handleattr_int(struct bio *bp, const char *attribute, int val) 717 { 718 719 return (g_handleattr(bp, attribute, &val, sizeof val)); 720 } 721 722 int 723 g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val) 724 { 725 726 return (g_handleattr(bp, attribute, &val, sizeof val)); 727 } 728 729 int 730 g_handleattr(struct bio *bp, const char *attribute, void *val, int len) 731 { 732 int error; 733 734 if (strcmp(bp->bio_attribute, attribute)) 735 return (0); 736 if (bp->bio_length != len) { 737 printf("bio_length %jd len %d -> EFAULT\n", 738 (intmax_t)bp->bio_length, len); 739 error = EFAULT; 740 } else { 741 error = 0; 742 bcopy(val, bp->bio_data, len); 743 bp->bio_completed = len; 744 } 745 g_io_deliver(bp, error); 746 return (1); 747 } 748 749 int 750 g_std_access(struct g_provider *pp, 751 int dr __unused, int dw __unused, int de __unused) 752 { 753 754 g_topology_assert(); 755 G_VALID_PROVIDER(pp); 756 return (0); 757 } 758 759 void 760 g_std_done(struct bio *bp) 761 { 762 struct bio *bp2; 763 764 bp2 = bp->bio_parent; 765 if (bp2->bio_error == 0) 766 bp2->bio_error = bp->bio_error; 767 bp2->bio_completed += bp->bio_completed; 768 g_destroy_bio(bp); 769 bp2->bio_inbed++; 770 if (bp2->bio_children == bp2->bio_inbed) 771 g_io_deliver(bp2, bp2->bio_error); 772 } 773 774 /* XXX: maybe this is only g_slice_spoiled */ 775 776 void 777 g_std_spoiled(struct g_consumer *cp) 778 { 779 struct g_geom *gp; 780 struct g_provider *pp; 781 782 g_topology_assert(); 783 G_VALID_CONSUMER(cp); 784 g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp); 785 g_detach(cp); 786 gp = cp->geom; 787 LIST_FOREACH(pp, &gp->provider, provider) 788 g_orphan_provider(pp, ENXIO); 789 g_destroy_consumer(cp); 790 if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer)) 791 g_destroy_geom(gp); 792 else 793 gp->flags |= G_GEOM_WITHER; 794 } 795 796 /* 797 * Spoiling happens when a provider is opened for writing, but consumers 798 * which are configured by in-band data are attached (slicers for instance). 799 * Since the write might potentially change the in-band data, such consumers 800 * need to re-evaluate their existence after the writing session closes. 801 * We do this by (offering to) tear them down when the open for write happens 802 * in return for a re-taste when it closes again. 803 * Together with the fact that such consumers grab an 'e' bit whenever they 804 * are open, regardless of mode, this ends up DTRT. 805 */ 806 807 static void 808 g_spoil_event(void *arg, int flag) 809 { 810 struct g_provider *pp; 811 struct g_consumer *cp, *cp2; 812 813 g_topology_assert(); 814 if (flag == EV_CANCEL) 815 return; 816 pp = arg; 817 G_VALID_PROVIDER(pp); 818 for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) { 819 cp2 = LIST_NEXT(cp, consumers); 820 if (!cp->spoiled) 821 continue; 822 cp->spoiled = 0; 823 if (cp->geom->spoiled == NULL) 824 continue; 825 cp->geom->spoiled(cp); 826 g_topology_assert(); 827 } 828 } 829 830 void 831 g_spoil(struct g_provider *pp, struct g_consumer *cp) 832 { 833 struct g_consumer *cp2; 834 835 g_topology_assert(); 836 G_VALID_PROVIDER(pp); 837 G_VALID_CONSUMER(cp); 838 839 LIST_FOREACH(cp2, &pp->consumers, consumers) { 840 if (cp2 == cp) 841 continue; 842 /* 843 KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr)); 844 KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw)); 845 */ 846 KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace)); 847 cp2->spoiled++; 848 } 849 g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL); 850 } 851 852 int 853 g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len) 854 { 855 int error, i; 856 857 i = len; 858 error = g_io_getattr(attr, cp, &i, var); 859 if (error) 860 return (error); 861 if (i != len) 862 return (EINVAL); 863 return (0); 864 } 865 866 #ifdef DIAGNOSTIC 867 /* 868 * This function walks (topologically unsafely) the mesh and return a 869 * non-zero integer if it finds the argument pointer is an object. 870 * The return value indicates which type of object it is belived to be. 871 * If topology is not locked, this function is potentially dangerous, 872 * but since it is for debugging purposes and can be useful for instance 873 * from DDB, we do not assert topology lock is held. 874 */ 875 int 876 g_valid_obj(void const *ptr) 877 { 878 struct g_class *mp; 879 struct g_geom *gp; 880 struct g_consumer *cp; 881 struct g_provider *pp; 882 883 LIST_FOREACH(mp, &g_classes, class) { 884 if (ptr == mp) 885 return (1); 886 LIST_FOREACH(gp, &mp->geom, geom) { 887 if (ptr == gp) 888 return (2); 889 LIST_FOREACH(cp, &gp->consumer, consumer) 890 if (ptr == cp) 891 return (3); 892 LIST_FOREACH(pp, &gp->provider, provider) 893 if (ptr == pp) 894 return (4); 895 } 896 } 897 return(0); 898 } 899 #endif
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