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) 2015, Nexenta Systems, Inc.  All rights reserved.
  26  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  27  * Copyright 2013 Saso Kiselkov. All rights reserved.
  28  * Copyright (c) 2014 Integros [integros.com]
  29  */
  30 
  31 /*
  32  * SPA: Storage Pool Allocator
  33  *
  34  * This file contains all the routines used when modifying on-disk SPA state.
  35  * This includes opening, importing, destroying, exporting a pool, and syncing a
  36  * pool.
  37  */
  38 
  39 #include <sys/zfs_context.h>
  40 #include <sys/fm/fs/zfs.h>
  41 #include <sys/spa_impl.h>
  42 #include <sys/zio.h>
  43 #include <sys/zio_checksum.h>
  44 #include <sys/dmu.h>
  45 #include <sys/dmu_tx.h>
  46 #include <sys/zap.h>
  47 #include <sys/zil.h>
  48 #include <sys/ddt.h>
  49 #include <sys/vdev_impl.h>
  50 #include <sys/metaslab.h>
  51 #include <sys/metaslab_impl.h>
  52 #include <sys/uberblock_impl.h>
  53 #include <sys/txg.h>
  54 #include <sys/avl.h>
  55 #include <sys/dmu_traverse.h>
  56 #include <sys/dmu_objset.h>
  57 #include <sys/unique.h>
  58 #include <sys/dsl_pool.h>
  59 #include <sys/dsl_dataset.h>
  60 #include <sys/dsl_dir.h>
  61 #include <sys/dsl_prop.h>
  62 #include <sys/dsl_synctask.h>
  63 #include <sys/fs/zfs.h>
  64 #include <sys/arc.h>
  65 #include <sys/callb.h>
  66 #include <sys/systeminfo.h>
  67 #include <sys/spa_boot.h>
  68 #include <sys/zfs_ioctl.h>
  69 #include <sys/dsl_scan.h>
  70 #include <sys/zfeature.h>
  71 #include <sys/dsl_destroy.h>
  72 
  73 #ifdef  _KERNEL
  74 #include <sys/bootprops.h>
  75 #include <sys/callb.h>
  76 #include <sys/cpupart.h>
  77 #include <sys/pool.h>
  78 #include <sys/sysdc.h>
  79 #include <sys/zone.h>
  80 #endif  /* _KERNEL */
  81 
  82 #include "zfs_prop.h"
  83 #include "zfs_comutil.h"
  84 
  85 /*
  86  * The interval, in seconds, at which failed configuration cache file writes
  87  * should be retried.
  88  */
  89 static int zfs_ccw_retry_interval = 300;
  90 
  91 typedef enum zti_modes {
  92         ZTI_MODE_FIXED,                 /* value is # of threads (min 1) */
  93         ZTI_MODE_BATCH,                 /* cpu-intensive; value is ignored */
  94         ZTI_MODE_NULL,                  /* don't create a taskq */
  95         ZTI_NMODES
  96 } zti_modes_t;
  97 
  98 #define ZTI_P(n, q)     { ZTI_MODE_FIXED, (n), (q) }
  99 #define ZTI_BATCH       { ZTI_MODE_BATCH, 0, 1 }
 100 #define ZTI_NULL        { ZTI_MODE_NULL, 0, 0 }
 101 
 102 #define ZTI_N(n)        ZTI_P(n, 1)
 103 #define ZTI_ONE         ZTI_N(1)
 104 
 105 typedef struct zio_taskq_info {
 106         zti_modes_t zti_mode;
 107         uint_t zti_value;
 108         uint_t zti_count;
 109 } zio_taskq_info_t;
 110 
 111 static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
 112         "issue", "issue_high", "intr", "intr_high"
 113 };
 114 
 115 /*
 116  * This table defines the taskq settings for each ZFS I/O type. When
 117  * initializing a pool, we use this table to create an appropriately sized
 118  * taskq. Some operations are low volume and therefore have a small, static
 119  * number of threads assigned to their taskqs using the ZTI_N(#) or ZTI_ONE
 120  * macros. Other operations process a large amount of data; the ZTI_BATCH
 121  * macro causes us to create a taskq oriented for throughput. Some operations
 122  * are so high frequency and short-lived that the taskq itself can become a a
 123  * point of lock contention. The ZTI_P(#, #) macro indicates that we need an
 124  * additional degree of parallelism specified by the number of threads per-
 125  * taskq and the number of taskqs; when dispatching an event in this case, the
 126  * particular taskq is chosen at random.
 127  *
 128  * The different taskq priorities are to handle the different contexts (issue
 129  * and interrupt) and then to reserve threads for ZIO_PRIORITY_NOW I/Os that
 130  * need to be handled with minimum delay.
 131  */
 132 const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
 133         /* ISSUE        ISSUE_HIGH      INTR            INTR_HIGH */
 134         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* NULL */
 135         { ZTI_N(8),     ZTI_NULL,       ZTI_P(12, 8),   ZTI_NULL }, /* READ */
 136         { ZTI_BATCH,    ZTI_N(5),       ZTI_N(8),       ZTI_N(5) }, /* WRITE */
 137         { ZTI_P(12, 8), ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* FREE */
 138         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* CLAIM */
 139         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* IOCTL */
 140 };
 141 
 142 static void spa_sync_version(void *arg, dmu_tx_t *tx);
 143 static void spa_sync_props(void *arg, dmu_tx_t *tx);
 144 static boolean_t spa_has_active_shared_spare(spa_t *spa);
 145 static int spa_load_impl(spa_t *spa, uint64_t, nvlist_t *config,
 146     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
 147     char **ereport);
 148 static void spa_vdev_resilver_done(spa_t *spa);
 149 
 150 uint_t          zio_taskq_batch_pct = 75;       /* 1 thread per cpu in pset */
 151 id_t            zio_taskq_psrset_bind = PS_NONE;
 152 boolean_t       zio_taskq_sysdc = B_TRUE;       /* use SDC scheduling class */
 153 uint_t          zio_taskq_basedc = 80;          /* base duty cycle */
 154 
 155 boolean_t       spa_create_process = B_TRUE;    /* no process ==> no sysdc */
 156 extern int      zfs_sync_pass_deferred_free;
 157 
 158 /*
 159  * This (illegal) pool name is used when temporarily importing a spa_t in order
 160  * to get the vdev stats associated with the imported devices.
 161  */
 162 #define TRYIMPORT_NAME  "$import"
 163 
 164 /*
 165  * ==========================================================================
 166  * SPA properties routines
 167  * ==========================================================================
 168  */
 169 
 170 /*
 171  * Add a (source=src, propname=propval) list to an nvlist.
 172  */
 173 static void
 174 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, char *strval,
 175     uint64_t intval, zprop_source_t src)
 176 {
 177         const char *propname = zpool_prop_to_name(prop);
 178         nvlist_t *propval;
 179 
 180         VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 181         VERIFY(nvlist_add_uint64(propval, ZPROP_SOURCE, src) == 0);
 182 
 183         if (strval != NULL)
 184                 VERIFY(nvlist_add_string(propval, ZPROP_VALUE, strval) == 0);
 185         else
 186                 VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, intval) == 0);
 187 
 188         VERIFY(nvlist_add_nvlist(nvl, propname, propval) == 0);
 189         nvlist_free(propval);
 190 }
 191 
 192 /*
 193  * Get property values from the spa configuration.
 194  */
 195 static void
 196 spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
 197 {
 198         vdev_t *rvd = spa->spa_root_vdev;
 199         dsl_pool_t *pool = spa->spa_dsl_pool;
 200         uint64_t size, alloc, cap, version;
 201         zprop_source_t src = ZPROP_SRC_NONE;
 202         spa_config_dirent_t *dp;
 203         metaslab_class_t *mc = spa_normal_class(spa);
 204 
 205         ASSERT(MUTEX_HELD(&spa->spa_props_lock));
 206 
 207         if (rvd != NULL) {
 208                 alloc = metaslab_class_get_alloc(spa_normal_class(spa));
 209                 size = metaslab_class_get_space(spa_normal_class(spa));
 210                 spa_prop_add_list(*nvp, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
 211                 spa_prop_add_list(*nvp, ZPOOL_PROP_SIZE, NULL, size, src);
 212                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALLOCATED, NULL, alloc, src);
 213                 spa_prop_add_list(*nvp, ZPOOL_PROP_FREE, NULL,
 214                     size - alloc, src);
 215 
 216                 spa_prop_add_list(*nvp, ZPOOL_PROP_FRAGMENTATION, NULL,
 217                     metaslab_class_fragmentation(mc), src);
 218                 spa_prop_add_list(*nvp, ZPOOL_PROP_EXPANDSZ, NULL,
 219                     metaslab_class_expandable_space(mc), src);
 220                 spa_prop_add_list(*nvp, ZPOOL_PROP_READONLY, NULL,
 221                     (spa_mode(spa) == FREAD), src);
 222 
 223                 cap = (size == 0) ? 0 : (alloc * 100 / size);
 224                 spa_prop_add_list(*nvp, ZPOOL_PROP_CAPACITY, NULL, cap, src);
 225 
 226                 spa_prop_add_list(*nvp, ZPOOL_PROP_DEDUPRATIO, NULL,
 227                     ddt_get_pool_dedup_ratio(spa), src);
 228 
 229                 spa_prop_add_list(*nvp, ZPOOL_PROP_HEALTH, NULL,
 230                     rvd->vdev_state, src);
 231 
 232                 version = spa_version(spa);
 233                 if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION))
 234                         src = ZPROP_SRC_DEFAULT;
 235                 else
 236                         src = ZPROP_SRC_LOCAL;
 237                 spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL, version, src);
 238         }
 239 
 240         if (pool != NULL) {
 241                 /*
 242                  * The $FREE directory was introduced in SPA_VERSION_DEADLISTS,
 243                  * when opening pools before this version freedir will be NULL.
 244                  */
 245                 if (pool->dp_free_dir != NULL) {
 246                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING, NULL,
 247                             dsl_dir_phys(pool->dp_free_dir)->dd_used_bytes,
 248                             src);
 249                 } else {
 250                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING,
 251                             NULL, 0, src);
 252                 }
 253 
 254                 if (pool->dp_leak_dir != NULL) {
 255                         spa_prop_add_list(*nvp, ZPOOL_PROP_LEAKED, NULL,
 256                             dsl_dir_phys(pool->dp_leak_dir)->dd_used_bytes,
 257                             src);
 258                 } else {
 259                         spa_prop_add_list(*nvp, ZPOOL_PROP_LEAKED,
 260                             NULL, 0, src);
 261                 }
 262         }
 263 
 264         spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
 265 
 266         if (spa->spa_comment != NULL) {
 267                 spa_prop_add_list(*nvp, ZPOOL_PROP_COMMENT, spa->spa_comment,
 268                     0, ZPROP_SRC_LOCAL);
 269         }
 270 
 271         if (spa->spa_root != NULL)
 272                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
 273                     0, ZPROP_SRC_LOCAL);
 274 
 275         if (spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_BLOCKS)) {
 276                 spa_prop_add_list(*nvp, ZPOOL_PROP_MAXBLOCKSIZE, NULL,
 277                     MIN(zfs_max_recordsize, SPA_MAXBLOCKSIZE), ZPROP_SRC_NONE);
 278         } else {
 279                 spa_prop_add_list(*nvp, ZPOOL_PROP_MAXBLOCKSIZE, NULL,
 280                     SPA_OLD_MAXBLOCKSIZE, ZPROP_SRC_NONE);
 281         }
 282 
 283         if ((dp = list_head(&spa->spa_config_list)) != NULL) {
 284                 if (dp->scd_path == NULL) {
 285                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 286                             "none", 0, ZPROP_SRC_LOCAL);
 287                 } else if (strcmp(dp->scd_path, spa_config_path) != 0) {
 288                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 289                             dp->scd_path, 0, ZPROP_SRC_LOCAL);
 290                 }
 291         }
 292 }
 293 
 294 /*
 295  * Get zpool property values.
 296  */
 297 int
 298 spa_prop_get(spa_t *spa, nvlist_t **nvp)
 299 {
 300         objset_t *mos = spa->spa_meta_objset;
 301         zap_cursor_t zc;
 302         zap_attribute_t za;
 303         int err;
 304 
 305         VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 306 
 307         mutex_enter(&spa->spa_props_lock);
 308 
 309         /*
 310          * Get properties from the spa config.
 311          */
 312         spa_prop_get_config(spa, nvp);
 313 
 314         /* If no pool property object, no more prop to get. */
 315         if (mos == NULL || spa->spa_pool_props_object == 0) {
 316                 mutex_exit(&spa->spa_props_lock);
 317                 return (0);
 318         }
 319 
 320         /*
 321          * Get properties from the MOS pool property object.
 322          */
 323         for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
 324             (err = zap_cursor_retrieve(&zc, &za)) == 0;
 325             zap_cursor_advance(&zc)) {
 326                 uint64_t intval = 0;
 327                 char *strval = NULL;
 328                 zprop_source_t src = ZPROP_SRC_DEFAULT;
 329                 zpool_prop_t prop;
 330 
 331                 if ((prop = zpool_name_to_prop(za.za_name)) == ZPROP_INVAL)
 332                         continue;
 333 
 334                 switch (za.za_integer_length) {
 335                 case 8:
 336                         /* integer property */
 337                         if (za.za_first_integer !=
 338                             zpool_prop_default_numeric(prop))
 339                                 src = ZPROP_SRC_LOCAL;
 340 
 341                         if (prop == ZPOOL_PROP_BOOTFS) {
 342                                 dsl_pool_t *dp;
 343                                 dsl_dataset_t *ds = NULL;
 344 
 345                                 dp = spa_get_dsl(spa);
 346                                 dsl_pool_config_enter(dp, FTAG);
 347                                 if (err = dsl_dataset_hold_obj(dp,
 348                                     za.za_first_integer, FTAG, &ds)) {
 349                                         dsl_pool_config_exit(dp, FTAG);
 350                                         break;
 351                                 }
 352 
 353                                 strval = kmem_alloc(
 354                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1,
 355                                     KM_SLEEP);
 356                                 dsl_dataset_name(ds, strval);
 357                                 dsl_dataset_rele(ds, FTAG);
 358                                 dsl_pool_config_exit(dp, FTAG);
 359                         } else {
 360                                 strval = NULL;
 361                                 intval = za.za_first_integer;
 362                         }
 363 
 364                         spa_prop_add_list(*nvp, prop, strval, intval, src);
 365 
 366                         if (strval != NULL)
 367                                 kmem_free(strval,
 368                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1);
 369 
 370                         break;
 371 
 372                 case 1:
 373                         /* string property */
 374                         strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
 375                         err = zap_lookup(mos, spa->spa_pool_props_object,
 376                             za.za_name, 1, za.za_num_integers, strval);
 377                         if (err) {
 378                                 kmem_free(strval, za.za_num_integers);
 379                                 break;
 380                         }
 381                         spa_prop_add_list(*nvp, prop, strval, 0, src);
 382                         kmem_free(strval, za.za_num_integers);
 383                         break;
 384 
 385                 default:
 386                         break;
 387                 }
 388         }
 389         zap_cursor_fini(&zc);
 390         mutex_exit(&spa->spa_props_lock);
 391 out:
 392         if (err && err != ENOENT) {
 393                 nvlist_free(*nvp);
 394                 *nvp = NULL;
 395                 return (err);
 396         }
 397 
 398         return (0);
 399 }
 400 
 401 /*
 402  * Validate the given pool properties nvlist and modify the list
 403  * for the property values to be set.
 404  */
 405 static int
 406 spa_prop_validate(spa_t *spa, nvlist_t *props)
 407 {
 408         nvpair_t *elem;
 409         int error = 0, reset_bootfs = 0;
 410         uint64_t objnum = 0;
 411         boolean_t has_feature = B_FALSE;
 412 
 413         elem = NULL;
 414         while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
 415                 uint64_t intval;
 416                 char *strval, *slash, *check, *fname;
 417                 const char *propname = nvpair_name(elem);
 418                 zpool_prop_t prop = zpool_name_to_prop(propname);
 419 
 420                 switch (prop) {
 421                 case ZPROP_INVAL:
 422                         if (!zpool_prop_feature(propname)) {
 423                                 error = SET_ERROR(EINVAL);
 424                                 break;
 425                         }
 426 
 427                         /*
 428                          * Sanitize the input.
 429                          */
 430                         if (nvpair_type(elem) != DATA_TYPE_UINT64) {
 431                                 error = SET_ERROR(EINVAL);
 432                                 break;
 433                         }
 434 
 435                         if (nvpair_value_uint64(elem, &intval) != 0) {
 436                                 error = SET_ERROR(EINVAL);
 437                                 break;
 438                         }
 439 
 440                         if (intval != 0) {
 441                                 error = SET_ERROR(EINVAL);
 442                                 break;
 443                         }
 444 
 445                         fname = strchr(propname, '@') + 1;
 446                         if (zfeature_lookup_name(fname, NULL) != 0) {
 447                                 error = SET_ERROR(EINVAL);
 448                                 break;
 449                         }
 450 
 451                         has_feature = B_TRUE;
 452                         break;
 453 
 454                 case ZPOOL_PROP_VERSION:
 455                         error = nvpair_value_uint64(elem, &intval);
 456                         if (!error &&
 457                             (intval < spa_version(spa) ||
 458                             intval > SPA_VERSION_BEFORE_FEATURES ||
 459                             has_feature))
 460                                 error = SET_ERROR(EINVAL);
 461                         break;
 462 
 463                 case ZPOOL_PROP_DELEGATION:
 464                 case ZPOOL_PROP_AUTOREPLACE:
 465                 case ZPOOL_PROP_LISTSNAPS:
 466                 case ZPOOL_PROP_AUTOEXPAND:
 467                         error = nvpair_value_uint64(elem, &intval);
 468                         if (!error && intval > 1)
 469                                 error = SET_ERROR(EINVAL);
 470                         break;
 471 
 472                 case ZPOOL_PROP_BOOTFS:
 473                         /*
 474                          * If the pool version is less than SPA_VERSION_BOOTFS,
 475                          * or the pool is still being created (version == 0),
 476                          * the bootfs property cannot be set.
 477                          */
 478                         if (spa_version(spa) < SPA_VERSION_BOOTFS) {
 479                                 error = SET_ERROR(ENOTSUP);
 480                                 break;
 481                         }
 482 
 483                         /*
 484                          * Make sure the vdev config is bootable
 485                          */
 486                         if (!vdev_is_bootable(spa->spa_root_vdev)) {
 487                                 error = SET_ERROR(ENOTSUP);
 488                                 break;
 489                         }
 490 
 491                         reset_bootfs = 1;
 492 
 493                         error = nvpair_value_string(elem, &strval);
 494 
 495                         if (!error) {
 496                                 objset_t *os;
 497                                 uint64_t propval;
 498 
 499                                 if (strval == NULL || strval[0] == '\0') {
 500                                         objnum = zpool_prop_default_numeric(
 501                                             ZPOOL_PROP_BOOTFS);
 502                                         break;
 503                                 }
 504 
 505                                 if (error = dmu_objset_hold(strval, FTAG, &os))
 506                                         break;
 507 
 508                                 /*
 509                                  * Must be ZPL, and its property settings
 510                                  * must be supported by GRUB (compression
 511                                  * is not gzip, and large blocks are not used).
 512                                  */
 513 
 514                                 if (dmu_objset_type(os) != DMU_OST_ZFS) {
 515                                         error = SET_ERROR(ENOTSUP);
 516                                 } else if ((error =
 517                                     dsl_prop_get_int_ds(dmu_objset_ds(os),
 518                                     zfs_prop_to_name(ZFS_PROP_COMPRESSION),
 519                                     &propval)) == 0 &&
 520                                     !BOOTFS_COMPRESS_VALID(propval)) {
 521                                         error = SET_ERROR(ENOTSUP);
 522                                 } else if ((error =
 523                                     dsl_prop_get_int_ds(dmu_objset_ds(os),
 524                                     zfs_prop_to_name(ZFS_PROP_RECORDSIZE),
 525                                     &propval)) == 0 &&
 526                                     propval > SPA_OLD_MAXBLOCKSIZE) {
 527                                         error = SET_ERROR(ENOTSUP);
 528                                 } else {
 529                                         objnum = dmu_objset_id(os);
 530                                 }
 531                                 dmu_objset_rele(os, FTAG);
 532                         }
 533                         break;
 534 
 535                 case ZPOOL_PROP_FAILUREMODE:
 536                         error = nvpair_value_uint64(elem, &intval);
 537                         if (!error && (intval < ZIO_FAILURE_MODE_WAIT ||
 538                             intval > ZIO_FAILURE_MODE_PANIC))
 539                                 error = SET_ERROR(EINVAL);
 540 
 541                         /*
 542                          * This is a special case which only occurs when
 543                          * the pool has completely failed. This allows
 544                          * the user to change the in-core failmode property
 545                          * without syncing it out to disk (I/Os might
 546                          * currently be blocked). We do this by returning
 547                          * EIO to the caller (spa_prop_set) to trick it
 548                          * into thinking we encountered a property validation
 549                          * error.
 550                          */
 551                         if (!error && spa_suspended(spa)) {
 552                                 spa->spa_failmode = intval;
 553                                 error = SET_ERROR(EIO);
 554                         }
 555                         break;
 556 
 557                 case ZPOOL_PROP_CACHEFILE:
 558                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 559                                 break;
 560 
 561                         if (strval[0] == '\0')
 562                                 break;
 563 
 564                         if (strcmp(strval, "none") == 0)
 565                                 break;
 566 
 567                         if (strval[0] != '/') {
 568                                 error = SET_ERROR(EINVAL);
 569                                 break;
 570                         }
 571 
 572                         slash = strrchr(strval, '/');
 573                         ASSERT(slash != NULL);
 574 
 575                         if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
 576                             strcmp(slash, "/..") == 0)
 577                                 error = SET_ERROR(EINVAL);
 578                         break;
 579 
 580                 case ZPOOL_PROP_COMMENT:
 581                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 582                                 break;
 583                         for (check = strval; *check != '\0'; check++) {
 584                                 /*
 585                                  * The kernel doesn't have an easy isprint()
 586                                  * check.  For this kernel check, we merely
 587                                  * check ASCII apart from DEL.  Fix this if
 588                                  * there is an easy-to-use kernel isprint().
 589                                  */
 590                                 if (*check >= 0x7f) {
 591                                         error = SET_ERROR(EINVAL);
 592                                         break;
 593                                 }
 594                         }
 595                         if (strlen(strval) > ZPROP_MAX_COMMENT)
 596                                 error = E2BIG;
 597                         break;
 598 
 599                 case ZPOOL_PROP_DEDUPDITTO:
 600                         if (spa_version(spa) < SPA_VERSION_DEDUP)
 601                                 error = SET_ERROR(ENOTSUP);
 602                         else
 603                                 error = nvpair_value_uint64(elem, &intval);
 604                         if (error == 0 &&
 605                             intval != 0 && intval < ZIO_DEDUPDITTO_MIN)
 606                                 error = SET_ERROR(EINVAL);
 607                         break;
 608                 }
 609 
 610                 if (error)
 611                         break;
 612         }
 613 
 614         if (!error && reset_bootfs) {
 615                 error = nvlist_remove(props,
 616                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
 617 
 618                 if (!error) {
 619                         error = nvlist_add_uint64(props,
 620                             zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
 621                 }
 622         }
 623 
 624         return (error);
 625 }
 626 
 627 void
 628 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
 629 {
 630         char *cachefile;
 631         spa_config_dirent_t *dp;
 632 
 633         if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
 634             &cachefile) != 0)
 635                 return;
 636 
 637         dp = kmem_alloc(sizeof (spa_config_dirent_t),
 638             KM_SLEEP);
 639 
 640         if (cachefile[0] == '\0')
 641                 dp->scd_path = spa_strdup(spa_config_path);
 642         else if (strcmp(cachefile, "none") == 0)
 643                 dp->scd_path = NULL;
 644         else
 645                 dp->scd_path = spa_strdup(cachefile);
 646 
 647         list_insert_head(&spa->spa_config_list, dp);
 648         if (need_sync)
 649                 spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
 650 }
 651 
 652 int
 653 spa_prop_set(spa_t *spa, nvlist_t *nvp)
 654 {
 655         int error;
 656         nvpair_t *elem = NULL;
 657         boolean_t need_sync = B_FALSE;
 658 
 659         if ((error = spa_prop_validate(spa, nvp)) != 0)
 660                 return (error);
 661 
 662         while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
 663                 zpool_prop_t prop = zpool_name_to_prop(nvpair_name(elem));
 664 
 665                 if (prop == ZPOOL_PROP_CACHEFILE ||
 666                     prop == ZPOOL_PROP_ALTROOT ||
 667                     prop == ZPOOL_PROP_READONLY)
 668                         continue;
 669 
 670                 if (prop == ZPOOL_PROP_VERSION || prop == ZPROP_INVAL) {
 671                         uint64_t ver;
 672 
 673                         if (prop == ZPOOL_PROP_VERSION) {
 674                                 VERIFY(nvpair_value_uint64(elem, &ver) == 0);
 675                         } else {
 676                                 ASSERT(zpool_prop_feature(nvpair_name(elem)));
 677                                 ver = SPA_VERSION_FEATURES;
 678                                 need_sync = B_TRUE;
 679                         }
 680 
 681                         /* Save time if the version is already set. */
 682                         if (ver == spa_version(spa))
 683                                 continue;
 684 
 685                         /*
 686                          * In addition to the pool directory object, we might
 687                          * create the pool properties object, the features for
 688                          * read object, the features for write object, or the
 689                          * feature descriptions object.
 690                          */
 691                         error = dsl_sync_task(spa->spa_name, NULL,
 692                             spa_sync_version, &ver,
 693                             6, ZFS_SPACE_CHECK_RESERVED);
 694                         if (error)
 695                                 return (error);
 696                         continue;
 697                 }
 698 
 699                 need_sync = B_TRUE;
 700                 break;
 701         }
 702 
 703         if (need_sync) {
 704                 return (dsl_sync_task(spa->spa_name, NULL, spa_sync_props,
 705                     nvp, 6, ZFS_SPACE_CHECK_RESERVED));
 706         }
 707 
 708         return (0);
 709 }
 710 
 711 /*
 712  * If the bootfs property value is dsobj, clear it.
 713  */
 714 void
 715 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
 716 {
 717         if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
 718                 VERIFY(zap_remove(spa->spa_meta_objset,
 719                     spa->spa_pool_props_object,
 720                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
 721                 spa->spa_bootfs = 0;
 722         }
 723 }
 724 
 725 /*ARGSUSED*/
 726 static int
 727 spa_change_guid_check(void *arg, dmu_tx_t *tx)
 728 {
 729         uint64_t *newguid = arg;
 730         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 731         vdev_t *rvd = spa->spa_root_vdev;
 732         uint64_t vdev_state;
 733 
 734         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
 735         vdev_state = rvd->vdev_state;
 736         spa_config_exit(spa, SCL_STATE, FTAG);
 737 
 738         if (vdev_state != VDEV_STATE_HEALTHY)
 739                 return (SET_ERROR(ENXIO));
 740 
 741         ASSERT3U(spa_guid(spa), !=, *newguid);
 742 
 743         return (0);
 744 }
 745 
 746 static void
 747 spa_change_guid_sync(void *arg, dmu_tx_t *tx)
 748 {
 749         uint64_t *newguid = arg;
 750         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 751         uint64_t oldguid;
 752         vdev_t *rvd = spa->spa_root_vdev;
 753 
 754         oldguid = spa_guid(spa);
 755 
 756         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
 757         rvd->vdev_guid = *newguid;
 758         rvd->vdev_guid_sum += (*newguid - oldguid);
 759         vdev_config_dirty(rvd);
 760         spa_config_exit(spa, SCL_STATE, FTAG);
 761 
 762         spa_history_log_internal(spa, "guid change", tx, "old=%llu new=%llu",
 763             oldguid, *newguid);
 764 }
 765 
 766 /*
 767  * Change the GUID for the pool.  This is done so that we can later
 768  * re-import a pool built from a clone of our own vdevs.  We will modify
 769  * the root vdev's guid, our own pool guid, and then mark all of our
 770  * vdevs dirty.  Note that we must make sure that all our vdevs are
 771  * online when we do this, or else any vdevs that weren't present
 772  * would be orphaned from our pool.  We are also going to issue a
 773  * sysevent to update any watchers.
 774  */
 775 int
 776 spa_change_guid(spa_t *spa)
 777 {
 778         int error;
 779         uint64_t guid;
 780 
 781         mutex_enter(&spa->spa_vdev_top_lock);
 782         mutex_enter(&spa_namespace_lock);
 783         guid = spa_generate_guid(NULL);
 784 
 785         error = dsl_sync_task(spa->spa_name, spa_change_guid_check,
 786             spa_change_guid_sync, &guid, 5, ZFS_SPACE_CHECK_RESERVED);
 787 
 788         if (error == 0) {
 789                 spa_config_sync(spa, B_FALSE, B_TRUE);
 790                 spa_event_notify(spa, NULL, ESC_ZFS_POOL_REGUID);
 791         }
 792 
 793         mutex_exit(&spa_namespace_lock);
 794         mutex_exit(&spa->spa_vdev_top_lock);
 795 
 796         return (error);
 797 }
 798 
 799 /*
 800  * ==========================================================================
 801  * SPA state manipulation (open/create/destroy/import/export)
 802  * ==========================================================================
 803  */
 804 
 805 static int
 806 spa_error_entry_compare(const void *a, const void *b)
 807 {
 808         spa_error_entry_t *sa = (spa_error_entry_t *)a;
 809         spa_error_entry_t *sb = (spa_error_entry_t *)b;
 810         int ret;
 811 
 812         ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
 813             sizeof (zbookmark_phys_t));
 814 
 815         if (ret < 0)
 816                 return (-1);
 817         else if (ret > 0)
 818                 return (1);
 819         else
 820                 return (0);
 821 }
 822 
 823 /*
 824  * Utility function which retrieves copies of the current logs and
 825  * re-initializes them in the process.
 826  */
 827 void
 828 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
 829 {
 830         ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
 831 
 832         bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
 833         bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));
 834 
 835         avl_create(&spa->spa_errlist_scrub,
 836             spa_error_entry_compare, sizeof (spa_error_entry_t),
 837             offsetof(spa_error_entry_t, se_avl));
 838         avl_create(&spa->spa_errlist_last,
 839             spa_error_entry_compare, sizeof (spa_error_entry_t),
 840             offsetof(spa_error_entry_t, se_avl));
 841 }
 842 
 843 static void
 844 spa_taskqs_init(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
 845 {
 846         const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
 847         enum zti_modes mode = ztip->zti_mode;
 848         uint_t value = ztip->zti_value;
 849         uint_t count = ztip->zti_count;
 850         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 851         char name[32];
 852         uint_t flags = 0;
 853         boolean_t batch = B_FALSE;
 854 
 855         if (mode == ZTI_MODE_NULL) {
 856                 tqs->stqs_count = 0;
 857                 tqs->stqs_taskq = NULL;
 858                 return;
 859         }
 860 
 861         ASSERT3U(count, >, 0);
 862 
 863         tqs->stqs_count = count;
 864         tqs->stqs_taskq = kmem_alloc(count * sizeof (taskq_t *), KM_SLEEP);
 865 
 866         switch (mode) {
 867         case ZTI_MODE_FIXED:
 868                 ASSERT3U(value, >=, 1);
 869                 value = MAX(value, 1);
 870                 break;
 871 
 872         case ZTI_MODE_BATCH:
 873                 batch = B_TRUE;
 874                 flags |= TASKQ_THREADS_CPU_PCT;
 875                 value = zio_taskq_batch_pct;
 876                 break;
 877 
 878         default:
 879                 panic("unrecognized mode for %s_%s taskq (%u:%u) in "
 880                     "spa_activate()",
 881                     zio_type_name[t], zio_taskq_types[q], mode, value);
 882                 break;
 883         }
 884 
 885         for (uint_t i = 0; i < count; i++) {
 886                 taskq_t *tq;
 887 
 888                 if (count > 1) {
 889                         (void) snprintf(name, sizeof (name), "%s_%s_%u",
 890                             zio_type_name[t], zio_taskq_types[q], i);
 891                 } else {
 892                         (void) snprintf(name, sizeof (name), "%s_%s",
 893                             zio_type_name[t], zio_taskq_types[q]);
 894                 }
 895 
 896                 if (zio_taskq_sysdc && spa->spa_proc != &p0) {
 897                         if (batch)
 898                                 flags |= TASKQ_DC_BATCH;
 899 
 900                         tq = taskq_create_sysdc(name, value, 50, INT_MAX,
 901                             spa->spa_proc, zio_taskq_basedc, flags);
 902                 } else {
 903                         pri_t pri = maxclsyspri;
 904                         /*
 905                          * The write issue taskq can be extremely CPU
 906                          * intensive.  Run it at slightly lower priority
 907                          * than the other taskqs.
 908                          */
 909                         if (t == ZIO_TYPE_WRITE && q == ZIO_TASKQ_ISSUE)
 910                                 pri--;
 911 
 912                         tq = taskq_create_proc(name, value, pri, 50,
 913                             INT_MAX, spa->spa_proc, flags);
 914                 }
 915 
 916                 tqs->stqs_taskq[i] = tq;
 917         }
 918 }
 919 
 920 static void
 921 spa_taskqs_fini(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
 922 {
 923         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 924 
 925         if (tqs->stqs_taskq == NULL) {
 926                 ASSERT0(tqs->stqs_count);
 927                 return;
 928         }
 929 
 930         for (uint_t i = 0; i < tqs->stqs_count; i++) {
 931                 ASSERT3P(tqs->stqs_taskq[i], !=, NULL);
 932                 taskq_destroy(tqs->stqs_taskq[i]);
 933         }
 934 
 935         kmem_free(tqs->stqs_taskq, tqs->stqs_count * sizeof (taskq_t *));
 936         tqs->stqs_taskq = NULL;
 937 }
 938 
 939 /*
 940  * Dispatch a task to the appropriate taskq for the ZFS I/O type and priority.
 941  * Note that a type may have multiple discrete taskqs to avoid lock contention
 942  * on the taskq itself. In that case we choose which taskq at random by using
 943  * the low bits of gethrtime().
 944  */
 945 void
 946 spa_taskq_dispatch_ent(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
 947     task_func_t *func, void *arg, uint_t flags, taskq_ent_t *ent)
 948 {
 949         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 950         taskq_t *tq;
 951 
 952         ASSERT3P(tqs->stqs_taskq, !=, NULL);
 953         ASSERT3U(tqs->stqs_count, !=, 0);
 954 
 955         if (tqs->stqs_count == 1) {
 956                 tq = tqs->stqs_taskq[0];
 957         } else {
 958                 tq = tqs->stqs_taskq[gethrtime() % tqs->stqs_count];
 959         }
 960 
 961         taskq_dispatch_ent(tq, func, arg, flags, ent);
 962 }
 963 
 964 static void
 965 spa_create_zio_taskqs(spa_t *spa)
 966 {
 967         for (int t = 0; t < ZIO_TYPES; t++) {
 968                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
 969                         spa_taskqs_init(spa, t, q);
 970                 }
 971         }
 972 }
 973 
 974 #ifdef _KERNEL
 975 static void
 976 spa_thread(void *arg)
 977 {
 978         callb_cpr_t cprinfo;
 979 
 980         spa_t *spa = arg;
 981         user_t *pu = PTOU(curproc);
 982 
 983         CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
 984             spa->spa_name);
 985 
 986         ASSERT(curproc != &p0);
 987         (void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
 988             "zpool-%s", spa->spa_name);
 989         (void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
 990 
 991         /* bind this thread to the requested psrset */
 992         if (zio_taskq_psrset_bind != PS_NONE) {
 993                 pool_lock();
 994                 mutex_enter(&cpu_lock);
 995                 mutex_enter(&pidlock);
 996                 mutex_enter(&curproc->p_lock);
 997 
 998                 if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
 999                     0, NULL, NULL) == 0)  {
1000                         curthread->t_bind_pset = zio_taskq_psrset_bind;
1001                 } else {
1002                         cmn_err(CE_WARN,
1003                             "Couldn't bind process for zfs pool \"%s\" to "
1004                             "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
1005                 }
1006 
1007                 mutex_exit(&curproc->p_lock);
1008                 mutex_exit(&pidlock);
1009                 mutex_exit(&cpu_lock);
1010                 pool_unlock();
1011         }
1012 
1013         if (zio_taskq_sysdc) {
1014                 sysdc_thread_enter(curthread, 100, 0);
1015         }
1016 
1017         spa->spa_proc = curproc;
1018         spa->spa_did = curthread->t_did;
1019 
1020         spa_create_zio_taskqs(spa);
1021 
1022         mutex_enter(&spa->spa_proc_lock);
1023         ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
1024 
1025         spa->spa_proc_state = SPA_PROC_ACTIVE;
1026         cv_broadcast(&spa->spa_proc_cv);
1027 
1028         CALLB_CPR_SAFE_BEGIN(&cprinfo);
1029         while (spa->spa_proc_state == SPA_PROC_ACTIVE)
1030                 cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1031         CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
1032 
1033         ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
1034         spa->spa_proc_state = SPA_PROC_GONE;
1035         spa->spa_proc = &p0;
1036         cv_broadcast(&spa->spa_proc_cv);
1037         CALLB_CPR_EXIT(&cprinfo);   /* drops spa_proc_lock */
1038 
1039         mutex_enter(&curproc->p_lock);
1040         lwp_exit();
1041 }
1042 #endif
1043 
1044 /*
1045  * Activate an uninitialized pool.
1046  */
1047 static void
1048 spa_activate(spa_t *spa, int mode)
1049 {
1050         ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
1051 
1052         spa->spa_state = POOL_STATE_ACTIVE;
1053         spa->spa_mode = mode;
1054 
1055         spa->spa_normal_class = metaslab_class_create(spa, zfs_metaslab_ops);
1056         spa->spa_log_class = metaslab_class_create(spa, zfs_metaslab_ops);
1057 
1058         /* Try to create a covering process */
1059         mutex_enter(&spa->spa_proc_lock);
1060         ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
1061         ASSERT(spa->spa_proc == &p0);
1062         spa->spa_did = 0;
1063 
1064         /* Only create a process if we're going to be around a while. */
1065         if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
1066                 if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
1067                     NULL, 0) == 0) {
1068                         spa->spa_proc_state = SPA_PROC_CREATED;
1069                         while (spa->spa_proc_state == SPA_PROC_CREATED) {
1070                                 cv_wait(&spa->spa_proc_cv,
1071                                     &spa->spa_proc_lock);
1072                         }
1073                         ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1074                         ASSERT(spa->spa_proc != &p0);
1075                         ASSERT(spa->spa_did != 0);
1076                 } else {
1077 #ifdef _KERNEL
1078                         cmn_err(CE_WARN,
1079                             "Couldn't create process for zfs pool \"%s\"\n",
1080                             spa->spa_name);
1081 #endif
1082                 }
1083         }
1084         mutex_exit(&spa->spa_proc_lock);
1085 
1086         /* If we didn't create a process, we need to create our taskqs. */
1087         if (spa->spa_proc == &p0) {
1088                 spa_create_zio_taskqs(spa);
1089         }
1090 
1091         list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
1092             offsetof(vdev_t, vdev_config_dirty_node));
1093         list_create(&spa->spa_evicting_os_list, sizeof (objset_t),
1094             offsetof(objset_t, os_evicting_node));
1095         list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
1096             offsetof(vdev_t, vdev_state_dirty_node));
1097 
1098         txg_list_create(&spa->spa_vdev_txg_list,
1099             offsetof(struct vdev, vdev_txg_node));
1100 
1101         avl_create(&spa->spa_errlist_scrub,
1102             spa_error_entry_compare, sizeof (spa_error_entry_t),
1103             offsetof(spa_error_entry_t, se_avl));
1104         avl_create(&spa->spa_errlist_last,
1105             spa_error_entry_compare, sizeof (spa_error_entry_t),
1106             offsetof(spa_error_entry_t, se_avl));
1107 }
1108 
1109 /*
1110  * Opposite of spa_activate().
1111  */
1112 static void
1113 spa_deactivate(spa_t *spa)
1114 {
1115         ASSERT(spa->spa_sync_on == B_FALSE);
1116         ASSERT(spa->spa_dsl_pool == NULL);
1117         ASSERT(spa->spa_root_vdev == NULL);
1118         ASSERT(spa->spa_async_zio_root == NULL);
1119         ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
1120 
1121         spa_evicting_os_wait(spa);
1122 
1123         txg_list_destroy(&spa->spa_vdev_txg_list);
1124 
1125         list_destroy(&spa->spa_config_dirty_list);
1126         list_destroy(&spa->spa_evicting_os_list);
1127         list_destroy(&spa->spa_state_dirty_list);
1128 
1129         for (int t = 0; t < ZIO_TYPES; t++) {
1130                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
1131                         spa_taskqs_fini(spa, t, q);
1132                 }
1133         }
1134 
1135         metaslab_class_destroy(spa->spa_normal_class);
1136         spa->spa_normal_class = NULL;
1137 
1138         metaslab_class_destroy(spa->spa_log_class);
1139         spa->spa_log_class = NULL;
1140 
1141         /*
1142          * If this was part of an import or the open otherwise failed, we may
1143          * still have errors left in the queues.  Empty them just in case.
1144          */
1145         spa_errlog_drain(spa);
1146 
1147         avl_destroy(&spa->spa_errlist_scrub);
1148         avl_destroy(&spa->spa_errlist_last);
1149 
1150         spa->spa_state = POOL_STATE_UNINITIALIZED;
1151 
1152         mutex_enter(&spa->spa_proc_lock);
1153         if (spa->spa_proc_state != SPA_PROC_NONE) {
1154                 ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1155                 spa->spa_proc_state = SPA_PROC_DEACTIVATE;
1156                 cv_broadcast(&spa->spa_proc_cv);
1157                 while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
1158                         ASSERT(spa->spa_proc != &p0);
1159                         cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1160                 }
1161                 ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
1162                 spa->spa_proc_state = SPA_PROC_NONE;
1163         }
1164         ASSERT(spa->spa_proc == &p0);
1165         mutex_exit(&spa->spa_proc_lock);
1166 
1167         /*
1168          * We want to make sure spa_thread() has actually exited the ZFS
1169          * module, so that the module can't be unloaded out from underneath
1170          * it.
1171          */
1172         if (spa->spa_did != 0) {
1173                 thread_join(spa->spa_did);
1174                 spa->spa_did = 0;
1175         }
1176 }
1177 
1178 /*
1179  * Verify a pool configuration, and construct the vdev tree appropriately.  This
1180  * will create all the necessary vdevs in the appropriate layout, with each vdev
1181  * in the CLOSED state.  This will prep the pool before open/creation/import.
1182  * All vdev validation is done by the vdev_alloc() routine.
1183  */
1184 static int
1185 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
1186     uint_t id, int atype)
1187 {
1188         nvlist_t **child;
1189         uint_t children;
1190         int error;
1191 
1192         if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
1193                 return (error);
1194 
1195         if ((*vdp)->vdev_ops->vdev_op_leaf)
1196                 return (0);
1197 
1198         error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
1199             &child, &children);
1200 
1201         if (error == ENOENT)
1202                 return (0);
1203 
1204         if (error) {
1205                 vdev_free(*vdp);
1206                 *vdp = NULL;
1207                 return (SET_ERROR(EINVAL));
1208         }
1209 
1210         for (int c = 0; c < children; c++) {
1211                 vdev_t *vd;
1212                 if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
1213                     atype)) != 0) {
1214                         vdev_free(*vdp);
1215                         *vdp = NULL;
1216                         return (error);
1217                 }
1218         }
1219 
1220         ASSERT(*vdp != NULL);
1221 
1222         return (0);
1223 }
1224 
1225 /*
1226  * Opposite of spa_load().
1227  */
1228 static void
1229 spa_unload(spa_t *spa)
1230 {
1231         int i;
1232 
1233         ASSERT(MUTEX_HELD(&spa_namespace_lock));
1234 
1235         /*
1236          * Stop async tasks.
1237          */
1238         spa_async_suspend(spa);
1239 
1240         /*
1241          * Stop syncing.
1242          */
1243         if (spa->spa_sync_on) {
1244                 txg_sync_stop(spa->spa_dsl_pool);
1245                 spa->spa_sync_on = B_FALSE;
1246         }
1247 
1248         /*
1249          * Wait for any outstanding async I/O to complete.
1250          */
1251         if (spa->spa_async_zio_root != NULL) {
1252                 for (int i = 0; i < max_ncpus; i++)
1253                         (void) zio_wait(spa->spa_async_zio_root[i]);
1254                 kmem_free(spa->spa_async_zio_root, max_ncpus * sizeof (void *));
1255                 spa->spa_async_zio_root = NULL;
1256         }
1257 
1258         bpobj_close(&spa->spa_deferred_bpobj);
1259 
1260         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1261 
1262         /*
1263          * Close all vdevs.
1264          */
1265         if (spa->spa_root_vdev)
1266                 vdev_free(spa->spa_root_vdev);
1267         ASSERT(spa->spa_root_vdev == NULL);
1268 
1269         /*
1270          * Close the dsl pool.
1271          */
1272         if (spa->spa_dsl_pool) {
1273                 dsl_pool_close(spa->spa_dsl_pool);
1274                 spa->spa_dsl_pool = NULL;
1275                 spa->spa_meta_objset = NULL;
1276         }
1277 
1278         ddt_unload(spa);
1279 
1280 
1281         /*
1282          * Drop and purge level 2 cache
1283          */
1284         spa_l2cache_drop(spa);
1285 
1286         for (i = 0; i < spa->spa_spares.sav_count; i++)
1287                 vdev_free(spa->spa_spares.sav_vdevs[i]);
1288         if (spa->spa_spares.sav_vdevs) {
1289                 kmem_free(spa->spa_spares.sav_vdevs,
1290                     spa->spa_spares.sav_count * sizeof (void *));
1291                 spa->spa_spares.sav_vdevs = NULL;
1292         }
1293         if (spa->spa_spares.sav_config) {
1294                 nvlist_free(spa->spa_spares.sav_config);
1295                 spa->spa_spares.sav_config = NULL;
1296         }
1297         spa->spa_spares.sav_count = 0;
1298 
1299         for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
1300                 vdev_clear_stats(spa->spa_l2cache.sav_vdevs[i]);
1301                 vdev_free(spa->spa_l2cache.sav_vdevs[i]);
1302         }
1303         if (spa->spa_l2cache.sav_vdevs) {
1304                 kmem_free(spa->spa_l2cache.sav_vdevs,
1305                     spa->spa_l2cache.sav_count * sizeof (void *));
1306                 spa->spa_l2cache.sav_vdevs = NULL;
1307         }
1308         if (spa->spa_l2cache.sav_config) {
1309                 nvlist_free(spa->spa_l2cache.sav_config);
1310                 spa->spa_l2cache.sav_config = NULL;
1311         }
1312         spa->spa_l2cache.sav_count = 0;
1313 
1314         spa->spa_async_suspended = 0;
1315 
1316         if (spa->spa_comment != NULL) {
1317                 spa_strfree(spa->spa_comment);
1318                 spa->spa_comment = NULL;
1319         }
1320 
1321         spa_config_exit(spa, SCL_ALL, FTAG);
1322 }
1323 
1324 /*
1325  * Load (or re-load) the current list of vdevs describing the active spares for
1326  * this pool.  When this is called, we have some form of basic information in
1327  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
1328  * then re-generate a more complete list including status information.
1329  */
1330 static void
1331 spa_load_spares(spa_t *spa)
1332 {
1333         nvlist_t **spares;
1334         uint_t nspares;
1335         int i;
1336         vdev_t *vd, *tvd;
1337 
1338         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1339 
1340         /*
1341          * First, close and free any existing spare vdevs.
1342          */
1343         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1344                 vd = spa->spa_spares.sav_vdevs[i];
1345 
1346                 /* Undo the call to spa_activate() below */
1347                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1348                     B_FALSE)) != NULL && tvd->vdev_isspare)
1349                         spa_spare_remove(tvd);
1350                 vdev_close(vd);
1351                 vdev_free(vd);
1352         }
1353 
1354         if (spa->spa_spares.sav_vdevs)
1355                 kmem_free(spa->spa_spares.sav_vdevs,
1356                     spa->spa_spares.sav_count * sizeof (void *));
1357 
1358         if (spa->spa_spares.sav_config == NULL)
1359                 nspares = 0;
1360         else
1361                 VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1362                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1363 
1364         spa->spa_spares.sav_count = (int)nspares;
1365         spa->spa_spares.sav_vdevs = NULL;
1366 
1367         if (nspares == 0)
1368                 return;
1369 
1370         /*
1371          * Construct the array of vdevs, opening them to get status in the
1372          * process.   For each spare, there is potentially two different vdev_t
1373          * structures associated with it: one in the list of spares (used only
1374          * for basic validation purposes) and one in the active vdev
1375          * configuration (if it's spared in).  During this phase we open and
1376          * validate each vdev on the spare list.  If the vdev also exists in the
1377          * active configuration, then we also mark this vdev as an active spare.
1378          */
1379         spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
1380             KM_SLEEP);
1381         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1382                 VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
1383                     VDEV_ALLOC_SPARE) == 0);
1384                 ASSERT(vd != NULL);
1385 
1386                 spa->spa_spares.sav_vdevs[i] = vd;
1387 
1388                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1389                     B_FALSE)) != NULL) {
1390                         if (!tvd->vdev_isspare)
1391                                 spa_spare_add(tvd);
1392 
1393                         /*
1394                          * We only mark the spare active if we were successfully
1395                          * able to load the vdev.  Otherwise, importing a pool
1396                          * with a bad active spare would result in strange
1397                          * behavior, because multiple pool would think the spare
1398                          * is actively in use.
1399                          *
1400                          * There is a vulnerability here to an equally bizarre
1401                          * circumstance, where a dead active spare is later
1402                          * brought back to life (onlined or otherwise).  Given
1403                          * the rarity of this scenario, and the extra complexity
1404                          * it adds, we ignore the possibility.
1405                          */
1406                         if (!vdev_is_dead(tvd))
1407                                 spa_spare_activate(tvd);
1408                 }
1409 
1410                 vd->vdev_top = vd;
1411                 vd->vdev_aux = &spa->spa_spares;
1412 
1413                 if (vdev_open(vd) != 0)
1414                         continue;
1415 
1416                 if (vdev_validate_aux(vd) == 0)
1417                         spa_spare_add(vd);
1418         }
1419 
1420         /*
1421          * Recompute the stashed list of spares, with status information
1422          * this time.
1423          */
1424         VERIFY(nvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES,
1425             DATA_TYPE_NVLIST_ARRAY) == 0);
1426 
1427         spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
1428             KM_SLEEP);
1429         for (i = 0; i < spa->spa_spares.sav_count; i++)
1430                 spares[i] = vdev_config_generate(spa,
1431                     spa->spa_spares.sav_vdevs[i], B_TRUE, VDEV_CONFIG_SPARE);
1432         VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
1433             ZPOOL_CONFIG_SPARES, spares, spa->spa_spares.sav_count) == 0);
1434         for (i = 0; i < spa->spa_spares.sav_count; i++)
1435                 nvlist_free(spares[i]);
1436         kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
1437 }
1438 
1439 /*
1440  * Load (or re-load) the current list of vdevs describing the active l2cache for
1441  * this pool.  When this is called, we have some form of basic information in
1442  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
1443  * then re-generate a more complete list including status information.
1444  * Devices which are already active have their details maintained, and are
1445  * not re-opened.
1446  */
1447 static void
1448 spa_load_l2cache(spa_t *spa)
1449 {
1450         nvlist_t **l2cache;
1451         uint_t nl2cache;
1452         int i, j, oldnvdevs;
1453         uint64_t guid;
1454         vdev_t *vd, **oldvdevs, **newvdevs;
1455         spa_aux_vdev_t *sav = &spa->spa_l2cache;
1456 
1457         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1458 
1459         if (sav->sav_config != NULL) {
1460                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
1461                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1462                 newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
1463         } else {
1464                 nl2cache = 0;
1465                 newvdevs = NULL;
1466         }
1467 
1468         oldvdevs = sav->sav_vdevs;
1469         oldnvdevs = sav->sav_count;
1470         sav->sav_vdevs = NULL;
1471         sav->sav_count = 0;
1472 
1473         /*
1474          * Process new nvlist of vdevs.
1475          */
1476         for (i = 0; i < nl2cache; i++) {
1477                 VERIFY(nvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID,
1478                     &guid) == 0);
1479 
1480                 newvdevs[i] = NULL;
1481                 for (j = 0; j < oldnvdevs; j++) {
1482                         vd = oldvdevs[j];
1483                         if (vd != NULL && guid == vd->vdev_guid) {
1484                                 /*
1485                                  * Retain previous vdev for add/remove ops.
1486                                  */
1487                                 newvdevs[i] = vd;
1488                                 oldvdevs[j] = NULL;
1489                                 break;
1490                         }
1491                 }
1492 
1493                 if (newvdevs[i] == NULL) {
1494                         /*
1495                          * Create new vdev
1496                          */
1497                         VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
1498                             VDEV_ALLOC_L2CACHE) == 0);
1499                         ASSERT(vd != NULL);
1500                         newvdevs[i] = vd;
1501 
1502                         /*
1503                          * Commit this vdev as an l2cache device,
1504                          * even if it fails to open.
1505                          */
1506                         spa_l2cache_add(vd);
1507 
1508                         vd->vdev_top = vd;
1509                         vd->vdev_aux = sav;
1510 
1511                         spa_l2cache_activate(vd);
1512 
1513                         if (vdev_open(vd) != 0)
1514                                 continue;
1515 
1516                         (void) vdev_validate_aux(vd);
1517 
1518                         if (!vdev_is_dead(vd))
1519                                 l2arc_add_vdev(spa, vd);
1520                 }
1521         }
1522 
1523         /*
1524          * Purge vdevs that were dropped
1525          */
1526         for (i = 0; i < oldnvdevs; i++) {
1527                 uint64_t pool;
1528 
1529                 vd = oldvdevs[i];
1530                 if (vd != NULL) {
1531                         ASSERT(vd->vdev_isl2cache);
1532 
1533                         if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
1534                             pool != 0ULL && l2arc_vdev_present(vd))
1535                                 l2arc_remove_vdev(vd);
1536                         vdev_clear_stats(vd);
1537                         vdev_free(vd);
1538                 }
1539         }
1540 
1541         if (oldvdevs)
1542                 kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
1543 
1544         if (sav->sav_config == NULL)
1545                 goto out;
1546 
1547         sav->sav_vdevs = newvdevs;
1548         sav->sav_count = (int)nl2cache;
1549 
1550         /*
1551          * Recompute the stashed list of l2cache devices, with status
1552          * information this time.
1553          */
1554         VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
1555             DATA_TYPE_NVLIST_ARRAY) == 0);
1556 
1557         l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
1558         for (i = 0; i < sav->sav_count; i++)
1559                 l2cache[i] = vdev_config_generate(spa,
1560                     sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);
1561         VERIFY(nvlist_add_nvlist_array(sav->sav_config,
1562             ZPOOL_CONFIG_L2CACHE, l2cache, sav->sav_count) == 0);
1563 out:
1564         for (i = 0; i < sav->sav_count; i++)
1565                 nvlist_free(l2cache[i]);
1566         if (sav->sav_count)
1567                 kmem_free(l2cache, sav->sav_count * sizeof (void *));
1568 }
1569 
1570 static int
1571 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
1572 {
1573         dmu_buf_t *db;
1574         char *packed = NULL;
1575         size_t nvsize = 0;
1576         int error;
1577         *value = NULL;
1578 
1579         error = dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db);
1580         if (error != 0)
1581                 return (error);
1582 
1583         nvsize = *(uint64_t *)db->db_data;
1584         dmu_buf_rele(db, FTAG);
1585 
1586         packed = kmem_alloc(nvsize, KM_SLEEP);
1587         error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
1588             DMU_READ_PREFETCH);
1589         if (error == 0)
1590                 error = nvlist_unpack(packed, nvsize, value, 0);
1591         kmem_free(packed, nvsize);
1592 
1593         return (error);
1594 }
1595 
1596 /*
1597  * Checks to see if the given vdev could not be opened, in which case we post a
1598  * sysevent to notify the autoreplace code that the device has been removed.
1599  */
1600 static void
1601 spa_check_removed(vdev_t *vd)
1602 {
1603         for (int c = 0; c < vd->vdev_children; c++)
1604                 spa_check_removed(vd->vdev_child[c]);
1605 
1606         if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd) &&
1607             !vd->vdev_ishole) {
1608                 zfs_post_autoreplace(vd->vdev_spa, vd);
1609                 spa_event_notify(vd->vdev_spa, vd, ESC_ZFS_VDEV_CHECK);
1610         }
1611 }
1612 
1613 /*
1614  * Validate the current config against the MOS config
1615  */
1616 static boolean_t
1617 spa_config_valid(spa_t *spa, nvlist_t *config)
1618 {
1619         vdev_t *mrvd, *rvd = spa->spa_root_vdev;
1620         nvlist_t *nv;
1621 
1622         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nv) == 0);
1623 
1624         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1625         VERIFY(spa_config_parse(spa, &mrvd, nv, NULL, 0, VDEV_ALLOC_LOAD) == 0);
1626 
1627         ASSERT3U(rvd->vdev_children, ==, mrvd->vdev_children);
1628 
1629         /*
1630          * If we're doing a normal import, then build up any additional
1631          * diagnostic information about missing devices in this config.
1632          * We'll pass this up to the user for further processing.
1633          */
1634         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG)) {
1635                 nvlist_t **child, *nv;
1636                 uint64_t idx = 0;
1637 
1638                 child = kmem_alloc(rvd->vdev_children * sizeof (nvlist_t **),
1639                     KM_SLEEP);
1640                 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1641 
1642                 for (int c = 0; c < rvd->vdev_children; c++) {
1643                         vdev_t *tvd = rvd->vdev_child[c];
1644                         vdev_t *mtvd  = mrvd->vdev_child[c];
1645 
1646                         if (tvd->vdev_ops == &vdev_missing_ops &&
1647                             mtvd->vdev_ops != &vdev_missing_ops &&
1648                             mtvd->vdev_islog)
1649                                 child[idx++] = vdev_config_generate(spa, mtvd,
1650                                     B_FALSE, 0);
1651                 }
1652 
1653                 if (idx) {
1654                         VERIFY(nvlist_add_nvlist_array(nv,
1655                             ZPOOL_CONFIG_CHILDREN, child, idx) == 0);
1656                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
1657                             ZPOOL_CONFIG_MISSING_DEVICES, nv) == 0);
1658 
1659                         for (int i = 0; i < idx; i++)
1660                                 nvlist_free(child[i]);
1661                 }
1662                 nvlist_free(nv);
1663                 kmem_free(child, rvd->vdev_children * sizeof (char **));
1664         }
1665 
1666         /*
1667          * Compare the root vdev tree with the information we have
1668          * from the MOS config (mrvd). Check each top-level vdev
1669          * with the corresponding MOS config top-level (mtvd).
1670          */
1671         for (int c = 0; c < rvd->vdev_children; c++) {
1672                 vdev_t *tvd = rvd->vdev_child[c];
1673                 vdev_t *mtvd  = mrvd->vdev_child[c];
1674 
1675                 /*
1676                  * Resolve any "missing" vdevs in the current configuration.
1677                  * If we find that the MOS config has more accurate information
1678                  * about the top-level vdev then use that vdev instead.
1679                  */
1680                 if (tvd->vdev_ops == &vdev_missing_ops &&
1681                     mtvd->vdev_ops != &vdev_missing_ops) {
1682 
1683                         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG))
1684                                 continue;
1685 
1686                         /*
1687                          * Device specific actions.
1688                          */
1689                         if (mtvd->vdev_islog) {
1690                                 spa_set_log_state(spa, SPA_LOG_CLEAR);
1691                         } else {
1692                                 /*
1693                                  * XXX - once we have 'readonly' pool
1694                                  * support we should be able to handle
1695                                  * missing data devices by transitioning
1696                                  * the pool to readonly.
1697                                  */
1698                                 continue;
1699                         }
1700 
1701                         /*
1702                          * Swap the missing vdev with the data we were
1703                          * able to obtain from the MOS config.
1704                          */
1705                         vdev_remove_child(rvd, tvd);
1706                         vdev_remove_child(mrvd, mtvd);
1707 
1708                         vdev_add_child(rvd, mtvd);
1709                         vdev_add_child(mrvd, tvd);
1710 
1711                         spa_config_exit(spa, SCL_ALL, FTAG);
1712                         vdev_load(mtvd);
1713                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1714 
1715                         vdev_reopen(rvd);
1716                 } else if (mtvd->vdev_islog) {
1717                         /*
1718                          * Load the slog device's state from the MOS config
1719                          * since it's possible that the label does not
1720                          * contain the most up-to-date information.
1721                          */
1722                         vdev_load_log_state(tvd, mtvd);
1723                         vdev_reopen(tvd);
1724                 }
1725         }
1726         vdev_free(mrvd);
1727         spa_config_exit(spa, SCL_ALL, FTAG);
1728 
1729         /*
1730          * Ensure we were able to validate the config.
1731          */
1732         return (rvd->vdev_guid_sum == spa->spa_uberblock.ub_guid_sum);
1733 }
1734 
1735 /*
1736  * Check for missing log devices
1737  */
1738 static boolean_t
1739 spa_check_logs(spa_t *spa)
1740 {
1741         boolean_t rv = B_FALSE;
1742         dsl_pool_t *dp = spa_get_dsl(spa);
1743 
1744         switch (spa->spa_log_state) {
1745         case SPA_LOG_MISSING:
1746                 /* need to recheck in case slog has been restored */
1747         case SPA_LOG_UNKNOWN:
1748                 rv = (dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
1749                     zil_check_log_chain, NULL, DS_FIND_CHILDREN) != 0);
1750                 if (rv)
1751                         spa_set_log_state(spa, SPA_LOG_MISSING);
1752                 break;
1753         }
1754         return (rv);
1755 }
1756 
1757 static boolean_t
1758 spa_passivate_log(spa_t *spa)
1759 {
1760         vdev_t *rvd = spa->spa_root_vdev;
1761         boolean_t slog_found = B_FALSE;
1762 
1763         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1764 
1765         if (!spa_has_slogs(spa))
1766                 return (B_FALSE);
1767 
1768         for (int c = 0; c < rvd->vdev_children; c++) {
1769                 vdev_t *tvd = rvd->vdev_child[c];
1770                 metaslab_group_t *mg = tvd->vdev_mg;
1771 
1772                 if (tvd->vdev_islog) {
1773                         metaslab_group_passivate(mg);
1774                         slog_found = B_TRUE;
1775                 }
1776         }
1777 
1778         return (slog_found);
1779 }
1780 
1781 static void
1782 spa_activate_log(spa_t *spa)
1783 {
1784         vdev_t *rvd = spa->spa_root_vdev;
1785 
1786         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1787 
1788         for (int c = 0; c < rvd->vdev_children; c++) {
1789                 vdev_t *tvd = rvd->vdev_child[c];
1790                 metaslab_group_t *mg = tvd->vdev_mg;
1791 
1792                 if (tvd->vdev_islog)
1793                         metaslab_group_activate(mg);
1794         }
1795 }
1796 
1797 int
1798 spa_offline_log(spa_t *spa)
1799 {
1800         int error;
1801 
1802         error = dmu_objset_find(spa_name(spa), zil_vdev_offline,
1803             NULL, DS_FIND_CHILDREN);
1804         if (error == 0) {
1805                 /*
1806                  * We successfully offlined the log device, sync out the
1807                  * current txg so that the "stubby" block can be removed
1808                  * by zil_sync().
1809                  */
1810                 txg_wait_synced(spa->spa_dsl_pool, 0);
1811         }
1812         return (error);
1813 }
1814 
1815 static void
1816 spa_aux_check_removed(spa_aux_vdev_t *sav)
1817 {
1818         for (int i = 0; i < sav->sav_count; i++)
1819                 spa_check_removed(sav->sav_vdevs[i]);
1820 }
1821 
1822 void
1823 spa_claim_notify(zio_t *zio)
1824 {
1825         spa_t *spa = zio->io_spa;
1826 
1827         if (zio->io_error)
1828                 return;
1829 
1830         mutex_enter(&spa->spa_props_lock);       /* any mutex will do */
1831         if (spa->spa_claim_max_txg < zio->io_bp->blk_birth)
1832                 spa->spa_claim_max_txg = zio->io_bp->blk_birth;
1833         mutex_exit(&spa->spa_props_lock);
1834 }
1835 
1836 typedef struct spa_load_error {
1837         uint64_t        sle_meta_count;
1838         uint64_t        sle_data_count;
1839 } spa_load_error_t;
1840 
1841 static void
1842 spa_load_verify_done(zio_t *zio)
1843 {
1844         blkptr_t *bp = zio->io_bp;
1845         spa_load_error_t *sle = zio->io_private;
1846         dmu_object_type_t type = BP_GET_TYPE(bp);
1847         int error = zio->io_error;
1848         spa_t *spa = zio->io_spa;
1849 
1850         if (error) {
1851                 if ((BP_GET_LEVEL(bp) != 0 || DMU_OT_IS_METADATA(type)) &&
1852                     type != DMU_OT_INTENT_LOG)
1853                         atomic_inc_64(&sle->sle_meta_count);
1854                 else
1855                         atomic_inc_64(&sle->sle_data_count);
1856         }
1857         zio_data_buf_free(zio->io_data, zio->io_size);
1858 
1859         mutex_enter(&spa->spa_scrub_lock);
1860         spa->spa_scrub_inflight--;
1861         cv_broadcast(&spa->spa_scrub_io_cv);
1862         mutex_exit(&spa->spa_scrub_lock);
1863 }
1864 
1865 /*
1866  * Maximum number of concurrent scrub i/os to create while verifying
1867  * a pool while importing it.
1868  */
1869 int spa_load_verify_maxinflight = 10000;
1870 boolean_t spa_load_verify_metadata = B_TRUE;
1871 boolean_t spa_load_verify_data = B_TRUE;
1872 
1873 /*ARGSUSED*/
1874 static int
1875 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1876     const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
1877 {
1878         if (bp == NULL || BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp))
1879                 return (0);
1880         /*
1881          * Note: normally this routine will not be called if
1882          * spa_load_verify_metadata is not set.  However, it may be useful
1883          * to manually set the flag after the traversal has begun.
1884          */
1885         if (!spa_load_verify_metadata)
1886                 return (0);
1887         if (BP_GET_BUFC_TYPE(bp) == ARC_BUFC_DATA && !spa_load_verify_data)
1888                 return (0);
1889 
1890         zio_t *rio = arg;
1891         size_t size = BP_GET_PSIZE(bp);
1892         void *data = zio_data_buf_alloc(size);
1893 
1894         mutex_enter(&spa->spa_scrub_lock);
1895         while (spa->spa_scrub_inflight >= spa_load_verify_maxinflight)
1896                 cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock);
1897         spa->spa_scrub_inflight++;
1898         mutex_exit(&spa->spa_scrub_lock);
1899 
1900         zio_nowait(zio_read(rio, spa, bp, data, size,
1901             spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
1902             ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
1903             ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
1904         return (0);
1905 }
1906 
1907 static int
1908 spa_load_verify(spa_t *spa)
1909 {
1910         zio_t *rio;
1911         spa_load_error_t sle = { 0 };
1912         zpool_rewind_policy_t policy;
1913         boolean_t verify_ok = B_FALSE;
1914         int error = 0;
1915 
1916         zpool_get_rewind_policy(spa->spa_config, &policy);
1917 
1918         if (policy.zrp_request & ZPOOL_NEVER_REWIND)
1919                 return (0);
1920 
1921         rio = zio_root(spa, NULL, &sle,
1922             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1923 
1924         if (spa_load_verify_metadata) {
1925                 error = traverse_pool(spa, spa->spa_verify_min_txg,
1926                     TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA,
1927                     spa_load_verify_cb, rio);
1928         }
1929 
1930         (void) zio_wait(rio);
1931 
1932         spa->spa_load_meta_errors = sle.sle_meta_count;
1933         spa->spa_load_data_errors = sle.sle_data_count;
1934 
1935         if (!error && sle.sle_meta_count <= policy.zrp_maxmeta &&
1936             sle.sle_data_count <= policy.zrp_maxdata) {
1937                 int64_t loss = 0;
1938 
1939                 verify_ok = B_TRUE;
1940                 spa->spa_load_txg = spa->spa_uberblock.ub_txg;
1941                 spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
1942 
1943                 loss = spa->spa_last_ubsync_txg_ts - spa->spa_load_txg_ts;
1944                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1945                     ZPOOL_CONFIG_LOAD_TIME, spa->spa_load_txg_ts) == 0);
1946                 VERIFY(nvlist_add_int64(spa->spa_load_info,
1947                     ZPOOL_CONFIG_REWIND_TIME, loss) == 0);
1948                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1949                     ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count) == 0);
1950         } else {
1951                 spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
1952         }
1953 
1954         if (error) {
1955                 if (error != ENXIO && error != EIO)
1956                         error = SET_ERROR(EIO);
1957                 return (error);
1958         }
1959 
1960         return (verify_ok ? 0 : EIO);
1961 }
1962 
1963 /*
1964  * Find a value in the pool props object.
1965  */
1966 static void
1967 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
1968 {
1969         (void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
1970             zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
1971 }
1972 
1973 /*
1974  * Find a value in the pool directory object.
1975  */
1976 static int
1977 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val)
1978 {
1979         return (zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1980             name, sizeof (uint64_t), 1, val));
1981 }
1982 
1983 static int
1984 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
1985 {
1986         vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
1987         return (err);
1988 }
1989 
1990 /*
1991  * Fix up config after a partly-completed split.  This is done with the
1992  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
1993  * pool have that entry in their config, but only the splitting one contains
1994  * a list of all the guids of the vdevs that are being split off.
1995  *
1996  * This function determines what to do with that list: either rejoin
1997  * all the disks to the pool, or complete the splitting process.  To attempt
1998  * the rejoin, each disk that is offlined is marked online again, and
1999  * we do a reopen() call.  If the vdev label for every disk that was
2000  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
2001  * then we call vdev_split() on each disk, and complete the split.
2002  *
2003  * Otherwise we leave the config alone, with all the vdevs in place in
2004  * the original pool.
2005  */
2006 static void
2007 spa_try_repair(spa_t *spa, nvlist_t *config)
2008 {
2009         uint_t extracted;
2010         uint64_t *glist;
2011         uint_t i, gcount;
2012         nvlist_t *nvl;
2013         vdev_t **vd;
2014         boolean_t attempt_reopen;
2015 
2016         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
2017                 return;
2018 
2019         /* check that the config is complete */
2020         if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
2021             &glist, &gcount) != 0)
2022                 return;
2023 
2024         vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
2025 
2026         /* attempt to online all the vdevs & validate */
2027         attempt_reopen = B_TRUE;
2028         for (i = 0; i < gcount; i++) {
2029                 if (glist[i] == 0)      /* vdev is hole */
2030                         continue;
2031 
2032                 vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
2033                 if (vd[i] == NULL) {
2034                         /*
2035                          * Don't bother attempting to reopen the disks;
2036                          * just do the split.
2037                          */
2038                         attempt_reopen = B_FALSE;
2039                 } else {
2040                         /* attempt to re-online it */
2041                         vd[i]->vdev_offline = B_FALSE;
2042                 }
2043         }
2044 
2045         if (attempt_reopen) {
2046                 vdev_reopen(spa->spa_root_vdev);
2047 
2048                 /* check each device to see what state it's in */
2049                 for (extracted = 0, i = 0; i < gcount; i++) {
2050                         if (vd[i] != NULL &&
2051                             vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
2052                                 break;
2053                         ++extracted;
2054                 }
2055         }
2056 
2057         /*
2058          * If every disk has been moved to the new pool, or if we never
2059          * even attempted to look at them, then we split them off for
2060          * good.
2061          */
2062         if (!attempt_reopen || gcount == extracted) {
2063                 for (i = 0; i < gcount; i++)
2064                         if (vd[i] != NULL)
2065                                 vdev_split(vd[i]);
2066                 vdev_reopen(spa->spa_root_vdev);
2067         }
2068 
2069         kmem_free(vd, gcount * sizeof (vdev_t *));
2070 }
2071 
2072 static int
2073 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
2074     boolean_t mosconfig)
2075 {
2076         nvlist_t *config = spa->spa_config;
2077         char *ereport = FM_EREPORT_ZFS_POOL;
2078         char *comment;
2079         int error;
2080         uint64_t pool_guid;
2081         nvlist_t *nvl;
2082 
2083         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
2084                 return (SET_ERROR(EINVAL));
2085 
2086         ASSERT(spa->spa_comment == NULL);
2087         if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
2088                 spa->spa_comment = spa_strdup(comment);
2089 
2090         /*
2091          * Versioning wasn't explicitly added to the label until later, so if
2092          * it's not present treat it as the initial version.
2093          */
2094         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
2095             &spa->spa_ubsync.ub_version) != 0)
2096                 spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
2097 
2098         (void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
2099             &spa->spa_config_txg);
2100 
2101         if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
2102             spa_guid_exists(pool_guid, 0)) {
2103                 error = SET_ERROR(EEXIST);
2104         } else {
2105                 spa->spa_config_guid = pool_guid;
2106 
2107                 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT,
2108                     &nvl) == 0) {
2109                         VERIFY(nvlist_dup(nvl, &spa->spa_config_splitting,
2110                             KM_SLEEP) == 0);
2111                 }
2112 
2113                 nvlist_free(spa->spa_load_info);
2114                 spa->spa_load_info = fnvlist_alloc();
2115 
2116                 gethrestime(&spa->spa_loaded_ts);
2117                 error = spa_load_impl(spa, pool_guid, config, state, type,
2118                     mosconfig, &ereport);
2119         }
2120 
2121         /*
2122          * Don't count references from objsets that are already closed
2123          * and are making their way through the eviction process.
2124          */
2125         spa_evicting_os_wait(spa);
2126         spa->spa_minref = refcount_count(&spa->spa_refcount);
2127         if (error) {
2128                 if (error != EEXIST) {
2129                         spa->spa_loaded_ts.tv_sec = 0;
2130                         spa->spa_loaded_ts.tv_nsec = 0;
2131                 }
2132                 if (error != EBADF) {
2133                         zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
2134                 }
2135         }
2136         spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
2137         spa->spa_ena = 0;
2138 
2139         return (error);
2140 }
2141 
2142 /*
2143  * Load an existing storage pool, using the pool's builtin spa_config as a
2144  * source of configuration information.
2145  */
2146 static int
2147 spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config,
2148     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
2149     char **ereport)
2150 {
2151         int error = 0;
2152         nvlist_t *nvroot = NULL;
2153         nvlist_t *label;
2154         vdev_t *rvd;
2155         uberblock_t *ub = &spa->spa_uberblock;
2156         uint64_t children, config_cache_txg = spa->spa_config_txg;
2157         int orig_mode = spa->spa_mode;
2158         int parse;
2159         uint64_t obj;
2160         boolean_t missing_feat_write = B_FALSE;
2161 
2162         /*
2163          * If this is an untrusted config, access the pool in read-only mode.
2164          * This prevents things like resilvering recently removed devices.
2165          */
2166         if (!mosconfig)
2167                 spa->spa_mode = FREAD;
2168 
2169         ASSERT(MUTEX_HELD(&spa_namespace_lock));
2170 
2171         spa->spa_load_state = state;
2172 
2173         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot))
2174                 return (SET_ERROR(EINVAL));
2175 
2176         parse = (type == SPA_IMPORT_EXISTING ?
2177             VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
2178 
2179         /*
2180          * Create "The Godfather" zio to hold all async IOs
2181          */
2182         spa->spa_async_zio_root = kmem_alloc(max_ncpus * sizeof (void *),
2183             KM_SLEEP);
2184         for (int i = 0; i < max_ncpus; i++) {
2185                 spa->spa_async_zio_root[i] = zio_root(spa, NULL, NULL,
2186                     ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
2187                     ZIO_FLAG_GODFATHER);
2188         }
2189 
2190         /*
2191          * Parse the configuration into a vdev tree.  We explicitly set the
2192          * value that will be returned by spa_version() since parsing the
2193          * configuration requires knowing the version number.
2194          */
2195         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2196         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, parse);
2197         spa_config_exit(spa, SCL_ALL, FTAG);
2198 
2199         if (error != 0)
2200                 return (error);
2201 
2202         ASSERT(spa->spa_root_vdev == rvd);
2203         ASSERT3U(spa->spa_min_ashift, >=, SPA_MINBLOCKSHIFT);
2204         ASSERT3U(spa->spa_max_ashift, <=, SPA_MAXBLOCKSHIFT);
2205 
2206         if (type != SPA_IMPORT_ASSEMBLE) {
2207                 ASSERT(spa_guid(spa) == pool_guid);
2208         }
2209 
2210         /*
2211          * Try to open all vdevs, loading each label in the process.
2212          */
2213         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2214         error = vdev_open(rvd);
2215         spa_config_exit(spa, SCL_ALL, FTAG);
2216         if (error != 0)
2217                 return (error);
2218 
2219         /*
2220          * We need to validate the vdev labels against the configuration that
2221          * we have in hand, which is dependent on the setting of mosconfig. If
2222          * mosconfig is true then we're validating the vdev labels based on
2223          * that config.  Otherwise, we're validating against the cached config
2224          * (zpool.cache) that was read when we loaded the zfs module, and then
2225          * later we will recursively call spa_load() and validate against
2226          * the vdev config.
2227          *
2228          * If we're assembling a new pool that's been split off from an
2229          * existing pool, the labels haven't yet been updated so we skip
2230          * validation for now.
2231          */
2232         if (type != SPA_IMPORT_ASSEMBLE) {
2233                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2234                 error = vdev_validate(rvd, mosconfig);
2235                 spa_config_exit(spa, SCL_ALL, FTAG);
2236 
2237                 if (error != 0)
2238                         return (error);
2239 
2240                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2241                         return (SET_ERROR(ENXIO));
2242         }
2243 
2244         /*
2245          * Find the best uberblock.
2246          */
2247         vdev_uberblock_load(rvd, ub, &label);
2248 
2249         /*
2250          * If we weren't able to find a single valid uberblock, return failure.
2251          */
2252         if (ub->ub_txg == 0) {
2253                 nvlist_free(label);
2254                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
2255         }
2256 
2257         /*
2258          * If the pool has an unsupported version we can't open it.
2259          */
2260         if (!SPA_VERSION_IS_SUPPORTED(ub->ub_version)) {
2261                 nvlist_free(label);
2262                 return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
2263         }
2264 
2265         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2266                 nvlist_t *features;
2267 
2268                 /*
2269                  * If we weren't able to find what's necessary for reading the
2270                  * MOS in the label, return failure.
2271                  */
2272                 if (label == NULL || nvlist_lookup_nvlist(label,
2273                     ZPOOL_CONFIG_FEATURES_FOR_READ, &features) != 0) {
2274                         nvlist_free(label);
2275                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2276                             ENXIO));
2277                 }
2278 
2279                 /*
2280                  * Update our in-core representation with the definitive values
2281                  * from the label.
2282                  */
2283                 nvlist_free(spa->spa_label_features);
2284                 VERIFY(nvlist_dup(features, &spa->spa_label_features, 0) == 0);
2285         }
2286 
2287         nvlist_free(label);
2288 
2289         /*
2290          * Look through entries in the label nvlist's features_for_read. If
2291          * there is a feature listed there which we don't understand then we
2292          * cannot open a pool.
2293          */
2294         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2295                 nvlist_t *unsup_feat;
2296 
2297                 VERIFY(nvlist_alloc(&unsup_feat, NV_UNIQUE_NAME, KM_SLEEP) ==
2298                     0);
2299 
2300                 for (nvpair_t *nvp = nvlist_next_nvpair(spa->spa_label_features,
2301                     NULL); nvp != NULL;
2302                     nvp = nvlist_next_nvpair(spa->spa_label_features, nvp)) {
2303                         if (!zfeature_is_supported(nvpair_name(nvp))) {
2304                                 VERIFY(nvlist_add_string(unsup_feat,
2305                                     nvpair_name(nvp), "") == 0);
2306                         }
2307                 }
2308 
2309                 if (!nvlist_empty(unsup_feat)) {
2310                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
2311                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat) == 0);
2312                         nvlist_free(unsup_feat);
2313                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2314                             ENOTSUP));
2315                 }
2316 
2317                 nvlist_free(unsup_feat);
2318         }
2319 
2320         /*
2321          * If the vdev guid sum doesn't match the uberblock, we have an
2322          * incomplete configuration.  We first check to see if the pool
2323          * is aware of the complete config (i.e ZPOOL_CONFIG_VDEV_CHILDREN).
2324          * If it is, defer the vdev_guid_sum check till later so we
2325          * can handle missing vdevs.
2326          */
2327         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN,
2328             &children) != 0 && mosconfig && type != SPA_IMPORT_ASSEMBLE &&
2329             rvd->vdev_guid_sum != ub->ub_guid_sum)
2330                 return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
2331 
2332         if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
2333                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2334                 spa_try_repair(spa, config);
2335                 spa_config_exit(spa, SCL_ALL, FTAG);
2336                 nvlist_free(spa->spa_config_splitting);
2337                 spa->spa_config_splitting = NULL;
2338         }
2339 
2340         /*
2341          * Initialize internal SPA structures.
2342          */
2343         spa->spa_state = POOL_STATE_ACTIVE;
2344         spa->spa_ubsync = spa->spa_uberblock;
2345         spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
2346             TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
2347         spa->spa_first_txg = spa->spa_last_ubsync_txg ?
2348             spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
2349         spa->spa_claim_max_txg = spa->spa_first_txg;
2350         spa->spa_prev_software_version = ub->ub_software_version;
2351 
2352         error = dsl_pool_init(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
2353         if (error)
2354                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2355         spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
2356 
2357         if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object) != 0)
2358                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2359 
2360         if (spa_version(spa) >= SPA_VERSION_FEATURES) {
2361                 boolean_t missing_feat_read = B_FALSE;
2362                 nvlist_t *unsup_feat, *enabled_feat;
2363 
2364                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_READ,
2365                     &spa->spa_feat_for_read_obj) != 0) {
2366                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2367                 }
2368 
2369                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_WRITE,
2370                     &spa->spa_feat_for_write_obj) != 0) {
2371                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2372                 }
2373 
2374                 if (spa_dir_prop(spa, DMU_POOL_FEATURE_DESCRIPTIONS,
2375                     &spa->spa_feat_desc_obj) != 0) {
2376                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2377                 }
2378 
2379                 enabled_feat = fnvlist_alloc();
2380                 unsup_feat = fnvlist_alloc();
2381 
2382                 if (!spa_features_check(spa, B_FALSE,
2383                     unsup_feat, enabled_feat))
2384                         missing_feat_read = B_TRUE;
2385 
2386                 if (spa_writeable(spa) || state == SPA_LOAD_TRYIMPORT) {
2387                         if (!spa_features_check(spa, B_TRUE,
2388                             unsup_feat, enabled_feat)) {
2389                                 missing_feat_write = B_TRUE;
2390                         }
2391                 }
2392 
2393                 fnvlist_add_nvlist(spa->spa_load_info,
2394                     ZPOOL_CONFIG_ENABLED_FEAT, enabled_feat);
2395 
2396                 if (!nvlist_empty(unsup_feat)) {
2397                         fnvlist_add_nvlist(spa->spa_load_info,
2398                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
2399                 }
2400 
2401                 fnvlist_free(enabled_feat);
2402                 fnvlist_free(unsup_feat);
2403 
2404                 if (!missing_feat_read) {
2405                         fnvlist_add_boolean(spa->spa_load_info,
2406                             ZPOOL_CONFIG_CAN_RDONLY);
2407                 }
2408 
2409                 /*
2410                  * If the state is SPA_LOAD_TRYIMPORT, our objective is
2411                  * twofold: to determine whether the pool is available for
2412                  * import in read-write mode and (if it is not) whether the
2413                  * pool is available for import in read-only mode. If the pool
2414                  * is available for import in read-write mode, it is displayed
2415                  * as available in userland; if it is not available for import
2416                  * in read-only mode, it is displayed as unavailable in
2417                  * userland. If the pool is available for import in read-only
2418                  * mode but not read-write mode, it is displayed as unavailable
2419                  * in userland with a special note that the pool is actually
2420                  * available for open in read-only mode.
2421                  *
2422                  * As a result, if the state is SPA_LOAD_TRYIMPORT and we are
2423                  * missing a feature for write, we must first determine whether
2424                  * the pool can be opened read-only before returning to
2425                  * userland in order to know whether to display the
2426                  * abovementioned note.
2427                  */
2428                 if (missing_feat_read || (missing_feat_write &&
2429                     spa_writeable(spa))) {
2430                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2431                             ENOTSUP));
2432                 }
2433 
2434                 /*
2435                  * Load refcounts for ZFS features from disk into an in-memory
2436                  * cache during SPA initialization.
2437                  */
2438                 for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
2439                         uint64_t refcount;
2440 
2441                         error = feature_get_refcount_from_disk(spa,
2442                             &spa_feature_table[i], &refcount);
2443                         if (error == 0) {
2444                                 spa->spa_feat_refcount_cache[i] = refcount;
2445                         } else if (error == ENOTSUP) {
2446                                 spa->spa_feat_refcount_cache[i] =
2447                                     SPA_FEATURE_DISABLED;
2448                         } else {
2449                                 return (spa_vdev_err(rvd,
2450                                     VDEV_AUX_CORRUPT_DATA, EIO));
2451                         }
2452                 }
2453         }
2454 
2455         if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
2456                 if (spa_dir_prop(spa, DMU_POOL_FEATURE_ENABLED_TXG,
2457                     &spa->spa_feat_enabled_txg_obj) != 0)
2458                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2459         }
2460 
2461         spa->spa_is_initializing = B_TRUE;
2462         error = dsl_pool_open(spa->spa_dsl_pool);
2463         spa->spa_is_initializing = B_FALSE;
2464         if (error != 0)
2465                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2466 
2467         if (!mosconfig) {
2468                 uint64_t hostid;
2469                 nvlist_t *policy = NULL, *nvconfig;
2470 
2471                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2472                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2473 
2474                 if (!spa_is_root(spa) && nvlist_lookup_uint64(nvconfig,
2475                     ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
2476                         char *hostname;
2477                         unsigned long myhostid = 0;
2478 
2479                         VERIFY(nvlist_lookup_string(nvconfig,
2480                             ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
2481 
2482 #ifdef  _KERNEL
2483                         myhostid = zone_get_hostid(NULL);
2484 #else   /* _KERNEL */
2485                         /*
2486                          * We're emulating the system's hostid in userland, so
2487                          * we can't use zone_get_hostid().
2488                          */
2489                         (void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
2490 #endif  /* _KERNEL */
2491                         if (hostid != 0 && myhostid != 0 &&
2492                             hostid != myhostid) {
2493                                 nvlist_free(nvconfig);
2494                                 cmn_err(CE_WARN, "pool '%s' could not be "
2495                                     "loaded as it was last accessed by "
2496                                     "another system (host: %s hostid: 0x%lx). "
2497                                     "See: http://illumos.org/msg/ZFS-8000-EY",
2498                                     spa_name(spa), hostname,
2499                                     (unsigned long)hostid);
2500                                 return (SET_ERROR(EBADF));
2501                         }
2502                 }
2503                 if (nvlist_lookup_nvlist(spa->spa_config,
2504                     ZPOOL_REWIND_POLICY, &policy) == 0)
2505                         VERIFY(nvlist_add_nvlist(nvconfig,
2506                             ZPOOL_REWIND_POLICY, policy) == 0);
2507 
2508                 spa_config_set(spa, nvconfig);
2509                 spa_unload(spa);
2510                 spa_deactivate(spa);
2511                 spa_activate(spa, orig_mode);
2512 
2513                 return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
2514         }
2515 
2516         /* Grab the secret checksum salt from the MOS. */
2517         error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
2518             DMU_POOL_CHECKSUM_SALT, 1,
2519             sizeof (spa->spa_cksum_salt.zcs_bytes),
2520             spa->spa_cksum_salt.zcs_bytes);
2521         if (error == ENOENT) {
2522                 /* Generate a new salt for subsequent use */
2523                 (void) random_get_pseudo_bytes(spa->spa_cksum_salt.zcs_bytes,
2524                     sizeof (spa->spa_cksum_salt.zcs_bytes));
2525         } else if (error != 0) {
2526                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2527         }
2528 
2529         if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj) != 0)
2530                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2531         error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
2532         if (error != 0)
2533                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2534 
2535         /*
2536          * Load the bit that tells us to use the new accounting function
2537          * (raid-z deflation).  If we have an older pool, this will not
2538          * be present.
2539          */
2540         error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate);
2541         if (error != 0 && error != ENOENT)
2542                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2543 
2544         error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
2545             &spa->spa_creation_version);
2546         if (error != 0 && error != ENOENT)
2547                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2548 
2549         /*
2550          * Load the persistent error log.  If we have an older pool, this will
2551          * not be present.
2552          */
2553         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last);
2554         if (error != 0 && error != ENOENT)
2555                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2556 
2557         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
2558             &spa->spa_errlog_scrub);
2559         if (error != 0 && error != ENOENT)
2560                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2561 
2562         /*
2563          * Load the history object.  If we have an older pool, this
2564          * will not be present.
2565          */
2566         error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history);
2567         if (error != 0 && error != ENOENT)
2568                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2569 
2570         /*
2571          * If we're assembling the pool from the split-off vdevs of
2572          * an existing pool, we don't want to attach the spares & cache
2573          * devices.
2574          */
2575 
2576         /*
2577          * Load any hot spares for this pool.
2578          */
2579         error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object);
2580         if (error != 0 && error != ENOENT)
2581                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2582         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2583                 ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
2584                 if (load_nvlist(spa, spa->spa_spares.sav_object,
2585                     &spa->spa_spares.sav_config) != 0)
2586                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2587 
2588                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2589                 spa_load_spares(spa);
2590                 spa_config_exit(spa, SCL_ALL, FTAG);
2591         } else if (error == 0) {
2592                 spa->spa_spares.sav_sync = B_TRUE;
2593         }
2594 
2595         /*
2596          * Load any level 2 ARC devices for this pool.
2597          */
2598         error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
2599             &spa->spa_l2cache.sav_object);
2600         if (error != 0 && error != ENOENT)
2601                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2602         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2603                 ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
2604                 if (load_nvlist(spa, spa->spa_l2cache.sav_object,
2605                     &spa->spa_l2cache.sav_config) != 0)
2606                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2607 
2608                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2609                 spa_load_l2cache(spa);
2610                 spa_config_exit(spa, SCL_ALL, FTAG);
2611         } else if (error == 0) {
2612                 spa->spa_l2cache.sav_sync = B_TRUE;
2613         }
2614 
2615         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2616 
2617         error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object);
2618         if (error && error != ENOENT)
2619                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2620 
2621         if (error == 0) {
2622                 uint64_t autoreplace;
2623 
2624                 spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
2625                 spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
2626                 spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
2627                 spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
2628                 spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
2629                 spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
2630                     &spa->spa_dedup_ditto);
2631 
2632                 spa->spa_autoreplace = (autoreplace != 0);
2633         }
2634 
2635         /*
2636          * If the 'autoreplace' property is set, then post a resource notifying
2637          * the ZFS DE that it should not issue any faults for unopenable
2638          * devices.  We also iterate over the vdevs, and post a sysevent for any
2639          * unopenable vdevs so that the normal autoreplace handler can take
2640          * over.
2641          */
2642         if (spa->spa_autoreplace && state != SPA_LOAD_TRYIMPORT) {
2643                 spa_check_removed(spa->spa_root_vdev);
2644                 /*
2645                  * For the import case, this is done in spa_import(), because
2646                  * at this point we're using the spare definitions from
2647                  * the MOS config, not necessarily from the userland config.
2648                  */
2649                 if (state != SPA_LOAD_IMPORT) {
2650                         spa_aux_check_removed(&spa->spa_spares);
2651                         spa_aux_check_removed(&spa->spa_l2cache);
2652                 }
2653         }
2654 
2655         /*
2656          * Load the vdev state for all toplevel vdevs.
2657          */
2658         vdev_load(rvd);
2659 
2660         /*
2661          * Propagate the leaf DTLs we just loaded all the way up the tree.
2662          */
2663         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2664         vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
2665         spa_config_exit(spa, SCL_ALL, FTAG);
2666 
2667         /*
2668          * Load the DDTs (dedup tables).
2669          */
2670         error = ddt_load(spa);
2671         if (error != 0)
2672                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2673 
2674         spa_update_dspace(spa);
2675 
2676         /*
2677          * Validate the config, using the MOS config to fill in any
2678          * information which might be missing.  If we fail to validate
2679          * the config then declare the pool unfit for use. If we're
2680          * assembling a pool from a split, the log is not transferred
2681          * over.
2682          */
2683         if (type != SPA_IMPORT_ASSEMBLE) {
2684                 nvlist_t *nvconfig;
2685 
2686                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2687                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2688 
2689                 if (!spa_config_valid(spa, nvconfig)) {
2690                         nvlist_free(nvconfig);
2691                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
2692                             ENXIO));
2693                 }
2694                 nvlist_free(nvconfig);
2695 
2696                 /*
2697                  * Now that we've validated the config, check the state of the
2698                  * root vdev.  If it can't be opened, it indicates one or
2699                  * more toplevel vdevs are faulted.
2700                  */
2701                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2702                         return (SET_ERROR(ENXIO));
2703 
2704                 if (spa_writeable(spa) && spa_check_logs(spa)) {
2705                         *ereport = FM_EREPORT_ZFS_LOG_REPLAY;
2706                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG, ENXIO));
2707                 }
2708         }
2709 
2710         if (missing_feat_write) {
2711                 ASSERT(state == SPA_LOAD_TRYIMPORT);
2712 
2713                 /*
2714                  * At this point, we know that we can open the pool in
2715                  * read-only mode but not read-write mode. We now have enough
2716                  * information and can return to userland.
2717                  */
2718                 return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT, ENOTSUP));
2719         }
2720 
2721         /*
2722          * We've successfully opened the pool, verify that we're ready
2723          * to start pushing transactions.
2724          */
2725         if (state != SPA_LOAD_TRYIMPORT) {
2726                 if (error = spa_load_verify(spa))
2727                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2728                             error));
2729         }
2730 
2731         if (spa_writeable(spa) && (state == SPA_LOAD_RECOVER ||
2732             spa->spa_load_max_txg == UINT64_MAX)) {
2733                 dmu_tx_t *tx;
2734                 int need_update = B_FALSE;
2735                 dsl_pool_t *dp = spa_get_dsl(spa);
2736 
2737                 ASSERT(state != SPA_LOAD_TRYIMPORT);
2738 
2739                 /*
2740                  * Claim log blocks that haven't been committed yet.
2741                  * This must all happen in a single txg.
2742                  * Note: spa_claim_max_txg is updated by spa_claim_notify(),
2743                  * invoked from zil_claim_log_block()'s i/o done callback.
2744                  * Price of rollback is that we abandon the log.
2745                  */
2746                 spa->spa_claiming = B_TRUE;
2747 
2748                 tx = dmu_tx_create_assigned(dp, spa_first_txg(spa));
2749                 (void) dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
2750                     zil_claim, tx, DS_FIND_CHILDREN);
2751                 dmu_tx_commit(tx);
2752 
2753                 spa->spa_claiming = B_FALSE;
2754 
2755                 spa_set_log_state(spa, SPA_LOG_GOOD);
2756                 spa->spa_sync_on = B_TRUE;
2757                 txg_sync_start(spa->spa_dsl_pool);
2758 
2759                 /*
2760                  * Wait for all claims to sync.  We sync up to the highest
2761                  * claimed log block birth time so that claimed log blocks
2762                  * don't appear to be from the future.  spa_claim_max_txg
2763                  * will have been set for us by either zil_check_log_chain()
2764                  * (invoked from spa_check_logs()) or zil_claim() above.
2765                  */
2766                 txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
2767 
2768                 /*
2769                  * If the config cache is stale, or we have uninitialized
2770                  * metaslabs (see spa_vdev_add()), then update the config.
2771                  *
2772                  * If this is a verbatim import, trust the current
2773                  * in-core spa_config and update the disk labels.
2774                  */
2775                 if (config_cache_txg != spa->spa_config_txg ||
2776                     state == SPA_LOAD_IMPORT ||
2777                     state == SPA_LOAD_RECOVER ||
2778                     (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
2779                         need_update = B_TRUE;
2780 
2781                 for (int c = 0; c < rvd->vdev_children; c++)
2782                         if (rvd->vdev_child[c]->vdev_ms_array == 0)
2783                                 need_update = B_TRUE;
2784 
2785                 /*
2786                  * Update the config cache asychronously in case we're the
2787                  * root pool, in which case the config cache isn't writable yet.
2788                  */
2789                 if (need_update)
2790                         spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2791 
2792                 /*
2793                  * Check all DTLs to see if anything needs resilvering.
2794                  */
2795                 if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
2796                     vdev_resilver_needed(rvd, NULL, NULL))
2797                         spa_async_request(spa, SPA_ASYNC_RESILVER);
2798 
2799                 /*
2800                  * Log the fact that we booted up (so that we can detect if
2801                  * we rebooted in the middle of an operation).
2802                  */
2803                 spa_history_log_version(spa, "open");
2804 
2805                 /*
2806                  * Delete any inconsistent datasets.
2807                  */
2808                 (void) dmu_objset_find(spa_name(spa),
2809                     dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
2810 
2811                 /*
2812                  * Clean up any stale temporary dataset userrefs.
2813                  */
2814                 dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
2815         }
2816 
2817         return (0);
2818 }
2819 
2820 static int
2821 spa_load_retry(spa_t *spa, spa_load_state_t state, int mosconfig)
2822 {
2823         int mode = spa->spa_mode;
2824 
2825         spa_unload(spa);
2826         spa_deactivate(spa);
2827 
2828         spa->spa_load_max_txg = spa->spa_uberblock.ub_txg - 1;
2829 
2830         spa_activate(spa, mode);
2831         spa_async_suspend(spa);
2832 
2833         return (spa_load(spa, state, SPA_IMPORT_EXISTING, mosconfig));
2834 }
2835 
2836 /*
2837  * If spa_load() fails this function will try loading prior txg's. If
2838  * 'state' is SPA_LOAD_RECOVER and one of these loads succeeds the pool
2839  * will be rewound to that txg. If 'state' is not SPA_LOAD_RECOVER this
2840  * function will not rewind the pool and will return the same error as
2841  * spa_load().
2842  */
2843 static int
2844 spa_load_best(spa_t *spa, spa_load_state_t state, int mosconfig,
2845     uint64_t max_request, int rewind_flags)
2846 {
2847         nvlist_t *loadinfo = NULL;
2848         nvlist_t *config = NULL;
2849         int load_error, rewind_error;
2850         uint64_t safe_rewind_txg;
2851         uint64_t min_txg;
2852 
2853         if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
2854                 spa->spa_load_max_txg = spa->spa_load_txg;
2855                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2856         } else {
2857                 spa->spa_load_max_txg = max_request;
2858                 if (max_request != UINT64_MAX)
2859                         spa->spa_extreme_rewind = B_TRUE;
2860         }
2861 
2862         load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING,
2863             mosconfig);
2864         if (load_error == 0)
2865                 return (0);
2866 
2867         if (spa->spa_root_vdev != NULL)
2868                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2869 
2870         spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
2871         spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
2872 
2873         if (rewind_flags & ZPOOL_NEVER_REWIND) {
2874                 nvlist_free(config);
2875                 return (load_error);
2876         }
2877 
2878         if (state == SPA_LOAD_RECOVER) {
2879                 /* Price of rolling back is discarding txgs, including log */
2880                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2881         } else {
2882                 /*
2883                  * If we aren't rolling back save the load info from our first
2884                  * import attempt so that we can restore it after attempting
2885                  * to rewind.
2886                  */
2887                 loadinfo = spa->spa_load_info;
2888                 spa->spa_load_info = fnvlist_alloc();
2889         }
2890 
2891         spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
2892         safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
2893         min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
2894             TXG_INITIAL : safe_rewind_txg;
2895 
2896         /*
2897          * Continue as long as we're finding errors, we're still within
2898          * the acceptable rewind range, and we're still finding uberblocks
2899          */
2900         while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
2901             spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
2902                 if (spa->spa_load_max_txg < safe_rewind_txg)
2903                         spa->spa_extreme_rewind = B_TRUE;
2904                 rewind_error = spa_load_retry(spa, state, mosconfig);
2905         }
2906 
2907         spa->spa_extreme_rewind = B_FALSE;
2908         spa->spa_load_max_txg = UINT64_MAX;
2909 
2910         if (config && (rewind_error || state != SPA_LOAD_RECOVER))
2911                 spa_config_set(spa, config);
2912 
2913         if (state == SPA_LOAD_RECOVER) {
2914                 ASSERT3P(loadinfo, ==, NULL);
2915                 return (rewind_error);
2916         } else {
2917                 /* Store the rewind info as part of the initial load info */
2918                 fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
2919                     spa->spa_load_info);
2920 
2921                 /* Restore the initial load info */
2922                 fnvlist_free(spa->spa_load_info);
2923                 spa->spa_load_info = loadinfo;
2924 
2925                 return (load_error);
2926         }
2927 }
2928 
2929 /*
2930  * Pool Open/Import
2931  *
2932  * The import case is identical to an open except that the configuration is sent
2933  * down from userland, instead of grabbed from the configuration cache.  For the
2934  * case of an open, the pool configuration will exist in the
2935  * POOL_STATE_UNINITIALIZED state.
2936  *
2937  * The stats information (gen/count/ustats) is used to gather vdev statistics at
2938  * the same time open the pool, without having to keep around the spa_t in some
2939  * ambiguous state.
2940  */
2941 static int
2942 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
2943     nvlist_t **config)
2944 {
2945         spa_t *spa;
2946         spa_load_state_t state = SPA_LOAD_OPEN;
2947         int error;
2948         int locked = B_FALSE;
2949 
2950         *spapp = NULL;
2951 
2952         /*
2953          * As disgusting as this is, we need to support recursive calls to this
2954          * function because dsl_dir_open() is called during spa_load(), and ends
2955          * up calling spa_open() again.  The real fix is to figure out how to
2956          * avoid dsl_dir_open() calling this in the first place.
2957          */
2958         if (mutex_owner(&spa_namespace_lock) != curthread) {
2959                 mutex_enter(&spa_namespace_lock);
2960                 locked = B_TRUE;
2961         }
2962 
2963         if ((spa = spa_lookup(pool)) == NULL) {
2964                 if (locked)
2965                         mutex_exit(&spa_namespace_lock);
2966                 return (SET_ERROR(ENOENT));
2967         }
2968 
2969         if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
2970                 zpool_rewind_policy_t policy;
2971 
2972                 zpool_get_rewind_policy(nvpolicy ? nvpolicy : spa->spa_config,
2973                     &policy);
2974                 if (policy.zrp_request & ZPOOL_DO_REWIND)
2975                         state = SPA_LOAD_RECOVER;
2976 
2977                 spa_activate(spa, spa_mode_global);
2978 
2979                 if (state != SPA_LOAD_RECOVER)
2980                         spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
2981 
2982                 error = spa_load_best(spa, state, B_FALSE, policy.zrp_txg,
2983                     policy.zrp_request);
2984 
2985                 if (error == EBADF) {
2986                         /*
2987                          * If vdev_validate() returns failure (indicated by
2988                          * EBADF), it indicates that one of the vdevs indicates
2989                          * that the pool has been exported or destroyed.  If
2990                          * this is the case, the config cache is out of sync and
2991                          * we should remove the pool from the namespace.
2992                          */
2993                         spa_unload(spa);
2994                         spa_deactivate(spa);
2995                         spa_config_sync(spa, B_TRUE, B_TRUE);
2996                         spa_remove(spa);
2997                         if (locked)
2998                                 mutex_exit(&spa_namespace_lock);
2999                         return (SET_ERROR(ENOENT));
3000                 }
3001 
3002                 if (error) {
3003                         /*
3004                          * We can't open the pool, but we still have useful
3005                          * information: the state of each vdev after the
3006                          * attempted vdev_open().  Return this to the user.
3007                          */
3008                         if (config != NULL && spa->spa_config) {
3009                                 VERIFY(nvlist_dup(spa->spa_config, config,
3010                                     KM_SLEEP) == 0);
3011                                 VERIFY(nvlist_add_nvlist(*config,
3012                                     ZPOOL_CONFIG_LOAD_INFO,
3013                                     spa->spa_load_info) == 0);
3014                         }
3015                         spa_unload(spa);
3016                         spa_deactivate(spa);
3017                         spa->spa_last_open_failed = error;
3018                         if (locked)
3019                                 mutex_exit(&spa_namespace_lock);
3020                         *spapp = NULL;
3021                         return (error);
3022                 }
3023         }
3024 
3025         spa_open_ref(spa, tag);
3026 
3027         if (config != NULL)
3028                 *config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
3029 
3030         /*
3031          * If we've recovered the pool, pass back any information we
3032          * gathered while doing the load.
3033          */
3034         if (state == SPA_LOAD_RECOVER) {
3035                 VERIFY(nvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
3036                     spa->spa_load_info) == 0);
3037         }
3038 
3039         if (locked) {
3040                 spa->spa_last_open_failed = 0;
3041                 spa->spa_last_ubsync_txg = 0;
3042                 spa->spa_load_txg = 0;
3043                 mutex_exit(&spa_namespace_lock);
3044         }
3045 
3046         *spapp = spa;
3047 
3048         return (0);
3049 }
3050 
3051 int
3052 spa_open_rewind(const char *name, spa_t **spapp, void *tag, nvlist_t *policy,
3053     nvlist_t **config)
3054 {
3055         return (spa_open_common(name, spapp, tag, policy, config));
3056 }
3057 
3058 int
3059 spa_open(const char *name, spa_t **spapp, void *tag)
3060 {
3061         return (spa_open_common(name, spapp, tag, NULL, NULL));
3062 }
3063 
3064 /*
3065  * Lookup the given spa_t, incrementing the inject count in the process,
3066  * preventing it from being exported or destroyed.
3067  */
3068 spa_t *
3069 spa_inject_addref(char *name)
3070 {
3071         spa_t *spa;
3072 
3073         mutex_enter(&spa_namespace_lock);
3074         if ((spa = spa_lookup(name)) == NULL) {
3075                 mutex_exit(&spa_namespace_lock);
3076                 return (NULL);
3077         }
3078         spa->spa_inject_ref++;
3079         mutex_exit(&spa_namespace_lock);
3080 
3081         return (spa);
3082 }
3083 
3084 void
3085 spa_inject_delref(spa_t *spa)
3086 {
3087         mutex_enter(&spa_namespace_lock);
3088         spa->spa_inject_ref--;
3089         mutex_exit(&spa_namespace_lock);
3090 }
3091 
3092 /*
3093  * Add spares device information to the nvlist.
3094  */
3095 static void
3096 spa_add_spares(spa_t *spa, nvlist_t *config)
3097 {
3098         nvlist_t **spares;
3099         uint_t i, nspares;
3100         nvlist_t *nvroot;
3101         uint64_t guid;
3102         vdev_stat_t *vs;
3103         uint_t vsc;
3104         uint64_t pool;
3105 
3106         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3107 
3108         if (spa->spa_spares.sav_count == 0)
3109                 return;
3110 
3111         VERIFY(nvlist_lookup_nvlist(config,
3112             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3113         VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
3114             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
3115         if (nspares != 0) {
3116                 VERIFY(nvlist_add_nvlist_array(nvroot,
3117                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3118                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
3119                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
3120 
3121                 /*
3122                  * Go through and find any spares which have since been
3123                  * repurposed as an active spare.  If this is the case, update
3124                  * their status appropriately.
3125                  */
3126                 for (i = 0; i < nspares; i++) {
3127                         VERIFY(nvlist_lookup_uint64(spares[i],
3128                             ZPOOL_CONFIG_GUID, &guid) == 0);
3129                         if (spa_spare_exists(guid, &pool, NULL) &&
3130                             pool != 0ULL) {
3131                                 VERIFY(nvlist_lookup_uint64_array(
3132                                     spares[i], ZPOOL_CONFIG_VDEV_STATS,
3133                                     (uint64_t **)&vs, &vsc) == 0);
3134                                 vs->vs_state = VDEV_STATE_CANT_OPEN;
3135                                 vs->vs_aux = VDEV_AUX_SPARED;
3136                         }
3137                 }
3138         }
3139 }
3140 
3141 /*
3142  * Add l2cache device information to the nvlist, including vdev stats.
3143  */
3144 static void
3145 spa_add_l2cache(spa_t *spa, nvlist_t *config)
3146 {
3147         nvlist_t **l2cache;
3148         uint_t i, j, nl2cache;
3149         nvlist_t *nvroot;
3150         uint64_t guid;
3151         vdev_t *vd;
3152         vdev_stat_t *vs;
3153         uint_t vsc;
3154 
3155         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3156 
3157         if (spa->spa_l2cache.sav_count == 0)
3158                 return;
3159 
3160         VERIFY(nvlist_lookup_nvlist(config,
3161             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3162         VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
3163             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3164         if (nl2cache != 0) {
3165                 VERIFY(nvlist_add_nvlist_array(nvroot,
3166                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3167                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
3168                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3169 
3170                 /*
3171                  * Update level 2 cache device stats.
3172                  */
3173 
3174                 for (i = 0; i < nl2cache; i++) {
3175                         VERIFY(nvlist_lookup_uint64(l2cache[i],
3176                             ZPOOL_CONFIG_GUID, &guid) == 0);
3177 
3178                         vd = NULL;
3179                         for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
3180                                 if (guid ==
3181                                     spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
3182                                         vd = spa->spa_l2cache.sav_vdevs[j];
3183                                         break;
3184                                 }
3185                         }
3186                         ASSERT(vd != NULL);
3187 
3188                         VERIFY(nvlist_lookup_uint64_array(l2cache[i],
3189                             ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc)
3190                             == 0);
3191                         vdev_get_stats(vd, vs);
3192                 }
3193         }
3194 }
3195 
3196 static void
3197 spa_add_feature_stats(spa_t *spa, nvlist_t *config)
3198 {
3199         nvlist_t *features;
3200         zap_cursor_t zc;
3201         zap_attribute_t za;
3202 
3203         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3204         VERIFY(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3205 
3206         if (spa->spa_feat_for_read_obj != 0) {
3207                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3208                     spa->spa_feat_for_read_obj);
3209                     zap_cursor_retrieve(&zc, &za) == 0;
3210                     zap_cursor_advance(&zc)) {
3211                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3212                             za.za_num_integers == 1);
3213                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3214                             za.za_first_integer));
3215                 }
3216                 zap_cursor_fini(&zc);
3217         }
3218 
3219         if (spa->spa_feat_for_write_obj != 0) {
3220                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3221                     spa->spa_feat_for_write_obj);
3222                     zap_cursor_retrieve(&zc, &za) == 0;
3223                     zap_cursor_advance(&zc)) {
3224                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3225                             za.za_num_integers == 1);
3226                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3227                             za.za_first_integer));
3228                 }
3229                 zap_cursor_fini(&zc);
3230         }
3231 
3232         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
3233             features) == 0);
3234         nvlist_free(features);
3235 }
3236 
3237 int
3238 spa_get_stats(const char *name, nvlist_t **config,
3239     char *altroot, size_t buflen)
3240 {
3241         int error;
3242         spa_t *spa;
3243 
3244         *config = NULL;
3245         error = spa_open_common(name, &spa, FTAG, NULL, config);
3246 
3247         if (spa != NULL) {
3248                 /*
3249                  * This still leaves a window of inconsistency where the spares
3250                  * or l2cache devices could change and the config would be
3251                  * self-inconsistent.
3252                  */
3253                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3254 
3255                 if (*config != NULL) {
3256                         uint64_t loadtimes[2];
3257 
3258                         loadtimes[0] = spa->spa_loaded_ts.tv_sec;
3259                         loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
3260                         VERIFY(nvlist_add_uint64_array(*config,
3261                             ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2) == 0);
3262 
3263                         VERIFY(nvlist_add_uint64(*config,
3264                             ZPOOL_CONFIG_ERRCOUNT,
3265                             spa_get_errlog_size(spa)) == 0);
3266 
3267                         if (spa_suspended(spa))
3268                                 VERIFY(nvlist_add_uint64(*config,
3269                                     ZPOOL_CONFIG_SUSPENDED,
3270                                     spa->spa_failmode) == 0);
3271 
3272                         spa_add_spares(spa, *config);
3273                         spa_add_l2cache(spa, *config);
3274                         spa_add_feature_stats(spa, *config);
3275                 }
3276         }
3277 
3278         /*
3279          * We want to get the alternate root even for faulted pools, so we cheat
3280          * and call spa_lookup() directly.
3281          */
3282         if (altroot) {
3283                 if (spa == NULL) {
3284                         mutex_enter(&spa_namespace_lock);
3285                         spa = spa_lookup(name);
3286                         if (spa)
3287                                 spa_altroot(spa, altroot, buflen);
3288                         else
3289                                 altroot[0] = '\0';
3290                         spa = NULL;
3291                         mutex_exit(&spa_namespace_lock);
3292                 } else {
3293                         spa_altroot(spa, altroot, buflen);
3294                 }
3295         }
3296 
3297         if (spa != NULL) {
3298                 spa_config_exit(spa, SCL_CONFIG, FTAG);
3299                 spa_close(spa, FTAG);
3300         }
3301 
3302         return (error);
3303 }
3304 
3305 /*
3306  * Validate that the auxiliary device array is well formed.  We must have an
3307  * array of nvlists, each which describes a valid leaf vdev.  If this is an
3308  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
3309  * specified, as long as they are well-formed.
3310  */
3311 static int
3312 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
3313     spa_aux_vdev_t *sav, const char *config, uint64_t version,
3314     vdev_labeltype_t label)
3315 {
3316         nvlist_t **dev;
3317         uint_t i, ndev;
3318         vdev_t *vd;
3319         int error;
3320 
3321         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3322 
3323         /*
3324          * It's acceptable to have no devs specified.
3325          */
3326         if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
3327                 return (0);
3328 
3329         if (ndev == 0)
3330                 return (SET_ERROR(EINVAL));
3331 
3332         /*
3333          * Make sure the pool is formatted with a version that supports this
3334          * device type.
3335          */
3336         if (spa_version(spa) < version)
3337                 return (SET_ERROR(ENOTSUP));
3338 
3339         /*
3340          * Set the pending device list so we correctly handle device in-use
3341          * checking.
3342          */
3343         sav->sav_pending = dev;
3344         sav->sav_npending = ndev;
3345 
3346         for (i = 0; i < ndev; i++) {
3347                 if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
3348                     mode)) != 0)
3349                         goto out;
3350 
3351                 if (!vd->vdev_ops->vdev_op_leaf) {
3352                         vdev_free(vd);
3353                         error = SET_ERROR(EINVAL);
3354                         goto out;
3355                 }
3356 
3357                 /*
3358                  * The L2ARC currently only supports disk devices in
3359                  * kernel context.  For user-level testing, we allow it.
3360                  */
3361 #ifdef _KERNEL
3362                 if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
3363                     strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
3364                         error = SET_ERROR(ENOTBLK);
3365                         vdev_free(vd);
3366                         goto out;
3367                 }
3368 #endif
3369                 vd->vdev_top = vd;
3370 
3371                 if ((error = vdev_open(vd)) == 0 &&
3372                     (error = vdev_label_init(vd, crtxg, label)) == 0) {
3373                         VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
3374                             vd->vdev_guid) == 0);
3375                 }
3376 
3377                 vdev_free(vd);
3378 
3379                 if (error &&
3380                     (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
3381                         goto out;
3382                 else
3383                         error = 0;
3384         }
3385 
3386 out:
3387         sav->sav_pending = NULL;
3388         sav->sav_npending = 0;
3389         return (error);
3390 }
3391 
3392 static int
3393 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
3394 {
3395         int error;
3396 
3397         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3398 
3399         if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3400             &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
3401             VDEV_LABEL_SPARE)) != 0) {
3402                 return (error);
3403         }
3404 
3405         return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3406             &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
3407             VDEV_LABEL_L2CACHE));
3408 }
3409 
3410 static void
3411 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
3412     const char *config)
3413 {
3414         int i;
3415 
3416         if (sav->sav_config != NULL) {
3417                 nvlist_t **olddevs;
3418                 uint_t oldndevs;
3419                 nvlist_t **newdevs;
3420 
3421                 /*
3422                  * Generate new dev list by concatentating with the
3423                  * current dev list.
3424                  */
3425                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
3426                     &olddevs, &oldndevs) == 0);
3427 
3428                 newdevs = kmem_alloc(sizeof (void *) *
3429                     (ndevs + oldndevs), KM_SLEEP);
3430                 for (i = 0; i < oldndevs; i++)
3431                         VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
3432                             KM_SLEEP) == 0);
3433                 for (i = 0; i < ndevs; i++)
3434                         VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
3435                             KM_SLEEP) == 0);
3436 
3437                 VERIFY(nvlist_remove(sav->sav_config, config,
3438                     DATA_TYPE_NVLIST_ARRAY) == 0);
3439 
3440                 VERIFY(nvlist_add_nvlist_array(sav->sav_config,
3441                     config, newdevs, ndevs + oldndevs) == 0);
3442                 for (i = 0; i < oldndevs + ndevs; i++)
3443                         nvlist_free(newdevs[i]);
3444                 kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
3445         } else {
3446                 /*
3447                  * Generate a new dev list.
3448                  */
3449                 VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
3450                     KM_SLEEP) == 0);
3451                 VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
3452                     devs, ndevs) == 0);
3453         }
3454 }
3455 
3456 /*
3457  * Stop and drop level 2 ARC devices
3458  */
3459 void
3460 spa_l2cache_drop(spa_t *spa)
3461 {
3462         vdev_t *vd;
3463         int i;
3464         spa_aux_vdev_t *sav = &spa->spa_l2cache;
3465 
3466         for (i = 0; i < sav->sav_count; i++) {
3467                 uint64_t pool;
3468 
3469                 vd = sav->sav_vdevs[i];
3470                 ASSERT(vd != NULL);
3471 
3472                 if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
3473                     pool != 0ULL && l2arc_vdev_present(vd))
3474                         l2arc_remove_vdev(vd);
3475         }
3476 }
3477 
3478 /*
3479  * Pool Creation
3480  */
3481 int
3482 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
3483     nvlist_t *zplprops)
3484 {
3485         spa_t *spa;
3486         char *altroot = NULL;
3487         vdev_t *rvd;
3488         dsl_pool_t *dp;
3489         dmu_tx_t *tx;
3490         int error = 0;
3491         uint64_t txg = TXG_INITIAL;
3492         nvlist_t **spares, **l2cache;
3493         uint_t nspares, nl2cache;
3494         uint64_t version, obj;
3495         boolean_t has_features;
3496 
3497         /*
3498          * If this pool already exists, return failure.
3499          */
3500         mutex_enter(&spa_namespace_lock);
3501         if (spa_lookup(pool) != NULL) {
3502                 mutex_exit(&spa_namespace_lock);
3503                 return (SET_ERROR(EEXIST));
3504         }
3505 
3506         /*
3507          * Allocate a new spa_t structure.
3508          */
3509         (void) nvlist_lookup_string(props,
3510             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3511         spa = spa_add(pool, NULL, altroot);
3512         spa_activate(spa, spa_mode_global);
3513 
3514         if (props && (error = spa_prop_validate(spa, props))) {
3515                 spa_deactivate(spa);
3516                 spa_remove(spa);
3517                 mutex_exit(&spa_namespace_lock);
3518                 return (error);
3519         }
3520 
3521         has_features = B_FALSE;
3522         for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
3523             elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
3524                 if (zpool_prop_feature(nvpair_name(elem)))
3525                         has_features = B_TRUE;
3526         }
3527 
3528         if (has_features || nvlist_lookup_uint64(props,
3529             zpool_prop_to_name(ZPOOL_PROP_VERSION), &version) != 0) {
3530                 version = SPA_VERSION;
3531         }
3532         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
3533 
3534         spa->spa_first_txg = txg;
3535         spa->spa_uberblock.ub_txg = txg - 1;
3536         spa->spa_uberblock.ub_version = version;
3537         spa->spa_ubsync = spa->spa_uberblock;
3538 
3539         /*
3540          * Create "The Godfather" zio to hold all async IOs
3541          */
3542         spa->spa_async_zio_root = kmem_alloc(max_ncpus * sizeof (void *),
3543             KM_SLEEP);
3544         for (int i = 0; i < max_ncpus; i++) {
3545                 spa->spa_async_zio_root[i] = zio_root(spa, NULL, NULL,
3546                     ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
3547                     ZIO_FLAG_GODFATHER);
3548         }
3549 
3550         /*
3551          * Create the root vdev.
3552          */
3553         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3554 
3555         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
3556 
3557         ASSERT(error != 0 || rvd != NULL);
3558         ASSERT(error != 0 || spa->spa_root_vdev == rvd);
3559 
3560         if (error == 0 && !zfs_allocatable_devs(nvroot))
3561                 error = SET_ERROR(EINVAL);
3562 
3563         if (error == 0 &&
3564             (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
3565             (error = spa_validate_aux(spa, nvroot, txg,
3566             VDEV_ALLOC_ADD)) == 0) {
3567                 for (int c = 0; c < rvd->vdev_children; c++) {
3568                         vdev_metaslab_set_size(rvd->vdev_child[c]);
3569                         vdev_expand(rvd->vdev_child[c], txg);
3570                 }
3571         }
3572 
3573         spa_config_exit(spa, SCL_ALL, FTAG);
3574 
3575         if (error != 0) {
3576                 spa_unload(spa);
3577                 spa_deactivate(spa);
3578                 spa_remove(spa);
3579                 mutex_exit(&spa_namespace_lock);
3580                 return (error);
3581         }
3582 
3583         /*
3584          * Get the list of spares, if specified.
3585          */
3586         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3587             &spares, &nspares) == 0) {
3588                 VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
3589                     KM_SLEEP) == 0);
3590                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3591                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3592                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3593                 spa_load_spares(spa);
3594                 spa_config_exit(spa, SCL_ALL, FTAG);
3595                 spa->spa_spares.sav_sync = B_TRUE;
3596         }
3597 
3598         /*
3599          * Get the list of level 2 cache devices, if specified.
3600          */
3601         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3602             &l2cache, &nl2cache) == 0) {
3603                 VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3604                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
3605                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3606                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3607                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3608                 spa_load_l2cache(spa);
3609                 spa_config_exit(spa, SCL_ALL, FTAG);
3610                 spa->spa_l2cache.sav_sync = B_TRUE;
3611         }
3612 
3613         spa->spa_is_initializing = B_TRUE;
3614         spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
3615         spa->spa_meta_objset = dp->dp_meta_objset;
3616         spa->spa_is_initializing = B_FALSE;
3617 
3618         /*
3619          * Create DDTs (dedup tables).
3620          */
3621         ddt_create(spa);
3622 
3623         spa_update_dspace(spa);
3624 
3625         tx = dmu_tx_create_assigned(dp, txg);
3626 
3627         /*
3628          * Create the pool config object.
3629          */
3630         spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
3631             DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
3632             DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
3633 
3634         if (zap_add(spa->spa_meta_objset,
3635             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
3636             sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
3637                 cmn_err(CE_PANIC, "failed to add pool config");
3638         }
3639 
3640         if (spa_version(spa) >= SPA_VERSION_FEATURES)
3641                 spa_feature_create_zap_objects(spa, tx);
3642 
3643         if (zap_add(spa->spa_meta_objset,
3644             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
3645             sizeof (uint64_t), 1, &version, tx) != 0) {
3646                 cmn_err(CE_PANIC, "failed to add pool version");
3647         }
3648 
3649         /* Newly created pools with the right version are always deflated. */
3650         if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
3651                 spa->spa_deflate = TRUE;
3652                 if (zap_add(spa->spa_meta_objset,
3653                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
3654                     sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
3655                         cmn_err(CE_PANIC, "failed to add deflate");
3656                 }
3657         }
3658 
3659         /*
3660          * Create the deferred-free bpobj.  Turn off compression
3661          * because sync-to-convergence takes longer if the blocksize
3662          * keeps changing.
3663          */
3664         obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
3665         dmu_object_set_compress(spa->spa_meta_objset, obj,
3666             ZIO_COMPRESS_OFF, tx);
3667         if (zap_add(spa->spa_meta_objset,
3668             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
3669             sizeof (uint64_t), 1, &obj, tx) != 0) {
3670                 cmn_err(CE_PANIC, "failed to add bpobj");
3671         }
3672         VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
3673             spa->spa_meta_objset, obj));
3674 
3675         /*
3676          * Create the pool's history object.
3677          */
3678         if (version >= SPA_VERSION_ZPOOL_HISTORY)
3679                 spa_history_create_obj(spa, tx);
3680 
3681         /*
3682          * Generate some random noise for salted checksums to operate on.
3683          */
3684         (void) random_get_pseudo_bytes(spa->spa_cksum_salt.zcs_bytes,
3685             sizeof (spa->spa_cksum_salt.zcs_bytes));
3686 
3687         /*
3688          * Set pool properties.
3689          */
3690         spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
3691         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
3692         spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
3693         spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
3694 
3695         if (props != NULL) {
3696                 spa_configfile_set(spa, props, B_FALSE);
3697                 spa_sync_props(props, tx);
3698         }
3699 
3700         dmu_tx_commit(tx);
3701 
3702         spa->spa_sync_on = B_TRUE;
3703         txg_sync_start(spa->spa_dsl_pool);
3704 
3705         /*
3706          * We explicitly wait for the first transaction to complete so that our
3707          * bean counters are appropriately updated.
3708          */
3709         txg_wait_synced(spa->spa_dsl_pool, txg);
3710 
3711         spa_config_sync(spa, B_FALSE, B_TRUE);
3712         spa_event_notify(spa, NULL, ESC_ZFS_POOL_CREATE);
3713 
3714         spa_history_log_version(spa, "create");
3715 
3716         /*
3717          * Don't count references from objsets that are already closed
3718          * and are making their way through the eviction process.
3719          */
3720         spa_evicting_os_wait(spa);
3721         spa->spa_minref = refcount_count(&spa->spa_refcount);
3722 
3723         mutex_exit(&spa_namespace_lock);
3724 
3725         return (0);
3726 }
3727 
3728 #ifdef _KERNEL
3729 /*
3730  * Get the root pool information from the root disk, then import the root pool
3731  * during the system boot up time.
3732  */
3733 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
3734 
3735 static nvlist_t *
3736 spa_generate_rootconf(char *devpath, char *devid, uint64_t *guid)
3737 {
3738         nvlist_t *config;
3739         nvlist_t *nvtop, *nvroot;
3740         uint64_t pgid;
3741 
3742         if (vdev_disk_read_rootlabel(devpath, devid, &config) != 0)
3743                 return (NULL);
3744 
3745         /*
3746          * Add this top-level vdev to the child array.
3747          */
3748         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3749             &nvtop) == 0);
3750         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
3751             &pgid) == 0);
3752         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, guid) == 0);
3753 
3754         /*
3755          * Put this pool's top-level vdevs into a root vdev.
3756          */
3757         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3758         VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
3759             VDEV_TYPE_ROOT) == 0);
3760         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
3761         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
3762         VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
3763             &nvtop, 1) == 0);
3764 
3765         /*
3766          * Replace the existing vdev_tree with the new root vdev in
3767          * this pool's configuration (remove the old, add the new).
3768          */
3769         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
3770         nvlist_free(nvroot);
3771         return (config);
3772 }
3773 
3774 /*
3775  * Walk the vdev tree and see if we can find a device with "better"
3776  * configuration. A configuration is "better" if the label on that
3777  * device has a more recent txg.
3778  */
3779 static void
3780 spa_alt_rootvdev(vdev_t *vd, vdev_t **avd, uint64_t *txg)
3781 {
3782         for (int c = 0; c < vd->vdev_children; c++)
3783                 spa_alt_rootvdev(vd->vdev_child[c], avd, txg);
3784 
3785         if (vd->vdev_ops->vdev_op_leaf) {
3786                 nvlist_t *label;
3787                 uint64_t label_txg;
3788 
3789                 if (vdev_disk_read_rootlabel(vd->vdev_physpath, vd->vdev_devid,
3790                     &label) != 0)
3791                         return;
3792 
3793                 VERIFY(nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
3794                     &label_txg) == 0);
3795 
3796                 /*
3797                  * Do we have a better boot device?
3798                  */
3799                 if (label_txg > *txg) {
3800                         *txg = label_txg;
3801                         *avd = vd;
3802                 }
3803                 nvlist_free(label);
3804         }
3805 }
3806 
3807 /*
3808  * Import a root pool.
3809  *
3810  * For x86. devpath_list will consist of devid and/or physpath name of
3811  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
3812  * The GRUB "findroot" command will return the vdev we should boot.
3813  *
3814  * For Sparc, devpath_list consists the physpath name of the booting device
3815  * no matter the rootpool is a single device pool or a mirrored pool.
3816  * e.g.
3817  *      "/pci@1f,0/ide@d/disk@0,0:a"
3818  */
3819 int
3820 spa_import_rootpool(char *devpath, char *devid)
3821 {
3822         spa_t *spa;
3823         vdev_t *rvd, *bvd, *avd = NULL;
3824         nvlist_t *config, *nvtop;
3825         uint64_t guid, txg;
3826         char *pname;
3827         int error;
3828 
3829         /*
3830          * Read the label from the boot device and generate a configuration.
3831          */
3832         config = spa_generate_rootconf(devpath, devid, &guid);
3833 #if defined(_OBP) && defined(_KERNEL)
3834         if (config == NULL) {
3835                 if (strstr(devpath, "/iscsi/ssd") != NULL) {
3836                         /* iscsi boot */
3837                         get_iscsi_bootpath_phy(devpath);
3838                         config = spa_generate_rootconf(devpath, devid, &guid);
3839                 }
3840         }
3841 #endif
3842         if (config == NULL) {
3843                 cmn_err(CE_NOTE, "Cannot read the pool label from '%s'",
3844                     devpath);
3845                 return (SET_ERROR(EIO));
3846         }
3847 
3848         VERIFY(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
3849             &pname) == 0);
3850         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
3851 
3852         mutex_enter(&spa_namespace_lock);
3853         if ((spa = spa_lookup(pname)) != NULL) {
3854                 /*
3855                  * Remove the existing root pool from the namespace so that we
3856                  * can replace it with the correct config we just read in.
3857                  */
3858                 spa_remove(spa);
3859         }
3860 
3861         spa = spa_add(pname, config, NULL);
3862         spa->spa_is_root = B_TRUE;
3863         spa->spa_import_flags = ZFS_IMPORT_VERBATIM;
3864 
3865         /*
3866          * Build up a vdev tree based on the boot device's label config.
3867          */
3868         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3869             &nvtop) == 0);
3870         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3871         error = spa_config_parse(spa, &rvd, nvtop, NULL, 0,
3872             VDEV_ALLOC_ROOTPOOL);
3873         spa_config_exit(spa, SCL_ALL, FTAG);
3874         if (error) {
3875                 mutex_exit(&spa_namespace_lock);
3876                 nvlist_free(config);
3877                 cmn_err(CE_NOTE, "Can not parse the config for pool '%s'",
3878                     pname);
3879                 return (error);
3880         }
3881 
3882         /*
3883          * Get the boot vdev.
3884          */
3885         if ((bvd = vdev_lookup_by_guid(rvd, guid)) == NULL) {
3886                 cmn_err(CE_NOTE, "Can not find the boot vdev for guid %llu",
3887                     (u_longlong_t)guid);
3888                 error = SET_ERROR(ENOENT);
3889                 goto out;
3890         }
3891 
3892         /*
3893          * Determine if there is a better boot device.
3894          */
3895         avd = bvd;
3896         spa_alt_rootvdev(rvd, &avd, &txg);
3897         if (avd != bvd) {
3898                 cmn_err(CE_NOTE, "The boot device is 'degraded'. Please "
3899                     "try booting from '%s'", avd->vdev_path);
3900                 error = SET_ERROR(EINVAL);
3901                 goto out;
3902         }
3903 
3904         /*
3905          * If the boot device is part of a spare vdev then ensure that
3906          * we're booting off the active spare.
3907          */
3908         if (bvd->vdev_parent->vdev_ops == &vdev_spare_ops &&
3909             !bvd->vdev_isspare) {
3910                 cmn_err(CE_NOTE, "The boot device is currently spared. Please "
3911                     "try booting from '%s'",
3912                     bvd->vdev_parent->
3913                     vdev_child[bvd->vdev_parent->vdev_children - 1]->vdev_path);
3914                 error = SET_ERROR(EINVAL);
3915                 goto out;
3916         }
3917 
3918         error = 0;
3919 out:
3920         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3921         vdev_free(rvd);
3922         spa_config_exit(spa, SCL_ALL, FTAG);
3923         mutex_exit(&spa_namespace_lock);
3924 
3925         nvlist_free(config);
3926         return (error);
3927 }
3928 
3929 #endif
3930 
3931 /*
3932  * Import a non-root pool into the system.
3933  */
3934 int
3935 spa_import(const char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
3936 {
3937         spa_t *spa;
3938         char *altroot = NULL;
3939         spa_load_state_t state = SPA_LOAD_IMPORT;
3940         zpool_rewind_policy_t policy;
3941         uint64_t mode = spa_mode_global;
3942         uint64_t readonly = B_FALSE;
3943         int error;
3944         nvlist_t *nvroot;
3945         nvlist_t **spares, **l2cache;
3946         uint_t nspares, nl2cache;
3947 
3948         /*
3949          * If a pool with this name exists, return failure.
3950          */
3951         mutex_enter(&spa_namespace_lock);
3952         if (spa_lookup(pool) != NULL) {
3953                 mutex_exit(&spa_namespace_lock);
3954                 return (SET_ERROR(EEXIST));
3955         }
3956 
3957         /*
3958          * Create and initialize the spa structure.
3959          */
3960         (void) nvlist_lookup_string(props,
3961             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3962         (void) nvlist_lookup_uint64(props,
3963             zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
3964         if (readonly)
3965                 mode = FREAD;
3966         spa = spa_add(pool, config, altroot);
3967         spa->spa_import_flags = flags;
3968 
3969         /*
3970          * Verbatim import - Take a pool and insert it into the namespace
3971          * as if it had been loaded at boot.
3972          */
3973         if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
3974                 if (props != NULL)
3975                         spa_configfile_set(spa, props, B_FALSE);
3976 
3977                 spa_config_sync(spa, B_FALSE, B_TRUE);
3978                 spa_event_notify(spa, NULL, ESC_ZFS_POOL_IMPORT);
3979 
3980                 mutex_exit(&spa_namespace_lock);
3981                 return (0);
3982         }
3983 
3984         spa_activate(spa, mode);
3985 
3986         /*
3987          * Don't start async tasks until we know everything is healthy.
3988          */
3989         spa_async_suspend(spa);
3990 
3991         zpool_get_rewind_policy(config, &policy);
3992         if (policy.zrp_request & ZPOOL_DO_REWIND)
3993                 state = SPA_LOAD_RECOVER;
3994 
3995         /*
3996          * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
3997          * because the user-supplied config is actually the one to trust when
3998          * doing an import.
3999          */
4000         if (state != SPA_LOAD_RECOVER)
4001                 spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
4002 
4003         error = spa_load_best(spa, state, B_TRUE, policy.zrp_txg,
4004             policy.zrp_request);
4005 
4006         /*
4007          * Propagate anything learned while loading the pool and pass it
4008          * back to caller (i.e. rewind info, missing devices, etc).
4009          */
4010         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
4011             spa->spa_load_info) == 0);
4012 
4013         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4014         /*
4015          * Toss any existing sparelist, as it doesn't have any validity
4016          * anymore, and conflicts with spa_has_spare().
4017          */
4018         if (spa->spa_spares.sav_config) {
4019                 nvlist_free(spa->spa_spares.sav_config);
4020                 spa->spa_spares.sav_config = NULL;
4021                 spa_load_spares(spa);
4022         }
4023         if (spa->spa_l2cache.sav_config) {
4024                 nvlist_free(spa->spa_l2cache.sav_config);
4025                 spa->spa_l2cache.sav_config = NULL;
4026                 spa_load_l2cache(spa);
4027         }
4028 
4029         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
4030             &nvroot) == 0);
4031         if (error == 0)
4032                 error = spa_validate_aux(spa, nvroot, -1ULL,
4033                     VDEV_ALLOC_SPARE);
4034         if (error == 0)
4035                 error = spa_validate_aux(spa, nvroot, -1ULL,
4036                     VDEV_ALLOC_L2CACHE);
4037         spa_config_exit(spa, SCL_ALL, FTAG);
4038 
4039         if (props != NULL)
4040                 spa_configfile_set(spa, props, B_FALSE);
4041 
4042         if (error != 0 || (props && spa_writeable(spa) &&
4043             (error = spa_prop_set(spa, props)))) {
4044                 spa_unload(spa);
4045                 spa_deactivate(spa);
4046                 spa_remove(spa);
4047                 mutex_exit(&spa_namespace_lock);
4048                 return (error);
4049         }
4050 
4051         spa_async_resume(spa);
4052 
4053         /*
4054          * Override any spares and level 2 cache devices as specified by
4055          * the user, as these may have correct device names/devids, etc.
4056          */
4057         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
4058             &spares, &nspares) == 0) {
4059                 if (spa->spa_spares.sav_config)
4060                         VERIFY(nvlist_remove(spa->spa_spares.sav_config,
4061                             ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
4062                 else
4063                         VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
4064                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
4065                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
4066                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
4067                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4068                 spa_load_spares(spa);
4069                 spa_config_exit(spa, SCL_ALL, FTAG);
4070                 spa->spa_spares.sav_sync = B_TRUE;
4071         }
4072         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
4073             &l2cache, &nl2cache) == 0) {
4074                 if (spa->spa_l2cache.sav_config)
4075                         VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
4076                             ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
4077                 else
4078                         VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
4079                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
4080                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
4081                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
4082                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4083                 spa_load_l2cache(spa);
4084                 spa_config_exit(spa, SCL_ALL, FTAG);
4085                 spa->spa_l2cache.sav_sync = B_TRUE;
4086         }
4087 
4088         /*
4089          * Check for any removed devices.
4090          */
4091         if (spa->spa_autoreplace) {
4092                 spa_aux_check_removed(&spa->spa_spares);
4093                 spa_aux_check_removed(&spa->spa_l2cache);
4094         }
4095 
4096         if (spa_writeable(spa)) {
4097                 /*
4098                  * Update the config cache to include the newly-imported pool.
4099                  */
4100                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4101         }
4102 
4103         /*
4104          * It's possible that the pool was expanded while it was exported.
4105          * We kick off an async task to handle this for us.
4106          */
4107         spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
4108 
4109         spa_history_log_version(spa, "import");
4110 
4111         spa_event_notify(spa, NULL, ESC_ZFS_POOL_IMPORT);
4112 
4113         mutex_exit(&spa_namespace_lock);
4114 
4115         return (0);
4116 }
4117 
4118 nvlist_t *
4119 spa_tryimport(nvlist_t *tryconfig)
4120 {
4121         nvlist_t *config = NULL;
4122         char *poolname;
4123         spa_t *spa;
4124         uint64_t state;
4125         int error;
4126 
4127         if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
4128                 return (NULL);
4129 
4130         if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
4131                 return (NULL);
4132 
4133         /*
4134          * Create and initialize the spa structure.
4135          */
4136         mutex_enter(&spa_namespace_lock);
4137         spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
4138         spa_activate(spa, FREAD);
4139 
4140         /*
4141          * Pass off the heavy lifting to spa_load().
4142          * Pass TRUE for mosconfig because the user-supplied config
4143          * is actually the one to trust when doing an import.
4144          */
4145         error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING, B_TRUE);
4146 
4147         /*
4148          * If 'tryconfig' was at least parsable, return the current config.
4149          */
4150         if (spa->spa_root_vdev != NULL) {
4151                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
4152                 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
4153                     poolname) == 0);
4154                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4155                     state) == 0);
4156                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
4157                     spa->spa_uberblock.ub_timestamp) == 0);
4158                 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
4159                     spa->spa_load_info) == 0);
4160 
4161                 /*
4162                  * If the bootfs property exists on this pool then we
4163                  * copy it out so that external consumers can tell which
4164                  * pools are bootable.
4165                  */
4166                 if ((!error || error == EEXIST) && spa->spa_bootfs) {
4167                         char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4168 
4169                         /*
4170                          * We have to play games with the name since the
4171                          * pool was opened as TRYIMPORT_NAME.
4172                          */
4173                         if (dsl_dsobj_to_dsname(spa_name(spa),
4174                             spa->spa_bootfs, tmpname) == 0) {
4175                                 char *cp;
4176                                 char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4177 
4178                                 cp = strchr(tmpname, '/');
4179                                 if (cp == NULL) {
4180                                         (void) strlcpy(dsname, tmpname,
4181                                             MAXPATHLEN);
4182                                 } else {
4183                                         (void) snprintf(dsname, MAXPATHLEN,
4184                                             "%s/%s", poolname, ++cp);
4185                                 }
4186                                 VERIFY(nvlist_add_string(config,
4187                                     ZPOOL_CONFIG_BOOTFS, dsname) == 0);
4188                                 kmem_free(dsname, MAXPATHLEN);
4189                         }
4190                         kmem_free(tmpname, MAXPATHLEN);
4191                 }
4192 
4193                 /*
4194                  * Add the list of hot spares and level 2 cache devices.
4195                  */
4196                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
4197                 spa_add_spares(spa, config);
4198                 spa_add_l2cache(spa, config);
4199                 spa_config_exit(spa, SCL_CONFIG, FTAG);
4200         }
4201 
4202         spa_unload(spa);
4203         spa_deactivate(spa);
4204         spa_remove(spa);
4205         mutex_exit(&spa_namespace_lock);
4206 
4207         return (config);
4208 }
4209 
4210 /*
4211  * Pool export/destroy
4212  *
4213  * The act of destroying or exporting a pool is very simple.  We make sure there
4214  * is no more pending I/O and any references to the pool are gone.  Then, we
4215  * update the pool state and sync all the labels to disk, removing the
4216  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
4217  * we don't sync the labels or remove the configuration cache.
4218  */
4219 static int
4220 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
4221     boolean_t force, boolean_t hardforce)
4222 {
4223         spa_t *spa;
4224 
4225         if (oldconfig)
4226                 *oldconfig = NULL;
4227 
4228         if (!(spa_mode_global & FWRITE))
4229                 return (SET_ERROR(EROFS));
4230 
4231         mutex_enter(&spa_namespace_lock);
4232         if ((spa = spa_lookup(pool)) == NULL) {
4233                 mutex_exit(&spa_namespace_lock);
4234                 return (SET_ERROR(ENOENT));
4235         }
4236 
4237         /*
4238          * Put a hold on the pool, drop the namespace lock, stop async tasks,
4239          * reacquire the namespace lock, and see if we can export.
4240          */
4241         spa_open_ref(spa, FTAG);
4242         mutex_exit(&spa_namespace_lock);
4243         spa_async_suspend(spa);
4244         mutex_enter(&spa_namespace_lock);
4245         spa_close(spa, FTAG);
4246 
4247         /*
4248          * The pool will be in core if it's openable,
4249          * in which case we can modify its state.
4250          */
4251         if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
4252                 /*
4253                  * Objsets may be open only because they're dirty, so we
4254                  * have to force it to sync before checking spa_refcnt.
4255                  */
4256                 txg_wait_synced(spa->spa_dsl_pool, 0);
4257                 spa_evicting_os_wait(spa);
4258 
4259                 /*
4260                  * A pool cannot be exported or destroyed if there are active
4261                  * references.  If we are resetting a pool, allow references by
4262                  * fault injection handlers.
4263                  */
4264                 if (!spa_refcount_zero(spa) ||
4265                     (spa->spa_inject_ref != 0 &&
4266                     new_state != POOL_STATE_UNINITIALIZED)) {
4267                         spa_async_resume(spa);
4268                         mutex_exit(&spa_namespace_lock);
4269                         return (SET_ERROR(EBUSY));
4270                 }
4271 
4272                 /*
4273                  * A pool cannot be exported if it has an active shared spare.
4274                  * This is to prevent other pools stealing the active spare
4275                  * from an exported pool. At user's own will, such pool can
4276                  * be forcedly exported.
4277                  */
4278                 if (!force && new_state == POOL_STATE_EXPORTED &&
4279                     spa_has_active_shared_spare(spa)) {
4280                         spa_async_resume(spa);
4281                         mutex_exit(&spa_namespace_lock);
4282                         return (SET_ERROR(EXDEV));
4283                 }
4284 
4285                 /*
4286                  * We want this to be reflected on every label,
4287                  * so mark them all dirty.  spa_unload() will do the
4288                  * final sync that pushes these changes out.
4289                  */
4290                 if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
4291                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4292                         spa->spa_state = new_state;
4293                         spa->spa_final_txg = spa_last_synced_txg(spa) +
4294                             TXG_DEFER_SIZE + 1;
4295                         vdev_config_dirty(spa->spa_root_vdev);
4296                         spa_config_exit(spa, SCL_ALL, FTAG);
4297                 }
4298         }
4299 
4300         spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
4301 
4302         if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
4303                 spa_unload(spa);
4304                 spa_deactivate(spa);
4305         }
4306 
4307         if (oldconfig && spa->spa_config)
4308                 VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
4309 
4310         if (new_state != POOL_STATE_UNINITIALIZED) {
4311                 if (!hardforce)
4312                         spa_config_sync(spa, B_TRUE, B_TRUE);
4313                 spa_remove(spa);
4314         }
4315         mutex_exit(&spa_namespace_lock);
4316 
4317         return (0);
4318 }
4319 
4320 /*
4321  * Destroy a storage pool.
4322  */
4323 int
4324 spa_destroy(char *pool)
4325 {
4326         return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
4327             B_FALSE, B_FALSE));
4328 }
4329 
4330 /*
4331  * Export a storage pool.
4332  */
4333 int
4334 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
4335     boolean_t hardforce)
4336 {
4337         return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
4338             force, hardforce));
4339 }
4340 
4341 /*
4342  * Similar to spa_export(), this unloads the spa_t without actually removing it
4343  * from the namespace in any way.
4344  */
4345 int
4346 spa_reset(char *pool)
4347 {
4348         return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
4349             B_FALSE, B_FALSE));
4350 }
4351 
4352 /*
4353  * ==========================================================================
4354  * Device manipulation
4355  * ==========================================================================
4356  */
4357 
4358 /*
4359  * Add a device to a storage pool.
4360  */
4361 int
4362 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
4363 {
4364         uint64_t txg, id;
4365         int error;
4366         vdev_t *rvd = spa->spa_root_vdev;
4367         vdev_t *vd, *tvd;
4368         nvlist_t **spares, **l2cache;
4369         uint_t nspares, nl2cache;
4370 
4371         ASSERT(spa_writeable(spa));
4372 
4373         txg = spa_vdev_enter(spa);
4374 
4375         if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
4376             VDEV_ALLOC_ADD)) != 0)
4377                 return (spa_vdev_exit(spa, NULL, txg, error));
4378 
4379         spa->spa_pending_vdev = vd;  /* spa_vdev_exit() will clear this */
4380 
4381         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
4382             &nspares) != 0)
4383                 nspares = 0;
4384 
4385         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
4386             &nl2cache) != 0)
4387                 nl2cache = 0;
4388 
4389         if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
4390                 return (spa_vdev_exit(spa, vd, txg, EINVAL));
4391 
4392         if (vd->vdev_children != 0 &&
4393             (error = vdev_create(vd, txg, B_FALSE)) != 0)
4394                 return (spa_vdev_exit(spa, vd, txg, error));
4395 
4396         /*
4397          * We must validate the spares and l2cache devices after checking the
4398          * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
4399          */
4400         if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
4401                 return (spa_vdev_exit(spa, vd, txg, error));
4402 
4403         /*
4404          * Transfer each new top-level vdev from vd to rvd.
4405          */
4406         for (int c = 0; c < vd->vdev_children; c++) {
4407 
4408                 /*
4409                  * Set the vdev id to the first hole, if one exists.
4410                  */
4411                 for (id = 0; id < rvd->vdev_children; id++) {
4412                         if (rvd->vdev_child[id]->vdev_ishole) {
4413                                 vdev_free(rvd->vdev_child[id]);
4414                                 break;
4415                         }
4416                 }
4417                 tvd = vd->vdev_child[c];
4418                 vdev_remove_child(vd, tvd);
4419                 tvd->vdev_id = id;
4420                 vdev_add_child(rvd, tvd);
4421                 vdev_config_dirty(tvd);
4422         }
4423 
4424         if (nspares != 0) {
4425                 spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
4426                     ZPOOL_CONFIG_SPARES);
4427                 spa_load_spares(spa);
4428                 spa->spa_spares.sav_sync = B_TRUE;
4429         }
4430 
4431         if (nl2cache != 0) {
4432                 spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
4433                     ZPOOL_CONFIG_L2CACHE);
4434                 spa_load_l2cache(spa);
4435                 spa->spa_l2cache.sav_sync = B_TRUE;
4436         }
4437 
4438         /*
4439          * We have to be careful when adding new vdevs to an existing pool.
4440          * If other threads start allocating from these vdevs before we
4441          * sync the config cache, and we lose power, then upon reboot we may
4442          * fail to open the pool because there are DVAs that the config cache
4443          * can't translate.  Therefore, we first add the vdevs without
4444          * initializing metaslabs; sync the config cache (via spa_vdev_exit());
4445          * and then let spa_config_update() initialize the new metaslabs.
4446          *
4447          * spa_load() checks for added-but-not-initialized vdevs, so that
4448          * if we lose power at any point in this sequence, the remaining
4449          * steps will be completed the next time we load the pool.
4450          */
4451         (void) spa_vdev_exit(spa, vd, txg, 0);
4452 
4453         mutex_enter(&spa_namespace_lock);
4454         spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4455         spa_event_notify(spa, NULL, ESC_ZFS_VDEV_ADD);
4456         mutex_exit(&spa_namespace_lock);
4457 
4458         return (0);
4459 }
4460 
4461 /*
4462  * Attach a device to a mirror.  The arguments are the path to any device
4463  * in the mirror, and the nvroot for the new device.  If the path specifies
4464  * a device that is not mirrored, we automatically insert the mirror vdev.
4465  *
4466  * If 'replacing' is specified, the new device is intended to replace the
4467  * existing device; in this case the two devices are made into their own
4468  * mirror using the 'replacing' vdev, which is functionally identical to
4469  * the mirror vdev (it actually reuses all the same ops) but has a few
4470  * extra rules: you can't attach to it after it's been created, and upon
4471  * completion of resilvering, the first disk (the one being replaced)
4472  * is automatically detached.
4473  */
4474 int
4475 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
4476 {
4477         uint64_t txg, dtl_max_txg;
4478         vdev_t *rvd = spa->spa_root_vdev;
4479         vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
4480         vdev_ops_t *pvops;
4481         char *oldvdpath, *newvdpath;
4482         int newvd_isspare;
4483         int error;
4484 
4485         ASSERT(spa_writeable(spa));
4486 
4487         txg = spa_vdev_enter(spa);
4488 
4489         oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
4490 
4491         if (oldvd == NULL)
4492                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4493 
4494         if (!oldvd->vdev_ops->vdev_op_leaf)
4495                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4496 
4497         pvd = oldvd->vdev_parent;
4498 
4499         if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
4500             VDEV_ALLOC_ATTACH)) != 0)
4501                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4502 
4503         if (newrootvd->vdev_children != 1)
4504                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4505 
4506         newvd = newrootvd->vdev_child[0];
4507 
4508         if (!newvd->vdev_ops->vdev_op_leaf)
4509                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4510 
4511         if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
4512                 return (spa_vdev_exit(spa, newrootvd, txg, error));
4513 
4514         /*
4515          * Spares can't replace logs
4516          */
4517         if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
4518                 return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4519 
4520         if (!replacing) {
4521                 /*
4522                  * For attach, the only allowable parent is a mirror or the root
4523                  * vdev.
4524                  */
4525                 if (pvd->vdev_ops != &vdev_mirror_ops &&
4526                     pvd->vdev_ops != &vdev_root_ops)
4527                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4528 
4529                 pvops = &vdev_mirror_ops;
4530         } else {
4531                 /*
4532                  * Active hot spares can only be replaced by inactive hot
4533                  * spares.
4534                  */
4535                 if (pvd->vdev_ops == &vdev_spare_ops &&
4536                     oldvd->vdev_isspare &&
4537                     !spa_has_spare(spa, newvd->vdev_guid))
4538                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4539 
4540                 /*
4541                  * If the source is a hot spare, and the parent isn't already a
4542                  * spare, then we want to create a new hot spare.  Otherwise, we
4543                  * want to create a replacing vdev.  The user is not allowed to
4544                  * attach to a spared vdev child unless the 'isspare' state is
4545                  * the same (spare replaces spare, non-spare replaces
4546                  * non-spare).
4547                  */
4548                 if (pvd->vdev_ops == &vdev_replacing_ops &&
4549                     spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
4550                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4551                 } else if (pvd->vdev_ops == &vdev_spare_ops &&
4552                     newvd->vdev_isspare != oldvd->vdev_isspare) {
4553                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4554                 }
4555 
4556                 if (newvd->vdev_isspare)
4557                         pvops = &vdev_spare_ops;
4558                 else
4559                         pvops = &vdev_replacing_ops;
4560         }
4561 
4562         /*
4563          * Make sure the new device is big enough.
4564          */
4565         if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
4566                 return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
4567 
4568         /*
4569          * The new device cannot have a higher alignment requirement
4570          * than the top-level vdev.
4571          */
4572         if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
4573                 return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
4574 
4575         /*
4576          * If this is an in-place replacement, update oldvd's path and devid
4577          * to make it distinguishable from newvd, and unopenable from now on.
4578          */
4579         if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
4580                 spa_strfree(oldvd->vdev_path);
4581                 oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
4582                     KM_SLEEP);
4583                 (void) sprintf(oldvd->vdev_path, "%s/%s",
4584                     newvd->vdev_path, "old");
4585                 if (oldvd->vdev_devid != NULL) {
4586                         spa_strfree(oldvd->vdev_devid);
4587                         oldvd->vdev_devid = NULL;
4588                 }
4589         }
4590 
4591         /* mark the device being resilvered */
4592         newvd->vdev_resilver_txg = txg;
4593 
4594         /*
4595          * If the parent is not a mirror, or if we're replacing, insert the new
4596          * mirror/replacing/spare vdev above oldvd.
4597          */
4598         if (pvd->vdev_ops != pvops)
4599                 pvd = vdev_add_parent(oldvd, pvops);
4600 
4601         ASSERT(pvd->vdev_top->vdev_parent == rvd);
4602         ASSERT(pvd->vdev_ops == pvops);
4603         ASSERT(oldvd->vdev_parent == pvd);
4604 
4605         /*
4606          * Extract the new device from its root and add it to pvd.
4607          */
4608         vdev_remove_child(newrootvd, newvd);
4609         newvd->vdev_id = pvd->vdev_children;
4610         newvd->vdev_crtxg = oldvd->vdev_crtxg;
4611         vdev_add_child(pvd, newvd);
4612 
4613         tvd = newvd->vdev_top;
4614         ASSERT(pvd->vdev_top == tvd);
4615         ASSERT(tvd->vdev_parent == rvd);
4616 
4617         vdev_config_dirty(tvd);
4618 
4619         /*
4620          * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
4621          * for any dmu_sync-ed blocks.  It will propagate upward when
4622          * spa_vdev_exit() calls vdev_dtl_reassess().
4623          */
4624         dtl_max_txg = txg + TXG_CONCURRENT_STATES;
4625 
4626         vdev_dtl_dirty(newvd, DTL_MISSING, TXG_INITIAL,
4627             dtl_max_txg - TXG_INITIAL);
4628 
4629         if (newvd->vdev_isspare) {
4630                 spa_spare_activate(newvd);
4631                 spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
4632         }
4633 
4634         oldvdpath = spa_strdup(oldvd->vdev_path);
4635         newvdpath = spa_strdup(newvd->vdev_path);
4636         newvd_isspare = newvd->vdev_isspare;
4637 
4638         /*
4639          * Mark newvd's DTL dirty in this txg.
4640          */
4641         vdev_dirty(tvd, VDD_DTL, newvd, txg);
4642 
4643         /*
4644          * Schedule the resilver to restart in the future. We do this to
4645          * ensure that dmu_sync-ed blocks have been stitched into the
4646          * respective datasets.
4647          */
4648         dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
4649 
4650         if (spa->spa_bootfs)
4651                 spa_event_notify(spa, newvd, ESC_ZFS_BOOTFS_VDEV_ATTACH);
4652 
4653         spa_event_notify(spa, newvd, ESC_ZFS_VDEV_ATTACH);
4654 
4655         /*
4656          * Commit the config
4657          */
4658         (void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
4659 
4660         spa_history_log_internal(spa, "vdev attach", NULL,
4661             "%s vdev=%s %s vdev=%s",
4662             replacing && newvd_isspare ? "spare in" :
4663             replacing ? "replace" : "attach", newvdpath,
4664             replacing ? "for" : "to", oldvdpath);
4665 
4666         spa_strfree(oldvdpath);
4667         spa_strfree(newvdpath);
4668 
4669         return (0);
4670 }
4671 
4672 /*
4673  * Detach a device from a mirror or replacing vdev.
4674  *
4675  * If 'replace_done' is specified, only detach if the parent
4676  * is a replacing vdev.
4677  */
4678 int
4679 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
4680 {
4681         uint64_t txg;
4682         int error;
4683         vdev_t *rvd = spa->spa_root_vdev;
4684         vdev_t *vd, *pvd, *cvd, *tvd;
4685         boolean_t unspare = B_FALSE;
4686         uint64_t unspare_guid = 0;
4687         char *vdpath;
4688 
4689         ASSERT(spa_writeable(spa));
4690 
4691         txg = spa_vdev_enter(spa);
4692 
4693         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4694 
4695         if (vd == NULL)
4696                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4697 
4698         if (!vd->vdev_ops->vdev_op_leaf)
4699                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4700 
4701         pvd = vd->vdev_parent;
4702 
4703         /*
4704          * If the parent/child relationship is not as expected, don't do it.
4705          * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
4706          * vdev that's replacing B with C.  The user's intent in replacing
4707          * is to go from M(A,B) to M(A,C).  If the user decides to cancel
4708          * the replace by detaching C, the expected behavior is to end up
4709          * M(A,B).  But suppose that right after deciding to detach C,
4710          * the replacement of B completes.  We would have M(A,C), and then
4711          * ask to detach C, which would leave us with just A -- not what
4712          * the user wanted.  To prevent this, we make sure that the
4713          * parent/child relationship hasn't changed -- in this example,
4714          * that C's parent is still the replacing vdev R.
4715          */
4716         if (pvd->vdev_guid != pguid && pguid != 0)
4717                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4718 
4719         /*
4720          * Only 'replacing' or 'spare' vdevs can be replaced.
4721          */
4722         if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
4723             pvd->vdev_ops != &vdev_spare_ops)
4724                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4725 
4726         ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
4727             spa_version(spa) >= SPA_VERSION_SPARES);
4728 
4729         /*
4730          * Only mirror, replacing, and spare vdevs support detach.
4731          */
4732         if (pvd->vdev_ops != &vdev_replacing_ops &&
4733             pvd->vdev_ops != &vdev_mirror_ops &&
4734             pvd->vdev_ops != &vdev_spare_ops)
4735                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4736 
4737         /*
4738          * If this device has the only valid copy of some data,
4739          * we cannot safely detach it.
4740          */
4741         if (vdev_dtl_required(vd))
4742                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4743 
4744         ASSERT(pvd->vdev_children >= 2);
4745 
4746         /*
4747          * If we are detaching the second disk from a replacing vdev, then
4748          * check to see if we changed the original vdev's path to have "/old"
4749          * at the end in spa_vdev_attach().  If so, undo that change now.
4750          */
4751         if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
4752             vd->vdev_path != NULL) {
4753                 size_t len = strlen(vd->vdev_path);
4754 
4755                 for (int c = 0; c < pvd->vdev_children; c++) {
4756                         cvd = pvd->vdev_child[c];
4757 
4758                         if (cvd == vd || cvd->vdev_path == NULL)
4759                                 continue;
4760 
4761                         if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
4762                             strcmp(cvd->vdev_path + len, "/old") == 0) {
4763                                 spa_strfree(cvd->vdev_path);
4764                                 cvd->vdev_path = spa_strdup(vd->vdev_path);
4765                                 break;
4766                         }
4767                 }
4768         }
4769 
4770         /*
4771          * If we are detaching the original disk from a spare, then it implies
4772          * that the spare should become a real disk, and be removed from the
4773          * active spare list for the pool.
4774          */
4775         if (pvd->vdev_ops == &vdev_spare_ops &&
4776             vd->vdev_id == 0 &&
4777             pvd->vdev_child[pvd->vdev_children - 1]->vdev_isspare)
4778                 unspare = B_TRUE;
4779 
4780         /*
4781          * Erase the disk labels so the disk can be used for other things.
4782          * This must be done after all other error cases are handled,
4783          * but before we disembowel vd (so we can still do I/O to it).
4784          * But if we can't do it, don't treat the error as fatal --
4785          * it may be that the unwritability of the disk is the reason
4786          * it's being detached!
4787          */
4788         error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4789 
4790         /*
4791          * Remove vd from its parent and compact the parent's children.
4792          */
4793         vdev_remove_child(pvd, vd);
4794         vdev_compact_children(pvd);
4795 
4796         /*
4797          * Remember one of the remaining children so we can get tvd below.
4798          */
4799         cvd = pvd->vdev_child[pvd->vdev_children - 1];
4800 
4801         /*
4802          * If we need to remove the remaining child from the list of hot spares,
4803          * do it now, marking the vdev as no longer a spare in the process.
4804          * We must do this before vdev_remove_parent(), because that can
4805          * change the GUID if it creates a new toplevel GUID.  For a similar
4806          * reason, we must remove the spare now, in the same txg as the detach;
4807          * otherwise someone could attach a new sibling, change the GUID, and
4808          * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
4809          */
4810         if (unspare) {
4811                 ASSERT(cvd->vdev_isspare);
4812                 spa_spare_remove(cvd);
4813                 unspare_guid = cvd->vdev_guid;
4814                 (void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
4815                 cvd->vdev_unspare = B_TRUE;
4816         }
4817 
4818         /*
4819          * If the parent mirror/replacing vdev only has one child,
4820          * the parent is no longer needed.  Remove it from the tree.
4821          */
4822         if (pvd->vdev_children == 1) {
4823                 if (pvd->vdev_ops == &vdev_spare_ops)
4824                         cvd->vdev_unspare = B_FALSE;
4825                 vdev_remove_parent(cvd);
4826         }
4827 
4828 
4829         /*
4830          * We don't set tvd until now because the parent we just removed
4831          * may have been the previous top-level vdev.
4832          */
4833         tvd = cvd->vdev_top;
4834         ASSERT(tvd->vdev_parent == rvd);
4835 
4836         /*
4837          * Reevaluate the parent vdev state.
4838          */
4839         vdev_propagate_state(cvd);
4840 
4841         /*
4842          * If the 'autoexpand' property is set on the pool then automatically
4843          * try to expand the size of the pool. For example if the device we
4844          * just detached was smaller than the others, it may be possible to
4845          * add metaslabs (i.e. grow the pool). We need to reopen the vdev
4846          * first so that we can obtain the updated sizes of the leaf vdevs.
4847          */
4848         if (spa->spa_autoexpand) {
4849                 vdev_reopen(tvd);
4850                 vdev_expand(tvd, txg);
4851         }
4852 
4853         vdev_config_dirty(tvd);
4854 
4855         /*
4856          * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
4857          * vd->vdev_detached is set and free vd's DTL object in syncing context.
4858          * But first make sure we're not on any *other* txg's DTL list, to
4859          * prevent vd from being accessed after it's freed.
4860          */
4861         vdpath = spa_strdup(vd->vdev_path);
4862         for (int t = 0; t < TXG_SIZE; t++)
4863                 (void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
4864         vd->vdev_detached = B_TRUE;
4865         vdev_dirty(tvd, VDD_DTL, vd, txg);
4866 
4867         spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
4868 
4869         /* hang on to the spa before we release the lock */
4870         spa_open_ref(spa, FTAG);
4871 
4872         error = spa_vdev_exit(spa, vd, txg, 0);
4873 
4874         spa_history_log_internal(spa, "detach", NULL,
4875             "vdev=%s", vdpath);
4876         spa_strfree(vdpath);
4877 
4878         /*
4879          * If this was the removal of the original device in a hot spare vdev,
4880          * then we want to go through and remove the device from the hot spare
4881          * list of every other pool.
4882          */
4883         if (unspare) {
4884                 spa_t *altspa = NULL;
4885 
4886                 mutex_enter(&spa_namespace_lock);
4887                 while ((altspa = spa_next(altspa)) != NULL) {
4888                         if (altspa->spa_state != POOL_STATE_ACTIVE ||
4889                             altspa == spa)
4890                                 continue;
4891 
4892                         spa_open_ref(altspa, FTAG);
4893                         mutex_exit(&spa_namespace_lock);
4894                         (void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
4895                         mutex_enter(&spa_namespace_lock);
4896                         spa_close(altspa, FTAG);
4897                 }
4898                 mutex_exit(&spa_namespace_lock);
4899 
4900                 /* search the rest of the vdevs for spares to remove */
4901                 spa_vdev_resilver_done(spa);
4902         }
4903 
4904         /* all done with the spa; OK to release */
4905         mutex_enter(&spa_namespace_lock);
4906         spa_close(spa, FTAG);
4907         mutex_exit(&spa_namespace_lock);
4908 
4909         return (error);
4910 }
4911 
4912 /*
4913  * Split a set of devices from their mirrors, and create a new pool from them.
4914  */
4915 int
4916 spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
4917     nvlist_t *props, boolean_t exp)
4918 {
4919         int error = 0;
4920         uint64_t txg, *glist;
4921         spa_t *newspa;
4922         uint_t c, children, lastlog;
4923         nvlist_t **child, *nvl, *tmp;
4924         dmu_tx_t *tx;
4925         char *altroot = NULL;
4926         vdev_t *rvd, **vml = NULL;                      /* vdev modify list */
4927         boolean_t activate_slog;
4928 
4929         ASSERT(spa_writeable(spa));
4930 
4931         txg = spa_vdev_enter(spa);
4932 
4933         /* clear the log and flush everything up to now */
4934         activate_slog = spa_passivate_log(spa);
4935         (void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4936         error = spa_offline_log(spa);
4937         txg = spa_vdev_config_enter(spa);
4938 
4939         if (activate_slog)
4940                 spa_activate_log(spa);
4941 
4942         if (error != 0)
4943                 return (spa_vdev_exit(spa, NULL, txg, error));
4944 
4945         /* check new spa name before going any further */
4946         if (spa_lookup(newname) != NULL)
4947                 return (spa_vdev_exit(spa, NULL, txg, EEXIST));
4948 
4949         /*
4950          * scan through all the children to ensure they're all mirrors
4951          */
4952         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
4953             nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
4954             &children) != 0)
4955                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4956 
4957         /* first, check to ensure we've got the right child count */
4958         rvd = spa->spa_root_vdev;
4959         lastlog = 0;
4960         for (c = 0; c < rvd->vdev_children; c++) {
4961                 vdev_t *vd = rvd->vdev_child[c];
4962 
4963                 /* don't count the holes & logs as children */
4964                 if (vd->vdev_islog || vd->vdev_ishole) {
4965                         if (lastlog == 0)
4966                                 lastlog = c;
4967                         continue;
4968                 }
4969 
4970                 lastlog = 0;
4971         }
4972         if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
4973                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4974 
4975         /* next, ensure no spare or cache devices are part of the split */
4976         if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
4977             nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
4978                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4979 
4980         vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
4981         glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
4982 
4983         /* then, loop over each vdev and validate it */
4984         for (c = 0; c < children; c++) {
4985                 uint64_t is_hole = 0;
4986 
4987                 (void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
4988                     &is_hole);
4989 
4990                 if (is_hole != 0) {
4991                         if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
4992                             spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
4993                                 continue;
4994                         } else {
4995                                 error = SET_ERROR(EINVAL);
4996                                 break;
4997                         }
4998                 }
4999 
5000                 /* which disk is going to be split? */
5001                 if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
5002                     &glist[c]) != 0) {
5003                         error = SET_ERROR(EINVAL);
5004                         break;
5005                 }
5006 
5007                 /* look it up in the spa */
5008                 vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
5009                 if (vml[c] == NULL) {
5010                         error = SET_ERROR(ENODEV);
5011                         break;
5012                 }
5013 
5014                 /* make sure there's nothing stopping the split */
5015                 if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
5016                     vml[c]->vdev_islog ||
5017                     vml[c]->vdev_ishole ||
5018                     vml[c]->vdev_isspare ||
5019                     vml[c]->vdev_isl2cache ||
5020                     !vdev_writeable(vml[c]) ||
5021                     vml[c]->vdev_children != 0 ||
5022                     vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
5023                     c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
5024                         error = SET_ERROR(EINVAL);
5025                         break;
5026                 }
5027 
5028                 if (vdev_dtl_required(vml[c])) {
5029                         error = SET_ERROR(EBUSY);
5030                         break;
5031                 }
5032 
5033                 /* we need certain info from the top level */
5034                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
5035                     vml[c]->vdev_top->vdev_ms_array) == 0);
5036                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
5037                     vml[c]->vdev_top->vdev_ms_shift) == 0);
5038                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
5039                     vml[c]->vdev_top->vdev_asize) == 0);
5040                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
5041                     vml[c]->vdev_top->vdev_ashift) == 0);
5042         }
5043 
5044         if (error != 0) {
5045                 kmem_free(vml, children * sizeof (vdev_t *));
5046                 kmem_free(glist, children * sizeof (uint64_t));
5047                 return (spa_vdev_exit(spa, NULL, txg, error));
5048         }
5049 
5050         /* stop writers from using the disks */
5051         for (c = 0; c < children; c++) {
5052                 if (vml[c] != NULL)
5053                         vml[c]->vdev_offline = B_TRUE;
5054         }
5055         vdev_reopen(spa->spa_root_vdev);
5056 
5057         /*
5058          * Temporarily record the splitting vdevs in the spa config.  This
5059          * will disappear once the config is regenerated.
5060          */
5061         VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5062         VERIFY(nvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
5063             glist, children) == 0);
5064         kmem_free(glist, children * sizeof (uint64_t));
5065 
5066         mutex_enter(&spa->spa_props_lock);
5067         VERIFY(nvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT,
5068             nvl) == 0);
5069         mutex_exit(&spa->spa_props_lock);
5070         spa->spa_config_splitting = nvl;
5071         vdev_config_dirty(spa->spa_root_vdev);
5072 
5073         /* configure and create the new pool */
5074         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname) == 0);
5075         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
5076             exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE) == 0);
5077         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
5078             spa_version(spa)) == 0);
5079         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
5080             spa->spa_config_txg) == 0);
5081         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
5082             spa_generate_guid(NULL)) == 0);
5083         (void) nvlist_lookup_string(props,
5084             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
5085 
5086         /* add the new pool to the namespace */
5087         newspa = spa_add(newname, config, altroot);
5088         newspa->spa_config_txg = spa->spa_config_txg;
5089         spa_set_log_state(newspa, SPA_LOG_CLEAR);
5090 
5091         /* release the spa config lock, retaining the namespace lock */
5092         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
5093 
5094         if (zio_injection_enabled)
5095                 zio_handle_panic_injection(spa, FTAG, 1);
5096 
5097         spa_activate(newspa, spa_mode_global);
5098         spa_async_suspend(newspa);
5099 
5100         /* create the new pool from the disks of the original pool */
5101         error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE, B_TRUE);
5102         if (error)
5103                 goto out;
5104 
5105         /* if that worked, generate a real config for the new pool */
5106         if (newspa->spa_root_vdev != NULL) {
5107                 VERIFY(nvlist_alloc(&newspa->spa_config_splitting,
5108                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
5109                 VERIFY(nvlist_add_uint64(newspa->spa_config_splitting,
5110                     ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa)) == 0);
5111                 spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
5112                     B_TRUE));
5113         }
5114 
5115         /* set the props */
5116         if (props != NULL) {
5117                 spa_configfile_set(newspa, props, B_FALSE);
5118                 error = spa_prop_set(newspa, props);
5119                 if (error)
5120                         goto out;
5121         }
5122 
5123         /* flush everything */
5124         txg = spa_vdev_config_enter(newspa);
5125         vdev_config_dirty(newspa->spa_root_vdev);
5126         (void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
5127 
5128         if (zio_injection_enabled)
5129                 zio_handle_panic_injection(spa, FTAG, 2);
5130 
5131         spa_async_resume(newspa);
5132 
5133         /* finally, update the original pool's config */
5134         txg = spa_vdev_config_enter(spa);
5135         tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
5136         error = dmu_tx_assign(tx, TXG_WAIT);
5137         if (error != 0)
5138                 dmu_tx_abort(tx);
5139         for (c = 0; c < children; c++) {
5140                 if (vml[c] != NULL) {
5141                         vdev_split(vml[c]);
5142                         if (error == 0)
5143                                 spa_history_log_internal(spa, "detach", tx,
5144                                     "vdev=%s", vml[c]->vdev_path);
5145                         vdev_free(vml[c]);
5146                 }
5147         }
5148         vdev_config_dirty(spa->spa_root_vdev);
5149         spa->spa_config_splitting = NULL;
5150         nvlist_free(nvl);
5151         if (error == 0)
5152                 dmu_tx_commit(tx);
5153         (void) spa_vdev_exit(spa, NULL, txg, 0);
5154 
5155         if (zio_injection_enabled)
5156                 zio_handle_panic_injection(spa, FTAG, 3);
5157 
5158         /* split is complete; log a history record */
5159         spa_history_log_internal(newspa, "split", NULL,
5160             "from pool %s", spa_name(spa));
5161 
5162         kmem_free(vml, children * sizeof (vdev_t *));
5163 
5164         /* if we're not going to mount the filesystems in userland, export */
5165         if (exp)
5166                 error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
5167                     B_FALSE, B_FALSE);
5168 
5169         return (error);
5170 
5171 out:
5172         spa_unload(newspa);
5173         spa_deactivate(newspa);
5174         spa_remove(newspa);
5175 
5176         txg = spa_vdev_config_enter(spa);
5177 
5178         /* re-online all offlined disks */
5179         for (c = 0; c < children; c++) {
5180                 if (vml[c] != NULL)
5181                         vml[c]->vdev_offline = B_FALSE;
5182         }
5183         vdev_reopen(spa->spa_root_vdev);
5184 
5185         nvlist_free(spa->spa_config_splitting);
5186         spa->spa_config_splitting = NULL;
5187         (void) spa_vdev_exit(spa, NULL, txg, error);
5188 
5189         kmem_free(vml, children * sizeof (vdev_t *));
5190         return (error);
5191 }
5192 
5193 static nvlist_t *
5194 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
5195 {
5196         for (int i = 0; i < count; i++) {
5197                 uint64_t guid;
5198 
5199                 VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
5200                     &guid) == 0);
5201 
5202                 if (guid == target_guid)
5203                         return (nvpp[i]);
5204         }
5205 
5206         return (NULL);
5207 }
5208 
5209 static void
5210 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
5211         nvlist_t *dev_to_remove)
5212 {
5213         nvlist_t **newdev = NULL;
5214 
5215         if (count > 1)
5216                 newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
5217 
5218         for (int i = 0, j = 0; i < count; i++) {
5219                 if (dev[i] == dev_to_remove)
5220                         continue;
5221                 VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
5222         }
5223 
5224         VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
5225         VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
5226 
5227         for (int i = 0; i < count - 1; i++)
5228                 nvlist_free(newdev[i]);
5229 
5230         if (count > 1)
5231                 kmem_free(newdev, (count - 1) * sizeof (void *));
5232 }
5233 
5234 /*
5235  * Evacuate the device.
5236  */
5237 static int
5238 spa_vdev_remove_evacuate(spa_t *spa, vdev_t *vd)
5239 {
5240         uint64_t txg;
5241         int error = 0;
5242 
5243         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5244         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5245         ASSERT(vd == vd->vdev_top);
5246 
5247         /*
5248          * Evacuate the device.  We don't hold the config lock as writer
5249          * since we need to do I/O but we do keep the
5250          * spa_namespace_lock held.  Once this completes the device
5251          * should no longer have any blocks allocated on it.
5252          */
5253         if (vd->vdev_islog) {
5254                 if (vd->vdev_stat.vs_alloc != 0)
5255                         error = spa_offline_log(spa);
5256         } else {
5257                 error = SET_ERROR(ENOTSUP);
5258         }
5259 
5260         if (error)
5261                 return (error);
5262 
5263         /*
5264          * The evacuation succeeded.  Remove any remaining MOS metadata
5265          * associated with this vdev, and wait for these changes to sync.
5266          */
5267         ASSERT0(vd->vdev_stat.vs_alloc);
5268         txg = spa_vdev_config_enter(spa);
5269         vd->vdev_removing = B_TRUE;
5270         vdev_dirty_leaves(vd, VDD_DTL, txg);
5271         vdev_config_dirty(vd);
5272         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
5273 
5274         return (0);
5275 }
5276 
5277 /*
5278  * Complete the removal by cleaning up the namespace.
5279  */
5280 static void
5281 spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
5282 {
5283         vdev_t *rvd = spa->spa_root_vdev;
5284         uint64_t id = vd->vdev_id;
5285         boolean_t last_vdev = (id == (rvd->vdev_children - 1));
5286 
5287         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5288         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
5289         ASSERT(vd == vd->vdev_top);
5290 
5291         /*
5292          * Only remove any devices which are empty.
5293          */
5294         if (vd->vdev_stat.vs_alloc != 0)
5295                 return;
5296 
5297         (void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
5298 
5299         if (list_link_active(&vd->vdev_state_dirty_node))
5300                 vdev_state_clean(vd);
5301         if (list_link_active(&vd->vdev_config_dirty_node))
5302                 vdev_config_clean(vd);
5303 
5304         vdev_free(vd);
5305 
5306         if (last_vdev) {
5307                 vdev_compact_children(rvd);
5308         } else {
5309                 vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops);
5310                 vdev_add_child(rvd, vd);
5311         }
5312         vdev_config_dirty(rvd);
5313 
5314         /*
5315          * Reassess the health of our root vdev.
5316          */
5317         vdev_reopen(rvd);
5318 }
5319 
5320 /*
5321  * Remove a device from the pool -
5322  *
5323  * Removing a device from the vdev namespace requires several steps
5324  * and can take a significant amount of time.  As a result we use
5325  * the spa_vdev_config_[enter/exit] functions which allow us to
5326  * grab and release the spa_config_lock while still holding the namespace
5327  * lock.  During each step the configuration is synced out.
5328  *
5329  * Currently, this supports removing only hot spares, slogs, and level 2 ARC
5330  * devices.
5331  */
5332 int
5333 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
5334 {
5335         vdev_t *vd;
5336         metaslab_group_t *mg;
5337         nvlist_t **spares, **l2cache, *nv;
5338         uint64_t txg = 0;
5339         uint_t nspares, nl2cache;
5340         int error = 0;
5341         boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
5342 
5343         ASSERT(spa_writeable(spa));
5344 
5345         if (!locked)
5346                 txg = spa_vdev_enter(spa);
5347 
5348         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
5349 
5350         if (spa->spa_spares.sav_vdevs != NULL &&
5351             nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
5352             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
5353             (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
5354                 /*
5355                  * Only remove the hot spare if it's not currently in use
5356                  * in this pool.
5357                  */
5358                 if (vd == NULL || unspare) {
5359                         spa_vdev_remove_aux(spa->spa_spares.sav_config,
5360                             ZPOOL_CONFIG_SPARES, spares, nspares, nv);
5361                         spa_load_spares(spa);
5362                         spa->spa_spares.sav_sync = B_TRUE;
5363                 } else {
5364                         error = SET_ERROR(EBUSY);
5365                 }
5366         } else if (spa->spa_l2cache.sav_vdevs != NULL &&
5367             nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
5368             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
5369             (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
5370                 /*
5371                  * Cache devices can always be removed.
5372                  */
5373                 spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
5374                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
5375                 spa_load_l2cache(spa);
5376                 spa->spa_l2cache.sav_sync = B_TRUE;
5377         } else if (vd != NULL && vd->vdev_islog) {
5378                 ASSERT(!locked);
5379                 ASSERT(vd == vd->vdev_top);
5380 
5381                 mg = vd->vdev_mg;
5382 
5383                 /*
5384                  * Stop allocating from this vdev.
5385                  */
5386                 metaslab_group_passivate(mg);
5387 
5388                 /*
5389                  * Wait for the youngest allocations and frees to sync,
5390                  * and then wait for the deferral of those frees to finish.
5391                  */
5392                 spa_vdev_config_exit(spa, NULL,
5393                     txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
5394 
5395                 /*
5396                  * Attempt to evacuate the vdev.
5397                  */
5398                 error = spa_vdev_remove_evacuate(spa, vd);
5399 
5400                 txg = spa_vdev_config_enter(spa);
5401 
5402                 /*
5403                  * If we couldn't evacuate the vdev, unwind.
5404                  */
5405                 if (error) {
5406                         metaslab_group_activate(mg);
5407                         return (spa_vdev_exit(spa, NULL, txg, error));
5408                 }
5409 
5410                 /*
5411                  * Clean up the vdev namespace.
5412                  */
5413                 spa_vdev_remove_from_namespace(spa, vd);
5414 
5415         } else if (vd != NULL) {
5416                 /*
5417                  * Normal vdevs cannot be removed (yet).
5418                  */
5419                 error = SET_ERROR(ENOTSUP);
5420         } else {
5421                 /*
5422                  * There is no vdev of any kind with the specified guid.
5423                  */
5424                 error = SET_ERROR(ENOENT);
5425         }
5426 
5427         if (!locked)
5428                 return (spa_vdev_exit(spa, NULL, txg, error));
5429 
5430         return (error);
5431 }
5432 
5433 /*
5434  * Find any device that's done replacing, or a vdev marked 'unspare' that's
5435  * currently spared, so we can detach it.
5436  */
5437 static vdev_t *
5438 spa_vdev_resilver_done_hunt(vdev_t *vd)
5439 {
5440         vdev_t *newvd, *oldvd;
5441 
5442         for (int c = 0; c < vd->vdev_children; c++) {
5443                 oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
5444                 if (oldvd != NULL)
5445                         return (oldvd);
5446         }
5447 
5448         /*
5449          * Check for a completed replacement.  We always consider the first
5450          * vdev in the list to be the oldest vdev, and the last one to be
5451          * the newest (see spa_vdev_attach() for how that works).  In
5452          * the case where the newest vdev is faulted, we will not automatically
5453          * remove it after a resilver completes.  This is OK as it will require
5454          * user intervention to determine which disk the admin wishes to keep.
5455          */
5456         if (vd->vdev_ops == &vdev_replacing_ops) {
5457                 ASSERT(vd->vdev_children > 1);
5458 
5459                 newvd = vd->vdev_child[vd->vdev_children - 1];
5460                 oldvd = vd->vdev_child[0];
5461 
5462                 if (vdev_dtl_empty(newvd, DTL_MISSING) &&
5463                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5464                     !vdev_dtl_required(oldvd))
5465                         return (oldvd);
5466         }
5467 
5468         /*
5469          * Check for a completed resilver with the 'unspare' flag set.
5470          */
5471         if (vd->vdev_ops == &vdev_spare_ops) {
5472                 vdev_t *first = vd->vdev_child[0];
5473                 vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
5474 
5475                 if (last->vdev_unspare) {
5476                         oldvd = first;
5477                         newvd = last;
5478                 } else if (first->vdev_unspare) {
5479                         oldvd = last;
5480                         newvd = first;
5481                 } else {
5482                         oldvd = NULL;
5483                 }
5484 
5485                 if (oldvd != NULL &&
5486                     vdev_dtl_empty(newvd, DTL_MISSING) &&
5487                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5488                     !vdev_dtl_required(oldvd))
5489                         return (oldvd);
5490 
5491                 /*
5492                  * If there are more than two spares attached to a disk,
5493                  * and those spares are not required, then we want to
5494                  * attempt to free them up now so that they can be used
5495                  * by other pools.  Once we're back down to a single
5496                  * disk+spare, we stop removing them.
5497                  */
5498                 if (vd->vdev_children > 2) {
5499                         newvd = vd->vdev_child[1];
5500 
5501                         if (newvd->vdev_isspare && last->vdev_isspare &&
5502                             vdev_dtl_empty(last, DTL_MISSING) &&
5503                             vdev_dtl_empty(last, DTL_OUTAGE) &&
5504                             !vdev_dtl_required(newvd))
5505                                 return (newvd);
5506                 }
5507         }
5508 
5509         return (NULL);
5510 }
5511 
5512 static void
5513 spa_vdev_resilver_done(spa_t *spa)
5514 {
5515         vdev_t *vd, *pvd, *ppvd;
5516         uint64_t guid, sguid, pguid, ppguid;
5517 
5518         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5519 
5520         while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
5521                 pvd = vd->vdev_parent;
5522                 ppvd = pvd->vdev_parent;
5523                 guid = vd->vdev_guid;
5524                 pguid = pvd->vdev_guid;
5525                 ppguid = ppvd->vdev_guid;
5526                 sguid = 0;
5527                 /*
5528                  * If we have just finished replacing a hot spared device, then
5529                  * we need to detach the parent's first child (the original hot
5530                  * spare) as well.
5531                  */
5532                 if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
5533                     ppvd->vdev_children == 2) {
5534                         ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
5535                         sguid = ppvd->vdev_child[1]->vdev_guid;
5536                 }
5537                 ASSERT(vd->vdev_resilver_txg == 0 || !vdev_dtl_required(vd));
5538 
5539                 spa_config_exit(spa, SCL_ALL, FTAG);
5540                 if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
5541                         return;
5542                 if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
5543                         return;
5544                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5545         }
5546 
5547         spa_config_exit(spa, SCL_ALL, FTAG);
5548 }
5549 
5550 /*
5551  * Update the stored path or FRU for this vdev.
5552  */
5553 int
5554 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
5555     boolean_t ispath)
5556 {
5557         vdev_t *vd;
5558         boolean_t sync = B_FALSE;
5559 
5560         ASSERT(spa_writeable(spa));
5561 
5562         spa_vdev_state_enter(spa, SCL_ALL);
5563 
5564         if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
5565                 return (spa_vdev_state_exit(spa, NULL, ENOENT));
5566 
5567         if (!vd->vdev_ops->vdev_op_leaf)
5568                 return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
5569 
5570         if (ispath) {
5571                 if (strcmp(value, vd->vdev_path) != 0) {
5572                         spa_strfree(vd->vdev_path);
5573                         vd->vdev_path = spa_strdup(value);
5574                         sync = B_TRUE;
5575                 }
5576         } else {
5577                 if (vd->vdev_fru == NULL) {
5578                         vd->vdev_fru = spa_strdup(value);
5579                         sync = B_TRUE;
5580                 } else if (strcmp(value, vd->vdev_fru) != 0) {
5581                         spa_strfree(vd->vdev_fru);
5582                         vd->vdev_fru = spa_strdup(value);
5583                         sync = B_TRUE;
5584                 }
5585         }
5586 
5587         return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
5588 }
5589 
5590 int
5591 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
5592 {
5593         return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
5594 }
5595 
5596 int
5597 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
5598 {
5599         return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
5600 }
5601 
5602 /*
5603  * ==========================================================================
5604  * SPA Scanning
5605  * ==========================================================================
5606  */
5607 
5608 int
5609 spa_scan_stop(spa_t *spa)
5610 {
5611         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5612         if (dsl_scan_resilvering(spa->spa_dsl_pool))
5613                 return (SET_ERROR(EBUSY));
5614         return (dsl_scan_cancel(spa->spa_dsl_pool));
5615 }
5616 
5617 int
5618 spa_scan(spa_t *spa, pool_scan_func_t func)
5619 {
5620         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5621 
5622         if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
5623                 return (SET_ERROR(ENOTSUP));
5624 
5625         /*
5626          * If a resilver was requested, but there is no DTL on a
5627          * writeable leaf device, we have nothing to do.
5628          */
5629         if (func == POOL_SCAN_RESILVER &&
5630             !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
5631                 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
5632                 return (0);
5633         }
5634 
5635         return (dsl_scan(spa->spa_dsl_pool, func));
5636 }
5637 
5638 /*
5639  * ==========================================================================
5640  * SPA async task processing
5641  * ==========================================================================
5642  */
5643 
5644 static void
5645 spa_async_remove(spa_t *spa, vdev_t *vd)
5646 {
5647         if (vd->vdev_remove_wanted) {
5648                 vd->vdev_remove_wanted = B_FALSE;
5649                 vd->vdev_delayed_close = B_FALSE;
5650                 vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
5651 
5652                 /*
5653                  * We want to clear the stats, but we don't want to do a full
5654                  * vdev_clear() as that will cause us to throw away
5655                  * degraded/faulted state as well as attempt to reopen the
5656                  * device, all of which is a waste.
5657                  */
5658                 vd->vdev_stat.vs_read_errors = 0;
5659                 vd->vdev_stat.vs_write_errors = 0;
5660                 vd->vdev_stat.vs_checksum_errors = 0;
5661 
5662                 vdev_state_dirty(vd->vdev_top);
5663         }
5664 
5665         for (int c = 0; c < vd->vdev_children; c++)
5666                 spa_async_remove(spa, vd->vdev_child[c]);
5667 }
5668 
5669 static void
5670 spa_async_probe(spa_t *spa, vdev_t *vd)
5671 {
5672         if (vd->vdev_probe_wanted) {
5673                 vd->vdev_probe_wanted = B_FALSE;
5674                 vdev_reopen(vd);        /* vdev_open() does the actual probe */
5675         }
5676 
5677         for (int c = 0; c < vd->vdev_children; c++)
5678                 spa_async_probe(spa, vd->vdev_child[c]);
5679 }
5680 
5681 static void
5682 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
5683 {
5684         sysevent_id_t eid;
5685         nvlist_t *attr;
5686         char *physpath;
5687 
5688         if (!spa->spa_autoexpand)
5689                 return;
5690 
5691         for (int c = 0; c < vd->vdev_children; c++) {
5692                 vdev_t *cvd = vd->vdev_child[c];
5693                 spa_async_autoexpand(spa, cvd);
5694         }
5695 
5696         if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
5697                 return;
5698 
5699         physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
5700         (void) snprintf(physpath, MAXPATHLEN, "/devices%s", vd->vdev_physpath);
5701 
5702         VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5703         VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
5704 
5705         (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
5706             ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
5707 
5708         nvlist_free(attr);
5709         kmem_free(physpath, MAXPATHLEN);
5710 }
5711 
5712 static void
5713 spa_async_thread(spa_t *spa)
5714 {
5715         int tasks;
5716 
5717         ASSERT(spa->spa_sync_on);
5718 
5719         mutex_enter(&spa->spa_async_lock);
5720         tasks = spa->spa_async_tasks;
5721         spa->spa_async_tasks = 0;
5722         mutex_exit(&spa->spa_async_lock);
5723 
5724         /*
5725          * See if the config needs to be updated.
5726          */
5727         if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
5728                 uint64_t old_space, new_space;
5729 
5730                 mutex_enter(&spa_namespace_lock);
5731                 old_space = metaslab_class_get_space(spa_normal_class(spa));
5732                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
5733                 new_space = metaslab_class_get_space(spa_normal_class(spa));
5734                 mutex_exit(&spa_namespace_lock);
5735 
5736                 /*
5737                  * If the pool grew as a result of the config update,
5738                  * then log an internal history event.
5739                  */
5740                 if (new_space != old_space) {
5741                         spa_history_log_internal(spa, "vdev online", NULL,
5742                             "pool '%s' size: %llu(+%llu)",
5743                             spa_name(spa), new_space, new_space - old_space);
5744                 }
5745         }
5746 
5747         /*
5748          * See if any devices need to be marked REMOVED.
5749          */
5750         if (tasks & SPA_ASYNC_REMOVE) {
5751                 spa_vdev_state_enter(spa, SCL_NONE);
5752                 spa_async_remove(spa, spa->spa_root_vdev);
5753                 for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
5754                         spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
5755                 for (int i = 0; i < spa->spa_spares.sav_count; i++)
5756                         spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
5757                 (void) spa_vdev_state_exit(spa, NULL, 0);
5758         }
5759 
5760         if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
5761                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5762                 spa_async_autoexpand(spa, spa->spa_root_vdev);
5763                 spa_config_exit(spa, SCL_CONFIG, FTAG);
5764         }
5765 
5766         /*
5767          * See if any devices need to be probed.
5768          */
5769         if (tasks & SPA_ASYNC_PROBE) {
5770                 spa_vdev_state_enter(spa, SCL_NONE);
5771                 spa_async_probe(spa, spa->spa_root_vdev);
5772                 (void) spa_vdev_state_exit(spa, NULL, 0);
5773         }
5774 
5775         /*
5776          * If any devices are done replacing, detach them.
5777          */
5778         if (tasks & SPA_ASYNC_RESILVER_DONE)
5779                 spa_vdev_resilver_done(spa);
5780 
5781         /*
5782          * Kick off a resilver.
5783          */
5784         if (tasks & SPA_ASYNC_RESILVER)
5785                 dsl_resilver_restart(spa->spa_dsl_pool, 0);
5786 
5787         /*
5788          * Let the world know that we're done.
5789          */
5790         mutex_enter(&spa->spa_async_lock);
5791         spa->spa_async_thread = NULL;
5792         cv_broadcast(&spa->spa_async_cv);
5793         mutex_exit(&spa->spa_async_lock);
5794         thread_exit();
5795 }
5796 
5797 void
5798 spa_async_suspend(spa_t *spa)
5799 {
5800         mutex_enter(&spa->spa_async_lock);
5801         spa->spa_async_suspended++;
5802         while (spa->spa_async_thread != NULL)
5803                 cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
5804         mutex_exit(&spa->spa_async_lock);
5805 }
5806 
5807 void
5808 spa_async_resume(spa_t *spa)
5809 {
5810         mutex_enter(&spa->spa_async_lock);
5811         ASSERT(spa->spa_async_suspended != 0);
5812         spa->spa_async_suspended--;
5813         mutex_exit(&spa->spa_async_lock);
5814 }
5815 
5816 static boolean_t
5817 spa_async_tasks_pending(spa_t *spa)
5818 {
5819         uint_t non_config_tasks;
5820         uint_t config_task;
5821         boolean_t config_task_suspended;
5822 
5823         non_config_tasks = spa->spa_async_tasks & ~SPA_ASYNC_CONFIG_UPDATE;
5824         config_task = spa->spa_async_tasks & SPA_ASYNC_CONFIG_UPDATE;
5825         if (spa->spa_ccw_fail_time == 0) {
5826                 config_task_suspended = B_FALSE;
5827         } else {
5828                 config_task_suspended =
5829                     (gethrtime() - spa->spa_ccw_fail_time) <
5830                     (zfs_ccw_retry_interval * NANOSEC);
5831         }
5832 
5833         return (non_config_tasks || (config_task && !config_task_suspended));
5834 }
5835 
5836 static void
5837 spa_async_dispatch(spa_t *spa)
5838 {
5839         mutex_enter(&spa->spa_async_lock);
5840         if (spa_async_tasks_pending(spa) &&
5841             !spa->spa_async_suspended &&
5842             spa->spa_async_thread == NULL &&
5843             rootdir != NULL)
5844                 spa->spa_async_thread = thread_create(NULL, 0,
5845                     spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
5846         mutex_exit(&spa->spa_async_lock);
5847 }
5848 
5849 void
5850 spa_async_request(spa_t *spa, int task)
5851 {
5852         zfs_dbgmsg("spa=%s async request task=%u", spa->spa_name, task);
5853         mutex_enter(&spa->spa_async_lock);
5854         spa->spa_async_tasks |= task;
5855         mutex_exit(&spa->spa_async_lock);
5856 }
5857 
5858 /*
5859  * ==========================================================================
5860  * SPA syncing routines
5861  * ==========================================================================
5862  */
5863 
5864 static int
5865 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5866 {
5867         bpobj_t *bpo = arg;
5868         bpobj_enqueue(bpo, bp, tx);
5869         return (0);
5870 }
5871 
5872 static int
5873 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5874 {
5875         zio_t *zio = arg;
5876 
5877         zio_nowait(zio_free_sync(zio, zio->io_spa, dmu_tx_get_txg(tx), bp,
5878             zio->io_flags));
5879         return (0);
5880 }
5881 
5882 /*
5883  * Note: this simple function is not inlined to make it easier to dtrace the
5884  * amount of time spent syncing frees.
5885  */
5886 static void
5887 spa_sync_frees(spa_t *spa, bplist_t *bpl, dmu_tx_t *tx)
5888 {
5889         zio_t *zio = zio_root(spa, NULL, NULL, 0);
5890         bplist_iterate(bpl, spa_free_sync_cb, zio, tx);
5891         VERIFY(zio_wait(zio) == 0);
5892 }
5893 
5894 /*
5895  * Note: this simple function is not inlined to make it easier to dtrace the
5896  * amount of time spent syncing deferred frees.
5897  */
5898 static void
5899 spa_sync_deferred_frees(spa_t *spa, dmu_tx_t *tx)
5900 {
5901         zio_t *zio = zio_root(spa, NULL, NULL, 0);
5902         VERIFY3U(bpobj_iterate(&spa->spa_deferred_bpobj,
5903             spa_free_sync_cb, zio, tx), ==, 0);
5904         VERIFY0(zio_wait(zio));
5905 }
5906 
5907 
5908 static void
5909 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
5910 {
5911         char *packed = NULL;
5912         size_t bufsize;
5913         size_t nvsize = 0;
5914         dmu_buf_t *db;
5915 
5916         VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
5917 
5918         /*
5919          * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
5920          * information.  This avoids the dmu_buf_will_dirty() path and
5921          * saves us a pre-read to get data we don't actually care about.
5922          */
5923         bufsize = P2ROUNDUP((uint64_t)nvsize, SPA_CONFIG_BLOCKSIZE);
5924         packed = kmem_alloc(bufsize, KM_SLEEP);
5925 
5926         VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
5927             KM_SLEEP) == 0);
5928         bzero(packed + nvsize, bufsize - nvsize);
5929 
5930         dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
5931 
5932         kmem_free(packed, bufsize);
5933 
5934         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
5935         dmu_buf_will_dirty(db, tx);
5936         *(uint64_t *)db->db_data = nvsize;
5937         dmu_buf_rele(db, FTAG);
5938 }
5939 
5940 static void
5941 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
5942     const char *config, const char *entry)
5943 {
5944         nvlist_t *nvroot;
5945         nvlist_t **list;
5946         int i;
5947 
5948         if (!sav->sav_sync)
5949                 return;
5950 
5951         /*
5952          * Update the MOS nvlist describing the list of available devices.
5953          * spa_validate_aux() will have already made sure this nvlist is
5954          * valid and the vdevs are labeled appropriately.
5955          */
5956         if (sav->sav_object == 0) {
5957                 sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
5958                     DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
5959                     sizeof (uint64_t), tx);
5960                 VERIFY(zap_update(spa->spa_meta_objset,
5961                     DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
5962                     &sav->sav_object, tx) == 0);
5963         }
5964 
5965         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5966         if (sav->sav_count == 0) {
5967                 VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
5968         } else {
5969                 list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
5970                 for (i = 0; i < sav->sav_count; i++)
5971                         list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
5972                             B_FALSE, VDEV_CONFIG_L2CACHE);
5973                 VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
5974                     sav->sav_count) == 0);
5975                 for (i = 0; i < sav->sav_count; i++)
5976                         nvlist_free(list[i]);
5977                 kmem_free(list, sav->sav_count * sizeof (void *));
5978         }
5979 
5980         spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
5981         nvlist_free(nvroot);
5982 
5983         sav->sav_sync = B_FALSE;
5984 }
5985 
5986 static void
5987 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
5988 {
5989         nvlist_t *config;
5990 
5991         if (list_is_empty(&spa->spa_config_dirty_list))
5992                 return;
5993 
5994         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5995 
5996         config = spa_config_generate(spa, spa->spa_root_vdev,
5997             dmu_tx_get_txg(tx), B_FALSE);
5998 
5999         /*
6000          * If we're upgrading the spa version then make sure that
6001          * the config object gets updated with the correct version.
6002          */
6003         if (spa->spa_ubsync.ub_version < spa->spa_uberblock.ub_version)
6004                 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
6005                     spa->spa_uberblock.ub_version);
6006 
6007         spa_config_exit(spa, SCL_STATE, FTAG);
6008 
6009         if (spa->spa_config_syncing)
6010                 nvlist_free(spa->spa_config_syncing);
6011         spa->spa_config_syncing = config;
6012 
6013         spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
6014 }
6015 
6016 static void
6017 spa_sync_version(void *arg, dmu_tx_t *tx)
6018 {
6019         uint64_t *versionp = arg;
6020         uint64_t version = *versionp;
6021         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
6022 
6023         /*
6024          * Setting the version is special cased when first creating the pool.
6025          */
6026         ASSERT(tx->tx_txg != TXG_INITIAL);
6027 
6028         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
6029         ASSERT(version >= spa_version(spa));
6030 
6031         spa->spa_uberblock.ub_version = version;
6032         vdev_config_dirty(spa->spa_root_vdev);
6033         spa_history_log_internal(spa, "set", tx, "version=%lld", version);
6034 }
6035 
6036 /*
6037  * Set zpool properties.
6038  */
6039 static void
6040 spa_sync_props(void *arg, dmu_tx_t *tx)
6041 {
6042         nvlist_t *nvp = arg;
6043         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
6044         objset_t *mos = spa->spa_meta_objset;
6045         nvpair_t *elem = NULL;
6046 
6047         mutex_enter(&spa->spa_props_lock);
6048 
6049         while ((elem = nvlist_next_nvpair(nvp, elem))) {
6050                 uint64_t intval;
6051                 char *strval, *fname;
6052                 zpool_prop_t prop;
6053                 const char *propname;
6054                 zprop_type_t proptype;
6055                 spa_feature_t fid;
6056 
6057                 switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
6058                 case ZPROP_INVAL:
6059                         /*
6060                          * We checked this earlier in spa_prop_validate().
6061                          */
6062                         ASSERT(zpool_prop_feature(nvpair_name(elem)));
6063 
6064                         fname = strchr(nvpair_name(elem), '@') + 1;
6065                         VERIFY0(zfeature_lookup_name(fname, &fid));
6066 
6067                         spa_feature_enable(spa, fid, tx);
6068                         spa_history_log_internal(spa, "set", tx,
6069                             "%s=enabled", nvpair_name(elem));
6070                         break;
6071 
6072                 case ZPOOL_PROP_VERSION:
6073                         intval = fnvpair_value_uint64(elem);
6074                         /*
6075                          * The version is synced seperatly before other
6076                          * properties and should be correct by now.
6077                          */
6078                         ASSERT3U(spa_version(spa), >=, intval);
6079                         break;
6080 
6081                 case ZPOOL_PROP_ALTROOT:
6082                         /*
6083                          * 'altroot' is a non-persistent property. It should
6084                          * have been set temporarily at creation or import time.
6085                          */
6086                         ASSERT(spa->spa_root != NULL);
6087                         break;
6088 
6089                 case ZPOOL_PROP_READONLY:
6090                 case ZPOOL_PROP_CACHEFILE:
6091                         /*
6092                          * 'readonly' and 'cachefile' are also non-persisitent
6093                          * properties.
6094                          */
6095                         break;
6096                 case ZPOOL_PROP_COMMENT:
6097                         strval = fnvpair_value_string(elem);
6098                         if (spa->spa_comment != NULL)
6099                                 spa_strfree(spa->spa_comment);
6100                         spa->spa_comment = spa_strdup(strval);
6101                         /*
6102                          * We need to dirty the configuration on all the vdevs
6103                          * so that their labels get updated.  It's unnecessary
6104                          * to do this for pool creation since the vdev's
6105                          * configuratoin has already been dirtied.
6106                          */
6107                         if (tx->tx_txg != TXG_INITIAL)
6108                                 vdev_config_dirty(spa->spa_root_vdev);
6109                         spa_history_log_internal(spa, "set", tx,
6110                             "%s=%s", nvpair_name(elem), strval);
6111                         break;
6112                 default:
6113                         /*
6114                          * Set pool property values in the poolprops mos object.
6115                          */
6116                         if (spa->spa_pool_props_object == 0) {
6117                                 spa->spa_pool_props_object =
6118                                     zap_create_link(mos, DMU_OT_POOL_PROPS,
6119                                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
6120                                     tx);
6121                         }
6122 
6123                         /* normalize the property name */
6124                         propname = zpool_prop_to_name(prop);
6125                         proptype = zpool_prop_get_type(prop);
6126 
6127                         if (nvpair_type(elem) == DATA_TYPE_STRING) {
6128                                 ASSERT(proptype == PROP_TYPE_STRING);
6129                                 strval = fnvpair_value_string(elem);
6130                                 VERIFY0(zap_update(mos,
6131                                     spa->spa_pool_props_object, propname,
6132                                     1, strlen(strval) + 1, strval, tx));
6133                                 spa_history_log_internal(spa, "set", tx,
6134                                     "%s=%s", nvpair_name(elem), strval);
6135                         } else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
6136                                 intval = fnvpair_value_uint64(elem);
6137 
6138                                 if (proptype == PROP_TYPE_INDEX) {
6139                                         const char *unused;
6140                                         VERIFY0(zpool_prop_index_to_string(
6141                                             prop, intval, &unused));
6142                                 }
6143                                 VERIFY0(zap_update(mos,
6144                                     spa->spa_pool_props_object, propname,
6145                                     8, 1, &intval, tx));
6146                                 spa_history_log_internal(spa, "set", tx,
6147                                     "%s=%lld", nvpair_name(elem), intval);
6148                         } else {
6149                                 ASSERT(0); /* not allowed */
6150                         }
6151 
6152                         switch (prop) {
6153                         case ZPOOL_PROP_DELEGATION:
6154                                 spa->spa_delegation = intval;
6155                                 break;
6156                         case ZPOOL_PROP_BOOTFS:
6157                                 spa->spa_bootfs = intval;
6158                                 break;
6159                         case ZPOOL_PROP_FAILUREMODE:
6160                                 spa->spa_failmode = intval;
6161                                 break;
6162                         case ZPOOL_PROP_AUTOEXPAND:
6163                                 spa->spa_autoexpand = intval;
6164                                 if (tx->tx_txg != TXG_INITIAL)
6165                                         spa_async_request(spa,
6166                                             SPA_ASYNC_AUTOEXPAND);
6167                                 break;
6168                         case ZPOOL_PROP_DEDUPDITTO:
6169                                 spa->spa_dedup_ditto = intval;
6170                                 break;
6171                         default:
6172                                 break;
6173                         }
6174                 }
6175 
6176         }
6177 
6178         mutex_exit(&spa->spa_props_lock);
6179 }
6180 
6181 /*
6182  * Perform one-time upgrade on-disk changes.  spa_version() does not
6183  * reflect the new version this txg, so there must be no changes this
6184  * txg to anything that the upgrade code depends on after it executes.
6185  * Therefore this must be called after dsl_pool_sync() does the sync
6186  * tasks.
6187  */
6188 static void
6189 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
6190 {
6191         dsl_pool_t *dp = spa->spa_dsl_pool;
6192 
6193         ASSERT(spa->spa_sync_pass == 1);
6194 
6195         rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
6196 
6197         if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
6198             spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
6199                 dsl_pool_create_origin(dp, tx);
6200 
6201                 /* Keeping the origin open increases spa_minref */
6202                 spa->spa_minref += 3;
6203         }
6204 
6205         if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
6206             spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
6207                 dsl_pool_upgrade_clones(dp, tx);
6208         }
6209 
6210         if (spa->spa_ubsync.ub_version < SPA_VERSION_DIR_CLONES &&
6211             spa->spa_uberblock.ub_version >= SPA_VERSION_DIR_CLONES) {
6212                 dsl_pool_upgrade_dir_clones(dp, tx);
6213 
6214                 /* Keeping the freedir open increases spa_minref */
6215                 spa->spa_minref += 3;
6216         }
6217 
6218         if (spa->spa_ubsync.ub_version < SPA_VERSION_FEATURES &&
6219             spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
6220                 spa_feature_create_zap_objects(spa, tx);
6221         }
6222 
6223         /*
6224          * LZ4_COMPRESS feature's behaviour was changed to activate_on_enable
6225          * when possibility to use lz4 compression for metadata was added
6226          * Old pools that have this feature enabled must be upgraded to have
6227          * this feature active
6228          */
6229         if (spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
6230                 boolean_t lz4_en = spa_feature_is_enabled(spa,
6231                     SPA_FEATURE_LZ4_COMPRESS);
6232                 boolean_t lz4_ac = spa_feature_is_active(spa,
6233                     SPA_FEATURE_LZ4_COMPRESS);
6234 
6235                 if (lz4_en && !lz4_ac)
6236                         spa_feature_incr(spa, SPA_FEATURE_LZ4_COMPRESS, tx);
6237         }
6238 
6239         /*
6240          * If we haven't written the salt, do so now.  Note that the
6241          * feature may not be activated yet, but that's fine since
6242          * the presence of this ZAP entry is backwards compatible.
6243          */
6244         if (zap_contains(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
6245             DMU_POOL_CHECKSUM_SALT) == ENOENT) {
6246                 VERIFY0(zap_add(spa->spa_meta_objset,
6247                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CHECKSUM_SALT, 1,
6248                     sizeof (spa->spa_cksum_salt.zcs_bytes),
6249                     spa->spa_cksum_salt.zcs_bytes, tx));
6250         }
6251 
6252         rrw_exit(&dp->dp_config_rwlock, FTAG);
6253 }
6254 
6255 /*
6256  * Sync the specified transaction group.  New blocks may be dirtied as
6257  * part of the process, so we iterate until it converges.
6258  */
6259 void
6260 spa_sync(spa_t *spa, uint64_t txg)
6261 {
6262         dsl_pool_t *dp = spa->spa_dsl_pool;
6263         objset_t *mos = spa->spa_meta_objset;
6264         bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
6265         vdev_t *rvd = spa->spa_root_vdev;
6266         vdev_t *vd;
6267         dmu_tx_t *tx;
6268         int error;
6269 
6270         VERIFY(spa_writeable(spa));
6271 
6272         /*
6273          * Lock out configuration changes.
6274          */
6275         spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
6276 
6277         spa->spa_syncing_txg = txg;
6278         spa->spa_sync_pass = 0;
6279 
6280         /*
6281          * If there are any pending vdev state changes, convert them
6282          * into config changes that go out with this transaction group.
6283          */
6284         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6285         while (list_head(&spa->spa_state_dirty_list) != NULL) {
6286                 /*
6287                  * We need the write lock here because, for aux vdevs,
6288                  * calling vdev_config_dirty() modifies sav_config.
6289                  * This is ugly and will become unnecessary when we
6290                  * eliminate the aux vdev wart by integrating all vdevs
6291                  * into the root vdev tree.
6292                  */
6293                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6294                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
6295                 while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
6296                         vdev_state_clean(vd);
6297                         vdev_config_dirty(vd);
6298                 }
6299                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6300                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
6301         }
6302         spa_config_exit(spa, SCL_STATE, FTAG);
6303 
6304         tx = dmu_tx_create_assigned(dp, txg);
6305 
6306         spa->spa_sync_starttime = gethrtime();
6307         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid,
6308             spa->spa_sync_starttime + spa->spa_deadman_synctime));
6309 
6310         /*
6311          * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
6312          * set spa_deflate if we have no raid-z vdevs.
6313          */
6314         if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
6315             spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
6316                 int i;
6317 
6318                 for (i = 0; i < rvd->vdev_children; i++) {
6319                         vd = rvd->vdev_child[i];
6320                         if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
6321                                 break;
6322                 }
6323                 if (i == rvd->vdev_children) {
6324                         spa->spa_deflate = TRUE;
6325                         VERIFY(0 == zap_add(spa->spa_meta_objset,
6326                             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
6327                             sizeof (uint64_t), 1, &spa->spa_deflate, tx));
6328                 }
6329         }
6330 
6331         /*
6332          * Iterate to convergence.
6333          */
6334         do {
6335                 int pass = ++spa->spa_sync_pass;
6336 
6337                 spa_sync_config_object(spa, tx);
6338                 spa_sync_aux_dev(spa, &spa->spa_spares, tx,
6339                     ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
6340                 spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
6341                     ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
6342                 spa_errlog_sync(spa, txg);
6343                 dsl_pool_sync(dp, txg);
6344 
6345                 if (pass < zfs_sync_pass_deferred_free) {
6346                         spa_sync_frees(spa, free_bpl, tx);
6347                 } else {
6348                         /*
6349                          * We can not defer frees in pass 1, because
6350                          * we sync the deferred frees later in pass 1.
6351                          */
6352                         ASSERT3U(pass, >, 1);
6353                         bplist_iterate(free_bpl, bpobj_enqueue_cb,
6354                             &spa->spa_deferred_bpobj, tx);
6355                 }
6356 
6357                 ddt_sync(spa, txg);
6358                 dsl_scan_sync(dp, tx);
6359 
6360                 while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
6361                         vdev_sync(vd, txg);
6362 
6363                 if (pass == 1) {
6364                         spa_sync_upgrades(spa, tx);
6365                         ASSERT3U(txg, >=,
6366                             spa->spa_uberblock.ub_rootbp.blk_birth);
6367                         /*
6368                          * Note: We need to check if the MOS is dirty
6369                          * because we could have marked the MOS dirty
6370                          * without updating the uberblock (e.g. if we
6371                          * have sync tasks but no dirty user data).  We
6372                          * need to check the uberblock's rootbp because
6373                          * it is updated if we have synced out dirty
6374                          * data (though in this case the MOS will most
6375                          * likely also be dirty due to second order
6376                          * effects, we don't want to rely on that here).
6377                          */
6378                         if (spa->spa_uberblock.ub_rootbp.blk_birth < txg &&
6379                             !dmu_objset_is_dirty(mos, txg)) {
6380                                 /*
6381                                  * Nothing changed on the first pass,
6382                                  * therefore this TXG is a no-op.  Avoid
6383                                  * syncing deferred frees, so that we
6384                                  * can keep this TXG as a no-op.
6385                                  */
6386                                 ASSERT(txg_list_empty(&dp->dp_dirty_datasets,
6387                                     txg));
6388                                 ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
6389                                 ASSERT(txg_list_empty(&dp->dp_sync_tasks, txg));
6390                                 break;
6391                         }
6392                         spa_sync_deferred_frees(spa, tx);
6393                 }
6394 
6395         } while (dmu_objset_is_dirty(mos, txg));
6396 
6397         /*
6398          * Rewrite the vdev configuration (which includes the uberblock)
6399          * to commit the transaction group.
6400          *
6401          * If there are no dirty vdevs, we sync the uberblock to a few
6402          * random top-level vdevs that are known to be visible in the
6403          * config cache (see spa_vdev_add() for a complete description).
6404          * If there *are* dirty vdevs, sync the uberblock to all vdevs.
6405          */
6406         for (;;) {
6407                 /*
6408                  * We hold SCL_STATE to prevent vdev open/close/etc.
6409                  * while we're attempting to write the vdev labels.
6410                  */
6411                 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6412 
6413                 if (list_is_empty(&spa->spa_config_dirty_list)) {
6414                         vdev_t *svd[SPA_DVAS_PER_BP];
6415                         int svdcount = 0;
6416                         int children = rvd->vdev_children;
6417                         int c0 = spa_get_random(children);
6418 
6419                         for (int c = 0; c < children; c++) {
6420                                 vd = rvd->vdev_child[(c0 + c) % children];
6421                                 if (vd->vdev_ms_array == 0 || vd->vdev_islog)
6422                                         continue;
6423                                 svd[svdcount++] = vd;
6424                                 if (svdcount == SPA_DVAS_PER_BP)
6425                                         break;
6426                         }
6427                         error = vdev_config_sync(svd, svdcount, txg);
6428                 } else {
6429                         error = vdev_config_sync(rvd->vdev_child,
6430                             rvd->vdev_children, txg);
6431                 }
6432 
6433                 if (error == 0)
6434                         spa->spa_last_synced_guid = rvd->vdev_guid;
6435 
6436                 spa_config_exit(spa, SCL_STATE, FTAG);
6437 
6438                 if (error == 0)
6439                         break;
6440                 zio_suspend(spa, NULL);
6441                 zio_resume_wait(spa);
6442         }
6443         dmu_tx_commit(tx);
6444 
6445         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
6446 
6447         /*
6448          * Clear the dirty config list.
6449          */
6450         while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
6451                 vdev_config_clean(vd);
6452 
6453         /*
6454          * Now that the new config has synced transactionally,
6455          * let it become visible to the config cache.
6456          */
6457         if (spa->spa_config_syncing != NULL) {
6458                 spa_config_set(spa, spa->spa_config_syncing);
6459                 spa->spa_config_txg = txg;
6460                 spa->spa_config_syncing = NULL;
6461         }
6462 
6463         spa->spa_ubsync = spa->spa_uberblock;
6464 
6465         dsl_pool_sync_done(dp, txg);
6466 
6467         /*
6468          * Update usable space statistics.
6469          */
6470         while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
6471                 vdev_sync_done(vd, txg);
6472 
6473         spa_update_dspace(spa);
6474 
6475         /*
6476          * It had better be the case that we didn't dirty anything
6477          * since vdev_config_sync().
6478          */
6479         ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
6480         ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
6481         ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
6482 
6483         spa->spa_sync_pass = 0;
6484 
6485         spa_config_exit(spa, SCL_CONFIG, FTAG);
6486 
6487         spa_handle_ignored_writes(spa);
6488 
6489         /*
6490          * If any async tasks have been requested, kick them off.
6491          */
6492         spa_async_dispatch(spa);
6493 }
6494 
6495 /*
6496  * Sync all pools.  We don't want to hold the namespace lock across these
6497  * operations, so we take a reference on the spa_t and drop the lock during the
6498  * sync.
6499  */
6500 void
6501 spa_sync_allpools(void)
6502 {
6503         spa_t *spa = NULL;
6504         mutex_enter(&spa_namespace_lock);
6505         while ((spa = spa_next(spa)) != NULL) {
6506                 if (spa_state(spa) != POOL_STATE_ACTIVE ||
6507                     !spa_writeable(spa) || spa_suspended(spa))
6508                         continue;
6509                 spa_open_ref(spa, FTAG);
6510                 mutex_exit(&spa_namespace_lock);
6511                 txg_wait_synced(spa_get_dsl(spa), 0);
6512                 mutex_enter(&spa_namespace_lock);
6513                 spa_close(spa, FTAG);
6514         }
6515         mutex_exit(&spa_namespace_lock);
6516 }
6517 
6518 /*
6519  * ==========================================================================
6520  * Miscellaneous routines
6521  * ==========================================================================
6522  */
6523 
6524 /*
6525  * Remove all pools in the system.
6526  */
6527 void
6528 spa_evict_all(void)
6529 {
6530         spa_t *spa;
6531 
6532         /*
6533          * Remove all cached state.  All pools should be closed now,
6534          * so every spa in the AVL tree should be unreferenced.
6535          */
6536         mutex_enter(&spa_namespace_lock);
6537         while ((spa = spa_next(NULL)) != NULL) {
6538                 /*
6539                  * Stop async tasks.  The async thread may need to detach
6540                  * a device that's been replaced, which requires grabbing
6541                  * spa_namespace_lock, so we must drop it here.
6542                  */
6543                 spa_open_ref(spa, FTAG);
6544                 mutex_exit(&spa_namespace_lock);
6545                 spa_async_suspend(spa);
6546                 mutex_enter(&spa_namespace_lock);
6547                 spa_close(spa, FTAG);
6548 
6549                 if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
6550                         spa_unload(spa);
6551                         spa_deactivate(spa);
6552                 }
6553                 spa_remove(spa);
6554         }
6555         mutex_exit(&spa_namespace_lock);
6556 }
6557 
6558 vdev_t *
6559 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
6560 {
6561         vdev_t *vd;
6562         int i;
6563 
6564         if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
6565                 return (vd);
6566 
6567         if (aux) {
6568                 for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
6569                         vd = spa->spa_l2cache.sav_vdevs[i];
6570                         if (vd->vdev_guid == guid)
6571                                 return (vd);
6572                 }
6573 
6574                 for (i = 0; i < spa->spa_spares.sav_count; i++) {
6575                         vd = spa->spa_spares.sav_vdevs[i];
6576                         if (vd->vdev_guid == guid)
6577                                 return (vd);
6578                 }
6579         }
6580 
6581         return (NULL);
6582 }
6583 
6584 void
6585 spa_upgrade(spa_t *spa, uint64_t version)
6586 {
6587         ASSERT(spa_writeable(spa));
6588 
6589         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6590 
6591         /*
6592          * This should only be called for a non-faulted pool, and since a
6593          * future version would result in an unopenable pool, this shouldn't be
6594          * possible.
6595          */
6596         ASSERT(SPA_VERSION_IS_SUPPORTED(spa->spa_uberblock.ub_version));
6597         ASSERT3U(version, >=, spa->spa_uberblock.ub_version);
6598 
6599         spa->spa_uberblock.ub_version = version;
6600         vdev_config_dirty(spa->spa_root_vdev);
6601 
6602         spa_config_exit(spa, SCL_ALL, FTAG);
6603 
6604         txg_wait_synced(spa_get_dsl(spa), 0);
6605 }
6606 
6607 boolean_t
6608 spa_has_spare(spa_t *spa, uint64_t guid)
6609 {
6610         int i;
6611         uint64_t spareguid;
6612         spa_aux_vdev_t *sav = &spa->spa_spares;
6613 
6614         for (i = 0; i < sav->sav_count; i++)
6615                 if (sav->sav_vdevs[i]->vdev_guid == guid)
6616                         return (B_TRUE);
6617 
6618         for (i = 0; i < sav->sav_npending; i++) {
6619                 if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
6620                     &spareguid) == 0 && spareguid == guid)
6621                         return (B_TRUE);
6622         }
6623 
6624         return (B_FALSE);
6625 }
6626 
6627 /*
6628  * Check if a pool has an active shared spare device.
6629  * Note: reference count of an active spare is 2, as a spare and as a replace
6630  */
6631 static boolean_t
6632 spa_has_active_shared_spare(spa_t *spa)
6633 {
6634         int i, refcnt;
6635         uint64_t pool;
6636         spa_aux_vdev_t *sav = &spa->spa_spares;
6637 
6638         for (i = 0; i < sav->sav_count; i++) {
6639                 if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
6640                     &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
6641                     refcnt > 2)
6642                         return (B_TRUE);
6643         }
6644 
6645         return (B_FALSE);
6646 }
6647 
6648 /*
6649  * Post a sysevent corresponding to the given event.  The 'name' must be one of
6650  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
6651  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
6652  * in the userland libzpool, as we don't want consumers to misinterpret ztest
6653  * or zdb as real changes.
6654  */
6655 void
6656 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
6657 {
6658 #ifdef _KERNEL
6659         sysevent_t              *ev;
6660         sysevent_attr_list_t    *attr = NULL;
6661         sysevent_value_t        value;
6662         sysevent_id_t           eid;
6663 
6664         ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
6665             SE_SLEEP);
6666 
6667         value.value_type = SE_DATA_TYPE_STRING;
6668         value.value.sv_string = spa_name(spa);
6669         if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
6670                 goto done;
6671 
6672         value.value_type = SE_DATA_TYPE_UINT64;
6673         value.value.sv_uint64 = spa_guid(spa);
6674         if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
6675                 goto done;
6676 
6677         if (vd) {
6678                 value.value_type = SE_DATA_TYPE_UINT64;
6679                 value.value.sv_uint64 = vd->vdev_guid;
6680                 if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
6681                     SE_SLEEP) != 0)
6682                         goto done;
6683 
6684                 if (vd->vdev_path) {
6685                         value.value_type = SE_DATA_TYPE_STRING;
6686                         value.value.sv_string = vd->vdev_path;
6687                         if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
6688                             &value, SE_SLEEP) != 0)
6689                                 goto done;
6690                 }
6691         }
6692 
6693         if (sysevent_attach_attributes(ev, attr) != 0)
6694                 goto done;
6695         attr = NULL;
6696 
6697         (void) log_sysevent(ev, SE_SLEEP, &eid);
6698 
6699 done:
6700         if (attr)
6701                 sysevent_free_attr(attr);
6702         sysevent_free(ev);
6703 #endif
6704 }