sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
  23  * All rights reserved.
  24  */
  25
  26 #include <sys/zfs_context.h>
  27 #include <sys/param.h>
  28 #include <sys/kernel.h>
  29 #include <sys/bio.h>
  30 #include <sys/disk.h>
  31 #include <sys/spa.h>
  32 #include <sys/vdev_impl.h>
  33 #include <sys/fs/zfs.h>
  34 #include <sys/zio.h>
  35 #include <geom/geom.h>
  36 #include <geom/geom_int.h>
  37
  38 /*
  39  * Virtual device vector for GEOM.
  40  */
  41
  42 struct g_class zfs_vdev_class = {
  43         .name = "ZFS::VDEV",
  44         .version = G_VERSION,
  45 };
  46
  47 DECLARE_GEOM_CLASS(zfs_vdev_class, zfs_vdev);
  48
  49 typedef struct vdev_geom_ctx {
  50         struct g_consumer *gc_consumer;
  51         int gc_state;
  52         struct bio_queue_head gc_queue;
  53         struct mtx gc_queue_mtx;
  54 } vdev_geom_ctx_t;
  55
  56 static void
  57 vdev_geom_release(vdev_t *vd)
  58 {
  59         vdev_geom_ctx_t *ctx;
  60
  61         ctx = vd->vdev_tsd;
  62         vd->vdev_tsd = NULL;
  63
  64         mtx_lock(&ctx->gc_queue_mtx);
  65         ctx->gc_state = 1;
  66         wakeup_one(&ctx->gc_queue);
  67         while (ctx->gc_state != 2)
  68                 msleep(&ctx->gc_state, &ctx->gc_queue_mtx, 0, "vgeom:w", 0);
  69         mtx_unlock(&ctx->gc_queue_mtx);
  70         mtx_destroy(&ctx->gc_queue_mtx);
  71         kmem_free(ctx, sizeof(*ctx));
  72 }
  73
  74 static void
  75 vdev_geom_orphan(struct g_consumer *cp)
  76 {
  77         struct g_geom *gp;
  78         vdev_t *vd;
  79         int error;
  80
  81         g_topology_assert();
  82
  83         vd = cp->private;
  84         gp = cp->geom;
  85         error = cp->provider->error;
  86
  87         ZFS_LOG(1, "Closing access to %s.", cp->provider->name);
  88         if (cp->acr + cp->acw + cp->ace > 0)
  89                 g_access(cp, -cp->acr, -cp->acw, -cp->ace);
  90         ZFS_LOG(1, "Destroyed consumer to %s.", cp->provider->name);
  91         g_detach(cp);
  92         g_destroy_consumer(cp);
  93         /* Destroy geom if there are no consumers left. */
  94         if (LIST_EMPTY(&gp->consumer)) {
  95                 ZFS_LOG(1, "Destroyed geom %s.", gp->name);
  96                 g_wither_geom(gp, error);
  97         }
  98         vdev_geom_release(vd);
  99
 100         vd->vdev_remove_wanted = B_TRUE;
 101         spa_async_request(vd->vdev_spa, SPA_ASYNC_REMOVE);
 102 }
 103
 104 static struct g_consumer *
 105 vdev_geom_attach(struct g_provider *pp, int write)
 106 {
 107         struct g_geom *gp;
 108         struct g_consumer *cp;
 109
 110         g_topology_assert();
 111
 112         ZFS_LOG(1, "Attaching to %s.", pp->name);
 113         /* Do we have geom already? No? Create one. */
 114         LIST_FOREACH(gp, &zfs_vdev_class.geom, geom) {
 115                 if (gp->flags & G_GEOM_WITHER)
 116                         continue;
 117                 if (strcmp(gp->name, "zfs::vdev") != 0)
 118                         continue;
 119                 break;
 120         }
 121         if (gp == NULL) {
 122                 gp = g_new_geomf(&zfs_vdev_class, "zfs::vdev");
 123                 gp->orphan = vdev_geom_orphan;
 124                 cp = g_new_consumer(gp);
 125                 if (g_attach(cp, pp) != 0) {
 126                         g_wither_geom(gp, ENXIO);
 127                         return (NULL);
 128                 }
 129                 if (g_access(cp, 1, write, 1) != 0) {
 130                         g_wither_geom(gp, ENXIO);
 131                         return (NULL);
 132                 }
 133                 ZFS_LOG(1, "Created geom and consumer for %s.", pp->name);
 134         } else {
 135                 /* Check if we are already connected to this provider. */
 136                 LIST_FOREACH(cp, &gp->consumer, consumer) {
 137                         if (cp->provider == pp) {
 138                                 ZFS_LOG(1, "Found consumer for %s.", pp->name);
 139                                 break;
 140                         }
 141                 }
 142                 if (cp == NULL) {
 143                         cp = g_new_consumer(gp);
 144                         if (g_attach(cp, pp) != 0) {
 145                                 g_destroy_consumer(cp);
 146                                 return (NULL);
 147                         }
 148                         if (g_access(cp, 1, write, 1) != 0) {
 149                                 g_detach(cp);
 150                                 g_destroy_consumer(cp);
 151                                 return (NULL);
 152                         }
 153                         ZFS_LOG(1, "Created consumer for %s.", pp->name);
 154                 } else {
 155                         if (g_access(cp, 1, cp->acw > 0 ? 0 : write, 1) != 0)
 156                                 return (NULL);
 157                         ZFS_LOG(1, "Used existing consumer for %s.", pp->name);
 158                 }
 159         }
 160         return (cp);
 161 }
 162
 163 static void
 164 vdev_geom_detach(void *arg, int flag __unused)
 165 {
 166         struct g_geom *gp;
 167         struct g_consumer *cp;
 168
 169         g_topology_assert();
 170         cp = arg;
 171         gp = cp->geom;
 172
 173         ZFS_LOG(1, "Closing access to %s.", cp->provider->name);
 174         g_access(cp, -1, 0, -1);
 175         /* Destroy consumer on last close. */
 176         if (cp->acr == 0 && cp->ace == 0) {
 177                 ZFS_LOG(1, "Destroyed consumer to %s.", cp->provider->name);
 178                 if (cp->acw > 0)
 179                         g_access(cp, 0, -cp->acw, 0);
 180                 g_detach(cp);
 181                 g_destroy_consumer(cp);
 182         }
 183         /* Destroy geom if there are no consumers left. */
 184         if (LIST_EMPTY(&gp->consumer)) {
 185                 ZFS_LOG(1, "Destroyed geom %s.", gp->name);
 186                 g_wither_geom(gp, ENXIO);
 187         }
 188 }
 189
 190 static void
 191 vdev_geom_worker(void *arg)
 192 {
 193         vdev_geom_ctx_t *ctx;
 194         zio_t *zio;
 195         struct bio *bp;
 196
 197         thread_lock(curthread);
 198         sched_prio(curthread, PRIBIO);
 199         thread_unlock(curthread);
 200
 201         ctx = arg;
 202         for (;;) {
 203                 mtx_lock(&ctx->gc_queue_mtx);
 204                 bp = bioq_takefirst(&ctx->gc_queue);
 205                 if (bp == NULL) {
 206                         if (ctx->gc_state == 1) {
 207                                 ctx->gc_state = 2;
 208                                 wakeup_one(&ctx->gc_state);
 209                                 mtx_unlock(&ctx->gc_queue_mtx);
 210                                 kthread_exit();
 211                         }
 212                         msleep(&ctx->gc_queue, &ctx->gc_queue_mtx,
 213                             PRIBIO | PDROP, "vgeom:io", 0);
 214                         continue;
 215                 }
 216                 mtx_unlock(&ctx->gc_queue_mtx);
 217                 zio = bp->bio_caller1;
 218                 zio->io_error = bp->bio_error;
 219                 if (bp->bio_cmd == BIO_FLUSH && bp->bio_error == ENOTSUP) {
 220                         vdev_t *vd;
 221
 222                         /*
 223                          * If we get ENOTSUP, we know that no future
 224                          * attempts will ever succeed.  In this case we
 225                          * set a persistent bit so that we don't bother
 226                          * with the ioctl in the future.
 227                          */
 228                         vd = zio->io_vd;
 229                         vd->vdev_nowritecache = B_TRUE;
 230                 }
 231                 g_destroy_bio(bp);
 232                 zio_interrupt(zio);
 233         }
 234 }
 235
 236 static uint64_t
 237 nvlist_get_guid(nvlist_t *list)
 238 {
 239         nvpair_t *elem = NULL;
 240         uint64_t value;
 241
 242         while ((elem = nvlist_next_nvpair(list, elem)) != NULL) {
 243                 if (nvpair_type(elem) == DATA_TYPE_UINT64 &&
 244                     strcmp(nvpair_name(elem), "guid") == 0) {
 245                         VERIFY(nvpair_value_uint64(elem, &value) == 0);
 246                         return (value);
 247                 }
 248         }
 249         return (0);
 250 }
 251
 252 static int
 253 vdev_geom_io(struct g_consumer *cp, int cmd, void *data, off_t offset, off_t size)
 254 {
 255         struct bio *bp;
 256         u_char *p;
 257         off_t off;
 258         int error;
 259
 260         ASSERT((offset % cp->provider->sectorsize) == 0);
 261         ASSERT((size % cp->provider->sectorsize) == 0);
 262
 263         bp = g_alloc_bio();
 264         off = offset;
 265         offset += size;
 266         p = data;
 267         error = 0;
 268
 269         for (; off < offset; off += MAXPHYS, p += MAXPHYS, size -= MAXPHYS) {
 270                 bzero(bp, sizeof(*bp));
 271                 bp->bio_cmd = cmd;
 272                 bp->bio_done = NULL;
 273                 bp->bio_offset = off;
 274                 bp->bio_length = MIN(size, MAXPHYS);
 275                 bp->bio_data = p;
 276                 g_io_request(bp, cp);
 277                 error = biowait(bp, "vdev_geom_io");
 278                 if (error != 0)
 279                         break;
 280         }
 281
 282         g_destroy_bio(bp);
 283         return (error);
 284 }
 285
 286 static uint64_t
 287 vdev_geom_read_guid(struct g_consumer *cp)
 288 {
 289         struct g_provider *pp;
 290         vdev_label_t *label;
 291         char *p, *buf;
 292         size_t buflen;
 293         uint64_t psize;
 294         off_t offset, size;
 295         uint64_t guid;
 296         int error, l, len;
 297
 298         g_topology_assert_not();
 299
 300         pp = cp->provider;
 301
 302         psize = pp->mediasize;
 303         psize = P2ALIGN(psize, (uint64_t)sizeof(vdev_label_t));
 304
 305         size = sizeof(*label) + pp->sectorsize -
 306             ((sizeof(*label) - 1) % pp->sectorsize) - 1;
 307
 308         guid = 0;
 309         label = kmem_alloc(size, KM_SLEEP);
 310         buflen = sizeof(label->vl_vdev_phys.vp_nvlist);
 311
 312         for (l = 0; l < VDEV_LABELS; l++) {
 313                 nvlist_t *config = NULL;
 314
 315                 offset = vdev_label_offset(psize, l, 0);
 316                 if ((offset % pp->sectorsize) != 0)
 317                         continue;
 318
 319                 error = vdev_geom_io(cp, BIO_READ, label, offset, size);
 320                 if (error != 0)
 321                         continue;
 322                 buf = label->vl_vdev_phys.vp_nvlist;
 323
 324                 if (nvlist_unpack(buf, buflen, &config, 0) != 0)
 325                         continue;
 326
 327                 guid = nvlist_get_guid(config);
 328                 nvlist_free(config);
 329                 if (guid != 0)
 330                         break;
 331         }
 332
 333         kmem_free(label, size);
 334         if (guid != 0)
 335                 ZFS_LOG(1, "guid for %s is %ju", pp->name, (uintmax_t)guid);
 336         return (guid);
 337 }
 338
 339 struct vdev_geom_find {
 340         uint64_t guid;
 341         int write;
 342         struct g_consumer *cp;
 343 };
 344
 345 static void
 346 vdev_geom_taste_orphan(struct g_consumer *cp)
 347 {
 348
 349         KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
 350             cp->provider->name));
 351 }
 352
 353 static void
 354 vdev_geom_attach_by_guid_event(void *arg, int flags __unused)
 355 {
 356         struct vdev_geom_find *ap;
 357         struct g_class *mp;
 358         struct g_geom *gp, *zgp;
 359         struct g_provider *pp;
 360         struct g_consumer *zcp;
 361         uint64_t guid;
 362
 363         g_topology_assert();
 364
 365         ap = arg;
 366
 367         zgp = g_new_geomf(&zfs_vdev_class, "zfs::vdev::taste");
 368         /* This orphan function should be never called. */
 369         zgp->orphan = vdev_geom_taste_orphan;
 370         zcp = g_new_consumer(zgp);
 371
 372         LIST_FOREACH(mp, &g_classes, class) {
 373                 if (mp == &zfs_vdev_class)
 374                         continue;
 375                 LIST_FOREACH(gp, &mp->geom, geom) {
 376                         if (gp->flags & G_GEOM_WITHER)
 377                                 continue;
 378                         LIST_FOREACH(pp, &gp->provider, provider) {
 379                                 if (pp->flags & G_PF_WITHER)
 380                                         continue;
 381                                 g_attach(zcp, pp);
 382                                 if (g_access(zcp, 1, 0, 0) != 0) {
 383                                         g_detach(zcp);
 384                                         continue;
 385                                 }
 386                                 g_topology_unlock();
 387                                 guid = vdev_geom_read_guid(zcp);
 388                                 g_topology_lock();
 389                                 g_access(zcp, -1, 0, 0);
 390                                 g_detach(zcp);
 391                                 if (guid != ap->guid)
 392                                         continue;
 393                                 ap->cp = vdev_geom_attach(pp, ap->write);
 394                                 if (ap->cp == NULL) {
 395                                         printf("ZFS WARNING: Cannot open %s "
 396                                             "for writting.\n", pp->name);
 397                                         continue;
 398                                 }
 399                                 goto end;
 400                         }
 401                 }
 402         }
 403         ap->cp = NULL;
 404 end:
 405         g_destroy_consumer(zcp);
 406         g_destroy_geom(zgp);
 407 }
 408
 409 static struct g_consumer *
 410 vdev_geom_attach_by_guid(uint64_t guid, int write)
 411 {
 412         struct vdev_geom_find *ap;
 413         struct g_consumer *cp;
 414
 415         ap = kmem_zalloc(sizeof(*ap), KM_SLEEP);
 416         ap->guid = guid;
 417         ap->write = write;
 418         g_waitfor_event(vdev_geom_attach_by_guid_event, ap, M_WAITOK, NULL);
 419         cp = ap->cp;
 420         kmem_free(ap, sizeof(*ap));
 421         return (cp);
 422 }
 423
 424 static struct g_consumer *
 425 vdev_geom_open_by_guid(vdev_t *vd)
 426 {
 427         struct g_consumer *cp;
 428         char *buf;
 429         size_t len;
 430
 431         ZFS_LOG(1, "Searching by guid [%ju].", (uintmax_t)vd->vdev_guid);
 432         cp = vdev_geom_attach_by_guid(vd->vdev_guid, !!(spa_mode & FWRITE));
 433         if (cp != NULL) {
 434                 len = strlen(cp->provider->name) + strlen("/dev/") + 1;
 435                 buf = kmem_alloc(len, KM_SLEEP);
 436
 437                 snprintf(buf, len, "/dev/%s", cp->provider->name);
 438                 spa_strfree(vd->vdev_path);
 439                 vd->vdev_path = buf;
 440
 441                 ZFS_LOG(1, "Attach by guid [%ju] succeeded, provider %s.",
 442                     (uintmax_t)vd->vdev_guid, vd->vdev_path);
 443         } else {
 444                 ZFS_LOG(1, "Search by guid [%ju] failed.",
 445                     (uintmax_t)vd->vdev_guid);
 446         }
 447
 448         return (cp);
 449 }
 450
 451 static struct g_consumer *
 452 vdev_geom_open_by_path(vdev_t *vd, int check_guid)
 453 {
 454         struct g_provider *pp;
 455         struct g_consumer *cp;
 456         uint64_t guid;
 457
 458         cp = NULL;
 459         g_topology_lock();
 460         pp = g_provider_by_name(vd->vdev_path + sizeof("/dev/") - 1);
 461         if (pp != NULL) {
 462                 ZFS_LOG(1, "Found provider by name %s.", vd->vdev_path);
 463                 cp = vdev_geom_attach(pp, !!(spa_mode & FWRITE));
 464                 if (cp != NULL && check_guid) {
 465                         g_topology_unlock();
 466                         guid = vdev_geom_read_guid(cp);
 467                         g_topology_lock();
 468                         if (guid != vd->vdev_guid) {
 469                                 vdev_geom_detach(cp, 0);
 470                                 cp = NULL;
 471                                 ZFS_LOG(1, "guid mismatch for provider %s: "
 472                                     "%ju != %ju.", vd->vdev_path,
 473                                     (uintmax_t)vd->vdev_guid, (uintmax_t)guid);
 474                         } else {
 475                                 ZFS_LOG(1, "guid match for provider %s.",
 476                                     vd->vdev_path);
 477                         }
 478                 }
 479         }
 480         g_topology_unlock();
 481
 482         return (cp);
 483 }
 484
 485 static int
 486 vdev_geom_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
 487 {
 488         vdev_geom_ctx_t *ctx;
 489         struct g_provider *pp;
 490         struct g_consumer *cp;
 491         int owned;
 492
 493         /*
 494          * We must have a pathname, and it must be absolute.
 495          */
 496         if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
 497                 vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
 498                 return (EINVAL);
 499         }
 500
 501         vd->vdev_tsd = NULL;
 502
 503         if ((owned = mtx_owned(&Giant)))
 504                 mtx_unlock(&Giant);
 505         cp = vdev_geom_open_by_path(vd, 0);
 506         if (cp == NULL) {
 507                 /*
 508                  * The device at vd->vdev_path doesn't have the expected guid.
 509                  * The disks might have merely moved around so try all other
 510                  * geom providers to find one with the right guid.
 511                  */
 512                 cp = vdev_geom_open_by_guid(vd);
 513         }
 514         if (cp == NULL)
 515                 cp = vdev_geom_open_by_path(vd, 1);
 516         if (cp == NULL) {
 517                 ZFS_LOG(1, "Provider %s not found.", vd->vdev_path);
 518                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
 519                 if (owned)
 520                         mtx_lock(&Giant);
 521                 return (EACCES);
 522         }
 523         if (owned)
 524                 mtx_lock(&Giant);
 525
 526         cp->private = vd;
 527
 528         ctx = kmem_zalloc(sizeof(*ctx), KM_SLEEP);
 529         bioq_init(&ctx->gc_queue);
 530         mtx_init(&ctx->gc_queue_mtx, "zfs:vdev:geom:queue", NULL, MTX_DEF);
 531         ctx->gc_consumer = cp;
 532         ctx->gc_state = 0;
 533
 534         vd->vdev_tsd = ctx;
 535         pp = cp->provider;
 536
 537         kproc_kthread_add(vdev_geom_worker, ctx, &zfsproc, NULL, 0, 0,
 538             "zfskern", "vdev %s", pp->name);
 539
 540         /*
 541          * Determine the actual size of the device.
 542          */
 543         *psize = pp->mediasize;
 544
 545         /*
 546          * Determine the device's minimum transfer size.
 547          */
 548         *ashift = highbit(MAX(pp->sectorsize, SPA_MINBLOCKSIZE)) - 1;
 549
 550         /*
 551          * Clear the nowritecache bit, so that on a vdev_reopen() we will
 552          * try again.
 553          */
 554         vd->vdev_nowritecache = B_FALSE;
 555
 556         return (0);
 557 }
 558
 559 static void
 560 vdev_geom_close(vdev_t *vd)
 561 {
 562         vdev_geom_ctx_t *ctx;
 563         struct g_consumer *cp;
 564
 565         if ((ctx = vd->vdev_tsd) == NULL)
 566                 return;
 567         if ((cp = ctx->gc_consumer) == NULL)
 568                 return;
 569         vdev_geom_release(vd);
 570         g_post_event(vdev_geom_detach, cp, M_WAITOK, NULL);
 571 }
 572
 573 static void
 574 vdev_geom_io_intr(struct bio *bp)
 575 {
 576         vdev_geom_ctx_t *ctx;
 577         zio_t *zio;
 578
 579         zio = bp->bio_caller1;
 580         ctx = zio->io_vd->vdev_tsd;
 581
 582         if ((zio->io_error = bp->bio_error) == 0 && bp->bio_resid != 0)
 583                 zio->io_error = EIO;
 584
 585         mtx_lock(&ctx->gc_queue_mtx);
 586         bioq_insert_tail(&ctx->gc_queue, bp);
 587         wakeup_one(&ctx->gc_queue);
 588         mtx_unlock(&ctx->gc_queue_mtx);
 589 }
 590
 591 static int
 592 vdev_geom_io_start(zio_t *zio)
 593 {
 594         vdev_t *vd;
 595         vdev_geom_ctx_t *ctx;
 596         struct g_consumer *cp;
 597         struct bio *bp;
 598         int error;
 599
 600         cp = NULL;
 601
 602         vd = zio->io_vd;
 603         ctx = vd->vdev_tsd;
 604         if (ctx != NULL)
 605                 cp = ctx->gc_consumer;
 606
 607         if (zio->io_type == ZIO_TYPE_IOCTL) {
 608                 /* XXPOLICY */
 609                 if (!vdev_readable(vd)) {
 610                         zio->io_error = ENXIO;
 611                         return (ZIO_PIPELINE_CONTINUE);
 612                 }
 613
 614                 switch (zio->io_cmd) {
 615
 616                 case DKIOCFLUSHWRITECACHE:
 617
 618                         if (zfs_nocacheflush)
 619                                 break;
 620
 621                         if (vd->vdev_nowritecache) {
 622                                 zio->io_error = ENOTSUP;
 623                                 break;
 624                         }
 625
 626                         goto sendreq;
 627                 default:
 628                         zio->io_error = ENOTSUP;
 629                 }
 630
 631                 return (ZIO_PIPELINE_CONTINUE);
 632         }
 633 sendreq:
 634         if (cp == NULL) {
 635                 zio->io_error = ENXIO;
 636                 return (ZIO_PIPELINE_CONTINUE);
 637         }
 638         bp = g_alloc_bio();
 639         bp->bio_caller1 = zio;
 640         switch (zio->io_type) {
 641         case ZIO_TYPE_READ:
 642         case ZIO_TYPE_WRITE:
 643                 bp->bio_cmd = zio->io_type == ZIO_TYPE_READ ? BIO_READ : BIO_WRITE;
 644                 bp->bio_data = zio->io_data;
 645                 bp->bio_offset = zio->io_offset;
 646                 bp->bio_length = zio->io_size;
 647                 break;
 648         case ZIO_TYPE_IOCTL:
 649                 bp->bio_cmd = BIO_FLUSH;
 650                 bp->bio_data = NULL;
 651                 bp->bio_offset = cp->provider->mediasize;
 652                 bp->bio_length = 0;
 653                 break;
 654         }
 655         bp->bio_done = vdev_geom_io_intr;
 656
 657         g_io_request(bp, cp);
 658
 659         return (ZIO_PIPELINE_STOP);
 660 }
 661
 662 static void
 663 vdev_geom_io_done(zio_t *zio)
 664 {
 665 }
 666
 667 vdev_ops_t vdev_geom_ops = {
 668         vdev_geom_open,
 669         vdev_geom_close,
 670         vdev_default_asize,
 671         vdev_geom_io_start,
 672         vdev_geom_io_done,
 673         NULL,
 674         VDEV_TYPE_DISK,         /* name of this vdev type */
 675         B_TRUE                  /* leaf vdev */
 676 };