zfs/lib/libzpool/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 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #pragma ident   "@(#)vdev_disk.c        1.15    08/04/09 SMI"
  27
  28 #include <sys/zfs_context.h>
  29 #include <sys/spa.h>
  30 #include <sys/refcount.h>
  31 #include <sys/vdev_disk.h>
  32 #include <sys/vdev_impl.h>
  33 #include <sys/fs/zfs.h>
  34 #include <sys/zio.h>
  35 #include <sys/sunldi.h>
  36
  37 /*
  38  * Virtual device vector for disks.
  39  */
  40
  41 extern ldi_ident_t zfs_li;
  42
  43 typedef struct vdev_disk_buf {
  44         buf_t   vdb_buf;
  45         zio_t   *vdb_io;
  46 } vdev_disk_buf_t;
  47
  48 static int
  49 vdev_disk_open_common(vdev_t *vd)
  50 {
  51         vdev_disk_t *dvd;
  52         dev_t dev;
  53         int error;
  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                 vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
  60                 return (EINVAL);
  61         }
  62
  63         dvd = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_disk_t), KM_SLEEP);
  64
  65         /*
  66          * When opening a disk device, we want to preserve the user's original
  67          * intent.  We always want to open the device by the path the user gave
  68          * us, even if it is one of multiple paths to the save device.  But we
  69          * also want to be able to survive disks being removed/recabled.
  70          * Therefore the sequence of opening devices is:
  71          *
  72          * 1. Try opening the device by path.  For legacy pools without the
  73          *    'whole_disk' property, attempt to fix the path by appending 's0'.
  74          *
  75          * 2. If the devid of the device matches the stored value, return
  76          *    success.
  77          *
  78          * 3. Otherwise, the device may have moved.  Try opening the device
  79          *    by the devid instead.
  80          *
  81          */
  82         if (vd->vdev_devid != NULL) {
  83                 if (ddi_devid_str_decode(vd->vdev_devid, &dvd->vd_devid,
  84                     &dvd->vd_minor) != 0) {
  85                         vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
  86                         return (EINVAL);
  87                 }
  88         }
  89
  90         error = EINVAL;         /* presume failure */
  91
  92         if (vd->vdev_path != NULL) {
  93                 ddi_devid_t devid;
  94
  95                 if (vd->vdev_wholedisk == -1ULL) {
  96                         size_t len = strlen(vd->vdev_path) + 3;
  97                         char *buf = kmem_alloc(len, KM_SLEEP);
  98                         ldi_handle_t lh;
  99
 100                         (void) snprintf(buf, len, "%ss0", vd->vdev_path);
 101
 102                         if (ldi_open_by_name(buf, spa_mode, kcred,
 103                             &lh, zfs_li) == 0) {
 104                                 spa_strfree(vd->vdev_path);
 105                                 vd->vdev_path = buf;
 106                                 vd->vdev_wholedisk = 1ULL;
 107                                 (void) ldi_close(lh, spa_mode, kcred);
 108                         } else {
 109                                 kmem_free(buf, len);
 110                         }
 111                 }
 112
 113                 error = ldi_open_by_name(vd->vdev_path, spa_mode, kcred,
 114                     &dvd->vd_lh, zfs_li);
 115
 116                 /*
 117                  * Compare the devid to the stored value.
 118                  */
 119                 if (error == 0 && vd->vdev_devid != NULL &&
 120                     ldi_get_devid(dvd->vd_lh, &devid) == 0) {
 121                         if (ddi_devid_compare(devid, dvd->vd_devid) != 0) {
 122                                 error = EINVAL;
 123                                 (void) ldi_close(dvd->vd_lh, spa_mode, kcred);
 124                                 dvd->vd_lh = NULL;
 125                         }
 126                         ddi_devid_free(devid);
 127                 }
 128
 129                 /*
 130                  * If we succeeded in opening the device, but 'vdev_wholedisk'
 131                  * is not yet set, then this must be a slice.
 132                  */
 133                 if (error == 0 && vd->vdev_wholedisk == -1ULL)
 134                         vd->vdev_wholedisk = 0;
 135         }
 136
 137         /*
 138          * If we were unable to open by path, or the devid check fails, open by
 139          * devid instead.
 140          */
 141         if (error != 0 && vd->vdev_devid != NULL)
 142                 error = ldi_open_by_devid(dvd->vd_devid, dvd->vd_minor,
 143                     spa_mode, kcred, &dvd->vd_lh, zfs_li);
 144
 145         /*
 146          * If all else fails, then try opening by physical path (if available)
 147          * or the logical path (if we failed due to the devid check).  While not
 148          * as reliable as the devid, this will give us something, and the higher
 149          * level vdev validation will prevent us from opening the wrong device.
 150          */
 151         if (error) {
 152                 if (vd->vdev_physpath != NULL &&
 153                     (dev = ddi_pathname_to_dev_t(vd->vdev_physpath)) != ENODEV)
 154                         error = ldi_open_by_dev(&dev, OTYP_BLK, spa_mode,
 155                             kcred, &dvd->vd_lh, zfs_li);
 156
 157                 /*
 158                  * Note that we don't support the legacy auto-wholedisk support
 159                  * as above.  This hasn't been used in a very long time and we
 160                  * don't need to propagate its oddities to this edge condition.
 161                  */
 162                 if (error && vd->vdev_path != NULL)
 163                         error = ldi_open_by_name(vd->vdev_path, spa_mode, kcred,
 164                             &dvd->vd_lh, zfs_li);
 165         }
 166
 167         if (error)
 168                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
 169
 170         return (error);
 171 }
 172
 173 static int
 174 vdev_disk_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
 175 {
 176         vdev_disk_t *dvd;
 177         struct dk_minfo dkm;
 178         int error;
 179         dev_t dev;
 180         int otyp;
 181
 182         error = vdev_disk_open_common(vd);
 183         if (error)
 184                 return (error);
 185
 186         dvd = vd->vdev_tsd;
 187         /*
 188          * Once a device is opened, verify that the physical device path (if
 189          * available) is up to date.
 190          */
 191         if (ldi_get_dev(dvd->vd_lh, &dev) == 0 &&
 192             ldi_get_otyp(dvd->vd_lh, &otyp) == 0) {
 193                 char *physpath, *minorname;
 194
 195                 physpath = kmem_alloc(MAXPATHLEN, KM_SLEEP);
 196                 minorname = NULL;
 197                 if (ddi_dev_pathname(dev, otyp, physpath) == 0 &&
 198                     ldi_get_minor_name(dvd->vd_lh, &minorname) == 0 &&
 199                     (vd->vdev_physpath == NULL ||
 200                     strcmp(vd->vdev_physpath, physpath) != 0)) {
 201                         if (vd->vdev_physpath)
 202                                 spa_strfree(vd->vdev_physpath);
 203                         (void) strlcat(physpath, ":", MAXPATHLEN);
 204                         (void) strlcat(physpath, minorname, MAXPATHLEN);
 205                         vd->vdev_physpath = spa_strdup(physpath);
 206                 }
 207                 if (minorname)
 208                         kmem_free(minorname, strlen(minorname) + 1);
 209                 kmem_free(physpath, MAXPATHLEN);
 210         }
 211
 212         /*
 213          * Determine the actual size of the device.
 214          */
 215         if (ldi_get_size(dvd->vd_lh, psize) != 0) {
 216                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
 217                 return (EINVAL);
 218         }
 219
 220         /*
 221          * If we own the whole disk, try to enable disk write caching.
 222          * We ignore errors because it's OK if we can't do it.
 223          */
 224         if (vd->vdev_wholedisk == 1) {
 225                 int wce = 1;
 226                 (void) ldi_ioctl(dvd->vd_lh, DKIOCSETWCE, (intptr_t)&wce,
 227                     FKIOCTL, kcred, NULL);
 228         }
 229
 230         /*
 231          * Determine the device's minimum transfer size.
 232          * If the ioctl isn't supported, assume DEV_BSIZE.
 233          */
 234         if (ldi_ioctl(dvd->vd_lh, DKIOCGMEDIAINFO, (intptr_t)&dkm,
 235             FKIOCTL, kcred, NULL) != 0)
 236                 dkm.dki_lbsize = DEV_BSIZE;
 237
 238         *ashift = highbit(MAX(dkm.dki_lbsize, SPA_MINBLOCKSIZE)) - 1;
 239
 240         /*
 241          * Clear the nowritecache bit, so that on a vdev_reopen() we will
 242          * try again.
 243          */
 244         vd->vdev_nowritecache = B_FALSE;
 245
 246         return (0);
 247 }
 248
 249 static void
 250 vdev_disk_close(vdev_t *vd)
 251 {
 252         vdev_disk_t *dvd = vd->vdev_tsd;
 253
 254         if (dvd == NULL)
 255                 return;
 256
 257         if (dvd->vd_minor != NULL)
 258                 ddi_devid_str_free(dvd->vd_minor);
 259
 260         if (dvd->vd_devid != NULL)
 261                 ddi_devid_free(dvd->vd_devid);
 262
 263         if (dvd->vd_lh != NULL)
 264                 (void) ldi_close(dvd->vd_lh, spa_mode, kcred);
 265
 266         kmem_free(dvd, sizeof (vdev_disk_t));
 267         vd->vdev_tsd = NULL;
 268 }
 269
 270 int
 271 vdev_disk_physio(ldi_handle_t vd_lh, caddr_t data, size_t size,
 272     uint64_t offset, int flags)
 273 {
 274         buf_t *bp;
 275         int error = 0;
 276
 277         if (vd_lh == NULL)
 278                 return (EINVAL);
 279
 280         ASSERT(flags & B_READ || flags & B_WRITE);
 281
 282         bp = getrbuf(KM_SLEEP);
 283         bp->b_flags = flags | B_BUSY | B_NOCACHE | B_FAILFAST;
 284         bp->b_bcount = size;
 285         bp->b_un.b_addr = (void *)data;
 286         bp->b_lblkno = lbtodb(offset);
 287         bp->b_bufsize = size;
 288
 289         error = ldi_strategy(vd_lh, bp);
 290         ASSERT(error == 0);
 291         if ((error = biowait(bp)) == 0 && bp->b_resid != 0)
 292                 error = EIO;
 293         freerbuf(bp);
 294
 295         return (error);
 296 }
 297
 298 static int
 299 vdev_disk_probe_io(vdev_t *vd, caddr_t data, size_t size, uint64_t offset,
 300     int flags)
 301 {
 302         int error = 0;
 303         vdev_disk_t *dvd = vd->vdev_tsd;
 304
 305         if (vd == NULL || dvd == NULL || dvd->vd_lh == NULL)
 306                 return (EINVAL);
 307
 308         error = vdev_disk_physio(dvd->vd_lh, data, size, offset, flags);
 309
 310         if (zio_injection_enabled && error == 0)
 311                 error = zio_handle_device_injection(vd, EIO);
 312
 313         return (error);
 314 }
 315
 316 /*
 317  * Determine if the underlying device is accessible by reading and writing
 318  * to a known location. We must be able to do this during syncing context
 319  * and thus we cannot set the vdev state directly.
 320  */
 321 static int
 322 vdev_disk_probe(vdev_t *vd)
 323 {
 324         uint64_t offset;
 325         vdev_t *nvd;
 326         int l, error = 0, retries = 0;
 327         char *vl_pad;
 328
 329         if (vd == NULL)
 330                 return (EINVAL);
 331
 332         /* Hijack the current vdev */
 333         nvd = vd;
 334
 335         /*
 336          * Pick a random label to rewrite.
 337          */
 338         l = spa_get_random(VDEV_LABELS);
 339         ASSERT(l < VDEV_LABELS);
 340
 341         offset = vdev_label_offset(vd->vdev_psize, l,
 342             offsetof(vdev_label_t, vl_pad));
 343
 344         vl_pad = kmem_alloc(VDEV_SKIP_SIZE, KM_SLEEP);
 345
 346         /*
 347          * Try to read and write to a special location on the
 348          * label. We use the existing vdev initially and only
 349          * try to create and reopen it if we encounter a failure.
 350          */
 351         while ((error = vdev_disk_probe_io(nvd, vl_pad, VDEV_SKIP_SIZE,
 352             offset, B_READ)) != 0 && retries == 0) {
 353
 354                 nvd = kmem_zalloc(sizeof (vdev_t), KM_SLEEP);
 355                 if (vd->vdev_path)
 356                         nvd->vdev_path = spa_strdup(vd->vdev_path);
 357                 if (vd->vdev_physpath)
 358                         nvd->vdev_physpath = spa_strdup(vd->vdev_physpath);
 359                 if (vd->vdev_devid)
 360                         nvd->vdev_devid = spa_strdup(vd->vdev_devid);
 361                 nvd->vdev_wholedisk = vd->vdev_wholedisk;
 362                 nvd->vdev_guid = vd->vdev_guid;
 363                 retries++;
 364
 365                 error = vdev_disk_open_common(nvd);
 366                 if (error)
 367                         break;
 368         }
 369
 370         if (!error) {
 371                 error = vdev_disk_probe_io(nvd, vl_pad, VDEV_SKIP_SIZE,
 372                     offset, B_WRITE);
 373         }
 374
 375         /* Clean up if we allocated a new vdev */
 376         if (retries) {
 377                 vdev_disk_close(nvd);
 378                 if (nvd->vdev_path)
 379                         spa_strfree(nvd->vdev_path);
 380                 if (nvd->vdev_physpath)
 381                         spa_strfree(nvd->vdev_physpath);
 382                 if (nvd->vdev_devid)
 383                         spa_strfree(nvd->vdev_devid);
 384                 kmem_free(nvd, sizeof (vdev_t));
 385         }
 386         kmem_free(vl_pad, VDEV_SKIP_SIZE);
 387
 388         /* Reset the failing flag */
 389         if (!error)
 390                 vd->vdev_is_failing = B_FALSE;
 391
 392         return (error);
 393 }
 394
 395 static void
 396 vdev_disk_io_intr(buf_t *bp)
 397 {
 398         vdev_disk_buf_t *vdb = (vdev_disk_buf_t *)bp;
 399         zio_t *zio = vdb->vdb_io;
 400
 401         if ((zio->io_error = geterror(bp)) == 0 && bp->b_resid != 0)
 402                 zio->io_error = EIO;
 403
 404         kmem_free(vdb, sizeof (vdev_disk_buf_t));
 405
 406         zio_interrupt(zio);
 407 }
 408
 409 static void
 410 vdev_disk_ioctl_done(void *zio_arg, int error)
 411 {
 412         zio_t *zio = zio_arg;
 413
 414         zio->io_error = error;
 415
 416         zio_interrupt(zio);
 417 }
 418
 419 static int
 420 vdev_disk_io_start(zio_t *zio)
 421 {
 422         vdev_t *vd = zio->io_vd;
 423         vdev_disk_t *dvd = vd->vdev_tsd;
 424         vdev_disk_buf_t *vdb;
 425         buf_t *bp;
 426         int flags, error;
 427
 428         if (zio->io_type == ZIO_TYPE_IOCTL) {
 429                 zio_vdev_io_bypass(zio);
 430
 431                 /* XXPOLICY */
 432                 if (!vdev_readable(vd)) {
 433                         zio->io_error = ENXIO;
 434                         return (ZIO_PIPELINE_CONTINUE);
 435                 }
 436
 437                 switch (zio->io_cmd) {
 438
 439                 case DKIOCFLUSHWRITECACHE:
 440
 441                         if (zfs_nocacheflush)
 442                                 break;
 443
 444                         if (vd->vdev_nowritecache) {
 445                                 zio->io_error = ENOTSUP;
 446                                 break;
 447                         }
 448
 449                         zio->io_dk_callback.dkc_callback = vdev_disk_ioctl_done;
 450                         zio->io_dk_callback.dkc_flag = FLUSH_VOLATILE;
 451                         zio->io_dk_callback.dkc_cookie = zio;
 452
 453                         error = ldi_ioctl(dvd->vd_lh, zio->io_cmd,
 454                             (uintptr_t)&zio->io_dk_callback,
 455                             FKIOCTL, kcred, NULL);
 456
 457                         if (error == 0) {
 458                                 /*
 459                                  * The ioctl will be done asychronously,
 460                                  * and will call vdev_disk_ioctl_done()
 461                                  * upon completion.
 462                                  */
 463                                 return (ZIO_PIPELINE_STOP);
 464                         }
 465
 466                         if (error == ENOTSUP || error == ENOTTY) {
 467                                 /*
 468                                  * If we get ENOTSUP or ENOTTY, we know that
 469                                  * no future attempts will ever succeed.
 470                                  * In this case we set a persistent bit so
 471                                  * that we don't bother with the ioctl in the
 472                                  * future.
 473                                  */
 474                                 vd->vdev_nowritecache = B_TRUE;
 475                         }
 476                         zio->io_error = error;
 477
 478                         break;
 479
 480                 default:
 481                         zio->io_error = ENOTSUP;
 482                 }
 483
 484                 return (ZIO_PIPELINE_CONTINUE);
 485         }
 486
 487         if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio) == 0)
 488                 return (ZIO_PIPELINE_STOP);
 489
 490         if ((zio = vdev_queue_io(zio)) == NULL)
 491                 return (ZIO_PIPELINE_STOP);
 492
 493         if (zio->io_type == ZIO_TYPE_WRITE)
 494                 error = vdev_writeable(vd) ? vdev_error_inject(vd, zio) : ENXIO;
 495         else
 496                 error = vdev_readable(vd) ? vdev_error_inject(vd, zio) : ENXIO;
 497         error = (vd->vdev_remove_wanted || vd->vdev_is_failing) ? ENXIO : error;
 498
 499         if (error) {
 500                 zio->io_error = error;
 501                 zio_interrupt(zio);
 502                 return (ZIO_PIPELINE_STOP);
 503         }
 504
 505         flags = (zio->io_type == ZIO_TYPE_READ ? B_READ : B_WRITE);
 506         flags |= B_BUSY | B_NOCACHE;
 507         if (zio->io_flags & ZIO_FLAG_FAILFAST)
 508                 flags |= B_FAILFAST;
 509
 510         vdb = kmem_alloc(sizeof (vdev_disk_buf_t), KM_SLEEP);
 511
 512         vdb->vdb_io = zio;
 513         bp = &vdb->vdb_buf;
 514
 515         bioinit(bp);
 516         bp->b_flags = flags;
 517         bp->b_bcount = zio->io_size;
 518         bp->b_un.b_addr = zio->io_data;
 519         bp->b_lblkno = lbtodb(zio->io_offset);
 520         bp->b_bufsize = zio->io_size;
 521         bp->b_iodone = (int (*)())vdev_disk_io_intr;
 522
 523         error = ldi_strategy(dvd->vd_lh, bp);
 524         /* ldi_strategy() will return non-zero only on programming errors */
 525         ASSERT(error == 0);
 526
 527         return (ZIO_PIPELINE_STOP);
 528 }
 529
 530 static int
 531 vdev_disk_io_done(zio_t *zio)
 532 {
 533         vdev_queue_io_done(zio);
 534
 535         if (zio->io_type == ZIO_TYPE_WRITE)
 536                 vdev_cache_write(zio);
 537
 538         if (zio_injection_enabled && zio->io_error == 0)
 539                 zio->io_error = zio_handle_device_injection(zio->io_vd, EIO);
 540
 541         /*
 542          * If the device returned EIO, then attempt a DKIOCSTATE ioctl to see if
 543          * the device has been removed.  If this is the case, then we trigger an
 544          * asynchronous removal of the device. Otherwise, probe the device and
 545          * make sure it's still accessible.
 546          */
 547         if (zio->io_error == EIO) {
 548                 vdev_t *vd = zio->io_vd;
 549                 vdev_disk_t *dvd = vd->vdev_tsd;
 550                 int state;
 551
 552                 state = DKIO_NONE;
 553                 if (dvd && ldi_ioctl(dvd->vd_lh, DKIOCSTATE, (intptr_t)&state,
 554                     FKIOCTL, kcred, NULL) == 0 &&
 555                     state != DKIO_INSERTED) {
 556                         vd->vdev_remove_wanted = B_TRUE;
 557                         spa_async_request(zio->io_spa, SPA_ASYNC_REMOVE);
 558                 } else if (vdev_probe(vd) != 0) {
 559                         ASSERT(vd->vdev_ops->vdev_op_leaf);
 560                         vd->vdev_is_failing = B_TRUE;
 561                 }
 562         }
 563
 564         return (ZIO_PIPELINE_CONTINUE);
 565 }
 566
 567 vdev_ops_t vdev_disk_ops = {
 568         vdev_disk_open,
 569         vdev_disk_close,
 570         vdev_disk_probe,
 571         vdev_default_asize,
 572         vdev_disk_io_start,
 573         vdev_disk_io_done,
 574         NULL,
 575         VDEV_TYPE_DISK,         /* name of this vdev type */
 576         B_TRUE                  /* leaf vdev */
 577 };
 578
 579 /*
 580  * Given the root disk device pathname, read the label from the device,
 581  * and construct a configuration nvlist.
 582  */
 583 nvlist_t *
 584 vdev_disk_read_rootlabel(char *devpath)
 585 {
 586         nvlist_t *config = NULL;
 587         ldi_handle_t vd_lh;
 588         vdev_label_t *label;
 589         uint64_t s, size;
 590         int l;
 591
 592         /*
 593          * Read the device label and build the nvlist.
 594          */
 595         if (ldi_open_by_name(devpath, FREAD, kcred, &vd_lh, zfs_li))
 596                 return (NULL);
 597
 598         if (ldi_get_size(vd_lh, &s))
 599                 return (NULL);
 600
 601         size = P2ALIGN_TYPED(s, sizeof (vdev_label_t), uint64_t);
 602         label = kmem_alloc(sizeof (vdev_label_t), KM_SLEEP);
 603
 604         for (l = 0; l < VDEV_LABELS; l++) {
 605                 uint64_t offset, state, txg = 0;
 606
 607                 /* read vdev label */
 608                 offset = vdev_label_offset(size, l, 0);
 609                 if (vdev_disk_physio(vd_lh, (caddr_t)label,
 610                     VDEV_SKIP_SIZE + VDEV_BOOT_HEADER_SIZE +
 611                     VDEV_PHYS_SIZE, offset, B_READ) != 0)
 612                         continue;
 613
 614                 if (nvlist_unpack(label->vl_vdev_phys.vp_nvlist,
 615                     sizeof (label->vl_vdev_phys.vp_nvlist), &config, 0) != 0) {
 616                         config = NULL;
 617                         continue;
 618                 }
 619
 620                 if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_STATE,
 621                     &state) != 0 || state >= POOL_STATE_DESTROYED) {
 622                         nvlist_free(config);
 623                         config = NULL;
 624                         continue;
 625                 }
 626
 627                 if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
 628                     &txg) != 0 || txg == 0) {
 629                         nvlist_free(config);
 630                         config = NULL;
 631                         continue;
 632                 }
 633
 634                 break;
 635         }
 636
 637         kmem_free(label, sizeof (vdev_label_t));
 638         return (config);
 639 }