module/zfs/spa_config.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 /*
  23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
  25  * Copyright (c) 2013 by Delphix. All rights reserved.
  26  */
  27
  28 #include <sys/spa.h>
  29 #include <sys/spa_impl.h>
  30 #include <sys/nvpair.h>
  31 #include <sys/uio.h>
  32 #include <sys/fs/zfs.h>
  33 #include <sys/vdev_impl.h>
  34 #include <sys/zfs_ioctl.h>
  35 #include <sys/systeminfo.h>
  36 #include <sys/sunddi.h>
  37 #include <sys/zfeature.h>
  38 #ifdef _KERNEL
  39 #include <sys/kobj.h>
  40 #include <sys/zone.h>
  41 #endif
  42
  43 /*
  44  * Pool configuration repository.
  45  *
  46  * Pool configuration is stored as a packed nvlist on the filesystem.  By
  47  * default, all pools are stored in /etc/zfs/zpool.cache and loaded on boot
  48  * (when the ZFS module is loaded).  Pools can also have the 'cachefile'
  49  * property set that allows them to be stored in an alternate location until
  50  * the control of external software.
  51  *
  52  * For each cache file, we have a single nvlist which holds all the
  53  * configuration information.  When the module loads, we read this information
  54  * from /etc/zfs/zpool.cache and populate the SPA namespace.  This namespace is
  55  * maintained independently in spa.c.  Whenever the namespace is modified, or
  56  * the configuration of a pool is changed, we call spa_config_sync(), which
  57  * walks through all the active pools and writes the configuration to disk.
  58  */
  59
  60 static uint64_t spa_config_generation = 1;
  61
  62 /*
  63  * This can be overridden in userland to preserve an alternate namespace for
  64  * userland pools when doing testing.
  65  */
  66 char *spa_config_path = ZPOOL_CACHE;
  67 int zfs_autoimport_disable = 1;
  68
  69 /*
  70  * Called when the module is first loaded, this routine loads the configuration
  71  * file into the SPA namespace.  It does not actually open or load the pools; it
  72  * only populates the namespace.
  73  */
  74 void
  75 spa_config_load(void)
  76 {
  77         void *buf = NULL;
  78         nvlist_t *nvlist, *child;
  79         nvpair_t *nvpair;
  80         char *pathname;
  81         struct _buf *file;
  82         uint64_t fsize;
  83
  84 #ifdef _KERNEL
  85         if (zfs_autoimport_disable)
  86                 return;
  87 #endif
  88
  89         /*
  90          * Open the configuration file.
  91          */
  92         pathname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
  93
  94         (void) snprintf(pathname, MAXPATHLEN, "%s%s",
  95             (rootdir != NULL) ? "./" : "", spa_config_path);
  96
  97         file = kobj_open_file(pathname);
  98
  99         kmem_free(pathname, MAXPATHLEN);
 100
 101         if (file == (struct _buf *)-1)
 102                 return;
 103
 104         if (kobj_get_filesize(file, &fsize) != 0)
 105                 goto out;
 106
 107         buf = kmem_alloc(fsize, KM_SLEEP);
 108
 109         /*
 110          * Read the nvlist from the file.
 111          */
 112         if (kobj_read_file(file, buf, fsize, 0) < 0)
 113                 goto out;
 114
 115         /*
 116          * Unpack the nvlist.
 117          */
 118         if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0)
 119                 goto out;
 120
 121         /*
 122          * Iterate over all elements in the nvlist, creating a new spa_t for
 123          * each one with the specified configuration.
 124          */
 125         mutex_enter(&spa_namespace_lock);
 126         nvpair = NULL;
 127         while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) {
 128                 if (nvpair_type(nvpair) != DATA_TYPE_NVLIST)
 129                         continue;
 130
 131                 VERIFY(nvpair_value_nvlist(nvpair, &child) == 0);
 132
 133                 if (spa_lookup(nvpair_name(nvpair)) != NULL)
 134                         continue;
 135                 (void) spa_add(nvpair_name(nvpair), child, NULL);
 136         }
 137         mutex_exit(&spa_namespace_lock);
 138
 139         nvlist_free(nvlist);
 140
 141 out:
 142         if (buf != NULL)
 143                 kmem_free(buf, fsize);
 144
 145         kobj_close_file(file);
 146 }
 147
 148 static void
 149 spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
 150 {
 151         size_t buflen;
 152         char *buf;
 153         vnode_t *vp;
 154         int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX;
 155         int error;
 156         char *temp;
 157
 158         /*
 159          * If the nvlist is empty (NULL), then remove the old cachefile.
 160          */
 161         if (nvl == NULL) {
 162                 (void) vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE);
 163                 return;
 164         }
 165
 166         /*
 167          * Pack the configuration into a buffer.
 168          */
 169         VERIFY(nvlist_size(nvl, &buflen, NV_ENCODE_XDR) == 0);
 170
 171         buf = vmem_alloc(buflen, KM_SLEEP);
 172         temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
 173
 174         VERIFY(nvlist_pack(nvl, &buf, &buflen, NV_ENCODE_XDR,
 175             KM_SLEEP) == 0);
 176
 177 #if defined(__linux__) && defined(_KERNEL)
 178         /*
 179          * Write the configuration to disk.  Due to the complexity involved
 180          * in performing a rename from within the kernel the file is truncated
 181          * and overwritten in place.  In the event of an error the file is
 182          * unlinked to make sure we always have a consistent view of the data.
 183          */
 184         error = vn_open(dp->scd_path, UIO_SYSSPACE, oflags, 0644, &vp, 0, 0);
 185         if (error == 0) {
 186                 error = vn_rdwr(UIO_WRITE, vp, buf, buflen, 0,
 187                     UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred, NULL);
 188                 if (error == 0)
 189                         error = VOP_FSYNC(vp, FSYNC, kcred, NULL);
 190
 191                 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL);
 192
 193                 if (error)
 194                         (void) vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE);
 195         }
 196 #else
 197         /*
 198          * Write the configuration to disk.  We need to do the traditional
 199          * 'write to temporary file, sync, move over original' to make sure we
 200          * always have a consistent view of the data.
 201          */
 202         (void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path);
 203
 204         error = vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0);
 205         if (error == 0) {
 206                 if (vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE,
 207                     0, RLIM64_INFINITY, kcred, NULL) == 0 &&
 208                     VOP_FSYNC(vp, FSYNC, kcred, NULL) == 0) {
 209                         (void) vn_rename(temp, dp->scd_path, UIO_SYSSPACE);
 210                 }
 211                 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL);
 212         }
 213
 214         (void) vn_remove(temp, UIO_SYSSPACE, RMFILE);
 215 #endif
 216
 217         vmem_free(buf, buflen);
 218         kmem_free(temp, MAXPATHLEN);
 219 }
 220
 221 /*
 222  * Synchronize pool configuration to disk.  This must be called with the
 223  * namespace lock held. Synchronizing the pool cache is typically done after
 224  * the configuration has been synced to the MOS. This exposes a window where
 225  * the MOS config will have been updated but the cache file has not. If
 226  * the system were to crash at that instant then the cached config may not
 227  * contain the correct information to open the pool and an explicity import
 228  * would be required.
 229  */
 230 void
 231 spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent)
 232 {
 233         spa_config_dirent_t *dp, *tdp;
 234         nvlist_t *nvl;
 235         char *pool_name;
 236
 237         ASSERT(MUTEX_HELD(&spa_namespace_lock));
 238
 239         if (rootdir == NULL || !(spa_mode_global & FWRITE))
 240                 return;
 241
 242         /*
 243          * Iterate over all cachefiles for the pool, past or present.  When the
 244          * cachefile is changed, the new one is pushed onto this list, allowing
 245          * us to update previous cachefiles that no longer contain this pool.
 246          */
 247         for (dp = list_head(&target->spa_config_list); dp != NULL;
 248             dp = list_next(&target->spa_config_list, dp)) {
 249                 spa_t *spa = NULL;
 250                 if (dp->scd_path == NULL)
 251                         continue;
 252
 253                 /*
 254                  * Iterate over all pools, adding any matching pools to 'nvl'.
 255                  */
 256                 nvl = NULL;
 257                 while ((spa = spa_next(spa)) != NULL) {
 258                         /*
 259                          * Skip over our own pool if we're about to remove
 260                          * ourselves from the spa namespace or any pool that
 261                          * is readonly. Since we cannot guarantee that a
 262                          * readonly pool would successfully import upon reboot,
 263                          * we don't allow them to be written to the cache file.
 264                          */
 265                         if ((spa == target && removing) ||
 266                             !spa_writeable(spa))
 267                                 continue;
 268
 269                         mutex_enter(&spa->spa_props_lock);
 270                         tdp = list_head(&spa->spa_config_list);
 271                         if (spa->spa_config == NULL ||
 272                             tdp->scd_path == NULL ||
 273                             strcmp(tdp->scd_path, dp->scd_path) != 0) {
 274                                 mutex_exit(&spa->spa_props_lock);
 275                                 continue;
 276                         }
 277
 278                         if (nvl == NULL)
 279                                 VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME,
 280                                     KM_SLEEP) == 0);
 281
 282                         if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) {
 283                                 VERIFY0(nvlist_lookup_string(spa->spa_config,
 284                                         ZPOOL_CONFIG_POOL_NAME, &pool_name));
 285                         } else
 286                                 pool_name = spa_name(spa);
 287
 288                         VERIFY(nvlist_add_nvlist(nvl, pool_name,
 289                             spa->spa_config) == 0);
 290                         mutex_exit(&spa->spa_props_lock);
 291                 }
 292
 293                 spa_config_write(dp, nvl);
 294                 nvlist_free(nvl);
 295         }
 296
 297         /*
 298          * Remove any config entries older than the current one.
 299          */
 300         dp = list_head(&target->spa_config_list);
 301         while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) {
 302                 list_remove(&target->spa_config_list, tdp);
 303                 if (tdp->scd_path != NULL)
 304                         spa_strfree(tdp->scd_path);
 305                 kmem_free(tdp, sizeof (spa_config_dirent_t));
 306         }
 307
 308         spa_config_generation++;
 309
 310         if (postsysevent)
 311                 spa_event_notify(target, NULL, FM_EREPORT_ZFS_CONFIG_SYNC);
 312 }
 313
 314 /*
 315  * Sigh.  Inside a local zone, we don't have access to /etc/zfs/zpool.cache,
 316  * and we don't want to allow the local zone to see all the pools anyway.
 317  * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration
 318  * information for all pool visible within the zone.
 319  */
 320 nvlist_t *
 321 spa_all_configs(uint64_t *generation)
 322 {
 323         nvlist_t *pools;
 324         spa_t *spa = NULL;
 325
 326         if (*generation == spa_config_generation)
 327                 return (NULL);
 328
 329         VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 330
 331         mutex_enter(&spa_namespace_lock);
 332         while ((spa = spa_next(spa)) != NULL) {
 333                 if (INGLOBALZONE(curproc) ||
 334                     zone_dataset_visible(spa_name(spa), NULL)) {
 335                         mutex_enter(&spa->spa_props_lock);
 336                         VERIFY(nvlist_add_nvlist(pools, spa_name(spa),
 337                             spa->spa_config) == 0);
 338                         mutex_exit(&spa->spa_props_lock);
 339                 }
 340         }
 341         *generation = spa_config_generation;
 342         mutex_exit(&spa_namespace_lock);
 343
 344         return (pools);
 345 }
 346
 347 void
 348 spa_config_set(spa_t *spa, nvlist_t *config)
 349 {
 350         mutex_enter(&spa->spa_props_lock);
 351         if (spa->spa_config != NULL)
 352                 nvlist_free(spa->spa_config);
 353         spa->spa_config = config;
 354         mutex_exit(&spa->spa_props_lock);
 355 }
 356
 357 /*
 358  * Generate the pool's configuration based on the current in-core state.
 359  *
 360  * We infer whether to generate a complete config or just one top-level config
 361  * based on whether vd is the root vdev.
 362  */
 363 nvlist_t *
 364 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
 365 {
 366         nvlist_t *config, *nvroot;
 367         vdev_t *rvd = spa->spa_root_vdev;
 368         unsigned long hostid = 0;
 369         boolean_t locked = B_FALSE;
 370         uint64_t split_guid;
 371         char *pool_name;
 372
 373         if (vd == NULL) {
 374                 vd = rvd;
 375                 locked = B_TRUE;
 376                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
 377         }
 378
 379         ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) ==
 380             (SCL_CONFIG | SCL_STATE));
 381
 382         /*
 383          * If txg is -1, report the current value of spa->spa_config_txg.
 384          */
 385         if (txg == -1ULL)
 386                 txg = spa->spa_config_txg;
 387
 388         /*
 389          * Originally, users had to handle spa namespace collisions by either
 390          * exporting the already imported pool or by specifying a new name for
 391          * the pool with a conflicting name. In the case of root pools from
 392          * virtual guests, neither approach to collision resolution is
 393          * reasonable. This is addressed by extending the new name syntax with
 394          * an option to specify that the new name is temporary. When specified,
 395          * ZFS_IMPORT_TEMP_NAME will be set in spa->spa_import_flags to tell us
 396          * to use the previous name, which we do below.
 397          */
 398         if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) {
 399                 VERIFY0(nvlist_lookup_string(spa->spa_config,
 400                         ZPOOL_CONFIG_POOL_NAME, &pool_name));
 401         } else
 402                 pool_name = spa_name(spa);
 403
 404         VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 405
 406         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
 407             spa_version(spa)) == 0);
 408         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
 409             pool_name) == 0);
 410         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
 411             spa_state(spa)) == 0);
 412         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
 413             txg) == 0);
 414         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
 415             spa_guid(spa)) == 0);
 416         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_ERRATA,
 417             spa->spa_errata) == 0);
 418         VERIFY(spa->spa_comment == NULL || nvlist_add_string(config,
 419             ZPOOL_CONFIG_COMMENT, spa->spa_comment) == 0);
 420
 421
 422 #ifdef  _KERNEL
 423         hostid = zone_get_hostid(NULL);
 424 #else   /* _KERNEL */
 425         /*
 426          * We're emulating the system's hostid in userland, so we can't use
 427          * zone_get_hostid().
 428          */
 429         (void) ddi_strtoul(hw_serial, NULL, 10, &hostid);
 430 #endif  /* _KERNEL */
 431         if (hostid != 0) {
 432                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID,
 433                     hostid) == 0);
 434         }
 435         VERIFY0(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME,
 436             utsname()->nodename));
 437
 438         if (vd != rvd) {
 439                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID,
 440                     vd->vdev_top->vdev_guid) == 0);
 441                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_GUID,
 442                     vd->vdev_guid) == 0);
 443                 if (vd->vdev_isspare)
 444                         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_SPARE,
 445                             1ULL) == 0);
 446                 if (vd->vdev_islog)
 447                         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_LOG,
 448                             1ULL) == 0);
 449                 vd = vd->vdev_top;              /* label contains top config */
 450         } else {
 451                 /*
 452                  * Only add the (potentially large) split information
 453                  * in the mos config, and not in the vdev labels
 454                  */
 455                 if (spa->spa_config_splitting != NULL)
 456                         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT,
 457                             spa->spa_config_splitting) == 0);
 458         }
 459
 460         /*
 461          * Add the top-level config.  We even add this on pools which
 462          * don't support holes in the namespace.
 463          */
 464         vdev_top_config_generate(spa, config);
 465
 466         /*
 467          * If we're splitting, record the original pool's guid.
 468          */
 469         if (spa->spa_config_splitting != NULL &&
 470             nvlist_lookup_uint64(spa->spa_config_splitting,
 471             ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) {
 472                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID,
 473                     split_guid) == 0);
 474         }
 475
 476         nvroot = vdev_config_generate(spa, vd, getstats, 0);
 477         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
 478         nvlist_free(nvroot);
 479
 480         /*
 481          * Store what's necessary for reading the MOS in the label.
 482          */
 483         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ,
 484             spa->spa_label_features) == 0);
 485
 486         if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) {
 487                 ddt_histogram_t *ddh;
 488                 ddt_stat_t *dds;
 489                 ddt_object_t *ddo;
 490
 491                 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP);
 492                 ddt_get_dedup_histogram(spa, ddh);
 493                 VERIFY(nvlist_add_uint64_array(config,
 494                     ZPOOL_CONFIG_DDT_HISTOGRAM,
 495                     (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t)) == 0);
 496                 kmem_free(ddh, sizeof (ddt_histogram_t));
 497
 498                 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP);
 499                 ddt_get_dedup_object_stats(spa, ddo);
 500                 VERIFY(nvlist_add_uint64_array(config,
 501                     ZPOOL_CONFIG_DDT_OBJ_STATS,
 502                     (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t)) == 0);
 503                 kmem_free(ddo, sizeof (ddt_object_t));
 504
 505                 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP);
 506                 ddt_get_dedup_stats(spa, dds);
 507                 VERIFY(nvlist_add_uint64_array(config,
 508                     ZPOOL_CONFIG_DDT_STATS,
 509                     (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t)) == 0);
 510                 kmem_free(dds, sizeof (ddt_stat_t));
 511         }
 512
 513         if (locked)
 514                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
 515
 516         return (config);
 517 }
 518
 519 /*
 520  * Update all disk labels, generate a fresh config based on the current
 521  * in-core state, and sync the global config cache (do not sync the config
 522  * cache if this is a booting rootpool).
 523  */
 524 void
 525 spa_config_update(spa_t *spa, int what)
 526 {
 527         vdev_t *rvd = spa->spa_root_vdev;
 528         uint64_t txg;
 529         int c;
 530
 531         ASSERT(MUTEX_HELD(&spa_namespace_lock));
 532
 533         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
 534         txg = spa_last_synced_txg(spa) + 1;
 535         if (what == SPA_CONFIG_UPDATE_POOL) {
 536                 vdev_config_dirty(rvd);
 537         } else {
 538                 /*
 539                  * If we have top-level vdevs that were added but have
 540                  * not yet been prepared for allocation, do that now.
 541                  * (It's safe now because the config cache is up to date,
 542                  * so it will be able to translate the new DVAs.)
 543                  * See comments in spa_vdev_add() for full details.
 544                  */
 545                 for (c = 0; c < rvd->vdev_children; c++) {
 546                         vdev_t *tvd = rvd->vdev_child[c];
 547                         if (tvd->vdev_ms_array == 0)
 548                                 vdev_metaslab_set_size(tvd);
 549                         vdev_expand(tvd, txg);
 550                 }
 551         }
 552         spa_config_exit(spa, SCL_ALL, FTAG);
 553
 554         /*
 555          * Wait for the mosconfig to be regenerated and synced.
 556          */
 557         txg_wait_synced(spa->spa_dsl_pool, txg);
 558
 559         /*
 560          * Update the global config cache to reflect the new mosconfig.
 561          */
 562         if (!spa->spa_is_root)
 563                 spa_config_sync(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL);
 564
 565         if (what == SPA_CONFIG_UPDATE_POOL)
 566                 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS);
 567 }
 568
 569 #if defined(_KERNEL) && defined(HAVE_SPL)
 570 EXPORT_SYMBOL(spa_config_sync);
 571 EXPORT_SYMBOL(spa_config_load);
 572 EXPORT_SYMBOL(spa_all_configs);
 573 EXPORT_SYMBOL(spa_config_set);
 574 EXPORT_SYMBOL(spa_config_generate);
 575 EXPORT_SYMBOL(spa_config_update);
 576
 577 module_param(spa_config_path, charp, 0444);
 578 MODULE_PARM_DESC(spa_config_path, "SPA config file (/etc/zfs/zpool.cache)");
 579
 580 module_param(zfs_autoimport_disable, int, 0644);
 581 MODULE_PARM_DESC(zfs_autoimport_disable, "Disable pool import at module load");
 582
 583 #endif