g_mountver.c revision 221451
1/*- 2 * Copyright (c) 2010 Edward Tomasz Napierala <trasz@FreeBSD.org> 3 * Copyright (c) 2004-2006 Pawel Jakub Dawidek <pjd@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include <sys/cdefs.h> 29__FBSDID("$FreeBSD: head/sys/geom/mountver/g_mountver.c 221451 2011-05-04 18:17:21Z ae $"); 30 31#include <sys/param.h> 32#include <sys/systm.h> 33#include <sys/kernel.h> 34#include <sys/module.h> 35#include <sys/lock.h> 36#include <sys/mutex.h> 37#include <sys/bio.h> 38#include <sys/disk.h> 39#include <sys/sysctl.h> 40#include <sys/malloc.h> 41#include <sys/eventhandler.h> 42#include <geom/geom.h> 43#include <geom/mountver/g_mountver.h> 44 45 46SYSCTL_DECL(_kern_geom); 47SYSCTL_NODE(_kern_geom, OID_AUTO, mountver, CTLFLAG_RW, 48 0, "GEOM_MOUNTVER stuff"); 49static u_int g_mountver_debug = 0; 50static u_int g_mountver_check_ident = 1; 51SYSCTL_UINT(_kern_geom_mountver, OID_AUTO, debug, CTLFLAG_RW, 52 &g_mountver_debug, 0, "Debug level"); 53SYSCTL_UINT(_kern_geom_mountver, OID_AUTO, check_ident, CTLFLAG_RW, 54 &g_mountver_check_ident, 0, "Check disk ident when reattaching"); 55 56static eventhandler_tag g_mountver_pre_sync = NULL; 57 58static void g_mountver_queue(struct bio *bp); 59static void g_mountver_orphan(struct g_consumer *cp); 60static int g_mountver_destroy(struct g_geom *gp, boolean_t force); 61static g_taste_t g_mountver_taste; 62static int g_mountver_destroy_geom(struct gctl_req *req, struct g_class *mp, 63 struct g_geom *gp); 64static void g_mountver_config(struct gctl_req *req, struct g_class *mp, 65 const char *verb); 66static void g_mountver_dumpconf(struct sbuf *sb, const char *indent, 67 struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp); 68static void g_mountver_init(struct g_class *mp); 69static void g_mountver_fini(struct g_class *mp); 70 71struct g_class g_mountver_class = { 72 .name = G_MOUNTVER_CLASS_NAME, 73 .version = G_VERSION, 74 .ctlreq = g_mountver_config, 75 .taste = g_mountver_taste, 76 .destroy_geom = g_mountver_destroy_geom, 77 .init = g_mountver_init, 78 .fini = g_mountver_fini 79}; 80 81static void 82g_mountver_done(struct bio *bp) 83{ 84 struct g_geom *gp; 85 struct bio *pbp; 86 87 if (bp->bio_error != ENXIO) { 88 g_std_done(bp); 89 return; 90 } 91 92 /* 93 * When the device goes away, it's possible that few requests 94 * will be completed with ENXIO before g_mountver_orphan() 95 * gets called. To work around that, we have to queue requests 96 * that failed with ENXIO, in order to send them later. 97 */ 98 gp = bp->bio_from->geom; 99 100 pbp = bp->bio_parent; 101 KASSERT(pbp->bio_to == LIST_FIRST(&gp->provider), 102 ("parent request was for someone else")); 103 g_destroy_bio(bp); 104 pbp->bio_inbed++; 105 g_mountver_queue(pbp); 106} 107 108static void 109g_mountver_send(struct bio *bp) 110{ 111 struct g_geom *gp; 112 struct bio *cbp; 113 114 gp = bp->bio_to->geom; 115 116 cbp = g_clone_bio(bp); 117 if (cbp == NULL) { 118 g_io_deliver(bp, ENOMEM); 119 return; 120 } 121 122 cbp->bio_done = g_mountver_done; 123 g_io_request(cbp, LIST_FIRST(&gp->consumer)); 124} 125 126static void 127g_mountver_queue(struct bio *bp) 128{ 129 struct g_mountver_softc *sc; 130 struct g_geom *gp; 131 132 gp = bp->bio_to->geom; 133 sc = gp->softc; 134 135 mtx_lock(&sc->sc_mtx); 136 TAILQ_INSERT_TAIL(&sc->sc_queue, bp, bio_queue); 137 mtx_unlock(&sc->sc_mtx); 138} 139 140static void 141g_mountver_send_queued(struct g_geom *gp) 142{ 143 struct g_mountver_softc *sc; 144 struct bio *bp; 145 146 sc = gp->softc; 147 148 mtx_lock(&sc->sc_mtx); 149 while ((bp = TAILQ_FIRST(&sc->sc_queue)) != NULL) { 150 TAILQ_REMOVE(&sc->sc_queue, bp, bio_queue); 151 G_MOUNTVER_LOGREQ(bp, "Sending queued request."); 152 g_mountver_send(bp); 153 } 154 mtx_unlock(&sc->sc_mtx); 155} 156 157static void 158g_mountver_discard_queued(struct g_geom *gp) 159{ 160 struct g_mountver_softc *sc; 161 struct bio *bp; 162 163 sc = gp->softc; 164 165 mtx_lock(&sc->sc_mtx); 166 while ((bp = TAILQ_FIRST(&sc->sc_queue)) != NULL) { 167 TAILQ_REMOVE(&sc->sc_queue, bp, bio_queue); 168 G_MOUNTVER_LOGREQ(bp, "Discarding queued request."); 169 g_io_deliver(bp, ENXIO); 170 } 171 mtx_unlock(&sc->sc_mtx); 172} 173 174static void 175g_mountver_start(struct bio *bp) 176{ 177 struct g_mountver_softc *sc; 178 struct g_geom *gp; 179 180 gp = bp->bio_to->geom; 181 sc = gp->softc; 182 G_MOUNTVER_LOGREQ(bp, "Request received."); 183 184 /* 185 * It is possible that some bios were returned with ENXIO, even though 186 * orphaning didn't happen yet. In that case, queue all subsequent 187 * requests in order to maintain ordering. 188 */ 189 if (sc->sc_orphaned || !TAILQ_EMPTY(&sc->sc_queue)) { 190 G_MOUNTVER_LOGREQ(bp, "Queueing request."); 191 g_mountver_queue(bp); 192 if (!sc->sc_orphaned) 193 g_mountver_send_queued(gp); 194 } else { 195 G_MOUNTVER_LOGREQ(bp, "Sending request."); 196 g_mountver_send(bp); 197 } 198} 199 200static int 201g_mountver_access(struct g_provider *pp, int dr, int dw, int de) 202{ 203 struct g_mountver_softc *sc; 204 struct g_geom *gp; 205 struct g_consumer *cp; 206 207 g_topology_assert(); 208 209 gp = pp->geom; 210 cp = LIST_FIRST(&gp->consumer); 211 sc = gp->softc; 212 if (sc == NULL && dr <= 0 && dw <= 0 && de <= 0) 213 return (0); 214 KASSERT(sc != NULL, ("Trying to access withered provider \"%s\".", pp->name)); 215 216 sc->sc_access_r += dr; 217 sc->sc_access_w += dw; 218 sc->sc_access_e += de; 219 220 if (sc->sc_orphaned) 221 return (0); 222 223 return (g_access(cp, dr, dw, de)); 224} 225 226static int 227g_mountver_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp) 228{ 229 struct g_mountver_softc *sc; 230 struct g_geom *gp; 231 struct g_provider *newpp; 232 struct g_consumer *cp; 233 char name[64]; 234 int error; 235 int identsize = DISK_IDENT_SIZE; 236 237 g_topology_assert(); 238 239 gp = NULL; 240 newpp = NULL; 241 cp = NULL; 242 243 snprintf(name, sizeof(name), "%s%s", pp->name, G_MOUNTVER_SUFFIX); 244 LIST_FOREACH(gp, &mp->geom, geom) { 245 if (strcmp(gp->name, name) == 0) { 246 gctl_error(req, "Provider %s already exists.", name); 247 return (EEXIST); 248 } 249 } 250 gp = g_new_geomf(mp, name); 251 sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO); 252 mtx_init(&sc->sc_mtx, "gmountver", NULL, MTX_DEF); 253 TAILQ_INIT(&sc->sc_queue); 254 sc->sc_provider_name = strdup(pp->name, M_GEOM); 255 gp->softc = sc; 256 gp->start = g_mountver_start; 257 gp->orphan = g_mountver_orphan; 258 gp->access = g_mountver_access; 259 gp->dumpconf = g_mountver_dumpconf; 260 261 newpp = g_new_providerf(gp, gp->name); 262 newpp->mediasize = pp->mediasize; 263 newpp->sectorsize = pp->sectorsize; 264 265 cp = g_new_consumer(gp); 266 error = g_attach(cp, pp); 267 if (error != 0) { 268 gctl_error(req, "Cannot attach to provider %s.", pp->name); 269 goto fail; 270 } 271 error = g_access(cp, 1, 0, 0); 272 if (error != 0) { 273 gctl_error(req, "Cannot access provider %s.", pp->name); 274 goto fail; 275 } 276 error = g_io_getattr("GEOM::ident", cp, &identsize, sc->sc_ident); 277 g_access(cp, -1, 0, 0); 278 if (error != 0) { 279 if (g_mountver_check_ident) { 280 gctl_error(req, "Cannot get disk ident from %s; error = %d.", pp->name, error); 281 goto fail; 282 } 283 284 G_MOUNTVER_DEBUG(0, "Cannot get disk ident from %s; error = %d.", pp->name, error); 285 sc->sc_ident[0] = '\0'; 286 } 287 288 g_error_provider(newpp, 0); 289 G_MOUNTVER_DEBUG(0, "Device %s created.", gp->name); 290 return (0); 291fail: 292 g_free(sc->sc_provider_name); 293 if (cp->provider != NULL) 294 g_detach(cp); 295 g_destroy_consumer(cp); 296 g_destroy_provider(newpp); 297 g_free(gp->softc); 298 g_destroy_geom(gp); 299 return (error); 300} 301 302static int 303g_mountver_destroy(struct g_geom *gp, boolean_t force) 304{ 305 struct g_mountver_softc *sc; 306 struct g_provider *pp; 307 308 g_topology_assert(); 309 if (gp->softc == NULL) 310 return (ENXIO); 311 sc = gp->softc; 312 pp = LIST_FIRST(&gp->provider); 313 if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) { 314 if (force) { 315 G_MOUNTVER_DEBUG(0, "Device %s is still open, so it " 316 "can't be definitely removed.", pp->name); 317 } else { 318 G_MOUNTVER_DEBUG(1, "Device %s is still open (r%dw%de%d).", 319 pp->name, pp->acr, pp->acw, pp->ace); 320 return (EBUSY); 321 } 322 } else { 323 G_MOUNTVER_DEBUG(0, "Device %s removed.", gp->name); 324 } 325 if (pp != NULL) 326 g_orphan_provider(pp, ENXIO); 327 g_mountver_discard_queued(gp); 328 g_free(sc->sc_provider_name); 329 g_free(gp->softc); 330 gp->softc = NULL; 331 g_wither_geom(gp, ENXIO); 332 333 return (0); 334} 335 336static int 337g_mountver_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp) 338{ 339 340 return (g_mountver_destroy(gp, 0)); 341} 342 343static void 344g_mountver_ctl_create(struct gctl_req *req, struct g_class *mp) 345{ 346 struct g_provider *pp; 347 const char *name; 348 char param[16]; 349 int i, *nargs; 350 351 g_topology_assert(); 352 353 nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs)); 354 if (nargs == NULL) { 355 gctl_error(req, "No '%s' argument", "nargs"); 356 return; 357 } 358 if (*nargs <= 0) { 359 gctl_error(req, "Missing device(s)."); 360 return; 361 } 362 for (i = 0; i < *nargs; i++) { 363 snprintf(param, sizeof(param), "arg%d", i); 364 name = gctl_get_asciiparam(req, param); 365 if (name == NULL) { 366 gctl_error(req, "No 'arg%d' argument", i); 367 return; 368 } 369 if (strncmp(name, "/dev/", strlen("/dev/")) == 0) 370 name += strlen("/dev/"); 371 pp = g_provider_by_name(name); 372 if (pp == NULL) { 373 G_MOUNTVER_DEBUG(1, "Provider %s is invalid.", name); 374 gctl_error(req, "Provider %s is invalid.", name); 375 return; 376 } 377 if (g_mountver_create(req, mp, pp) != 0) 378 return; 379 } 380} 381 382static struct g_geom * 383g_mountver_find_geom(struct g_class *mp, const char *name) 384{ 385 struct g_geom *gp; 386 387 LIST_FOREACH(gp, &mp->geom, geom) { 388 if (strcmp(gp->name, name) == 0) 389 return (gp); 390 } 391 return (NULL); 392} 393 394static void 395g_mountver_ctl_destroy(struct gctl_req *req, struct g_class *mp) 396{ 397 int *nargs, *force, error, i; 398 struct g_geom *gp; 399 const char *name; 400 char param[16]; 401 402 g_topology_assert(); 403 404 nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs)); 405 if (nargs == NULL) { 406 gctl_error(req, "No '%s' argument", "nargs"); 407 return; 408 } 409 if (*nargs <= 0) { 410 gctl_error(req, "Missing device(s)."); 411 return; 412 } 413 force = gctl_get_paraml(req, "force", sizeof(*force)); 414 if (force == NULL) { 415 gctl_error(req, "No 'force' argument"); 416 return; 417 } 418 419 for (i = 0; i < *nargs; i++) { 420 snprintf(param, sizeof(param), "arg%d", i); 421 name = gctl_get_asciiparam(req, param); 422 if (name == NULL) { 423 gctl_error(req, "No 'arg%d' argument", i); 424 return; 425 } 426 if (strncmp(name, "/dev/", strlen("/dev/")) == 0) 427 name += strlen("/dev/"); 428 gp = g_mountver_find_geom(mp, name); 429 if (gp == NULL) { 430 G_MOUNTVER_DEBUG(1, "Device %s is invalid.", name); 431 gctl_error(req, "Device %s is invalid.", name); 432 return; 433 } 434 error = g_mountver_destroy(gp, *force); 435 if (error != 0) { 436 gctl_error(req, "Cannot destroy device %s (error=%d).", 437 gp->name, error); 438 return; 439 } 440 } 441} 442 443static void 444g_mountver_orphan(struct g_consumer *cp) 445{ 446 struct g_mountver_softc *sc; 447 448 g_topology_assert(); 449 450 sc = cp->geom->softc; 451 sc->sc_orphaned = 1; 452 if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0) 453 g_access(cp, -cp->acr, -cp->acw, -cp->ace); 454 g_detach(cp); 455 G_MOUNTVER_DEBUG(0, "%s is offline. Mount verification in progress.", sc->sc_provider_name); 456} 457 458static int 459g_mountver_ident_matches(struct g_geom *gp) 460{ 461 struct g_consumer *cp; 462 struct g_mountver_softc *sc; 463 char ident[DISK_IDENT_SIZE]; 464 int error, identsize = DISK_IDENT_SIZE; 465 466 sc = gp->softc; 467 cp = LIST_FIRST(&gp->consumer); 468 469 if (g_mountver_check_ident == 0) 470 return (0); 471 472 error = g_access(cp, 1, 0, 0); 473 if (error != 0) { 474 G_MOUNTVER_DEBUG(0, "Cannot access %s; " 475 "not attaching; error = %d.", gp->name, error); 476 return (1); 477 } 478 error = g_io_getattr("GEOM::ident", cp, &identsize, ident); 479 g_access(cp, -1, 0, 0); 480 if (error != 0) { 481 G_MOUNTVER_DEBUG(0, "Cannot get disk ident for %s; " 482 "not attaching; error = %d.", gp->name, error); 483 return (1); 484 } 485 if (strcmp(ident, sc->sc_ident) != 0) { 486 G_MOUNTVER_DEBUG(1, "Disk ident for %s (\"%s\") is different " 487 "from expected \"%s\", not attaching.", gp->name, ident, 488 sc->sc_ident); 489 return (1); 490 } 491 492 return (0); 493} 494 495static struct g_geom * 496g_mountver_taste(struct g_class *mp, struct g_provider *pp, int flags __unused) 497{ 498 struct g_mountver_softc *sc; 499 struct g_consumer *cp; 500 struct g_geom *gp; 501 int error; 502 503 g_topology_assert(); 504 g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name); 505 G_MOUNTVER_DEBUG(2, "Tasting %s.", pp->name); 506 507 /* 508 * Let's check if device already exists. 509 */ 510 LIST_FOREACH(gp, &mp->geom, geom) { 511 sc = gp->softc; 512 if (sc == NULL) 513 continue; 514 515 /* Already attached? */ 516 if (pp == LIST_FIRST(&gp->provider)) 517 return (NULL); 518 519 if (sc->sc_orphaned && strcmp(pp->name, sc->sc_provider_name) == 0) 520 break; 521 } 522 if (gp == NULL) 523 return (NULL); 524 525 cp = LIST_FIRST(&gp->consumer); 526 g_attach(cp, pp); 527 error = g_mountver_ident_matches(gp); 528 if (error != 0) { 529 g_detach(cp); 530 return (NULL); 531 } 532 if (sc->sc_access_r > 0 || sc->sc_access_w > 0 || sc->sc_access_e > 0) { 533 error = g_access(cp, sc->sc_access_r, sc->sc_access_w, sc->sc_access_e); 534 if (error != 0) { 535 G_MOUNTVER_DEBUG(0, "Cannot access %s; error = %d.", pp->name, error); 536 g_detach(cp); 537 return (NULL); 538 } 539 } 540 g_mountver_send_queued(gp); 541 sc->sc_orphaned = 0; 542 G_MOUNTVER_DEBUG(0, "%s has completed mount verification.", sc->sc_provider_name); 543 544 return (gp); 545} 546 547static void 548g_mountver_config(struct gctl_req *req, struct g_class *mp, const char *verb) 549{ 550 uint32_t *version; 551 552 g_topology_assert(); 553 554 version = gctl_get_paraml(req, "version", sizeof(*version)); 555 if (version == NULL) { 556 gctl_error(req, "No '%s' argument.", "version"); 557 return; 558 } 559 if (*version != G_MOUNTVER_VERSION) { 560 gctl_error(req, "Userland and kernel parts are out of sync."); 561 return; 562 } 563 564 if (strcmp(verb, "create") == 0) { 565 g_mountver_ctl_create(req, mp); 566 return; 567 } else if (strcmp(verb, "destroy") == 0) { 568 g_mountver_ctl_destroy(req, mp); 569 return; 570 } 571 572 gctl_error(req, "Unknown verb."); 573} 574 575static void 576g_mountver_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, 577 struct g_consumer *cp, struct g_provider *pp) 578{ 579 struct g_mountver_softc *sc; 580 581 if (pp != NULL || cp != NULL) 582 return; 583 584 sc = gp->softc; 585 sbuf_printf(sb, "%s<State>%s</State>\n", indent, 586 sc->sc_orphaned ? "OFFLINE" : "ONLINE"); 587 sbuf_printf(sb, "%s<Provider-Name>%s</Provider-Name>\n", indent, sc->sc_provider_name); 588 sbuf_printf(sb, "%s<Disk-Ident>%s</Disk-Ident>\n", indent, sc->sc_ident); 589} 590 591static void 592g_mountver_shutdown_pre_sync(void *arg, int howto) 593{ 594 struct g_class *mp; 595 struct g_geom *gp, *gp2; 596 597 mp = arg; 598 DROP_GIANT(); 599 g_topology_lock(); 600 LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) 601 g_mountver_destroy(gp, 1); 602 g_topology_unlock(); 603 PICKUP_GIANT(); 604} 605 606static void 607g_mountver_init(struct g_class *mp) 608{ 609 610 g_mountver_pre_sync = EVENTHANDLER_REGISTER(shutdown_pre_sync, 611 g_mountver_shutdown_pre_sync, mp, SHUTDOWN_PRI_FIRST); 612 if (g_mountver_pre_sync == NULL) 613 G_MOUNTVER_DEBUG(0, "Warning! Cannot register shutdown event."); 614} 615 616static void 617g_mountver_fini(struct g_class *mp) 618{ 619 620 if (g_mountver_pre_sync != NULL) 621 EVENTHANDLER_DEREGISTER(shutdown_pre_sync, g_mountver_pre_sync); 622} 623 624DECLARE_GEOM_CLASS(g_mountver_class, g_mountver); 625