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