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 (c) 2011, 2014 by Delphix. All rights reserved.
  25  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
  26  */
  27 
  28 /*
  29  * SPA: Storage Pool Allocator
  30  *
  31  * This file contains all the routines used when modifying on-disk SPA state.
  32  * This includes opening, importing, destroying, exporting a pool, and syncing a
  33  * pool.
  34  */
  35 
  36 #include <sys/zfs_context.h>
  37 #include <sys/fm/fs/zfs.h>
  38 #include <sys/spa_impl.h>
  39 #include <sys/zio.h>
  40 #include <sys/zio_checksum.h>
  41 #include <sys/dmu.h>
  42 #include <sys/dmu_tx.h>
  43 #include <sys/zap.h>
  44 #include <sys/zil.h>
  45 #include <sys/ddt.h>
  46 #include <sys/vdev_impl.h>
  47 #include <sys/metaslab.h>
  48 #include <sys/metaslab_impl.h>
  49 #include <sys/uberblock_impl.h>
  50 #include <sys/txg.h>
  51 #include <sys/avl.h>
  52 #include <sys/dmu_traverse.h>
  53 #include <sys/dmu_objset.h>
  54 #include <sys/unique.h>
  55 #include <sys/dsl_pool.h>
  56 #include <sys/dsl_dataset.h>
  57 #include <sys/dsl_dir.h>
  58 #include <sys/dsl_prop.h>
  59 #include <sys/dsl_synctask.h>
  60 #include <sys/fs/zfs.h>
  61 #include <sys/arc.h>
  62 #include <sys/callb.h>
  63 #include <sys/systeminfo.h>
  64 #include <sys/spa_boot.h>
  65 #include <sys/zfs_ioctl.h>
  66 #include <sys/dsl_scan.h>
  67 #include <sys/zfeature.h>
  68 #include <sys/dsl_destroy.h>
  69 
  70 #ifdef  _KERNEL
  71 #include <sys/bootprops.h>
  72 #include <sys/callb.h>
  73 #include <sys/cpupart.h>
  74 #include <sys/pool.h>
  75 #include <sys/sysdc.h>
  76 #include <sys/zone.h>
  77 #endif  /* _KERNEL */
  78 
  79 #include "zfs_prop.h"
  80 #include "zfs_comutil.h"
  81 
  82 /*
  83  * The interval, in seconds, at which failed configuration cache file writes
  84  * should be retried.
  85  */
  86 static int zfs_ccw_retry_interval = 300;
  87 
  88 typedef enum zti_modes {
  89         ZTI_MODE_FIXED,                 /* value is # of threads (min 1) */
  90         ZTI_MODE_BATCH,                 /* cpu-intensive; value is ignored */
  91         ZTI_MODE_NULL,                  /* don't create a taskq */
  92         ZTI_NMODES
  93 } zti_modes_t;
  94 
  95 #define ZTI_P(n, q)     { ZTI_MODE_FIXED, (n), (q) }
  96 #define ZTI_BATCH       { ZTI_MODE_BATCH, 0, 1 }
  97 #define ZTI_NULL        { ZTI_MODE_NULL, 0, 0 }
  98 
  99 #define ZTI_N(n)        ZTI_P(n, 1)
 100 #define ZTI_ONE         ZTI_N(1)
 101 
 102 typedef struct zio_taskq_info {
 103         zti_modes_t zti_mode;
 104         uint_t zti_value;
 105         uint_t zti_count;
 106 } zio_taskq_info_t;
 107 
 108 static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
 109         "issue", "issue_high", "intr", "intr_high"
 110 };
 111 
 112 /*
 113  * This table defines the taskq settings for each ZFS I/O type. When
 114  * initializing a pool, we use this table to create an appropriately sized
 115  * taskq. Some operations are low volume and therefore have a small, static
 116  * number of threads assigned to their taskqs using the ZTI_N(#) or ZTI_ONE
 117  * macros. Other operations process a large amount of data; the ZTI_BATCH
 118  * macro causes us to create a taskq oriented for throughput. Some operations
 119  * are so high frequency and short-lived that the taskq itself can become a a
 120  * point of lock contention. The ZTI_P(#, #) macro indicates that we need an
 121  * additional degree of parallelism specified by the number of threads per-
 122  * taskq and the number of taskqs; when dispatching an event in this case, the
 123  * particular taskq is chosen at random.
 124  *
 125  * The different taskq priorities are to handle the different contexts (issue
 126  * and interrupt) and then to reserve threads for ZIO_PRIORITY_NOW I/Os that
 127  * need to be handled with minimum delay.
 128  */
 129 const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
 130         /* ISSUE        ISSUE_HIGH      INTR            INTR_HIGH */
 131         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* NULL */
 132         { ZTI_N(8),     ZTI_NULL,       ZTI_P(12, 8),   ZTI_NULL }, /* READ */
 133         { ZTI_BATCH,    ZTI_N(5),       ZTI_N(8),       ZTI_N(5) }, /* WRITE */
 134         { ZTI_P(12, 8), ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* FREE */
 135         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* CLAIM */
 136         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* IOCTL */
 137 };
 138 
 139 static void spa_sync_version(void *arg, dmu_tx_t *tx);
 140 static void spa_sync_props(void *arg, dmu_tx_t *tx);
 141 static boolean_t spa_has_active_shared_spare(spa_t *spa);
 142 static int spa_load_impl(spa_t *spa, uint64_t, nvlist_t *config,
 143     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
 144     char **ereport);
 145 static void spa_vdev_resilver_done(spa_t *spa);
 146 
 147 uint_t          zio_taskq_batch_pct = 75;       /* 1 thread per cpu in pset */
 148 id_t            zio_taskq_psrset_bind = PS_NONE;
 149 boolean_t       zio_taskq_sysdc = B_TRUE;       /* use SDC scheduling class */
 150 uint_t          zio_taskq_basedc = 80;          /* base duty cycle */
 151 
 152 boolean_t       spa_create_process = B_TRUE;    /* no process ==> no sysdc */
 153 extern int      zfs_sync_pass_deferred_free;
 154 
 155 /*
 156  * This (illegal) pool name is used when temporarily importing a spa_t in order
 157  * to get the vdev stats associated with the imported devices.
 158  */
 159 #define TRYIMPORT_NAME  "$import"
 160 
 161 /*
 162  * ==========================================================================
 163  * SPA properties routines
 164  * ==========================================================================
 165  */
 166 
 167 /*
 168  * Add a (source=src, propname=propval) list to an nvlist.
 169  */
 170 static void
 171 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, char *strval,
 172     uint64_t intval, zprop_source_t src)
 173 {
 174         const char *propname = zpool_prop_to_name(prop);
 175         nvlist_t *propval;
 176 
 177         VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 178         VERIFY(nvlist_add_uint64(propval, ZPROP_SOURCE, src) == 0);
 179 
 180         if (strval != NULL)
 181                 VERIFY(nvlist_add_string(propval, ZPROP_VALUE, strval) == 0);
 182         else
 183                 VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, intval) == 0);
 184 
 185         VERIFY(nvlist_add_nvlist(nvl, propname, propval) == 0);
 186         nvlist_free(propval);
 187 }
 188 
 189 /*
 190  * Get property values from the spa configuration.
 191  */
 192 static void
 193 spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
 194 {
 195         vdev_t *rvd = spa->spa_root_vdev;
 196         dsl_pool_t *pool = spa->spa_dsl_pool;
 197         uint64_t size;
 198         uint64_t alloc;
 199         uint64_t space;
 200         uint64_t cap, version;
 201         zprop_source_t src = ZPROP_SRC_NONE;
 202         spa_config_dirent_t *dp;
 203 
 204         ASSERT(MUTEX_HELD(&spa->spa_props_lock));
 205 
 206         if (rvd != NULL) {
 207                 alloc = metaslab_class_get_alloc(spa_normal_class(spa));
 208                 size = metaslab_class_get_space(spa_normal_class(spa));
 209                 spa_prop_add_list(*nvp, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
 210                 spa_prop_add_list(*nvp, ZPOOL_PROP_SIZE, NULL, size, src);
 211                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALLOCATED, NULL, alloc, src);
 212                 spa_prop_add_list(*nvp, ZPOOL_PROP_FREE, NULL,
 213                     size - alloc, src);
 214 
 215                 space = 0;
 216                 for (int c = 0; c < rvd->vdev_children; c++) {
 217                         vdev_t *tvd = rvd->vdev_child[c];
 218                         space += tvd->vdev_max_asize - tvd->vdev_asize;
 219                 }
 220                 spa_prop_add_list(*nvp, ZPOOL_PROP_EXPANDSZ, NULL, space,
 221                     src);
 222 
 223                 spa_prop_add_list(*nvp, ZPOOL_PROP_READONLY, NULL,
 224                     (spa_mode(spa) == FREAD), src);
 225 
 226                 cap = (size == 0) ? 0 : (alloc * 100 / size);
 227                 spa_prop_add_list(*nvp, ZPOOL_PROP_CAPACITY, NULL, cap, src);
 228 
 229                 spa_prop_add_list(*nvp, ZPOOL_PROP_DEDUPRATIO, NULL,
 230                     ddt_get_pool_dedup_ratio(spa), src);
 231 
 232                 spa_prop_add_list(*nvp, ZPOOL_PROP_HEALTH, NULL,
 233                     rvd->vdev_state, src);
 234 
 235                 version = spa_version(spa);
 236                 if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION))
 237                         src = ZPROP_SRC_DEFAULT;
 238                 else
 239                         src = ZPROP_SRC_LOCAL;
 240                 spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL, version, src);
 241         }
 242 
 243         if (pool != NULL) {
 244                 /*
 245                  * The $FREE directory was introduced in SPA_VERSION_DEADLISTS,
 246                  * when opening pools before this version freedir will be NULL.
 247                  */
 248                 if (pool->dp_free_dir != NULL) {
 249                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING, NULL,
 250                             pool->dp_free_dir->dd_phys->dd_used_bytes, src);
 251                 } else {
 252                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING,
 253                             NULL, 0, src);
 254                 }
 255 
 256                 if (pool->dp_leak_dir != NULL) {
 257                         spa_prop_add_list(*nvp, ZPOOL_PROP_LEAKED, NULL,
 258                             pool->dp_leak_dir->dd_phys->dd_used_bytes, src);
 259                 } else {
 260                         spa_prop_add_list(*nvp, ZPOOL_PROP_LEAKED,
 261                             NULL, 0, src);
 262                 }
 263         }
 264 
 265         spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
 266 
 267         if (spa->spa_comment != NULL) {
 268                 spa_prop_add_list(*nvp, ZPOOL_PROP_COMMENT, spa->spa_comment,
 269                     0, ZPROP_SRC_LOCAL);
 270         }
 271 
 272         if (spa->spa_root != NULL)
 273                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
 274                     0, ZPROP_SRC_LOCAL);
 275 
 276         if ((dp = list_head(&spa->spa_config_list)) != NULL) {
 277                 if (dp->scd_path == NULL) {
 278                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 279                             "none", 0, ZPROP_SRC_LOCAL);
 280                 } else if (strcmp(dp->scd_path, spa_config_path) != 0) {
 281                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 282                             dp->scd_path, 0, ZPROP_SRC_LOCAL);
 283                 }
 284         }
 285 }
 286 
 287 /*
 288  * Get zpool property values.
 289  */
 290 int
 291 spa_prop_get(spa_t *spa, nvlist_t **nvp)
 292 {
 293         objset_t *mos = spa->spa_meta_objset;
 294         zap_cursor_t zc;
 295         zap_attribute_t za;
 296         int err;
 297 
 298         VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 299 
 300         mutex_enter(&spa->spa_props_lock);
 301 
 302         /*
 303          * Get properties from the spa config.
 304          */
 305         spa_prop_get_config(spa, nvp);
 306 
 307         /* If no pool property object, no more prop to get. */
 308         if (mos == NULL || spa->spa_pool_props_object == 0) {
 309                 mutex_exit(&spa->spa_props_lock);
 310                 return (0);
 311         }
 312 
 313         /*
 314          * Get properties from the MOS pool property object.
 315          */
 316         for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
 317             (err = zap_cursor_retrieve(&zc, &za)) == 0;
 318             zap_cursor_advance(&zc)) {
 319                 uint64_t intval = 0;
 320                 char *strval = NULL;
 321                 zprop_source_t src = ZPROP_SRC_DEFAULT;
 322                 zpool_prop_t prop;
 323 
 324                 if ((prop = zpool_name_to_prop(za.za_name)) == ZPROP_INVAL)
 325                         continue;
 326 
 327                 switch (za.za_integer_length) {
 328                 case 8:
 329                         /* integer property */
 330                         if (za.za_first_integer !=
 331                             zpool_prop_default_numeric(prop))
 332                                 src = ZPROP_SRC_LOCAL;
 333 
 334                         if (prop == ZPOOL_PROP_BOOTFS) {
 335                                 dsl_pool_t *dp;
 336                                 dsl_dataset_t *ds = NULL;
 337 
 338                                 dp = spa_get_dsl(spa);
 339                                 dsl_pool_config_enter(dp, FTAG);
 340                                 if (err = dsl_dataset_hold_obj(dp,
 341                                     za.za_first_integer, FTAG, &ds)) {
 342                                         dsl_pool_config_exit(dp, FTAG);
 343                                         break;
 344                                 }
 345 
 346                                 strval = kmem_alloc(
 347                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1,
 348                                     KM_SLEEP);
 349                                 dsl_dataset_name(ds, strval);
 350                                 dsl_dataset_rele(ds, FTAG);
 351                                 dsl_pool_config_exit(dp, FTAG);
 352                         } else {
 353                                 strval = NULL;
 354                                 intval = za.za_first_integer;
 355                         }
 356 
 357                         spa_prop_add_list(*nvp, prop, strval, intval, src);
 358 
 359                         if (strval != NULL)
 360                                 kmem_free(strval,
 361                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1);
 362 
 363                         break;
 364 
 365                 case 1:
 366                         /* string property */
 367                         strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
 368                         err = zap_lookup(mos, spa->spa_pool_props_object,
 369                             za.za_name, 1, za.za_num_integers, strval);
 370                         if (err) {
 371                                 kmem_free(strval, za.za_num_integers);
 372                                 break;
 373                         }
 374                         spa_prop_add_list(*nvp, prop, strval, 0, src);
 375                         kmem_free(strval, za.za_num_integers);
 376                         break;
 377 
 378                 default:
 379                         break;
 380                 }
 381         }
 382         zap_cursor_fini(&zc);
 383         mutex_exit(&spa->spa_props_lock);
 384 out:
 385         if (err && err != ENOENT) {
 386                 nvlist_free(*nvp);
 387                 *nvp = NULL;
 388                 return (err);
 389         }
 390 
 391         return (0);
 392 }
 393 
 394 /*
 395  * Validate the given pool properties nvlist and modify the list
 396  * for the property values to be set.
 397  */
 398 static int
 399 spa_prop_validate(spa_t *spa, nvlist_t *props)
 400 {
 401         nvpair_t *elem;
 402         int error = 0, reset_bootfs = 0;
 403         uint64_t objnum = 0;
 404         boolean_t has_feature = B_FALSE;
 405 
 406         elem = NULL;
 407         while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
 408                 uint64_t intval;
 409                 char *strval, *slash, *check, *fname;
 410                 const char *propname = nvpair_name(elem);
 411                 zpool_prop_t prop = zpool_name_to_prop(propname);
 412 
 413                 switch (prop) {
 414                 case ZPROP_INVAL:
 415                         if (!zpool_prop_feature(propname)) {
 416                                 error = SET_ERROR(EINVAL);
 417                                 break;
 418                         }
 419 
 420                         /*
 421                          * Sanitize the input.
 422                          */
 423                         if (nvpair_type(elem) != DATA_TYPE_UINT64) {
 424                                 error = SET_ERROR(EINVAL);
 425                                 break;
 426                         }
 427 
 428                         if (nvpair_value_uint64(elem, &intval) != 0) {
 429                                 error = SET_ERROR(EINVAL);
 430                                 break;
 431                         }
 432 
 433                         if (intval != 0) {
 434                                 error = SET_ERROR(EINVAL);
 435                                 break;
 436                         }
 437 
 438                         fname = strchr(propname, '@') + 1;
 439                         if (zfeature_lookup_name(fname, NULL) != 0) {
 440                                 error = SET_ERROR(EINVAL);
 441                                 break;
 442                         }
 443 
 444                         has_feature = B_TRUE;
 445                         break;
 446 
 447                 case ZPOOL_PROP_VERSION:
 448                         error = nvpair_value_uint64(elem, &intval);
 449                         if (!error &&
 450                             (intval < spa_version(spa) ||
 451                             intval > SPA_VERSION_BEFORE_FEATURES ||
 452                             has_feature))
 453                                 error = SET_ERROR(EINVAL);
 454                         break;
 455 
 456                 case ZPOOL_PROP_DELEGATION:
 457                 case ZPOOL_PROP_AUTOREPLACE:
 458                 case ZPOOL_PROP_LISTSNAPS:
 459                 case ZPOOL_PROP_AUTOEXPAND:
 460                         error = nvpair_value_uint64(elem, &intval);
 461                         if (!error && intval > 1)
 462                                 error = SET_ERROR(EINVAL);
 463                         break;
 464 
 465                 case ZPOOL_PROP_BOOTFS:
 466                         /*
 467                          * If the pool version is less than SPA_VERSION_BOOTFS,
 468                          * or the pool is still being created (version == 0),
 469                          * the bootfs property cannot be set.
 470                          */
 471                         if (spa_version(spa) < SPA_VERSION_BOOTFS) {
 472                                 error = SET_ERROR(ENOTSUP);
 473                                 break;
 474                         }
 475 
 476                         /*
 477                          * Make sure the vdev config is bootable
 478                          */
 479                         if (!vdev_is_bootable(spa->spa_root_vdev)) {
 480                                 error = SET_ERROR(ENOTSUP);
 481                                 break;
 482                         }
 483 
 484                         reset_bootfs = 1;
 485 
 486                         error = nvpair_value_string(elem, &strval);
 487 
 488                         if (!error) {
 489                                 objset_t *os;
 490                                 uint64_t compress;
 491 
 492                                 if (strval == NULL || strval[0] == '\0') {
 493                                         objnum = zpool_prop_default_numeric(
 494                                             ZPOOL_PROP_BOOTFS);
 495                                         break;
 496                                 }
 497 
 498                                 if (error = dmu_objset_hold(strval, FTAG, &os))
 499                                         break;
 500 
 501                                 /* Must be ZPL and not gzip compressed. */
 502 
 503                                 if (dmu_objset_type(os) != DMU_OST_ZFS) {
 504                                         error = SET_ERROR(ENOTSUP);
 505                                 } else if ((error =
 506                                     dsl_prop_get_int_ds(dmu_objset_ds(os),
 507                                     zfs_prop_to_name(ZFS_PROP_COMPRESSION),
 508                                     &compress)) == 0 &&
 509                                     !BOOTFS_COMPRESS_VALID(compress)) {
 510                                         error = SET_ERROR(ENOTSUP);
 511                                 } else {
 512                                         objnum = dmu_objset_id(os);
 513                                 }
 514                                 dmu_objset_rele(os, FTAG);
 515                         }
 516                         break;
 517 
 518                 case ZPOOL_PROP_FAILUREMODE:
 519                         error = nvpair_value_uint64(elem, &intval);
 520                         if (!error && (intval < ZIO_FAILURE_MODE_WAIT ||
 521                             intval > ZIO_FAILURE_MODE_PANIC))
 522                                 error = SET_ERROR(EINVAL);
 523 
 524                         /*
 525                          * This is a special case which only occurs when
 526                          * the pool has completely failed. This allows
 527                          * the user to change the in-core failmode property
 528                          * without syncing it out to disk (I/Os might
 529                          * currently be blocked). We do this by returning
 530                          * EIO to the caller (spa_prop_set) to trick it
 531                          * into thinking we encountered a property validation
 532                          * error.
 533                          */
 534                         if (!error && spa_suspended(spa)) {
 535                                 spa->spa_failmode = intval;
 536                                 error = SET_ERROR(EIO);
 537                         }
 538                         break;
 539 
 540                 case ZPOOL_PROP_CACHEFILE:
 541                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 542                                 break;
 543 
 544                         if (strval[0] == '\0')
 545                                 break;
 546 
 547                         if (strcmp(strval, "none") == 0)
 548                                 break;
 549 
 550                         if (strval[0] != '/') {
 551                                 error = SET_ERROR(EINVAL);
 552                                 break;
 553                         }
 554 
 555                         slash = strrchr(strval, '/');
 556                         ASSERT(slash != NULL);
 557 
 558                         if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
 559                             strcmp(slash, "/..") == 0)
 560                                 error = SET_ERROR(EINVAL);
 561                         break;
 562 
 563                 case ZPOOL_PROP_COMMENT:
 564                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 565                                 break;
 566                         for (check = strval; *check != '\0'; check++) {
 567                                 /*
 568                                  * The kernel doesn't have an easy isprint()
 569                                  * check.  For this kernel check, we merely
 570                                  * check ASCII apart from DEL.  Fix this if
 571                                  * there is an easy-to-use kernel isprint().
 572                                  */
 573                                 if (*check >= 0x7f) {
 574                                         error = SET_ERROR(EINVAL);
 575                                         break;
 576                                 }
 577                                 check++;
 578                         }
 579                         if (strlen(strval) > ZPROP_MAX_COMMENT)
 580                                 error = E2BIG;
 581                         break;
 582 
 583                 case ZPOOL_PROP_DEDUPDITTO:
 584                         if (spa_version(spa) < SPA_VERSION_DEDUP)
 585                                 error = SET_ERROR(ENOTSUP);
 586                         else
 587                                 error = nvpair_value_uint64(elem, &intval);
 588                         if (error == 0 &&
 589                             intval != 0 && intval < ZIO_DEDUPDITTO_MIN)
 590                                 error = SET_ERROR(EINVAL);
 591                         break;
 592                 }
 593 
 594                 if (error)
 595                         break;
 596         }
 597 
 598         if (!error && reset_bootfs) {
 599                 error = nvlist_remove(props,
 600                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
 601 
 602                 if (!error) {
 603                         error = nvlist_add_uint64(props,
 604                             zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
 605                 }
 606         }
 607 
 608         return (error);
 609 }
 610 
 611 void
 612 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
 613 {
 614         char *cachefile;
 615         spa_config_dirent_t *dp;
 616 
 617         if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
 618             &cachefile) != 0)
 619                 return;
 620 
 621         dp = kmem_alloc(sizeof (spa_config_dirent_t),
 622             KM_SLEEP);
 623 
 624         if (cachefile[0] == '\0')
 625                 dp->scd_path = spa_strdup(spa_config_path);
 626         else if (strcmp(cachefile, "none") == 0)
 627                 dp->scd_path = NULL;
 628         else
 629                 dp->scd_path = spa_strdup(cachefile);
 630 
 631         list_insert_head(&spa->spa_config_list, dp);
 632         if (need_sync)
 633                 spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
 634 }
 635 
 636 int
 637 spa_prop_set(spa_t *spa, nvlist_t *nvp)
 638 {
 639         int error;
 640         nvpair_t *elem = NULL;
 641         boolean_t need_sync = B_FALSE;
 642 
 643         if ((error = spa_prop_validate(spa, nvp)) != 0)
 644                 return (error);
 645 
 646         while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
 647                 zpool_prop_t prop = zpool_name_to_prop(nvpair_name(elem));
 648 
 649                 if (prop == ZPOOL_PROP_CACHEFILE ||
 650                     prop == ZPOOL_PROP_ALTROOT ||
 651                     prop == ZPOOL_PROP_READONLY)
 652                         continue;
 653 
 654                 if (prop == ZPOOL_PROP_VERSION || prop == ZPROP_INVAL) {
 655                         uint64_t ver;
 656 
 657                         if (prop == ZPOOL_PROP_VERSION) {
 658                                 VERIFY(nvpair_value_uint64(elem, &ver) == 0);
 659                         } else {
 660                                 ASSERT(zpool_prop_feature(nvpair_name(elem)));
 661                                 ver = SPA_VERSION_FEATURES;
 662                                 need_sync = B_TRUE;
 663                         }
 664 
 665                         /* Save time if the version is already set. */
 666                         if (ver == spa_version(spa))
 667                                 continue;
 668 
 669                         /*
 670                          * In addition to the pool directory object, we might
 671                          * create the pool properties object, the features for
 672                          * read object, the features for write object, or the
 673                          * feature descriptions object.
 674                          */
 675                         error = dsl_sync_task(spa->spa_name, NULL,
 676                             spa_sync_version, &ver, 6);
 677                         if (error)
 678                                 return (error);
 679                         continue;
 680                 }
 681 
 682                 need_sync = B_TRUE;
 683                 break;
 684         }
 685 
 686         if (need_sync) {
 687                 return (dsl_sync_task(spa->spa_name, NULL, spa_sync_props,
 688                     nvp, 6));
 689         }
 690 
 691         return (0);
 692 }
 693 
 694 /*
 695  * If the bootfs property value is dsobj, clear it.
 696  */
 697 void
 698 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
 699 {
 700         if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
 701                 VERIFY(zap_remove(spa->spa_meta_objset,
 702                     spa->spa_pool_props_object,
 703                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
 704                 spa->spa_bootfs = 0;
 705         }
 706 }
 707 
 708 /*ARGSUSED*/
 709 static int
 710 spa_change_guid_check(void *arg, dmu_tx_t *tx)
 711 {
 712         uint64_t *newguid = arg;
 713         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 714         vdev_t *rvd = spa->spa_root_vdev;
 715         uint64_t vdev_state;
 716 
 717         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
 718         vdev_state = rvd->vdev_state;
 719         spa_config_exit(spa, SCL_STATE, FTAG);
 720 
 721         if (vdev_state != VDEV_STATE_HEALTHY)
 722                 return (SET_ERROR(ENXIO));
 723 
 724         ASSERT3U(spa_guid(spa), !=, *newguid);
 725 
 726         return (0);
 727 }
 728 
 729 static void
 730 spa_change_guid_sync(void *arg, dmu_tx_t *tx)
 731 {
 732         uint64_t *newguid = arg;
 733         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 734         uint64_t oldguid;
 735         vdev_t *rvd = spa->spa_root_vdev;
 736 
 737         oldguid = spa_guid(spa);
 738 
 739         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
 740         rvd->vdev_guid = *newguid;
 741         rvd->vdev_guid_sum += (*newguid - oldguid);
 742         vdev_config_dirty(rvd);
 743         spa_config_exit(spa, SCL_STATE, FTAG);
 744 
 745         spa_history_log_internal(spa, "guid change", tx, "old=%llu new=%llu",
 746             oldguid, *newguid);
 747 }
 748 
 749 /*
 750  * Change the GUID for the pool.  This is done so that we can later
 751  * re-import a pool built from a clone of our own vdevs.  We will modify
 752  * the root vdev's guid, our own pool guid, and then mark all of our
 753  * vdevs dirty.  Note that we must make sure that all our vdevs are
 754  * online when we do this, or else any vdevs that weren't present
 755  * would be orphaned from our pool.  We are also going to issue a
 756  * sysevent to update any watchers.
 757  */
 758 int
 759 spa_change_guid(spa_t *spa)
 760 {
 761         int error;
 762         uint64_t guid;
 763 
 764         mutex_enter(&spa->spa_vdev_top_lock);
 765         mutex_enter(&spa_namespace_lock);
 766         guid = spa_generate_guid(NULL);
 767 
 768         error = dsl_sync_task(spa->spa_name, spa_change_guid_check,
 769             spa_change_guid_sync, &guid, 5);
 770 
 771         if (error == 0) {
 772                 spa_config_sync(spa, B_FALSE, B_TRUE);
 773                 spa_event_notify(spa, NULL, ESC_ZFS_POOL_REGUID);
 774         }
 775 
 776         mutex_exit(&spa_namespace_lock);
 777         mutex_exit(&spa->spa_vdev_top_lock);
 778 
 779         return (error);
 780 }
 781 
 782 /*
 783  * ==========================================================================
 784  * SPA state manipulation (open/create/destroy/import/export)
 785  * ==========================================================================
 786  */
 787 
 788 static int
 789 spa_error_entry_compare(const void *a, const void *b)
 790 {
 791         spa_error_entry_t *sa = (spa_error_entry_t *)a;
 792         spa_error_entry_t *sb = (spa_error_entry_t *)b;
 793         int ret;
 794 
 795         ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
 796             sizeof (zbookmark_t));
 797 
 798         if (ret < 0)
 799                 return (-1);
 800         else if (ret > 0)
 801                 return (1);
 802         else
 803                 return (0);
 804 }
 805 
 806 /*
 807  * Utility function which retrieves copies of the current logs and
 808  * re-initializes them in the process.
 809  */
 810 void
 811 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
 812 {
 813         ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
 814 
 815         bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
 816         bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));
 817 
 818         avl_create(&spa->spa_errlist_scrub,
 819             spa_error_entry_compare, sizeof (spa_error_entry_t),
 820             offsetof(spa_error_entry_t, se_avl));
 821         avl_create(&spa->spa_errlist_last,
 822             spa_error_entry_compare, sizeof (spa_error_entry_t),
 823             offsetof(spa_error_entry_t, se_avl));
 824 }
 825 
 826 static void
 827 spa_taskqs_init(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
 828 {
 829         const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
 830         enum zti_modes mode = ztip->zti_mode;
 831         uint_t value = ztip->zti_value;
 832         uint_t count = ztip->zti_count;
 833         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 834         char name[32];
 835         uint_t flags = 0;
 836         boolean_t batch = B_FALSE;
 837 
 838         if (mode == ZTI_MODE_NULL) {
 839                 tqs->stqs_count = 0;
 840                 tqs->stqs_taskq = NULL;
 841                 return;
 842         }
 843 
 844         ASSERT3U(count, >, 0);
 845 
 846         tqs->stqs_count = count;
 847         tqs->stqs_taskq = kmem_alloc(count * sizeof (taskq_t *), KM_SLEEP);
 848 
 849         switch (mode) {
 850         case ZTI_MODE_FIXED:
 851                 ASSERT3U(value, >=, 1);
 852                 value = MAX(value, 1);
 853                 break;
 854 
 855         case ZTI_MODE_BATCH:
 856                 batch = B_TRUE;
 857                 flags |= TASKQ_THREADS_CPU_PCT;
 858                 value = zio_taskq_batch_pct;
 859                 break;
 860 
 861         default:
 862                 panic("unrecognized mode for %s_%s taskq (%u:%u) in "
 863                     "spa_activate()",
 864                     zio_type_name[t], zio_taskq_types[q], mode, value);
 865                 break;
 866         }
 867 
 868         for (uint_t i = 0; i < count; i++) {
 869                 taskq_t *tq;
 870 
 871                 if (count > 1) {
 872                         (void) snprintf(name, sizeof (name), "%s_%s_%u",
 873                             zio_type_name[t], zio_taskq_types[q], i);
 874                 } else {
 875                         (void) snprintf(name, sizeof (name), "%s_%s",
 876                             zio_type_name[t], zio_taskq_types[q]);
 877                 }
 878 
 879                 if (zio_taskq_sysdc && spa->spa_proc != &p0) {
 880                         if (batch)
 881                                 flags |= TASKQ_DC_BATCH;
 882 
 883                         tq = taskq_create_sysdc(name, value, 50, INT_MAX,
 884                             spa->spa_proc, zio_taskq_basedc, flags);
 885                 } else {
 886                         pri_t pri = maxclsyspri;
 887                         /*
 888                          * The write issue taskq can be extremely CPU
 889                          * intensive.  Run it at slightly lower priority
 890                          * than the other taskqs.
 891                          */
 892                         if (t == ZIO_TYPE_WRITE && q == ZIO_TASKQ_ISSUE)
 893                                 pri--;
 894 
 895                         tq = taskq_create_proc(name, value, pri, 50,
 896                             INT_MAX, spa->spa_proc, flags);
 897                 }
 898 
 899                 tqs->stqs_taskq[i] = tq;
 900         }
 901 }
 902 
 903 static void
 904 spa_taskqs_fini(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
 905 {
 906         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 907 
 908         if (tqs->stqs_taskq == NULL) {
 909                 ASSERT0(tqs->stqs_count);
 910                 return;
 911         }
 912 
 913         for (uint_t i = 0; i < tqs->stqs_count; i++) {
 914                 ASSERT3P(tqs->stqs_taskq[i], !=, NULL);
 915                 taskq_destroy(tqs->stqs_taskq[i]);
 916         }
 917 
 918         kmem_free(tqs->stqs_taskq, tqs->stqs_count * sizeof (taskq_t *));
 919         tqs->stqs_taskq = NULL;
 920 }
 921 
 922 /*
 923  * Dispatch a task to the appropriate taskq for the ZFS I/O type and priority.
 924  * Note that a type may have multiple discrete taskqs to avoid lock contention
 925  * on the taskq itself. In that case we choose which taskq at random by using
 926  * the low bits of gethrtime().
 927  */
 928 void
 929 spa_taskq_dispatch_ent(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
 930     task_func_t *func, void *arg, uint_t flags, taskq_ent_t *ent)
 931 {
 932         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 933         taskq_t *tq;
 934 
 935         ASSERT3P(tqs->stqs_taskq, !=, NULL);
 936         ASSERT3U(tqs->stqs_count, !=, 0);
 937 
 938         if (tqs->stqs_count == 1) {
 939                 tq = tqs->stqs_taskq[0];
 940         } else {
 941                 tq = tqs->stqs_taskq[gethrtime() % tqs->stqs_count];
 942         }
 943 
 944         taskq_dispatch_ent(tq, func, arg, flags, ent);
 945 }
 946 
 947 static void
 948 spa_create_zio_taskqs(spa_t *spa)
 949 {
 950         for (int t = 0; t < ZIO_TYPES; t++) {
 951                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
 952                         spa_taskqs_init(spa, t, q);
 953                 }
 954         }
 955 }
 956 
 957 #ifdef _KERNEL
 958 static void
 959 spa_thread(void *arg)
 960 {
 961         callb_cpr_t cprinfo;
 962 
 963         spa_t *spa = arg;
 964         user_t *pu = PTOU(curproc);
 965 
 966         CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
 967             spa->spa_name);
 968 
 969         ASSERT(curproc != &p0);
 970         (void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
 971             "zpool-%s", spa->spa_name);
 972         (void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
 973 
 974         /* bind this thread to the requested psrset */
 975         if (zio_taskq_psrset_bind != PS_NONE) {
 976                 pool_lock();
 977                 mutex_enter(&cpu_lock);
 978                 mutex_enter(&pidlock);
 979                 mutex_enter(&curproc->p_lock);
 980 
 981                 if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
 982                     0, NULL, NULL) == 0)  {
 983                         curthread->t_bind_pset = zio_taskq_psrset_bind;
 984                 } else {
 985                         cmn_err(CE_WARN,
 986                             "Couldn't bind process for zfs pool \"%s\" to "
 987                             "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
 988                 }
 989 
 990                 mutex_exit(&curproc->p_lock);
 991                 mutex_exit(&pidlock);
 992                 mutex_exit(&cpu_lock);
 993                 pool_unlock();
 994         }
 995 
 996         if (zio_taskq_sysdc) {
 997                 sysdc_thread_enter(curthread, 100, 0);
 998         }
 999 
1000         spa->spa_proc = curproc;
1001         spa->spa_did = curthread->t_did;
1002 
1003         spa_create_zio_taskqs(spa);
1004 
1005         mutex_enter(&spa->spa_proc_lock);
1006         ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
1007 
1008         spa->spa_proc_state = SPA_PROC_ACTIVE;
1009         cv_broadcast(&spa->spa_proc_cv);
1010 
1011         CALLB_CPR_SAFE_BEGIN(&cprinfo);
1012         while (spa->spa_proc_state == SPA_PROC_ACTIVE)
1013                 cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1014         CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
1015 
1016         ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
1017         spa->spa_proc_state = SPA_PROC_GONE;
1018         spa->spa_proc = &p0;
1019         cv_broadcast(&spa->spa_proc_cv);
1020         CALLB_CPR_EXIT(&cprinfo);   /* drops spa_proc_lock */
1021 
1022         mutex_enter(&curproc->p_lock);
1023         lwp_exit();
1024 }
1025 #endif
1026 
1027 /*
1028  * Activate an uninitialized pool.
1029  */
1030 static void
1031 spa_activate(spa_t *spa, int mode)
1032 {
1033         ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
1034 
1035         spa->spa_state = POOL_STATE_ACTIVE;
1036         spa->spa_mode = mode;
1037 
1038         spa->spa_normal_class = metaslab_class_create(spa, zfs_metaslab_ops);
1039         spa->spa_log_class = metaslab_class_create(spa, zfs_metaslab_ops);
1040 
1041         /* Try to create a covering process */
1042         mutex_enter(&spa->spa_proc_lock);
1043         ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
1044         ASSERT(spa->spa_proc == &p0);
1045         spa->spa_did = 0;
1046 
1047         /* Only create a process if we're going to be around a while. */
1048         if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
1049                 if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
1050                     NULL, 0) == 0) {
1051                         spa->spa_proc_state = SPA_PROC_CREATED;
1052                         while (spa->spa_proc_state == SPA_PROC_CREATED) {
1053                                 cv_wait(&spa->spa_proc_cv,
1054                                     &spa->spa_proc_lock);
1055                         }
1056                         ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1057                         ASSERT(spa->spa_proc != &p0);
1058                         ASSERT(spa->spa_did != 0);
1059                 } else {
1060 #ifdef _KERNEL
1061                         cmn_err(CE_WARN,
1062                             "Couldn't create process for zfs pool \"%s\"\n",
1063                             spa->spa_name);
1064 #endif
1065                 }
1066         }
1067         mutex_exit(&spa->spa_proc_lock);
1068 
1069         /* If we didn't create a process, we need to create our taskqs. */
1070         if (spa->spa_proc == &p0) {
1071                 spa_create_zio_taskqs(spa);
1072         }
1073 
1074         list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
1075             offsetof(vdev_t, vdev_config_dirty_node));
1076         list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
1077             offsetof(vdev_t, vdev_state_dirty_node));
1078 
1079         txg_list_create(&spa->spa_vdev_txg_list,
1080             offsetof(struct vdev, vdev_txg_node));
1081 
1082         avl_create(&spa->spa_errlist_scrub,
1083             spa_error_entry_compare, sizeof (spa_error_entry_t),
1084             offsetof(spa_error_entry_t, se_avl));
1085         avl_create(&spa->spa_errlist_last,
1086             spa_error_entry_compare, sizeof (spa_error_entry_t),
1087             offsetof(spa_error_entry_t, se_avl));
1088 }
1089 
1090 /*
1091  * Opposite of spa_activate().
1092  */
1093 static void
1094 spa_deactivate(spa_t *spa)
1095 {
1096         ASSERT(spa->spa_sync_on == B_FALSE);
1097         ASSERT(spa->spa_dsl_pool == NULL);
1098         ASSERT(spa->spa_root_vdev == NULL);
1099         ASSERT(spa->spa_async_zio_root == NULL);
1100         ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
1101 
1102         txg_list_destroy(&spa->spa_vdev_txg_list);
1103 
1104         list_destroy(&spa->spa_config_dirty_list);
1105         list_destroy(&spa->spa_state_dirty_list);
1106 
1107         for (int t = 0; t < ZIO_TYPES; t++) {
1108                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
1109                         spa_taskqs_fini(spa, t, q);
1110                 }
1111         }
1112 
1113         metaslab_class_destroy(spa->spa_normal_class);
1114         spa->spa_normal_class = NULL;
1115 
1116         metaslab_class_destroy(spa->spa_log_class);
1117         spa->spa_log_class = NULL;
1118 
1119         /*
1120          * If this was part of an import or the open otherwise failed, we may
1121          * still have errors left in the queues.  Empty them just in case.
1122          */
1123         spa_errlog_drain(spa);
1124 
1125         avl_destroy(&spa->spa_errlist_scrub);
1126         avl_destroy(&spa->spa_errlist_last);
1127 
1128         spa->spa_state = POOL_STATE_UNINITIALIZED;
1129 
1130         mutex_enter(&spa->spa_proc_lock);
1131         if (spa->spa_proc_state != SPA_PROC_NONE) {
1132                 ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1133                 spa->spa_proc_state = SPA_PROC_DEACTIVATE;
1134                 cv_broadcast(&spa->spa_proc_cv);
1135                 while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
1136                         ASSERT(spa->spa_proc != &p0);
1137                         cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1138                 }
1139                 ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
1140                 spa->spa_proc_state = SPA_PROC_NONE;
1141         }
1142         ASSERT(spa->spa_proc == &p0);
1143         mutex_exit(&spa->spa_proc_lock);
1144 
1145         /*
1146          * We want to make sure spa_thread() has actually exited the ZFS
1147          * module, so that the module can't be unloaded out from underneath
1148          * it.
1149          */
1150         if (spa->spa_did != 0) {
1151                 thread_join(spa->spa_did);
1152                 spa->spa_did = 0;
1153         }
1154 }
1155 
1156 /*
1157  * Verify a pool configuration, and construct the vdev tree appropriately.  This
1158  * will create all the necessary vdevs in the appropriate layout, with each vdev
1159  * in the CLOSED state.  This will prep the pool before open/creation/import.
1160  * All vdev validation is done by the vdev_alloc() routine.
1161  */
1162 static int
1163 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
1164     uint_t id, int atype)
1165 {
1166         nvlist_t **child;
1167         uint_t children;
1168         int error;
1169 
1170         if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
1171                 return (error);
1172 
1173         if ((*vdp)->vdev_ops->vdev_op_leaf)
1174                 return (0);
1175 
1176         error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
1177             &child, &children);
1178 
1179         if (error == ENOENT)
1180                 return (0);
1181 
1182         if (error) {
1183                 vdev_free(*vdp);
1184                 *vdp = NULL;
1185                 return (SET_ERROR(EINVAL));
1186         }
1187 
1188         for (int c = 0; c < children; c++) {
1189                 vdev_t *vd;
1190                 if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
1191                     atype)) != 0) {
1192                         vdev_free(*vdp);
1193                         *vdp = NULL;
1194                         return (error);
1195                 }
1196         }
1197 
1198         ASSERT(*vdp != NULL);
1199 
1200         return (0);
1201 }
1202 
1203 /*
1204  * Opposite of spa_load().
1205  */
1206 static void
1207 spa_unload(spa_t *spa)
1208 {
1209         int i;
1210 
1211         ASSERT(MUTEX_HELD(&spa_namespace_lock));
1212 
1213         /*
1214          * Stop async tasks.
1215          */
1216         spa_async_suspend(spa);
1217 
1218         /*
1219          * Stop syncing.
1220          */
1221         if (spa->spa_sync_on) {
1222                 txg_sync_stop(spa->spa_dsl_pool);
1223                 spa->spa_sync_on = B_FALSE;
1224         }
1225 
1226         /*
1227          * Wait for any outstanding async I/O to complete.
1228          */
1229         if (spa->spa_async_zio_root != NULL) {
1230                 (void) zio_wait(spa->spa_async_zio_root);
1231                 spa->spa_async_zio_root = NULL;
1232         }
1233 
1234         bpobj_close(&spa->spa_deferred_bpobj);
1235 
1236         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1237 
1238         /*
1239          * Close all vdevs.
1240          */
1241         if (spa->spa_root_vdev)
1242                 vdev_free(spa->spa_root_vdev);
1243         ASSERT(spa->spa_root_vdev == NULL);
1244 
1245         /*
1246          * Close the dsl pool.
1247          */
1248         if (spa->spa_dsl_pool) {
1249                 dsl_pool_close(spa->spa_dsl_pool);
1250                 spa->spa_dsl_pool = NULL;
1251                 spa->spa_meta_objset = NULL;
1252         }
1253 
1254         ddt_unload(spa);
1255 
1256 
1257         /*
1258          * Drop and purge level 2 cache
1259          */
1260         spa_l2cache_drop(spa);
1261 
1262         for (i = 0; i < spa->spa_spares.sav_count; i++)
1263                 vdev_free(spa->spa_spares.sav_vdevs[i]);
1264         if (spa->spa_spares.sav_vdevs) {
1265                 kmem_free(spa->spa_spares.sav_vdevs,
1266                     spa->spa_spares.sav_count * sizeof (void *));
1267                 spa->spa_spares.sav_vdevs = NULL;
1268         }
1269         if (spa->spa_spares.sav_config) {
1270                 nvlist_free(spa->spa_spares.sav_config);
1271                 spa->spa_spares.sav_config = NULL;
1272         }
1273         spa->spa_spares.sav_count = 0;
1274 
1275         for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
1276                 vdev_clear_stats(spa->spa_l2cache.sav_vdevs[i]);
1277                 vdev_free(spa->spa_l2cache.sav_vdevs[i]);
1278         }
1279         if (spa->spa_l2cache.sav_vdevs) {
1280                 kmem_free(spa->spa_l2cache.sav_vdevs,
1281                     spa->spa_l2cache.sav_count * sizeof (void *));
1282                 spa->spa_l2cache.sav_vdevs = NULL;
1283         }
1284         if (spa->spa_l2cache.sav_config) {
1285                 nvlist_free(spa->spa_l2cache.sav_config);
1286                 spa->spa_l2cache.sav_config = NULL;
1287         }
1288         spa->spa_l2cache.sav_count = 0;
1289 
1290         spa->spa_async_suspended = 0;
1291 
1292         if (spa->spa_comment != NULL) {
1293                 spa_strfree(spa->spa_comment);
1294                 spa->spa_comment = NULL;
1295         }
1296 
1297         spa_config_exit(spa, SCL_ALL, FTAG);
1298 }
1299 
1300 /*
1301  * Load (or re-load) the current list of vdevs describing the active spares for
1302  * this pool.  When this is called, we have some form of basic information in
1303  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
1304  * then re-generate a more complete list including status information.
1305  */
1306 static void
1307 spa_load_spares(spa_t *spa)
1308 {
1309         nvlist_t **spares;
1310         uint_t nspares;
1311         int i;
1312         vdev_t *vd, *tvd;
1313 
1314         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1315 
1316         /*
1317          * First, close and free any existing spare vdevs.
1318          */
1319         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1320                 vd = spa->spa_spares.sav_vdevs[i];
1321 
1322                 /* Undo the call to spa_activate() below */
1323                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1324                     B_FALSE)) != NULL && tvd->vdev_isspare)
1325                         spa_spare_remove(tvd);
1326                 vdev_close(vd);
1327                 vdev_free(vd);
1328         }
1329 
1330         if (spa->spa_spares.sav_vdevs)
1331                 kmem_free(spa->spa_spares.sav_vdevs,
1332                     spa->spa_spares.sav_count * sizeof (void *));
1333 
1334         if (spa->spa_spares.sav_config == NULL)
1335                 nspares = 0;
1336         else
1337                 VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1338                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1339 
1340         spa->spa_spares.sav_count = (int)nspares;
1341         spa->spa_spares.sav_vdevs = NULL;
1342 
1343         if (nspares == 0)
1344                 return;
1345 
1346         /*
1347          * Construct the array of vdevs, opening them to get status in the
1348          * process.   For each spare, there is potentially two different vdev_t
1349          * structures associated with it: one in the list of spares (used only
1350          * for basic validation purposes) and one in the active vdev
1351          * configuration (if it's spared in).  During this phase we open and
1352          * validate each vdev on the spare list.  If the vdev also exists in the
1353          * active configuration, then we also mark this vdev as an active spare.
1354          */
1355         spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
1356             KM_SLEEP);
1357         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1358                 VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
1359                     VDEV_ALLOC_SPARE) == 0);
1360                 ASSERT(vd != NULL);
1361 
1362                 spa->spa_spares.sav_vdevs[i] = vd;
1363 
1364                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1365                     B_FALSE)) != NULL) {
1366                         if (!tvd->vdev_isspare)
1367                                 spa_spare_add(tvd);
1368 
1369                         /*
1370                          * We only mark the spare active if we were successfully
1371                          * able to load the vdev.  Otherwise, importing a pool
1372                          * with a bad active spare would result in strange
1373                          * behavior, because multiple pool would think the spare
1374                          * is actively in use.
1375                          *
1376                          * There is a vulnerability here to an equally bizarre
1377                          * circumstance, where a dead active spare is later
1378                          * brought back to life (onlined or otherwise).  Given
1379                          * the rarity of this scenario, and the extra complexity
1380                          * it adds, we ignore the possibility.
1381                          */
1382                         if (!vdev_is_dead(tvd))
1383                                 spa_spare_activate(tvd);
1384                 }
1385 
1386                 vd->vdev_top = vd;
1387                 vd->vdev_aux = &spa->spa_spares;
1388 
1389                 if (vdev_open(vd) != 0)
1390                         continue;
1391 
1392                 if (vdev_validate_aux(vd) == 0)
1393                         spa_spare_add(vd);
1394         }
1395 
1396         /*
1397          * Recompute the stashed list of spares, with status information
1398          * this time.
1399          */
1400         VERIFY(nvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES,
1401             DATA_TYPE_NVLIST_ARRAY) == 0);
1402 
1403         spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
1404             KM_SLEEP);
1405         for (i = 0; i < spa->spa_spares.sav_count; i++)
1406                 spares[i] = vdev_config_generate(spa,
1407                     spa->spa_spares.sav_vdevs[i], B_TRUE, VDEV_CONFIG_SPARE);
1408         VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
1409             ZPOOL_CONFIG_SPARES, spares, spa->spa_spares.sav_count) == 0);
1410         for (i = 0; i < spa->spa_spares.sav_count; i++)
1411                 nvlist_free(spares[i]);
1412         kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
1413 }
1414 
1415 /*
1416  * Load (or re-load) the current list of vdevs describing the active l2cache for
1417  * this pool.  When this is called, we have some form of basic information in
1418  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
1419  * then re-generate a more complete list including status information.
1420  * Devices which are already active have their details maintained, and are
1421  * not re-opened.
1422  */
1423 static void
1424 spa_load_l2cache(spa_t *spa)
1425 {
1426         nvlist_t **l2cache;
1427         uint_t nl2cache;
1428         int i, j, oldnvdevs;
1429         uint64_t guid;
1430         vdev_t *vd, **oldvdevs, **newvdevs;
1431         spa_aux_vdev_t *sav = &spa->spa_l2cache;
1432 
1433         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1434 
1435         if (sav->sav_config != NULL) {
1436                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
1437                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1438                 newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
1439         } else {
1440                 nl2cache = 0;
1441                 newvdevs = NULL;
1442         }
1443 
1444         oldvdevs = sav->sav_vdevs;
1445         oldnvdevs = sav->sav_count;
1446         sav->sav_vdevs = NULL;
1447         sav->sav_count = 0;
1448 
1449         /*
1450          * Process new nvlist of vdevs.
1451          */
1452         for (i = 0; i < nl2cache; i++) {
1453                 VERIFY(nvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID,
1454                     &guid) == 0);
1455 
1456                 newvdevs[i] = NULL;
1457                 for (j = 0; j < oldnvdevs; j++) {
1458                         vd = oldvdevs[j];
1459                         if (vd != NULL && guid == vd->vdev_guid) {
1460                                 /*
1461                                  * Retain previous vdev for add/remove ops.
1462                                  */
1463                                 newvdevs[i] = vd;
1464                                 oldvdevs[j] = NULL;
1465                                 break;
1466                         }
1467                 }
1468 
1469                 if (newvdevs[i] == NULL) {
1470                         /*
1471                          * Create new vdev
1472                          */
1473                         VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
1474                             VDEV_ALLOC_L2CACHE) == 0);
1475                         ASSERT(vd != NULL);
1476                         newvdevs[i] = vd;
1477 
1478                         /*
1479                          * Commit this vdev as an l2cache device,
1480                          * even if it fails to open.
1481                          */
1482                         spa_l2cache_add(vd);
1483 
1484                         vd->vdev_top = vd;
1485                         vd->vdev_aux = sav;
1486 
1487                         spa_l2cache_activate(vd);
1488 
1489                         if (vdev_open(vd) != 0)
1490                                 continue;
1491 
1492                         (void) vdev_validate_aux(vd);
1493 
1494                         if (!vdev_is_dead(vd))
1495                                 l2arc_add_vdev(spa, vd);
1496                 }
1497         }
1498 
1499         /*
1500          * Purge vdevs that were dropped
1501          */
1502         for (i = 0; i < oldnvdevs; i++) {
1503                 uint64_t pool;
1504 
1505                 vd = oldvdevs[i];
1506                 if (vd != NULL) {
1507                         ASSERT(vd->vdev_isl2cache);
1508 
1509                         if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
1510                             pool != 0ULL && l2arc_vdev_present(vd))
1511                                 l2arc_remove_vdev(vd);
1512                         vdev_clear_stats(vd);
1513                         vdev_free(vd);
1514                 }
1515         }
1516 
1517         if (oldvdevs)
1518                 kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
1519 
1520         if (sav->sav_config == NULL)
1521                 goto out;
1522 
1523         sav->sav_vdevs = newvdevs;
1524         sav->sav_count = (int)nl2cache;
1525 
1526         /*
1527          * Recompute the stashed list of l2cache devices, with status
1528          * information this time.
1529          */
1530         VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
1531             DATA_TYPE_NVLIST_ARRAY) == 0);
1532 
1533         l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
1534         for (i = 0; i < sav->sav_count; i++)
1535                 l2cache[i] = vdev_config_generate(spa,
1536                     sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);
1537         VERIFY(nvlist_add_nvlist_array(sav->sav_config,
1538             ZPOOL_CONFIG_L2CACHE, l2cache, sav->sav_count) == 0);
1539 out:
1540         for (i = 0; i < sav->sav_count; i++)
1541                 nvlist_free(l2cache[i]);
1542         if (sav->sav_count)
1543                 kmem_free(l2cache, sav->sav_count * sizeof (void *));
1544 }
1545 
1546 static int
1547 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
1548 {
1549         dmu_buf_t *db;
1550         char *packed = NULL;
1551         size_t nvsize = 0;
1552         int error;
1553         *value = NULL;
1554 
1555         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
1556         nvsize = *(uint64_t *)db->db_data;
1557         dmu_buf_rele(db, FTAG);
1558 
1559         packed = kmem_alloc(nvsize, KM_SLEEP);
1560         error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
1561             DMU_READ_PREFETCH);
1562         if (error == 0)
1563                 error = nvlist_unpack(packed, nvsize, value, 0);
1564         kmem_free(packed, nvsize);
1565 
1566         return (error);
1567 }
1568 
1569 /*
1570  * Checks to see if the given vdev could not be opened, in which case we post a
1571  * sysevent to notify the autoreplace code that the device has been removed.
1572  */
1573 static void
1574 spa_check_removed(vdev_t *vd)
1575 {
1576         for (int c = 0; c < vd->vdev_children; c++)
1577                 spa_check_removed(vd->vdev_child[c]);
1578 
1579         if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd) &&
1580             !vd->vdev_ishole) {
1581                 zfs_post_autoreplace(vd->vdev_spa, vd);
1582                 spa_event_notify(vd->vdev_spa, vd, ESC_ZFS_VDEV_CHECK);
1583         }
1584 }
1585 
1586 /*
1587  * Validate the current config against the MOS config
1588  */
1589 static boolean_t
1590 spa_config_valid(spa_t *spa, nvlist_t *config)
1591 {
1592         vdev_t *mrvd, *rvd = spa->spa_root_vdev;
1593         nvlist_t *nv;
1594 
1595         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nv) == 0);
1596 
1597         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1598         VERIFY(spa_config_parse(spa, &mrvd, nv, NULL, 0, VDEV_ALLOC_LOAD) == 0);
1599 
1600         ASSERT3U(rvd->vdev_children, ==, mrvd->vdev_children);
1601 
1602         /*
1603          * If we're doing a normal import, then build up any additional
1604          * diagnostic information about missing devices in this config.
1605          * We'll pass this up to the user for further processing.
1606          */
1607         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG)) {
1608                 nvlist_t **child, *nv;
1609                 uint64_t idx = 0;
1610 
1611                 child = kmem_alloc(rvd->vdev_children * sizeof (nvlist_t **),
1612                     KM_SLEEP);
1613                 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1614 
1615                 for (int c = 0; c < rvd->vdev_children; c++) {
1616                         vdev_t *tvd = rvd->vdev_child[c];
1617                         vdev_t *mtvd  = mrvd->vdev_child[c];
1618 
1619                         if (tvd->vdev_ops == &vdev_missing_ops &&
1620                             mtvd->vdev_ops != &vdev_missing_ops &&
1621                             mtvd->vdev_islog)
1622                                 child[idx++] = vdev_config_generate(spa, mtvd,
1623                                     B_FALSE, 0);
1624                 }
1625 
1626                 if (idx) {
1627                         VERIFY(nvlist_add_nvlist_array(nv,
1628                             ZPOOL_CONFIG_CHILDREN, child, idx) == 0);
1629                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
1630                             ZPOOL_CONFIG_MISSING_DEVICES, nv) == 0);
1631 
1632                         for (int i = 0; i < idx; i++)
1633                                 nvlist_free(child[i]);
1634                 }
1635                 nvlist_free(nv);
1636                 kmem_free(child, rvd->vdev_children * sizeof (char **));
1637         }
1638 
1639         /*
1640          * Compare the root vdev tree with the information we have
1641          * from the MOS config (mrvd). Check each top-level vdev
1642          * with the corresponding MOS config top-level (mtvd).
1643          */
1644         for (int c = 0; c < rvd->vdev_children; c++) {
1645                 vdev_t *tvd = rvd->vdev_child[c];
1646                 vdev_t *mtvd  = mrvd->vdev_child[c];
1647 
1648                 /*
1649                  * Resolve any "missing" vdevs in the current configuration.
1650                  * If we find that the MOS config has more accurate information
1651                  * about the top-level vdev then use that vdev instead.
1652                  */
1653                 if (tvd->vdev_ops == &vdev_missing_ops &&
1654                     mtvd->vdev_ops != &vdev_missing_ops) {
1655 
1656                         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG))
1657                                 continue;
1658 
1659                         /*
1660                          * Device specific actions.
1661                          */
1662                         if (mtvd->vdev_islog) {
1663                                 spa_set_log_state(spa, SPA_LOG_CLEAR);
1664                         } else {
1665                                 /*
1666                                  * XXX - once we have 'readonly' pool
1667                                  * support we should be able to handle
1668                                  * missing data devices by transitioning
1669                                  * the pool to readonly.
1670                                  */
1671                                 continue;
1672                         }
1673 
1674                         /*
1675                          * Swap the missing vdev with the data we were
1676                          * able to obtain from the MOS config.
1677                          */
1678                         vdev_remove_child(rvd, tvd);
1679                         vdev_remove_child(mrvd, mtvd);
1680 
1681                         vdev_add_child(rvd, mtvd);
1682                         vdev_add_child(mrvd, tvd);
1683 
1684                         spa_config_exit(spa, SCL_ALL, FTAG);
1685                         vdev_load(mtvd);
1686                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1687 
1688                         vdev_reopen(rvd);
1689                 } else if (mtvd->vdev_islog) {
1690                         /*
1691                          * Load the slog device's state from the MOS config
1692                          * since it's possible that the label does not
1693                          * contain the most up-to-date information.
1694                          */
1695                         vdev_load_log_state(tvd, mtvd);
1696                         vdev_reopen(tvd);
1697                 }
1698         }
1699         vdev_free(mrvd);
1700         spa_config_exit(spa, SCL_ALL, FTAG);
1701 
1702         /*
1703          * Ensure we were able to validate the config.
1704          */
1705         return (rvd->vdev_guid_sum == spa->spa_uberblock.ub_guid_sum);
1706 }
1707 
1708 /*
1709  * Check for missing log devices
1710  */
1711 static boolean_t
1712 spa_check_logs(spa_t *spa)
1713 {
1714         boolean_t rv = B_FALSE;
1715         dsl_pool_t *dp = spa_get_dsl(spa);
1716 
1717         switch (spa->spa_log_state) {
1718         case SPA_LOG_MISSING:
1719                 /* need to recheck in case slog has been restored */
1720         case SPA_LOG_UNKNOWN:
1721                 rv = (dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
1722                     zil_check_log_chain, NULL, DS_FIND_CHILDREN) != 0);
1723                 if (rv)
1724                         spa_set_log_state(spa, SPA_LOG_MISSING);
1725                 break;
1726         }
1727         return (rv);
1728 }
1729 
1730 static boolean_t
1731 spa_passivate_log(spa_t *spa)
1732 {
1733         vdev_t *rvd = spa->spa_root_vdev;
1734         boolean_t slog_found = B_FALSE;
1735 
1736         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1737 
1738         if (!spa_has_slogs(spa))
1739                 return (B_FALSE);
1740 
1741         for (int c = 0; c < rvd->vdev_children; c++) {
1742                 vdev_t *tvd = rvd->vdev_child[c];
1743                 metaslab_group_t *mg = tvd->vdev_mg;
1744 
1745                 if (tvd->vdev_islog) {
1746                         metaslab_group_passivate(mg);
1747                         slog_found = B_TRUE;
1748                 }
1749         }
1750 
1751         return (slog_found);
1752 }
1753 
1754 static void
1755 spa_activate_log(spa_t *spa)
1756 {
1757         vdev_t *rvd = spa->spa_root_vdev;
1758 
1759         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1760 
1761         for (int c = 0; c < rvd->vdev_children; c++) {
1762                 vdev_t *tvd = rvd->vdev_child[c];
1763                 metaslab_group_t *mg = tvd->vdev_mg;
1764 
1765                 if (tvd->vdev_islog)
1766                         metaslab_group_activate(mg);
1767         }
1768 }
1769 
1770 int
1771 spa_offline_log(spa_t *spa)
1772 {
1773         int error;
1774 
1775         error = dmu_objset_find(spa_name(spa), zil_vdev_offline,
1776             NULL, DS_FIND_CHILDREN);
1777         if (error == 0) {
1778                 /*
1779                  * We successfully offlined the log device, sync out the
1780                  * current txg so that the "stubby" block can be removed
1781                  * by zil_sync().
1782                  */
1783                 txg_wait_synced(spa->spa_dsl_pool, 0);
1784         }
1785         return (error);
1786 }
1787 
1788 static void
1789 spa_aux_check_removed(spa_aux_vdev_t *sav)
1790 {
1791         for (int i = 0; i < sav->sav_count; i++)
1792                 spa_check_removed(sav->sav_vdevs[i]);
1793 }
1794 
1795 void
1796 spa_claim_notify(zio_t *zio)
1797 {
1798         spa_t *spa = zio->io_spa;
1799 
1800         if (zio->io_error)
1801                 return;
1802 
1803         mutex_enter(&spa->spa_props_lock);       /* any mutex will do */
1804         if (spa->spa_claim_max_txg < zio->io_bp->blk_birth)
1805                 spa->spa_claim_max_txg = zio->io_bp->blk_birth;
1806         mutex_exit(&spa->spa_props_lock);
1807 }
1808 
1809 typedef struct spa_load_error {
1810         uint64_t        sle_meta_count;
1811         uint64_t        sle_data_count;
1812 } spa_load_error_t;
1813 
1814 static void
1815 spa_load_verify_done(zio_t *zio)
1816 {
1817         blkptr_t *bp = zio->io_bp;
1818         spa_load_error_t *sle = zio->io_private;
1819         dmu_object_type_t type = BP_GET_TYPE(bp);
1820         int error = zio->io_error;
1821 
1822         if (error) {
1823                 if ((BP_GET_LEVEL(bp) != 0 || DMU_OT_IS_METADATA(type)) &&
1824                     type != DMU_OT_INTENT_LOG)
1825                         atomic_add_64(&sle->sle_meta_count, 1);
1826                 else
1827                         atomic_add_64(&sle->sle_data_count, 1);
1828         }
1829         zio_data_buf_free(zio->io_data, zio->io_size);
1830 }
1831 
1832 /*ARGSUSED*/
1833 static int
1834 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1835     const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1836 {
1837         if (!BP_IS_HOLE(bp) && !BP_IS_EMBEDDED(bp)) {
1838                 zio_t *rio = arg;
1839                 size_t size = BP_GET_PSIZE(bp);
1840                 void *data = zio_data_buf_alloc(size);
1841 
1842                 zio_nowait(zio_read(rio, spa, bp, data, size,
1843                     spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
1844                     ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
1845                     ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
1846         }
1847         return (0);
1848 }
1849 
1850 static int
1851 spa_load_verify(spa_t *spa)
1852 {
1853         zio_t *rio;
1854         spa_load_error_t sle = { 0 };
1855         zpool_rewind_policy_t policy;
1856         boolean_t verify_ok = B_FALSE;
1857         int error;
1858 
1859         zpool_get_rewind_policy(spa->spa_config, &policy);
1860 
1861         if (policy.zrp_request & ZPOOL_NEVER_REWIND)
1862                 return (0);
1863 
1864         rio = zio_root(spa, NULL, &sle,
1865             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1866 
1867         error = traverse_pool(spa, spa->spa_verify_min_txg,
1868             TRAVERSE_PRE | TRAVERSE_PREFETCH, spa_load_verify_cb, rio);
1869 
1870         (void) zio_wait(rio);
1871 
1872         spa->spa_load_meta_errors = sle.sle_meta_count;
1873         spa->spa_load_data_errors = sle.sle_data_count;
1874 
1875         if (!error && sle.sle_meta_count <= policy.zrp_maxmeta &&
1876             sle.sle_data_count <= policy.zrp_maxdata) {
1877                 int64_t loss = 0;
1878 
1879                 verify_ok = B_TRUE;
1880                 spa->spa_load_txg = spa->spa_uberblock.ub_txg;
1881                 spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
1882 
1883                 loss = spa->spa_last_ubsync_txg_ts - spa->spa_load_txg_ts;
1884                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1885                     ZPOOL_CONFIG_LOAD_TIME, spa->spa_load_txg_ts) == 0);
1886                 VERIFY(nvlist_add_int64(spa->spa_load_info,
1887                     ZPOOL_CONFIG_REWIND_TIME, loss) == 0);
1888                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1889                     ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count) == 0);
1890         } else {
1891                 spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
1892         }
1893 
1894         if (error) {
1895                 if (error != ENXIO && error != EIO)
1896                         error = SET_ERROR(EIO);
1897                 return (error);
1898         }
1899 
1900         return (verify_ok ? 0 : EIO);
1901 }
1902 
1903 /*
1904  * Find a value in the pool props object.
1905  */
1906 static void
1907 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
1908 {
1909         (void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
1910             zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
1911 }
1912 
1913 /*
1914  * Find a value in the pool directory object.
1915  */
1916 static int
1917 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val)
1918 {
1919         return (zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1920             name, sizeof (uint64_t), 1, val));
1921 }
1922 
1923 static int
1924 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
1925 {
1926         vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
1927         return (err);
1928 }
1929 
1930 /*
1931  * Fix up config after a partly-completed split.  This is done with the
1932  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
1933  * pool have that entry in their config, but only the splitting one contains
1934  * a list of all the guids of the vdevs that are being split off.
1935  *
1936  * This function determines what to do with that list: either rejoin
1937  * all the disks to the pool, or complete the splitting process.  To attempt
1938  * the rejoin, each disk that is offlined is marked online again, and
1939  * we do a reopen() call.  If the vdev label for every disk that was
1940  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
1941  * then we call vdev_split() on each disk, and complete the split.
1942  *
1943  * Otherwise we leave the config alone, with all the vdevs in place in
1944  * the original pool.
1945  */
1946 static void
1947 spa_try_repair(spa_t *spa, nvlist_t *config)
1948 {
1949         uint_t extracted;
1950         uint64_t *glist;
1951         uint_t i, gcount;
1952         nvlist_t *nvl;
1953         vdev_t **vd;
1954         boolean_t attempt_reopen;
1955 
1956         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
1957                 return;
1958 
1959         /* check that the config is complete */
1960         if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
1961             &glist, &gcount) != 0)
1962                 return;
1963 
1964         vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
1965 
1966         /* attempt to online all the vdevs & validate */
1967         attempt_reopen = B_TRUE;
1968         for (i = 0; i < gcount; i++) {
1969                 if (glist[i] == 0)      /* vdev is hole */
1970                         continue;
1971 
1972                 vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
1973                 if (vd[i] == NULL) {
1974                         /*
1975                          * Don't bother attempting to reopen the disks;
1976                          * just do the split.
1977                          */
1978                         attempt_reopen = B_FALSE;
1979                 } else {
1980                         /* attempt to re-online it */
1981                         vd[i]->vdev_offline = B_FALSE;
1982                 }
1983         }
1984 
1985         if (attempt_reopen) {
1986                 vdev_reopen(spa->spa_root_vdev);
1987 
1988                 /* check each device to see what state it's in */
1989                 for (extracted = 0, i = 0; i < gcount; i++) {
1990                         if (vd[i] != NULL &&
1991                             vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
1992                                 break;
1993                         ++extracted;
1994                 }
1995         }
1996 
1997         /*
1998          * If every disk has been moved to the new pool, or if we never
1999          * even attempted to look at them, then we split them off for
2000          * good.
2001          */
2002         if (!attempt_reopen || gcount == extracted) {
2003                 for (i = 0; i < gcount; i++)
2004                         if (vd[i] != NULL)
2005                                 vdev_split(vd[i]);
2006                 vdev_reopen(spa->spa_root_vdev);
2007         }
2008 
2009         kmem_free(vd, gcount * sizeof (vdev_t *));
2010 }
2011 
2012 static int
2013 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
2014     boolean_t mosconfig)
2015 {
2016         nvlist_t *config = spa->spa_config;
2017         char *ereport = FM_EREPORT_ZFS_POOL;
2018         char *comment;
2019         int error;
2020         uint64_t pool_guid;
2021         nvlist_t *nvl;
2022 
2023         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
2024                 return (SET_ERROR(EINVAL));
2025 
2026         ASSERT(spa->spa_comment == NULL);
2027         if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
2028                 spa->spa_comment = spa_strdup(comment);
2029 
2030         /*
2031          * Versioning wasn't explicitly added to the label until later, so if
2032          * it's not present treat it as the initial version.
2033          */
2034         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
2035             &spa->spa_ubsync.ub_version) != 0)
2036                 spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
2037 
2038         (void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
2039             &spa->spa_config_txg);
2040 
2041         if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
2042             spa_guid_exists(pool_guid, 0)) {
2043                 error = SET_ERROR(EEXIST);
2044         } else {
2045                 spa->spa_config_guid = pool_guid;
2046 
2047                 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT,
2048                     &nvl) == 0) {
2049                         VERIFY(nvlist_dup(nvl, &spa->spa_config_splitting,
2050                             KM_SLEEP) == 0);
2051                 }
2052 
2053                 nvlist_free(spa->spa_load_info);
2054                 spa->spa_load_info = fnvlist_alloc();
2055 
2056                 gethrestime(&spa->spa_loaded_ts);
2057                 error = spa_load_impl(spa, pool_guid, config, state, type,
2058                     mosconfig, &ereport);
2059         }
2060 
2061         spa->spa_minref = refcount_count(&spa->spa_refcount);
2062         if (error) {
2063                 if (error != EEXIST) {
2064                         spa->spa_loaded_ts.tv_sec = 0;
2065                         spa->spa_loaded_ts.tv_nsec = 0;
2066                 }
2067                 if (error != EBADF) {
2068                         zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
2069                 }
2070         }
2071         spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
2072         spa->spa_ena = 0;
2073 
2074         return (error);
2075 }
2076 
2077 /*
2078  * Load an existing storage pool, using the pool's builtin spa_config as a
2079  * source of configuration information.
2080  */
2081 static int
2082 spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config,
2083     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
2084     char **ereport)
2085 {
2086         int error = 0;
2087         nvlist_t *nvroot = NULL;
2088         nvlist_t *label;
2089         vdev_t *rvd;
2090         uberblock_t *ub = &spa->spa_uberblock;
2091         uint64_t children, config_cache_txg = spa->spa_config_txg;
2092         int orig_mode = spa->spa_mode;
2093         int parse;
2094         uint64_t obj;
2095         boolean_t missing_feat_write = B_FALSE;
2096         /*
2097          * If this is an untrusted config, access the pool in read-only mode.
2098          * This prevents things like resilvering recently removed devices.
2099          */
2100         if (!mosconfig)
2101                 spa->spa_mode = FREAD;
2102 
2103         ASSERT(MUTEX_HELD(&spa_namespace_lock));
2104 
2105         spa->spa_load_state = state;
2106 
2107         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot))
2108                 return (SET_ERROR(EINVAL));
2109 
2110         parse = (type == SPA_IMPORT_EXISTING ?
2111             VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
2112 
2113         /*
2114          * Create "The Godfather" zio to hold all async IOs
2115          */
2116         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
2117             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
2118 
2119         /*
2120          * Parse the configuration into a vdev tree.  We explicitly set the
2121          * value that will be returned by spa_version() since parsing the
2122          * configuration requires knowing the version number.
2123          */
2124         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2125         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, parse);
2126         spa_config_exit(spa, SCL_ALL, FTAG);
2127 
2128         if (error != 0)
2129                 return (error);
2130 
2131         ASSERT(spa->spa_root_vdev == rvd);
2132 
2133         if (type != SPA_IMPORT_ASSEMBLE) {
2134                 ASSERT(spa_guid(spa) == pool_guid);
2135         }
2136 
2137         /*
2138          * Try to open all vdevs, loading each label in the process.
2139          */
2140         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2141         error = vdev_open(rvd);
2142         spa_config_exit(spa, SCL_ALL, FTAG);
2143         if (error != 0)
2144                 return (error);
2145 
2146         /*
2147          * We need to validate the vdev labels against the configuration that
2148          * we have in hand, which is dependent on the setting of mosconfig. If
2149          * mosconfig is true then we're validating the vdev labels based on
2150          * that config.  Otherwise, we're validating against the cached config
2151          * (zpool.cache) that was read when we loaded the zfs module, and then
2152          * later we will recursively call spa_load() and validate against
2153          * the vdev config.
2154          *
2155          * If we're assembling a new pool that's been split off from an
2156          * existing pool, the labels haven't yet been updated so we skip
2157          * validation for now.
2158          */
2159         if (type != SPA_IMPORT_ASSEMBLE) {
2160                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2161                 error = vdev_validate(rvd, mosconfig);
2162                 spa_config_exit(spa, SCL_ALL, FTAG);
2163 
2164                 if (error != 0)
2165                         return (error);
2166 
2167                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2168                         return (SET_ERROR(ENXIO));
2169         }
2170 
2171         /*
2172          * Find the best uberblock.
2173          */
2174         vdev_uberblock_load(rvd, ub, &label);
2175 
2176         /*
2177          * If we weren't able to find a single valid uberblock, return failure.
2178          */
2179         if (ub->ub_txg == 0) {
2180                 nvlist_free(label);
2181                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
2182         }
2183 
2184         /*
2185          * If the pool has an unsupported version we can't open it.
2186          */
2187         if (!SPA_VERSION_IS_SUPPORTED(ub->ub_version)) {
2188                 nvlist_free(label);
2189                 return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
2190         }
2191 
2192         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2193                 nvlist_t *features;
2194 
2195                 /*
2196                  * If we weren't able to find what's necessary for reading the
2197                  * MOS in the label, return failure.
2198                  */
2199                 if (label == NULL || nvlist_lookup_nvlist(label,
2200                     ZPOOL_CONFIG_FEATURES_FOR_READ, &features) != 0) {
2201                         nvlist_free(label);
2202                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2203                             ENXIO));
2204                 }
2205 
2206                 /*
2207                  * Update our in-core representation with the definitive values
2208                  * from the label.
2209                  */
2210                 nvlist_free(spa->spa_label_features);
2211                 VERIFY(nvlist_dup(features, &spa->spa_label_features, 0) == 0);
2212         }
2213 
2214         nvlist_free(label);
2215 
2216         /*
2217          * Look through entries in the label nvlist's features_for_read. If
2218          * there is a feature listed there which we don't understand then we
2219          * cannot open a pool.
2220          */
2221         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2222                 nvlist_t *unsup_feat;
2223 
2224                 VERIFY(nvlist_alloc(&unsup_feat, NV_UNIQUE_NAME, KM_SLEEP) ==
2225                     0);
2226 
2227                 for (nvpair_t *nvp = nvlist_next_nvpair(spa->spa_label_features,
2228                     NULL); nvp != NULL;
2229                     nvp = nvlist_next_nvpair(spa->spa_label_features, nvp)) {
2230                         if (!zfeature_is_supported(nvpair_name(nvp))) {
2231                                 VERIFY(nvlist_add_string(unsup_feat,
2232                                     nvpair_name(nvp), "") == 0);
2233                         }
2234                 }
2235 
2236                 if (!nvlist_empty(unsup_feat)) {
2237                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
2238                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat) == 0);
2239                         nvlist_free(unsup_feat);
2240                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2241                             ENOTSUP));
2242                 }
2243 
2244                 nvlist_free(unsup_feat);
2245         }
2246 
2247         /*
2248          * If the vdev guid sum doesn't match the uberblock, we have an
2249          * incomplete configuration.  We first check to see if the pool
2250          * is aware of the complete config (i.e ZPOOL_CONFIG_VDEV_CHILDREN).
2251          * If it is, defer the vdev_guid_sum check till later so we
2252          * can handle missing vdevs.
2253          */
2254         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN,
2255             &children) != 0 && mosconfig && type != SPA_IMPORT_ASSEMBLE &&
2256             rvd->vdev_guid_sum != ub->ub_guid_sum)
2257                 return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
2258 
2259         if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
2260                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2261                 spa_try_repair(spa, config);
2262                 spa_config_exit(spa, SCL_ALL, FTAG);
2263                 nvlist_free(spa->spa_config_splitting);
2264                 spa->spa_config_splitting = NULL;
2265         }
2266 
2267         /*
2268          * Initialize internal SPA structures.
2269          */
2270         spa->spa_state = POOL_STATE_ACTIVE;
2271         spa->spa_ubsync = spa->spa_uberblock;
2272         spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
2273             TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
2274         spa->spa_first_txg = spa->spa_last_ubsync_txg ?
2275             spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
2276         spa->spa_claim_max_txg = spa->spa_first_txg;
2277         spa->spa_prev_software_version = ub->ub_software_version;
2278 
2279         error = dsl_pool_init(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
2280         if (error)
2281                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2282         spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
2283 
2284         if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object) != 0)
2285                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2286 
2287         if (spa_version(spa) >= SPA_VERSION_FEATURES) {
2288                 boolean_t missing_feat_read = B_FALSE;
2289                 nvlist_t *unsup_feat, *enabled_feat;
2290 
2291                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_READ,
2292                     &spa->spa_feat_for_read_obj) != 0) {
2293                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2294                 }
2295 
2296                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_WRITE,
2297                     &spa->spa_feat_for_write_obj) != 0) {
2298                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2299                 }
2300 
2301                 if (spa_dir_prop(spa, DMU_POOL_FEATURE_DESCRIPTIONS,
2302                     &spa->spa_feat_desc_obj) != 0) {
2303                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2304                 }
2305 
2306                 enabled_feat = fnvlist_alloc();
2307                 unsup_feat = fnvlist_alloc();
2308 
2309                 if (!spa_features_check(spa, B_FALSE,
2310                     unsup_feat, enabled_feat))
2311                         missing_feat_read = B_TRUE;
2312 
2313                 if (spa_writeable(spa) || state == SPA_LOAD_TRYIMPORT) {
2314                         if (!spa_features_check(spa, B_TRUE,
2315                             unsup_feat, enabled_feat)) {
2316                                 missing_feat_write = B_TRUE;
2317                         }
2318                 }
2319 
2320                 fnvlist_add_nvlist(spa->spa_load_info,
2321                     ZPOOL_CONFIG_ENABLED_FEAT, enabled_feat);
2322 
2323                 if (!nvlist_empty(unsup_feat)) {
2324                         fnvlist_add_nvlist(spa->spa_load_info,
2325                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
2326                 }
2327 
2328                 fnvlist_free(enabled_feat);
2329                 fnvlist_free(unsup_feat);
2330 
2331                 if (!missing_feat_read) {
2332                         fnvlist_add_boolean(spa->spa_load_info,
2333                             ZPOOL_CONFIG_CAN_RDONLY);
2334                 }
2335 
2336                 /*
2337                  * If the state is SPA_LOAD_TRYIMPORT, our objective is
2338                  * twofold: to determine whether the pool is available for
2339                  * import in read-write mode and (if it is not) whether the
2340                  * pool is available for import in read-only mode. If the pool
2341                  * is available for import in read-write mode, it is displayed
2342                  * as available in userland; if it is not available for import
2343                  * in read-only mode, it is displayed as unavailable in
2344                  * userland. If the pool is available for import in read-only
2345                  * mode but not read-write mode, it is displayed as unavailable
2346                  * in userland with a special note that the pool is actually
2347                  * available for open in read-only mode.
2348                  *
2349                  * As a result, if the state is SPA_LOAD_TRYIMPORT and we are
2350                  * missing a feature for write, we must first determine whether
2351                  * the pool can be opened read-only before returning to
2352                  * userland in order to know whether to display the
2353                  * abovementioned note.
2354                  */
2355                 if (missing_feat_read || (missing_feat_write &&
2356                     spa_writeable(spa))) {
2357                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2358                             ENOTSUP));
2359                 }
2360 
2361                 /*
2362                  * Load refcounts for ZFS features from disk into an in-memory
2363                  * cache during SPA initialization.
2364                  */
2365                 for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
2366                         uint64_t refcount;
2367 
2368                         error = feature_get_refcount_from_disk(spa,
2369                             &spa_feature_table[i], &refcount);
2370                         if (error == 0) {
2371                                 spa->spa_feat_refcount_cache[i] = refcount;
2372                         } else if (error == ENOTSUP) {
2373                                 spa->spa_feat_refcount_cache[i] =
2374                                     SPA_FEATURE_DISABLED;
2375                         } else {
2376                                 return (spa_vdev_err(rvd,
2377                                     VDEV_AUX_CORRUPT_DATA, EIO));
2378                         }
2379                 }
2380         }
2381 
2382         if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
2383                 if (spa_dir_prop(spa, DMU_POOL_FEATURE_ENABLED_TXG,
2384                     &spa->spa_feat_enabled_txg_obj) != 0)
2385                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2386         }
2387 
2388         spa->spa_is_initializing = B_TRUE;
2389         error = dsl_pool_open(spa->spa_dsl_pool);
2390         spa->spa_is_initializing = B_FALSE;
2391         if (error != 0)
2392                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2393 
2394         if (!mosconfig) {
2395                 uint64_t hostid;
2396                 nvlist_t *policy = NULL, *nvconfig;
2397 
2398                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2399                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2400 
2401                 if (!spa_is_root(spa) && nvlist_lookup_uint64(nvconfig,
2402                     ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
2403                         char *hostname;
2404                         unsigned long myhostid = 0;
2405 
2406                         VERIFY(nvlist_lookup_string(nvconfig,
2407                             ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
2408 
2409 #ifdef  _KERNEL
2410                         myhostid = zone_get_hostid(NULL);
2411 #else   /* _KERNEL */
2412                         /*
2413                          * We're emulating the system's hostid in userland, so
2414                          * we can't use zone_get_hostid().
2415                          */
2416                         (void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
2417 #endif  /* _KERNEL */
2418                         if (hostid != 0 && myhostid != 0 &&
2419                             hostid != myhostid) {
2420                                 nvlist_free(nvconfig);
2421                                 cmn_err(CE_WARN, "pool '%s' could not be "
2422                                     "loaded as it was last accessed by "
2423                                     "another system (host: %s hostid: 0x%lx). "
2424                                     "See: http://illumos.org/msg/ZFS-8000-EY",
2425                                     spa_name(spa), hostname,
2426                                     (unsigned long)hostid);
2427                                 return (SET_ERROR(EBADF));
2428                         }
2429                 }
2430                 if (nvlist_lookup_nvlist(spa->spa_config,
2431                     ZPOOL_REWIND_POLICY, &policy) == 0)
2432                         VERIFY(nvlist_add_nvlist(nvconfig,
2433                             ZPOOL_REWIND_POLICY, policy) == 0);
2434 
2435                 spa_config_set(spa, nvconfig);
2436                 spa_unload(spa);
2437                 spa_deactivate(spa);
2438                 spa_activate(spa, orig_mode);
2439 
2440                 return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
2441         }
2442 
2443         if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj) != 0)
2444                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2445         error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
2446         if (error != 0)
2447                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2448 
2449         /*
2450          * Load the bit that tells us to use the new accounting function
2451          * (raid-z deflation).  If we have an older pool, this will not
2452          * be present.
2453          */
2454         error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate);
2455         if (error != 0 && error != ENOENT)
2456                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2457 
2458         error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
2459             &spa->spa_creation_version);
2460         if (error != 0 && error != ENOENT)
2461                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2462 
2463         /*
2464          * Load the persistent error log.  If we have an older pool, this will
2465          * not be present.
2466          */
2467         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last);
2468         if (error != 0 && error != ENOENT)
2469                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2470 
2471         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
2472             &spa->spa_errlog_scrub);
2473         if (error != 0 && error != ENOENT)
2474                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2475 
2476         /*
2477          * Load the history object.  If we have an older pool, this
2478          * will not be present.
2479          */
2480         error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history);
2481         if (error != 0 && error != ENOENT)
2482                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2483 
2484         /*
2485          * If we're assembling the pool from the split-off vdevs of
2486          * an existing pool, we don't want to attach the spares & cache
2487          * devices.
2488          */
2489 
2490         /*
2491          * Load any hot spares for this pool.
2492          */
2493         error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object);
2494         if (error != 0 && error != ENOENT)
2495                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2496         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2497                 ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
2498                 if (load_nvlist(spa, spa->spa_spares.sav_object,
2499                     &spa->spa_spares.sav_config) != 0)
2500                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2501 
2502                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2503                 spa_load_spares(spa);
2504                 spa_config_exit(spa, SCL_ALL, FTAG);
2505         } else if (error == 0) {
2506                 spa->spa_spares.sav_sync = B_TRUE;
2507         }
2508 
2509         /*
2510          * Load any level 2 ARC devices for this pool.
2511          */
2512         error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
2513             &spa->spa_l2cache.sav_object);
2514         if (error != 0 && error != ENOENT)
2515                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2516         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2517                 ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
2518                 if (load_nvlist(spa, spa->spa_l2cache.sav_object,
2519                     &spa->spa_l2cache.sav_config) != 0)
2520                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2521 
2522                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2523                 spa_load_l2cache(spa);
2524                 spa_config_exit(spa, SCL_ALL, FTAG);
2525         } else if (error == 0) {
2526                 spa->spa_l2cache.sav_sync = B_TRUE;
2527         }
2528 
2529         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2530 
2531         error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object);
2532         if (error && error != ENOENT)
2533                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2534 
2535         if (error == 0) {
2536                 uint64_t autoreplace;
2537 
2538                 spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
2539                 spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
2540                 spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
2541                 spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
2542                 spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
2543                 spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
2544                     &spa->spa_dedup_ditto);
2545 
2546                 spa->spa_autoreplace = (autoreplace != 0);
2547         }
2548 
2549         /*
2550          * If the 'autoreplace' property is set, then post a resource notifying
2551          * the ZFS DE that it should not issue any faults for unopenable
2552          * devices.  We also iterate over the vdevs, and post a sysevent for any
2553          * unopenable vdevs so that the normal autoreplace handler can take
2554          * over.
2555          */
2556         if (spa->spa_autoreplace && state != SPA_LOAD_TRYIMPORT) {
2557                 spa_check_removed(spa->spa_root_vdev);
2558                 /*
2559                  * For the import case, this is done in spa_import(), because
2560                  * at this point we're using the spare definitions from
2561                  * the MOS config, not necessarily from the userland config.
2562                  */
2563                 if (state != SPA_LOAD_IMPORT) {
2564                         spa_aux_check_removed(&spa->spa_spares);
2565                         spa_aux_check_removed(&spa->spa_l2cache);
2566                 }
2567         }
2568 
2569         /*
2570          * Load the vdev state for all toplevel vdevs.
2571          */
2572         vdev_load(rvd);
2573 
2574         /*
2575          * Propagate the leaf DTLs we just loaded all the way up the tree.
2576          */
2577         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2578         vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
2579         spa_config_exit(spa, SCL_ALL, FTAG);
2580 
2581         /*
2582          * Load the DDTs (dedup tables).
2583          */
2584         error = ddt_load(spa);
2585         if (error != 0)
2586                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2587 
2588         spa_update_dspace(spa);
2589 
2590         /*
2591          * Validate the config, using the MOS config to fill in any
2592          * information which might be missing.  If we fail to validate
2593          * the config then declare the pool unfit for use. If we're
2594          * assembling a pool from a split, the log is not transferred
2595          * over.
2596          */
2597         if (type != SPA_IMPORT_ASSEMBLE) {
2598                 nvlist_t *nvconfig;
2599 
2600                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2601                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2602 
2603                 if (!spa_config_valid(spa, nvconfig)) {
2604                         nvlist_free(nvconfig);
2605                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
2606                             ENXIO));
2607                 }
2608                 nvlist_free(nvconfig);
2609 
2610                 /*
2611                  * Now that we've validated the config, check the state of the
2612                  * root vdev.  If it can't be opened, it indicates one or
2613                  * more toplevel vdevs are faulted.
2614                  */
2615                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2616                         return (SET_ERROR(ENXIO));
2617 
2618                 if (spa_check_logs(spa)) {
2619                         *ereport = FM_EREPORT_ZFS_LOG_REPLAY;
2620                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG, ENXIO));
2621                 }
2622         }
2623 
2624         if (missing_feat_write) {
2625                 ASSERT(state == SPA_LOAD_TRYIMPORT);
2626 
2627                 /*
2628                  * At this point, we know that we can open the pool in
2629                  * read-only mode but not read-write mode. We now have enough
2630                  * information and can return to userland.
2631                  */
2632                 return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT, ENOTSUP));
2633         }
2634 
2635         /*
2636          * We've successfully opened the pool, verify that we're ready
2637          * to start pushing transactions.
2638          */
2639         if (state != SPA_LOAD_TRYIMPORT) {
2640                 if (error = spa_load_verify(spa))
2641                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2642                             error));
2643         }
2644 
2645         if (spa_writeable(spa) && (state == SPA_LOAD_RECOVER ||
2646             spa->spa_load_max_txg == UINT64_MAX)) {
2647                 dmu_tx_t *tx;
2648                 int need_update = B_FALSE;
2649                 dsl_pool_t *dp = spa_get_dsl(spa);
2650 
2651                 ASSERT(state != SPA_LOAD_TRYIMPORT);
2652 
2653                 /*
2654                  * Claim log blocks that haven't been committed yet.
2655                  * This must all happen in a single txg.
2656                  * Note: spa_claim_max_txg is updated by spa_claim_notify(),
2657                  * invoked from zil_claim_log_block()'s i/o done callback.
2658                  * Price of rollback is that we abandon the log.
2659                  */
2660                 spa->spa_claiming = B_TRUE;
2661 
2662                 tx = dmu_tx_create_assigned(dp, spa_first_txg(spa));
2663                 (void) dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
2664                     zil_claim, tx, DS_FIND_CHILDREN);
2665                 dmu_tx_commit(tx);
2666 
2667                 spa->spa_claiming = B_FALSE;
2668 
2669                 spa_set_log_state(spa, SPA_LOG_GOOD);
2670                 spa->spa_sync_on = B_TRUE;
2671                 txg_sync_start(spa->spa_dsl_pool);
2672 
2673                 /*
2674                  * Wait for all claims to sync.  We sync up to the highest
2675                  * claimed log block birth time so that claimed log blocks
2676                  * don't appear to be from the future.  spa_claim_max_txg
2677                  * will have been set for us by either zil_check_log_chain()
2678                  * (invoked from spa_check_logs()) or zil_claim() above.
2679                  */
2680                 txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
2681 
2682                 /*
2683                  * If the config cache is stale, or we have uninitialized
2684                  * metaslabs (see spa_vdev_add()), then update the config.
2685                  *
2686                  * If this is a verbatim import, trust the current
2687                  * in-core spa_config and update the disk labels.
2688                  */
2689                 if (config_cache_txg != spa->spa_config_txg ||
2690                     state == SPA_LOAD_IMPORT ||
2691                     state == SPA_LOAD_RECOVER ||
2692                     (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
2693                         need_update = B_TRUE;
2694 
2695                 for (int c = 0; c < rvd->vdev_children; c++)
2696                         if (rvd->vdev_child[c]->vdev_ms_array == 0)
2697                                 need_update = B_TRUE;
2698 
2699                 /*
2700                  * Update the config cache asychronously in case we're the
2701                  * root pool, in which case the config cache isn't writable yet.
2702                  */
2703                 if (need_update)
2704                         spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2705 
2706                 /*
2707                  * Check all DTLs to see if anything needs resilvering.
2708                  */
2709                 if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
2710                     vdev_resilver_needed(rvd, NULL, NULL))
2711                         spa_async_request(spa, SPA_ASYNC_RESILVER);
2712 
2713                 /*
2714                  * Log the fact that we booted up (so that we can detect if
2715                  * we rebooted in the middle of an operation).
2716                  */
2717                 spa_history_log_version(spa, "open");
2718 
2719                 /*
2720                  * Delete any inconsistent datasets.
2721                  */
2722                 (void) dmu_objset_find(spa_name(spa),
2723                     dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
2724 
2725                 /*
2726                  * Clean up any stale temporary dataset userrefs.
2727                  */
2728                 dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
2729         }
2730 
2731         return (0);
2732 }
2733 
2734 static int
2735 spa_load_retry(spa_t *spa, spa_load_state_t state, int mosconfig)
2736 {
2737         int mode = spa->spa_mode;
2738 
2739         spa_unload(spa);
2740         spa_deactivate(spa);
2741 
2742         spa->spa_load_max_txg--;
2743 
2744         spa_activate(spa, mode);
2745         spa_async_suspend(spa);
2746 
2747         return (spa_load(spa, state, SPA_IMPORT_EXISTING, mosconfig));
2748 }
2749 
2750 /*
2751  * If spa_load() fails this function will try loading prior txg's. If
2752  * 'state' is SPA_LOAD_RECOVER and one of these loads succeeds the pool
2753  * will be rewound to that txg. If 'state' is not SPA_LOAD_RECOVER this
2754  * function will not rewind the pool and will return the same error as
2755  * spa_load().
2756  */
2757 static int
2758 spa_load_best(spa_t *spa, spa_load_state_t state, int mosconfig,
2759     uint64_t max_request, int rewind_flags)
2760 {
2761         nvlist_t *loadinfo = NULL;
2762         nvlist_t *config = NULL;
2763         int load_error, rewind_error;
2764         uint64_t safe_rewind_txg;
2765         uint64_t min_txg;
2766 
2767         if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
2768                 spa->spa_load_max_txg = spa->spa_load_txg;
2769                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2770         } else {
2771                 spa->spa_load_max_txg = max_request;
2772         }
2773 
2774         load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING,
2775             mosconfig);
2776         if (load_error == 0)
2777                 return (0);
2778 
2779         if (spa->spa_root_vdev != NULL)
2780                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2781 
2782         spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
2783         spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
2784 
2785         if (rewind_flags & ZPOOL_NEVER_REWIND) {
2786                 nvlist_free(config);
2787                 return (load_error);
2788         }
2789 
2790         if (state == SPA_LOAD_RECOVER) {
2791                 /* Price of rolling back is discarding txgs, including log */
2792                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2793         } else {
2794                 /*
2795                  * If we aren't rolling back save the load info from our first
2796                  * import attempt so that we can restore it after attempting
2797                  * to rewind.
2798                  */
2799                 loadinfo = spa->spa_load_info;
2800                 spa->spa_load_info = fnvlist_alloc();
2801         }
2802 
2803         spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
2804         safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
2805         min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
2806             TXG_INITIAL : safe_rewind_txg;
2807 
2808         /*
2809          * Continue as long as we're finding errors, we're still within
2810          * the acceptable rewind range, and we're still finding uberblocks
2811          */
2812         while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
2813             spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
2814                 if (spa->spa_load_max_txg < safe_rewind_txg)
2815                         spa->spa_extreme_rewind = B_TRUE;
2816                 rewind_error = spa_load_retry(spa, state, mosconfig);
2817         }
2818 
2819         spa->spa_extreme_rewind = B_FALSE;
2820         spa->spa_load_max_txg = UINT64_MAX;
2821 
2822         if (config && (rewind_error || state != SPA_LOAD_RECOVER))
2823                 spa_config_set(spa, config);
2824 
2825         if (state == SPA_LOAD_RECOVER) {
2826                 ASSERT3P(loadinfo, ==, NULL);
2827                 return (rewind_error);
2828         } else {
2829                 /* Store the rewind info as part of the initial load info */
2830                 fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
2831                     spa->spa_load_info);
2832 
2833                 /* Restore the initial load info */
2834                 fnvlist_free(spa->spa_load_info);
2835                 spa->spa_load_info = loadinfo;
2836 
2837                 return (load_error);
2838         }
2839 }
2840 
2841 /*
2842  * Pool Open/Import
2843  *
2844  * The import case is identical to an open except that the configuration is sent
2845  * down from userland, instead of grabbed from the configuration cache.  For the
2846  * case of an open, the pool configuration will exist in the
2847  * POOL_STATE_UNINITIALIZED state.
2848  *
2849  * The stats information (gen/count/ustats) is used to gather vdev statistics at
2850  * the same time open the pool, without having to keep around the spa_t in some
2851  * ambiguous state.
2852  */
2853 static int
2854 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
2855     nvlist_t **config)
2856 {
2857         spa_t *spa;
2858         spa_load_state_t state = SPA_LOAD_OPEN;
2859         int error;
2860         int locked = B_FALSE;
2861 
2862         *spapp = NULL;
2863 
2864         /*
2865          * As disgusting as this is, we need to support recursive calls to this
2866          * function because dsl_dir_open() is called during spa_load(), and ends
2867          * up calling spa_open() again.  The real fix is to figure out how to
2868          * avoid dsl_dir_open() calling this in the first place.
2869          */
2870         if (mutex_owner(&spa_namespace_lock) != curthread) {
2871                 mutex_enter(&spa_namespace_lock);
2872                 locked = B_TRUE;
2873         }
2874 
2875         if ((spa = spa_lookup(pool)) == NULL) {
2876                 if (locked)
2877                         mutex_exit(&spa_namespace_lock);
2878                 return (SET_ERROR(ENOENT));
2879         }
2880 
2881         if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
2882                 zpool_rewind_policy_t policy;
2883 
2884                 zpool_get_rewind_policy(nvpolicy ? nvpolicy : spa->spa_config,
2885                     &policy);
2886                 if (policy.zrp_request & ZPOOL_DO_REWIND)
2887                         state = SPA_LOAD_RECOVER;
2888 
2889                 spa_activate(spa, spa_mode_global);
2890 
2891                 if (state != SPA_LOAD_RECOVER)
2892                         spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
2893 
2894                 error = spa_load_best(spa, state, B_FALSE, policy.zrp_txg,
2895                     policy.zrp_request);
2896 
2897                 if (error == EBADF) {
2898                         /*
2899                          * If vdev_validate() returns failure (indicated by
2900                          * EBADF), it indicates that one of the vdevs indicates
2901                          * that the pool has been exported or destroyed.  If
2902                          * this is the case, the config cache is out of sync and
2903                          * we should remove the pool from the namespace.
2904                          */
2905                         spa_unload(spa);
2906                         spa_deactivate(spa);
2907                         spa_config_sync(spa, B_TRUE, B_TRUE);
2908                         spa_remove(spa);
2909                         if (locked)
2910                                 mutex_exit(&spa_namespace_lock);
2911                         return (SET_ERROR(ENOENT));
2912                 }
2913 
2914                 if (error) {
2915                         /*
2916                          * We can't open the pool, but we still have useful
2917                          * information: the state of each vdev after the
2918                          * attempted vdev_open().  Return this to the user.
2919                          */
2920                         if (config != NULL && spa->spa_config) {
2921                                 VERIFY(nvlist_dup(spa->spa_config, config,
2922                                     KM_SLEEP) == 0);
2923                                 VERIFY(nvlist_add_nvlist(*config,
2924                                     ZPOOL_CONFIG_LOAD_INFO,
2925                                     spa->spa_load_info) == 0);
2926                         }
2927                         spa_unload(spa);
2928                         spa_deactivate(spa);
2929                         spa->spa_last_open_failed = error;
2930                         if (locked)
2931                                 mutex_exit(&spa_namespace_lock);
2932                         *spapp = NULL;
2933                         return (error);
2934                 }
2935         }
2936 
2937         spa_open_ref(spa, tag);
2938 
2939         if (config != NULL)
2940                 *config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2941 
2942         /*
2943          * If we've recovered the pool, pass back any information we
2944          * gathered while doing the load.
2945          */
2946         if (state == SPA_LOAD_RECOVER) {
2947                 VERIFY(nvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
2948                     spa->spa_load_info) == 0);
2949         }
2950 
2951         if (locked) {
2952                 spa->spa_last_open_failed = 0;
2953                 spa->spa_last_ubsync_txg = 0;
2954                 spa->spa_load_txg = 0;
2955                 mutex_exit(&spa_namespace_lock);
2956         }
2957 
2958         *spapp = spa;
2959 
2960         return (0);
2961 }
2962 
2963 int
2964 spa_open_rewind(const char *name, spa_t **spapp, void *tag, nvlist_t *policy,
2965     nvlist_t **config)
2966 {
2967         return (spa_open_common(name, spapp, tag, policy, config));
2968 }
2969 
2970 int
2971 spa_open(const char *name, spa_t **spapp, void *tag)
2972 {
2973         return (spa_open_common(name, spapp, tag, NULL, NULL));
2974 }
2975 
2976 /*
2977  * Lookup the given spa_t, incrementing the inject count in the process,
2978  * preventing it from being exported or destroyed.
2979  */
2980 spa_t *
2981 spa_inject_addref(char *name)
2982 {
2983         spa_t *spa;
2984 
2985         mutex_enter(&spa_namespace_lock);
2986         if ((spa = spa_lookup(name)) == NULL) {
2987                 mutex_exit(&spa_namespace_lock);
2988                 return (NULL);
2989         }
2990         spa->spa_inject_ref++;
2991         mutex_exit(&spa_namespace_lock);
2992 
2993         return (spa);
2994 }
2995 
2996 void
2997 spa_inject_delref(spa_t *spa)
2998 {
2999         mutex_enter(&spa_namespace_lock);
3000         spa->spa_inject_ref--;
3001         mutex_exit(&spa_namespace_lock);
3002 }
3003 
3004 /*
3005  * Add spares device information to the nvlist.
3006  */
3007 static void
3008 spa_add_spares(spa_t *spa, nvlist_t *config)
3009 {
3010         nvlist_t **spares;
3011         uint_t i, nspares;
3012         nvlist_t *nvroot;
3013         uint64_t guid;
3014         vdev_stat_t *vs;
3015         uint_t vsc;
3016         uint64_t pool;
3017 
3018         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3019 
3020         if (spa->spa_spares.sav_count == 0)
3021                 return;
3022 
3023         VERIFY(nvlist_lookup_nvlist(config,
3024             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3025         VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
3026             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
3027         if (nspares != 0) {
3028                 VERIFY(nvlist_add_nvlist_array(nvroot,
3029                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3030                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
3031                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
3032 
3033                 /*
3034                  * Go through and find any spares which have since been
3035                  * repurposed as an active spare.  If this is the case, update
3036                  * their status appropriately.
3037                  */
3038                 for (i = 0; i < nspares; i++) {
3039                         VERIFY(nvlist_lookup_uint64(spares[i],
3040                             ZPOOL_CONFIG_GUID, &guid) == 0);
3041                         if (spa_spare_exists(guid, &pool, NULL) &&
3042                             pool != 0ULL) {
3043                                 VERIFY(nvlist_lookup_uint64_array(
3044                                     spares[i], ZPOOL_CONFIG_VDEV_STATS,
3045                                     (uint64_t **)&vs, &vsc) == 0);
3046                                 vs->vs_state = VDEV_STATE_CANT_OPEN;
3047                                 vs->vs_aux = VDEV_AUX_SPARED;
3048                         }
3049                 }
3050         }
3051 }
3052 
3053 /*
3054  * Add l2cache device information to the nvlist, including vdev stats.
3055  */
3056 static void
3057 spa_add_l2cache(spa_t *spa, nvlist_t *config)
3058 {
3059         nvlist_t **l2cache;
3060         uint_t i, j, nl2cache;
3061         nvlist_t *nvroot;
3062         uint64_t guid;
3063         vdev_t *vd;
3064         vdev_stat_t *vs;
3065         uint_t vsc;
3066 
3067         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3068 
3069         if (spa->spa_l2cache.sav_count == 0)
3070                 return;
3071 
3072         VERIFY(nvlist_lookup_nvlist(config,
3073             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3074         VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
3075             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3076         if (nl2cache != 0) {
3077                 VERIFY(nvlist_add_nvlist_array(nvroot,
3078                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3079                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
3080                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3081 
3082                 /*
3083                  * Update level 2 cache device stats.
3084                  */
3085 
3086                 for (i = 0; i < nl2cache; i++) {
3087                         VERIFY(nvlist_lookup_uint64(l2cache[i],
3088                             ZPOOL_CONFIG_GUID, &guid) == 0);
3089 
3090                         vd = NULL;
3091                         for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
3092                                 if (guid ==
3093                                     spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
3094                                         vd = spa->spa_l2cache.sav_vdevs[j];
3095                                         break;
3096                                 }
3097                         }
3098                         ASSERT(vd != NULL);
3099 
3100                         VERIFY(nvlist_lookup_uint64_array(l2cache[i],
3101                             ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc)
3102                             == 0);
3103                         vdev_get_stats(vd, vs);
3104                 }
3105         }
3106 }
3107 
3108 static void
3109 spa_add_feature_stats(spa_t *spa, nvlist_t *config)
3110 {
3111         nvlist_t *features;
3112         zap_cursor_t zc;
3113         zap_attribute_t za;
3114 
3115         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3116         VERIFY(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3117 
3118         if (spa->spa_feat_for_read_obj != 0) {
3119                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3120                     spa->spa_feat_for_read_obj);
3121                     zap_cursor_retrieve(&zc, &za) == 0;
3122                     zap_cursor_advance(&zc)) {
3123                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3124                             za.za_num_integers == 1);
3125                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3126                             za.za_first_integer));
3127                 }
3128                 zap_cursor_fini(&zc);
3129         }
3130 
3131         if (spa->spa_feat_for_write_obj != 0) {
3132                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3133                     spa->spa_feat_for_write_obj);
3134                     zap_cursor_retrieve(&zc, &za) == 0;
3135                     zap_cursor_advance(&zc)) {
3136                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3137                             za.za_num_integers == 1);
3138                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3139                             za.za_first_integer));
3140                 }
3141                 zap_cursor_fini(&zc);
3142         }
3143 
3144         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
3145             features) == 0);
3146         nvlist_free(features);
3147 }
3148 
3149 int
3150 spa_get_stats(const char *name, nvlist_t **config,
3151     char *altroot, size_t buflen)
3152 {
3153         int error;
3154         spa_t *spa;
3155 
3156         *config = NULL;
3157         error = spa_open_common(name, &spa, FTAG, NULL, config);
3158 
3159         if (spa != NULL) {
3160                 /*
3161                  * This still leaves a window of inconsistency where the spares
3162                  * or l2cache devices could change and the config would be
3163                  * self-inconsistent.
3164                  */
3165                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3166 
3167                 if (*config != NULL) {
3168                         uint64_t loadtimes[2];
3169 
3170                         loadtimes[0] = spa->spa_loaded_ts.tv_sec;
3171                         loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
3172                         VERIFY(nvlist_add_uint64_array(*config,
3173                             ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2) == 0);
3174 
3175                         VERIFY(nvlist_add_uint64(*config,
3176                             ZPOOL_CONFIG_ERRCOUNT,
3177                             spa_get_errlog_size(spa)) == 0);
3178 
3179                         if (spa_suspended(spa))
3180                                 VERIFY(nvlist_add_uint64(*config,
3181                                     ZPOOL_CONFIG_SUSPENDED,
3182                                     spa->spa_failmode) == 0);
3183 
3184                         spa_add_spares(spa, *config);
3185                         spa_add_l2cache(spa, *config);
3186                         spa_add_feature_stats(spa, *config);
3187                 }
3188         }
3189 
3190         /*
3191          * We want to get the alternate root even for faulted pools, so we cheat
3192          * and call spa_lookup() directly.
3193          */
3194         if (altroot) {
3195                 if (spa == NULL) {
3196                         mutex_enter(&spa_namespace_lock);
3197                         spa = spa_lookup(name);
3198                         if (spa)
3199                                 spa_altroot(spa, altroot, buflen);
3200                         else
3201                                 altroot[0] = '\0';
3202                         spa = NULL;
3203                         mutex_exit(&spa_namespace_lock);
3204                 } else {
3205                         spa_altroot(spa, altroot, buflen);
3206                 }
3207         }
3208 
3209         if (spa != NULL) {
3210                 spa_config_exit(spa, SCL_CONFIG, FTAG);
3211                 spa_close(spa, FTAG);
3212         }
3213 
3214         return (error);
3215 }
3216 
3217 /*
3218  * Validate that the auxiliary device array is well formed.  We must have an
3219  * array of nvlists, each which describes a valid leaf vdev.  If this is an
3220  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
3221  * specified, as long as they are well-formed.
3222  */
3223 static int
3224 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
3225     spa_aux_vdev_t *sav, const char *config, uint64_t version,
3226     vdev_labeltype_t label)
3227 {
3228         nvlist_t **dev;
3229         uint_t i, ndev;
3230         vdev_t *vd;
3231         int error;
3232 
3233         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3234 
3235         /*
3236          * It's acceptable to have no devs specified.
3237          */
3238         if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
3239                 return (0);
3240 
3241         if (ndev == 0)
3242                 return (SET_ERROR(EINVAL));
3243 
3244         /*
3245          * Make sure the pool is formatted with a version that supports this
3246          * device type.
3247          */
3248         if (spa_version(spa) < version)
3249                 return (SET_ERROR(ENOTSUP));
3250 
3251         /*
3252          * Set the pending device list so we correctly handle device in-use
3253          * checking.
3254          */
3255         sav->sav_pending = dev;
3256         sav->sav_npending = ndev;
3257 
3258         for (i = 0; i < ndev; i++) {
3259                 if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
3260                     mode)) != 0)
3261                         goto out;
3262 
3263                 if (!vd->vdev_ops->vdev_op_leaf) {
3264                         vdev_free(vd);
3265                         error = SET_ERROR(EINVAL);
3266                         goto out;
3267                 }
3268 
3269                 /*
3270                  * The L2ARC currently only supports disk devices in
3271                  * kernel context.  For user-level testing, we allow it.
3272                  */
3273 #ifdef _KERNEL
3274                 if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
3275                     strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
3276                         error = SET_ERROR(ENOTBLK);
3277                         vdev_free(vd);
3278                         goto out;
3279                 }
3280 #endif
3281                 vd->vdev_top = vd;
3282 
3283                 if ((error = vdev_open(vd)) == 0 &&
3284                     (error = vdev_label_init(vd, crtxg, label)) == 0) {
3285                         VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
3286                             vd->vdev_guid) == 0);
3287                 }
3288 
3289                 vdev_free(vd);
3290 
3291                 if (error &&
3292                     (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
3293                         goto out;
3294                 else
3295                         error = 0;
3296         }
3297 
3298 out:
3299         sav->sav_pending = NULL;
3300         sav->sav_npending = 0;
3301         return (error);
3302 }
3303 
3304 static int
3305 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
3306 {
3307         int error;
3308 
3309         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3310 
3311         if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3312             &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
3313             VDEV_LABEL_SPARE)) != 0) {
3314                 return (error);
3315         }
3316 
3317         return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3318             &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
3319             VDEV_LABEL_L2CACHE));
3320 }
3321 
3322 static void
3323 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
3324     const char *config)
3325 {
3326         int i;
3327 
3328         if (sav->sav_config != NULL) {
3329                 nvlist_t **olddevs;
3330                 uint_t oldndevs;
3331                 nvlist_t **newdevs;
3332 
3333                 /*
3334                  * Generate new dev list by concatentating with the
3335                  * current dev list.
3336                  */
3337                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
3338                     &olddevs, &oldndevs) == 0);
3339 
3340                 newdevs = kmem_alloc(sizeof (void *) *
3341                     (ndevs + oldndevs), KM_SLEEP);
3342                 for (i = 0; i < oldndevs; i++)
3343                         VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
3344                             KM_SLEEP) == 0);
3345                 for (i = 0; i < ndevs; i++)
3346                         VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
3347                             KM_SLEEP) == 0);
3348 
3349                 VERIFY(nvlist_remove(sav->sav_config, config,
3350                     DATA_TYPE_NVLIST_ARRAY) == 0);
3351 
3352                 VERIFY(nvlist_add_nvlist_array(sav->sav_config,
3353                     config, newdevs, ndevs + oldndevs) == 0);
3354                 for (i = 0; i < oldndevs + ndevs; i++)
3355                         nvlist_free(newdevs[i]);
3356                 kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
3357         } else {
3358                 /*
3359                  * Generate a new dev list.
3360                  */
3361                 VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
3362                     KM_SLEEP) == 0);
3363                 VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
3364                     devs, ndevs) == 0);
3365         }
3366 }
3367 
3368 /*
3369  * Stop and drop level 2 ARC devices
3370  */
3371 void
3372 spa_l2cache_drop(spa_t *spa)
3373 {
3374         vdev_t *vd;
3375         int i;
3376         spa_aux_vdev_t *sav = &spa->spa_l2cache;
3377 
3378         for (i = 0; i < sav->sav_count; i++) {
3379                 uint64_t pool;
3380 
3381                 vd = sav->sav_vdevs[i];
3382                 ASSERT(vd != NULL);
3383 
3384                 if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
3385                     pool != 0ULL && l2arc_vdev_present(vd))
3386                         l2arc_remove_vdev(vd);
3387         }
3388 }
3389 
3390 /*
3391  * Pool Creation
3392  */
3393 int
3394 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
3395     nvlist_t *zplprops)
3396 {
3397         spa_t *spa;
3398         char *altroot = NULL;
3399         vdev_t *rvd;
3400         dsl_pool_t *dp;
3401         dmu_tx_t *tx;
3402         int error = 0;
3403         uint64_t txg = TXG_INITIAL;
3404         nvlist_t **spares, **l2cache;
3405         uint_t nspares, nl2cache;
3406         uint64_t version, obj;
3407         boolean_t has_features;
3408 
3409         /*
3410          * If this pool already exists, return failure.
3411          */
3412         mutex_enter(&spa_namespace_lock);
3413         if (spa_lookup(pool) != NULL) {
3414                 mutex_exit(&spa_namespace_lock);
3415                 return (SET_ERROR(EEXIST));
3416         }
3417 
3418         /*
3419          * Allocate a new spa_t structure.
3420          */
3421         (void) nvlist_lookup_string(props,
3422             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3423         spa = spa_add(pool, NULL, altroot);
3424         spa_activate(spa, spa_mode_global);
3425 
3426         if (props && (error = spa_prop_validate(spa, props))) {
3427                 spa_deactivate(spa);
3428                 spa_remove(spa);
3429                 mutex_exit(&spa_namespace_lock);
3430                 return (error);
3431         }
3432 
3433         has_features = B_FALSE;
3434         for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
3435             elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
3436                 if (zpool_prop_feature(nvpair_name(elem)))
3437                         has_features = B_TRUE;
3438         }
3439 
3440         if (has_features || nvlist_lookup_uint64(props,
3441             zpool_prop_to_name(ZPOOL_PROP_VERSION), &version) != 0) {
3442                 version = SPA_VERSION;
3443         }
3444         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
3445 
3446         spa->spa_first_txg = txg;
3447         spa->spa_uberblock.ub_txg = txg - 1;
3448         spa->spa_uberblock.ub_version = version;
3449         spa->spa_ubsync = spa->spa_uberblock;
3450 
3451         /*
3452          * Create "The Godfather" zio to hold all async IOs
3453          */
3454         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
3455             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
3456 
3457         /*
3458          * Create the root vdev.
3459          */
3460         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3461 
3462         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
3463 
3464         ASSERT(error != 0 || rvd != NULL);
3465         ASSERT(error != 0 || spa->spa_root_vdev == rvd);
3466 
3467         if (error == 0 && !zfs_allocatable_devs(nvroot))
3468                 error = SET_ERROR(EINVAL);
3469 
3470         if (error == 0 &&
3471             (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
3472             (error = spa_validate_aux(spa, nvroot, txg,
3473             VDEV_ALLOC_ADD)) == 0) {
3474                 for (int c = 0; c < rvd->vdev_children; c++) {
3475                         vdev_metaslab_set_size(rvd->vdev_child[c]);
3476                         vdev_expand(rvd->vdev_child[c], txg);
3477                 }
3478         }
3479 
3480         spa_config_exit(spa, SCL_ALL, FTAG);
3481 
3482         if (error != 0) {
3483                 spa_unload(spa);
3484                 spa_deactivate(spa);
3485                 spa_remove(spa);
3486                 mutex_exit(&spa_namespace_lock);
3487                 return (error);
3488         }
3489 
3490         /*
3491          * Get the list of spares, if specified.
3492          */
3493         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3494             &spares, &nspares) == 0) {
3495                 VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
3496                     KM_SLEEP) == 0);
3497                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3498                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3499                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3500                 spa_load_spares(spa);
3501                 spa_config_exit(spa, SCL_ALL, FTAG);
3502                 spa->spa_spares.sav_sync = B_TRUE;
3503         }
3504 
3505         /*
3506          * Get the list of level 2 cache devices, if specified.
3507          */
3508         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3509             &l2cache, &nl2cache) == 0) {
3510                 VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3511                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
3512                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3513                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3514                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3515                 spa_load_l2cache(spa);
3516                 spa_config_exit(spa, SCL_ALL, FTAG);
3517                 spa->spa_l2cache.sav_sync = B_TRUE;
3518         }
3519 
3520         spa->spa_is_initializing = B_TRUE;
3521         spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
3522         spa->spa_meta_objset = dp->dp_meta_objset;
3523         spa->spa_is_initializing = B_FALSE;
3524 
3525         /*
3526          * Create DDTs (dedup tables).
3527          */
3528         ddt_create(spa);
3529 
3530         spa_update_dspace(spa);
3531 
3532         tx = dmu_tx_create_assigned(dp, txg);
3533 
3534         /*
3535          * Create the pool config object.
3536          */
3537         spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
3538             DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
3539             DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
3540 
3541         if (zap_add(spa->spa_meta_objset,
3542             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
3543             sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
3544                 cmn_err(CE_PANIC, "failed to add pool config");
3545         }
3546 
3547         if (spa_version(spa) >= SPA_VERSION_FEATURES)
3548                 spa_feature_create_zap_objects(spa, tx);
3549 
3550         if (zap_add(spa->spa_meta_objset,
3551             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
3552             sizeof (uint64_t), 1, &version, tx) != 0) {
3553                 cmn_err(CE_PANIC, "failed to add pool version");
3554         }
3555 
3556         /* Newly created pools with the right version are always deflated. */
3557         if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
3558                 spa->spa_deflate = TRUE;
3559                 if (zap_add(spa->spa_meta_objset,
3560                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
3561                     sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
3562                         cmn_err(CE_PANIC, "failed to add deflate");
3563                 }
3564         }
3565 
3566         /*
3567          * Create the deferred-free bpobj.  Turn off compression
3568          * because sync-to-convergence takes longer if the blocksize
3569          * keeps changing.
3570          */
3571         obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
3572         dmu_object_set_compress(spa->spa_meta_objset, obj,
3573             ZIO_COMPRESS_OFF, tx);
3574         if (zap_add(spa->spa_meta_objset,
3575             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
3576             sizeof (uint64_t), 1, &obj, tx) != 0) {
3577                 cmn_err(CE_PANIC, "failed to add bpobj");
3578         }
3579         VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
3580             spa->spa_meta_objset, obj));
3581 
3582         /*
3583          * Create the pool's history object.
3584          */
3585         if (version >= SPA_VERSION_ZPOOL_HISTORY)
3586                 spa_history_create_obj(spa, tx);
3587 
3588         /*
3589          * Set pool properties.
3590          */
3591         spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
3592         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
3593         spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
3594         spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
3595 
3596         if (props != NULL) {
3597                 spa_configfile_set(spa, props, B_FALSE);
3598                 spa_sync_props(props, tx);
3599         }
3600 
3601         dmu_tx_commit(tx);
3602 
3603         spa->spa_sync_on = B_TRUE;
3604         txg_sync_start(spa->spa_dsl_pool);
3605 
3606         /*
3607          * We explicitly wait for the first transaction to complete so that our
3608          * bean counters are appropriately updated.
3609          */
3610         txg_wait_synced(spa->spa_dsl_pool, txg);
3611 
3612         spa_config_sync(spa, B_FALSE, B_TRUE);
3613 
3614         spa_history_log_version(spa, "create");
3615 
3616         spa->spa_minref = refcount_count(&spa->spa_refcount);
3617 
3618         mutex_exit(&spa_namespace_lock);
3619 
3620         return (0);
3621 }
3622 
3623 #ifdef _KERNEL
3624 /*
3625  * Get the root pool information from the root disk, then import the root pool
3626  * during the system boot up time.
3627  */
3628 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
3629 
3630 static nvlist_t *
3631 spa_generate_rootconf(char *devpath, char *devid, uint64_t *guid)
3632 {
3633         nvlist_t *config;
3634         nvlist_t *nvtop, *nvroot;
3635         uint64_t pgid;
3636 
3637         if (vdev_disk_read_rootlabel(devpath, devid, &config) != 0)
3638                 return (NULL);
3639 
3640         /*
3641          * Add this top-level vdev to the child array.
3642          */
3643         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3644             &nvtop) == 0);
3645         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
3646             &pgid) == 0);
3647         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, guid) == 0);
3648 
3649         /*
3650          * Put this pool's top-level vdevs into a root vdev.
3651          */
3652         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3653         VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
3654             VDEV_TYPE_ROOT) == 0);
3655         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
3656         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
3657         VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
3658             &nvtop, 1) == 0);
3659 
3660         /*
3661          * Replace the existing vdev_tree with the new root vdev in
3662          * this pool's configuration (remove the old, add the new).
3663          */
3664         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
3665         nvlist_free(nvroot);
3666         return (config);
3667 }
3668 
3669 /*
3670  * Walk the vdev tree and see if we can find a device with "better"
3671  * configuration. A configuration is "better" if the label on that
3672  * device has a more recent txg.
3673  */
3674 static void
3675 spa_alt_rootvdev(vdev_t *vd, vdev_t **avd, uint64_t *txg)
3676 {
3677         for (int c = 0; c < vd->vdev_children; c++)
3678                 spa_alt_rootvdev(vd->vdev_child[c], avd, txg);
3679 
3680         if (vd->vdev_ops->vdev_op_leaf) {
3681                 nvlist_t *label;
3682                 uint64_t label_txg;
3683 
3684                 if (vdev_disk_read_rootlabel(vd->vdev_physpath, vd->vdev_devid,
3685                     &label) != 0)
3686                         return;
3687 
3688                 VERIFY(nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
3689                     &label_txg) == 0);
3690 
3691                 /*
3692                  * Do we have a better boot device?
3693                  */
3694                 if (label_txg > *txg) {
3695                         *txg = label_txg;
3696                         *avd = vd;
3697                 }
3698                 nvlist_free(label);
3699         }
3700 }
3701 
3702 /*
3703  * Import a root pool.
3704  *
3705  * For x86. devpath_list will consist of devid and/or physpath name of
3706  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
3707  * The GRUB "findroot" command will return the vdev we should boot.
3708  *
3709  * For Sparc, devpath_list consists the physpath name of the booting device
3710  * no matter the rootpool is a single device pool or a mirrored pool.
3711  * e.g.
3712  *      "/pci@1f,0/ide@d/disk@0,0:a"
3713  */
3714 int
3715 spa_import_rootpool(char *devpath, char *devid)
3716 {
3717         spa_t *spa;
3718         vdev_t *rvd, *bvd, *avd = NULL;
3719         nvlist_t *config, *nvtop;
3720         uint64_t guid, txg;
3721         char *pname;
3722         int error;
3723 
3724         /*
3725          * Read the label from the boot device and generate a configuration.
3726          */
3727         config = spa_generate_rootconf(devpath, devid, &guid);
3728 #if defined(_OBP) && defined(_KERNEL)
3729         if (config == NULL) {
3730                 if (strstr(devpath, "/iscsi/ssd") != NULL) {
3731                         /* iscsi boot */
3732                         get_iscsi_bootpath_phy(devpath);
3733                         config = spa_generate_rootconf(devpath, devid, &guid);
3734                 }
3735         }
3736 #endif
3737         if (config == NULL) {
3738                 cmn_err(CE_NOTE, "Cannot read the pool label from '%s'",
3739                     devpath);
3740                 return (SET_ERROR(EIO));
3741         }
3742 
3743         VERIFY(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
3744             &pname) == 0);
3745         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
3746 
3747         mutex_enter(&spa_namespace_lock);
3748         if ((spa = spa_lookup(pname)) != NULL) {
3749                 /*
3750                  * Remove the existing root pool from the namespace so that we
3751                  * can replace it with the correct config we just read in.
3752                  */
3753                 spa_remove(spa);
3754         }
3755 
3756         spa = spa_add(pname, config, NULL);
3757         spa->spa_is_root = B_TRUE;
3758         spa->spa_import_flags = ZFS_IMPORT_VERBATIM;
3759 
3760         /*
3761          * Build up a vdev tree based on the boot device's label config.
3762          */
3763         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3764             &nvtop) == 0);
3765         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3766         error = spa_config_parse(spa, &rvd, nvtop, NULL, 0,
3767             VDEV_ALLOC_ROOTPOOL);
3768         spa_config_exit(spa, SCL_ALL, FTAG);
3769         if (error) {
3770                 mutex_exit(&spa_namespace_lock);
3771                 nvlist_free(config);
3772                 cmn_err(CE_NOTE, "Can not parse the config for pool '%s'",
3773                     pname);
3774                 return (error);
3775         }
3776 
3777         /*
3778          * Get the boot vdev.
3779          */
3780         if ((bvd = vdev_lookup_by_guid(rvd, guid)) == NULL) {
3781                 cmn_err(CE_NOTE, "Can not find the boot vdev for guid %llu",
3782                     (u_longlong_t)guid);
3783                 error = SET_ERROR(ENOENT);
3784                 goto out;
3785         }
3786 
3787         /*
3788          * Determine if there is a better boot device.
3789          */
3790         avd = bvd;
3791         spa_alt_rootvdev(rvd, &avd, &txg);
3792         if (avd != bvd) {
3793                 cmn_err(CE_NOTE, "The boot device is 'degraded'. Please "
3794                     "try booting from '%s'", avd->vdev_path);
3795                 error = SET_ERROR(EINVAL);
3796                 goto out;
3797         }
3798 
3799         /*
3800          * If the boot device is part of a spare vdev then ensure that
3801          * we're booting off the active spare.
3802          */
3803         if (bvd->vdev_parent->vdev_ops == &vdev_spare_ops &&
3804             !bvd->vdev_isspare) {
3805                 cmn_err(CE_NOTE, "The boot device is currently spared. Please "
3806                     "try booting from '%s'",
3807                     bvd->vdev_parent->
3808                     vdev_child[bvd->vdev_parent->vdev_children - 1]->vdev_path);
3809                 error = SET_ERROR(EINVAL);
3810                 goto out;
3811         }
3812 
3813         error = 0;
3814 out:
3815         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3816         vdev_free(rvd);
3817         spa_config_exit(spa, SCL_ALL, FTAG);
3818         mutex_exit(&spa_namespace_lock);
3819 
3820         nvlist_free(config);
3821         return (error);
3822 }
3823 
3824 #endif
3825 
3826 /*
3827  * Import a non-root pool into the system.
3828  */
3829 int
3830 spa_import(const char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
3831 {
3832         spa_t *spa;
3833         char *altroot = NULL;
3834         spa_load_state_t state = SPA_LOAD_IMPORT;
3835         zpool_rewind_policy_t policy;
3836         uint64_t mode = spa_mode_global;
3837         uint64_t readonly = B_FALSE;
3838         int error;
3839         nvlist_t *nvroot;
3840         nvlist_t **spares, **l2cache;
3841         uint_t nspares, nl2cache;
3842 
3843         /*
3844          * If a pool with this name exists, return failure.
3845          */
3846         mutex_enter(&spa_namespace_lock);
3847         if (spa_lookup(pool) != NULL) {
3848                 mutex_exit(&spa_namespace_lock);
3849                 return (SET_ERROR(EEXIST));
3850         }
3851 
3852         /*
3853          * Create and initialize the spa structure.
3854          */
3855         (void) nvlist_lookup_string(props,
3856             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3857         (void) nvlist_lookup_uint64(props,
3858             zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
3859         if (readonly)
3860                 mode = FREAD;
3861         spa = spa_add(pool, config, altroot);
3862         spa->spa_import_flags = flags;
3863 
3864         /*
3865          * Verbatim import - Take a pool and insert it into the namespace
3866          * as if it had been loaded at boot.
3867          */
3868         if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
3869                 if (props != NULL)
3870                         spa_configfile_set(spa, props, B_FALSE);
3871 
3872                 spa_config_sync(spa, B_FALSE, B_TRUE);
3873 
3874                 mutex_exit(&spa_namespace_lock);
3875                 return (0);
3876         }
3877 
3878         spa_activate(spa, mode);
3879 
3880         /*
3881          * Don't start async tasks until we know everything is healthy.
3882          */
3883         spa_async_suspend(spa);
3884 
3885         zpool_get_rewind_policy(config, &policy);
3886         if (policy.zrp_request & ZPOOL_DO_REWIND)
3887                 state = SPA_LOAD_RECOVER;
3888 
3889         /*
3890          * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
3891          * because the user-supplied config is actually the one to trust when
3892          * doing an import.
3893          */
3894         if (state != SPA_LOAD_RECOVER)
3895                 spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
3896 
3897         error = spa_load_best(spa, state, B_TRUE, policy.zrp_txg,
3898             policy.zrp_request);
3899 
3900         /*
3901          * Propagate anything learned while loading the pool and pass it
3902          * back to caller (i.e. rewind info, missing devices, etc).
3903          */
3904         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
3905             spa->spa_load_info) == 0);
3906 
3907         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3908         /*
3909          * Toss any existing sparelist, as it doesn't have any validity
3910          * anymore, and conflicts with spa_has_spare().
3911          */
3912         if (spa->spa_spares.sav_config) {
3913                 nvlist_free(spa->spa_spares.sav_config);
3914                 spa->spa_spares.sav_config = NULL;
3915                 spa_load_spares(spa);
3916         }
3917         if (spa->spa_l2cache.sav_config) {
3918                 nvlist_free(spa->spa_l2cache.sav_config);
3919                 spa->spa_l2cache.sav_config = NULL;
3920                 spa_load_l2cache(spa);
3921         }
3922 
3923         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3924             &nvroot) == 0);
3925         if (error == 0)
3926                 error = spa_validate_aux(spa, nvroot, -1ULL,
3927                     VDEV_ALLOC_SPARE);
3928         if (error == 0)
3929                 error = spa_validate_aux(spa, nvroot, -1ULL,
3930                     VDEV_ALLOC_L2CACHE);
3931         spa_config_exit(spa, SCL_ALL, FTAG);
3932 
3933         if (props != NULL)
3934                 spa_configfile_set(spa, props, B_FALSE);
3935 
3936         if (error != 0 || (props && spa_writeable(spa) &&
3937             (error = spa_prop_set(spa, props)))) {
3938                 spa_unload(spa);
3939                 spa_deactivate(spa);
3940                 spa_remove(spa);
3941                 mutex_exit(&spa_namespace_lock);
3942                 return (error);
3943         }
3944 
3945         spa_async_resume(spa);
3946 
3947         /*
3948          * Override any spares and level 2 cache devices as specified by
3949          * the user, as these may have correct device names/devids, etc.
3950          */
3951         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3952             &spares, &nspares) == 0) {
3953                 if (spa->spa_spares.sav_config)
3954                         VERIFY(nvlist_remove(spa->spa_spares.sav_config,
3955                             ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
3956                 else
3957                         VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
3958                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
3959                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3960                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3961                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3962                 spa_load_spares(spa);
3963                 spa_config_exit(spa, SCL_ALL, FTAG);
3964                 spa->spa_spares.sav_sync = B_TRUE;
3965         }
3966         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3967             &l2cache, &nl2cache) == 0) {
3968                 if (spa->spa_l2cache.sav_config)
3969                         VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
3970                             ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
3971                 else
3972                         VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3973                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
3974                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3975                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3976                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3977                 spa_load_l2cache(spa);
3978                 spa_config_exit(spa, SCL_ALL, FTAG);
3979                 spa->spa_l2cache.sav_sync = B_TRUE;
3980         }
3981 
3982         /*
3983          * Check for any removed devices.
3984          */
3985         if (spa->spa_autoreplace) {
3986                 spa_aux_check_removed(&spa->spa_spares);
3987                 spa_aux_check_removed(&spa->spa_l2cache);
3988         }
3989 
3990         if (spa_writeable(spa)) {
3991                 /*
3992                  * Update the config cache to include the newly-imported pool.
3993                  */
3994                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
3995         }
3996 
3997         /*
3998          * It's possible that the pool was expanded while it was exported.
3999          * We kick off an async task to handle this for us.
4000          */
4001         spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
4002 
4003         mutex_exit(&spa_namespace_lock);
4004         spa_history_log_version(spa, "import");
4005 
4006         return (0);
4007 }
4008 
4009 nvlist_t *
4010 spa_tryimport(nvlist_t *tryconfig)
4011 {
4012         nvlist_t *config = NULL;
4013         char *poolname;
4014         spa_t *spa;
4015         uint64_t state;
4016         int error;
4017 
4018         if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
4019                 return (NULL);
4020 
4021         if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
4022                 return (NULL);
4023 
4024         /*
4025          * Create and initialize the spa structure.
4026          */
4027         mutex_enter(&spa_namespace_lock);
4028         spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
4029         spa_activate(spa, FREAD);
4030 
4031         /*
4032          * Pass off the heavy lifting to spa_load().
4033          * Pass TRUE for mosconfig because the user-supplied config
4034          * is actually the one to trust when doing an import.
4035          */
4036         error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING, B_TRUE);
4037 
4038         /*
4039          * If 'tryconfig' was at least parsable, return the current config.
4040          */
4041         if (spa->spa_root_vdev != NULL) {
4042                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
4043                 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
4044                     poolname) == 0);
4045                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4046                     state) == 0);
4047                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
4048                     spa->spa_uberblock.ub_timestamp) == 0);
4049                 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
4050                     spa->spa_load_info) == 0);
4051 
4052                 /*
4053                  * If the bootfs property exists on this pool then we
4054                  * copy it out so that external consumers can tell which
4055                  * pools are bootable.
4056                  */
4057                 if ((!error || error == EEXIST) && spa->spa_bootfs) {
4058                         char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4059 
4060                         /*
4061                          * We have to play games with the name since the
4062                          * pool was opened as TRYIMPORT_NAME.
4063                          */
4064                         if (dsl_dsobj_to_dsname(spa_name(spa),
4065                             spa->spa_bootfs, tmpname) == 0) {
4066                                 char *cp;
4067                                 char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4068 
4069                                 cp = strchr(tmpname, '/');
4070                                 if (cp == NULL) {
4071                                         (void) strlcpy(dsname, tmpname,
4072                                             MAXPATHLEN);
4073                                 } else {
4074                                         (void) snprintf(dsname, MAXPATHLEN,
4075                                             "%s/%s", poolname, ++cp);
4076                                 }
4077                                 VERIFY(nvlist_add_string(config,
4078                                     ZPOOL_CONFIG_BOOTFS, dsname) == 0);
4079                                 kmem_free(dsname, MAXPATHLEN);
4080                         }
4081                         kmem_free(tmpname, MAXPATHLEN);
4082                 }
4083 
4084                 /*
4085                  * Add the list of hot spares and level 2 cache devices.
4086                  */
4087                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
4088                 spa_add_spares(spa, config);
4089                 spa_add_l2cache(spa, config);
4090                 spa_config_exit(spa, SCL_CONFIG, FTAG);
4091         }
4092 
4093         spa_unload(spa);
4094         spa_deactivate(spa);
4095         spa_remove(spa);
4096         mutex_exit(&spa_namespace_lock);
4097 
4098         return (config);
4099 }
4100 
4101 /*
4102  * Pool export/destroy
4103  *
4104  * The act of destroying or exporting a pool is very simple.  We make sure there
4105  * is no more pending I/O and any references to the pool are gone.  Then, we
4106  * update the pool state and sync all the labels to disk, removing the
4107  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
4108  * we don't sync the labels or remove the configuration cache.
4109  */
4110 static int
4111 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
4112     boolean_t force, boolean_t hardforce)
4113 {
4114         spa_t *spa;
4115 
4116         if (oldconfig)
4117                 *oldconfig = NULL;
4118 
4119         if (!(spa_mode_global & FWRITE))
4120                 return (SET_ERROR(EROFS));
4121 
4122         mutex_enter(&spa_namespace_lock);
4123         if ((spa = spa_lookup(pool)) == NULL) {
4124                 mutex_exit(&spa_namespace_lock);
4125                 return (SET_ERROR(ENOENT));
4126         }
4127 
4128         /*
4129          * Put a hold on the pool, drop the namespace lock, stop async tasks,
4130          * reacquire the namespace lock, and see if we can export.
4131          */
4132         spa_open_ref(spa, FTAG);
4133         mutex_exit(&spa_namespace_lock);
4134         spa_async_suspend(spa);
4135         mutex_enter(&spa_namespace_lock);
4136         spa_close(spa, FTAG);
4137 
4138         /*
4139          * The pool will be in core if it's openable,
4140          * in which case we can modify its state.
4141          */
4142         if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
4143                 /*
4144                  * Objsets may be open only because they're dirty, so we
4145                  * have to force it to sync before checking spa_refcnt.
4146                  */
4147                 txg_wait_synced(spa->spa_dsl_pool, 0);
4148 
4149                 /*
4150                  * A pool cannot be exported or destroyed if there are active
4151                  * references.  If we are resetting a pool, allow references by
4152                  * fault injection handlers.
4153                  */
4154                 if (!spa_refcount_zero(spa) ||
4155                     (spa->spa_inject_ref != 0 &&
4156                     new_state != POOL_STATE_UNINITIALIZED)) {
4157                         spa_async_resume(spa);
4158                         mutex_exit(&spa_namespace_lock);
4159                         return (SET_ERROR(EBUSY));
4160                 }
4161 
4162                 /*
4163                  * A pool cannot be exported if it has an active shared spare.
4164                  * This is to prevent other pools stealing the active spare
4165                  * from an exported pool. At user's own will, such pool can
4166                  * be forcedly exported.
4167                  */
4168                 if (!force && new_state == POOL_STATE_EXPORTED &&
4169                     spa_has_active_shared_spare(spa)) {
4170                         spa_async_resume(spa);
4171                         mutex_exit(&spa_namespace_lock);
4172                         return (SET_ERROR(EXDEV));
4173                 }
4174 
4175                 /*
4176                  * We want this to be reflected on every label,
4177                  * so mark them all dirty.  spa_unload() will do the
4178                  * final sync that pushes these changes out.
4179                  */
4180                 if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
4181                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4182                         spa->spa_state = new_state;
4183                         spa->spa_final_txg = spa_last_synced_txg(spa) +
4184                             TXG_DEFER_SIZE + 1;
4185                         vdev_config_dirty(spa->spa_root_vdev);
4186                         spa_config_exit(spa, SCL_ALL, FTAG);
4187                 }
4188         }
4189 
4190         spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
4191 
4192         if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
4193                 spa_unload(spa);
4194                 spa_deactivate(spa);
4195         }
4196 
4197         if (oldconfig && spa->spa_config)
4198                 VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
4199 
4200         if (new_state != POOL_STATE_UNINITIALIZED) {
4201                 if (!hardforce)
4202                         spa_config_sync(spa, B_TRUE, B_TRUE);
4203                 spa_remove(spa);
4204         }
4205         mutex_exit(&spa_namespace_lock);
4206 
4207         return (0);
4208 }
4209 
4210 /*
4211  * Destroy a storage pool.
4212  */
4213 int
4214 spa_destroy(char *pool)
4215 {
4216         return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
4217             B_FALSE, B_FALSE));
4218 }
4219 
4220 /*
4221  * Export a storage pool.
4222  */
4223 int
4224 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
4225     boolean_t hardforce)
4226 {
4227         return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
4228             force, hardforce));
4229 }
4230 
4231 /*
4232  * Similar to spa_export(), this unloads the spa_t without actually removing it
4233  * from the namespace in any way.
4234  */
4235 int
4236 spa_reset(char *pool)
4237 {
4238         return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
4239             B_FALSE, B_FALSE));
4240 }
4241 
4242 /*
4243  * ==========================================================================
4244  * Device manipulation
4245  * ==========================================================================
4246  */
4247 
4248 /*
4249  * Add a device to a storage pool.
4250  */
4251 int
4252 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
4253 {
4254         uint64_t txg, id;
4255         int error;
4256         vdev_t *rvd = spa->spa_root_vdev;
4257         vdev_t *vd, *tvd;
4258         nvlist_t **spares, **l2cache;
4259         uint_t nspares, nl2cache;
4260 
4261         ASSERT(spa_writeable(spa));
4262 
4263         txg = spa_vdev_enter(spa);
4264 
4265         if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
4266             VDEV_ALLOC_ADD)) != 0)
4267                 return (spa_vdev_exit(spa, NULL, txg, error));
4268 
4269         spa->spa_pending_vdev = vd;  /* spa_vdev_exit() will clear this */
4270 
4271         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
4272             &nspares) != 0)
4273                 nspares = 0;
4274 
4275         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
4276             &nl2cache) != 0)
4277                 nl2cache = 0;
4278 
4279         if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
4280                 return (spa_vdev_exit(spa, vd, txg, EINVAL));
4281 
4282         if (vd->vdev_children != 0 &&
4283             (error = vdev_create(vd, txg, B_FALSE)) != 0)
4284                 return (spa_vdev_exit(spa, vd, txg, error));
4285 
4286         /*
4287          * We must validate the spares and l2cache devices after checking the
4288          * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
4289          */
4290         if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
4291                 return (spa_vdev_exit(spa, vd, txg, error));
4292 
4293         /*
4294          * Transfer each new top-level vdev from vd to rvd.
4295          */
4296         for (int c = 0; c < vd->vdev_children; c++) {
4297 
4298                 /*
4299                  * Set the vdev id to the first hole, if one exists.
4300                  */
4301                 for (id = 0; id < rvd->vdev_children; id++) {
4302                         if (rvd->vdev_child[id]->vdev_ishole) {
4303                                 vdev_free(rvd->vdev_child[id]);
4304                                 break;
4305                         }
4306                 }
4307                 tvd = vd->vdev_child[c];
4308                 vdev_remove_child(vd, tvd);
4309                 tvd->vdev_id = id;
4310                 vdev_add_child(rvd, tvd);
4311                 vdev_config_dirty(tvd);
4312         }
4313 
4314         if (nspares != 0) {
4315                 spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
4316                     ZPOOL_CONFIG_SPARES);
4317                 spa_load_spares(spa);
4318                 spa->spa_spares.sav_sync = B_TRUE;
4319         }
4320 
4321         if (nl2cache != 0) {
4322                 spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
4323                     ZPOOL_CONFIG_L2CACHE);
4324                 spa_load_l2cache(spa);
4325                 spa->spa_l2cache.sav_sync = B_TRUE;
4326         }
4327 
4328         /*
4329          * We have to be careful when adding new vdevs to an existing pool.
4330          * If other threads start allocating from these vdevs before we
4331          * sync the config cache, and we lose power, then upon reboot we may
4332          * fail to open the pool because there are DVAs that the config cache
4333          * can't translate.  Therefore, we first add the vdevs without
4334          * initializing metaslabs; sync the config cache (via spa_vdev_exit());
4335          * and then let spa_config_update() initialize the new metaslabs.
4336          *
4337          * spa_load() checks for added-but-not-initialized vdevs, so that
4338          * if we lose power at any point in this sequence, the remaining
4339          * steps will be completed the next time we load the pool.
4340          */
4341         (void) spa_vdev_exit(spa, vd, txg, 0);
4342 
4343         mutex_enter(&spa_namespace_lock);
4344         spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4345         mutex_exit(&spa_namespace_lock);
4346 
4347         return (0);
4348 }
4349 
4350 /*
4351  * Attach a device to a mirror.  The arguments are the path to any device
4352  * in the mirror, and the nvroot for the new device.  If the path specifies
4353  * a device that is not mirrored, we automatically insert the mirror vdev.
4354  *
4355  * If 'replacing' is specified, the new device is intended to replace the
4356  * existing device; in this case the two devices are made into their own
4357  * mirror using the 'replacing' vdev, which is functionally identical to
4358  * the mirror vdev (it actually reuses all the same ops) but has a few
4359  * extra rules: you can't attach to it after it's been created, and upon
4360  * completion of resilvering, the first disk (the one being replaced)
4361  * is automatically detached.
4362  */
4363 int
4364 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
4365 {
4366         uint64_t txg, dtl_max_txg;
4367         vdev_t *rvd = spa->spa_root_vdev;
4368         vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
4369         vdev_ops_t *pvops;
4370         char *oldvdpath, *newvdpath;
4371         int newvd_isspare;
4372         int error;
4373 
4374         ASSERT(spa_writeable(spa));
4375 
4376         txg = spa_vdev_enter(spa);
4377 
4378         oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
4379 
4380         if (oldvd == NULL)
4381                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4382 
4383         if (!oldvd->vdev_ops->vdev_op_leaf)
4384                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4385 
4386         pvd = oldvd->vdev_parent;
4387 
4388         if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
4389             VDEV_ALLOC_ATTACH)) != 0)
4390                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4391 
4392         if (newrootvd->vdev_children != 1)
4393                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4394 
4395         newvd = newrootvd->vdev_child[0];
4396 
4397         if (!newvd->vdev_ops->vdev_op_leaf)
4398                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4399 
4400         if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
4401                 return (spa_vdev_exit(spa, newrootvd, txg, error));
4402 
4403         /*
4404          * Spares can't replace logs
4405          */
4406         if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
4407                 return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4408 
4409         if (!replacing) {
4410                 /*
4411                  * For attach, the only allowable parent is a mirror or the root
4412                  * vdev.
4413                  */
4414                 if (pvd->vdev_ops != &vdev_mirror_ops &&
4415                     pvd->vdev_ops != &vdev_root_ops)
4416                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4417 
4418                 pvops = &vdev_mirror_ops;
4419         } else {
4420                 /*
4421                  * Active hot spares can only be replaced by inactive hot
4422                  * spares.
4423                  */
4424                 if (pvd->vdev_ops == &vdev_spare_ops &&
4425                     oldvd->vdev_isspare &&
4426                     !spa_has_spare(spa, newvd->vdev_guid))
4427                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4428 
4429                 /*
4430                  * If the source is a hot spare, and the parent isn't already a
4431                  * spare, then we want to create a new hot spare.  Otherwise, we
4432                  * want to create a replacing vdev.  The user is not allowed to
4433                  * attach to a spared vdev child unless the 'isspare' state is
4434                  * the same (spare replaces spare, non-spare replaces
4435                  * non-spare).
4436                  */
4437                 if (pvd->vdev_ops == &vdev_replacing_ops &&
4438                     spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
4439                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4440                 } else if (pvd->vdev_ops == &vdev_spare_ops &&
4441                     newvd->vdev_isspare != oldvd->vdev_isspare) {
4442                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4443                 }
4444 
4445                 if (newvd->vdev_isspare)
4446                         pvops = &vdev_spare_ops;
4447                 else
4448                         pvops = &vdev_replacing_ops;
4449         }
4450 
4451         /*
4452          * Make sure the new device is big enough.
4453          */
4454         if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
4455                 return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
4456 
4457         /*
4458          * The new device cannot have a higher alignment requirement
4459          * than the top-level vdev.
4460          */
4461         if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
4462                 return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
4463 
4464         /*
4465          * If this is an in-place replacement, update oldvd's path and devid
4466          * to make it distinguishable from newvd, and unopenable from now on.
4467          */
4468         if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
4469                 spa_strfree(oldvd->vdev_path);
4470                 oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
4471                     KM_SLEEP);
4472                 (void) sprintf(oldvd->vdev_path, "%s/%s",
4473                     newvd->vdev_path, "old");
4474                 if (oldvd->vdev_devid != NULL) {
4475                         spa_strfree(oldvd->vdev_devid);
4476                         oldvd->vdev_devid = NULL;
4477                 }
4478         }
4479 
4480         /* mark the device being resilvered */
4481         newvd->vdev_resilver_txg = txg;
4482 
4483         /*
4484          * If the parent is not a mirror, or if we're replacing, insert the new
4485          * mirror/replacing/spare vdev above oldvd.
4486          */
4487         if (pvd->vdev_ops != pvops)
4488                 pvd = vdev_add_parent(oldvd, pvops);
4489 
4490         ASSERT(pvd->vdev_top->vdev_parent == rvd);
4491         ASSERT(pvd->vdev_ops == pvops);
4492         ASSERT(oldvd->vdev_parent == pvd);
4493 
4494         /*
4495          * Extract the new device from its root and add it to pvd.
4496          */
4497         vdev_remove_child(newrootvd, newvd);
4498         newvd->vdev_id = pvd->vdev_children;
4499         newvd->vdev_crtxg = oldvd->vdev_crtxg;
4500         vdev_add_child(pvd, newvd);
4501 
4502         tvd = newvd->vdev_top;
4503         ASSERT(pvd->vdev_top == tvd);
4504         ASSERT(tvd->vdev_parent == rvd);
4505 
4506         vdev_config_dirty(tvd);
4507 
4508         /*
4509          * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
4510          * for any dmu_sync-ed blocks.  It will propagate upward when
4511          * spa_vdev_exit() calls vdev_dtl_reassess().
4512          */
4513         dtl_max_txg = txg + TXG_CONCURRENT_STATES;
4514 
4515         vdev_dtl_dirty(newvd, DTL_MISSING, TXG_INITIAL,
4516             dtl_max_txg - TXG_INITIAL);
4517 
4518         if (newvd->vdev_isspare) {
4519                 spa_spare_activate(newvd);
4520                 spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
4521         }
4522 
4523         oldvdpath = spa_strdup(oldvd->vdev_path);
4524         newvdpath = spa_strdup(newvd->vdev_path);
4525         newvd_isspare = newvd->vdev_isspare;
4526 
4527         /*
4528          * Mark newvd's DTL dirty in this txg.
4529          */
4530         vdev_dirty(tvd, VDD_DTL, newvd, txg);
4531 
4532         /*
4533          * Schedule the resilver to restart in the future. We do this to
4534          * ensure that dmu_sync-ed blocks have been stitched into the
4535          * respective datasets.
4536          */
4537         dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
4538 
4539         /*
4540          * Commit the config
4541          */
4542         (void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
4543 
4544         spa_history_log_internal(spa, "vdev attach", NULL,
4545             "%s vdev=%s %s vdev=%s",
4546             replacing && newvd_isspare ? "spare in" :
4547             replacing ? "replace" : "attach", newvdpath,
4548             replacing ? "for" : "to", oldvdpath);
4549 
4550         spa_strfree(oldvdpath);
4551         spa_strfree(newvdpath);
4552 
4553         if (spa->spa_bootfs)
4554                 spa_event_notify(spa, newvd, ESC_ZFS_BOOTFS_VDEV_ATTACH);
4555 
4556         return (0);
4557 }
4558 
4559 /*
4560  * Detach a device from a mirror or replacing vdev.
4561  *
4562  * If 'replace_done' is specified, only detach if the parent
4563  * is a replacing vdev.
4564  */
4565 int
4566 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
4567 {
4568         uint64_t txg;
4569         int error;
4570         vdev_t *rvd = spa->spa_root_vdev;
4571         vdev_t *vd, *pvd, *cvd, *tvd;
4572         boolean_t unspare = B_FALSE;
4573         uint64_t unspare_guid = 0;
4574         char *vdpath;
4575 
4576         ASSERT(spa_writeable(spa));
4577 
4578         txg = spa_vdev_enter(spa);
4579 
4580         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4581 
4582         if (vd == NULL)
4583                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4584 
4585         if (!vd->vdev_ops->vdev_op_leaf)
4586                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4587 
4588         pvd = vd->vdev_parent;
4589 
4590         /*
4591          * If the parent/child relationship is not as expected, don't do it.
4592          * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
4593          * vdev that's replacing B with C.  The user's intent in replacing
4594          * is to go from M(A,B) to M(A,C).  If the user decides to cancel
4595          * the replace by detaching C, the expected behavior is to end up
4596          * M(A,B).  But suppose that right after deciding to detach C,
4597          * the replacement of B completes.  We would have M(A,C), and then
4598          * ask to detach C, which would leave us with just A -- not what
4599          * the user wanted.  To prevent this, we make sure that the
4600          * parent/child relationship hasn't changed -- in this example,
4601          * that C's parent is still the replacing vdev R.
4602          */
4603         if (pvd->vdev_guid != pguid && pguid != 0)
4604                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4605 
4606         /*
4607          * Only 'replacing' or 'spare' vdevs can be replaced.
4608          */
4609         if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
4610             pvd->vdev_ops != &vdev_spare_ops)
4611                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4612 
4613         ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
4614             spa_version(spa) >= SPA_VERSION_SPARES);
4615 
4616         /*
4617          * Only mirror, replacing, and spare vdevs support detach.
4618          */
4619         if (pvd->vdev_ops != &vdev_replacing_ops &&
4620             pvd->vdev_ops != &vdev_mirror_ops &&
4621             pvd->vdev_ops != &vdev_spare_ops)
4622                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4623 
4624         /*
4625          * If this device has the only valid copy of some data,
4626          * we cannot safely detach it.
4627          */
4628         if (vdev_dtl_required(vd))
4629                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4630 
4631         ASSERT(pvd->vdev_children >= 2);
4632 
4633         /*
4634          * If we are detaching the second disk from a replacing vdev, then
4635          * check to see if we changed the original vdev's path to have "/old"
4636          * at the end in spa_vdev_attach().  If so, undo that change now.
4637          */
4638         if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
4639             vd->vdev_path != NULL) {
4640                 size_t len = strlen(vd->vdev_path);
4641 
4642                 for (int c = 0; c < pvd->vdev_children; c++) {
4643                         cvd = pvd->vdev_child[c];
4644 
4645                         if (cvd == vd || cvd->vdev_path == NULL)
4646                                 continue;
4647 
4648                         if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
4649                             strcmp(cvd->vdev_path + len, "/old") == 0) {
4650                                 spa_strfree(cvd->vdev_path);
4651                                 cvd->vdev_path = spa_strdup(vd->vdev_path);
4652                                 break;
4653                         }
4654                 }
4655         }
4656 
4657         /*
4658          * If we are detaching the original disk from a spare, then it implies
4659          * that the spare should become a real disk, and be removed from the
4660          * active spare list for the pool.
4661          */
4662         if (pvd->vdev_ops == &vdev_spare_ops &&
4663             vd->vdev_id == 0 &&
4664             pvd->vdev_child[pvd->vdev_children - 1]->vdev_isspare)
4665                 unspare = B_TRUE;
4666 
4667         /*
4668          * Erase the disk labels so the disk can be used for other things.
4669          * This must be done after all other error cases are handled,
4670          * but before we disembowel vd (so we can still do I/O to it).
4671          * But if we can't do it, don't treat the error as fatal --
4672          * it may be that the unwritability of the disk is the reason
4673          * it's being detached!
4674          */
4675         error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4676 
4677         /*
4678          * Remove vd from its parent and compact the parent's children.
4679          */
4680         vdev_remove_child(pvd, vd);
4681         vdev_compact_children(pvd);
4682 
4683         /*
4684          * Remember one of the remaining children so we can get tvd below.
4685          */
4686         cvd = pvd->vdev_child[pvd->vdev_children - 1];
4687 
4688         /*
4689          * If we need to remove the remaining child from the list of hot spares,
4690          * do it now, marking the vdev as no longer a spare in the process.
4691          * We must do this before vdev_remove_parent(), because that can
4692          * change the GUID if it creates a new toplevel GUID.  For a similar
4693          * reason, we must remove the spare now, in the same txg as the detach;
4694          * otherwise someone could attach a new sibling, change the GUID, and
4695          * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
4696          */
4697         if (unspare) {
4698                 ASSERT(cvd->vdev_isspare);
4699                 spa_spare_remove(cvd);
4700                 unspare_guid = cvd->vdev_guid;
4701                 (void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
4702                 cvd->vdev_unspare = B_TRUE;
4703         }
4704 
4705         /*
4706          * If the parent mirror/replacing vdev only has one child,
4707          * the parent is no longer needed.  Remove it from the tree.
4708          */
4709         if (pvd->vdev_children == 1) {
4710                 if (pvd->vdev_ops == &vdev_spare_ops)
4711                         cvd->vdev_unspare = B_FALSE;
4712                 vdev_remove_parent(cvd);
4713         }
4714 
4715 
4716         /*
4717          * We don't set tvd until now because the parent we just removed
4718          * may have been the previous top-level vdev.
4719          */
4720         tvd = cvd->vdev_top;
4721         ASSERT(tvd->vdev_parent == rvd);
4722 
4723         /*
4724          * Reevaluate the parent vdev state.
4725          */
4726         vdev_propagate_state(cvd);
4727 
4728         /*
4729          * If the 'autoexpand' property is set on the pool then automatically
4730          * try to expand the size of the pool. For example if the device we
4731          * just detached was smaller than the others, it may be possible to
4732          * add metaslabs (i.e. grow the pool). We need to reopen the vdev
4733          * first so that we can obtain the updated sizes of the leaf vdevs.
4734          */
4735         if (spa->spa_autoexpand) {
4736                 vdev_reopen(tvd);
4737                 vdev_expand(tvd, txg);
4738         }
4739 
4740         vdev_config_dirty(tvd);
4741 
4742         /*
4743          * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
4744          * vd->vdev_detached is set and free vd's DTL object in syncing context.
4745          * But first make sure we're not on any *other* txg's DTL list, to
4746          * prevent vd from being accessed after it's freed.
4747          */
4748         vdpath = spa_strdup(vd->vdev_path);
4749         for (int t = 0; t < TXG_SIZE; t++)
4750                 (void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
4751         vd->vdev_detached = B_TRUE;
4752         vdev_dirty(tvd, VDD_DTL, vd, txg);
4753 
4754         spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
4755 
4756         /* hang on to the spa before we release the lock */
4757         spa_open_ref(spa, FTAG);
4758 
4759         error = spa_vdev_exit(spa, vd, txg, 0);
4760 
4761         spa_history_log_internal(spa, "detach", NULL,
4762             "vdev=%s", vdpath);
4763         spa_strfree(vdpath);
4764 
4765         /*
4766          * If this was the removal of the original device in a hot spare vdev,
4767          * then we want to go through and remove the device from the hot spare
4768          * list of every other pool.
4769          */
4770         if (unspare) {
4771                 spa_t *altspa = NULL;
4772 
4773                 mutex_enter(&spa_namespace_lock);
4774                 while ((altspa = spa_next(altspa)) != NULL) {
4775                         if (altspa->spa_state != POOL_STATE_ACTIVE ||
4776                             altspa == spa)
4777                                 continue;
4778 
4779                         spa_open_ref(altspa, FTAG);
4780                         mutex_exit(&spa_namespace_lock);
4781                         (void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
4782                         mutex_enter(&spa_namespace_lock);
4783                         spa_close(altspa, FTAG);
4784                 }
4785                 mutex_exit(&spa_namespace_lock);
4786 
4787                 /* search the rest of the vdevs for spares to remove */
4788                 spa_vdev_resilver_done(spa);
4789         }
4790 
4791         /* all done with the spa; OK to release */
4792         mutex_enter(&spa_namespace_lock);
4793         spa_close(spa, FTAG);
4794         mutex_exit(&spa_namespace_lock);
4795 
4796         return (error);
4797 }
4798 
4799 /*
4800  * Split a set of devices from their mirrors, and create a new pool from them.
4801  */
4802 int
4803 spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
4804     nvlist_t *props, boolean_t exp)
4805 {
4806         int error = 0;
4807         uint64_t txg, *glist;
4808         spa_t *newspa;
4809         uint_t c, children, lastlog;
4810         nvlist_t **child, *nvl, *tmp;
4811         dmu_tx_t *tx;
4812         char *altroot = NULL;
4813         vdev_t *rvd, **vml = NULL;                      /* vdev modify list */
4814         boolean_t activate_slog;
4815 
4816         ASSERT(spa_writeable(spa));
4817 
4818         txg = spa_vdev_enter(spa);
4819 
4820         /* clear the log and flush everything up to now */
4821         activate_slog = spa_passivate_log(spa);
4822         (void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4823         error = spa_offline_log(spa);
4824         txg = spa_vdev_config_enter(spa);
4825 
4826         if (activate_slog)
4827                 spa_activate_log(spa);
4828 
4829         if (error != 0)
4830                 return (spa_vdev_exit(spa, NULL, txg, error));
4831 
4832         /* check new spa name before going any further */
4833         if (spa_lookup(newname) != NULL)
4834                 return (spa_vdev_exit(spa, NULL, txg, EEXIST));
4835 
4836         /*
4837          * scan through all the children to ensure they're all mirrors
4838          */
4839         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
4840             nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
4841             &children) != 0)
4842                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4843 
4844         /* first, check to ensure we've got the right child count */
4845         rvd = spa->spa_root_vdev;
4846         lastlog = 0;
4847         for (c = 0; c < rvd->vdev_children; c++) {
4848                 vdev_t *vd = rvd->vdev_child[c];
4849 
4850                 /* don't count the holes & logs as children */
4851                 if (vd->vdev_islog || vd->vdev_ishole) {
4852                         if (lastlog == 0)
4853                                 lastlog = c;
4854                         continue;
4855                 }
4856 
4857                 lastlog = 0;
4858         }
4859         if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
4860                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4861 
4862         /* next, ensure no spare or cache devices are part of the split */
4863         if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
4864             nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
4865                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4866 
4867         vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
4868         glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
4869 
4870         /* then, loop over each vdev and validate it */
4871         for (c = 0; c < children; c++) {
4872                 uint64_t is_hole = 0;
4873 
4874                 (void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
4875                     &is_hole);
4876 
4877                 if (is_hole != 0) {
4878                         if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
4879                             spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
4880                                 continue;
4881                         } else {
4882                                 error = SET_ERROR(EINVAL);
4883                                 break;
4884                         }
4885                 }
4886 
4887                 /* which disk is going to be split? */
4888                 if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
4889                     &glist[c]) != 0) {
4890                         error = SET_ERROR(EINVAL);
4891                         break;
4892                 }
4893 
4894                 /* look it up in the spa */
4895                 vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
4896                 if (vml[c] == NULL) {
4897                         error = SET_ERROR(ENODEV);
4898                         break;
4899                 }
4900 
4901                 /* make sure there's nothing stopping the split */
4902                 if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
4903                     vml[c]->vdev_islog ||
4904                     vml[c]->vdev_ishole ||
4905                     vml[c]->vdev_isspare ||
4906                     vml[c]->vdev_isl2cache ||
4907                     !vdev_writeable(vml[c]) ||
4908                     vml[c]->vdev_children != 0 ||
4909                     vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
4910                     c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
4911                         error = SET_ERROR(EINVAL);
4912                         break;
4913                 }
4914 
4915                 if (vdev_dtl_required(vml[c])) {
4916                         error = SET_ERROR(EBUSY);
4917                         break;
4918                 }
4919 
4920                 /* we need certain info from the top level */
4921                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
4922                     vml[c]->vdev_top->vdev_ms_array) == 0);
4923                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
4924                     vml[c]->vdev_top->vdev_ms_shift) == 0);
4925                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
4926                     vml[c]->vdev_top->vdev_asize) == 0);
4927                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
4928                     vml[c]->vdev_top->vdev_ashift) == 0);
4929         }
4930 
4931         if (error != 0) {
4932                 kmem_free(vml, children * sizeof (vdev_t *));
4933                 kmem_free(glist, children * sizeof (uint64_t));
4934                 return (spa_vdev_exit(spa, NULL, txg, error));
4935         }
4936 
4937         /* stop writers from using the disks */
4938         for (c = 0; c < children; c++) {
4939                 if (vml[c] != NULL)
4940                         vml[c]->vdev_offline = B_TRUE;
4941         }
4942         vdev_reopen(spa->spa_root_vdev);
4943 
4944         /*
4945          * Temporarily record the splitting vdevs in the spa config.  This
4946          * will disappear once the config is regenerated.
4947          */
4948         VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0);
4949         VERIFY(nvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
4950             glist, children) == 0);
4951         kmem_free(glist, children * sizeof (uint64_t));
4952 
4953         mutex_enter(&spa->spa_props_lock);
4954         VERIFY(nvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT,
4955             nvl) == 0);
4956         mutex_exit(&spa->spa_props_lock);
4957         spa->spa_config_splitting = nvl;
4958         vdev_config_dirty(spa->spa_root_vdev);
4959 
4960         /* configure and create the new pool */
4961         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname) == 0);
4962         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4963             exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE) == 0);
4964         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
4965             spa_version(spa)) == 0);
4966         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
4967             spa->spa_config_txg) == 0);
4968         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
4969             spa_generate_guid(NULL)) == 0);
4970         (void) nvlist_lookup_string(props,
4971             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
4972 
4973         /* add the new pool to the namespace */
4974         newspa = spa_add(newname, config, altroot);
4975         newspa->spa_config_txg = spa->spa_config_txg;
4976         spa_set_log_state(newspa, SPA_LOG_CLEAR);
4977 
4978         /* release the spa config lock, retaining the namespace lock */
4979         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4980 
4981         if (zio_injection_enabled)
4982                 zio_handle_panic_injection(spa, FTAG, 1);
4983 
4984         spa_activate(newspa, spa_mode_global);
4985         spa_async_suspend(newspa);
4986 
4987         /* create the new pool from the disks of the original pool */
4988         error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE, B_TRUE);
4989         if (error)
4990                 goto out;
4991 
4992         /* if that worked, generate a real config for the new pool */
4993         if (newspa->spa_root_vdev != NULL) {
4994                 VERIFY(nvlist_alloc(&newspa->spa_config_splitting,
4995                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
4996                 VERIFY(nvlist_add_uint64(newspa->spa_config_splitting,
4997                     ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa)) == 0);
4998                 spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
4999                     B_TRUE));
5000         }
5001 
5002         /* set the props */
5003         if (props != NULL) {
5004                 spa_configfile_set(newspa, props, B_FALSE);
5005                 error = spa_prop_set(newspa, props);
5006                 if (error)
5007                         goto out;
5008         }
5009 
5010         /* flush everything */
5011         txg = spa_vdev_config_enter(newspa);
5012         vdev_config_dirty(newspa->spa_root_vdev);
5013         (void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
5014 
5015         if (zio_injection_enabled)
5016                 zio_handle_panic_injection(spa, FTAG, 2);
5017 
5018         spa_async_resume(newspa);
5019 
5020         /* finally, update the original pool's config */
5021         txg = spa_vdev_config_enter(spa);
5022         tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
5023         error = dmu_tx_assign(tx, TXG_WAIT);
5024         if (error != 0)
5025                 dmu_tx_abort(tx);
5026         for (c = 0; c < children; c++) {
5027                 if (vml[c] != NULL) {
5028                         vdev_split(vml[c]);
5029                         if (error == 0)
5030                                 spa_history_log_internal(spa, "detach", tx,
5031                                     "vdev=%s", vml[c]->vdev_path);
5032                         vdev_free(vml[c]);
5033                 }
5034         }
5035         vdev_config_dirty(spa->spa_root_vdev);
5036         spa->spa_config_splitting = NULL;
5037         nvlist_free(nvl);
5038         if (error == 0)
5039                 dmu_tx_commit(tx);
5040         (void) spa_vdev_exit(spa, NULL, txg, 0);
5041 
5042         if (zio_injection_enabled)
5043                 zio_handle_panic_injection(spa, FTAG, 3);
5044 
5045         /* split is complete; log a history record */
5046         spa_history_log_internal(newspa, "split", NULL,
5047             "from pool %s", spa_name(spa));
5048 
5049         kmem_free(vml, children * sizeof (vdev_t *));
5050 
5051         /* if we're not going to mount the filesystems in userland, export */
5052         if (exp)
5053                 error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
5054                     B_FALSE, B_FALSE);
5055 
5056         return (error);
5057 
5058 out:
5059         spa_unload(newspa);
5060         spa_deactivate(newspa);
5061         spa_remove(newspa);
5062 
5063         txg = spa_vdev_config_enter(spa);
5064 
5065         /* re-online all offlined disks */
5066         for (c = 0; c < children; c++) {
5067                 if (vml[c] != NULL)
5068                         vml[c]->vdev_offline = B_FALSE;
5069         }
5070         vdev_reopen(spa->spa_root_vdev);
5071 
5072         nvlist_free(spa->spa_config_splitting);
5073         spa->spa_config_splitting = NULL;
5074         (void) spa_vdev_exit(spa, NULL, txg, error);
5075 
5076         kmem_free(vml, children * sizeof (vdev_t *));
5077         return (error);
5078 }
5079 
5080 static nvlist_t *
5081 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
5082 {
5083         for (int i = 0; i < count; i++) {
5084                 uint64_t guid;
5085 
5086                 VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
5087                     &guid) == 0);
5088 
5089                 if (guid == target_guid)
5090                         return (nvpp[i]);
5091         }
5092 
5093         return (NULL);
5094 }
5095 
5096 static void
5097 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
5098         nvlist_t *dev_to_remove)
5099 {
5100         nvlist_t **newdev = NULL;
5101 
5102         if (count > 1)
5103                 newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
5104 
5105         for (int i = 0, j = 0; i < count; i++) {
5106                 if (dev[i] == dev_to_remove)
5107                         continue;
5108                 VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
5109         }
5110 
5111         VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
5112         VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
5113 
5114         for (int i = 0; i < count - 1; i++)
5115                 nvlist_free(newdev[i]);
5116 
5117         if (count > 1)
5118                 kmem_free(newdev, (count - 1) * sizeof (void *));
5119 }
5120 
5121 /*
5122  * Evacuate the device.
5123  */
5124 static int
5125 spa_vdev_remove_evacuate(spa_t *spa, vdev_t *vd)
5126 {
5127         uint64_t txg;
5128         int error = 0;
5129 
5130         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5131         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5132         ASSERT(vd == vd->vdev_top);
5133 
5134         /*
5135          * Evacuate the device.  We don't hold the config lock as writer
5136          * since we need to do I/O but we do keep the
5137          * spa_namespace_lock held.  Once this completes the device
5138          * should no longer have any blocks allocated on it.
5139          */
5140         if (vd->vdev_islog) {
5141                 if (vd->vdev_stat.vs_alloc != 0)
5142                         error = spa_offline_log(spa);
5143         } else {
5144                 error = SET_ERROR(ENOTSUP);
5145         }
5146 
5147         if (error)
5148                 return (error);
5149 
5150         /*
5151          * The evacuation succeeded.  Remove any remaining MOS metadata
5152          * associated with this vdev, and wait for these changes to sync.
5153          */
5154         ASSERT0(vd->vdev_stat.vs_alloc);
5155         txg = spa_vdev_config_enter(spa);
5156         vd->vdev_removing = B_TRUE;
5157         vdev_dirty_leaves(vd, VDD_DTL, txg);
5158         vdev_config_dirty(vd);
5159         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
5160 
5161         return (0);
5162 }
5163 
5164 /*
5165  * Complete the removal by cleaning up the namespace.
5166  */
5167 static void
5168 spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
5169 {
5170         vdev_t *rvd = spa->spa_root_vdev;
5171         uint64_t id = vd->vdev_id;
5172         boolean_t last_vdev = (id == (rvd->vdev_children - 1));
5173 
5174         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5175         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
5176         ASSERT(vd == vd->vdev_top);
5177 
5178         /*
5179          * Only remove any devices which are empty.
5180          */
5181         if (vd->vdev_stat.vs_alloc != 0)
5182                 return;
5183 
5184         (void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
5185 
5186         if (list_link_active(&vd->vdev_state_dirty_node))
5187                 vdev_state_clean(vd);
5188         if (list_link_active(&vd->vdev_config_dirty_node))
5189                 vdev_config_clean(vd);
5190 
5191         vdev_free(vd);
5192 
5193         if (last_vdev) {
5194                 vdev_compact_children(rvd);
5195         } else {
5196                 vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops);
5197                 vdev_add_child(rvd, vd);
5198         }
5199         vdev_config_dirty(rvd);
5200 
5201         /*
5202          * Reassess the health of our root vdev.
5203          */
5204         vdev_reopen(rvd);
5205 }
5206 
5207 /*
5208  * Remove a device from the pool -
5209  *
5210  * Removing a device from the vdev namespace requires several steps
5211  * and can take a significant amount of time.  As a result we use
5212  * the spa_vdev_config_[enter/exit] functions which allow us to
5213  * grab and release the spa_config_lock while still holding the namespace
5214  * lock.  During each step the configuration is synced out.
5215  *
5216  * Currently, this supports removing only hot spares, slogs, and level 2 ARC
5217  * devices.
5218  */
5219 int
5220 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
5221 {
5222         vdev_t *vd;
5223         metaslab_group_t *mg;
5224         nvlist_t **spares, **l2cache, *nv;
5225         uint64_t txg = 0;
5226         uint_t nspares, nl2cache;
5227         int error = 0;
5228         boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
5229 
5230         ASSERT(spa_writeable(spa));
5231 
5232         if (!locked)
5233                 txg = spa_vdev_enter(spa);
5234 
5235         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
5236 
5237         if (spa->spa_spares.sav_vdevs != NULL &&
5238             nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
5239             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
5240             (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
5241                 /*
5242                  * Only remove the hot spare if it's not currently in use
5243                  * in this pool.
5244                  */
5245                 if (vd == NULL || unspare) {
5246                         spa_vdev_remove_aux(spa->spa_spares.sav_config,
5247                             ZPOOL_CONFIG_SPARES, spares, nspares, nv);
5248                         spa_load_spares(spa);
5249                         spa->spa_spares.sav_sync = B_TRUE;
5250                 } else {
5251                         error = SET_ERROR(EBUSY);
5252                 }
5253         } else if (spa->spa_l2cache.sav_vdevs != NULL &&
5254             nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
5255             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
5256             (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
5257                 /*
5258                  * Cache devices can always be removed.
5259                  */
5260                 spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
5261                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
5262                 spa_load_l2cache(spa);
5263                 spa->spa_l2cache.sav_sync = B_TRUE;
5264         } else if (vd != NULL && vd->vdev_islog) {
5265                 ASSERT(!locked);
5266                 ASSERT(vd == vd->vdev_top);
5267 
5268                 mg = vd->vdev_mg;
5269 
5270                 /*
5271                  * Stop allocating from this vdev.
5272                  */
5273                 metaslab_group_passivate(mg);
5274 
5275                 /*
5276                  * Wait for the youngest allocations and frees to sync,
5277                  * and then wait for the deferral of those frees to finish.
5278                  */
5279                 spa_vdev_config_exit(spa, NULL,
5280                     txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
5281 
5282                 /*
5283                  * Attempt to evacuate the vdev.
5284                  */
5285                 error = spa_vdev_remove_evacuate(spa, vd);
5286 
5287                 txg = spa_vdev_config_enter(spa);
5288 
5289                 /*
5290                  * If we couldn't evacuate the vdev, unwind.
5291                  */
5292                 if (error) {
5293                         metaslab_group_activate(mg);
5294                         return (spa_vdev_exit(spa, NULL, txg, error));
5295                 }
5296 
5297                 /*
5298                  * Clean up the vdev namespace.
5299                  */
5300                 spa_vdev_remove_from_namespace(spa, vd);
5301 
5302         } else if (vd != NULL) {
5303                 /*
5304                  * Normal vdevs cannot be removed (yet).
5305                  */
5306                 error = SET_ERROR(ENOTSUP);
5307         } else {
5308                 /*
5309                  * There is no vdev of any kind with the specified guid.
5310                  */
5311                 error = SET_ERROR(ENOENT);
5312         }
5313 
5314         if (!locked)
5315                 return (spa_vdev_exit(spa, NULL, txg, error));
5316 
5317         return (error);
5318 }
5319 
5320 /*
5321  * Find any device that's done replacing, or a vdev marked 'unspare' that's
5322  * currently spared, so we can detach it.
5323  */
5324 static vdev_t *
5325 spa_vdev_resilver_done_hunt(vdev_t *vd)
5326 {
5327         vdev_t *newvd, *oldvd;
5328 
5329         for (int c = 0; c < vd->vdev_children; c++) {
5330                 oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
5331                 if (oldvd != NULL)
5332                         return (oldvd);
5333         }
5334 
5335         /*
5336          * Check for a completed replacement.  We always consider the first
5337          * vdev in the list to be the oldest vdev, and the last one to be
5338          * the newest (see spa_vdev_attach() for how that works).  In
5339          * the case where the newest vdev is faulted, we will not automatically
5340          * remove it after a resilver completes.  This is OK as it will require
5341          * user intervention to determine which disk the admin wishes to keep.
5342          */
5343         if (vd->vdev_ops == &vdev_replacing_ops) {
5344                 ASSERT(vd->vdev_children > 1);
5345 
5346                 newvd = vd->vdev_child[vd->vdev_children - 1];
5347                 oldvd = vd->vdev_child[0];
5348 
5349                 if (vdev_dtl_empty(newvd, DTL_MISSING) &&
5350                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5351                     !vdev_dtl_required(oldvd))
5352                         return (oldvd);
5353         }
5354 
5355         /*
5356          * Check for a completed resilver with the 'unspare' flag set.
5357          */
5358         if (vd->vdev_ops == &vdev_spare_ops) {
5359                 vdev_t *first = vd->vdev_child[0];
5360                 vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
5361 
5362                 if (last->vdev_unspare) {
5363                         oldvd = first;
5364                         newvd = last;
5365                 } else if (first->vdev_unspare) {
5366                         oldvd = last;
5367                         newvd = first;
5368                 } else {
5369                         oldvd = NULL;
5370                 }
5371 
5372                 if (oldvd != NULL &&
5373                     vdev_dtl_empty(newvd, DTL_MISSING) &&
5374                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5375                     !vdev_dtl_required(oldvd))
5376                         return (oldvd);
5377 
5378                 /*
5379                  * If there are more than two spares attached to a disk,
5380                  * and those spares are not required, then we want to
5381                  * attempt to free them up now so that they can be used
5382                  * by other pools.  Once we're back down to a single
5383                  * disk+spare, we stop removing them.
5384                  */
5385                 if (vd->vdev_children > 2) {
5386                         newvd = vd->vdev_child[1];
5387 
5388                         if (newvd->vdev_isspare && last->vdev_isspare &&
5389                             vdev_dtl_empty(last, DTL_MISSING) &&
5390                             vdev_dtl_empty(last, DTL_OUTAGE) &&
5391                             !vdev_dtl_required(newvd))
5392                                 return (newvd);
5393                 }
5394         }
5395 
5396         return (NULL);
5397 }
5398 
5399 static void
5400 spa_vdev_resilver_done(spa_t *spa)
5401 {
5402         vdev_t *vd, *pvd, *ppvd;
5403         uint64_t guid, sguid, pguid, ppguid;
5404 
5405         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5406 
5407         while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
5408                 pvd = vd->vdev_parent;
5409                 ppvd = pvd->vdev_parent;
5410                 guid = vd->vdev_guid;
5411                 pguid = pvd->vdev_guid;
5412                 ppguid = ppvd->vdev_guid;
5413                 sguid = 0;
5414                 /*
5415                  * If we have just finished replacing a hot spared device, then
5416                  * we need to detach the parent's first child (the original hot
5417                  * spare) as well.
5418                  */
5419                 if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
5420                     ppvd->vdev_children == 2) {
5421                         ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
5422                         sguid = ppvd->vdev_child[1]->vdev_guid;
5423                 }
5424                 ASSERT(vd->vdev_resilver_txg == 0 || !vdev_dtl_required(vd));
5425 
5426                 spa_config_exit(spa, SCL_ALL, FTAG);
5427                 if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
5428                         return;
5429                 if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
5430                         return;
5431                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5432         }
5433 
5434         spa_config_exit(spa, SCL_ALL, FTAG);
5435 }
5436 
5437 /*
5438  * Update the stored path or FRU for this vdev.
5439  */
5440 int
5441 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
5442     boolean_t ispath)
5443 {
5444         vdev_t *vd;
5445         boolean_t sync = B_FALSE;
5446 
5447         ASSERT(spa_writeable(spa));
5448 
5449         spa_vdev_state_enter(spa, SCL_ALL);
5450 
5451         if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
5452                 return (spa_vdev_state_exit(spa, NULL, ENOENT));
5453 
5454         if (!vd->vdev_ops->vdev_op_leaf)
5455                 return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
5456 
5457         if (ispath) {
5458                 if (strcmp(value, vd->vdev_path) != 0) {
5459                         spa_strfree(vd->vdev_path);
5460                         vd->vdev_path = spa_strdup(value);
5461                         sync = B_TRUE;
5462                 }
5463         } else {
5464                 if (vd->vdev_fru == NULL) {
5465                         vd->vdev_fru = spa_strdup(value);
5466                         sync = B_TRUE;
5467                 } else if (strcmp(value, vd->vdev_fru) != 0) {
5468                         spa_strfree(vd->vdev_fru);
5469                         vd->vdev_fru = spa_strdup(value);
5470                         sync = B_TRUE;
5471                 }
5472         }
5473 
5474         return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
5475 }
5476 
5477 int
5478 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
5479 {
5480         return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
5481 }
5482 
5483 int
5484 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
5485 {
5486         return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
5487 }
5488 
5489 /*
5490  * ==========================================================================
5491  * SPA Scanning
5492  * ==========================================================================
5493  */
5494 
5495 int
5496 spa_scan_stop(spa_t *spa)
5497 {
5498         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5499         if (dsl_scan_resilvering(spa->spa_dsl_pool))
5500                 return (SET_ERROR(EBUSY));
5501         return (dsl_scan_cancel(spa->spa_dsl_pool));
5502 }
5503 
5504 int
5505 spa_scan(spa_t *spa, pool_scan_func_t func)
5506 {
5507         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5508 
5509         if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
5510                 return (SET_ERROR(ENOTSUP));
5511 
5512         /*
5513          * If a resilver was requested, but there is no DTL on a
5514          * writeable leaf device, we have nothing to do.
5515          */
5516         if (func == POOL_SCAN_RESILVER &&
5517             !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
5518                 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
5519                 return (0);
5520         }
5521 
5522         return (dsl_scan(spa->spa_dsl_pool, func));
5523 }
5524 
5525 /*
5526  * ==========================================================================
5527  * SPA async task processing
5528  * ==========================================================================
5529  */
5530 
5531 static void
5532 spa_async_remove(spa_t *spa, vdev_t *vd)
5533 {
5534         if (vd->vdev_remove_wanted) {
5535                 vd->vdev_remove_wanted = B_FALSE;
5536                 vd->vdev_delayed_close = B_FALSE;
5537                 vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
5538 
5539                 /*
5540                  * We want to clear the stats, but we don't want to do a full
5541                  * vdev_clear() as that will cause us to throw away
5542                  * degraded/faulted state as well as attempt to reopen the
5543                  * device, all of which is a waste.
5544                  */
5545                 vd->vdev_stat.vs_read_errors = 0;
5546                 vd->vdev_stat.vs_write_errors = 0;
5547                 vd->vdev_stat.vs_checksum_errors = 0;
5548 
5549                 vdev_state_dirty(vd->vdev_top);
5550         }
5551 
5552         for (int c = 0; c < vd->vdev_children; c++)
5553                 spa_async_remove(spa, vd->vdev_child[c]);
5554 }
5555 
5556 static void
5557 spa_async_probe(spa_t *spa, vdev_t *vd)
5558 {
5559         if (vd->vdev_probe_wanted) {
5560                 vd->vdev_probe_wanted = B_FALSE;
5561                 vdev_reopen(vd);        /* vdev_open() does the actual probe */
5562         }
5563 
5564         for (int c = 0; c < vd->vdev_children; c++)
5565                 spa_async_probe(spa, vd->vdev_child[c]);
5566 }
5567 
5568 static void
5569 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
5570 {
5571         sysevent_id_t eid;
5572         nvlist_t *attr;
5573         char *physpath;
5574 
5575         if (!spa->spa_autoexpand)
5576                 return;
5577 
5578         for (int c = 0; c < vd->vdev_children; c++) {
5579                 vdev_t *cvd = vd->vdev_child[c];
5580                 spa_async_autoexpand(spa, cvd);
5581         }
5582 
5583         if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
5584                 return;
5585 
5586         physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
5587         (void) snprintf(physpath, MAXPATHLEN, "/devices%s", vd->vdev_physpath);
5588 
5589         VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5590         VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
5591 
5592         (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
5593             ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
5594 
5595         nvlist_free(attr);
5596         kmem_free(physpath, MAXPATHLEN);
5597 }
5598 
5599 static void
5600 spa_async_thread(spa_t *spa)
5601 {
5602         int tasks;
5603 
5604         ASSERT(spa->spa_sync_on);
5605 
5606         mutex_enter(&spa->spa_async_lock);
5607         tasks = spa->spa_async_tasks;
5608         spa->spa_async_tasks = 0;
5609         mutex_exit(&spa->spa_async_lock);
5610 
5611         /*
5612          * See if the config needs to be updated.
5613          */
5614         if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
5615                 uint64_t old_space, new_space;
5616 
5617                 mutex_enter(&spa_namespace_lock);
5618                 old_space = metaslab_class_get_space(spa_normal_class(spa));
5619                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
5620                 new_space = metaslab_class_get_space(spa_normal_class(spa));
5621                 mutex_exit(&spa_namespace_lock);
5622 
5623                 /*
5624                  * If the pool grew as a result of the config update,
5625                  * then log an internal history event.
5626                  */
5627                 if (new_space != old_space) {
5628                         spa_history_log_internal(spa, "vdev online", NULL,
5629                             "pool '%s' size: %llu(+%llu)",
5630                             spa_name(spa), new_space, new_space - old_space);
5631                 }
5632         }
5633 
5634         /*
5635          * See if any devices need to be marked REMOVED.
5636          */
5637         if (tasks & SPA_ASYNC_REMOVE) {
5638                 spa_vdev_state_enter(spa, SCL_NONE);
5639                 spa_async_remove(spa, spa->spa_root_vdev);
5640                 for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
5641                         spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
5642                 for (int i = 0; i < spa->spa_spares.sav_count; i++)
5643                         spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
5644                 (void) spa_vdev_state_exit(spa, NULL, 0);
5645         }
5646 
5647         if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
5648                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5649                 spa_async_autoexpand(spa, spa->spa_root_vdev);
5650                 spa_config_exit(spa, SCL_CONFIG, FTAG);
5651         }
5652 
5653         /*
5654          * See if any devices need to be probed.
5655          */
5656         if (tasks & SPA_ASYNC_PROBE) {
5657                 spa_vdev_state_enter(spa, SCL_NONE);
5658                 spa_async_probe(spa, spa->spa_root_vdev);
5659                 (void) spa_vdev_state_exit(spa, NULL, 0);
5660         }
5661 
5662         /*
5663          * If any devices are done replacing, detach them.
5664          */
5665         if (tasks & SPA_ASYNC_RESILVER_DONE)
5666                 spa_vdev_resilver_done(spa);
5667 
5668         /*
5669          * Kick off a resilver.
5670          */
5671         if (tasks & SPA_ASYNC_RESILVER)
5672                 dsl_resilver_restart(spa->spa_dsl_pool, 0);
5673 
5674         /*
5675          * Let the world know that we're done.
5676          */
5677         mutex_enter(&spa->spa_async_lock);
5678         spa->spa_async_thread = NULL;
5679         cv_broadcast(&spa->spa_async_cv);
5680         mutex_exit(&spa->spa_async_lock);
5681         thread_exit();
5682 }
5683 
5684 void
5685 spa_async_suspend(spa_t *spa)
5686 {
5687         mutex_enter(&spa->spa_async_lock);
5688         spa->spa_async_suspended++;
5689         while (spa->spa_async_thread != NULL)
5690                 cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
5691         mutex_exit(&spa->spa_async_lock);
5692 }
5693 
5694 void
5695 spa_async_resume(spa_t *spa)
5696 {
5697         mutex_enter(&spa->spa_async_lock);
5698         ASSERT(spa->spa_async_suspended != 0);
5699         spa->spa_async_suspended--;
5700         mutex_exit(&spa->spa_async_lock);
5701 }
5702 
5703 static boolean_t
5704 spa_async_tasks_pending(spa_t *spa)
5705 {
5706         uint_t non_config_tasks;
5707         uint_t config_task;
5708         boolean_t config_task_suspended;
5709 
5710         non_config_tasks = spa->spa_async_tasks & ~SPA_ASYNC_CONFIG_UPDATE;
5711         config_task = spa->spa_async_tasks & SPA_ASYNC_CONFIG_UPDATE;
5712         if (spa->spa_ccw_fail_time == 0) {
5713                 config_task_suspended = B_FALSE;
5714         } else {
5715                 config_task_suspended =
5716                     (gethrtime() - spa->spa_ccw_fail_time) <
5717                     (zfs_ccw_retry_interval * NANOSEC);
5718         }
5719 
5720         return (non_config_tasks || (config_task && !config_task_suspended));
5721 }
5722 
5723 static void
5724 spa_async_dispatch(spa_t *spa)
5725 {
5726         mutex_enter(&spa->spa_async_lock);
5727         if (spa_async_tasks_pending(spa) &&
5728             !spa->spa_async_suspended &&
5729             spa->spa_async_thread == NULL &&
5730             rootdir != NULL)
5731                 spa->spa_async_thread = thread_create(NULL, 0,
5732                     spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
5733         mutex_exit(&spa->spa_async_lock);
5734 }
5735 
5736 void
5737 spa_async_request(spa_t *spa, int task)
5738 {
5739         zfs_dbgmsg("spa=%s async request task=%u", spa->spa_name, task);
5740         mutex_enter(&spa->spa_async_lock);
5741         spa->spa_async_tasks |= task;
5742         mutex_exit(&spa->spa_async_lock);
5743 }
5744 
5745 /*
5746  * ==========================================================================
5747  * SPA syncing routines
5748  * ==========================================================================
5749  */
5750 
5751 static int
5752 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5753 {
5754         bpobj_t *bpo = arg;
5755         bpobj_enqueue(bpo, bp, tx);
5756         return (0);
5757 }
5758 
5759 static int
5760 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5761 {
5762         zio_t *zio = arg;
5763 
5764         zio_nowait(zio_free_sync(zio, zio->io_spa, dmu_tx_get_txg(tx), bp,
5765             zio->io_flags));
5766         return (0);
5767 }
5768 
5769 /*
5770  * Note: this simple function is not inlined to make it easier to dtrace the
5771  * amount of time spent syncing frees.
5772  */
5773 static void
5774 spa_sync_frees(spa_t *spa, bplist_t *bpl, dmu_tx_t *tx)
5775 {
5776         zio_t *zio = zio_root(spa, NULL, NULL, 0);
5777         bplist_iterate(bpl, spa_free_sync_cb, zio, tx);
5778         VERIFY(zio_wait(zio) == 0);
5779 }
5780 
5781 /*
5782  * Note: this simple function is not inlined to make it easier to dtrace the
5783  * amount of time spent syncing deferred frees.
5784  */
5785 static void
5786 spa_sync_deferred_frees(spa_t *spa, dmu_tx_t *tx)
5787 {
5788         zio_t *zio = zio_root(spa, NULL, NULL, 0);
5789         VERIFY3U(bpobj_iterate(&spa->spa_deferred_bpobj,
5790             spa_free_sync_cb, zio, tx), ==, 0);
5791         VERIFY0(zio_wait(zio));
5792 }
5793 
5794 
5795 static void
5796 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
5797 {
5798         char *packed = NULL;
5799         size_t bufsize;
5800         size_t nvsize = 0;
5801         dmu_buf_t *db;
5802 
5803         VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
5804 
5805         /*
5806          * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
5807          * information.  This avoids the dmu_buf_will_dirty() path and
5808          * saves us a pre-read to get data we don't actually care about.
5809          */
5810         bufsize = P2ROUNDUP((uint64_t)nvsize, SPA_CONFIG_BLOCKSIZE);
5811         packed = kmem_alloc(bufsize, KM_SLEEP);
5812 
5813         VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
5814             KM_SLEEP) == 0);
5815         bzero(packed + nvsize, bufsize - nvsize);
5816 
5817         dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
5818 
5819         kmem_free(packed, bufsize);
5820 
5821         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
5822         dmu_buf_will_dirty(db, tx);
5823         *(uint64_t *)db->db_data = nvsize;
5824         dmu_buf_rele(db, FTAG);
5825 }
5826 
5827 static void
5828 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
5829     const char *config, const char *entry)
5830 {
5831         nvlist_t *nvroot;
5832         nvlist_t **list;
5833         int i;
5834 
5835         if (!sav->sav_sync)
5836                 return;
5837 
5838         /*
5839          * Update the MOS nvlist describing the list of available devices.
5840          * spa_validate_aux() will have already made sure this nvlist is
5841          * valid and the vdevs are labeled appropriately.
5842          */
5843         if (sav->sav_object == 0) {
5844                 sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
5845                     DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
5846                     sizeof (uint64_t), tx);
5847                 VERIFY(zap_update(spa->spa_meta_objset,
5848                     DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
5849                     &sav->sav_object, tx) == 0);
5850         }
5851 
5852         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5853         if (sav->sav_count == 0) {
5854                 VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
5855         } else {
5856                 list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
5857                 for (i = 0; i < sav->sav_count; i++)
5858                         list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
5859                             B_FALSE, VDEV_CONFIG_L2CACHE);
5860                 VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
5861                     sav->sav_count) == 0);
5862                 for (i = 0; i < sav->sav_count; i++)
5863                         nvlist_free(list[i]);
5864                 kmem_free(list, sav->sav_count * sizeof (void *));
5865         }
5866 
5867         spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
5868         nvlist_free(nvroot);
5869 
5870         sav->sav_sync = B_FALSE;
5871 }
5872 
5873 static void
5874 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
5875 {
5876         nvlist_t *config;
5877 
5878         if (list_is_empty(&spa->spa_config_dirty_list))
5879                 return;
5880 
5881         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5882 
5883         config = spa_config_generate(spa, spa->spa_root_vdev,
5884             dmu_tx_get_txg(tx), B_FALSE);
5885 
5886         /*
5887          * If we're upgrading the spa version then make sure that
5888          * the config object gets updated with the correct version.
5889          */
5890         if (spa->spa_ubsync.ub_version < spa->spa_uberblock.ub_version)
5891                 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
5892                     spa->spa_uberblock.ub_version);
5893 
5894         spa_config_exit(spa, SCL_STATE, FTAG);
5895 
5896         if (spa->spa_config_syncing)
5897                 nvlist_free(spa->spa_config_syncing);
5898         spa->spa_config_syncing = config;
5899 
5900         spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
5901 }
5902 
5903 static void
5904 spa_sync_version(void *arg, dmu_tx_t *tx)
5905 {
5906         uint64_t *versionp = arg;
5907         uint64_t version = *versionp;
5908         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5909 
5910         /*
5911          * Setting the version is special cased when first creating the pool.
5912          */
5913         ASSERT(tx->tx_txg != TXG_INITIAL);
5914 
5915         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
5916         ASSERT(version >= spa_version(spa));
5917 
5918         spa->spa_uberblock.ub_version = version;
5919         vdev_config_dirty(spa->spa_root_vdev);
5920         spa_history_log_internal(spa, "set", tx, "version=%lld", version);
5921 }
5922 
5923 /*
5924  * Set zpool properties.
5925  */
5926 static void
5927 spa_sync_props(void *arg, dmu_tx_t *tx)
5928 {
5929         nvlist_t *nvp = arg;
5930         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5931         objset_t *mos = spa->spa_meta_objset;
5932         nvpair_t *elem = NULL;
5933 
5934         mutex_enter(&spa->spa_props_lock);
5935 
5936         while ((elem = nvlist_next_nvpair(nvp, elem))) {
5937                 uint64_t intval;
5938                 char *strval, *fname;
5939                 zpool_prop_t prop;
5940                 const char *propname;
5941                 zprop_type_t proptype;
5942                 spa_feature_t fid;
5943 
5944                 switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
5945                 case ZPROP_INVAL:
5946                         /*
5947                          * We checked this earlier in spa_prop_validate().
5948                          */
5949                         ASSERT(zpool_prop_feature(nvpair_name(elem)));
5950 
5951                         fname = strchr(nvpair_name(elem), '@') + 1;
5952                         VERIFY0(zfeature_lookup_name(fname, &fid));
5953 
5954                         spa_feature_enable(spa, fid, tx);
5955                         spa_history_log_internal(spa, "set", tx,
5956                             "%s=enabled", nvpair_name(elem));
5957                         break;
5958 
5959                 case ZPOOL_PROP_VERSION:
5960                         intval = fnvpair_value_uint64(elem);
5961                         /*
5962                          * The version is synced seperatly before other
5963                          * properties and should be correct by now.
5964                          */
5965                         ASSERT3U(spa_version(spa), >=, intval);
5966                         break;
5967 
5968                 case ZPOOL_PROP_ALTROOT:
5969                         /*
5970                          * 'altroot' is a non-persistent property. It should
5971                          * have been set temporarily at creation or import time.
5972                          */
5973                         ASSERT(spa->spa_root != NULL);
5974                         break;
5975 
5976                 case ZPOOL_PROP_READONLY:
5977                 case ZPOOL_PROP_CACHEFILE:
5978                         /*
5979                          * 'readonly' and 'cachefile' are also non-persisitent
5980                          * properties.
5981                          */
5982                         break;
5983                 case ZPOOL_PROP_COMMENT:
5984                         strval = fnvpair_value_string(elem);
5985                         if (spa->spa_comment != NULL)
5986                                 spa_strfree(spa->spa_comment);
5987                         spa->spa_comment = spa_strdup(strval);
5988                         /*
5989                          * We need to dirty the configuration on all the vdevs
5990                          * so that their labels get updated.  It's unnecessary
5991                          * to do this for pool creation since the vdev's
5992                          * configuratoin has already been dirtied.
5993                          */
5994                         if (tx->tx_txg != TXG_INITIAL)
5995                                 vdev_config_dirty(spa->spa_root_vdev);
5996                         spa_history_log_internal(spa, "set", tx,
5997                             "%s=%s", nvpair_name(elem), strval);
5998                         break;
5999                 default:
6000                         /*
6001                          * Set pool property values in the poolprops mos object.
6002                          */
6003                         if (spa->spa_pool_props_object == 0) {
6004                                 spa->spa_pool_props_object =
6005                                     zap_create_link(mos, DMU_OT_POOL_PROPS,
6006                                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
6007                                     tx);
6008                         }
6009 
6010                         /* normalize the property name */
6011                         propname = zpool_prop_to_name(prop);
6012                         proptype = zpool_prop_get_type(prop);
6013 
6014                         if (nvpair_type(elem) == DATA_TYPE_STRING) {
6015                                 ASSERT(proptype == PROP_TYPE_STRING);
6016                                 strval = fnvpair_value_string(elem);
6017                                 VERIFY0(zap_update(mos,
6018                                     spa->spa_pool_props_object, propname,
6019                                     1, strlen(strval) + 1, strval, tx));
6020                                 spa_history_log_internal(spa, "set", tx,
6021                                     "%s=%s", nvpair_name(elem), strval);
6022                         } else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
6023                                 intval = fnvpair_value_uint64(elem);
6024 
6025                                 if (proptype == PROP_TYPE_INDEX) {
6026                                         const char *unused;
6027                                         VERIFY0(zpool_prop_index_to_string(
6028                                             prop, intval, &unused));
6029                                 }
6030                                 VERIFY0(zap_update(mos,
6031                                     spa->spa_pool_props_object, propname,
6032                                     8, 1, &intval, tx));
6033                                 spa_history_log_internal(spa, "set", tx,
6034                                     "%s=%lld", nvpair_name(elem), intval);
6035                         } else {
6036                                 ASSERT(0); /* not allowed */
6037                         }
6038 
6039                         switch (prop) {
6040                         case ZPOOL_PROP_DELEGATION:
6041                                 spa->spa_delegation = intval;
6042                                 break;
6043                         case ZPOOL_PROP_BOOTFS:
6044                                 spa->spa_bootfs = intval;
6045                                 break;
6046                         case ZPOOL_PROP_FAILUREMODE:
6047                                 spa->spa_failmode = intval;
6048                                 break;
6049                         case ZPOOL_PROP_AUTOEXPAND:
6050                                 spa->spa_autoexpand = intval;
6051                                 if (tx->tx_txg != TXG_INITIAL)
6052                                         spa_async_request(spa,
6053                                             SPA_ASYNC_AUTOEXPAND);
6054                                 break;
6055                         case ZPOOL_PROP_DEDUPDITTO:
6056                                 spa->spa_dedup_ditto = intval;
6057                                 break;
6058                         default:
6059                                 break;
6060                         }
6061                 }
6062 
6063         }
6064 
6065         mutex_exit(&spa->spa_props_lock);
6066 }
6067 
6068 /*
6069  * Perform one-time upgrade on-disk changes.  spa_version() does not
6070  * reflect the new version this txg, so there must be no changes this
6071  * txg to anything that the upgrade code depends on after it executes.
6072  * Therefore this must be called after dsl_pool_sync() does the sync
6073  * tasks.
6074  */
6075 static void
6076 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
6077 {
6078         dsl_pool_t *dp = spa->spa_dsl_pool;
6079 
6080         ASSERT(spa->spa_sync_pass == 1);
6081 
6082         rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
6083 
6084         if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
6085             spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
6086                 dsl_pool_create_origin(dp, tx);
6087 
6088                 /* Keeping the origin open increases spa_minref */
6089                 spa->spa_minref += 3;
6090         }
6091 
6092         if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
6093             spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
6094                 dsl_pool_upgrade_clones(dp, tx);
6095         }
6096 
6097         if (spa->spa_ubsync.ub_version < SPA_VERSION_DIR_CLONES &&
6098             spa->spa_uberblock.ub_version >= SPA_VERSION_DIR_CLONES) {
6099                 dsl_pool_upgrade_dir_clones(dp, tx);
6100 
6101                 /* Keeping the freedir open increases spa_minref */
6102                 spa->spa_minref += 3;
6103         }
6104 
6105         if (spa->spa_ubsync.ub_version < SPA_VERSION_FEATURES &&
6106             spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
6107                 spa_feature_create_zap_objects(spa, tx);
6108         }
6109         rrw_exit(&dp->dp_config_rwlock, FTAG);
6110 }
6111 
6112 /*
6113  * Sync the specified transaction group.  New blocks may be dirtied as
6114  * part of the process, so we iterate until it converges.
6115  */
6116 void
6117 spa_sync(spa_t *spa, uint64_t txg)
6118 {
6119         dsl_pool_t *dp = spa->spa_dsl_pool;
6120         objset_t *mos = spa->spa_meta_objset;
6121         bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
6122         vdev_t *rvd = spa->spa_root_vdev;
6123         vdev_t *vd;
6124         dmu_tx_t *tx;
6125         int error;
6126 
6127         VERIFY(spa_writeable(spa));
6128 
6129         /*
6130          * Lock out configuration changes.
6131          */
6132         spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
6133 
6134         spa->spa_syncing_txg = txg;
6135         spa->spa_sync_pass = 0;
6136 
6137         /*
6138          * If there are any pending vdev state changes, convert them
6139          * into config changes that go out with this transaction group.
6140          */
6141         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6142         while (list_head(&spa->spa_state_dirty_list) != NULL) {
6143                 /*
6144                  * We need the write lock here because, for aux vdevs,
6145                  * calling vdev_config_dirty() modifies sav_config.
6146                  * This is ugly and will become unnecessary when we
6147                  * eliminate the aux vdev wart by integrating all vdevs
6148                  * into the root vdev tree.
6149                  */
6150                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6151                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
6152                 while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
6153                         vdev_state_clean(vd);
6154                         vdev_config_dirty(vd);
6155                 }
6156                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6157                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
6158         }
6159         spa_config_exit(spa, SCL_STATE, FTAG);
6160 
6161         tx = dmu_tx_create_assigned(dp, txg);
6162 
6163         spa->spa_sync_starttime = gethrtime();
6164         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid,
6165             spa->spa_sync_starttime + spa->spa_deadman_synctime));
6166 
6167         /*
6168          * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
6169          * set spa_deflate if we have no raid-z vdevs.
6170          */
6171         if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
6172             spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
6173                 int i;
6174 
6175                 for (i = 0; i < rvd->vdev_children; i++) {
6176                         vd = rvd->vdev_child[i];
6177                         if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
6178                                 break;
6179                 }
6180                 if (i == rvd->vdev_children) {
6181                         spa->spa_deflate = TRUE;
6182                         VERIFY(0 == zap_add(spa->spa_meta_objset,
6183                             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
6184                             sizeof (uint64_t), 1, &spa->spa_deflate, tx));
6185                 }
6186         }
6187 
6188         /*
6189          * If anything has changed in this txg, or if someone is waiting
6190          * for this txg to sync (eg, spa_vdev_remove()), push the
6191          * deferred frees from the previous txg.  If not, leave them
6192          * alone so that we don't generate work on an otherwise idle
6193          * system.
6194          */
6195         if (!txg_list_empty(&dp->dp_dirty_datasets, txg) ||
6196             !txg_list_empty(&dp->dp_dirty_dirs, txg) ||
6197             !txg_list_empty(&dp->dp_sync_tasks, txg) ||
6198             ((dsl_scan_active(dp->dp_scan) ||
6199             txg_sync_waiting(dp)) && !spa_shutting_down(spa))) {
6200                 spa_sync_deferred_frees(spa, tx);
6201         }
6202 
6203         /*
6204          * Iterate to convergence.
6205          */
6206         do {
6207                 int pass = ++spa->spa_sync_pass;
6208 
6209                 spa_sync_config_object(spa, tx);
6210                 spa_sync_aux_dev(spa, &spa->spa_spares, tx,
6211                     ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
6212                 spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
6213                     ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
6214                 spa_errlog_sync(spa, txg);
6215                 dsl_pool_sync(dp, txg);
6216 
6217                 if (pass < zfs_sync_pass_deferred_free) {
6218                         spa_sync_frees(spa, free_bpl, tx);
6219                 } else {
6220                         bplist_iterate(free_bpl, bpobj_enqueue_cb,
6221                             &spa->spa_deferred_bpobj, tx);
6222                 }
6223 
6224                 ddt_sync(spa, txg);
6225                 dsl_scan_sync(dp, tx);
6226 
6227                 while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
6228                         vdev_sync(vd, txg);
6229 
6230                 if (pass == 1)
6231                         spa_sync_upgrades(spa, tx);
6232 
6233         } while (dmu_objset_is_dirty(mos, txg));
6234 
6235         /*
6236          * Rewrite the vdev configuration (which includes the uberblock)
6237          * to commit the transaction group.
6238          *
6239          * If there are no dirty vdevs, we sync the uberblock to a few
6240          * random top-level vdevs that are known to be visible in the
6241          * config cache (see spa_vdev_add() for a complete description).
6242          * If there *are* dirty vdevs, sync the uberblock to all vdevs.
6243          */
6244         for (;;) {
6245                 /*
6246                  * We hold SCL_STATE to prevent vdev open/close/etc.
6247                  * while we're attempting to write the vdev labels.
6248                  */
6249                 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6250 
6251                 if (list_is_empty(&spa->spa_config_dirty_list)) {
6252                         vdev_t *svd[SPA_DVAS_PER_BP];
6253                         int svdcount = 0;
6254                         int children = rvd->vdev_children;
6255                         int c0 = spa_get_random(children);
6256 
6257                         for (int c = 0; c < children; c++) {
6258                                 vd = rvd->vdev_child[(c0 + c) % children];
6259                                 if (vd->vdev_ms_array == 0 || vd->vdev_islog)
6260                                         continue;
6261                                 svd[svdcount++] = vd;
6262                                 if (svdcount == SPA_DVAS_PER_BP)
6263                                         break;
6264                         }
6265                         error = vdev_config_sync(svd, svdcount, txg, B_FALSE);
6266                         if (error != 0)
6267                                 error = vdev_config_sync(svd, svdcount, txg,
6268                                     B_TRUE);
6269                 } else {
6270                         error = vdev_config_sync(rvd->vdev_child,
6271                             rvd->vdev_children, txg, B_FALSE);
6272                         if (error != 0)
6273                                 error = vdev_config_sync(rvd->vdev_child,
6274                                     rvd->vdev_children, txg, B_TRUE);
6275                 }
6276 
6277                 if (error == 0)
6278                         spa->spa_last_synced_guid = rvd->vdev_guid;
6279 
6280                 spa_config_exit(spa, SCL_STATE, FTAG);
6281 
6282                 if (error == 0)
6283                         break;
6284                 zio_suspend(spa, NULL);
6285                 zio_resume_wait(spa);
6286         }
6287         dmu_tx_commit(tx);
6288 
6289         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
6290 
6291         /*
6292          * Clear the dirty config list.
6293          */
6294         while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
6295                 vdev_config_clean(vd);
6296 
6297         /*
6298          * Now that the new config has synced transactionally,
6299          * let it become visible to the config cache.
6300          */
6301         if (spa->spa_config_syncing != NULL) {
6302                 spa_config_set(spa, spa->spa_config_syncing);
6303                 spa->spa_config_txg = txg;
6304                 spa->spa_config_syncing = NULL;
6305         }
6306 
6307         spa->spa_ubsync = spa->spa_uberblock;
6308 
6309         dsl_pool_sync_done(dp, txg);
6310 
6311         /*
6312          * Update usable space statistics.
6313          */
6314         while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
6315                 vdev_sync_done(vd, txg);
6316 
6317         spa_update_dspace(spa);
6318 
6319         /*
6320          * It had better be the case that we didn't dirty anything
6321          * since vdev_config_sync().
6322          */
6323         ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
6324         ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
6325         ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
6326 
6327         spa->spa_sync_pass = 0;
6328 
6329         spa_config_exit(spa, SCL_CONFIG, FTAG);
6330 
6331         spa_handle_ignored_writes(spa);
6332 
6333         /*
6334          * If any async tasks have been requested, kick them off.
6335          */
6336         spa_async_dispatch(spa);
6337 }
6338 
6339 /*
6340  * Sync all pools.  We don't want to hold the namespace lock across these
6341  * operations, so we take a reference on the spa_t and drop the lock during the
6342  * sync.
6343  */
6344 void
6345 spa_sync_allpools(void)
6346 {
6347         spa_t *spa = NULL;
6348         mutex_enter(&spa_namespace_lock);
6349         while ((spa = spa_next(spa)) != NULL) {
6350                 if (spa_state(spa) != POOL_STATE_ACTIVE ||
6351                     !spa_writeable(spa) || spa_suspended(spa))
6352                         continue;
6353                 spa_open_ref(spa, FTAG);
6354                 mutex_exit(&spa_namespace_lock);
6355                 txg_wait_synced(spa_get_dsl(spa), 0);
6356                 mutex_enter(&spa_namespace_lock);
6357                 spa_close(spa, FTAG);
6358         }
6359         mutex_exit(&spa_namespace_lock);
6360 }
6361 
6362 /*
6363  * ==========================================================================
6364  * Miscellaneous routines
6365  * ==========================================================================
6366  */
6367 
6368 /*
6369  * Remove all pools in the system.
6370  */
6371 void
6372 spa_evict_all(void)
6373 {
6374         spa_t *spa;
6375 
6376         /*
6377          * Remove all cached state.  All pools should be closed now,
6378          * so every spa in the AVL tree should be unreferenced.
6379          */
6380         mutex_enter(&spa_namespace_lock);
6381         while ((spa = spa_next(NULL)) != NULL) {
6382                 /*
6383                  * Stop async tasks.  The async thread may need to detach
6384                  * a device that's been replaced, which requires grabbing
6385                  * spa_namespace_lock, so we must drop it here.
6386                  */
6387                 spa_open_ref(spa, FTAG);
6388                 mutex_exit(&spa_namespace_lock);
6389                 spa_async_suspend(spa);
6390                 mutex_enter(&spa_namespace_lock);
6391                 spa_close(spa, FTAG);
6392 
6393                 if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
6394                         spa_unload(spa);
6395                         spa_deactivate(spa);
6396                 }
6397                 spa_remove(spa);
6398         }
6399         mutex_exit(&spa_namespace_lock);
6400 }
6401 
6402 vdev_t *
6403 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
6404 {
6405         vdev_t *vd;
6406         int i;
6407 
6408         if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
6409                 return (vd);
6410 
6411         if (aux) {
6412                 for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
6413                         vd = spa->spa_l2cache.sav_vdevs[i];
6414                         if (vd->vdev_guid == guid)
6415                                 return (vd);
6416                 }
6417 
6418                 for (i = 0; i < spa->spa_spares.sav_count; i++) {
6419                         vd = spa->spa_spares.sav_vdevs[i];
6420                         if (vd->vdev_guid == guid)
6421                                 return (vd);
6422                 }
6423         }
6424 
6425         return (NULL);
6426 }
6427 
6428 void
6429 spa_upgrade(spa_t *spa, uint64_t version)
6430 {
6431         ASSERT(spa_writeable(spa));
6432 
6433         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6434 
6435         /*
6436          * This should only be called for a non-faulted pool, and since a
6437          * future version would result in an unopenable pool, this shouldn't be
6438          * possible.
6439          */
6440         ASSERT(SPA_VERSION_IS_SUPPORTED(spa->spa_uberblock.ub_version));
6441         ASSERT3U(version, >=, spa->spa_uberblock.ub_version);
6442 
6443         spa->spa_uberblock.ub_version = version;
6444         vdev_config_dirty(spa->spa_root_vdev);
6445 
6446         spa_config_exit(spa, SCL_ALL, FTAG);
6447 
6448         txg_wait_synced(spa_get_dsl(spa), 0);
6449 }
6450 
6451 boolean_t
6452 spa_has_spare(spa_t *spa, uint64_t guid)
6453 {
6454         int i;
6455         uint64_t spareguid;
6456         spa_aux_vdev_t *sav = &spa->spa_spares;
6457 
6458         for (i = 0; i < sav->sav_count; i++)
6459                 if (sav->sav_vdevs[i]->vdev_guid == guid)
6460                         return (B_TRUE);
6461 
6462         for (i = 0; i < sav->sav_npending; i++) {
6463                 if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
6464                     &spareguid) == 0 && spareguid == guid)
6465                         return (B_TRUE);
6466         }
6467 
6468         return (B_FALSE);
6469 }
6470 
6471 /*
6472  * Check if a pool has an active shared spare device.
6473  * Note: reference count of an active spare is 2, as a spare and as a replace
6474  */
6475 static boolean_t
6476 spa_has_active_shared_spare(spa_t *spa)
6477 {
6478         int i, refcnt;
6479         uint64_t pool;
6480         spa_aux_vdev_t *sav = &spa->spa_spares;
6481 
6482         for (i = 0; i < sav->sav_count; i++) {
6483                 if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
6484                     &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
6485                     refcnt > 2)
6486                         return (B_TRUE);
6487         }
6488 
6489         return (B_FALSE);
6490 }
6491 
6492 /*
6493  * Post a sysevent corresponding to the given event.  The 'name' must be one of
6494  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
6495  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
6496  * in the userland libzpool, as we don't want consumers to misinterpret ztest
6497  * or zdb as real changes.
6498  */
6499 void
6500 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
6501 {
6502 #ifdef _KERNEL
6503         sysevent_t              *ev;
6504         sysevent_attr_list_t    *attr = NULL;
6505         sysevent_value_t        value;
6506         sysevent_id_t           eid;
6507 
6508         ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
6509             SE_SLEEP);
6510 
6511         value.value_type = SE_DATA_TYPE_STRING;
6512         value.value.sv_string = spa_name(spa);
6513         if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
6514                 goto done;
6515 
6516         value.value_type = SE_DATA_TYPE_UINT64;
6517         value.value.sv_uint64 = spa_guid(spa);
6518         if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
6519                 goto done;
6520 
6521         if (vd) {
6522                 value.value_type = SE_DATA_TYPE_UINT64;
6523                 value.value.sv_uint64 = vd->vdev_guid;
6524                 if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
6525                     SE_SLEEP) != 0)
6526                         goto done;
6527 
6528                 if (vd->vdev_path) {
6529                         value.value_type = SE_DATA_TYPE_STRING;
6530                         value.value.sv_string = vd->vdev_path;
6531                         if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
6532                             &value, SE_SLEEP) != 0)
6533                                 goto done;
6534                 }
6535         }
6536 
6537         if (sysevent_attach_attributes(ev, attr) != 0)
6538                 goto done;
6539         attr = NULL;
6540 
6541         (void) log_sysevent(ev, SE_SLEEP, &eid);
6542 
6543 done:
6544         if (attr)
6545                 sysevent_free_attr(attr);
6546         sysevent_free(ev);
6547 #endif
6548 }