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 (c) 2013, 2014, Nexenta Systems, Inc.  All rights reserved.
  26  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  27  */
  28 
  29 /*
  30  * SPA: Storage Pool Allocator
  31  *
  32  * This file contains all the routines used when modifying on-disk SPA state.
  33  * This includes opening, importing, destroying, exporting a pool, and syncing a
  34  * pool.
  35  */
  36 
  37 #include <sys/zfs_context.h>
  38 #include <sys/fm/fs/zfs.h>
  39 #include <sys/spa_impl.h>
  40 #include <sys/zio.h>
  41 #include <sys/zio_checksum.h>
  42 #include <sys/dmu.h>
  43 #include <sys/dmu_tx.h>
  44 #include <sys/zap.h>
  45 #include <sys/zil.h>
  46 #include <sys/ddt.h>
  47 #include <sys/vdev_impl.h>
  48 #include <sys/metaslab.h>
  49 #include <sys/metaslab_impl.h>
  50 #include <sys/uberblock_impl.h>
  51 #include <sys/txg.h>
  52 #include <sys/avl.h>
  53 #include <sys/dmu_traverse.h>
  54 #include <sys/dmu_objset.h>
  55 #include <sys/unique.h>
  56 #include <sys/dsl_pool.h>
  57 #include <sys/dsl_dataset.h>
  58 #include <sys/dsl_dir.h>
  59 #include <sys/dsl_prop.h>
  60 #include <sys/dsl_synctask.h>
  61 #include <sys/fs/zfs.h>
  62 #include <sys/arc.h>
  63 #include <sys/callb.h>
  64 #include <sys/systeminfo.h>
  65 #include <sys/spa_boot.h>
  66 #include <sys/zfs_ioctl.h>
  67 #include <sys/dsl_scan.h>
  68 #include <sys/zfeature.h>
  69 #include <sys/dsl_destroy.h>
  70 
  71 #ifdef  _KERNEL
  72 #include <sys/bootprops.h>
  73 #include <sys/callb.h>
  74 #include <sys/cpupart.h>
  75 #include <sys/pool.h>
  76 #include <sys/sysdc.h>
  77 #include <sys/zone.h>
  78 #endif  /* _KERNEL */
  79 
  80 #include "zfs_prop.h"
  81 #include "zfs_comutil.h"
  82 
  83 /*
  84  * The interval, in seconds, at which failed configuration cache file writes
  85  * should be retried.
  86  */
  87 static int zfs_ccw_retry_interval = 300;
  88 
  89 typedef enum zti_modes {
  90         ZTI_MODE_FIXED,                 /* value is # of threads (min 1) */
  91         ZTI_MODE_BATCH,                 /* cpu-intensive; value is ignored */
  92         ZTI_MODE_NULL,                  /* don't create a taskq */
  93         ZTI_NMODES
  94 } zti_modes_t;
  95 
  96 #define ZTI_P(n, q)     { ZTI_MODE_FIXED, (n), (q) }
  97 #define ZTI_BATCH       { ZTI_MODE_BATCH, 0, 1 }
  98 #define ZTI_NULL        { ZTI_MODE_NULL, 0, 0 }
  99 
 100 #define ZTI_N(n)        ZTI_P(n, 1)
 101 #define ZTI_ONE         ZTI_N(1)
 102 
 103 typedef struct zio_taskq_info {
 104         zti_modes_t zti_mode;
 105         uint_t zti_value;
 106         uint_t zti_count;
 107 } zio_taskq_info_t;
 108 
 109 static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
 110         "issue", "issue_high", "intr", "intr_high"
 111 };
 112 
 113 /*
 114  * This table defines the taskq settings for each ZFS I/O type. When
 115  * initializing a pool, we use this table to create an appropriately sized
 116  * taskq. Some operations are low volume and therefore have a small, static
 117  * number of threads assigned to their taskqs using the ZTI_N(#) or ZTI_ONE
 118  * macros. Other operations process a large amount of data; the ZTI_BATCH
 119  * macro causes us to create a taskq oriented for throughput. Some operations
 120  * are so high frequency and short-lived that the taskq itself can become a a
 121  * point of lock contention. The ZTI_P(#, #) macro indicates that we need an
 122  * additional degree of parallelism specified by the number of threads per-
 123  * taskq and the number of taskqs; when dispatching an event in this case, the
 124  * particular taskq is chosen at random.
 125  *
 126  * The different taskq priorities are to handle the different contexts (issue
 127  * and interrupt) and then to reserve threads for ZIO_PRIORITY_NOW I/Os that
 128  * need to be handled with minimum delay.
 129  */
 130 const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
 131         /* ISSUE        ISSUE_HIGH      INTR            INTR_HIGH */
 132         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* NULL */
 133         { ZTI_N(8),     ZTI_NULL,       ZTI_P(12, 8),   ZTI_NULL }, /* READ */
 134         { ZTI_BATCH,    ZTI_N(5),       ZTI_N(8),       ZTI_N(5) }, /* WRITE */
 135         { ZTI_P(12, 8), ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* FREE */
 136         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* CLAIM */
 137         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* IOCTL */
 138 };
 139 
 140 static void spa_sync_version(void *arg, dmu_tx_t *tx);
 141 static void spa_sync_props(void *arg, dmu_tx_t *tx);
 142 static boolean_t spa_has_active_shared_spare(spa_t *spa);
 143 static int spa_load_impl(spa_t *spa, uint64_t, nvlist_t *config,
 144     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
 145     char **ereport);
 146 static void spa_vdev_resilver_done(spa_t *spa);
 147 
 148 uint_t          zio_taskq_batch_pct = 75;       /* 1 thread per cpu in pset */
 149 id_t            zio_taskq_psrset_bind = PS_NONE;
 150 boolean_t       zio_taskq_sysdc = B_TRUE;       /* use SDC scheduling class */
 151 uint_t          zio_taskq_basedc = 80;          /* base duty cycle */
 152 
 153 boolean_t       spa_create_process = B_TRUE;    /* no process ==> no sysdc */
 154 extern int      zfs_sync_pass_deferred_free;
 155 
 156 /*
 157  * This (illegal) pool name is used when temporarily importing a spa_t in order
 158  * to get the vdev stats associated with the imported devices.
 159  */
 160 #define TRYIMPORT_NAME  "$import"
 161 
 162 /*
 163  * ==========================================================================
 164  * SPA properties routines
 165  * ==========================================================================
 166  */
 167 
 168 /*
 169  * Add a (source=src, propname=propval) list to an nvlist.
 170  */
 171 static void
 172 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, char *strval,
 173     uint64_t intval, zprop_source_t src)
 174 {
 175         const char *propname = zpool_prop_to_name(prop);
 176         nvlist_t *propval;
 177 
 178         VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 179         VERIFY(nvlist_add_uint64(propval, ZPROP_SOURCE, src) == 0);
 180 
 181         if (strval != NULL)
 182                 VERIFY(nvlist_add_string(propval, ZPROP_VALUE, strval) == 0);
 183         else
 184                 VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, intval) == 0);
 185 
 186         VERIFY(nvlist_add_nvlist(nvl, propname, propval) == 0);
 187         nvlist_free(propval);
 188 }
 189 
 190 /*
 191  * Get property values from the spa configuration.
 192  */
 193 static void
 194 spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
 195 {
 196         vdev_t *rvd = spa->spa_root_vdev;
 197         dsl_pool_t *pool = spa->spa_dsl_pool;
 198         uint64_t size, alloc, cap, version;
 199         zprop_source_t src = ZPROP_SRC_NONE;
 200         spa_config_dirent_t *dp;
 201         metaslab_class_t *mc = spa_normal_class(spa);
 202 
 203         ASSERT(MUTEX_HELD(&spa->spa_props_lock));
 204 
 205         if (rvd != NULL) {
 206                 alloc = metaslab_class_get_alloc(spa_normal_class(spa));
 207                 size = metaslab_class_get_space(spa_normal_class(spa));
 208                 spa_prop_add_list(*nvp, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
 209                 spa_prop_add_list(*nvp, ZPOOL_PROP_SIZE, NULL, size, src);
 210                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALLOCATED, NULL, alloc, src);
 211                 spa_prop_add_list(*nvp, ZPOOL_PROP_FREE, NULL,
 212                     size - alloc, src);
 213 
 214                 spa_prop_add_list(*nvp, ZPOOL_PROP_FRAGMENTATION, NULL,
 215                     metaslab_class_fragmentation(mc), src);
 216                 spa_prop_add_list(*nvp, ZPOOL_PROP_EXPANDSZ, NULL,
 217                     metaslab_class_expandable_space(mc), src);
 218                 spa_prop_add_list(*nvp, ZPOOL_PROP_READONLY, NULL,
 219                     (spa_mode(spa) == FREAD), src);
 220 
 221                 cap = (size == 0) ? 0 : (alloc * 100 / size);
 222                 spa_prop_add_list(*nvp, ZPOOL_PROP_CAPACITY, NULL, cap, src);
 223 
 224                 spa_prop_add_list(*nvp, ZPOOL_PROP_DEDUPRATIO, NULL,
 225                     ddt_get_pool_dedup_ratio(spa), src);
 226 
 227                 spa_prop_add_list(*nvp, ZPOOL_PROP_HEALTH, NULL,
 228                     rvd->vdev_state, src);
 229 
 230                 version = spa_version(spa);
 231                 if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION))
 232                         src = ZPROP_SRC_DEFAULT;
 233                 else
 234                         src = ZPROP_SRC_LOCAL;
 235                 spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL, version, src);
 236         }
 237 
 238         if (pool != NULL) {
 239                 /*
 240                  * The $FREE directory was introduced in SPA_VERSION_DEADLISTS,
 241                  * when opening pools before this version freedir will be NULL.
 242                  */
 243                 if (pool->dp_free_dir != NULL) {
 244                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING, NULL,
 245                             dsl_dir_phys(pool->dp_free_dir)->dd_used_bytes,
 246                             src);
 247                 } else {
 248                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING,
 249                             NULL, 0, src);
 250                 }
 251 
 252                 if (pool->dp_leak_dir != NULL) {
 253                         spa_prop_add_list(*nvp, ZPOOL_PROP_LEAKED, NULL,
 254                             dsl_dir_phys(pool->dp_leak_dir)->dd_used_bytes,
 255                             src);
 256                 } else {
 257                         spa_prop_add_list(*nvp, ZPOOL_PROP_LEAKED,
 258                             NULL, 0, src);
 259                 }
 260         }
 261 
 262         spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
 263 
 264         if (spa->spa_comment != NULL) {
 265                 spa_prop_add_list(*nvp, ZPOOL_PROP_COMMENT, spa->spa_comment,
 266                     0, ZPROP_SRC_LOCAL);
 267         }
 268 
 269         if (spa->spa_root != NULL)
 270                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
 271                     0, ZPROP_SRC_LOCAL);
 272 
 273         if (spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_BLOCKS)) {
 274                 spa_prop_add_list(*nvp, ZPOOL_PROP_MAXBLOCKSIZE, NULL,
 275                     MIN(zfs_max_recordsize, SPA_MAXBLOCKSIZE), ZPROP_SRC_NONE);
 276         } else {
 277                 spa_prop_add_list(*nvp, ZPOOL_PROP_MAXBLOCKSIZE, NULL,
 278                     SPA_OLD_MAXBLOCKSIZE, ZPROP_SRC_NONE);
 279         }
 280 
 281         if ((dp = list_head(&spa->spa_config_list)) != NULL) {
 282                 if (dp->scd_path == NULL) {
 283                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 284                             "none", 0, ZPROP_SRC_LOCAL);
 285                 } else if (strcmp(dp->scd_path, spa_config_path) != 0) {
 286                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 287                             dp->scd_path, 0, ZPROP_SRC_LOCAL);
 288                 }
 289         }
 290 }
 291 
 292 /*
 293  * Get zpool property values.
 294  */
 295 int
 296 spa_prop_get(spa_t *spa, nvlist_t **nvp)
 297 {
 298         objset_t *mos = spa->spa_meta_objset;
 299         zap_cursor_t zc;
 300         zap_attribute_t za;
 301         int err;
 302 
 303         VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 304 
 305         mutex_enter(&spa->spa_props_lock);
 306 
 307         /*
 308          * Get properties from the spa config.
 309          */
 310         spa_prop_get_config(spa, nvp);
 311 
 312         /* If no pool property object, no more prop to get. */
 313         if (mos == NULL || spa->spa_pool_props_object == 0) {
 314                 mutex_exit(&spa->spa_props_lock);
 315                 return (0);
 316         }
 317 
 318         /*
 319          * Get properties from the MOS pool property object.
 320          */
 321         for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
 322             (err = zap_cursor_retrieve(&zc, &za)) == 0;
 323             zap_cursor_advance(&zc)) {
 324                 uint64_t intval = 0;
 325                 char *strval = NULL;
 326                 zprop_source_t src = ZPROP_SRC_DEFAULT;
 327                 zpool_prop_t prop;
 328 
 329                 if ((prop = zpool_name_to_prop(za.za_name)) == ZPROP_INVAL)
 330                         continue;
 331 
 332                 switch (za.za_integer_length) {
 333                 case 8:
 334                         /* integer property */
 335                         if (za.za_first_integer !=
 336                             zpool_prop_default_numeric(prop))
 337                                 src = ZPROP_SRC_LOCAL;
 338 
 339                         if (prop == ZPOOL_PROP_BOOTFS) {
 340                                 dsl_pool_t *dp;
 341                                 dsl_dataset_t *ds = NULL;
 342 
 343                                 dp = spa_get_dsl(spa);
 344                                 dsl_pool_config_enter(dp, FTAG);
 345                                 if (err = dsl_dataset_hold_obj(dp,
 346                                     za.za_first_integer, FTAG, &ds)) {
 347                                         dsl_pool_config_exit(dp, FTAG);
 348                                         break;
 349                                 }
 350 
 351                                 strval = kmem_alloc(
 352                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1,
 353                                     KM_SLEEP);
 354                                 dsl_dataset_name(ds, strval);
 355                                 dsl_dataset_rele(ds, FTAG);
 356                                 dsl_pool_config_exit(dp, FTAG);
 357                         } else {
 358                                 strval = NULL;
 359                                 intval = za.za_first_integer;
 360                         }
 361 
 362                         spa_prop_add_list(*nvp, prop, strval, intval, src);
 363 
 364                         if (strval != NULL)
 365                                 kmem_free(strval,
 366                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1);
 367 
 368                         break;
 369 
 370                 case 1:
 371                         /* string property */
 372                         strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
 373                         err = zap_lookup(mos, spa->spa_pool_props_object,
 374                             za.za_name, 1, za.za_num_integers, strval);
 375                         if (err) {
 376                                 kmem_free(strval, za.za_num_integers);
 377                                 break;
 378                         }
 379                         spa_prop_add_list(*nvp, prop, strval, 0, src);
 380                         kmem_free(strval, za.za_num_integers);
 381                         break;
 382 
 383                 default:
 384                         break;
 385                 }
 386         }
 387         zap_cursor_fini(&zc);
 388         mutex_exit(&spa->spa_props_lock);
 389 out:
 390         if (err && err != ENOENT) {
 391                 nvlist_free(*nvp);
 392                 *nvp = NULL;
 393                 return (err);
 394         }
 395 
 396         return (0);
 397 }
 398 
 399 /*
 400  * Validate the given pool properties nvlist and modify the list
 401  * for the property values to be set.
 402  */
 403 static int
 404 spa_prop_validate(spa_t *spa, nvlist_t *props)
 405 {
 406         nvpair_t *elem;
 407         int error = 0, reset_bootfs = 0;
 408         uint64_t objnum = 0;
 409         boolean_t has_feature = B_FALSE;
 410 
 411         elem = NULL;
 412         while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
 413                 uint64_t intval;
 414                 char *strval, *slash, *check, *fname;
 415                 const char *propname = nvpair_name(elem);
 416                 zpool_prop_t prop = zpool_name_to_prop(propname);
 417 
 418                 switch (prop) {
 419                 case ZPROP_INVAL:
 420                         if (!zpool_prop_feature(propname)) {
 421                                 error = SET_ERROR(EINVAL);
 422                                 break;
 423                         }
 424 
 425                         /*
 426                          * Sanitize the input.
 427                          */
 428                         if (nvpair_type(elem) != DATA_TYPE_UINT64) {
 429                                 error = SET_ERROR(EINVAL);
 430                                 break;
 431                         }
 432 
 433                         if (nvpair_value_uint64(elem, &intval) != 0) {
 434                                 error = SET_ERROR(EINVAL);
 435                                 break;
 436                         }
 437 
 438                         if (intval != 0) {
 439                                 error = SET_ERROR(EINVAL);
 440                                 break;
 441                         }
 442 
 443                         fname = strchr(propname, '@') + 1;
 444                         if (zfeature_lookup_name(fname, NULL) != 0) {
 445                                 error = SET_ERROR(EINVAL);
 446                                 break;
 447                         }
 448 
 449                         has_feature = B_TRUE;
 450                         break;
 451 
 452                 case ZPOOL_PROP_VERSION:
 453                         error = nvpair_value_uint64(elem, &intval);
 454                         if (!error &&
 455                             (intval < spa_version(spa) ||
 456                             intval > SPA_VERSION_BEFORE_FEATURES ||
 457                             has_feature))
 458                                 error = SET_ERROR(EINVAL);
 459                         break;
 460 
 461                 case ZPOOL_PROP_DELEGATION:
 462                 case ZPOOL_PROP_AUTOREPLACE:
 463                 case ZPOOL_PROP_LISTSNAPS:
 464                 case ZPOOL_PROP_AUTOEXPAND:
 465                         error = nvpair_value_uint64(elem, &intval);
 466                         if (!error && intval > 1)
 467                                 error = SET_ERROR(EINVAL);
 468                         break;
 469 
 470                 case ZPOOL_PROP_BOOTFS:
 471                         /*
 472                          * If the pool version is less than SPA_VERSION_BOOTFS,
 473                          * or the pool is still being created (version == 0),
 474                          * the bootfs property cannot be set.
 475                          */
 476                         if (spa_version(spa) < SPA_VERSION_BOOTFS) {
 477                                 error = SET_ERROR(ENOTSUP);
 478                                 break;
 479                         }
 480 
 481                         /*
 482                          * Make sure the vdev config is bootable
 483                          */
 484                         if (!vdev_is_bootable(spa->spa_root_vdev)) {
 485                                 error = SET_ERROR(ENOTSUP);
 486                                 break;
 487                         }
 488 
 489                         reset_bootfs = 1;
 490 
 491                         error = nvpair_value_string(elem, &strval);
 492 
 493                         if (!error) {
 494                                 objset_t *os;
 495                                 uint64_t propval;
 496 
 497                                 if (strval == NULL || strval[0] == '\0') {
 498                                         objnum = zpool_prop_default_numeric(
 499                                             ZPOOL_PROP_BOOTFS);
 500                                         break;
 501                                 }
 502 
 503                                 if (error = dmu_objset_hold(strval, FTAG, &os))
 504                                         break;
 505 
 506                                 /*
 507                                  * Must be ZPL, and its property settings
 508                                  * must be supported by GRUB (compression
 509                                  * is not gzip, and large blocks are not used).
 510                                  */
 511 
 512                                 if (dmu_objset_type(os) != DMU_OST_ZFS) {
 513                                         error = SET_ERROR(ENOTSUP);
 514                                 } else if ((error =
 515                                     dsl_prop_get_int_ds(dmu_objset_ds(os),
 516                                     zfs_prop_to_name(ZFS_PROP_COMPRESSION),
 517                                     &propval)) == 0 &&
 518                                     !BOOTFS_COMPRESS_VALID(propval)) {
 519                                         error = SET_ERROR(ENOTSUP);
 520                                 } else if ((error =
 521                                     dsl_prop_get_int_ds(dmu_objset_ds(os),
 522                                     zfs_prop_to_name(ZFS_PROP_RECORDSIZE),
 523                                     &propval)) == 0 &&
 524                                     propval > SPA_OLD_MAXBLOCKSIZE) {
 525                                         error = SET_ERROR(ENOTSUP);
 526                                 } else {
 527                                         objnum = dmu_objset_id(os);
 528                                 }
 529                                 dmu_objset_rele(os, FTAG);
 530                         }
 531                         break;
 532 
 533                 case ZPOOL_PROP_FAILUREMODE:
 534                         error = nvpair_value_uint64(elem, &intval);
 535                         if (!error && (intval < ZIO_FAILURE_MODE_WAIT ||
 536                             intval > ZIO_FAILURE_MODE_PANIC))
 537                                 error = SET_ERROR(EINVAL);
 538 
 539                         /*
 540                          * This is a special case which only occurs when
 541                          * the pool has completely failed. This allows
 542                          * the user to change the in-core failmode property
 543                          * without syncing it out to disk (I/Os might
 544                          * currently be blocked). We do this by returning
 545                          * EIO to the caller (spa_prop_set) to trick it
 546                          * into thinking we encountered a property validation
 547                          * error.
 548                          */
 549                         if (!error && spa_suspended(spa)) {
 550                                 spa->spa_failmode = intval;
 551                                 error = SET_ERROR(EIO);
 552                         }
 553                         break;
 554 
 555                 case ZPOOL_PROP_CACHEFILE:
 556                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 557                                 break;
 558 
 559                         if (strval[0] == '\0')
 560                                 break;
 561 
 562                         if (strcmp(strval, "none") == 0)
 563                                 break;
 564 
 565                         if (strval[0] != '/') {
 566                                 error = SET_ERROR(EINVAL);
 567                                 break;
 568                         }
 569 
 570                         slash = strrchr(strval, '/');
 571                         ASSERT(slash != NULL);
 572 
 573                         if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
 574                             strcmp(slash, "/..") == 0)
 575                                 error = SET_ERROR(EINVAL);
 576                         break;
 577 
 578                 case ZPOOL_PROP_COMMENT:
 579                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 580                                 break;
 581                         for (check = strval; *check != '\0'; check++) {
 582                                 /*
 583                                  * The kernel doesn't have an easy isprint()
 584                                  * check.  For this kernel check, we merely
 585                                  * check ASCII apart from DEL.  Fix this if
 586                                  * there is an easy-to-use kernel isprint().
 587                                  */
 588                                 if (*check >= 0x7f) {
 589                                         error = SET_ERROR(EINVAL);
 590                                         break;
 591                                 }
 592                                 check++;
 593                         }
 594                         if (strlen(strval) > ZPROP_MAX_COMMENT)
 595                                 error = E2BIG;
 596                         break;
 597 
 598                 case ZPOOL_PROP_DEDUPDITTO:
 599                         if (spa_version(spa) < SPA_VERSION_DEDUP)
 600                                 error = SET_ERROR(ENOTSUP);
 601                         else
 602                                 error = nvpair_value_uint64(elem, &intval);
 603                         if (error == 0 &&
 604                             intval != 0 && intval < ZIO_DEDUPDITTO_MIN)
 605                                 error = SET_ERROR(EINVAL);
 606                         break;
 607                 }
 608 
 609                 if (error)
 610                         break;
 611         }
 612 
 613         if (!error && reset_bootfs) {
 614                 error = nvlist_remove(props,
 615                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
 616 
 617                 if (!error) {
 618                         error = nvlist_add_uint64(props,
 619                             zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
 620                 }
 621         }
 622 
 623         return (error);
 624 }
 625 
 626 void
 627 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
 628 {
 629         char *cachefile;
 630         spa_config_dirent_t *dp;
 631 
 632         if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
 633             &cachefile) != 0)
 634                 return;
 635 
 636         dp = kmem_alloc(sizeof (spa_config_dirent_t),
 637             KM_SLEEP);
 638 
 639         if (cachefile[0] == '\0')
 640                 dp->scd_path = spa_strdup(spa_config_path);
 641         else if (strcmp(cachefile, "none") == 0)
 642                 dp->scd_path = NULL;
 643         else
 644                 dp->scd_path = spa_strdup(cachefile);
 645 
 646         list_insert_head(&spa->spa_config_list, dp);
 647         if (need_sync)
 648                 spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
 649 }
 650 
 651 int
 652 spa_prop_set(spa_t *spa, nvlist_t *nvp)
 653 {
 654         int error;
 655         nvpair_t *elem = NULL;
 656         boolean_t need_sync = B_FALSE;
 657 
 658         if ((error = spa_prop_validate(spa, nvp)) != 0)
 659                 return (error);
 660 
 661         while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
 662                 zpool_prop_t prop = zpool_name_to_prop(nvpair_name(elem));
 663 
 664                 if (prop == ZPOOL_PROP_CACHEFILE ||
 665                     prop == ZPOOL_PROP_ALTROOT ||
 666                     prop == ZPOOL_PROP_READONLY)
 667                         continue;
 668 
 669                 if (prop == ZPOOL_PROP_VERSION || prop == ZPROP_INVAL) {
 670                         uint64_t ver;
 671 
 672                         if (prop == ZPOOL_PROP_VERSION) {
 673                                 VERIFY(nvpair_value_uint64(elem, &ver) == 0);
 674                         } else {
 675                                 ASSERT(zpool_prop_feature(nvpair_name(elem)));
 676                                 ver = SPA_VERSION_FEATURES;
 677                                 need_sync = B_TRUE;
 678                         }
 679 
 680                         /* Save time if the version is already set. */
 681                         if (ver == spa_version(spa))
 682                                 continue;
 683 
 684                         /*
 685                          * In addition to the pool directory object, we might
 686                          * create the pool properties object, the features for
 687                          * read object, the features for write object, or the
 688                          * feature descriptions object.
 689                          */
 690                         error = dsl_sync_task(spa->spa_name, NULL,
 691                             spa_sync_version, &ver,
 692                             6, ZFS_SPACE_CHECK_RESERVED);
 693                         if (error)
 694                                 return (error);
 695                         continue;
 696                 }
 697 
 698                 need_sync = B_TRUE;
 699                 break;
 700         }
 701 
 702         if (need_sync) {
 703                 return (dsl_sync_task(spa->spa_name, NULL, spa_sync_props,
 704                     nvp, 6, ZFS_SPACE_CHECK_RESERVED));
 705         }
 706 
 707         return (0);
 708 }
 709 
 710 /*
 711  * If the bootfs property value is dsobj, clear it.
 712  */
 713 void
 714 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
 715 {
 716         if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
 717                 VERIFY(zap_remove(spa->spa_meta_objset,
 718                     spa->spa_pool_props_object,
 719                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
 720                 spa->spa_bootfs = 0;
 721         }
 722 }
 723 
 724 /*ARGSUSED*/
 725 static int
 726 spa_change_guid_check(void *arg, dmu_tx_t *tx)
 727 {
 728         uint64_t *newguid = arg;
 729         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 730         vdev_t *rvd = spa->spa_root_vdev;
 731         uint64_t vdev_state;
 732 
 733         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
 734         vdev_state = rvd->vdev_state;
 735         spa_config_exit(spa, SCL_STATE, FTAG);
 736 
 737         if (vdev_state != VDEV_STATE_HEALTHY)
 738                 return (SET_ERROR(ENXIO));
 739 
 740         ASSERT3U(spa_guid(spa), !=, *newguid);
 741 
 742         return (0);
 743 }
 744 
 745 static void
 746 spa_change_guid_sync(void *arg, dmu_tx_t *tx)
 747 {
 748         uint64_t *newguid = arg;
 749         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 750         uint64_t oldguid;
 751         vdev_t *rvd = spa->spa_root_vdev;
 752 
 753         oldguid = spa_guid(spa);
 754 
 755         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
 756         rvd->vdev_guid = *newguid;
 757         rvd->vdev_guid_sum += (*newguid - oldguid);
 758         vdev_config_dirty(rvd);
 759         spa_config_exit(spa, SCL_STATE, FTAG);
 760 
 761         spa_history_log_internal(spa, "guid change", tx, "old=%llu new=%llu",
 762             oldguid, *newguid);
 763 }
 764 
 765 /*
 766  * Change the GUID for the pool.  This is done so that we can later
 767  * re-import a pool built from a clone of our own vdevs.  We will modify
 768  * the root vdev's guid, our own pool guid, and then mark all of our
 769  * vdevs dirty.  Note that we must make sure that all our vdevs are
 770  * online when we do this, or else any vdevs that weren't present
 771  * would be orphaned from our pool.  We are also going to issue a
 772  * sysevent to update any watchers.
 773  */
 774 int
 775 spa_change_guid(spa_t *spa)
 776 {
 777         int error;
 778         uint64_t guid;
 779 
 780         mutex_enter(&spa->spa_vdev_top_lock);
 781         mutex_enter(&spa_namespace_lock);
 782         guid = spa_generate_guid(NULL);
 783 
 784         error = dsl_sync_task(spa->spa_name, spa_change_guid_check,
 785             spa_change_guid_sync, &guid, 5, ZFS_SPACE_CHECK_RESERVED);
 786 
 787         if (error == 0) {
 788                 spa_config_sync(spa, B_FALSE, B_TRUE);
 789                 spa_event_notify(spa, NULL, ESC_ZFS_POOL_REGUID);
 790         }
 791 
 792         mutex_exit(&spa_namespace_lock);
 793         mutex_exit(&spa->spa_vdev_top_lock);
 794 
 795         return (error);
 796 }
 797 
 798 /*
 799  * ==========================================================================
 800  * SPA state manipulation (open/create/destroy/import/export)
 801  * ==========================================================================
 802  */
 803 
 804 static int
 805 spa_error_entry_compare(const void *a, const void *b)
 806 {
 807         spa_error_entry_t *sa = (spa_error_entry_t *)a;
 808         spa_error_entry_t *sb = (spa_error_entry_t *)b;
 809         int ret;
 810 
 811         ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
 812             sizeof (zbookmark_phys_t));
 813 
 814         if (ret < 0)
 815                 return (-1);
 816         else if (ret > 0)
 817                 return (1);
 818         else
 819                 return (0);
 820 }
 821 
 822 /*
 823  * Utility function which retrieves copies of the current logs and
 824  * re-initializes them in the process.
 825  */
 826 void
 827 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
 828 {
 829         ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
 830 
 831         bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
 832         bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));
 833 
 834         avl_create(&spa->spa_errlist_scrub,
 835             spa_error_entry_compare, sizeof (spa_error_entry_t),
 836             offsetof(spa_error_entry_t, se_avl));
 837         avl_create(&spa->spa_errlist_last,
 838             spa_error_entry_compare, sizeof (spa_error_entry_t),
 839             offsetof(spa_error_entry_t, se_avl));
 840 }
 841 
 842 static void
 843 spa_taskqs_init(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
 844 {
 845         const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
 846         enum zti_modes mode = ztip->zti_mode;
 847         uint_t value = ztip->zti_value;
 848         uint_t count = ztip->zti_count;
 849         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 850         char name[32];
 851         uint_t flags = 0;
 852         boolean_t batch = B_FALSE;
 853 
 854         if (mode == ZTI_MODE_NULL) {
 855                 tqs->stqs_count = 0;
 856                 tqs->stqs_taskq = NULL;
 857                 return;
 858         }
 859 
 860         ASSERT3U(count, >, 0);
 861 
 862         tqs->stqs_count = count;
 863         tqs->stqs_taskq = kmem_alloc(count * sizeof (taskq_t *), KM_SLEEP);
 864 
 865         switch (mode) {
 866         case ZTI_MODE_FIXED:
 867                 ASSERT3U(value, >=, 1);
 868                 value = MAX(value, 1);
 869                 break;
 870 
 871         case ZTI_MODE_BATCH:
 872                 batch = B_TRUE;
 873                 flags |= TASKQ_THREADS_CPU_PCT;
 874                 value = zio_taskq_batch_pct;
 875                 break;
 876 
 877         default:
 878                 panic("unrecognized mode for %s_%s taskq (%u:%u) in "
 879                     "spa_activate()",
 880                     zio_type_name[t], zio_taskq_types[q], mode, value);
 881                 break;
 882         }
 883 
 884         for (uint_t i = 0; i < count; i++) {
 885                 taskq_t *tq;
 886 
 887                 if (count > 1) {
 888                         (void) snprintf(name, sizeof (name), "%s_%s_%u",
 889                             zio_type_name[t], zio_taskq_types[q], i);
 890                 } else {
 891                         (void) snprintf(name, sizeof (name), "%s_%s",
 892                             zio_type_name[t], zio_taskq_types[q]);
 893                 }
 894 
 895                 if (zio_taskq_sysdc && spa->spa_proc != &p0) {
 896                         if (batch)
 897                                 flags |= TASKQ_DC_BATCH;
 898 
 899                         tq = taskq_create_sysdc(name, value, 50, INT_MAX,
 900                             spa->spa_proc, zio_taskq_basedc, flags);
 901                 } else {
 902                         pri_t pri = maxclsyspri;
 903                         /*
 904                          * The write issue taskq can be extremely CPU
 905                          * intensive.  Run it at slightly lower priority
 906                          * than the other taskqs.
 907                          */
 908                         if (t == ZIO_TYPE_WRITE && q == ZIO_TASKQ_ISSUE)
 909                                 pri--;
 910 
 911                         tq = taskq_create_proc(name, value, pri, 50,
 912                             INT_MAX, spa->spa_proc, flags);
 913                 }
 914 
 915                 tqs->stqs_taskq[i] = tq;
 916         }
 917 }
 918 
 919 static void
 920 spa_taskqs_fini(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
 921 {
 922         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 923 
 924         if (tqs->stqs_taskq == NULL) {
 925                 ASSERT0(tqs->stqs_count);
 926                 return;
 927         }
 928 
 929         for (uint_t i = 0; i < tqs->stqs_count; i++) {
 930                 ASSERT3P(tqs->stqs_taskq[i], !=, NULL);
 931                 taskq_destroy(tqs->stqs_taskq[i]);
 932         }
 933 
 934         kmem_free(tqs->stqs_taskq, tqs->stqs_count * sizeof (taskq_t *));
 935         tqs->stqs_taskq = NULL;
 936 }
 937 
 938 /*
 939  * Dispatch a task to the appropriate taskq for the ZFS I/O type and priority.
 940  * Note that a type may have multiple discrete taskqs to avoid lock contention
 941  * on the taskq itself. In that case we choose which taskq at random by using
 942  * the low bits of gethrtime().
 943  */
 944 void
 945 spa_taskq_dispatch_ent(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
 946     task_func_t *func, void *arg, uint_t flags, taskq_ent_t *ent)
 947 {
 948         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 949         taskq_t *tq;
 950 
 951         ASSERT3P(tqs->stqs_taskq, !=, NULL);
 952         ASSERT3U(tqs->stqs_count, !=, 0);
 953 
 954         if (tqs->stqs_count == 1) {
 955                 tq = tqs->stqs_taskq[0];
 956         } else {
 957                 tq = tqs->stqs_taskq[gethrtime() % tqs->stqs_count];
 958         }
 959 
 960         taskq_dispatch_ent(tq, func, arg, flags, ent);
 961 }
 962 
 963 static void
 964 spa_create_zio_taskqs(spa_t *spa)
 965 {
 966         for (int t = 0; t < ZIO_TYPES; t++) {
 967                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
 968                         spa_taskqs_init(spa, t, q);
 969                 }
 970         }
 971 }
 972 
 973 #ifdef _KERNEL
 974 static void
 975 spa_thread(void *arg)
 976 {
 977         callb_cpr_t cprinfo;
 978 
 979         spa_t *spa = arg;
 980         user_t *pu = PTOU(curproc);
 981 
 982         CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
 983             spa->spa_name);
 984 
 985         ASSERT(curproc != &p0);
 986         (void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
 987             "zpool-%s", spa->spa_name);
 988         (void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
 989 
 990         /* bind this thread to the requested psrset */
 991         if (zio_taskq_psrset_bind != PS_NONE) {
 992                 pool_lock();
 993                 mutex_enter(&cpu_lock);
 994                 mutex_enter(&pidlock);
 995                 mutex_enter(&curproc->p_lock);
 996 
 997                 if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
 998                     0, NULL, NULL) == 0)  {
 999                         curthread->t_bind_pset = zio_taskq_psrset_bind;
1000                 } else {
1001                         cmn_err(CE_WARN,
1002                             "Couldn't bind process for zfs pool \"%s\" to "
1003                             "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
1004                 }
1005 
1006                 mutex_exit(&curproc->p_lock);
1007                 mutex_exit(&pidlock);
1008                 mutex_exit(&cpu_lock);
1009                 pool_unlock();
1010         }
1011 
1012         if (zio_taskq_sysdc) {
1013                 sysdc_thread_enter(curthread, 100, 0);
1014         }
1015 
1016         spa->spa_proc = curproc;
1017         spa->spa_did = curthread->t_did;
1018 
1019         spa_create_zio_taskqs(spa);
1020 
1021         mutex_enter(&spa->spa_proc_lock);
1022         ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
1023 
1024         spa->spa_proc_state = SPA_PROC_ACTIVE;
1025         cv_broadcast(&spa->spa_proc_cv);
1026 
1027         CALLB_CPR_SAFE_BEGIN(&cprinfo);
1028         while (spa->spa_proc_state == SPA_PROC_ACTIVE)
1029                 cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1030         CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
1031 
1032         ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
1033         spa->spa_proc_state = SPA_PROC_GONE;
1034         spa->spa_proc = &p0;
1035         cv_broadcast(&spa->spa_proc_cv);
1036         CALLB_CPR_EXIT(&cprinfo);   /* drops spa_proc_lock */
1037 
1038         mutex_enter(&curproc->p_lock);
1039         lwp_exit();
1040 }
1041 #endif
1042 
1043 /*
1044  * Activate an uninitialized pool.
1045  */
1046 static void
1047 spa_activate(spa_t *spa, int mode)
1048 {
1049         ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
1050 
1051         spa->spa_state = POOL_STATE_ACTIVE;
1052         spa->spa_mode = mode;
1053 
1054         spa->spa_normal_class = metaslab_class_create(spa, zfs_metaslab_ops);
1055         spa->spa_log_class = metaslab_class_create(spa, zfs_metaslab_ops);
1056 
1057         /* Try to create a covering process */
1058         mutex_enter(&spa->spa_proc_lock);
1059         ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
1060         ASSERT(spa->spa_proc == &p0);
1061         spa->spa_did = 0;
1062 
1063         /* Only create a process if we're going to be around a while. */
1064         if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
1065                 if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
1066                     NULL, 0) == 0) {
1067                         spa->spa_proc_state = SPA_PROC_CREATED;
1068                         while (spa->spa_proc_state == SPA_PROC_CREATED) {
1069                                 cv_wait(&spa->spa_proc_cv,
1070                                     &spa->spa_proc_lock);
1071                         }
1072                         ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1073                         ASSERT(spa->spa_proc != &p0);
1074                         ASSERT(spa->spa_did != 0);
1075                 } else {
1076 #ifdef _KERNEL
1077                         cmn_err(CE_WARN,
1078                             "Couldn't create process for zfs pool \"%s\"\n",
1079                             spa->spa_name);
1080 #endif
1081                 }
1082         }
1083         mutex_exit(&spa->spa_proc_lock);
1084 
1085         /* If we didn't create a process, we need to create our taskqs. */
1086         if (spa->spa_proc == &p0) {
1087                 spa_create_zio_taskqs(spa);
1088         }
1089 
1090         list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
1091             offsetof(vdev_t, vdev_config_dirty_node));
1092         list_create(&spa->spa_evicting_os_list, sizeof (objset_t),
1093             offsetof(objset_t, os_evicting_node));
1094         list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
1095             offsetof(vdev_t, vdev_state_dirty_node));
1096 
1097         txg_list_create(&spa->spa_vdev_txg_list,
1098             offsetof(struct vdev, vdev_txg_node));
1099 
1100         avl_create(&spa->spa_errlist_scrub,
1101             spa_error_entry_compare, sizeof (spa_error_entry_t),
1102             offsetof(spa_error_entry_t, se_avl));
1103         avl_create(&spa->spa_errlist_last,
1104             spa_error_entry_compare, sizeof (spa_error_entry_t),
1105             offsetof(spa_error_entry_t, se_avl));
1106 }
1107 
1108 /*
1109  * Opposite of spa_activate().
1110  */
1111 static void
1112 spa_deactivate(spa_t *spa)
1113 {
1114         ASSERT(spa->spa_sync_on == B_FALSE);
1115         ASSERT(spa->spa_dsl_pool == NULL);
1116         ASSERT(spa->spa_root_vdev == NULL);
1117         ASSERT(spa->spa_async_zio_root == NULL);
1118         ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
1119 
1120         spa_evicting_os_wait(spa);
1121 
1122         txg_list_destroy(&spa->spa_vdev_txg_list);
1123 
1124         list_destroy(&spa->spa_config_dirty_list);
1125         list_destroy(&spa->spa_evicting_os_list);
1126         list_destroy(&spa->spa_state_dirty_list);
1127 
1128         for (int t = 0; t < ZIO_TYPES; t++) {
1129                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
1130                         spa_taskqs_fini(spa, t, q);
1131                 }
1132         }
1133 
1134         metaslab_class_destroy(spa->spa_normal_class);
1135         spa->spa_normal_class = NULL;
1136 
1137         metaslab_class_destroy(spa->spa_log_class);
1138         spa->spa_log_class = NULL;
1139 
1140         /*
1141          * If this was part of an import or the open otherwise failed, we may
1142          * still have errors left in the queues.  Empty them just in case.
1143          */
1144         spa_errlog_drain(spa);
1145 
1146         avl_destroy(&spa->spa_errlist_scrub);
1147         avl_destroy(&spa->spa_errlist_last);
1148 
1149         spa->spa_state = POOL_STATE_UNINITIALIZED;
1150 
1151         mutex_enter(&spa->spa_proc_lock);
1152         if (spa->spa_proc_state != SPA_PROC_NONE) {
1153                 ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1154                 spa->spa_proc_state = SPA_PROC_DEACTIVATE;
1155                 cv_broadcast(&spa->spa_proc_cv);
1156                 while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
1157                         ASSERT(spa->spa_proc != &p0);
1158                         cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1159                 }
1160                 ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
1161                 spa->spa_proc_state = SPA_PROC_NONE;
1162         }
1163         ASSERT(spa->spa_proc == &p0);
1164         mutex_exit(&spa->spa_proc_lock);
1165 
1166         /*
1167          * We want to make sure spa_thread() has actually exited the ZFS
1168          * module, so that the module can't be unloaded out from underneath
1169          * it.
1170          */
1171         if (spa->spa_did != 0) {
1172                 thread_join(spa->spa_did);
1173                 spa->spa_did = 0;
1174         }
1175 }
1176 
1177 /*
1178  * Verify a pool configuration, and construct the vdev tree appropriately.  This
1179  * will create all the necessary vdevs in the appropriate layout, with each vdev
1180  * in the CLOSED state.  This will prep the pool before open/creation/import.
1181  * All vdev validation is done by the vdev_alloc() routine.
1182  */
1183 static int
1184 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
1185     uint_t id, int atype)
1186 {
1187         nvlist_t **child;
1188         uint_t children;
1189         int error;
1190 
1191         if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
1192                 return (error);
1193 
1194         if ((*vdp)->vdev_ops->vdev_op_leaf)
1195                 return (0);
1196 
1197         error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
1198             &child, &children);
1199 
1200         if (error == ENOENT)
1201                 return (0);
1202 
1203         if (error) {
1204                 vdev_free(*vdp);
1205                 *vdp = NULL;
1206                 return (SET_ERROR(EINVAL));
1207         }
1208 
1209         for (int c = 0; c < children; c++) {
1210                 vdev_t *vd;
1211                 if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
1212                     atype)) != 0) {
1213                         vdev_free(*vdp);
1214                         *vdp = NULL;
1215                         return (error);
1216                 }
1217         }
1218 
1219         ASSERT(*vdp != NULL);
1220 
1221         return (0);
1222 }
1223 
1224 /*
1225  * Opposite of spa_load().
1226  */
1227 static void
1228 spa_unload(spa_t *spa)
1229 {
1230         int i;
1231 
1232         ASSERT(MUTEX_HELD(&spa_namespace_lock));
1233 
1234         /*
1235          * Stop async tasks.
1236          */
1237         spa_async_suspend(spa);
1238 
1239         /*
1240          * Stop syncing.
1241          */
1242         if (spa->spa_sync_on) {
1243                 txg_sync_stop(spa->spa_dsl_pool);
1244                 spa->spa_sync_on = B_FALSE;
1245         }
1246 
1247         /*
1248          * Wait for any outstanding async I/O to complete.
1249          */
1250         if (spa->spa_async_zio_root != NULL) {
1251                 for (int i = 0; i < max_ncpus; i++)
1252                         (void) zio_wait(spa->spa_async_zio_root[i]);
1253                 kmem_free(spa->spa_async_zio_root, max_ncpus * sizeof (void *));
1254                 spa->spa_async_zio_root = NULL;
1255         }
1256 
1257         bpobj_close(&spa->spa_deferred_bpobj);
1258 
1259         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1260 
1261         /*
1262          * Close all vdevs.
1263          */
1264         if (spa->spa_root_vdev)
1265                 vdev_free(spa->spa_root_vdev);
1266         ASSERT(spa->spa_root_vdev == NULL);
1267 
1268         /*
1269          * Close the dsl pool.
1270          */
1271         if (spa->spa_dsl_pool) {
1272                 dsl_pool_close(spa->spa_dsl_pool);
1273                 spa->spa_dsl_pool = NULL;
1274                 spa->spa_meta_objset = NULL;
1275         }
1276 
1277         ddt_unload(spa);
1278 
1279 
1280         /*
1281          * Drop and purge level 2 cache
1282          */
1283         spa_l2cache_drop(spa);
1284 
1285         for (i = 0; i < spa->spa_spares.sav_count; i++)
1286                 vdev_free(spa->spa_spares.sav_vdevs[i]);
1287         if (spa->spa_spares.sav_vdevs) {
1288                 kmem_free(spa->spa_spares.sav_vdevs,
1289                     spa->spa_spares.sav_count * sizeof (void *));
1290                 spa->spa_spares.sav_vdevs = NULL;
1291         }
1292         if (spa->spa_spares.sav_config) {
1293                 nvlist_free(spa->spa_spares.sav_config);
1294                 spa->spa_spares.sav_config = NULL;
1295         }
1296         spa->spa_spares.sav_count = 0;
1297 
1298         for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
1299                 vdev_clear_stats(spa->spa_l2cache.sav_vdevs[i]);
1300                 vdev_free(spa->spa_l2cache.sav_vdevs[i]);
1301         }
1302         if (spa->spa_l2cache.sav_vdevs) {
1303                 kmem_free(spa->spa_l2cache.sav_vdevs,
1304                     spa->spa_l2cache.sav_count * sizeof (void *));
1305                 spa->spa_l2cache.sav_vdevs = NULL;
1306         }
1307         if (spa->spa_l2cache.sav_config) {
1308                 nvlist_free(spa->spa_l2cache.sav_config);
1309                 spa->spa_l2cache.sav_config = NULL;
1310         }
1311         spa->spa_l2cache.sav_count = 0;
1312 
1313         spa->spa_async_suspended = 0;
1314 
1315         if (spa->spa_comment != NULL) {
1316                 spa_strfree(spa->spa_comment);
1317                 spa->spa_comment = NULL;
1318         }
1319 
1320         spa_config_exit(spa, SCL_ALL, FTAG);
1321 }
1322 
1323 /*
1324  * Load (or re-load) the current list of vdevs describing the active spares for
1325  * this pool.  When this is called, we have some form of basic information in
1326  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
1327  * then re-generate a more complete list including status information.
1328  */
1329 static void
1330 spa_load_spares(spa_t *spa)
1331 {
1332         nvlist_t **spares;
1333         uint_t nspares;
1334         int i;
1335         vdev_t *vd, *tvd;
1336 
1337         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1338 
1339         /*
1340          * First, close and free any existing spare vdevs.
1341          */
1342         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1343                 vd = spa->spa_spares.sav_vdevs[i];
1344 
1345                 /* Undo the call to spa_activate() below */
1346                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1347                     B_FALSE)) != NULL && tvd->vdev_isspare)
1348                         spa_spare_remove(tvd);
1349                 vdev_close(vd);
1350                 vdev_free(vd);
1351         }
1352 
1353         if (spa->spa_spares.sav_vdevs)
1354                 kmem_free(spa->spa_spares.sav_vdevs,
1355                     spa->spa_spares.sav_count * sizeof (void *));
1356 
1357         if (spa->spa_spares.sav_config == NULL)
1358                 nspares = 0;
1359         else
1360                 VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1361                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1362 
1363         spa->spa_spares.sav_count = (int)nspares;
1364         spa->spa_spares.sav_vdevs = NULL;
1365 
1366         if (nspares == 0)
1367                 return;
1368 
1369         /*
1370          * Construct the array of vdevs, opening them to get status in the
1371          * process.   For each spare, there is potentially two different vdev_t
1372          * structures associated with it: one in the list of spares (used only
1373          * for basic validation purposes) and one in the active vdev
1374          * configuration (if it's spared in).  During this phase we open and
1375          * validate each vdev on the spare list.  If the vdev also exists in the
1376          * active configuration, then we also mark this vdev as an active spare.
1377          */
1378         spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
1379             KM_SLEEP);
1380         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1381                 VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
1382                     VDEV_ALLOC_SPARE) == 0);
1383                 ASSERT(vd != NULL);
1384 
1385                 spa->spa_spares.sav_vdevs[i] = vd;
1386 
1387                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1388                     B_FALSE)) != NULL) {
1389                         if (!tvd->vdev_isspare)
1390                                 spa_spare_add(tvd);
1391 
1392                         /*
1393                          * We only mark the spare active if we were successfully
1394                          * able to load the vdev.  Otherwise, importing a pool
1395                          * with a bad active spare would result in strange
1396                          * behavior, because multiple pool would think the spare
1397                          * is actively in use.
1398                          *
1399                          * There is a vulnerability here to an equally bizarre
1400                          * circumstance, where a dead active spare is later
1401                          * brought back to life (onlined or otherwise).  Given
1402                          * the rarity of this scenario, and the extra complexity
1403                          * it adds, we ignore the possibility.
1404                          */
1405                         if (!vdev_is_dead(tvd))
1406                                 spa_spare_activate(tvd);
1407                 }
1408 
1409                 vd->vdev_top = vd;
1410                 vd->vdev_aux = &spa->spa_spares;
1411 
1412                 if (vdev_open(vd) != 0)
1413                         continue;
1414 
1415                 if (vdev_validate_aux(vd) == 0)
1416                         spa_spare_add(vd);
1417         }
1418 
1419         /*
1420          * Recompute the stashed list of spares, with status information
1421          * this time.
1422          */
1423         VERIFY(nvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES,
1424             DATA_TYPE_NVLIST_ARRAY) == 0);
1425 
1426         spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
1427             KM_SLEEP);
1428         for (i = 0; i < spa->spa_spares.sav_count; i++)
1429                 spares[i] = vdev_config_generate(spa,
1430                     spa->spa_spares.sav_vdevs[i], B_TRUE, VDEV_CONFIG_SPARE);
1431         VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
1432             ZPOOL_CONFIG_SPARES, spares, spa->spa_spares.sav_count) == 0);
1433         for (i = 0; i < spa->spa_spares.sav_count; i++)
1434                 nvlist_free(spares[i]);
1435         kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
1436 }
1437 
1438 /*
1439  * Load (or re-load) the current list of vdevs describing the active l2cache for
1440  * this pool.  When this is called, we have some form of basic information in
1441  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
1442  * then re-generate a more complete list including status information.
1443  * Devices which are already active have their details maintained, and are
1444  * not re-opened.
1445  */
1446 static void
1447 spa_load_l2cache(spa_t *spa)
1448 {
1449         nvlist_t **l2cache;
1450         uint_t nl2cache;
1451         int i, j, oldnvdevs;
1452         uint64_t guid;
1453         vdev_t *vd, **oldvdevs, **newvdevs;
1454         spa_aux_vdev_t *sav = &spa->spa_l2cache;
1455 
1456         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1457 
1458         if (sav->sav_config != NULL) {
1459                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
1460                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1461                 newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
1462         } else {
1463                 nl2cache = 0;
1464                 newvdevs = NULL;
1465         }
1466 
1467         oldvdevs = sav->sav_vdevs;
1468         oldnvdevs = sav->sav_count;
1469         sav->sav_vdevs = NULL;
1470         sav->sav_count = 0;
1471 
1472         /*
1473          * Process new nvlist of vdevs.
1474          */
1475         for (i = 0; i < nl2cache; i++) {
1476                 VERIFY(nvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID,
1477                     &guid) == 0);
1478 
1479                 newvdevs[i] = NULL;
1480                 for (j = 0; j < oldnvdevs; j++) {
1481                         vd = oldvdevs[j];
1482                         if (vd != NULL && guid == vd->vdev_guid) {
1483                                 /*
1484                                  * Retain previous vdev for add/remove ops.
1485                                  */
1486                                 newvdevs[i] = vd;
1487                                 oldvdevs[j] = NULL;
1488                                 break;
1489                         }
1490                 }
1491 
1492                 if (newvdevs[i] == NULL) {
1493                         /*
1494                          * Create new vdev
1495                          */
1496                         VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
1497                             VDEV_ALLOC_L2CACHE) == 0);
1498                         ASSERT(vd != NULL);
1499                         newvdevs[i] = vd;
1500 
1501                         /*
1502                          * Commit this vdev as an l2cache device,
1503                          * even if it fails to open.
1504                          */
1505                         spa_l2cache_add(vd);
1506 
1507                         vd->vdev_top = vd;
1508                         vd->vdev_aux = sav;
1509 
1510                         spa_l2cache_activate(vd);
1511 
1512                         if (vdev_open(vd) != 0)
1513                                 continue;
1514 
1515                         (void) vdev_validate_aux(vd);
1516 
1517                         if (!vdev_is_dead(vd))
1518                                 l2arc_add_vdev(spa, vd);
1519                 }
1520         }
1521 
1522         /*
1523          * Purge vdevs that were dropped
1524          */
1525         for (i = 0; i < oldnvdevs; i++) {
1526                 uint64_t pool;
1527 
1528                 vd = oldvdevs[i];
1529                 if (vd != NULL) {
1530                         ASSERT(vd->vdev_isl2cache);
1531 
1532                         if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
1533                             pool != 0ULL && l2arc_vdev_present(vd))
1534                                 l2arc_remove_vdev(vd);
1535                         vdev_clear_stats(vd);
1536                         vdev_free(vd);
1537                 }
1538         }
1539 
1540         if (oldvdevs)
1541                 kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
1542 
1543         if (sav->sav_config == NULL)
1544                 goto out;
1545 
1546         sav->sav_vdevs = newvdevs;
1547         sav->sav_count = (int)nl2cache;
1548 
1549         /*
1550          * Recompute the stashed list of l2cache devices, with status
1551          * information this time.
1552          */
1553         VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
1554             DATA_TYPE_NVLIST_ARRAY) == 0);
1555 
1556         l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
1557         for (i = 0; i < sav->sav_count; i++)
1558                 l2cache[i] = vdev_config_generate(spa,
1559                     sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);
1560         VERIFY(nvlist_add_nvlist_array(sav->sav_config,
1561             ZPOOL_CONFIG_L2CACHE, l2cache, sav->sav_count) == 0);
1562 out:
1563         for (i = 0; i < sav->sav_count; i++)
1564                 nvlist_free(l2cache[i]);
1565         if (sav->sav_count)
1566                 kmem_free(l2cache, sav->sav_count * sizeof (void *));
1567 }
1568 
1569 static int
1570 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
1571 {
1572         dmu_buf_t *db;
1573         char *packed = NULL;
1574         size_t nvsize = 0;
1575         int error;
1576         *value = NULL;
1577 
1578         error = dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db);
1579         if (error != 0)
1580                 return (error);
1581 
1582         nvsize = *(uint64_t *)db->db_data;
1583         dmu_buf_rele(db, FTAG);
1584 
1585         packed = kmem_alloc(nvsize, KM_SLEEP);
1586         error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
1587             DMU_READ_PREFETCH);
1588         if (error == 0)
1589                 error = nvlist_unpack(packed, nvsize, value, 0);
1590         kmem_free(packed, nvsize);
1591 
1592         return (error);
1593 }
1594 
1595 /*
1596  * Checks to see if the given vdev could not be opened, in which case we post a
1597  * sysevent to notify the autoreplace code that the device has been removed.
1598  */
1599 static void
1600 spa_check_removed(vdev_t *vd)
1601 {
1602         for (int c = 0; c < vd->vdev_children; c++)
1603                 spa_check_removed(vd->vdev_child[c]);
1604 
1605         if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd) &&
1606             !vd->vdev_ishole) {
1607                 zfs_post_autoreplace(vd->vdev_spa, vd);
1608                 spa_event_notify(vd->vdev_spa, vd, ESC_ZFS_VDEV_CHECK);
1609         }
1610 }
1611 
1612 /*
1613  * Validate the current config against the MOS config
1614  */
1615 static boolean_t
1616 spa_config_valid(spa_t *spa, nvlist_t *config)
1617 {
1618         vdev_t *mrvd, *rvd = spa->spa_root_vdev;
1619         nvlist_t *nv;
1620 
1621         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nv) == 0);
1622 
1623         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1624         VERIFY(spa_config_parse(spa, &mrvd, nv, NULL, 0, VDEV_ALLOC_LOAD) == 0);
1625 
1626         ASSERT3U(rvd->vdev_children, ==, mrvd->vdev_children);
1627 
1628         /*
1629          * If we're doing a normal import, then build up any additional
1630          * diagnostic information about missing devices in this config.
1631          * We'll pass this up to the user for further processing.
1632          */
1633         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG)) {
1634                 nvlist_t **child, *nv;
1635                 uint64_t idx = 0;
1636 
1637                 child = kmem_alloc(rvd->vdev_children * sizeof (nvlist_t **),
1638                     KM_SLEEP);
1639                 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1640 
1641                 for (int c = 0; c < rvd->vdev_children; c++) {
1642                         vdev_t *tvd = rvd->vdev_child[c];
1643                         vdev_t *mtvd  = mrvd->vdev_child[c];
1644 
1645                         if (tvd->vdev_ops == &vdev_missing_ops &&
1646                             mtvd->vdev_ops != &vdev_missing_ops &&
1647                             mtvd->vdev_islog)
1648                                 child[idx++] = vdev_config_generate(spa, mtvd,
1649                                     B_FALSE, 0);
1650                 }
1651 
1652                 if (idx) {
1653                         VERIFY(nvlist_add_nvlist_array(nv,
1654                             ZPOOL_CONFIG_CHILDREN, child, idx) == 0);
1655                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
1656                             ZPOOL_CONFIG_MISSING_DEVICES, nv) == 0);
1657 
1658                         for (int i = 0; i < idx; i++)
1659                                 nvlist_free(child[i]);
1660                 }
1661                 nvlist_free(nv);
1662                 kmem_free(child, rvd->vdev_children * sizeof (char **));
1663         }
1664 
1665         /*
1666          * Compare the root vdev tree with the information we have
1667          * from the MOS config (mrvd). Check each top-level vdev
1668          * with the corresponding MOS config top-level (mtvd).
1669          */
1670         for (int c = 0; c < rvd->vdev_children; c++) {
1671                 vdev_t *tvd = rvd->vdev_child[c];
1672                 vdev_t *mtvd  = mrvd->vdev_child[c];
1673 
1674                 /*
1675                  * Resolve any "missing" vdevs in the current configuration.
1676                  * If we find that the MOS config has more accurate information
1677                  * about the top-level vdev then use that vdev instead.
1678                  */
1679                 if (tvd->vdev_ops == &vdev_missing_ops &&
1680                     mtvd->vdev_ops != &vdev_missing_ops) {
1681 
1682                         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG))
1683                                 continue;
1684 
1685                         /*
1686                          * Device specific actions.
1687                          */
1688                         if (mtvd->vdev_islog) {
1689                                 spa_set_log_state(spa, SPA_LOG_CLEAR);
1690                         } else {
1691                                 /*
1692                                  * XXX - once we have 'readonly' pool
1693                                  * support we should be able to handle
1694                                  * missing data devices by transitioning
1695                                  * the pool to readonly.
1696                                  */
1697                                 continue;
1698                         }
1699 
1700                         /*
1701                          * Swap the missing vdev with the data we were
1702                          * able to obtain from the MOS config.
1703                          */
1704                         vdev_remove_child(rvd, tvd);
1705                         vdev_remove_child(mrvd, mtvd);
1706 
1707                         vdev_add_child(rvd, mtvd);
1708                         vdev_add_child(mrvd, tvd);
1709 
1710                         spa_config_exit(spa, SCL_ALL, FTAG);
1711                         vdev_load(mtvd);
1712                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1713 
1714                         vdev_reopen(rvd);
1715                 } else if (mtvd->vdev_islog) {
1716                         /*
1717                          * Load the slog device's state from the MOS config
1718                          * since it's possible that the label does not
1719                          * contain the most up-to-date information.
1720                          */
1721                         vdev_load_log_state(tvd, mtvd);
1722                         vdev_reopen(tvd);
1723                 }
1724         }
1725         vdev_free(mrvd);
1726         spa_config_exit(spa, SCL_ALL, FTAG);
1727 
1728         /*
1729          * Ensure we were able to validate the config.
1730          */
1731         return (rvd->vdev_guid_sum == spa->spa_uberblock.ub_guid_sum);
1732 }
1733 
1734 /*
1735  * Check for missing log devices
1736  */
1737 static boolean_t
1738 spa_check_logs(spa_t *spa)
1739 {
1740         boolean_t rv = B_FALSE;
1741 
1742         switch (spa->spa_log_state) {
1743         case SPA_LOG_MISSING:
1744                 /* need to recheck in case slog has been restored */
1745         case SPA_LOG_UNKNOWN:
1746                 rv = (dmu_objset_find(spa->spa_name, zil_check_log_chain,
1747                     NULL, DS_FIND_CHILDREN) != 0);
1748                 if (rv)
1749                         spa_set_log_state(spa, SPA_LOG_MISSING);
1750                 break;
1751         }
1752         return (rv);
1753 }
1754 
1755 static boolean_t
1756 spa_passivate_log(spa_t *spa)
1757 {
1758         vdev_t *rvd = spa->spa_root_vdev;
1759         boolean_t slog_found = B_FALSE;
1760 
1761         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1762 
1763         if (!spa_has_slogs(spa))
1764                 return (B_FALSE);
1765 
1766         for (int c = 0; c < rvd->vdev_children; c++) {
1767                 vdev_t *tvd = rvd->vdev_child[c];
1768                 metaslab_group_t *mg = tvd->vdev_mg;
1769 
1770                 if (tvd->vdev_islog) {
1771                         metaslab_group_passivate(mg);
1772                         slog_found = B_TRUE;
1773                 }
1774         }
1775 
1776         return (slog_found);
1777 }
1778 
1779 static void
1780 spa_activate_log(spa_t *spa)
1781 {
1782         vdev_t *rvd = spa->spa_root_vdev;
1783 
1784         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1785 
1786         for (int c = 0; c < rvd->vdev_children; c++) {
1787                 vdev_t *tvd = rvd->vdev_child[c];
1788                 metaslab_group_t *mg = tvd->vdev_mg;
1789 
1790                 if (tvd->vdev_islog)
1791                         metaslab_group_activate(mg);
1792         }
1793 }
1794 
1795 int
1796 spa_offline_log(spa_t *spa)
1797 {
1798         int error;
1799 
1800         error = dmu_objset_find(spa_name(spa), zil_vdev_offline,
1801             NULL, DS_FIND_CHILDREN);
1802         if (error == 0) {
1803                 /*
1804                  * We successfully offlined the log device, sync out the
1805                  * current txg so that the "stubby" block can be removed
1806                  * by zil_sync().
1807                  */
1808                 txg_wait_synced(spa->spa_dsl_pool, 0);
1809         }
1810         return (error);
1811 }
1812 
1813 static void
1814 spa_aux_check_removed(spa_aux_vdev_t *sav)
1815 {
1816         for (int i = 0; i < sav->sav_count; i++)
1817                 spa_check_removed(sav->sav_vdevs[i]);
1818 }
1819 
1820 void
1821 spa_claim_notify(zio_t *zio)
1822 {
1823         spa_t *spa = zio->io_spa;
1824 
1825         if (zio->io_error)
1826                 return;
1827 
1828         mutex_enter(&spa->spa_props_lock);       /* any mutex will do */
1829         if (spa->spa_claim_max_txg < zio->io_bp->blk_birth)
1830                 spa->spa_claim_max_txg = zio->io_bp->blk_birth;
1831         mutex_exit(&spa->spa_props_lock);
1832 }
1833 
1834 typedef struct spa_load_error {
1835         uint64_t        sle_meta_count;
1836         uint64_t        sle_data_count;
1837 } spa_load_error_t;
1838 
1839 static void
1840 spa_load_verify_done(zio_t *zio)
1841 {
1842         blkptr_t *bp = zio->io_bp;
1843         spa_load_error_t *sle = zio->io_private;
1844         dmu_object_type_t type = BP_GET_TYPE(bp);
1845         int error = zio->io_error;
1846         spa_t *spa = zio->io_spa;
1847 
1848         if (error) {
1849                 if ((BP_GET_LEVEL(bp) != 0 || DMU_OT_IS_METADATA(type)) &&
1850                     type != DMU_OT_INTENT_LOG)
1851                         atomic_inc_64(&sle->sle_meta_count);
1852                 else
1853                         atomic_inc_64(&sle->sle_data_count);
1854         }
1855         zio_data_buf_free(zio->io_data, zio->io_size);
1856 
1857         mutex_enter(&spa->spa_scrub_lock);
1858         spa->spa_scrub_inflight--;
1859         cv_broadcast(&spa->spa_scrub_io_cv);
1860         mutex_exit(&spa->spa_scrub_lock);
1861 }
1862 
1863 /*
1864  * Maximum number of concurrent scrub i/os to create while verifying
1865  * a pool while importing it.
1866  */
1867 int spa_load_verify_maxinflight = 10000;
1868 boolean_t spa_load_verify_metadata = B_TRUE;
1869 boolean_t spa_load_verify_data = B_TRUE;
1870 
1871 /*ARGSUSED*/
1872 static int
1873 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1874     const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
1875 {
1876         if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp))
1877                 return (0);
1878         /*
1879          * Note: normally this routine will not be called if
1880          * spa_load_verify_metadata is not set.  However, it may be useful
1881          * to manually set the flag after the traversal has begun.
1882          */
1883         if (!spa_load_verify_metadata)
1884                 return (0);
1885         if (BP_GET_BUFC_TYPE(bp) == ARC_BUFC_DATA && !spa_load_verify_data)
1886                 return (0);
1887 
1888         zio_t *rio = arg;
1889         size_t size = BP_GET_PSIZE(bp);
1890         void *data = zio_data_buf_alloc(size);
1891 
1892         mutex_enter(&spa->spa_scrub_lock);
1893         while (spa->spa_scrub_inflight >= spa_load_verify_maxinflight)
1894                 cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock);
1895         spa->spa_scrub_inflight++;
1896         mutex_exit(&spa->spa_scrub_lock);
1897 
1898         zio_nowait(zio_read(rio, spa, bp, data, size,
1899             spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
1900             ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
1901             ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
1902         return (0);
1903 }
1904 
1905 static int
1906 spa_load_verify(spa_t *spa)
1907 {
1908         zio_t *rio;
1909         spa_load_error_t sle = { 0 };
1910         zpool_rewind_policy_t policy;
1911         boolean_t verify_ok = B_FALSE;
1912         int error = 0;
1913 
1914         zpool_get_rewind_policy(spa->spa_config, &policy);
1915 
1916         if (policy.zrp_request & ZPOOL_NEVER_REWIND)
1917                 return (0);
1918 
1919         rio = zio_root(spa, NULL, &sle,
1920             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1921 
1922         if (spa_load_verify_metadata) {
1923                 error = traverse_pool(spa, spa->spa_verify_min_txg,
1924                     TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA,
1925                     spa_load_verify_cb, rio);
1926         }
1927 
1928         (void) zio_wait(rio);
1929 
1930         spa->spa_load_meta_errors = sle.sle_meta_count;
1931         spa->spa_load_data_errors = sle.sle_data_count;
1932 
1933         if (!error && sle.sle_meta_count <= policy.zrp_maxmeta &&
1934             sle.sle_data_count <= policy.zrp_maxdata) {
1935                 int64_t loss = 0;
1936 
1937                 verify_ok = B_TRUE;
1938                 spa->spa_load_txg = spa->spa_uberblock.ub_txg;
1939                 spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
1940 
1941                 loss = spa->spa_last_ubsync_txg_ts - spa->spa_load_txg_ts;
1942                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1943                     ZPOOL_CONFIG_LOAD_TIME, spa->spa_load_txg_ts) == 0);
1944                 VERIFY(nvlist_add_int64(spa->spa_load_info,
1945                     ZPOOL_CONFIG_REWIND_TIME, loss) == 0);
1946                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1947                     ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count) == 0);
1948         } else {
1949                 spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
1950         }
1951 
1952         if (error) {
1953                 if (error != ENXIO && error != EIO)
1954                         error = SET_ERROR(EIO);
1955                 return (error);
1956         }
1957 
1958         return (verify_ok ? 0 : EIO);
1959 }
1960 
1961 /*
1962  * Find a value in the pool props object.
1963  */
1964 static void
1965 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
1966 {
1967         (void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
1968             zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
1969 }
1970 
1971 /*
1972  * Find a value in the pool directory object.
1973  */
1974 static int
1975 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val)
1976 {
1977         return (zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1978             name, sizeof (uint64_t), 1, val));
1979 }
1980 
1981 static int
1982 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
1983 {
1984         vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
1985         return (err);
1986 }
1987 
1988 /*
1989  * Fix up config after a partly-completed split.  This is done with the
1990  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
1991  * pool have that entry in their config, but only the splitting one contains
1992  * a list of all the guids of the vdevs that are being split off.
1993  *
1994  * This function determines what to do with that list: either rejoin
1995  * all the disks to the pool, or complete the splitting process.  To attempt
1996  * the rejoin, each disk that is offlined is marked online again, and
1997  * we do a reopen() call.  If the vdev label for every disk that was
1998  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
1999  * then we call vdev_split() on each disk, and complete the split.
2000  *
2001  * Otherwise we leave the config alone, with all the vdevs in place in
2002  * the original pool.
2003  */
2004 static void
2005 spa_try_repair(spa_t *spa, nvlist_t *config)
2006 {
2007         uint_t extracted;
2008         uint64_t *glist;
2009         uint_t i, gcount;
2010         nvlist_t *nvl;
2011         vdev_t **vd;
2012         boolean_t attempt_reopen;
2013 
2014         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
2015                 return;
2016 
2017         /* check that the config is complete */
2018         if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
2019             &glist, &gcount) != 0)
2020                 return;
2021 
2022         vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
2023 
2024         /* attempt to online all the vdevs & validate */
2025         attempt_reopen = B_TRUE;
2026         for (i = 0; i < gcount; i++) {
2027                 if (glist[i] == 0)      /* vdev is hole */
2028                         continue;
2029 
2030                 vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
2031                 if (vd[i] == NULL) {
2032                         /*
2033                          * Don't bother attempting to reopen the disks;
2034                          * just do the split.
2035                          */
2036                         attempt_reopen = B_FALSE;
2037                 } else {
2038                         /* attempt to re-online it */
2039                         vd[i]->vdev_offline = B_FALSE;
2040                 }
2041         }
2042 
2043         if (attempt_reopen) {
2044                 vdev_reopen(spa->spa_root_vdev);
2045 
2046                 /* check each device to see what state it's in */
2047                 for (extracted = 0, i = 0; i < gcount; i++) {
2048                         if (vd[i] != NULL &&
2049                             vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
2050                                 break;
2051                         ++extracted;
2052                 }
2053         }
2054 
2055         /*
2056          * If every disk has been moved to the new pool, or if we never
2057          * even attempted to look at them, then we split them off for
2058          * good.
2059          */
2060         if (!attempt_reopen || gcount == extracted) {
2061                 for (i = 0; i < gcount; i++)
2062                         if (vd[i] != NULL)
2063                                 vdev_split(vd[i]);
2064                 vdev_reopen(spa->spa_root_vdev);
2065         }
2066 
2067         kmem_free(vd, gcount * sizeof (vdev_t *));
2068 }
2069 
2070 static int
2071 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
2072     boolean_t mosconfig)
2073 {
2074         nvlist_t *config = spa->spa_config;
2075         char *ereport = FM_EREPORT_ZFS_POOL;
2076         char *comment;
2077         int error;
2078         uint64_t pool_guid;
2079         nvlist_t *nvl;
2080 
2081         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
2082                 return (SET_ERROR(EINVAL));
2083 
2084         ASSERT(spa->spa_comment == NULL);
2085         if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
2086                 spa->spa_comment = spa_strdup(comment);
2087 
2088         /*
2089          * Versioning wasn't explicitly added to the label until later, so if
2090          * it's not present treat it as the initial version.
2091          */
2092         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
2093             &spa->spa_ubsync.ub_version) != 0)
2094                 spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
2095 
2096         (void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
2097             &spa->spa_config_txg);
2098 
2099         if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
2100             spa_guid_exists(pool_guid, 0)) {
2101                 error = SET_ERROR(EEXIST);
2102         } else {
2103                 spa->spa_config_guid = pool_guid;
2104 
2105                 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT,
2106                     &nvl) == 0) {
2107                         VERIFY(nvlist_dup(nvl, &spa->spa_config_splitting,
2108                             KM_SLEEP) == 0);
2109                 }
2110 
2111                 nvlist_free(spa->spa_load_info);
2112                 spa->spa_load_info = fnvlist_alloc();
2113 
2114                 gethrestime(&spa->spa_loaded_ts);
2115                 error = spa_load_impl(spa, pool_guid, config, state, type,
2116                     mosconfig, &ereport);
2117         }
2118 
2119         /*
2120          * Don't count references from objsets that are already closed
2121          * and are making their way through the eviction process.
2122          */
2123         spa_evicting_os_wait(spa);
2124         spa->spa_minref = refcount_count(&spa->spa_refcount);
2125         if (error) {
2126                 if (error != EEXIST) {
2127                         spa->spa_loaded_ts.tv_sec = 0;
2128                         spa->spa_loaded_ts.tv_nsec = 0;
2129                 }
2130                 if (error != EBADF) {
2131                         zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
2132                 }
2133         }
2134         spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
2135         spa->spa_ena = 0;
2136 
2137         return (error);
2138 }
2139 
2140 /*
2141  * Load an existing storage pool, using the pool's builtin spa_config as a
2142  * source of configuration information.
2143  */
2144 static int
2145 spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config,
2146     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
2147     char **ereport)
2148 {
2149         int error = 0;
2150         nvlist_t *nvroot = NULL;
2151         nvlist_t *label;
2152         vdev_t *rvd;
2153         uberblock_t *ub = &spa->spa_uberblock;
2154         uint64_t children, config_cache_txg = spa->spa_config_txg;
2155         int orig_mode = spa->spa_mode;
2156         int parse;
2157         uint64_t obj;
2158         boolean_t missing_feat_write = B_FALSE;
2159 
2160         /*
2161          * If this is an untrusted config, access the pool in read-only mode.
2162          * This prevents things like resilvering recently removed devices.
2163          */
2164         if (!mosconfig)
2165                 spa->spa_mode = FREAD;
2166 
2167         ASSERT(MUTEX_HELD(&spa_namespace_lock));
2168 
2169         spa->spa_load_state = state;
2170 
2171         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot))
2172                 return (SET_ERROR(EINVAL));
2173 
2174         parse = (type == SPA_IMPORT_EXISTING ?
2175             VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
2176 
2177         /*
2178          * Create "The Godfather" zio to hold all async IOs
2179          */
2180         spa->spa_async_zio_root = kmem_alloc(max_ncpus * sizeof (void *),
2181             KM_SLEEP);
2182         for (int i = 0; i < max_ncpus; i++) {
2183                 spa->spa_async_zio_root[i] = zio_root(spa, NULL, NULL,
2184                     ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
2185                     ZIO_FLAG_GODFATHER);
2186         }
2187 
2188         /*
2189          * Parse the configuration into a vdev tree.  We explicitly set the
2190          * value that will be returned by spa_version() since parsing the
2191          * configuration requires knowing the version number.
2192          */
2193         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2194         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, parse);
2195         spa_config_exit(spa, SCL_ALL, FTAG);
2196 
2197         if (error != 0)
2198                 return (error);
2199 
2200         ASSERT(spa->spa_root_vdev == rvd);
2201 
2202         if (type != SPA_IMPORT_ASSEMBLE) {
2203                 ASSERT(spa_guid(spa) == pool_guid);
2204         }
2205 
2206         /*
2207          * Try to open all vdevs, loading each label in the process.
2208          */
2209         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2210         error = vdev_open(rvd);
2211         spa_config_exit(spa, SCL_ALL, FTAG);
2212         if (error != 0)
2213                 return (error);
2214 
2215         /*
2216          * We need to validate the vdev labels against the configuration that
2217          * we have in hand, which is dependent on the setting of mosconfig. If
2218          * mosconfig is true then we're validating the vdev labels based on
2219          * that config.  Otherwise, we're validating against the cached config
2220          * (zpool.cache) that was read when we loaded the zfs module, and then
2221          * later we will recursively call spa_load() and validate against
2222          * the vdev config.
2223          *
2224          * If we're assembling a new pool that's been split off from an
2225          * existing pool, the labels haven't yet been updated so we skip
2226          * validation for now.
2227          */
2228         if (type != SPA_IMPORT_ASSEMBLE) {
2229                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2230                 error = vdev_validate(rvd, mosconfig);
2231                 spa_config_exit(spa, SCL_ALL, FTAG);
2232 
2233                 if (error != 0)
2234                         return (error);
2235 
2236                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2237                         return (SET_ERROR(ENXIO));
2238         }
2239 
2240         /*
2241          * Find the best uberblock.
2242          */
2243         vdev_uberblock_load(rvd, ub, &label);
2244 
2245         /*
2246          * If we weren't able to find a single valid uberblock, return failure.
2247          */
2248         if (ub->ub_txg == 0) {
2249                 nvlist_free(label);
2250                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
2251         }
2252 
2253         /*
2254          * If the pool has an unsupported version we can't open it.
2255          */
2256         if (!SPA_VERSION_IS_SUPPORTED(ub->ub_version)) {
2257                 nvlist_free(label);
2258                 return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
2259         }
2260 
2261         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2262                 nvlist_t *features;
2263 
2264                 /*
2265                  * If we weren't able to find what's necessary for reading the
2266                  * MOS in the label, return failure.
2267                  */
2268                 if (label == NULL || nvlist_lookup_nvlist(label,
2269                     ZPOOL_CONFIG_FEATURES_FOR_READ, &features) != 0) {
2270                         nvlist_free(label);
2271                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2272                             ENXIO));
2273                 }
2274 
2275                 /*
2276                  * Update our in-core representation with the definitive values
2277                  * from the label.
2278                  */
2279                 nvlist_free(spa->spa_label_features);
2280                 VERIFY(nvlist_dup(features, &spa->spa_label_features, 0) == 0);
2281         }
2282 
2283         nvlist_free(label);
2284 
2285         /*
2286          * Look through entries in the label nvlist's features_for_read. If
2287          * there is a feature listed there which we don't understand then we
2288          * cannot open a pool.
2289          */
2290         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2291                 nvlist_t *unsup_feat;
2292 
2293                 VERIFY(nvlist_alloc(&unsup_feat, NV_UNIQUE_NAME, KM_SLEEP) ==
2294                     0);
2295 
2296                 for (nvpair_t *nvp = nvlist_next_nvpair(spa->spa_label_features,
2297                     NULL); nvp != NULL;
2298                     nvp = nvlist_next_nvpair(spa->spa_label_features, nvp)) {
2299                         if (!zfeature_is_supported(nvpair_name(nvp))) {
2300                                 VERIFY(nvlist_add_string(unsup_feat,
2301                                     nvpair_name(nvp), "") == 0);
2302                         }
2303                 }
2304 
2305                 if (!nvlist_empty(unsup_feat)) {
2306                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
2307                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat) == 0);
2308                         nvlist_free(unsup_feat);
2309                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2310                             ENOTSUP));
2311                 }
2312 
2313                 nvlist_free(unsup_feat);
2314         }
2315 
2316         /*
2317          * If the vdev guid sum doesn't match the uberblock, we have an
2318          * incomplete configuration.  We first check to see if the pool
2319          * is aware of the complete config (i.e ZPOOL_CONFIG_VDEV_CHILDREN).
2320          * If it is, defer the vdev_guid_sum check till later so we
2321          * can handle missing vdevs.
2322          */
2323         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN,
2324             &children) != 0 && mosconfig && type != SPA_IMPORT_ASSEMBLE &&
2325             rvd->vdev_guid_sum != ub->ub_guid_sum)
2326                 return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
2327 
2328         if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
2329                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2330                 spa_try_repair(spa, config);
2331                 spa_config_exit(spa, SCL_ALL, FTAG);
2332                 nvlist_free(spa->spa_config_splitting);
2333                 spa->spa_config_splitting = NULL;
2334         }
2335 
2336         /*
2337          * Initialize internal SPA structures.
2338          */
2339         spa->spa_state = POOL_STATE_ACTIVE;
2340         spa->spa_ubsync = spa->spa_uberblock;
2341         spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
2342             TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
2343         spa->spa_first_txg = spa->spa_last_ubsync_txg ?
2344             spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
2345         spa->spa_claim_max_txg = spa->spa_first_txg;
2346         spa->spa_prev_software_version = ub->ub_software_version;
2347 
2348         error = dsl_pool_init(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
2349         if (error)
2350                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2351         spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
2352 
2353         if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object) != 0)
2354                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2355 
2356         if (spa_version(spa) >= SPA_VERSION_FEATURES) {
2357                 boolean_t missing_feat_read = B_FALSE;
2358                 nvlist_t *unsup_feat, *enabled_feat;
2359 
2360                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_READ,
2361                     &spa->spa_feat_for_read_obj) != 0) {
2362                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2363                 }
2364 
2365                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_WRITE,
2366                     &spa->spa_feat_for_write_obj) != 0) {
2367                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2368                 }
2369 
2370                 if (spa_dir_prop(spa, DMU_POOL_FEATURE_DESCRIPTIONS,
2371                     &spa->spa_feat_desc_obj) != 0) {
2372                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2373                 }
2374 
2375                 enabled_feat = fnvlist_alloc();
2376                 unsup_feat = fnvlist_alloc();
2377 
2378                 if (!spa_features_check(spa, B_FALSE,
2379                     unsup_feat, enabled_feat))
2380                         missing_feat_read = B_TRUE;
2381 
2382                 if (spa_writeable(spa) || state == SPA_LOAD_TRYIMPORT) {
2383                         if (!spa_features_check(spa, B_TRUE,
2384                             unsup_feat, enabled_feat)) {
2385                                 missing_feat_write = B_TRUE;
2386                         }
2387                 }
2388 
2389                 fnvlist_add_nvlist(spa->spa_load_info,
2390                     ZPOOL_CONFIG_ENABLED_FEAT, enabled_feat);
2391 
2392                 if (!nvlist_empty(unsup_feat)) {
2393                         fnvlist_add_nvlist(spa->spa_load_info,
2394                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
2395                 }
2396 
2397                 fnvlist_free(enabled_feat);
2398                 fnvlist_free(unsup_feat);
2399 
2400                 if (!missing_feat_read) {
2401                         fnvlist_add_boolean(spa->spa_load_info,
2402                             ZPOOL_CONFIG_CAN_RDONLY);
2403                 }
2404 
2405                 /*
2406                  * If the state is SPA_LOAD_TRYIMPORT, our objective is
2407                  * twofold: to determine whether the pool is available for
2408                  * import in read-write mode and (if it is not) whether the
2409                  * pool is available for import in read-only mode. If the pool
2410                  * is available for import in read-write mode, it is displayed
2411                  * as available in userland; if it is not available for import
2412                  * in read-only mode, it is displayed as unavailable in
2413                  * userland. If the pool is available for import in read-only
2414                  * mode but not read-write mode, it is displayed as unavailable
2415                  * in userland with a special note that the pool is actually
2416                  * available for open in read-only mode.
2417                  *
2418                  * As a result, if the state is SPA_LOAD_TRYIMPORT and we are
2419                  * missing a feature for write, we must first determine whether
2420                  * the pool can be opened read-only before returning to
2421                  * userland in order to know whether to display the
2422                  * abovementioned note.
2423                  */
2424                 if (missing_feat_read || (missing_feat_write &&
2425                     spa_writeable(spa))) {
2426                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2427                             ENOTSUP));
2428                 }
2429 
2430                 /*
2431                  * Load refcounts for ZFS features from disk into an in-memory
2432                  * cache during SPA initialization.
2433                  */
2434                 for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
2435                         uint64_t refcount;
2436 
2437                         error = feature_get_refcount_from_disk(spa,
2438                             &spa_feature_table[i], &refcount);
2439                         if (error == 0) {
2440                                 spa->spa_feat_refcount_cache[i] = refcount;
2441                         } else if (error == ENOTSUP) {
2442                                 spa->spa_feat_refcount_cache[i] =
2443                                     SPA_FEATURE_DISABLED;
2444                         } else {
2445                                 return (spa_vdev_err(rvd,
2446                                     VDEV_AUX_CORRUPT_DATA, EIO));
2447                         }
2448                 }
2449         }
2450 
2451         if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
2452                 if (spa_dir_prop(spa, DMU_POOL_FEATURE_ENABLED_TXG,
2453                     &spa->spa_feat_enabled_txg_obj) != 0)
2454                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2455         }
2456 
2457         spa->spa_is_initializing = B_TRUE;
2458         error = dsl_pool_open(spa->spa_dsl_pool);
2459         spa->spa_is_initializing = B_FALSE;
2460         if (error != 0)
2461                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2462 
2463         if (!mosconfig) {
2464                 uint64_t hostid;
2465                 nvlist_t *policy = NULL, *nvconfig;
2466 
2467                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2468                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2469 
2470                 if (!spa_is_root(spa) && nvlist_lookup_uint64(nvconfig,
2471                     ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
2472                         char *hostname;
2473                         unsigned long myhostid = 0;
2474 
2475                         VERIFY(nvlist_lookup_string(nvconfig,
2476                             ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
2477 
2478 #ifdef  _KERNEL
2479                         myhostid = zone_get_hostid(NULL);
2480 #else   /* _KERNEL */
2481                         /*
2482                          * We're emulating the system's hostid in userland, so
2483                          * we can't use zone_get_hostid().
2484                          */
2485                         (void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
2486 #endif  /* _KERNEL */
2487                         if (hostid != 0 && myhostid != 0 &&
2488                             hostid != myhostid) {
2489                                 nvlist_free(nvconfig);
2490                                 cmn_err(CE_WARN, "pool '%s' could not be "
2491                                     "loaded as it was last accessed by "
2492                                     "another system (host: %s hostid: 0x%lx). "
2493                                     "See: http://illumos.org/msg/ZFS-8000-EY",
2494                                     spa_name(spa), hostname,
2495                                     (unsigned long)hostid);
2496                                 return (SET_ERROR(EBADF));
2497                         }
2498                 }
2499                 if (nvlist_lookup_nvlist(spa->spa_config,
2500                     ZPOOL_REWIND_POLICY, &policy) == 0)
2501                         VERIFY(nvlist_add_nvlist(nvconfig,
2502                             ZPOOL_REWIND_POLICY, policy) == 0);
2503 
2504                 spa_config_set(spa, nvconfig);
2505                 spa_unload(spa);
2506                 spa_deactivate(spa);
2507                 spa_activate(spa, orig_mode);
2508 
2509                 return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
2510         }
2511 
2512         if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj) != 0)
2513                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2514         error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
2515         if (error != 0)
2516                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2517 
2518         /*
2519          * Load the bit that tells us to use the new accounting function
2520          * (raid-z deflation).  If we have an older pool, this will not
2521          * be present.
2522          */
2523         error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate);
2524         if (error != 0 && error != ENOENT)
2525                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2526 
2527         error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
2528             &spa->spa_creation_version);
2529         if (error != 0 && error != ENOENT)
2530                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2531 
2532         /*
2533          * Load the persistent error log.  If we have an older pool, this will
2534          * not be present.
2535          */
2536         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last);
2537         if (error != 0 && error != ENOENT)
2538                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2539 
2540         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
2541             &spa->spa_errlog_scrub);
2542         if (error != 0 && error != ENOENT)
2543                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2544 
2545         /*
2546          * Load the history object.  If we have an older pool, this
2547          * will not be present.
2548          */
2549         error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history);
2550         if (error != 0 && error != ENOENT)
2551                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2552 
2553         /*
2554          * If we're assembling the pool from the split-off vdevs of
2555          * an existing pool, we don't want to attach the spares & cache
2556          * devices.
2557          */
2558 
2559         /*
2560          * Load any hot spares for this pool.
2561          */
2562         error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object);
2563         if (error != 0 && error != ENOENT)
2564                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2565         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2566                 ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
2567                 if (load_nvlist(spa, spa->spa_spares.sav_object,
2568                     &spa->spa_spares.sav_config) != 0)
2569                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2570 
2571                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2572                 spa_load_spares(spa);
2573                 spa_config_exit(spa, SCL_ALL, FTAG);
2574         } else if (error == 0) {
2575                 spa->spa_spares.sav_sync = B_TRUE;
2576         }
2577 
2578         /*
2579          * Load any level 2 ARC devices for this pool.
2580          */
2581         error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
2582             &spa->spa_l2cache.sav_object);
2583         if (error != 0 && error != ENOENT)
2584                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2585         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2586                 ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
2587                 if (load_nvlist(spa, spa->spa_l2cache.sav_object,
2588                     &spa->spa_l2cache.sav_config) != 0)
2589                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2590 
2591                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2592                 spa_load_l2cache(spa);
2593                 spa_config_exit(spa, SCL_ALL, FTAG);
2594         } else if (error == 0) {
2595                 spa->spa_l2cache.sav_sync = B_TRUE;
2596         }
2597 
2598         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2599 
2600         error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object);
2601         if (error && error != ENOENT)
2602                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2603 
2604         if (error == 0) {
2605                 uint64_t autoreplace;
2606 
2607                 spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
2608                 spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
2609                 spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
2610                 spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
2611                 spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
2612                 spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
2613                     &spa->spa_dedup_ditto);
2614 
2615                 spa->spa_autoreplace = (autoreplace != 0);
2616         }
2617 
2618         /*
2619          * If the 'autoreplace' property is set, then post a resource notifying
2620          * the ZFS DE that it should not issue any faults for unopenable
2621          * devices.  We also iterate over the vdevs, and post a sysevent for any
2622          * unopenable vdevs so that the normal autoreplace handler can take
2623          * over.
2624          */
2625         if (spa->spa_autoreplace && state != SPA_LOAD_TRYIMPORT) {
2626                 spa_check_removed(spa->spa_root_vdev);
2627                 /*
2628                  * For the import case, this is done in spa_import(), because
2629                  * at this point we're using the spare definitions from
2630                  * the MOS config, not necessarily from the userland config.
2631                  */
2632                 if (state != SPA_LOAD_IMPORT) {
2633                         spa_aux_check_removed(&spa->spa_spares);
2634                         spa_aux_check_removed(&spa->spa_l2cache);
2635                 }
2636         }
2637 
2638         /*
2639          * Load the vdev state for all toplevel vdevs.
2640          */
2641         vdev_load(rvd);
2642 
2643         /*
2644          * Propagate the leaf DTLs we just loaded all the way up the tree.
2645          */
2646         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2647         vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
2648         spa_config_exit(spa, SCL_ALL, FTAG);
2649 
2650         /*
2651          * Load the DDTs (dedup tables).
2652          */
2653         error = ddt_load(spa);
2654         if (error != 0)
2655                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2656 
2657         spa_update_dspace(spa);
2658 
2659         /*
2660          * Validate the config, using the MOS config to fill in any
2661          * information which might be missing.  If we fail to validate
2662          * the config then declare the pool unfit for use. If we're
2663          * assembling a pool from a split, the log is not transferred
2664          * over.
2665          */
2666         if (type != SPA_IMPORT_ASSEMBLE) {
2667                 nvlist_t *nvconfig;
2668 
2669                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2670                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2671 
2672                 if (!spa_config_valid(spa, nvconfig)) {
2673                         nvlist_free(nvconfig);
2674                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
2675                             ENXIO));
2676                 }
2677                 nvlist_free(nvconfig);
2678 
2679                 /*
2680                  * Now that we've validated the config, check the state of the
2681                  * root vdev.  If it can't be opened, it indicates one or
2682                  * more toplevel vdevs are faulted.
2683                  */
2684                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2685                         return (SET_ERROR(ENXIO));
2686 
2687                 if (spa_check_logs(spa)) {
2688                         *ereport = FM_EREPORT_ZFS_LOG_REPLAY;
2689                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG, ENXIO));
2690                 }
2691         }
2692 
2693         if (missing_feat_write) {
2694                 ASSERT(state == SPA_LOAD_TRYIMPORT);
2695 
2696                 /*
2697                  * At this point, we know that we can open the pool in
2698                  * read-only mode but not read-write mode. We now have enough
2699                  * information and can return to userland.
2700                  */
2701                 return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT, ENOTSUP));
2702         }
2703 
2704         /*
2705          * We've successfully opened the pool, verify that we're ready
2706          * to start pushing transactions.
2707          */
2708         if (state != SPA_LOAD_TRYIMPORT) {
2709                 if (error = spa_load_verify(spa))
2710                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2711                             error));
2712         }
2713 
2714         if (spa_writeable(spa) && (state == SPA_LOAD_RECOVER ||
2715             spa->spa_load_max_txg == UINT64_MAX)) {
2716                 dmu_tx_t *tx;
2717                 int need_update = B_FALSE;
2718 
2719                 ASSERT(state != SPA_LOAD_TRYIMPORT);
2720 
2721                 /*
2722                  * Claim log blocks that haven't been committed yet.
2723                  * This must all happen in a single txg.
2724                  * Note: spa_claim_max_txg is updated by spa_claim_notify(),
2725                  * invoked from zil_claim_log_block()'s i/o done callback.
2726                  * Price of rollback is that we abandon the log.
2727                  */
2728                 spa->spa_claiming = B_TRUE;
2729 
2730                 tx = dmu_tx_create_assigned(spa_get_dsl(spa),
2731                     spa_first_txg(spa));
2732                 (void) dmu_objset_find(spa_name(spa),
2733                     zil_claim, tx, DS_FIND_CHILDREN);
2734                 dmu_tx_commit(tx);
2735 
2736                 spa->spa_claiming = B_FALSE;
2737 
2738                 spa_set_log_state(spa, SPA_LOG_GOOD);
2739                 spa->spa_sync_on = B_TRUE;
2740                 txg_sync_start(spa->spa_dsl_pool);
2741 
2742                 /*
2743                  * Wait for all claims to sync.  We sync up to the highest
2744                  * claimed log block birth time so that claimed log blocks
2745                  * don't appear to be from the future.  spa_claim_max_txg
2746                  * will have been set for us by either zil_check_log_chain()
2747                  * (invoked from spa_check_logs()) or zil_claim() above.
2748                  */
2749                 txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
2750 
2751                 /*
2752                  * If the config cache is stale, or we have uninitialized
2753                  * metaslabs (see spa_vdev_add()), then update the config.
2754                  *
2755                  * If this is a verbatim import, trust the current
2756                  * in-core spa_config and update the disk labels.
2757                  */
2758                 if (config_cache_txg != spa->spa_config_txg ||
2759                     state == SPA_LOAD_IMPORT ||
2760                     state == SPA_LOAD_RECOVER ||
2761                     (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
2762                         need_update = B_TRUE;
2763 
2764                 for (int c = 0; c < rvd->vdev_children; c++)
2765                         if (rvd->vdev_child[c]->vdev_ms_array == 0)
2766                                 need_update = B_TRUE;
2767 
2768                 /*
2769                  * Update the config cache asychronously in case we're the
2770                  * root pool, in which case the config cache isn't writable yet.
2771                  */
2772                 if (need_update)
2773                         spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2774 
2775                 /*
2776                  * Check all DTLs to see if anything needs resilvering.
2777                  */
2778                 if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
2779                     vdev_resilver_needed(rvd, NULL, NULL))
2780                         spa_async_request(spa, SPA_ASYNC_RESILVER);
2781 
2782                 /*
2783                  * Log the fact that we booted up (so that we can detect if
2784                  * we rebooted in the middle of an operation).
2785                  */
2786                 spa_history_log_version(spa, "open");
2787 
2788                 /*
2789                  * Delete any inconsistent datasets.
2790                  */
2791                 (void) dmu_objset_find(spa_name(spa),
2792                     dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
2793 
2794                 /*
2795                  * Clean up any stale temporary dataset userrefs.
2796                  */
2797                 dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
2798         }
2799 
2800         return (0);
2801 }
2802 
2803 static int
2804 spa_load_retry(spa_t *spa, spa_load_state_t state, int mosconfig)
2805 {
2806         int mode = spa->spa_mode;
2807 
2808         spa_unload(spa);
2809         spa_deactivate(spa);
2810 
2811         spa->spa_load_max_txg = spa->spa_uberblock.ub_txg - 1;
2812 
2813         spa_activate(spa, mode);
2814         spa_async_suspend(spa);
2815 
2816         return (spa_load(spa, state, SPA_IMPORT_EXISTING, mosconfig));
2817 }
2818 
2819 /*
2820  * If spa_load() fails this function will try loading prior txg's. If
2821  * 'state' is SPA_LOAD_RECOVER and one of these loads succeeds the pool
2822  * will be rewound to that txg. If 'state' is not SPA_LOAD_RECOVER this
2823  * function will not rewind the pool and will return the same error as
2824  * spa_load().
2825  */
2826 static int
2827 spa_load_best(spa_t *spa, spa_load_state_t state, int mosconfig,
2828     uint64_t max_request, int rewind_flags)
2829 {
2830         nvlist_t *loadinfo = NULL;
2831         nvlist_t *config = NULL;
2832         int load_error, rewind_error;
2833         uint64_t safe_rewind_txg;
2834         uint64_t min_txg;
2835 
2836         if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
2837                 spa->spa_load_max_txg = spa->spa_load_txg;
2838                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2839         } else {
2840                 spa->spa_load_max_txg = max_request;
2841                 if (max_request != UINT64_MAX)
2842                         spa->spa_extreme_rewind = B_TRUE;
2843         }
2844 
2845         load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING,
2846             mosconfig);
2847         if (load_error == 0)
2848                 return (0);
2849 
2850         if (spa->spa_root_vdev != NULL)
2851                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2852 
2853         spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
2854         spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
2855 
2856         if (rewind_flags & ZPOOL_NEVER_REWIND) {
2857                 nvlist_free(config);
2858                 return (load_error);
2859         }
2860 
2861         if (state == SPA_LOAD_RECOVER) {
2862                 /* Price of rolling back is discarding txgs, including log */
2863                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2864         } else {
2865                 /*
2866                  * If we aren't rolling back save the load info from our first
2867                  * import attempt so that we can restore it after attempting
2868                  * to rewind.
2869                  */
2870                 loadinfo = spa->spa_load_info;
2871                 spa->spa_load_info = fnvlist_alloc();
2872         }
2873 
2874         spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
2875         safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
2876         min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
2877             TXG_INITIAL : safe_rewind_txg;
2878 
2879         /*
2880          * Continue as long as we're finding errors, we're still within
2881          * the acceptable rewind range, and we're still finding uberblocks
2882          */
2883         while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
2884             spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
2885                 if (spa->spa_load_max_txg < safe_rewind_txg)
2886                         spa->spa_extreme_rewind = B_TRUE;
2887                 rewind_error = spa_load_retry(spa, state, mosconfig);
2888         }
2889 
2890         spa->spa_extreme_rewind = B_FALSE;
2891         spa->spa_load_max_txg = UINT64_MAX;
2892 
2893         if (config && (rewind_error || state != SPA_LOAD_RECOVER))
2894                 spa_config_set(spa, config);
2895 
2896         if (state == SPA_LOAD_RECOVER) {
2897                 ASSERT3P(loadinfo, ==, NULL);
2898                 return (rewind_error);
2899         } else {
2900                 /* Store the rewind info as part of the initial load info */
2901                 fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
2902                     spa->spa_load_info);
2903 
2904                 /* Restore the initial load info */
2905                 fnvlist_free(spa->spa_load_info);
2906                 spa->spa_load_info = loadinfo;
2907 
2908                 return (load_error);
2909         }
2910 }
2911 
2912 /*
2913  * Pool Open/Import
2914  *
2915  * The import case is identical to an open except that the configuration is sent
2916  * down from userland, instead of grabbed from the configuration cache.  For the
2917  * case of an open, the pool configuration will exist in the
2918  * POOL_STATE_UNINITIALIZED state.
2919  *
2920  * The stats information (gen/count/ustats) is used to gather vdev statistics at
2921  * the same time open the pool, without having to keep around the spa_t in some
2922  * ambiguous state.
2923  */
2924 static int
2925 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
2926     nvlist_t **config)
2927 {
2928         spa_t *spa;
2929         spa_load_state_t state = SPA_LOAD_OPEN;
2930         int error;
2931         int locked = B_FALSE;
2932 
2933         *spapp = NULL;
2934 
2935         /*
2936          * As disgusting as this is, we need to support recursive calls to this
2937          * function because dsl_dir_open() is called during spa_load(), and ends
2938          * up calling spa_open() again.  The real fix is to figure out how to
2939          * avoid dsl_dir_open() calling this in the first place.
2940          */
2941         if (mutex_owner(&spa_namespace_lock) != curthread) {
2942                 mutex_enter(&spa_namespace_lock);
2943                 locked = B_TRUE;
2944         }
2945 
2946         if ((spa = spa_lookup(pool)) == NULL) {
2947                 if (locked)
2948                         mutex_exit(&spa_namespace_lock);
2949                 return (SET_ERROR(ENOENT));
2950         }
2951 
2952         if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
2953                 zpool_rewind_policy_t policy;
2954 
2955                 zpool_get_rewind_policy(nvpolicy ? nvpolicy : spa->spa_config,
2956                     &policy);
2957                 if (policy.zrp_request & ZPOOL_DO_REWIND)
2958                         state = SPA_LOAD_RECOVER;
2959 
2960                 spa_activate(spa, spa_mode_global);
2961 
2962                 if (state != SPA_LOAD_RECOVER)
2963                         spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
2964 
2965                 error = spa_load_best(spa, state, B_FALSE, policy.zrp_txg,
2966                     policy.zrp_request);
2967 
2968                 if (error == EBADF) {
2969                         /*
2970                          * If vdev_validate() returns failure (indicated by
2971                          * EBADF), it indicates that one of the vdevs indicates
2972                          * that the pool has been exported or destroyed.  If
2973                          * this is the case, the config cache is out of sync and
2974                          * we should remove the pool from the namespace.
2975                          */
2976                         spa_unload(spa);
2977                         spa_deactivate(spa);
2978                         spa_config_sync(spa, B_TRUE, B_TRUE);
2979                         spa_remove(spa);
2980                         if (locked)
2981                                 mutex_exit(&spa_namespace_lock);
2982                         return (SET_ERROR(ENOENT));
2983                 }
2984 
2985                 if (error) {
2986                         /*
2987                          * We can't open the pool, but we still have useful
2988                          * information: the state of each vdev after the
2989                          * attempted vdev_open().  Return this to the user.
2990                          */
2991                         if (config != NULL && spa->spa_config) {
2992                                 VERIFY(nvlist_dup(spa->spa_config, config,
2993                                     KM_SLEEP) == 0);
2994                                 VERIFY(nvlist_add_nvlist(*config,
2995                                     ZPOOL_CONFIG_LOAD_INFO,
2996                                     spa->spa_load_info) == 0);
2997                         }
2998                         spa_unload(spa);
2999                         spa_deactivate(spa);
3000                         spa->spa_last_open_failed = error;
3001                         if (locked)
3002                                 mutex_exit(&spa_namespace_lock);
3003                         *spapp = NULL;
3004                         return (error);
3005                 }
3006         }
3007 
3008         spa_open_ref(spa, tag);
3009 
3010         if (config != NULL)
3011                 *config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
3012 
3013         /*
3014          * If we've recovered the pool, pass back any information we
3015          * gathered while doing the load.
3016          */
3017         if (state == SPA_LOAD_RECOVER) {
3018                 VERIFY(nvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
3019                     spa->spa_load_info) == 0);
3020         }
3021 
3022         if (locked) {
3023                 spa->spa_last_open_failed = 0;
3024                 spa->spa_last_ubsync_txg = 0;
3025                 spa->spa_load_txg = 0;
3026                 mutex_exit(&spa_namespace_lock);
3027         }
3028 
3029         *spapp = spa;
3030 
3031         return (0);
3032 }
3033 
3034 int
3035 spa_open_rewind(const char *name, spa_t **spapp, void *tag, nvlist_t *policy,
3036     nvlist_t **config)
3037 {
3038         return (spa_open_common(name, spapp, tag, policy, config));
3039 }
3040 
3041 int
3042 spa_open(const char *name, spa_t **spapp, void *tag)
3043 {
3044         return (spa_open_common(name, spapp, tag, NULL, NULL));
3045 }
3046 
3047 /*
3048  * Lookup the given spa_t, incrementing the inject count in the process,
3049  * preventing it from being exported or destroyed.
3050  */
3051 spa_t *
3052 spa_inject_addref(char *name)
3053 {
3054         spa_t *spa;
3055 
3056         mutex_enter(&spa_namespace_lock);
3057         if ((spa = spa_lookup(name)) == NULL) {
3058                 mutex_exit(&spa_namespace_lock);
3059                 return (NULL);
3060         }
3061         spa->spa_inject_ref++;
3062         mutex_exit(&spa_namespace_lock);
3063 
3064         return (spa);
3065 }
3066 
3067 void
3068 spa_inject_delref(spa_t *spa)
3069 {
3070         mutex_enter(&spa_namespace_lock);
3071         spa->spa_inject_ref--;
3072         mutex_exit(&spa_namespace_lock);
3073 }
3074 
3075 /*
3076  * Add spares device information to the nvlist.
3077  */
3078 static void
3079 spa_add_spares(spa_t *spa, nvlist_t *config)
3080 {
3081         nvlist_t **spares;
3082         uint_t i, nspares;
3083         nvlist_t *nvroot;
3084         uint64_t guid;
3085         vdev_stat_t *vs;
3086         uint_t vsc;
3087         uint64_t pool;
3088 
3089         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3090 
3091         if (spa->spa_spares.sav_count == 0)
3092                 return;
3093 
3094         VERIFY(nvlist_lookup_nvlist(config,
3095             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3096         VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
3097             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
3098         if (nspares != 0) {
3099                 VERIFY(nvlist_add_nvlist_array(nvroot,
3100                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3101                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
3102                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
3103 
3104                 /*
3105                  * Go through and find any spares which have since been
3106                  * repurposed as an active spare.  If this is the case, update
3107                  * their status appropriately.
3108                  */
3109                 for (i = 0; i < nspares; i++) {
3110                         VERIFY(nvlist_lookup_uint64(spares[i],
3111                             ZPOOL_CONFIG_GUID, &guid) == 0);
3112                         if (spa_spare_exists(guid, &pool, NULL) &&
3113                             pool != 0ULL) {
3114                                 VERIFY(nvlist_lookup_uint64_array(
3115                                     spares[i], ZPOOL_CONFIG_VDEV_STATS,
3116                                     (uint64_t **)&vs, &vsc) == 0);
3117                                 vs->vs_state = VDEV_STATE_CANT_OPEN;
3118                                 vs->vs_aux = VDEV_AUX_SPARED;
3119                         }
3120                 }
3121         }
3122 }
3123 
3124 /*
3125  * Add l2cache device information to the nvlist, including vdev stats.
3126  */
3127 static void
3128 spa_add_l2cache(spa_t *spa, nvlist_t *config)
3129 {
3130         nvlist_t **l2cache;
3131         uint_t i, j, nl2cache;
3132         nvlist_t *nvroot;
3133         uint64_t guid;
3134         vdev_t *vd;
3135         vdev_stat_t *vs;
3136         uint_t vsc;
3137 
3138         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3139 
3140         if (spa->spa_l2cache.sav_count == 0)
3141                 return;
3142 
3143         VERIFY(nvlist_lookup_nvlist(config,
3144             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3145         VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
3146             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3147         if (nl2cache != 0) {
3148                 VERIFY(nvlist_add_nvlist_array(nvroot,
3149                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3150                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
3151                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3152 
3153                 /*
3154                  * Update level 2 cache device stats.
3155                  */
3156 
3157                 for (i = 0; i < nl2cache; i++) {
3158                         VERIFY(nvlist_lookup_uint64(l2cache[i],
3159                             ZPOOL_CONFIG_GUID, &guid) == 0);
3160 
3161                         vd = NULL;
3162                         for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
3163                                 if (guid ==
3164                                     spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
3165                                         vd = spa->spa_l2cache.sav_vdevs[j];
3166                                         break;
3167                                 }
3168                         }
3169                         ASSERT(vd != NULL);
3170 
3171                         VERIFY(nvlist_lookup_uint64_array(l2cache[i],
3172                             ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc)
3173                             == 0);
3174                         vdev_get_stats(vd, vs);
3175                 }
3176         }
3177 }
3178 
3179 static void
3180 spa_add_feature_stats(spa_t *spa, nvlist_t *config)
3181 {
3182         nvlist_t *features;
3183         zap_cursor_t zc;
3184         zap_attribute_t za;
3185 
3186         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3187         VERIFY(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3188 
3189         if (spa->spa_feat_for_read_obj != 0) {
3190                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3191                     spa->spa_feat_for_read_obj);
3192                     zap_cursor_retrieve(&zc, &za) == 0;
3193                     zap_cursor_advance(&zc)) {
3194                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3195                             za.za_num_integers == 1);
3196                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3197                             za.za_first_integer));
3198                 }
3199                 zap_cursor_fini(&zc);
3200         }
3201 
3202         if (spa->spa_feat_for_write_obj != 0) {
3203                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3204                     spa->spa_feat_for_write_obj);
3205                     zap_cursor_retrieve(&zc, &za) == 0;
3206                     zap_cursor_advance(&zc)) {
3207                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3208                             za.za_num_integers == 1);
3209                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3210                             za.za_first_integer));
3211                 }
3212                 zap_cursor_fini(&zc);
3213         }
3214 
3215         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
3216             features) == 0);
3217         nvlist_free(features);
3218 }
3219 
3220 int
3221 spa_get_stats(const char *name, nvlist_t **config,
3222     char *altroot, size_t buflen)
3223 {
3224         int error;
3225         spa_t *spa;
3226 
3227         *config = NULL;
3228         error = spa_open_common(name, &spa, FTAG, NULL, config);
3229 
3230         if (spa != NULL) {
3231                 /*
3232                  * This still leaves a window of inconsistency where the spares
3233                  * or l2cache devices could change and the config would be
3234                  * self-inconsistent.
3235                  */
3236                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3237 
3238                 if (*config != NULL) {
3239                         uint64_t loadtimes[2];
3240 
3241                         loadtimes[0] = spa->spa_loaded_ts.tv_sec;
3242                         loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
3243                         VERIFY(nvlist_add_uint64_array(*config,
3244                             ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2) == 0);
3245 
3246                         VERIFY(nvlist_add_uint64(*config,
3247                             ZPOOL_CONFIG_ERRCOUNT,
3248                             spa_get_errlog_size(spa)) == 0);
3249 
3250                         if (spa_suspended(spa))
3251                                 VERIFY(nvlist_add_uint64(*config,
3252                                     ZPOOL_CONFIG_SUSPENDED,
3253                                     spa->spa_failmode) == 0);
3254 
3255                         spa_add_spares(spa, *config);
3256                         spa_add_l2cache(spa, *config);
3257                         spa_add_feature_stats(spa, *config);
3258                 }
3259         }
3260 
3261         /*
3262          * We want to get the alternate root even for faulted pools, so we cheat
3263          * and call spa_lookup() directly.
3264          */
3265         if (altroot) {
3266                 if (spa == NULL) {
3267                         mutex_enter(&spa_namespace_lock);
3268                         spa = spa_lookup(name);
3269                         if (spa)
3270                                 spa_altroot(spa, altroot, buflen);
3271                         else
3272                                 altroot[0] = '\0';
3273                         spa = NULL;
3274                         mutex_exit(&spa_namespace_lock);
3275                 } else {
3276                         spa_altroot(spa, altroot, buflen);
3277                 }
3278         }
3279 
3280         if (spa != NULL) {
3281                 spa_config_exit(spa, SCL_CONFIG, FTAG);
3282                 spa_close(spa, FTAG);
3283         }
3284 
3285         return (error);
3286 }
3287 
3288 /*
3289  * Validate that the auxiliary device array is well formed.  We must have an
3290  * array of nvlists, each which describes a valid leaf vdev.  If this is an
3291  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
3292  * specified, as long as they are well-formed.
3293  */
3294 static int
3295 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
3296     spa_aux_vdev_t *sav, const char *config, uint64_t version,
3297     vdev_labeltype_t label)
3298 {
3299         nvlist_t **dev;
3300         uint_t i, ndev;
3301         vdev_t *vd;
3302         int error;
3303 
3304         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3305 
3306         /*
3307          * It's acceptable to have no devs specified.
3308          */
3309         if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
3310                 return (0);
3311 
3312         if (ndev == 0)
3313                 return (SET_ERROR(EINVAL));
3314 
3315         /*
3316          * Make sure the pool is formatted with a version that supports this
3317          * device type.
3318          */
3319         if (spa_version(spa) < version)
3320                 return (SET_ERROR(ENOTSUP));
3321 
3322         /*
3323          * Set the pending device list so we correctly handle device in-use
3324          * checking.
3325          */
3326         sav->sav_pending = dev;
3327         sav->sav_npending = ndev;
3328 
3329         for (i = 0; i < ndev; i++) {
3330                 if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
3331                     mode)) != 0)
3332                         goto out;
3333 
3334                 if (!vd->vdev_ops->vdev_op_leaf) {
3335                         vdev_free(vd);
3336                         error = SET_ERROR(EINVAL);
3337                         goto out;
3338                 }
3339 
3340                 /*
3341                  * The L2ARC currently only supports disk devices in
3342                  * kernel context.  For user-level testing, we allow it.
3343                  */
3344 #ifdef _KERNEL
3345                 if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
3346                     strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
3347                         error = SET_ERROR(ENOTBLK);
3348                         vdev_free(vd);
3349                         goto out;
3350                 }
3351 #endif
3352                 vd->vdev_top = vd;
3353 
3354                 if ((error = vdev_open(vd)) == 0 &&
3355                     (error = vdev_label_init(vd, crtxg, label)) == 0) {
3356                         VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
3357                             vd->vdev_guid) == 0);
3358                 }
3359 
3360                 vdev_free(vd);
3361 
3362                 if (error &&
3363                     (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
3364                         goto out;
3365                 else
3366                         error = 0;
3367         }
3368 
3369 out:
3370         sav->sav_pending = NULL;
3371         sav->sav_npending = 0;
3372         return (error);
3373 }
3374 
3375 static int
3376 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
3377 {
3378         int error;
3379 
3380         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3381 
3382         if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3383             &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
3384             VDEV_LABEL_SPARE)) != 0) {
3385                 return (error);
3386         }
3387 
3388         return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3389             &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
3390             VDEV_LABEL_L2CACHE));
3391 }
3392 
3393 static void
3394 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
3395     const char *config)
3396 {
3397         int i;
3398 
3399         if (sav->sav_config != NULL) {
3400                 nvlist_t **olddevs;
3401                 uint_t oldndevs;
3402                 nvlist_t **newdevs;
3403 
3404                 /*
3405                  * Generate new dev list by concatentating with the
3406                  * current dev list.
3407                  */
3408                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
3409                     &olddevs, &oldndevs) == 0);
3410 
3411                 newdevs = kmem_alloc(sizeof (void *) *
3412                     (ndevs + oldndevs), KM_SLEEP);
3413                 for (i = 0; i < oldndevs; i++)
3414                         VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
3415                             KM_SLEEP) == 0);
3416                 for (i = 0; i < ndevs; i++)
3417                         VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
3418                             KM_SLEEP) == 0);
3419 
3420                 VERIFY(nvlist_remove(sav->sav_config, config,
3421                     DATA_TYPE_NVLIST_ARRAY) == 0);
3422 
3423                 VERIFY(nvlist_add_nvlist_array(sav->sav_config,
3424                     config, newdevs, ndevs + oldndevs) == 0);
3425                 for (i = 0; i < oldndevs + ndevs; i++)
3426                         nvlist_free(newdevs[i]);
3427                 kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
3428         } else {
3429                 /*
3430                  * Generate a new dev list.
3431                  */
3432                 VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
3433                     KM_SLEEP) == 0);
3434                 VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
3435                     devs, ndevs) == 0);
3436         }
3437 }
3438 
3439 /*
3440  * Stop and drop level 2 ARC devices
3441  */
3442 void
3443 spa_l2cache_drop(spa_t *spa)
3444 {
3445         vdev_t *vd;
3446         int i;
3447         spa_aux_vdev_t *sav = &spa->spa_l2cache;
3448 
3449         for (i = 0; i < sav->sav_count; i++) {
3450                 uint64_t pool;
3451 
3452                 vd = sav->sav_vdevs[i];
3453                 ASSERT(vd != NULL);
3454 
3455                 if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
3456                     pool != 0ULL && l2arc_vdev_present(vd))
3457                         l2arc_remove_vdev(vd);
3458         }
3459 }
3460 
3461 /*
3462  * Pool Creation
3463  */
3464 int
3465 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
3466     nvlist_t *zplprops)
3467 {
3468         spa_t *spa;
3469         char *altroot = NULL;
3470         vdev_t *rvd;
3471         dsl_pool_t *dp;
3472         dmu_tx_t *tx;
3473         int error = 0;
3474         uint64_t txg = TXG_INITIAL;
3475         nvlist_t **spares, **l2cache;
3476         uint_t nspares, nl2cache;
3477         uint64_t version, obj;
3478         boolean_t has_features;
3479 
3480         /*
3481          * If this pool already exists, return failure.
3482          */
3483         mutex_enter(&spa_namespace_lock);
3484         if (spa_lookup(pool) != NULL) {
3485                 mutex_exit(&spa_namespace_lock);
3486                 return (SET_ERROR(EEXIST));
3487         }
3488 
3489         /*
3490          * Allocate a new spa_t structure.
3491          */
3492         (void) nvlist_lookup_string(props,
3493             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3494         spa = spa_add(pool, NULL, altroot);
3495         spa_activate(spa, spa_mode_global);
3496 
3497         if (props && (error = spa_prop_validate(spa, props))) {
3498                 spa_deactivate(spa);
3499                 spa_remove(spa);
3500                 mutex_exit(&spa_namespace_lock);
3501                 return (error);
3502         }
3503 
3504         has_features = B_FALSE;
3505         for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
3506             elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
3507                 if (zpool_prop_feature(nvpair_name(elem)))
3508                         has_features = B_TRUE;
3509         }
3510 
3511         if (has_features || nvlist_lookup_uint64(props,
3512             zpool_prop_to_name(ZPOOL_PROP_VERSION), &version) != 0) {
3513                 version = SPA_VERSION;
3514         }
3515         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
3516 
3517         spa->spa_first_txg = txg;
3518         spa->spa_uberblock.ub_txg = txg - 1;
3519         spa->spa_uberblock.ub_version = version;
3520         spa->spa_ubsync = spa->spa_uberblock;
3521 
3522         /*
3523          * Create "The Godfather" zio to hold all async IOs
3524          */
3525         spa->spa_async_zio_root = kmem_alloc(max_ncpus * sizeof (void *),
3526             KM_SLEEP);
3527         for (int i = 0; i < max_ncpus; i++) {
3528                 spa->spa_async_zio_root[i] = zio_root(spa, NULL, NULL,
3529                     ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
3530                     ZIO_FLAG_GODFATHER);
3531         }
3532 
3533         /*
3534          * Create the root vdev.
3535          */
3536         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3537 
3538         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
3539 
3540         ASSERT(error != 0 || rvd != NULL);
3541         ASSERT(error != 0 || spa->spa_root_vdev == rvd);
3542 
3543         if (error == 0 && !zfs_allocatable_devs(nvroot))
3544                 error = SET_ERROR(EINVAL);
3545 
3546         if (error == 0 &&
3547             (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
3548             (error = spa_validate_aux(spa, nvroot, txg,
3549             VDEV_ALLOC_ADD)) == 0) {
3550                 for (int c = 0; c < rvd->vdev_children; c++) {
3551                         vdev_metaslab_set_size(rvd->vdev_child[c]);
3552                         vdev_expand(rvd->vdev_child[c], txg);
3553                 }
3554         }
3555 
3556         spa_config_exit(spa, SCL_ALL, FTAG);
3557 
3558         if (error != 0) {
3559                 spa_unload(spa);
3560                 spa_deactivate(spa);
3561                 spa_remove(spa);
3562                 mutex_exit(&spa_namespace_lock);
3563                 return (error);
3564         }
3565 
3566         /*
3567          * Get the list of spares, if specified.
3568          */
3569         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3570             &spares, &nspares) == 0) {
3571                 VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
3572                     KM_SLEEP) == 0);
3573                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3574                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3575                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3576                 spa_load_spares(spa);
3577                 spa_config_exit(spa, SCL_ALL, FTAG);
3578                 spa->spa_spares.sav_sync = B_TRUE;
3579         }
3580 
3581         /*
3582          * Get the list of level 2 cache devices, if specified.
3583          */
3584         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3585             &l2cache, &nl2cache) == 0) {
3586                 VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3587                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
3588                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3589                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3590                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3591                 spa_load_l2cache(spa);
3592                 spa_config_exit(spa, SCL_ALL, FTAG);
3593                 spa->spa_l2cache.sav_sync = B_TRUE;
3594         }
3595 
3596         spa->spa_is_initializing = B_TRUE;
3597         spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
3598         spa->spa_meta_objset = dp->dp_meta_objset;
3599         spa->spa_is_initializing = B_FALSE;
3600 
3601         /*
3602          * Create DDTs (dedup tables).
3603          */
3604         ddt_create(spa);
3605 
3606         spa_update_dspace(spa);
3607 
3608         tx = dmu_tx_create_assigned(dp, txg);
3609 
3610         /*
3611          * Create the pool config object.
3612          */
3613         spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
3614             DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
3615             DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
3616 
3617         if (zap_add(spa->spa_meta_objset,
3618             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
3619             sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
3620                 cmn_err(CE_PANIC, "failed to add pool config");
3621         }
3622 
3623         if (spa_version(spa) >= SPA_VERSION_FEATURES)
3624                 spa_feature_create_zap_objects(spa, tx);
3625 
3626         if (zap_add(spa->spa_meta_objset,
3627             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
3628             sizeof (uint64_t), 1, &version, tx) != 0) {
3629                 cmn_err(CE_PANIC, "failed to add pool version");
3630         }
3631 
3632         /* Newly created pools with the right version are always deflated. */
3633         if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
3634                 spa->spa_deflate = TRUE;
3635                 if (zap_add(spa->spa_meta_objset,
3636                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
3637                     sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
3638                         cmn_err(CE_PANIC, "failed to add deflate");
3639                 }
3640         }
3641 
3642         /*
3643          * Create the deferred-free bpobj.  Turn off compression
3644          * because sync-to-convergence takes longer if the blocksize
3645          * keeps changing.
3646          */
3647         obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
3648         dmu_object_set_compress(spa->spa_meta_objset, obj,
3649             ZIO_COMPRESS_OFF, tx);
3650         if (zap_add(spa->spa_meta_objset,
3651             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
3652             sizeof (uint64_t), 1, &obj, tx) != 0) {
3653                 cmn_err(CE_PANIC, "failed to add bpobj");
3654         }
3655         VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
3656             spa->spa_meta_objset, obj));
3657 
3658         /*
3659          * Create the pool's history object.
3660          */
3661         if (version >= SPA_VERSION_ZPOOL_HISTORY)
3662                 spa_history_create_obj(spa, tx);
3663 
3664         /*
3665          * Set pool properties.
3666          */
3667         spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
3668         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
3669         spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
3670         spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
3671 
3672         if (props != NULL) {
3673                 spa_configfile_set(spa, props, B_FALSE);
3674                 spa_sync_props(props, tx);
3675         }
3676 
3677         dmu_tx_commit(tx);
3678 
3679         spa->spa_sync_on = B_TRUE;
3680         txg_sync_start(spa->spa_dsl_pool);
3681 
3682         /*
3683          * We explicitly wait for the first transaction to complete so that our
3684          * bean counters are appropriately updated.
3685          */
3686         txg_wait_synced(spa->spa_dsl_pool, txg);
3687 
3688         spa_config_sync(spa, B_FALSE, B_TRUE);
3689 
3690         spa_history_log_version(spa, "create");
3691 
3692         /*
3693          * Don't count references from objsets that are already closed
3694          * and are making their way through the eviction process.
3695          */
3696         spa_evicting_os_wait(spa);
3697         spa->spa_minref = refcount_count(&spa->spa_refcount);
3698 
3699         mutex_exit(&spa_namespace_lock);
3700 
3701         return (0);
3702 }
3703 
3704 #ifdef _KERNEL
3705 /*
3706  * Get the root pool information from the root disk, then import the root pool
3707  * during the system boot up time.
3708  */
3709 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
3710 
3711 static nvlist_t *
3712 spa_generate_rootconf(char *devpath, char *devid, uint64_t *guid)
3713 {
3714         nvlist_t *config;
3715         nvlist_t *nvtop, *nvroot;
3716         uint64_t pgid;
3717 
3718         if (vdev_disk_read_rootlabel(devpath, devid, &config) != 0)
3719                 return (NULL);
3720 
3721         /*
3722          * Add this top-level vdev to the child array.
3723          */
3724         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3725             &nvtop) == 0);
3726         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
3727             &pgid) == 0);
3728         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, guid) == 0);
3729 
3730         /*
3731          * Put this pool's top-level vdevs into a root vdev.
3732          */
3733         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3734         VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
3735             VDEV_TYPE_ROOT) == 0);
3736         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
3737         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
3738         VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
3739             &nvtop, 1) == 0);
3740 
3741         /*
3742          * Replace the existing vdev_tree with the new root vdev in
3743          * this pool's configuration (remove the old, add the new).
3744          */
3745         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
3746         nvlist_free(nvroot);
3747         return (config);
3748 }
3749 
3750 /*
3751  * Walk the vdev tree and see if we can find a device with "better"
3752  * configuration. A configuration is "better" if the label on that
3753  * device has a more recent txg.
3754  */
3755 static void
3756 spa_alt_rootvdev(vdev_t *vd, vdev_t **avd, uint64_t *txg)
3757 {
3758         for (int c = 0; c < vd->vdev_children; c++)
3759                 spa_alt_rootvdev(vd->vdev_child[c], avd, txg);
3760 
3761         if (vd->vdev_ops->vdev_op_leaf) {
3762                 nvlist_t *label;
3763                 uint64_t label_txg;
3764 
3765                 if (vdev_disk_read_rootlabel(vd->vdev_physpath, vd->vdev_devid,
3766                     &label) != 0)
3767                         return;
3768 
3769                 VERIFY(nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
3770                     &label_txg) == 0);
3771 
3772                 /*
3773                  * Do we have a better boot device?
3774                  */
3775                 if (label_txg > *txg) {
3776                         *txg = label_txg;
3777                         *avd = vd;
3778                 }
3779                 nvlist_free(label);
3780         }
3781 }
3782 
3783 /*
3784  * Import a root pool.
3785  *
3786  * For x86. devpath_list will consist of devid and/or physpath name of
3787  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
3788  * The GRUB "findroot" command will return the vdev we should boot.
3789  *
3790  * For Sparc, devpath_list consists the physpath name of the booting device
3791  * no matter the rootpool is a single device pool or a mirrored pool.
3792  * e.g.
3793  *      "/pci@1f,0/ide@d/disk@0,0:a"
3794  */
3795 int
3796 spa_import_rootpool(char *devpath, char *devid)
3797 {
3798         spa_t *spa;
3799         vdev_t *rvd, *bvd, *avd = NULL;
3800         nvlist_t *config, *nvtop;
3801         uint64_t guid, txg;
3802         char *pname;
3803         int error;
3804 
3805         /*
3806          * Read the label from the boot device and generate a configuration.
3807          */
3808         config = spa_generate_rootconf(devpath, devid, &guid);
3809 #if defined(_OBP) && defined(_KERNEL)
3810         if (config == NULL) {
3811                 if (strstr(devpath, "/iscsi/ssd") != NULL) {
3812                         /* iscsi boot */
3813                         get_iscsi_bootpath_phy(devpath);
3814                         config = spa_generate_rootconf(devpath, devid, &guid);
3815                 }
3816         }
3817 #endif
3818         if (config == NULL) {
3819                 cmn_err(CE_NOTE, "Cannot read the pool label from '%s'",
3820                     devpath);
3821                 return (SET_ERROR(EIO));
3822         }
3823 
3824         VERIFY(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
3825             &pname) == 0);
3826         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
3827 
3828         mutex_enter(&spa_namespace_lock);
3829         if ((spa = spa_lookup(pname)) != NULL) {
3830                 /*
3831                  * Remove the existing root pool from the namespace so that we
3832                  * can replace it with the correct config we just read in.
3833                  */
3834                 spa_remove(spa);
3835         }
3836 
3837         spa = spa_add(pname, config, NULL);
3838         spa->spa_is_root = B_TRUE;
3839         spa->spa_import_flags = ZFS_IMPORT_VERBATIM;
3840 
3841         /*
3842          * Build up a vdev tree based on the boot device's label config.
3843          */
3844         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3845             &nvtop) == 0);
3846         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3847         error = spa_config_parse(spa, &rvd, nvtop, NULL, 0,
3848             VDEV_ALLOC_ROOTPOOL);
3849         spa_config_exit(spa, SCL_ALL, FTAG);
3850         if (error) {
3851                 mutex_exit(&spa_namespace_lock);
3852                 nvlist_free(config);
3853                 cmn_err(CE_NOTE, "Can not parse the config for pool '%s'",
3854                     pname);
3855                 return (error);
3856         }
3857 
3858         /*
3859          * Get the boot vdev.
3860          */
3861         if ((bvd = vdev_lookup_by_guid(rvd, guid)) == NULL) {
3862                 cmn_err(CE_NOTE, "Can not find the boot vdev for guid %llu",
3863                     (u_longlong_t)guid);
3864                 error = SET_ERROR(ENOENT);
3865                 goto out;
3866         }
3867 
3868         /*
3869          * Determine if there is a better boot device.
3870          */
3871         avd = bvd;
3872         spa_alt_rootvdev(rvd, &avd, &txg);
3873         if (avd != bvd) {
3874                 cmn_err(CE_NOTE, "The boot device is 'degraded'. Please "
3875                     "try booting from '%s'", avd->vdev_path);
3876                 error = SET_ERROR(EINVAL);
3877                 goto out;
3878         }
3879 
3880         /*
3881          * If the boot device is part of a spare vdev then ensure that
3882          * we're booting off the active spare.
3883          */
3884         if (bvd->vdev_parent->vdev_ops == &vdev_spare_ops &&
3885             !bvd->vdev_isspare) {
3886                 cmn_err(CE_NOTE, "The boot device is currently spared. Please "
3887                     "try booting from '%s'",
3888                     bvd->vdev_parent->
3889                     vdev_child[bvd->vdev_parent->vdev_children - 1]->vdev_path);
3890                 error = SET_ERROR(EINVAL);
3891                 goto out;
3892         }
3893 
3894         error = 0;
3895 out:
3896         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3897         vdev_free(rvd);
3898         spa_config_exit(spa, SCL_ALL, FTAG);
3899         mutex_exit(&spa_namespace_lock);
3900 
3901         nvlist_free(config);
3902         return (error);
3903 }
3904 
3905 #endif
3906 
3907 /*
3908  * Import a non-root pool into the system.
3909  */
3910 int
3911 spa_import(const char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
3912 {
3913         spa_t *spa;
3914         char *altroot = NULL;
3915         spa_load_state_t state = SPA_LOAD_IMPORT;
3916         zpool_rewind_policy_t policy;
3917         uint64_t mode = spa_mode_global;
3918         uint64_t readonly = B_FALSE;
3919         int error;
3920         nvlist_t *nvroot;
3921         nvlist_t **spares, **l2cache;
3922         uint_t nspares, nl2cache;
3923 
3924         /*
3925          * If a pool with this name exists, return failure.
3926          */
3927         mutex_enter(&spa_namespace_lock);
3928         if (spa_lookup(pool) != NULL) {
3929                 mutex_exit(&spa_namespace_lock);
3930                 return (SET_ERROR(EEXIST));
3931         }
3932 
3933         /*
3934          * Create and initialize the spa structure.
3935          */
3936         (void) nvlist_lookup_string(props,
3937             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3938         (void) nvlist_lookup_uint64(props,
3939             zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
3940         if (readonly)
3941                 mode = FREAD;
3942         spa = spa_add(pool, config, altroot);
3943         spa->spa_import_flags = flags;
3944 
3945         /*
3946          * Verbatim import - Take a pool and insert it into the namespace
3947          * as if it had been loaded at boot.
3948          */
3949         if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
3950                 if (props != NULL)
3951                         spa_configfile_set(spa, props, B_FALSE);
3952 
3953                 spa_config_sync(spa, B_FALSE, B_TRUE);
3954 
3955                 mutex_exit(&spa_namespace_lock);
3956                 return (0);
3957         }
3958 
3959         spa_activate(spa, mode);
3960 
3961         /*
3962          * Don't start async tasks until we know everything is healthy.
3963          */
3964         spa_async_suspend(spa);
3965 
3966         zpool_get_rewind_policy(config, &policy);
3967         if (policy.zrp_request & ZPOOL_DO_REWIND)
3968                 state = SPA_LOAD_RECOVER;
3969 
3970         /*
3971          * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
3972          * because the user-supplied config is actually the one to trust when
3973          * doing an import.
3974          */
3975         if (state != SPA_LOAD_RECOVER)
3976                 spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
3977 
3978         error = spa_load_best(spa, state, B_TRUE, policy.zrp_txg,
3979             policy.zrp_request);
3980 
3981         /*
3982          * Propagate anything learned while loading the pool and pass it
3983          * back to caller (i.e. rewind info, missing devices, etc).
3984          */
3985         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
3986             spa->spa_load_info) == 0);
3987 
3988         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3989         /*
3990          * Toss any existing sparelist, as it doesn't have any validity
3991          * anymore, and conflicts with spa_has_spare().
3992          */
3993         if (spa->spa_spares.sav_config) {
3994                 nvlist_free(spa->spa_spares.sav_config);
3995                 spa->spa_spares.sav_config = NULL;
3996                 spa_load_spares(spa);
3997         }
3998         if (spa->spa_l2cache.sav_config) {
3999                 nvlist_free(spa->spa_l2cache.sav_config);
4000                 spa->spa_l2cache.sav_config = NULL;
4001                 spa_load_l2cache(spa);
4002         }
4003 
4004         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
4005             &nvroot) == 0);
4006         if (error == 0)
4007                 error = spa_validate_aux(spa, nvroot, -1ULL,
4008                     VDEV_ALLOC_SPARE);
4009         if (error == 0)
4010                 error = spa_validate_aux(spa, nvroot, -1ULL,
4011                     VDEV_ALLOC_L2CACHE);
4012         spa_config_exit(spa, SCL_ALL, FTAG);
4013 
4014         if (props != NULL)
4015                 spa_configfile_set(spa, props, B_FALSE);
4016 
4017         if (error != 0 || (props && spa_writeable(spa) &&
4018             (error = spa_prop_set(spa, props)))) {
4019                 spa_unload(spa);
4020                 spa_deactivate(spa);
4021                 spa_remove(spa);
4022                 mutex_exit(&spa_namespace_lock);
4023                 return (error);
4024         }
4025 
4026         spa_async_resume(spa);
4027 
4028         /*
4029          * Override any spares and level 2 cache devices as specified by
4030          * the user, as these may have correct device names/devids, etc.
4031          */
4032         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
4033             &spares, &nspares) == 0) {
4034                 if (spa->spa_spares.sav_config)
4035                         VERIFY(nvlist_remove(spa->spa_spares.sav_config,
4036                             ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
4037                 else
4038                         VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
4039                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
4040                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
4041                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
4042                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4043                 spa_load_spares(spa);
4044                 spa_config_exit(spa, SCL_ALL, FTAG);
4045                 spa->spa_spares.sav_sync = B_TRUE;
4046         }
4047         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
4048             &l2cache, &nl2cache) == 0) {
4049                 if (spa->spa_l2cache.sav_config)
4050                         VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
4051                             ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
4052                 else
4053                         VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
4054                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
4055                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
4056                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
4057                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4058                 spa_load_l2cache(spa);
4059                 spa_config_exit(spa, SCL_ALL, FTAG);
4060                 spa->spa_l2cache.sav_sync = B_TRUE;
4061         }
4062 
4063         /*
4064          * Check for any removed devices.
4065          */
4066         if (spa->spa_autoreplace) {
4067                 spa_aux_check_removed(&spa->spa_spares);
4068                 spa_aux_check_removed(&spa->spa_l2cache);
4069         }
4070 
4071         if (spa_writeable(spa)) {
4072                 /*
4073                  * Update the config cache to include the newly-imported pool.
4074                  */
4075                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4076         }
4077 
4078         /*
4079          * It's possible that the pool was expanded while it was exported.
4080          * We kick off an async task to handle this for us.
4081          */
4082         spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
4083 
4084         mutex_exit(&spa_namespace_lock);
4085         spa_history_log_version(spa, "import");
4086 
4087         return (0);
4088 }
4089 
4090 nvlist_t *
4091 spa_tryimport(nvlist_t *tryconfig)
4092 {
4093         nvlist_t *config = NULL;
4094         char *poolname;
4095         spa_t *spa;
4096         uint64_t state;
4097         int error;
4098 
4099         if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
4100                 return (NULL);
4101 
4102         if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
4103                 return (NULL);
4104 
4105         /*
4106          * Create and initialize the spa structure.
4107          */
4108         mutex_enter(&spa_namespace_lock);
4109         spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
4110         spa_activate(spa, FREAD);
4111 
4112         /*
4113          * Pass off the heavy lifting to spa_load().
4114          * Pass TRUE for mosconfig because the user-supplied config
4115          * is actually the one to trust when doing an import.
4116          */
4117         error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING, B_TRUE);
4118 
4119         /*
4120          * If 'tryconfig' was at least parsable, return the current config.
4121          */
4122         if (spa->spa_root_vdev != NULL) {
4123                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
4124                 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
4125                     poolname) == 0);
4126                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4127                     state) == 0);
4128                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
4129                     spa->spa_uberblock.ub_timestamp) == 0);
4130                 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
4131                     spa->spa_load_info) == 0);
4132 
4133                 /*
4134                  * If the bootfs property exists on this pool then we
4135                  * copy it out so that external consumers can tell which
4136                  * pools are bootable.
4137                  */
4138                 if ((!error || error == EEXIST) && spa->spa_bootfs) {
4139                         char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4140 
4141                         /*
4142                          * We have to play games with the name since the
4143                          * pool was opened as TRYIMPORT_NAME.
4144                          */
4145                         if (dsl_dsobj_to_dsname(spa_name(spa),
4146                             spa->spa_bootfs, tmpname) == 0) {
4147                                 char *cp;
4148                                 char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4149 
4150                                 cp = strchr(tmpname, '/');
4151                                 if (cp == NULL) {
4152                                         (void) strlcpy(dsname, tmpname,
4153                                             MAXPATHLEN);
4154                                 } else {
4155                                         (void) snprintf(dsname, MAXPATHLEN,
4156                                             "%s/%s", poolname, ++cp);
4157                                 }
4158                                 VERIFY(nvlist_add_string(config,
4159                                     ZPOOL_CONFIG_BOOTFS, dsname) == 0);
4160                                 kmem_free(dsname, MAXPATHLEN);
4161                         }
4162                         kmem_free(tmpname, MAXPATHLEN);
4163                 }
4164 
4165                 /*
4166                  * Add the list of hot spares and level 2 cache devices.
4167                  */
4168                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
4169                 spa_add_spares(spa, config);
4170                 spa_add_l2cache(spa, config);
4171                 spa_config_exit(spa, SCL_CONFIG, FTAG);
4172         }
4173 
4174         spa_unload(spa);
4175         spa_deactivate(spa);
4176         spa_remove(spa);
4177         mutex_exit(&spa_namespace_lock);
4178 
4179         return (config);
4180 }
4181 
4182 /*
4183  * Pool export/destroy
4184  *
4185  * The act of destroying or exporting a pool is very simple.  We make sure there
4186  * is no more pending I/O and any references to the pool are gone.  Then, we
4187  * update the pool state and sync all the labels to disk, removing the
4188  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
4189  * we don't sync the labels or remove the configuration cache.
4190  */
4191 static int
4192 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
4193     boolean_t force, boolean_t hardforce)
4194 {
4195         spa_t *spa;
4196 
4197         if (oldconfig)
4198                 *oldconfig = NULL;
4199 
4200         if (!(spa_mode_global & FWRITE))
4201                 return (SET_ERROR(EROFS));
4202 
4203         mutex_enter(&spa_namespace_lock);
4204         if ((spa = spa_lookup(pool)) == NULL) {
4205                 mutex_exit(&spa_namespace_lock);
4206                 return (SET_ERROR(ENOENT));
4207         }
4208 
4209         /*
4210          * Put a hold on the pool, drop the namespace lock, stop async tasks,
4211          * reacquire the namespace lock, and see if we can export.
4212          */
4213         spa_open_ref(spa, FTAG);
4214         mutex_exit(&spa_namespace_lock);
4215         spa_async_suspend(spa);
4216         mutex_enter(&spa_namespace_lock);
4217         spa_close(spa, FTAG);
4218 
4219         /*
4220          * The pool will be in core if it's openable,
4221          * in which case we can modify its state.
4222          */
4223         if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
4224                 /*
4225                  * Objsets may be open only because they're dirty, so we
4226                  * have to force it to sync before checking spa_refcnt.
4227                  */
4228                 txg_wait_synced(spa->spa_dsl_pool, 0);
4229                 spa_evicting_os_wait(spa);
4230 
4231                 /*
4232                  * A pool cannot be exported or destroyed if there are active
4233                  * references.  If we are resetting a pool, allow references by
4234                  * fault injection handlers.
4235                  */
4236                 if (!spa_refcount_zero(spa) ||
4237                     (spa->spa_inject_ref != 0 &&
4238                     new_state != POOL_STATE_UNINITIALIZED)) {
4239                         spa_async_resume(spa);
4240                         mutex_exit(&spa_namespace_lock);
4241                         return (SET_ERROR(EBUSY));
4242                 }
4243 
4244                 /*
4245                  * A pool cannot be exported if it has an active shared spare.
4246                  * This is to prevent other pools stealing the active spare
4247                  * from an exported pool. At user's own will, such pool can
4248                  * be forcedly exported.
4249                  */
4250                 if (!force && new_state == POOL_STATE_EXPORTED &&
4251                     spa_has_active_shared_spare(spa)) {
4252                         spa_async_resume(spa);
4253                         mutex_exit(&spa_namespace_lock);
4254                         return (SET_ERROR(EXDEV));
4255                 }
4256 
4257                 /*
4258                  * We want this to be reflected on every label,
4259                  * so mark them all dirty.  spa_unload() will do the
4260                  * final sync that pushes these changes out.
4261                  */
4262                 if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
4263                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4264                         spa->spa_state = new_state;
4265                         spa->spa_final_txg = spa_last_synced_txg(spa) +
4266                             TXG_DEFER_SIZE + 1;
4267                         vdev_config_dirty(spa->spa_root_vdev);
4268                         spa_config_exit(spa, SCL_ALL, FTAG);
4269                 }
4270         }
4271 
4272         spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
4273 
4274         if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
4275                 spa_unload(spa);
4276                 spa_deactivate(spa);
4277         }
4278 
4279         if (oldconfig && spa->spa_config)
4280                 VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
4281 
4282         if (new_state != POOL_STATE_UNINITIALIZED) {
4283                 if (!hardforce)
4284                         spa_config_sync(spa, B_TRUE, B_TRUE);
4285                 spa_remove(spa);
4286         }
4287         mutex_exit(&spa_namespace_lock);
4288 
4289         return (0);
4290 }
4291 
4292 /*
4293  * Destroy a storage pool.
4294  */
4295 int
4296 spa_destroy(char *pool)
4297 {
4298         return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
4299             B_FALSE, B_FALSE));
4300 }
4301 
4302 /*
4303  * Export a storage pool.
4304  */
4305 int
4306 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
4307     boolean_t hardforce)
4308 {
4309         return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
4310             force, hardforce));
4311 }
4312 
4313 /*
4314  * Similar to spa_export(), this unloads the spa_t without actually removing it
4315  * from the namespace in any way.
4316  */
4317 int
4318 spa_reset(char *pool)
4319 {
4320         return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
4321             B_FALSE, B_FALSE));
4322 }
4323 
4324 /*
4325  * ==========================================================================
4326  * Device manipulation
4327  * ==========================================================================
4328  */
4329 
4330 /*
4331  * Add a device to a storage pool.
4332  */
4333 int
4334 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
4335 {
4336         uint64_t txg, id;
4337         int error;
4338         vdev_t *rvd = spa->spa_root_vdev;
4339         vdev_t *vd, *tvd;
4340         nvlist_t **spares, **l2cache;
4341         uint_t nspares, nl2cache;
4342 
4343         ASSERT(spa_writeable(spa));
4344 
4345         txg = spa_vdev_enter(spa);
4346 
4347         if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
4348             VDEV_ALLOC_ADD)) != 0)
4349                 return (spa_vdev_exit(spa, NULL, txg, error));
4350 
4351         spa->spa_pending_vdev = vd;  /* spa_vdev_exit() will clear this */
4352 
4353         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
4354             &nspares) != 0)
4355                 nspares = 0;
4356 
4357         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
4358             &nl2cache) != 0)
4359                 nl2cache = 0;
4360 
4361         if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
4362                 return (spa_vdev_exit(spa, vd, txg, EINVAL));
4363 
4364         if (vd->vdev_children != 0 &&
4365             (error = vdev_create(vd, txg, B_FALSE)) != 0)
4366                 return (spa_vdev_exit(spa, vd, txg, error));
4367 
4368         /*
4369          * We must validate the spares and l2cache devices after checking the
4370          * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
4371          */
4372         if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
4373                 return (spa_vdev_exit(spa, vd, txg, error));
4374 
4375         /*
4376          * Transfer each new top-level vdev from vd to rvd.
4377          */
4378         for (int c = 0; c < vd->vdev_children; c++) {
4379 
4380                 /*
4381                  * Set the vdev id to the first hole, if one exists.
4382                  */
4383                 for (id = 0; id < rvd->vdev_children; id++) {
4384                         if (rvd->vdev_child[id]->vdev_ishole) {
4385                                 vdev_free(rvd->vdev_child[id]);
4386                                 break;
4387                         }
4388                 }
4389                 tvd = vd->vdev_child[c];
4390                 vdev_remove_child(vd, tvd);
4391                 tvd->vdev_id = id;
4392                 vdev_add_child(rvd, tvd);
4393                 vdev_config_dirty(tvd);
4394         }
4395 
4396         if (nspares != 0) {
4397                 spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
4398                     ZPOOL_CONFIG_SPARES);
4399                 spa_load_spares(spa);
4400                 spa->spa_spares.sav_sync = B_TRUE;
4401         }
4402 
4403         if (nl2cache != 0) {
4404                 spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
4405                     ZPOOL_CONFIG_L2CACHE);
4406                 spa_load_l2cache(spa);
4407                 spa->spa_l2cache.sav_sync = B_TRUE;
4408         }
4409 
4410         /*
4411          * We have to be careful when adding new vdevs to an existing pool.
4412          * If other threads start allocating from these vdevs before we
4413          * sync the config cache, and we lose power, then upon reboot we may
4414          * fail to open the pool because there are DVAs that the config cache
4415          * can't translate.  Therefore, we first add the vdevs without
4416          * initializing metaslabs; sync the config cache (via spa_vdev_exit());
4417          * and then let spa_config_update() initialize the new metaslabs.
4418          *
4419          * spa_load() checks for added-but-not-initialized vdevs, so that
4420          * if we lose power at any point in this sequence, the remaining
4421          * steps will be completed the next time we load the pool.
4422          */
4423         (void) spa_vdev_exit(spa, vd, txg, 0);
4424 
4425         mutex_enter(&spa_namespace_lock);
4426         spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4427         mutex_exit(&spa_namespace_lock);
4428 
4429         return (0);
4430 }
4431 
4432 /*
4433  * Attach a device to a mirror.  The arguments are the path to any device
4434  * in the mirror, and the nvroot for the new device.  If the path specifies
4435  * a device that is not mirrored, we automatically insert the mirror vdev.
4436  *
4437  * If 'replacing' is specified, the new device is intended to replace the
4438  * existing device; in this case the two devices are made into their own
4439  * mirror using the 'replacing' vdev, which is functionally identical to
4440  * the mirror vdev (it actually reuses all the same ops) but has a few
4441  * extra rules: you can't attach to it after it's been created, and upon
4442  * completion of resilvering, the first disk (the one being replaced)
4443  * is automatically detached.
4444  */
4445 int
4446 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
4447 {
4448         uint64_t txg, dtl_max_txg;
4449         vdev_t *rvd = spa->spa_root_vdev;
4450         vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
4451         vdev_ops_t *pvops;
4452         char *oldvdpath, *newvdpath;
4453         int newvd_isspare;
4454         int error;
4455 
4456         ASSERT(spa_writeable(spa));
4457 
4458         txg = spa_vdev_enter(spa);
4459 
4460         oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
4461 
4462         if (oldvd == NULL)
4463                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4464 
4465         if (!oldvd->vdev_ops->vdev_op_leaf)
4466                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4467 
4468         pvd = oldvd->vdev_parent;
4469 
4470         if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
4471             VDEV_ALLOC_ATTACH)) != 0)
4472                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4473 
4474         if (newrootvd->vdev_children != 1)
4475                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4476 
4477         newvd = newrootvd->vdev_child[0];
4478 
4479         if (!newvd->vdev_ops->vdev_op_leaf)
4480                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4481 
4482         if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
4483                 return (spa_vdev_exit(spa, newrootvd, txg, error));
4484 
4485         /*
4486          * Spares can't replace logs
4487          */
4488         if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
4489                 return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4490 
4491         if (!replacing) {
4492                 /*
4493                  * For attach, the only allowable parent is a mirror or the root
4494                  * vdev.
4495                  */
4496                 if (pvd->vdev_ops != &vdev_mirror_ops &&
4497                     pvd->vdev_ops != &vdev_root_ops)
4498                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4499 
4500                 pvops = &vdev_mirror_ops;
4501         } else {
4502                 /*
4503                  * Active hot spares can only be replaced by inactive hot
4504                  * spares.
4505                  */
4506                 if (pvd->vdev_ops == &vdev_spare_ops &&
4507                     oldvd->vdev_isspare &&
4508                     !spa_has_spare(spa, newvd->vdev_guid))
4509                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4510 
4511                 /*
4512                  * If the source is a hot spare, and the parent isn't already a
4513                  * spare, then we want to create a new hot spare.  Otherwise, we
4514                  * want to create a replacing vdev.  The user is not allowed to
4515                  * attach to a spared vdev child unless the 'isspare' state is
4516                  * the same (spare replaces spare, non-spare replaces
4517                  * non-spare).
4518                  */
4519                 if (pvd->vdev_ops == &vdev_replacing_ops &&
4520                     spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
4521                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4522                 } else if (pvd->vdev_ops == &vdev_spare_ops &&
4523                     newvd->vdev_isspare != oldvd->vdev_isspare) {
4524                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4525                 }
4526 
4527                 if (newvd->vdev_isspare)
4528                         pvops = &vdev_spare_ops;
4529                 else
4530                         pvops = &vdev_replacing_ops;
4531         }
4532 
4533         /*
4534          * Make sure the new device is big enough.
4535          */
4536         if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
4537                 return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
4538 
4539         /*
4540          * The new device cannot have a higher alignment requirement
4541          * than the top-level vdev.
4542          */
4543         if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
4544                 return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
4545 
4546         /*
4547          * If this is an in-place replacement, update oldvd's path and devid
4548          * to make it distinguishable from newvd, and unopenable from now on.
4549          */
4550         if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
4551                 spa_strfree(oldvd->vdev_path);
4552                 oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
4553                     KM_SLEEP);
4554                 (void) sprintf(oldvd->vdev_path, "%s/%s",
4555                     newvd->vdev_path, "old");
4556                 if (oldvd->vdev_devid != NULL) {
4557                         spa_strfree(oldvd->vdev_devid);
4558                         oldvd->vdev_devid = NULL;
4559                 }
4560         }
4561 
4562         /* mark the device being resilvered */
4563         newvd->vdev_resilver_txg = txg;
4564 
4565         /*
4566          * If the parent is not a mirror, or if we're replacing, insert the new
4567          * mirror/replacing/spare vdev above oldvd.
4568          */
4569         if (pvd->vdev_ops != pvops)
4570                 pvd = vdev_add_parent(oldvd, pvops);
4571 
4572         ASSERT(pvd->vdev_top->vdev_parent == rvd);
4573         ASSERT(pvd->vdev_ops == pvops);
4574         ASSERT(oldvd->vdev_parent == pvd);
4575 
4576         /*
4577          * Extract the new device from its root and add it to pvd.
4578          */
4579         vdev_remove_child(newrootvd, newvd);
4580         newvd->vdev_id = pvd->vdev_children;
4581         newvd->vdev_crtxg = oldvd->vdev_crtxg;
4582         vdev_add_child(pvd, newvd);
4583 
4584         tvd = newvd->vdev_top;
4585         ASSERT(pvd->vdev_top == tvd);
4586         ASSERT(tvd->vdev_parent == rvd);
4587 
4588         vdev_config_dirty(tvd);
4589 
4590         /*
4591          * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
4592          * for any dmu_sync-ed blocks.  It will propagate upward when
4593          * spa_vdev_exit() calls vdev_dtl_reassess().
4594          */
4595         dtl_max_txg = txg + TXG_CONCURRENT_STATES;
4596 
4597         vdev_dtl_dirty(newvd, DTL_MISSING, TXG_INITIAL,
4598             dtl_max_txg - TXG_INITIAL);
4599 
4600         if (newvd->vdev_isspare) {
4601                 spa_spare_activate(newvd);
4602                 spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
4603         }
4604 
4605         oldvdpath = spa_strdup(oldvd->vdev_path);
4606         newvdpath = spa_strdup(newvd->vdev_path);
4607         newvd_isspare = newvd->vdev_isspare;
4608 
4609         /*
4610          * Mark newvd's DTL dirty in this txg.
4611          */
4612         vdev_dirty(tvd, VDD_DTL, newvd, txg);
4613 
4614         /*
4615          * Schedule the resilver to restart in the future. We do this to
4616          * ensure that dmu_sync-ed blocks have been stitched into the
4617          * respective datasets.
4618          */
4619         dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
4620 
4621         /*
4622          * Commit the config
4623          */
4624         (void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
4625 
4626         spa_history_log_internal(spa, "vdev attach", NULL,
4627             "%s vdev=%s %s vdev=%s",
4628             replacing && newvd_isspare ? "spare in" :
4629             replacing ? "replace" : "attach", newvdpath,
4630             replacing ? "for" : "to", oldvdpath);
4631 
4632         spa_strfree(oldvdpath);
4633         spa_strfree(newvdpath);
4634 
4635         if (spa->spa_bootfs)
4636                 spa_event_notify(spa, newvd, ESC_ZFS_BOOTFS_VDEV_ATTACH);
4637 
4638         return (0);
4639 }
4640 
4641 /*
4642  * Detach a device from a mirror or replacing vdev.
4643  *
4644  * If 'replace_done' is specified, only detach if the parent
4645  * is a replacing vdev.
4646  */
4647 int
4648 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
4649 {
4650         uint64_t txg;
4651         int error;
4652         vdev_t *rvd = spa->spa_root_vdev;
4653         vdev_t *vd, *pvd, *cvd, *tvd;
4654         boolean_t unspare = B_FALSE;
4655         uint64_t unspare_guid = 0;
4656         char *vdpath;
4657 
4658         ASSERT(spa_writeable(spa));
4659 
4660         txg = spa_vdev_enter(spa);
4661 
4662         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4663 
4664         if (vd == NULL)
4665                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4666 
4667         if (!vd->vdev_ops->vdev_op_leaf)
4668                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4669 
4670         pvd = vd->vdev_parent;
4671 
4672         /*
4673          * If the parent/child relationship is not as expected, don't do it.
4674          * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
4675          * vdev that's replacing B with C.  The user's intent in replacing
4676          * is to go from M(A,B) to M(A,C).  If the user decides to cancel
4677          * the replace by detaching C, the expected behavior is to end up
4678          * M(A,B).  But suppose that right after deciding to detach C,
4679          * the replacement of B completes.  We would have M(A,C), and then
4680          * ask to detach C, which would leave us with just A -- not what
4681          * the user wanted.  To prevent this, we make sure that the
4682          * parent/child relationship hasn't changed -- in this example,
4683          * that C's parent is still the replacing vdev R.
4684          */
4685         if (pvd->vdev_guid != pguid && pguid != 0)
4686                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4687 
4688         /*
4689          * Only 'replacing' or 'spare' vdevs can be replaced.
4690          */
4691         if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
4692             pvd->vdev_ops != &vdev_spare_ops)
4693                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4694 
4695         ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
4696             spa_version(spa) >= SPA_VERSION_SPARES);
4697 
4698         /*
4699          * Only mirror, replacing, and spare vdevs support detach.
4700          */
4701         if (pvd->vdev_ops != &vdev_replacing_ops &&
4702             pvd->vdev_ops != &vdev_mirror_ops &&
4703             pvd->vdev_ops != &vdev_spare_ops)
4704                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4705 
4706         /*
4707          * If this device has the only valid copy of some data,
4708          * we cannot safely detach it.
4709          */
4710         if (vdev_dtl_required(vd))
4711                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4712 
4713         ASSERT(pvd->vdev_children >= 2);
4714 
4715         /*
4716          * If we are detaching the second disk from a replacing vdev, then
4717          * check to see if we changed the original vdev's path to have "/old"
4718          * at the end in spa_vdev_attach().  If so, undo that change now.
4719          */
4720         if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
4721             vd->vdev_path != NULL) {
4722                 size_t len = strlen(vd->vdev_path);
4723 
4724                 for (int c = 0; c < pvd->vdev_children; c++) {
4725                         cvd = pvd->vdev_child[c];
4726 
4727                         if (cvd == vd || cvd->vdev_path == NULL)
4728                                 continue;
4729 
4730                         if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
4731                             strcmp(cvd->vdev_path + len, "/old") == 0) {
4732                                 spa_strfree(cvd->vdev_path);
4733                                 cvd->vdev_path = spa_strdup(vd->vdev_path);
4734                                 break;
4735                         }
4736                 }
4737         }
4738 
4739         /*
4740          * If we are detaching the original disk from a spare, then it implies
4741          * that the spare should become a real disk, and be removed from the
4742          * active spare list for the pool.
4743          */
4744         if (pvd->vdev_ops == &vdev_spare_ops &&
4745             vd->vdev_id == 0 &&
4746             pvd->vdev_child[pvd->vdev_children - 1]->vdev_isspare)
4747                 unspare = B_TRUE;
4748 
4749         /*
4750          * Erase the disk labels so the disk can be used for other things.
4751          * This must be done after all other error cases are handled,
4752          * but before we disembowel vd (so we can still do I/O to it).
4753          * But if we can't do it, don't treat the error as fatal --
4754          * it may be that the unwritability of the disk is the reason
4755          * it's being detached!
4756          */
4757         error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4758 
4759         /*
4760          * Remove vd from its parent and compact the parent's children.
4761          */
4762         vdev_remove_child(pvd, vd);
4763         vdev_compact_children(pvd);
4764 
4765         /*
4766          * Remember one of the remaining children so we can get tvd below.
4767          */
4768         cvd = pvd->vdev_child[pvd->vdev_children - 1];
4769 
4770         /*
4771          * If we need to remove the remaining child from the list of hot spares,
4772          * do it now, marking the vdev as no longer a spare in the process.
4773          * We must do this before vdev_remove_parent(), because that can
4774          * change the GUID if it creates a new toplevel GUID.  For a similar
4775          * reason, we must remove the spare now, in the same txg as the detach;
4776          * otherwise someone could attach a new sibling, change the GUID, and
4777          * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
4778          */
4779         if (unspare) {
4780                 ASSERT(cvd->vdev_isspare);
4781                 spa_spare_remove(cvd);
4782                 unspare_guid = cvd->vdev_guid;
4783                 (void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
4784                 cvd->vdev_unspare = B_TRUE;
4785         }
4786 
4787         /*
4788          * If the parent mirror/replacing vdev only has one child,
4789          * the parent is no longer needed.  Remove it from the tree.
4790          */
4791         if (pvd->vdev_children == 1) {
4792                 if (pvd->vdev_ops == &vdev_spare_ops)
4793                         cvd->vdev_unspare = B_FALSE;
4794                 vdev_remove_parent(cvd);
4795         }
4796 
4797 
4798         /*
4799          * We don't set tvd until now because the parent we just removed
4800          * may have been the previous top-level vdev.
4801          */
4802         tvd = cvd->vdev_top;
4803         ASSERT(tvd->vdev_parent == rvd);
4804 
4805         /*
4806          * Reevaluate the parent vdev state.
4807          */
4808         vdev_propagate_state(cvd);
4809 
4810         /*
4811          * If the 'autoexpand' property is set on the pool then automatically
4812          * try to expand the size of the pool. For example if the device we
4813          * just detached was smaller than the others, it may be possible to
4814          * add metaslabs (i.e. grow the pool). We need to reopen the vdev
4815          * first so that we can obtain the updated sizes of the leaf vdevs.
4816          */
4817         if (spa->spa_autoexpand) {
4818                 vdev_reopen(tvd);
4819                 vdev_expand(tvd, txg);
4820         }
4821 
4822         vdev_config_dirty(tvd);
4823 
4824         /*
4825          * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
4826          * vd->vdev_detached is set and free vd's DTL object in syncing context.
4827          * But first make sure we're not on any *other* txg's DTL list, to
4828          * prevent vd from being accessed after it's freed.
4829          */
4830         vdpath = spa_strdup(vd->vdev_path);
4831         for (int t = 0; t < TXG_SIZE; t++)
4832                 (void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
4833         vd->vdev_detached = B_TRUE;
4834         vdev_dirty(tvd, VDD_DTL, vd, txg);
4835 
4836         spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
4837 
4838         /* hang on to the spa before we release the lock */
4839         spa_open_ref(spa, FTAG);
4840 
4841         error = spa_vdev_exit(spa, vd, txg, 0);
4842 
4843         spa_history_log_internal(spa, "detach", NULL,
4844             "vdev=%s", vdpath);
4845         spa_strfree(vdpath);
4846 
4847         /*
4848          * If this was the removal of the original device in a hot spare vdev,
4849          * then we want to go through and remove the device from the hot spare
4850          * list of every other pool.
4851          */
4852         if (unspare) {
4853                 spa_t *altspa = NULL;
4854 
4855                 mutex_enter(&spa_namespace_lock);
4856                 while ((altspa = spa_next(altspa)) != NULL) {
4857                         if (altspa->spa_state != POOL_STATE_ACTIVE ||
4858                             altspa == spa)
4859                                 continue;
4860 
4861                         spa_open_ref(altspa, FTAG);
4862                         mutex_exit(&spa_namespace_lock);
4863                         (void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
4864                         mutex_enter(&spa_namespace_lock);
4865                         spa_close(altspa, FTAG);
4866                 }
4867                 mutex_exit(&spa_namespace_lock);
4868 
4869                 /* search the rest of the vdevs for spares to remove */
4870                 spa_vdev_resilver_done(spa);
4871         }
4872 
4873         /* all done with the spa; OK to release */
4874         mutex_enter(&spa_namespace_lock);
4875         spa_close(spa, FTAG);
4876         mutex_exit(&spa_namespace_lock);
4877 
4878         return (error);
4879 }
4880 
4881 /*
4882  * Split a set of devices from their mirrors, and create a new pool from them.
4883  */
4884 int
4885 spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
4886     nvlist_t *props, boolean_t exp)
4887 {
4888         int error = 0;
4889         uint64_t txg, *glist;
4890         spa_t *newspa;
4891         uint_t c, children, lastlog;
4892         nvlist_t **child, *nvl, *tmp;
4893         dmu_tx_t *tx;
4894         char *altroot = NULL;
4895         vdev_t *rvd, **vml = NULL;                      /* vdev modify list */
4896         boolean_t activate_slog;
4897 
4898         ASSERT(spa_writeable(spa));
4899 
4900         txg = spa_vdev_enter(spa);
4901 
4902         /* clear the log and flush everything up to now */
4903         activate_slog = spa_passivate_log(spa);
4904         (void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4905         error = spa_offline_log(spa);
4906         txg = spa_vdev_config_enter(spa);
4907 
4908         if (activate_slog)
4909                 spa_activate_log(spa);
4910 
4911         if (error != 0)
4912                 return (spa_vdev_exit(spa, NULL, txg, error));
4913 
4914         /* check new spa name before going any further */
4915         if (spa_lookup(newname) != NULL)
4916                 return (spa_vdev_exit(spa, NULL, txg, EEXIST));
4917 
4918         /*
4919          * scan through all the children to ensure they're all mirrors
4920          */
4921         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
4922             nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
4923             &children) != 0)
4924                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4925 
4926         /* first, check to ensure we've got the right child count */
4927         rvd = spa->spa_root_vdev;
4928         lastlog = 0;
4929         for (c = 0; c < rvd->vdev_children; c++) {
4930                 vdev_t *vd = rvd->vdev_child[c];
4931 
4932                 /* don't count the holes & logs as children */
4933                 if (vd->vdev_islog || vd->vdev_ishole) {
4934                         if (lastlog == 0)
4935                                 lastlog = c;
4936                         continue;
4937                 }
4938 
4939                 lastlog = 0;
4940         }
4941         if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
4942                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4943 
4944         /* next, ensure no spare or cache devices are part of the split */
4945         if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
4946             nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
4947                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4948 
4949         vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
4950         glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
4951 
4952         /* then, loop over each vdev and validate it */
4953         for (c = 0; c < children; c++) {
4954                 uint64_t is_hole = 0;
4955 
4956                 (void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
4957                     &is_hole);
4958 
4959                 if (is_hole != 0) {
4960                         if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
4961                             spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
4962                                 continue;
4963                         } else {
4964                                 error = SET_ERROR(EINVAL);
4965                                 break;
4966                         }
4967                 }
4968 
4969                 /* which disk is going to be split? */
4970                 if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
4971                     &glist[c]) != 0) {
4972                         error = SET_ERROR(EINVAL);
4973                         break;
4974                 }
4975 
4976                 /* look it up in the spa */
4977                 vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
4978                 if (vml[c] == NULL) {
4979                         error = SET_ERROR(ENODEV);
4980                         break;
4981                 }
4982 
4983                 /* make sure there's nothing stopping the split */
4984                 if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
4985                     vml[c]->vdev_islog ||
4986                     vml[c]->vdev_ishole ||
4987                     vml[c]->vdev_isspare ||
4988                     vml[c]->vdev_isl2cache ||
4989                     !vdev_writeable(vml[c]) ||
4990                     vml[c]->vdev_children != 0 ||
4991                     vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
4992                     c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
4993                         error = SET_ERROR(EINVAL);
4994                         break;
4995                 }
4996 
4997                 if (vdev_dtl_required(vml[c])) {
4998                         error = SET_ERROR(EBUSY);
4999                         break;
5000                 }
5001 
5002                 /* we need certain info from the top level */
5003                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
5004                     vml[c]->vdev_top->vdev_ms_array) == 0);
5005                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
5006                     vml[c]->vdev_top->vdev_ms_shift) == 0);
5007                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
5008                     vml[c]->vdev_top->vdev_asize) == 0);
5009                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
5010                     vml[c]->vdev_top->vdev_ashift) == 0);
5011         }
5012 
5013         if (error != 0) {
5014                 kmem_free(vml, children * sizeof (vdev_t *));
5015                 kmem_free(glist, children * sizeof (uint64_t));
5016                 return (spa_vdev_exit(spa, NULL, txg, error));
5017         }
5018 
5019         /* stop writers from using the disks */
5020         for (c = 0; c < children; c++) {
5021                 if (vml[c] != NULL)
5022                         vml[c]->vdev_offline = B_TRUE;
5023         }
5024         vdev_reopen(spa->spa_root_vdev);
5025 
5026         /*
5027          * Temporarily record the splitting vdevs in the spa config.  This
5028          * will disappear once the config is regenerated.
5029          */
5030         VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5031         VERIFY(nvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
5032             glist, children) == 0);
5033         kmem_free(glist, children * sizeof (uint64_t));
5034 
5035         mutex_enter(&spa->spa_props_lock);
5036         VERIFY(nvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT,
5037             nvl) == 0);
5038         mutex_exit(&spa->spa_props_lock);
5039         spa->spa_config_splitting = nvl;
5040         vdev_config_dirty(spa->spa_root_vdev);
5041 
5042         /* configure and create the new pool */
5043         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname) == 0);
5044         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
5045             exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE) == 0);
5046         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
5047             spa_version(spa)) == 0);
5048         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
5049             spa->spa_config_txg) == 0);
5050         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
5051             spa_generate_guid(NULL)) == 0);
5052         (void) nvlist_lookup_string(props,
5053             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
5054 
5055         /* add the new pool to the namespace */
5056         newspa = spa_add(newname, config, altroot);
5057         newspa->spa_config_txg = spa->spa_config_txg;
5058         spa_set_log_state(newspa, SPA_LOG_CLEAR);
5059 
5060         /* release the spa config lock, retaining the namespace lock */
5061         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
5062 
5063         if (zio_injection_enabled)
5064                 zio_handle_panic_injection(spa, FTAG, 1);
5065 
5066         spa_activate(newspa, spa_mode_global);
5067         spa_async_suspend(newspa);
5068 
5069         /* create the new pool from the disks of the original pool */
5070         error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE, B_TRUE);
5071         if (error)
5072                 goto out;
5073 
5074         /* if that worked, generate a real config for the new pool */
5075         if (newspa->spa_root_vdev != NULL) {
5076                 VERIFY(nvlist_alloc(&newspa->spa_config_splitting,
5077                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
5078                 VERIFY(nvlist_add_uint64(newspa->spa_config_splitting,
5079                     ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa)) == 0);
5080                 spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
5081                     B_TRUE));
5082         }
5083 
5084         /* set the props */
5085         if (props != NULL) {
5086                 spa_configfile_set(newspa, props, B_FALSE);
5087                 error = spa_prop_set(newspa, props);
5088                 if (error)
5089                         goto out;
5090         }
5091 
5092         /* flush everything */
5093         txg = spa_vdev_config_enter(newspa);
5094         vdev_config_dirty(newspa->spa_root_vdev);
5095         (void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
5096 
5097         if (zio_injection_enabled)
5098                 zio_handle_panic_injection(spa, FTAG, 2);
5099 
5100         spa_async_resume(newspa);
5101 
5102         /* finally, update the original pool's config */
5103         txg = spa_vdev_config_enter(spa);
5104         tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
5105         error = dmu_tx_assign(tx, TXG_WAIT);
5106         if (error != 0)
5107                 dmu_tx_abort(tx);
5108         for (c = 0; c < children; c++) {
5109                 if (vml[c] != NULL) {
5110                         vdev_split(vml[c]);
5111                         if (error == 0)
5112                                 spa_history_log_internal(spa, "detach", tx,
5113                                     "vdev=%s", vml[c]->vdev_path);
5114                         vdev_free(vml[c]);
5115                 }
5116         }
5117         vdev_config_dirty(spa->spa_root_vdev);
5118         spa->spa_config_splitting = NULL;
5119         nvlist_free(nvl);
5120         if (error == 0)
5121                 dmu_tx_commit(tx);
5122         (void) spa_vdev_exit(spa, NULL, txg, 0);
5123 
5124         if (zio_injection_enabled)
5125                 zio_handle_panic_injection(spa, FTAG, 3);
5126 
5127         /* split is complete; log a history record */
5128         spa_history_log_internal(newspa, "split", NULL,
5129             "from pool %s", spa_name(spa));
5130 
5131         kmem_free(vml, children * sizeof (vdev_t *));
5132 
5133         /* if we're not going to mount the filesystems in userland, export */
5134         if (exp)
5135                 error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
5136                     B_FALSE, B_FALSE);
5137 
5138         return (error);
5139 
5140 out:
5141         spa_unload(newspa);
5142         spa_deactivate(newspa);
5143         spa_remove(newspa);
5144 
5145         txg = spa_vdev_config_enter(spa);
5146 
5147         /* re-online all offlined disks */
5148         for (c = 0; c < children; c++) {
5149                 if (vml[c] != NULL)
5150                         vml[c]->vdev_offline = B_FALSE;
5151         }
5152         vdev_reopen(spa->spa_root_vdev);
5153 
5154         nvlist_free(spa->spa_config_splitting);
5155         spa->spa_config_splitting = NULL;
5156         (void) spa_vdev_exit(spa, NULL, txg, error);
5157 
5158         kmem_free(vml, children * sizeof (vdev_t *));
5159         return (error);
5160 }
5161 
5162 static nvlist_t *
5163 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
5164 {
5165         for (int i = 0; i < count; i++) {
5166                 uint64_t guid;
5167 
5168                 VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
5169                     &guid) == 0);
5170 
5171                 if (guid == target_guid)
5172                         return (nvpp[i]);
5173         }
5174 
5175         return (NULL);
5176 }
5177 
5178 static void
5179 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
5180         nvlist_t *dev_to_remove)
5181 {
5182         nvlist_t **newdev = NULL;
5183 
5184         if (count > 1)
5185                 newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
5186 
5187         for (int i = 0, j = 0; i < count; i++) {
5188                 if (dev[i] == dev_to_remove)
5189                         continue;
5190                 VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
5191         }
5192 
5193         VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
5194         VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
5195 
5196         for (int i = 0; i < count - 1; i++)
5197                 nvlist_free(newdev[i]);
5198 
5199         if (count > 1)
5200                 kmem_free(newdev, (count - 1) * sizeof (void *));
5201 }
5202 
5203 /*
5204  * Evacuate the device.
5205  */
5206 static int
5207 spa_vdev_remove_evacuate(spa_t *spa, vdev_t *vd)
5208 {
5209         uint64_t txg;
5210         int error = 0;
5211 
5212         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5213         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5214         ASSERT(vd == vd->vdev_top);
5215 
5216         /*
5217          * Evacuate the device.  We don't hold the config lock as writer
5218          * since we need to do I/O but we do keep the
5219          * spa_namespace_lock held.  Once this completes the device
5220          * should no longer have any blocks allocated on it.
5221          */
5222         if (vd->vdev_islog) {
5223                 if (vd->vdev_stat.vs_alloc != 0)
5224                         error = spa_offline_log(spa);
5225         } else {
5226                 error = SET_ERROR(ENOTSUP);
5227         }
5228 
5229         if (error)
5230                 return (error);
5231 
5232         /*
5233          * The evacuation succeeded.  Remove any remaining MOS metadata
5234          * associated with this vdev, and wait for these changes to sync.
5235          */
5236         ASSERT0(vd->vdev_stat.vs_alloc);
5237         txg = spa_vdev_config_enter(spa);
5238         vd->vdev_removing = B_TRUE;
5239         vdev_dirty_leaves(vd, VDD_DTL, txg);
5240         vdev_config_dirty(vd);
5241         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
5242 
5243         return (0);
5244 }
5245 
5246 /*
5247  * Complete the removal by cleaning up the namespace.
5248  */
5249 static void
5250 spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
5251 {
5252         vdev_t *rvd = spa->spa_root_vdev;
5253         uint64_t id = vd->vdev_id;
5254         boolean_t last_vdev = (id == (rvd->vdev_children - 1));
5255 
5256         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5257         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
5258         ASSERT(vd == vd->vdev_top);
5259 
5260         /*
5261          * Only remove any devices which are empty.
5262          */
5263         if (vd->vdev_stat.vs_alloc != 0)
5264                 return;
5265 
5266         (void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
5267 
5268         if (list_link_active(&vd->vdev_state_dirty_node))
5269                 vdev_state_clean(vd);
5270         if (list_link_active(&vd->vdev_config_dirty_node))
5271                 vdev_config_clean(vd);
5272 
5273         vdev_free(vd);
5274 
5275         if (last_vdev) {
5276                 vdev_compact_children(rvd);
5277         } else {
5278                 vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops);
5279                 vdev_add_child(rvd, vd);
5280         }
5281         vdev_config_dirty(rvd);
5282 
5283         /*
5284          * Reassess the health of our root vdev.
5285          */
5286         vdev_reopen(rvd);
5287 }
5288 
5289 /*
5290  * Remove a device from the pool -
5291  *
5292  * Removing a device from the vdev namespace requires several steps
5293  * and can take a significant amount of time.  As a result we use
5294  * the spa_vdev_config_[enter/exit] functions which allow us to
5295  * grab and release the spa_config_lock while still holding the namespace
5296  * lock.  During each step the configuration is synced out.
5297  *
5298  * Currently, this supports removing only hot spares, slogs, and level 2 ARC
5299  * devices.
5300  */
5301 int
5302 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
5303 {
5304         vdev_t *vd;
5305         metaslab_group_t *mg;
5306         nvlist_t **spares, **l2cache, *nv;
5307         uint64_t txg = 0;
5308         uint_t nspares, nl2cache;
5309         int error = 0;
5310         boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
5311 
5312         ASSERT(spa_writeable(spa));
5313 
5314         if (!locked)
5315                 txg = spa_vdev_enter(spa);
5316 
5317         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
5318 
5319         if (spa->spa_spares.sav_vdevs != NULL &&
5320             nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
5321             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
5322             (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
5323                 /*
5324                  * Only remove the hot spare if it's not currently in use
5325                  * in this pool.
5326                  */
5327                 if (vd == NULL || unspare) {
5328                         spa_vdev_remove_aux(spa->spa_spares.sav_config,
5329                             ZPOOL_CONFIG_SPARES, spares, nspares, nv);
5330                         spa_load_spares(spa);
5331                         spa->spa_spares.sav_sync = B_TRUE;
5332                 } else {
5333                         error = SET_ERROR(EBUSY);
5334                 }
5335         } else if (spa->spa_l2cache.sav_vdevs != NULL &&
5336             nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
5337             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
5338             (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
5339                 /*
5340                  * Cache devices can always be removed.
5341                  */
5342                 spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
5343                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
5344                 spa_load_l2cache(spa);
5345                 spa->spa_l2cache.sav_sync = B_TRUE;
5346         } else if (vd != NULL && vd->vdev_islog) {
5347                 ASSERT(!locked);
5348                 ASSERT(vd == vd->vdev_top);
5349 
5350                 mg = vd->vdev_mg;
5351 
5352                 /*
5353                  * Stop allocating from this vdev.
5354                  */
5355                 metaslab_group_passivate(mg);
5356 
5357                 /*
5358                  * Wait for the youngest allocations and frees to sync,
5359                  * and then wait for the deferral of those frees to finish.
5360                  */
5361                 spa_vdev_config_exit(spa, NULL,
5362                     txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
5363 
5364                 /*
5365                  * Attempt to evacuate the vdev.
5366                  */
5367                 error = spa_vdev_remove_evacuate(spa, vd);
5368 
5369                 txg = spa_vdev_config_enter(spa);
5370 
5371                 /*
5372                  * If we couldn't evacuate the vdev, unwind.
5373                  */
5374                 if (error) {
5375                         metaslab_group_activate(mg);
5376                         return (spa_vdev_exit(spa, NULL, txg, error));
5377                 }
5378 
5379                 /*
5380                  * Clean up the vdev namespace.
5381                  */
5382                 spa_vdev_remove_from_namespace(spa, vd);
5383 
5384         } else if (vd != NULL) {
5385                 /*
5386                  * Normal vdevs cannot be removed (yet).
5387                  */
5388                 error = SET_ERROR(ENOTSUP);
5389         } else {
5390                 /*
5391                  * There is no vdev of any kind with the specified guid.
5392                  */
5393                 error = SET_ERROR(ENOENT);
5394         }
5395 
5396         if (!locked)
5397                 return (spa_vdev_exit(spa, NULL, txg, error));
5398 
5399         return (error);
5400 }
5401 
5402 /*
5403  * Find any device that's done replacing, or a vdev marked 'unspare' that's
5404  * currently spared, so we can detach it.
5405  */
5406 static vdev_t *
5407 spa_vdev_resilver_done_hunt(vdev_t *vd)
5408 {
5409         vdev_t *newvd, *oldvd;
5410 
5411         for (int c = 0; c < vd->vdev_children; c++) {
5412                 oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
5413                 if (oldvd != NULL)
5414                         return (oldvd);
5415         }
5416 
5417         /*
5418          * Check for a completed replacement.  We always consider the first
5419          * vdev in the list to be the oldest vdev, and the last one to be
5420          * the newest (see spa_vdev_attach() for how that works).  In
5421          * the case where the newest vdev is faulted, we will not automatically
5422          * remove it after a resilver completes.  This is OK as it will require
5423          * user intervention to determine which disk the admin wishes to keep.
5424          */
5425         if (vd->vdev_ops == &vdev_replacing_ops) {
5426                 ASSERT(vd->vdev_children > 1);
5427 
5428                 newvd = vd->vdev_child[vd->vdev_children - 1];
5429                 oldvd = vd->vdev_child[0];
5430 
5431                 if (vdev_dtl_empty(newvd, DTL_MISSING) &&
5432                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5433                     !vdev_dtl_required(oldvd))
5434                         return (oldvd);
5435         }
5436 
5437         /*
5438          * Check for a completed resilver with the 'unspare' flag set.
5439          */
5440         if (vd->vdev_ops == &vdev_spare_ops) {
5441                 vdev_t *first = vd->vdev_child[0];
5442                 vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
5443 
5444                 if (last->vdev_unspare) {
5445                         oldvd = first;
5446                         newvd = last;
5447                 } else if (first->vdev_unspare) {
5448                         oldvd = last;
5449                         newvd = first;
5450                 } else {
5451                         oldvd = NULL;
5452                 }
5453 
5454                 if (oldvd != NULL &&
5455                     vdev_dtl_empty(newvd, DTL_MISSING) &&
5456                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5457                     !vdev_dtl_required(oldvd))
5458                         return (oldvd);
5459 
5460                 /*
5461                  * If there are more than two spares attached to a disk,
5462                  * and those spares are not required, then we want to
5463                  * attempt to free them up now so that they can be used
5464                  * by other pools.  Once we're back down to a single
5465                  * disk+spare, we stop removing them.
5466                  */
5467                 if (vd->vdev_children > 2) {
5468                         newvd = vd->vdev_child[1];
5469 
5470                         if (newvd->vdev_isspare && last->vdev_isspare &&
5471                             vdev_dtl_empty(last, DTL_MISSING) &&
5472                             vdev_dtl_empty(last, DTL_OUTAGE) &&
5473                             !vdev_dtl_required(newvd))
5474                                 return (newvd);
5475                 }
5476         }
5477 
5478         return (NULL);
5479 }
5480 
5481 static void
5482 spa_vdev_resilver_done(spa_t *spa)
5483 {
5484         vdev_t *vd, *pvd, *ppvd;
5485         uint64_t guid, sguid, pguid, ppguid;
5486 
5487         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5488 
5489         while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
5490                 pvd = vd->vdev_parent;
5491                 ppvd = pvd->vdev_parent;
5492                 guid = vd->vdev_guid;
5493                 pguid = pvd->vdev_guid;
5494                 ppguid = ppvd->vdev_guid;
5495                 sguid = 0;
5496                 /*
5497                  * If we have just finished replacing a hot spared device, then
5498                  * we need to detach the parent's first child (the original hot
5499                  * spare) as well.
5500                  */
5501                 if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
5502                     ppvd->vdev_children == 2) {
5503                         ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
5504                         sguid = ppvd->vdev_child[1]->vdev_guid;
5505                 }
5506                 ASSERT(vd->vdev_resilver_txg == 0 || !vdev_dtl_required(vd));
5507 
5508                 spa_config_exit(spa, SCL_ALL, FTAG);
5509                 if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
5510                         return;
5511                 if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
5512                         return;
5513                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5514         }
5515 
5516         spa_config_exit(spa, SCL_ALL, FTAG);
5517 }
5518 
5519 /*
5520  * Update the stored path or FRU for this vdev.
5521  */
5522 int
5523 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
5524     boolean_t ispath)
5525 {
5526         vdev_t *vd;
5527         boolean_t sync = B_FALSE;
5528 
5529         ASSERT(spa_writeable(spa));
5530 
5531         spa_vdev_state_enter(spa, SCL_ALL);
5532 
5533         if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
5534                 return (spa_vdev_state_exit(spa, NULL, ENOENT));
5535 
5536         if (!vd->vdev_ops->vdev_op_leaf)
5537                 return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
5538 
5539         if (ispath) {
5540                 if (strcmp(value, vd->vdev_path) != 0) {
5541                         spa_strfree(vd->vdev_path);
5542                         vd->vdev_path = spa_strdup(value);
5543                         sync = B_TRUE;
5544                 }
5545         } else {
5546                 if (vd->vdev_fru == NULL) {
5547                         vd->vdev_fru = spa_strdup(value);
5548                         sync = B_TRUE;
5549                 } else if (strcmp(value, vd->vdev_fru) != 0) {
5550                         spa_strfree(vd->vdev_fru);
5551                         vd->vdev_fru = spa_strdup(value);
5552                         sync = B_TRUE;
5553                 }
5554         }
5555 
5556         return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
5557 }
5558 
5559 int
5560 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
5561 {
5562         return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
5563 }
5564 
5565 int
5566 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
5567 {
5568         return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
5569 }
5570 
5571 /*
5572  * ==========================================================================
5573  * SPA Scanning
5574  * ==========================================================================
5575  */
5576 
5577 int
5578 spa_scan_stop(spa_t *spa)
5579 {
5580         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5581         if (dsl_scan_resilvering(spa->spa_dsl_pool))
5582                 return (SET_ERROR(EBUSY));
5583         return (dsl_scan_cancel(spa->spa_dsl_pool));
5584 }
5585 
5586 int
5587 spa_scan(spa_t *spa, pool_scan_func_t func)
5588 {
5589         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5590 
5591         if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
5592                 return (SET_ERROR(ENOTSUP));
5593 
5594         /*
5595          * If a resilver was requested, but there is no DTL on a
5596          * writeable leaf device, we have nothing to do.
5597          */
5598         if (func == POOL_SCAN_RESILVER &&
5599             !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
5600                 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
5601                 return (0);
5602         }
5603 
5604         return (dsl_scan(spa->spa_dsl_pool, func));
5605 }
5606 
5607 /*
5608  * ==========================================================================
5609  * SPA async task processing
5610  * ==========================================================================
5611  */
5612 
5613 static void
5614 spa_async_remove(spa_t *spa, vdev_t *vd)
5615 {
5616         if (vd->vdev_remove_wanted) {
5617                 vd->vdev_remove_wanted = B_FALSE;
5618                 vd->vdev_delayed_close = B_FALSE;
5619                 vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
5620 
5621                 /*
5622                  * We want to clear the stats, but we don't want to do a full
5623                  * vdev_clear() as that will cause us to throw away
5624                  * degraded/faulted state as well as attempt to reopen the
5625                  * device, all of which is a waste.
5626                  */
5627                 vd->vdev_stat.vs_read_errors = 0;
5628                 vd->vdev_stat.vs_write_errors = 0;
5629                 vd->vdev_stat.vs_checksum_errors = 0;
5630 
5631                 vdev_state_dirty(vd->vdev_top);
5632         }
5633 
5634         for (int c = 0; c < vd->vdev_children; c++)
5635                 spa_async_remove(spa, vd->vdev_child[c]);
5636 }
5637 
5638 static void
5639 spa_async_probe(spa_t *spa, vdev_t *vd)
5640 {
5641         if (vd->vdev_probe_wanted) {
5642                 vd->vdev_probe_wanted = B_FALSE;
5643                 vdev_reopen(vd);        /* vdev_open() does the actual probe */
5644         }
5645 
5646         for (int c = 0; c < vd->vdev_children; c++)
5647                 spa_async_probe(spa, vd->vdev_child[c]);
5648 }
5649 
5650 static void
5651 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
5652 {
5653         sysevent_id_t eid;
5654         nvlist_t *attr;
5655         char *physpath;
5656 
5657         if (!spa->spa_autoexpand)
5658                 return;
5659 
5660         for (int c = 0; c < vd->vdev_children; c++) {
5661                 vdev_t *cvd = vd->vdev_child[c];
5662                 spa_async_autoexpand(spa, cvd);
5663         }
5664 
5665         if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
5666                 return;
5667 
5668         physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
5669         (void) snprintf(physpath, MAXPATHLEN, "/devices%s", vd->vdev_physpath);
5670 
5671         VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5672         VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
5673 
5674         (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
5675             ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
5676 
5677         nvlist_free(attr);
5678         kmem_free(physpath, MAXPATHLEN);
5679 }
5680 
5681 static void
5682 spa_async_thread(spa_t *spa)
5683 {
5684         int tasks;
5685 
5686         ASSERT(spa->spa_sync_on);
5687 
5688         mutex_enter(&spa->spa_async_lock);
5689         tasks = spa->spa_async_tasks;
5690         spa->spa_async_tasks = 0;
5691         mutex_exit(&spa->spa_async_lock);
5692 
5693         /*
5694          * See if the config needs to be updated.
5695          */
5696         if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
5697                 uint64_t old_space, new_space;
5698 
5699                 mutex_enter(&spa_namespace_lock);
5700                 old_space = metaslab_class_get_space(spa_normal_class(spa));
5701                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
5702                 new_space = metaslab_class_get_space(spa_normal_class(spa));
5703                 mutex_exit(&spa_namespace_lock);
5704 
5705                 /*
5706                  * If the pool grew as a result of the config update,
5707                  * then log an internal history event.
5708                  */
5709                 if (new_space != old_space) {
5710                         spa_history_log_internal(spa, "vdev online", NULL,
5711                             "pool '%s' size: %llu(+%llu)",
5712                             spa_name(spa), new_space, new_space - old_space);
5713                 }
5714         }
5715 
5716         /*
5717          * See if any devices need to be marked REMOVED.
5718          */
5719         if (tasks & SPA_ASYNC_REMOVE) {
5720                 spa_vdev_state_enter(spa, SCL_NONE);
5721                 spa_async_remove(spa, spa->spa_root_vdev);
5722                 for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
5723                         spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
5724                 for (int i = 0; i < spa->spa_spares.sav_count; i++)
5725                         spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
5726                 (void) spa_vdev_state_exit(spa, NULL, 0);
5727         }
5728 
5729         if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
5730                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5731                 spa_async_autoexpand(spa, spa->spa_root_vdev);
5732                 spa_config_exit(spa, SCL_CONFIG, FTAG);
5733         }
5734 
5735         /*
5736          * See if any devices need to be probed.
5737          */
5738         if (tasks & SPA_ASYNC_PROBE) {
5739                 spa_vdev_state_enter(spa, SCL_NONE);
5740                 spa_async_probe(spa, spa->spa_root_vdev);
5741                 (void) spa_vdev_state_exit(spa, NULL, 0);
5742         }
5743 
5744         /*
5745          * If any devices are done replacing, detach them.
5746          */
5747         if (tasks & SPA_ASYNC_RESILVER_DONE)
5748                 spa_vdev_resilver_done(spa);
5749 
5750         /*
5751          * Kick off a resilver.
5752          */
5753         if (tasks & SPA_ASYNC_RESILVER)
5754                 dsl_resilver_restart(spa->spa_dsl_pool, 0);
5755 
5756         /*
5757          * Let the world know that we're done.
5758          */
5759         mutex_enter(&spa->spa_async_lock);
5760         spa->spa_async_thread = NULL;
5761         cv_broadcast(&spa->spa_async_cv);
5762         mutex_exit(&spa->spa_async_lock);
5763         thread_exit();
5764 }
5765 
5766 void
5767 spa_async_suspend(spa_t *spa)
5768 {
5769         mutex_enter(&spa->spa_async_lock);
5770         spa->spa_async_suspended++;
5771         while (spa->spa_async_thread != NULL)
5772                 cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
5773         mutex_exit(&spa->spa_async_lock);
5774 }
5775 
5776 void
5777 spa_async_resume(spa_t *spa)
5778 {
5779         mutex_enter(&spa->spa_async_lock);
5780         ASSERT(spa->spa_async_suspended != 0);
5781         spa->spa_async_suspended--;
5782         mutex_exit(&spa->spa_async_lock);
5783 }
5784 
5785 static boolean_t
5786 spa_async_tasks_pending(spa_t *spa)
5787 {
5788         uint_t non_config_tasks;
5789         uint_t config_task;
5790         boolean_t config_task_suspended;
5791 
5792         non_config_tasks = spa->spa_async_tasks & ~SPA_ASYNC_CONFIG_UPDATE;
5793         config_task = spa->spa_async_tasks & SPA_ASYNC_CONFIG_UPDATE;
5794         if (spa->spa_ccw_fail_time == 0) {
5795                 config_task_suspended = B_FALSE;
5796         } else {
5797                 config_task_suspended =
5798                     (gethrtime() - spa->spa_ccw_fail_time) <
5799                     (zfs_ccw_retry_interval * NANOSEC);
5800         }
5801 
5802         return (non_config_tasks || (config_task && !config_task_suspended));
5803 }
5804 
5805 static void
5806 spa_async_dispatch(spa_t *spa)
5807 {
5808         mutex_enter(&spa->spa_async_lock);
5809         if (spa_async_tasks_pending(spa) &&
5810             !spa->spa_async_suspended &&
5811             spa->spa_async_thread == NULL &&
5812             rootdir != NULL)
5813                 spa->spa_async_thread = thread_create(NULL, 0,
5814                     spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
5815         mutex_exit(&spa->spa_async_lock);
5816 }
5817 
5818 void
5819 spa_async_request(spa_t *spa, int task)
5820 {
5821         zfs_dbgmsg("spa=%s async request task=%u", spa->spa_name, task);
5822         mutex_enter(&spa->spa_async_lock);
5823         spa->spa_async_tasks |= task;
5824         mutex_exit(&spa->spa_async_lock);
5825 }
5826 
5827 /*
5828  * ==========================================================================
5829  * SPA syncing routines
5830  * ==========================================================================
5831  */
5832 
5833 static int
5834 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5835 {
5836         bpobj_t *bpo = arg;
5837         bpobj_enqueue(bpo, bp, tx);
5838         return (0);
5839 }
5840 
5841 static int
5842 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5843 {
5844         zio_t *zio = arg;
5845 
5846         zio_nowait(zio_free_sync(zio, zio->io_spa, dmu_tx_get_txg(tx), bp,
5847             zio->io_flags));
5848         return (0);
5849 }
5850 
5851 /*
5852  * Note: this simple function is not inlined to make it easier to dtrace the
5853  * amount of time spent syncing frees.
5854  */
5855 static void
5856 spa_sync_frees(spa_t *spa, bplist_t *bpl, dmu_tx_t *tx)
5857 {
5858         zio_t *zio = zio_root(spa, NULL, NULL, 0);
5859         bplist_iterate(bpl, spa_free_sync_cb, zio, tx);
5860         VERIFY(zio_wait(zio) == 0);
5861 }
5862 
5863 /*
5864  * Note: this simple function is not inlined to make it easier to dtrace the
5865  * amount of time spent syncing deferred frees.
5866  */
5867 static void
5868 spa_sync_deferred_frees(spa_t *spa, dmu_tx_t *tx)
5869 {
5870         zio_t *zio = zio_root(spa, NULL, NULL, 0);
5871         VERIFY3U(bpobj_iterate(&spa->spa_deferred_bpobj,
5872             spa_free_sync_cb, zio, tx), ==, 0);
5873         VERIFY0(zio_wait(zio));
5874 }
5875 
5876 
5877 static void
5878 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
5879 {
5880         char *packed = NULL;
5881         size_t bufsize;
5882         size_t nvsize = 0;
5883         dmu_buf_t *db;
5884 
5885         VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
5886 
5887         /*
5888          * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
5889          * information.  This avoids the dmu_buf_will_dirty() path and
5890          * saves us a pre-read to get data we don't actually care about.
5891          */
5892         bufsize = P2ROUNDUP((uint64_t)nvsize, SPA_CONFIG_BLOCKSIZE);
5893         packed = kmem_alloc(bufsize, KM_SLEEP);
5894 
5895         VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
5896             KM_SLEEP) == 0);
5897         bzero(packed + nvsize, bufsize - nvsize);
5898 
5899         dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
5900 
5901         kmem_free(packed, bufsize);
5902 
5903         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
5904         dmu_buf_will_dirty(db, tx);
5905         *(uint64_t *)db->db_data = nvsize;
5906         dmu_buf_rele(db, FTAG);
5907 }
5908 
5909 static void
5910 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
5911     const char *config, const char *entry)
5912 {
5913         nvlist_t *nvroot;
5914         nvlist_t **list;
5915         int i;
5916 
5917         if (!sav->sav_sync)
5918                 return;
5919 
5920         /*
5921          * Update the MOS nvlist describing the list of available devices.
5922          * spa_validate_aux() will have already made sure this nvlist is
5923          * valid and the vdevs are labeled appropriately.
5924          */
5925         if (sav->sav_object == 0) {
5926                 sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
5927                     DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
5928                     sizeof (uint64_t), tx);
5929                 VERIFY(zap_update(spa->spa_meta_objset,
5930                     DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
5931                     &sav->sav_object, tx) == 0);
5932         }
5933 
5934         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5935         if (sav->sav_count == 0) {
5936                 VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
5937         } else {
5938                 list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
5939                 for (i = 0; i < sav->sav_count; i++)
5940                         list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
5941                             B_FALSE, VDEV_CONFIG_L2CACHE);
5942                 VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
5943                     sav->sav_count) == 0);
5944                 for (i = 0; i < sav->sav_count; i++)
5945                         nvlist_free(list[i]);
5946                 kmem_free(list, sav->sav_count * sizeof (void *));
5947         }
5948 
5949         spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
5950         nvlist_free(nvroot);
5951 
5952         sav->sav_sync = B_FALSE;
5953 }
5954 
5955 static void
5956 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
5957 {
5958         nvlist_t *config;
5959 
5960         if (list_is_empty(&spa->spa_config_dirty_list))
5961                 return;
5962 
5963         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5964 
5965         config = spa_config_generate(spa, spa->spa_root_vdev,
5966             dmu_tx_get_txg(tx), B_FALSE);
5967 
5968         /*
5969          * If we're upgrading the spa version then make sure that
5970          * the config object gets updated with the correct version.
5971          */
5972         if (spa->spa_ubsync.ub_version < spa->spa_uberblock.ub_version)
5973                 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
5974                     spa->spa_uberblock.ub_version);
5975 
5976         spa_config_exit(spa, SCL_STATE, FTAG);
5977 
5978         if (spa->spa_config_syncing)
5979                 nvlist_free(spa->spa_config_syncing);
5980         spa->spa_config_syncing = config;
5981 
5982         spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
5983 }
5984 
5985 static void
5986 spa_sync_version(void *arg, dmu_tx_t *tx)
5987 {
5988         uint64_t *versionp = arg;
5989         uint64_t version = *versionp;
5990         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5991 
5992         /*
5993          * Setting the version is special cased when first creating the pool.
5994          */
5995         ASSERT(tx->tx_txg != TXG_INITIAL);
5996 
5997         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
5998         ASSERT(version >= spa_version(spa));
5999 
6000         spa->spa_uberblock.ub_version = version;
6001         vdev_config_dirty(spa->spa_root_vdev);
6002         spa_history_log_internal(spa, "set", tx, "version=%lld", version);
6003 }
6004 
6005 /*
6006  * Set zpool properties.
6007  */
6008 static void
6009 spa_sync_props(void *arg, dmu_tx_t *tx)
6010 {
6011         nvlist_t *nvp = arg;
6012         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
6013         objset_t *mos = spa->spa_meta_objset;
6014         nvpair_t *elem = NULL;
6015 
6016         mutex_enter(&spa->spa_props_lock);
6017 
6018         while ((elem = nvlist_next_nvpair(nvp, elem))) {
6019                 uint64_t intval;
6020                 char *strval, *fname;
6021                 zpool_prop_t prop;
6022                 const char *propname;
6023                 zprop_type_t proptype;
6024                 spa_feature_t fid;
6025 
6026                 switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
6027                 case ZPROP_INVAL:
6028                         /*
6029                          * We checked this earlier in spa_prop_validate().
6030                          */
6031                         ASSERT(zpool_prop_feature(nvpair_name(elem)));
6032 
6033                         fname = strchr(nvpair_name(elem), '@') + 1;
6034                         VERIFY0(zfeature_lookup_name(fname, &fid));
6035 
6036                         spa_feature_enable(spa, fid, tx);
6037                         spa_history_log_internal(spa, "set", tx,
6038                             "%s=enabled", nvpair_name(elem));
6039                         break;
6040 
6041                 case ZPOOL_PROP_VERSION:
6042                         intval = fnvpair_value_uint64(elem);
6043                         /*
6044                          * The version is synced seperatly before other
6045                          * properties and should be correct by now.
6046                          */
6047                         ASSERT3U(spa_version(spa), >=, intval);
6048                         break;
6049 
6050                 case ZPOOL_PROP_ALTROOT:
6051                         /*
6052                          * 'altroot' is a non-persistent property. It should
6053                          * have been set temporarily at creation or import time.
6054                          */
6055                         ASSERT(spa->spa_root != NULL);
6056                         break;
6057 
6058                 case ZPOOL_PROP_READONLY:
6059                 case ZPOOL_PROP_CACHEFILE:
6060                         /*
6061                          * 'readonly' and 'cachefile' are also non-persisitent
6062                          * properties.
6063                          */
6064                         break;
6065                 case ZPOOL_PROP_COMMENT:
6066                         strval = fnvpair_value_string(elem);
6067                         if (spa->spa_comment != NULL)
6068                                 spa_strfree(spa->spa_comment);
6069                         spa->spa_comment = spa_strdup(strval);
6070                         /*
6071                          * We need to dirty the configuration on all the vdevs
6072                          * so that their labels get updated.  It's unnecessary
6073                          * to do this for pool creation since the vdev's
6074                          * configuratoin has already been dirtied.
6075                          */
6076                         if (tx->tx_txg != TXG_INITIAL)
6077                                 vdev_config_dirty(spa->spa_root_vdev);
6078                         spa_history_log_internal(spa, "set", tx,
6079                             "%s=%s", nvpair_name(elem), strval);
6080                         break;
6081                 default:
6082                         /*
6083                          * Set pool property values in the poolprops mos object.
6084                          */
6085                         if (spa->spa_pool_props_object == 0) {
6086                                 spa->spa_pool_props_object =
6087                                     zap_create_link(mos, DMU_OT_POOL_PROPS,
6088                                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
6089                                     tx);
6090                         }
6091 
6092                         /* normalize the property name */
6093                         propname = zpool_prop_to_name(prop);
6094                         proptype = zpool_prop_get_type(prop);
6095 
6096                         if (nvpair_type(elem) == DATA_TYPE_STRING) {
6097                                 ASSERT(proptype == PROP_TYPE_STRING);
6098                                 strval = fnvpair_value_string(elem);
6099                                 VERIFY0(zap_update(mos,
6100                                     spa->spa_pool_props_object, propname,
6101                                     1, strlen(strval) + 1, strval, tx));
6102                                 spa_history_log_internal(spa, "set", tx,
6103                                     "%s=%s", nvpair_name(elem), strval);
6104                         } else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
6105                                 intval = fnvpair_value_uint64(elem);
6106 
6107                                 if (proptype == PROP_TYPE_INDEX) {
6108                                         const char *unused;
6109                                         VERIFY0(zpool_prop_index_to_string(
6110                                             prop, intval, &unused));
6111                                 }
6112                                 VERIFY0(zap_update(mos,
6113                                     spa->spa_pool_props_object, propname,
6114                                     8, 1, &intval, tx));
6115                                 spa_history_log_internal(spa, "set", tx,
6116                                     "%s=%lld", nvpair_name(elem), intval);
6117                         } else {
6118                                 ASSERT(0); /* not allowed */
6119                         }
6120 
6121                         switch (prop) {
6122                         case ZPOOL_PROP_DELEGATION:
6123                                 spa->spa_delegation = intval;
6124                                 break;
6125                         case ZPOOL_PROP_BOOTFS:
6126                                 spa->spa_bootfs = intval;
6127                                 break;
6128                         case ZPOOL_PROP_FAILUREMODE:
6129                                 spa->spa_failmode = intval;
6130                                 break;
6131                         case ZPOOL_PROP_AUTOEXPAND:
6132                                 spa->spa_autoexpand = intval;
6133                                 if (tx->tx_txg != TXG_INITIAL)
6134                                         spa_async_request(spa,
6135                                             SPA_ASYNC_AUTOEXPAND);
6136                                 break;
6137                         case ZPOOL_PROP_DEDUPDITTO:
6138                                 spa->spa_dedup_ditto = intval;
6139                                 break;
6140                         default:
6141                                 break;
6142                         }
6143                 }
6144 
6145         }
6146 
6147         mutex_exit(&spa->spa_props_lock);
6148 }
6149 
6150 /*
6151  * Perform one-time upgrade on-disk changes.  spa_version() does not
6152  * reflect the new version this txg, so there must be no changes this
6153  * txg to anything that the upgrade code depends on after it executes.
6154  * Therefore this must be called after dsl_pool_sync() does the sync
6155  * tasks.
6156  */
6157 static void
6158 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
6159 {
6160         dsl_pool_t *dp = spa->spa_dsl_pool;
6161 
6162         ASSERT(spa->spa_sync_pass == 1);
6163 
6164         rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
6165 
6166         if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
6167             spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
6168                 dsl_pool_create_origin(dp, tx);
6169 
6170                 /* Keeping the origin open increases spa_minref */
6171                 spa->spa_minref += 3;
6172         }
6173 
6174         if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
6175             spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
6176                 dsl_pool_upgrade_clones(dp, tx);
6177         }
6178 
6179         if (spa->spa_ubsync.ub_version < SPA_VERSION_DIR_CLONES &&
6180             spa->spa_uberblock.ub_version >= SPA_VERSION_DIR_CLONES) {
6181                 dsl_pool_upgrade_dir_clones(dp, tx);
6182 
6183                 /* Keeping the freedir open increases spa_minref */
6184                 spa->spa_minref += 3;
6185         }
6186 
6187         if (spa->spa_ubsync.ub_version < SPA_VERSION_FEATURES &&
6188             spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
6189                 spa_feature_create_zap_objects(spa, tx);
6190         }
6191 
6192         /*
6193          * LZ4_COMPRESS feature's behaviour was changed to activate_on_enable
6194          * when possibility to use lz4 compression for metadata was added
6195          * Old pools that have this feature enabled must be upgraded to have
6196          * this feature active
6197          */
6198         if (spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
6199                 boolean_t lz4_en = spa_feature_is_enabled(spa,
6200                     SPA_FEATURE_LZ4_COMPRESS);
6201                 boolean_t lz4_ac = spa_feature_is_active(spa,
6202                     SPA_FEATURE_LZ4_COMPRESS);
6203 
6204                 if (lz4_en && !lz4_ac)
6205                         spa_feature_incr(spa, SPA_FEATURE_LZ4_COMPRESS, tx);
6206         }
6207         rrw_exit(&dp->dp_config_rwlock, FTAG);
6208 }
6209 
6210 /*
6211  * Sync the specified transaction group.  New blocks may be dirtied as
6212  * part of the process, so we iterate until it converges.
6213  */
6214 void
6215 spa_sync(spa_t *spa, uint64_t txg)
6216 {
6217         dsl_pool_t *dp = spa->spa_dsl_pool;
6218         objset_t *mos = spa->spa_meta_objset;
6219         bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
6220         vdev_t *rvd = spa->spa_root_vdev;
6221         vdev_t *vd;
6222         dmu_tx_t *tx;
6223         int error;
6224 
6225         VERIFY(spa_writeable(spa));
6226 
6227         /*
6228          * Lock out configuration changes.
6229          */
6230         spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
6231 
6232         spa->spa_syncing_txg = txg;
6233         spa->spa_sync_pass = 0;
6234 
6235         /*
6236          * If there are any pending vdev state changes, convert them
6237          * into config changes that go out with this transaction group.
6238          */
6239         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6240         while (list_head(&spa->spa_state_dirty_list) != NULL) {
6241                 /*
6242                  * We need the write lock here because, for aux vdevs,
6243                  * calling vdev_config_dirty() modifies sav_config.
6244                  * This is ugly and will become unnecessary when we
6245                  * eliminate the aux vdev wart by integrating all vdevs
6246                  * into the root vdev tree.
6247                  */
6248                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6249                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
6250                 while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
6251                         vdev_state_clean(vd);
6252                         vdev_config_dirty(vd);
6253                 }
6254                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6255                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
6256         }
6257         spa_config_exit(spa, SCL_STATE, FTAG);
6258 
6259         tx = dmu_tx_create_assigned(dp, txg);
6260 
6261         spa->spa_sync_starttime = gethrtime();
6262         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid,
6263             spa->spa_sync_starttime + spa->spa_deadman_synctime));
6264 
6265         /*
6266          * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
6267          * set spa_deflate if we have no raid-z vdevs.
6268          */
6269         if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
6270             spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
6271                 int i;
6272 
6273                 for (i = 0; i < rvd->vdev_children; i++) {
6274                         vd = rvd->vdev_child[i];
6275                         if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
6276                                 break;
6277                 }
6278                 if (i == rvd->vdev_children) {
6279                         spa->spa_deflate = TRUE;
6280                         VERIFY(0 == zap_add(spa->spa_meta_objset,
6281                             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
6282                             sizeof (uint64_t), 1, &spa->spa_deflate, tx));
6283                 }
6284         }
6285 
6286         /*
6287          * Iterate to convergence.
6288          */
6289         do {
6290                 int pass = ++spa->spa_sync_pass;
6291 
6292                 spa_sync_config_object(spa, tx);
6293                 spa_sync_aux_dev(spa, &spa->spa_spares, tx,
6294                     ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
6295                 spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
6296                     ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
6297                 spa_errlog_sync(spa, txg);
6298                 dsl_pool_sync(dp, txg);
6299 
6300                 if (pass < zfs_sync_pass_deferred_free) {
6301                         spa_sync_frees(spa, free_bpl, tx);
6302                 } else {
6303                         /*
6304                          * We can not defer frees in pass 1, because
6305                          * we sync the deferred frees later in pass 1.
6306                          */
6307                         ASSERT3U(pass, >, 1);
6308                         bplist_iterate(free_bpl, bpobj_enqueue_cb,
6309                             &spa->spa_deferred_bpobj, tx);
6310                 }
6311 
6312                 ddt_sync(spa, txg);
6313                 dsl_scan_sync(dp, tx);
6314 
6315                 while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
6316                         vdev_sync(vd, txg);
6317 
6318                 if (pass == 1) {
6319                         spa_sync_upgrades(spa, tx);
6320                         ASSERT3U(txg, >=,
6321                             spa->spa_uberblock.ub_rootbp.blk_birth);
6322                         /*
6323                          * Note: We need to check if the MOS is dirty
6324                          * because we could have marked the MOS dirty
6325                          * without updating the uberblock (e.g. if we
6326                          * have sync tasks but no dirty user data).  We
6327                          * need to check the uberblock's rootbp because
6328                          * it is updated if we have synced out dirty
6329                          * data (though in this case the MOS will most
6330                          * likely also be dirty due to second order
6331                          * effects, we don't want to rely on that here).
6332                          */
6333                         if (spa->spa_uberblock.ub_rootbp.blk_birth < txg &&
6334                             !dmu_objset_is_dirty(mos, txg)) {
6335                                 /*
6336                                  * Nothing changed on the first pass,
6337                                  * therefore this TXG is a no-op.  Avoid
6338                                  * syncing deferred frees, so that we
6339                                  * can keep this TXG as a no-op.
6340                                  */
6341                                 ASSERT(txg_list_empty(&dp->dp_dirty_datasets,
6342                                     txg));
6343                                 ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
6344                                 ASSERT(txg_list_empty(&dp->dp_sync_tasks, txg));
6345                                 break;
6346                         }
6347                         spa_sync_deferred_frees(spa, tx);
6348                 }
6349 
6350         } while (dmu_objset_is_dirty(mos, txg));
6351 
6352         /*
6353          * Rewrite the vdev configuration (which includes the uberblock)
6354          * to commit the transaction group.
6355          *
6356          * If there are no dirty vdevs, we sync the uberblock to a few
6357          * random top-level vdevs that are known to be visible in the
6358          * config cache (see spa_vdev_add() for a complete description).
6359          * If there *are* dirty vdevs, sync the uberblock to all vdevs.
6360          */
6361         for (;;) {
6362                 /*
6363                  * We hold SCL_STATE to prevent vdev open/close/etc.
6364                  * while we're attempting to write the vdev labels.
6365                  */
6366                 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6367 
6368                 if (list_is_empty(&spa->spa_config_dirty_list)) {
6369                         vdev_t *svd[SPA_DVAS_PER_BP];
6370                         int svdcount = 0;
6371                         int children = rvd->vdev_children;
6372                         int c0 = spa_get_random(children);
6373 
6374                         for (int c = 0; c < children; c++) {
6375                                 vd = rvd->vdev_child[(c0 + c) % children];
6376                                 if (vd->vdev_ms_array == 0 || vd->vdev_islog)
6377                                         continue;
6378                                 svd[svdcount++] = vd;
6379                                 if (svdcount == SPA_DVAS_PER_BP)
6380                                         break;
6381                         }
6382                         error = vdev_config_sync(svd, svdcount, txg, B_FALSE);
6383                         if (error != 0)
6384                                 error = vdev_config_sync(svd, svdcount, txg,
6385                                     B_TRUE);
6386                 } else {
6387                         error = vdev_config_sync(rvd->vdev_child,
6388                             rvd->vdev_children, txg, B_FALSE);
6389                         if (error != 0)
6390                                 error = vdev_config_sync(rvd->vdev_child,
6391                                     rvd->vdev_children, txg, B_TRUE);
6392                 }
6393 
6394                 if (error == 0)
6395                         spa->spa_last_synced_guid = rvd->vdev_guid;
6396 
6397                 spa_config_exit(spa, SCL_STATE, FTAG);
6398 
6399                 if (error == 0)
6400                         break;
6401                 zio_suspend(spa, NULL);
6402                 zio_resume_wait(spa);
6403         }
6404         dmu_tx_commit(tx);
6405 
6406         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
6407 
6408         /*
6409          * Clear the dirty config list.
6410          */
6411         while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
6412                 vdev_config_clean(vd);
6413 
6414         /*
6415          * Now that the new config has synced transactionally,
6416          * let it become visible to the config cache.
6417          */
6418         if (spa->spa_config_syncing != NULL) {
6419                 spa_config_set(spa, spa->spa_config_syncing);
6420                 spa->spa_config_txg = txg;
6421                 spa->spa_config_syncing = NULL;
6422         }
6423 
6424         spa->spa_ubsync = spa->spa_uberblock;
6425 
6426         dsl_pool_sync_done(dp, txg);
6427 
6428         /*
6429          * Update usable space statistics.
6430          */
6431         while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
6432                 vdev_sync_done(vd, txg);
6433 
6434         spa_update_dspace(spa);
6435 
6436         /*
6437          * It had better be the case that we didn't dirty anything
6438          * since vdev_config_sync().
6439          */
6440         ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
6441         ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
6442         ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
6443 
6444         spa->spa_sync_pass = 0;
6445 
6446         spa_config_exit(spa, SCL_CONFIG, FTAG);
6447 
6448         spa_handle_ignored_writes(spa);
6449 
6450         /*
6451          * If any async tasks have been requested, kick them off.
6452          */
6453         spa_async_dispatch(spa);
6454 }
6455 
6456 /*
6457  * Sync all pools.  We don't want to hold the namespace lock across these
6458  * operations, so we take a reference on the spa_t and drop the lock during the
6459  * sync.
6460  */
6461 void
6462 spa_sync_allpools(void)
6463 {
6464         spa_t *spa = NULL;
6465         mutex_enter(&spa_namespace_lock);
6466         while ((spa = spa_next(spa)) != NULL) {
6467                 if (spa_state(spa) != POOL_STATE_ACTIVE ||
6468                     !spa_writeable(spa) || spa_suspended(spa))
6469                         continue;
6470                 spa_open_ref(spa, FTAG);
6471                 mutex_exit(&spa_namespace_lock);
6472                 txg_wait_synced(spa_get_dsl(spa), 0);
6473                 mutex_enter(&spa_namespace_lock);
6474                 spa_close(spa, FTAG);
6475         }
6476         mutex_exit(&spa_namespace_lock);
6477 }
6478 
6479 /*
6480  * ==========================================================================
6481  * Miscellaneous routines
6482  * ==========================================================================
6483  */
6484 
6485 /*
6486  * Remove all pools in the system.
6487  */
6488 void
6489 spa_evict_all(void)
6490 {
6491         spa_t *spa;
6492 
6493         /*
6494          * Remove all cached state.  All pools should be closed now,
6495          * so every spa in the AVL tree should be unreferenced.
6496          */
6497         mutex_enter(&spa_namespace_lock);
6498         while ((spa = spa_next(NULL)) != NULL) {
6499                 /*
6500                  * Stop async tasks.  The async thread may need to detach
6501                  * a device that's been replaced, which requires grabbing
6502                  * spa_namespace_lock, so we must drop it here.
6503                  */
6504                 spa_open_ref(spa, FTAG);
6505                 mutex_exit(&spa_namespace_lock);
6506                 spa_async_suspend(spa);
6507                 mutex_enter(&spa_namespace_lock);
6508                 spa_close(spa, FTAG);
6509 
6510                 if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
6511                         spa_unload(spa);
6512                         spa_deactivate(spa);
6513                 }
6514                 spa_remove(spa);
6515         }
6516         mutex_exit(&spa_namespace_lock);
6517 }
6518 
6519 vdev_t *
6520 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
6521 {
6522         vdev_t *vd;
6523         int i;
6524 
6525         if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
6526                 return (vd);
6527 
6528         if (aux) {
6529                 for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
6530                         vd = spa->spa_l2cache.sav_vdevs[i];
6531                         if (vd->vdev_guid == guid)
6532                                 return (vd);
6533                 }
6534 
6535                 for (i = 0; i < spa->spa_spares.sav_count; i++) {
6536                         vd = spa->spa_spares.sav_vdevs[i];
6537                         if (vd->vdev_guid == guid)
6538                                 return (vd);
6539                 }
6540         }
6541 
6542         return (NULL);
6543 }
6544 
6545 void
6546 spa_upgrade(spa_t *spa, uint64_t version)
6547 {
6548         ASSERT(spa_writeable(spa));
6549 
6550         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6551 
6552         /*
6553          * This should only be called for a non-faulted pool, and since a
6554          * future version would result in an unopenable pool, this shouldn't be
6555          * possible.
6556          */
6557         ASSERT(SPA_VERSION_IS_SUPPORTED(spa->spa_uberblock.ub_version));
6558         ASSERT3U(version, >=, spa->spa_uberblock.ub_version);
6559 
6560         spa->spa_uberblock.ub_version = version;
6561         vdev_config_dirty(spa->spa_root_vdev);
6562 
6563         spa_config_exit(spa, SCL_ALL, FTAG);
6564 
6565         txg_wait_synced(spa_get_dsl(spa), 0);
6566 }
6567 
6568 boolean_t
6569 spa_has_spare(spa_t *spa, uint64_t guid)
6570 {
6571         int i;
6572         uint64_t spareguid;
6573         spa_aux_vdev_t *sav = &spa->spa_spares;
6574 
6575         for (i = 0; i < sav->sav_count; i++)
6576                 if (sav->sav_vdevs[i]->vdev_guid == guid)
6577                         return (B_TRUE);
6578 
6579         for (i = 0; i < sav->sav_npending; i++) {
6580                 if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
6581                     &spareguid) == 0 && spareguid == guid)
6582                         return (B_TRUE);
6583         }
6584 
6585         return (B_FALSE);
6586 }
6587 
6588 /*
6589  * Check if a pool has an active shared spare device.
6590  * Note: reference count of an active spare is 2, as a spare and as a replace
6591  */
6592 static boolean_t
6593 spa_has_active_shared_spare(spa_t *spa)
6594 {
6595         int i, refcnt;
6596         uint64_t pool;
6597         spa_aux_vdev_t *sav = &spa->spa_spares;
6598 
6599         for (i = 0; i < sav->sav_count; i++) {
6600                 if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
6601                     &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
6602                     refcnt > 2)
6603                         return (B_TRUE);
6604         }
6605 
6606         return (B_FALSE);
6607 }
6608 
6609 /*
6610  * Post a sysevent corresponding to the given event.  The 'name' must be one of
6611  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
6612  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
6613  * in the userland libzpool, as we don't want consumers to misinterpret ztest
6614  * or zdb as real changes.
6615  */
6616 void
6617 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
6618 {
6619 #ifdef _KERNEL
6620         sysevent_t              *ev;
6621         sysevent_attr_list_t    *attr = NULL;
6622         sysevent_value_t        value;
6623         sysevent_id_t           eid;
6624 
6625         ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
6626             SE_SLEEP);
6627 
6628         value.value_type = SE_DATA_TYPE_STRING;
6629         value.value.sv_string = spa_name(spa);
6630         if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
6631                 goto done;
6632 
6633         value.value_type = SE_DATA_TYPE_UINT64;
6634         value.value.sv_uint64 = spa_guid(spa);
6635         if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
6636                 goto done;
6637 
6638         if (vd) {
6639                 value.value_type = SE_DATA_TYPE_UINT64;
6640                 value.value.sv_uint64 = vd->vdev_guid;
6641                 if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
6642                     SE_SLEEP) != 0)
6643                         goto done;
6644 
6645                 if (vd->vdev_path) {
6646                         value.value_type = SE_DATA_TYPE_STRING;
6647                         value.value.sv_string = vd->vdev_path;
6648                         if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
6649                             &value, SE_SLEEP) != 0)
6650                                 goto done;
6651                 }
6652         }
6653 
6654         if (sysevent_attach_attributes(ev, attr) != 0)
6655                 goto done;
6656         attr = NULL;
6657 
6658         (void) log_sysevent(ev, SE_SLEEP, &eid);
6659 
6660 done:
6661         if (attr)
6662                 sysevent_free_attr(attr);
6663         sysevent_free(ev);
6664 #endif
6665 }