usr/src/uts/common/fs/zfs/vdev_disk.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 2010 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #include <sys/zfs_context.h>
  27 #include <sys/spa_impl.h>
  28 #include <sys/refcount.h>
  29 #include <sys/vdev_disk.h>
  30 #include <sys/vdev_impl.h>
  31 #include <sys/fs/zfs.h>
  32 #include <sys/zio.h>
  33 #include <sys/sunldi.h>
  34 #include <sys/fm/fs/zfs.h>
  35
  36 /*
  37  * Virtual device vector for disks.
  38  */
  39
  40 extern ldi_ident_t zfs_li;
  41
  42 typedef struct vdev_disk_buf {
  43         buf_t   vdb_buf;
  44         zio_t   *vdb_io;
  45 } vdev_disk_buf_t;
  46
  47 static void
  48 vdev_disk_hold(vdev_t *vd)
  49 {
  50         ddi_devid_t devid;
  51         char *minor;
  52
  53         ASSERT(spa_config_held(vd->vdev_spa, SCL_STATE, RW_WRITER));
  54
  55         /*
  56          * We must have a pathname, and it must be absolute.
  57          */
  58         if (vd->vdev_path == NULL || vd->vdev_path[0] != '/')
  59                 return;
  60
  61         /*
  62          * Only prefetch path and devid info if the device has
  63          * never been opened.
  64          */
  65         if (vd->vdev_tsd != NULL)
  66                 return;
  67
  68         if (vd->vdev_wholedisk == -1ULL) {
  69                 size_t len = strlen(vd->vdev_path) + 3;
  70                 char *buf = kmem_alloc(len, KM_SLEEP);
  71
  72                 (void) snprintf(buf, len, "%ss0", vd->vdev_path);
  73
  74                 (void) ldi_vp_from_name(buf, &vd->vdev_name_vp);
  75                 kmem_free(buf, len);
  76         }
  77
  78         if (vd->vdev_name_vp == NULL)
  79                 (void) ldi_vp_from_name(vd->vdev_path, &vd->vdev_name_vp);
  80
  81         if (vd->vdev_devid != NULL &&
  82             ddi_devid_str_decode(vd->vdev_devid, &devid, &minor) == 0) {
  83                 (void) ldi_vp_from_devid(devid, minor, &vd->vdev_devid_vp);
  84                 ddi_devid_str_free(minor);
  85                 ddi_devid_free(devid);
  86         }
  87 }
  88
  89 static void
  90 vdev_disk_rele(vdev_t *vd)
  91 {
  92         ASSERT(spa_config_held(vd->vdev_spa, SCL_STATE, RW_WRITER));
  93
  94         if (vd->vdev_name_vp) {
  95                 VN_RELE_ASYNC(vd->vdev_name_vp,
  96                     dsl_pool_vnrele_taskq(vd->vdev_spa->spa_dsl_pool));
  97                 vd->vdev_name_vp = NULL;
  98         }
  99         if (vd->vdev_devid_vp) {
 100                 VN_RELE_ASYNC(vd->vdev_devid_vp,
 101                     dsl_pool_vnrele_taskq(vd->vdev_spa->spa_dsl_pool));
 102                 vd->vdev_devid_vp = NULL;
 103         }
 104 }
 105
 106 static int
 107 vdev_disk_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
 108 {
 109         spa_t *spa = vd->vdev_spa;
 110         vdev_disk_t *dvd;
 111         struct dk_minfo dkm;
 112         int error;
 113         dev_t dev;
 114         int otyp;
 115
 116         /*
 117          * We must have a pathname, and it must be absolute.
 118          */
 119         if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
 120                 vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
 121                 return (EINVAL);
 122         }
 123
 124         /*
 125          * Reopen the device if it's not currently open. Otherwise,
 126          * just update the physical size of the device.
 127          */
 128         if (vd->vdev_tsd != NULL) {
 129                 ASSERT(vd->vdev_reopening);
 130                 dvd = vd->vdev_tsd;
 131                 goto skip_open;
 132         }
 133
 134         dvd = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_disk_t), KM_SLEEP);
 135
 136         /*
 137          * When opening a disk device, we want to preserve the user's original
 138          * intent.  We always want to open the device by the path the user gave
 139          * us, even if it is one of multiple paths to the save device.  But we
 140          * also want to be able to survive disks being removed/recabled.
 141          * Therefore the sequence of opening devices is:
 142          *
 143          * 1. Try opening the device by path.  For legacy pools without the
 144          *    'whole_disk' property, attempt to fix the path by appending 's0'.
 145          *
 146          * 2. If the devid of the device matches the stored value, return
 147          *    success.
 148          *
 149          * 3. Otherwise, the device may have moved.  Try opening the device
 150          *    by the devid instead.
 151          */
 152         if (vd->vdev_devid != NULL) {
 153                 if (ddi_devid_str_decode(vd->vdev_devid, &dvd->vd_devid,
 154                     &dvd->vd_minor) != 0) {
 155                         vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
 156                         return (EINVAL);
 157                 }
 158         }
 159
 160         error = EINVAL;         /* presume failure */
 161
 162         if (vd->vdev_path != NULL) {
 163                 ddi_devid_t devid;
 164
 165                 if (vd->vdev_wholedisk == -1ULL) {
 166                         size_t len = strlen(vd->vdev_path) + 3;
 167                         char *buf = kmem_alloc(len, KM_SLEEP);
 168                         ldi_handle_t lh;
 169
 170                         (void) snprintf(buf, len, "%ss0", vd->vdev_path);
 171
 172                         if (ldi_open_by_name(buf, spa_mode(spa), kcred,
 173                             &lh, zfs_li) == 0) {
 174                                 spa_strfree(vd->vdev_path);
 175                                 vd->vdev_path = buf;
 176                                 vd->vdev_wholedisk = 1ULL;
 177                                 (void) ldi_close(lh, spa_mode(spa), kcred);
 178                         } else {
 179                                 kmem_free(buf, len);
 180                         }
 181                 }
 182
 183                 error = ldi_open_by_name(vd->vdev_path, spa_mode(spa), kcred,
 184                     &dvd->vd_lh, zfs_li);
 185
 186                 /*
 187                  * Compare the devid to the stored value.
 188                  */
 189                 if (error == 0 && vd->vdev_devid != NULL &&
 190                     ldi_get_devid(dvd->vd_lh, &devid) == 0) {
 191                         if (ddi_devid_compare(devid, dvd->vd_devid) != 0) {
 192                                 error = EINVAL;
 193                                 (void) ldi_close(dvd->vd_lh, spa_mode(spa),
 194                                     kcred);
 195                                 dvd->vd_lh = NULL;
 196                         }
 197                         ddi_devid_free(devid);
 198                 }
 199
 200                 /*
 201                  * If we succeeded in opening the device, but 'vdev_wholedisk'
 202                  * is not yet set, then this must be a slice.
 203                  */
 204                 if (error == 0 && vd->vdev_wholedisk == -1ULL)
 205                         vd->vdev_wholedisk = 0;
 206         }
 207
 208         /*
 209          * If we were unable to open by path, or the devid check fails, open by
 210          * devid instead.
 211          */
 212         if (error != 0 && vd->vdev_devid != NULL)
 213                 error = ldi_open_by_devid(dvd->vd_devid, dvd->vd_minor,
 214                     spa_mode(spa), kcred, &dvd->vd_lh, zfs_li);
 215
 216         /*
 217          * If all else fails, then try opening by physical path (if available)
 218          * or the logical path (if we failed due to the devid check).  While not
 219          * as reliable as the devid, this will give us something, and the higher
 220          * level vdev validation will prevent us from opening the wrong device.
 221          */
 222         if (error) {
 223                 if (vd->vdev_physpath != NULL &&
 224                     (dev = ddi_pathname_to_dev_t(vd->vdev_physpath)) != NODEV)
 225                         error = ldi_open_by_dev(&dev, OTYP_BLK, spa_mode(spa),
 226                             kcred, &dvd->vd_lh, zfs_li);
 227
 228                 /*
 229                  * Note that we don't support the legacy auto-wholedisk support
 230                  * as above.  This hasn't been used in a very long time and we
 231                  * don't need to propagate its oddities to this edge condition.
 232                  */
 233                 if (error && vd->vdev_path != NULL)
 234                         error = ldi_open_by_name(vd->vdev_path, spa_mode(spa),
 235                             kcred, &dvd->vd_lh, zfs_li);
 236         }
 237
 238         if (error) {
 239                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
 240                 return (error);
 241         }
 242
 243         /*
 244          * Once a device is opened, verify that the physical device path (if
 245          * available) is up to date.
 246          */
 247         if (ldi_get_dev(dvd->vd_lh, &dev) == 0 &&
 248             ldi_get_otyp(dvd->vd_lh, &otyp) == 0) {
 249                 char *physpath, *minorname;
 250
 251                 physpath = kmem_alloc(MAXPATHLEN, KM_SLEEP);
 252                 minorname = NULL;
 253                 if (ddi_dev_pathname(dev, otyp, physpath) == 0 &&
 254                     ldi_get_minor_name(dvd->vd_lh, &minorname) == 0 &&
 255                     (vd->vdev_physpath == NULL ||
 256                     strcmp(vd->vdev_physpath, physpath) != 0)) {
 257                         if (vd->vdev_physpath)
 258                                 spa_strfree(vd->vdev_physpath);
 259                         (void) strlcat(physpath, ":", MAXPATHLEN);
 260                         (void) strlcat(physpath, minorname, MAXPATHLEN);
 261                         vd->vdev_physpath = spa_strdup(physpath);
 262                 }
 263                 if (minorname)
 264                         kmem_free(minorname, strlen(minorname) + 1);
 265                 kmem_free(physpath, MAXPATHLEN);
 266         }
 267
 268 skip_open:
 269         /*
 270          * Determine the actual size of the device.
 271          */
 272         if (ldi_get_size(dvd->vd_lh, psize) != 0) {
 273                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
 274                 return (EINVAL);
 275         }
 276
 277         /*
 278          * If we own the whole disk, try to enable disk write caching.
 279          * We ignore errors because it's OK if we can't do it.
 280          */
 281         if (vd->vdev_wholedisk == 1) {
 282                 int wce = 1;
 283                 (void) ldi_ioctl(dvd->vd_lh, DKIOCSETWCE, (intptr_t)&wce,
 284                     FKIOCTL, kcred, NULL);
 285         }
 286
 287         /*
 288          * Determine the device's minimum transfer size.
 289          * If the ioctl isn't supported, assume DEV_BSIZE.
 290          */
 291         if (ldi_ioctl(dvd->vd_lh, DKIOCGMEDIAINFO, (intptr_t)&dkm,
 292             FKIOCTL, kcred, NULL) != 0)
 293                 dkm.dki_lbsize = DEV_BSIZE;
 294
 295         *ashift = highbit(MAX(dkm.dki_lbsize, SPA_MINBLOCKSIZE)) - 1;
 296
 297         /*
 298          * Clear the nowritecache bit, so that on a vdev_reopen() we will
 299          * try again.
 300          */
 301         vd->vdev_nowritecache = B_FALSE;
 302
 303         return (0);
 304 }
 305
 306 static void
 307 vdev_disk_close(vdev_t *vd)
 308 {
 309         vdev_disk_t *dvd = vd->vdev_tsd;
 310
 311         if (vd->vdev_reopening || dvd == NULL)
 312                 return;
 313
 314         if (dvd->vd_minor != NULL)
 315                 ddi_devid_str_free(dvd->vd_minor);
 316
 317         if (dvd->vd_devid != NULL)
 318                 ddi_devid_free(dvd->vd_devid);
 319
 320         if (dvd->vd_lh != NULL)
 321                 (void) ldi_close(dvd->vd_lh, spa_mode(vd->vdev_spa), kcred);
 322
 323         kmem_free(dvd, sizeof (vdev_disk_t));
 324         vd->vdev_tsd = NULL;
 325 }
 326
 327 int
 328 vdev_disk_physio(ldi_handle_t vd_lh, caddr_t data, size_t size,
 329     uint64_t offset, int flags)
 330 {
 331         buf_t *bp;
 332         int error = 0;
 333
 334         if (vd_lh == NULL)
 335                 return (EINVAL);
 336
 337         ASSERT(flags & B_READ || flags & B_WRITE);
 338
 339         bp = getrbuf(KM_SLEEP);
 340         bp->b_flags = flags | B_BUSY | B_NOCACHE | B_FAILFAST;
 341         bp->b_bcount = size;
 342         bp->b_un.b_addr = (void *)data;
 343         bp->b_lblkno = lbtodb(offset);
 344         bp->b_bufsize = size;
 345
 346         error = ldi_strategy(vd_lh, bp);
 347         ASSERT(error == 0);
 348         if ((error = biowait(bp)) == 0 && bp->b_resid != 0)
 349                 error = EIO;
 350         freerbuf(bp);
 351
 352         return (error);
 353 }
 354
 355 static void
 356 vdev_disk_io_intr(buf_t *bp)
 357 {
 358         vdev_disk_buf_t *vdb = (vdev_disk_buf_t *)bp;
 359         zio_t *zio = vdb->vdb_io;
 360
 361         /*
 362          * The rest of the zio stack only deals with EIO, ECKSUM, and ENXIO.
 363          * Rather than teach the rest of the stack about other error
 364          * possibilities (EFAULT, etc), we normalize the error value here.
 365          */
 366         zio->io_error = (geterror(bp) != 0 ? EIO : 0);
 367
 368         if (zio->io_error == 0 && bp->b_resid != 0)
 369                 zio->io_error = EIO;
 370
 371         kmem_free(vdb, sizeof (vdev_disk_buf_t));
 372
 373         zio_interrupt(zio);
 374 }
 375
 376 static void
 377 vdev_disk_ioctl_free(zio_t *zio)
 378 {
 379         kmem_free(zio->io_vsd, sizeof (struct dk_callback));
 380 }
 381
 382 static const zio_vsd_ops_t vdev_disk_vsd_ops = {
 383         vdev_disk_ioctl_free,
 384         zio_vsd_default_cksum_report
 385 };
 386
 387 static void
 388 vdev_disk_ioctl_done(void *zio_arg, int error)
 389 {
 390         zio_t *zio = zio_arg;
 391
 392         zio->io_error = error;
 393
 394         zio_interrupt(zio);
 395 }
 396
 397 static int
 398 vdev_disk_io_start(zio_t *zio)
 399 {
 400         vdev_t *vd = zio->io_vd;
 401         vdev_disk_t *dvd = vd->vdev_tsd;
 402         vdev_disk_buf_t *vdb;
 403         struct dk_callback *dkc;
 404         buf_t *bp;
 405         int error;
 406
 407         if (zio->io_type == ZIO_TYPE_IOCTL) {
 408                 /* XXPOLICY */
 409                 if (!vdev_readable(vd)) {
 410                         zio->io_error = ENXIO;
 411                         return (ZIO_PIPELINE_CONTINUE);
 412                 }
 413
 414                 switch (zio->io_cmd) {
 415
 416                 case DKIOCFLUSHWRITECACHE:
 417
 418                         if (zfs_nocacheflush)
 419                                 break;
 420
 421                         if (vd->vdev_nowritecache) {
 422                                 zio->io_error = ENOTSUP;
 423                                 break;
 424                         }
 425
 426                         zio->io_vsd = dkc = kmem_alloc(sizeof (*dkc), KM_SLEEP);
 427                         zio->io_vsd_ops = &vdev_disk_vsd_ops;
 428
 429                         dkc->dkc_callback = vdev_disk_ioctl_done;
 430                         dkc->dkc_flag = FLUSH_VOLATILE;
 431                         dkc->dkc_cookie = zio;
 432
 433                         error = ldi_ioctl(dvd->vd_lh, zio->io_cmd,
 434                             (uintptr_t)dkc, FKIOCTL, kcred, NULL);
 435
 436                         if (error == 0) {
 437                                 /*
 438                                  * The ioctl will be done asychronously,
 439                                  * and will call vdev_disk_ioctl_done()
 440                                  * upon completion.
 441                                  */
 442                                 return (ZIO_PIPELINE_STOP);
 443                         }
 444
 445                         if (error == ENOTSUP || error == ENOTTY) {
 446                                 /*
 447                                  * If we get ENOTSUP or ENOTTY, we know that
 448                                  * no future attempts will ever succeed.
 449                                  * In this case we set a persistent bit so
 450                                  * that we don't bother with the ioctl in the
 451                                  * future.
 452                                  */
 453                                 vd->vdev_nowritecache = B_TRUE;
 454                         }
 455                         zio->io_error = error;
 456
 457                         break;
 458
 459                 default:
 460                         zio->io_error = ENOTSUP;
 461                 }
 462
 463                 return (ZIO_PIPELINE_CONTINUE);
 464         }
 465
 466         vdb = kmem_alloc(sizeof (vdev_disk_buf_t), KM_SLEEP);
 467
 468         vdb->vdb_io = zio;
 469         bp = &vdb->vdb_buf;
 470
 471         bioinit(bp);
 472         bp->b_flags = B_BUSY | B_NOCACHE |
 473             (zio->io_type == ZIO_TYPE_READ ? B_READ : B_WRITE);
 474         if (!(zio->io_flags & (ZIO_FLAG_IO_RETRY | ZIO_FLAG_TRYHARD)))
 475                 bp->b_flags |= B_FAILFAST;
 476         bp->b_bcount = zio->io_size;
 477         bp->b_un.b_addr = zio->io_data;
 478         bp->b_lblkno = lbtodb(zio->io_offset);
 479         bp->b_bufsize = zio->io_size;
 480         bp->b_iodone = (int (*)())vdev_disk_io_intr;
 481
 482         /* ldi_strategy() will return non-zero only on programming errors */
 483         VERIFY(ldi_strategy(dvd->vd_lh, bp) == 0);
 484
 485         return (ZIO_PIPELINE_STOP);
 486 }
 487
 488 static void
 489 vdev_disk_io_done(zio_t *zio)
 490 {
 491         vdev_t *vd = zio->io_vd;
 492
 493         /*
 494          * If the device returned EIO, then attempt a DKIOCSTATE ioctl to see if
 495          * the device has been removed.  If this is the case, then we trigger an
 496          * asynchronous removal of the device. Otherwise, probe the device and
 497          * make sure it's still accessible.
 498          */
 499         if (zio->io_error == EIO && !vd->vdev_remove_wanted) {
 500                 vdev_disk_t *dvd = vd->vdev_tsd;
 501                 int state = DKIO_NONE;
 502
 503                 if (ldi_ioctl(dvd->vd_lh, DKIOCSTATE, (intptr_t)&state,
 504                     FKIOCTL, kcred, NULL) == 0 && state != DKIO_INSERTED) {
 505                         /*
 506                          * We post the resource as soon as possible, instead of
 507                          * when the async removal actually happens, because the
 508                          * DE is using this information to discard previous I/O
 509                          * errors.
 510                          */
 511                         zfs_post_remove(zio->io_spa, vd);
 512                         vd->vdev_remove_wanted = B_TRUE;
 513                         spa_async_request(zio->io_spa, SPA_ASYNC_REMOVE);
 514                 }
 515         }
 516 }
 517
 518 vdev_ops_t vdev_disk_ops = {
 519         vdev_disk_open,
 520         vdev_disk_close,
 521         vdev_default_asize,
 522         vdev_disk_io_start,
 523         vdev_disk_io_done,
 524         NULL,
 525         vdev_disk_hold,
 526         vdev_disk_rele,
 527         VDEV_TYPE_DISK,         /* name of this vdev type */
 528         B_TRUE                  /* leaf vdev */
 529 };
 530
 531 /*
 532  * Given the root disk device devid or pathname, read the label from
 533  * the device, and construct a configuration nvlist.
 534  */
 535 int
 536 vdev_disk_read_rootlabel(char *devpath, char *devid, nvlist_t **config)
 537 {
 538         ldi_handle_t vd_lh;
 539         vdev_label_t *label;
 540         uint64_t s, size;
 541         int l;
 542         ddi_devid_t tmpdevid;
 543         int error = -1;
 544         char *minor_name;
 545
 546         /*
 547          * Read the device label and build the nvlist.
 548          */
 549         if (devid != NULL && ddi_devid_str_decode(devid, &tmpdevid,
 550             &minor_name) == 0) {
 551                 error = ldi_open_by_devid(tmpdevid, minor_name,
 552                     FREAD, kcred, &vd_lh, zfs_li);
 553                 ddi_devid_free(tmpdevid);
 554                 ddi_devid_str_free(minor_name);
 555         }
 556
 557         if (error && (error = ldi_open_by_name(devpath, FREAD, kcred, &vd_lh,
 558             zfs_li)))
 559                 return (error);
 560
 561         if (ldi_get_size(vd_lh, &s)) {
 562                 (void) ldi_close(vd_lh, FREAD, kcred);
 563                 return (EIO);
 564         }
 565
 566         size = P2ALIGN_TYPED(s, sizeof (vdev_label_t), uint64_t);
 567         label = kmem_alloc(sizeof (vdev_label_t), KM_SLEEP);
 568
 569         *config = NULL;
 570         for (l = 0; l < VDEV_LABELS; l++) {
 571                 uint64_t offset, state, txg = 0;
 572
 573                 /* read vdev label */
 574                 offset = vdev_label_offset(size, l, 0);
 575                 if (vdev_disk_physio(vd_lh, (caddr_t)label,
 576                     VDEV_SKIP_SIZE + VDEV_PHYS_SIZE, offset, B_READ) != 0)
 577                         continue;
 578
 579                 if (nvlist_unpack(label->vl_vdev_phys.vp_nvlist,
 580                     sizeof (label->vl_vdev_phys.vp_nvlist), config, 0) != 0) {
 581                         *config = NULL;
 582                         continue;
 583                 }
 584
 585                 if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_STATE,
 586                     &state) != 0 || state >= POOL_STATE_DESTROYED) {
 587                         nvlist_free(*config);
 588                         *config = NULL;
 589                         continue;
 590                 }
 591
 592                 if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_TXG,
 593                     &txg) != 0 || txg == 0) {
 594                         nvlist_free(*config);
 595                         *config = NULL;
 596                         continue;
 597                 }
 598
 599                 break;
 600         }
 601
 602         kmem_free(label, sizeof (vdev_label_t));
 603         (void) ldi_close(vd_lh, FREAD, kcred);
 604         if (*config == NULL)
 605                 error = EIDRM;
 606
 607         return (error);
 608 }