1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  25  * Copyright (c) 2012 by Delphix. All rights reserved.
  26  */
  27 
  28 /*
  29  * This file contains all the routines used when modifying on-disk SPA state.
  30  * This includes opening, importing, destroying, exporting a pool, and syncing a
  31  * pool.
  32  */
  33 
  34 #include <sys/zfs_context.h>
  35 #include <sys/fm/fs/zfs.h>
  36 #include <sys/spa_impl.h>
  37 #include <sys/zio.h>
  38 #include <sys/zio_checksum.h>
  39 #include <sys/dmu.h>
  40 #include <sys/dmu_tx.h>
  41 #include <sys/zap.h>
  42 #include <sys/zil.h>
  43 #include <sys/ddt.h>
  44 #include <sys/vdev_impl.h>
  45 #include <sys/metaslab.h>
  46 #include <sys/metaslab_impl.h>
  47 #include <sys/uberblock_impl.h>
  48 #include <sys/txg.h>
  49 #include <sys/avl.h>
  50 #include <sys/dmu_traverse.h>
  51 #include <sys/dmu_objset.h>
  52 #include <sys/unique.h>
  53 #include <sys/dsl_pool.h>
  54 #include <sys/dsl_dataset.h>
  55 #include <sys/dsl_dir.h>
  56 #include <sys/dsl_prop.h>
  57 #include <sys/dsl_synctask.h>
  58 #include <sys/fs/zfs.h>
  59 #include <sys/arc.h>
  60 #include <sys/callb.h>
  61 #include <sys/systeminfo.h>
  62 #include <sys/spa_boot.h>
  63 #include <sys/zfs_ioctl.h>
  64 #include <sys/dsl_scan.h>
  65 #include <sys/zfeature.h>
  66 
  67 #ifdef  _KERNEL
  68 #include <sys/bootprops.h>
  69 #include <sys/callb.h>
  70 #include <sys/cpupart.h>
  71 #include <sys/pool.h>
  72 #include <sys/sysdc.h>
  73 #include <sys/zone.h>
  74 #endif  /* _KERNEL */
  75 
  76 #include "zfs_prop.h"
  77 #include "zfs_comutil.h"
  78 
  79 typedef enum zti_modes {
  80         zti_mode_fixed,                 /* value is # of threads (min 1) */
  81         zti_mode_online_percent,        /* value is % of online CPUs */
  82         zti_mode_batch,                 /* cpu-intensive; value is ignored */
  83         zti_mode_null,                  /* don't create a taskq */
  84         zti_nmodes
  85 } zti_modes_t;
  86 
  87 #define ZTI_FIX(n)      { zti_mode_fixed, (n) }
  88 #define ZTI_PCT(n)      { zti_mode_online_percent, (n) }
  89 #define ZTI_BATCH       { zti_mode_batch, 0 }
  90 #define ZTI_NULL        { zti_mode_null, 0 }
  91 
  92 #define ZTI_ONE         ZTI_FIX(1)
  93 
  94 typedef struct zio_taskq_info {
  95         enum zti_modes zti_mode;
  96         uint_t zti_value;
  97 } zio_taskq_info_t;
  98 
  99 static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
 100         "issue", "issue_high", "intr", "intr_high"
 101 };
 102 
 103 /*
 104  * Define the taskq threads for the following I/O types:
 105  *      NULL, READ, WRITE, FREE, CLAIM, and IOCTL
 106  */
 107 const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
 108         /* ISSUE        ISSUE_HIGH      INTR            INTR_HIGH */
 109         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL },
 110         { ZTI_FIX(8),   ZTI_NULL,       ZTI_BATCH,      ZTI_NULL },
 111         { ZTI_BATCH,    ZTI_FIX(5),     ZTI_FIX(8),     ZTI_FIX(5) },
 112         { ZTI_FIX(100), ZTI_NULL,       ZTI_ONE,        ZTI_NULL },
 113         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL },
 114         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL },
 115 };
 116 
 117 static dsl_syncfunc_t spa_sync_version;
 118 static dsl_syncfunc_t spa_sync_props;
 119 static boolean_t spa_has_active_shared_spare(spa_t *spa);
 120 static int spa_load_impl(spa_t *spa, uint64_t, nvlist_t *config,
 121     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
 122     char **ereport);
 123 static void spa_vdev_resilver_done(spa_t *spa);
 124 
 125 uint_t          zio_taskq_batch_pct = 100;      /* 1 thread per cpu in pset */
 126 id_t            zio_taskq_psrset_bind = PS_NONE;
 127 boolean_t       zio_taskq_sysdc = B_TRUE;       /* use SDC scheduling class */
 128 uint_t          zio_taskq_basedc = 80;          /* base duty cycle */
 129 
 130 boolean_t       spa_create_process = B_TRUE;    /* no process ==> no sysdc */
 131 
 132 /*
 133  * This (illegal) pool name is used when temporarily importing a spa_t in order
 134  * to get the vdev stats associated with the imported devices.
 135  */
 136 #define TRYIMPORT_NAME  "$import"
 137 
 138 /*
 139  * ==========================================================================
 140  * SPA properties routines
 141  * ==========================================================================
 142  */
 143 
 144 /*
 145  * Add a (source=src, propname=propval) list to an nvlist.
 146  */
 147 static void
 148 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, char *strval,
 149     uint64_t intval, zprop_source_t src)
 150 {
 151         const char *propname = zpool_prop_to_name(prop);
 152         nvlist_t *propval;
 153 
 154         VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 155         VERIFY(nvlist_add_uint64(propval, ZPROP_SOURCE, src) == 0);
 156 
 157         if (strval != NULL)
 158                 VERIFY(nvlist_add_string(propval, ZPROP_VALUE, strval) == 0);
 159         else
 160                 VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, intval) == 0);
 161 
 162         VERIFY(nvlist_add_nvlist(nvl, propname, propval) == 0);
 163         nvlist_free(propval);
 164 }
 165 
 166 /*
 167  * Get property values from the spa configuration.
 168  */
 169 static void
 170 spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
 171 {
 172         vdev_t *rvd = spa->spa_root_vdev;
 173         dsl_pool_t *pool = spa->spa_dsl_pool;
 174         uint64_t size;
 175         uint64_t alloc;
 176         uint64_t space;
 177         uint64_t cap, version;
 178         zprop_source_t src = ZPROP_SRC_NONE;
 179         spa_config_dirent_t *dp;
 180 
 181         ASSERT(MUTEX_HELD(&spa->spa_props_lock));
 182 
 183         if (rvd != NULL) {
 184                 alloc = metaslab_class_get_alloc(spa_normal_class(spa));
 185                 size = metaslab_class_get_space(spa_normal_class(spa));
 186                 spa_prop_add_list(*nvp, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
 187                 spa_prop_add_list(*nvp, ZPOOL_PROP_SIZE, NULL, size, src);
 188                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALLOCATED, NULL, alloc, src);
 189                 spa_prop_add_list(*nvp, ZPOOL_PROP_FREE, NULL,
 190                     size - alloc, src);
 191 
 192                 space = 0;
 193                 for (int c = 0; c < rvd->vdev_children; c++) {
 194                         vdev_t *tvd = rvd->vdev_child[c];
 195                         space += tvd->vdev_max_asize - tvd->vdev_asize;
 196                 }
 197                 spa_prop_add_list(*nvp, ZPOOL_PROP_EXPANDSZ, NULL, space,
 198                     src);
 199 
 200                 spa_prop_add_list(*nvp, ZPOOL_PROP_READONLY, NULL,
 201                     (spa_mode(spa) == FREAD), src);
 202 
 203                 cap = (size == 0) ? 0 : (alloc * 100 / size);
 204                 spa_prop_add_list(*nvp, ZPOOL_PROP_CAPACITY, NULL, cap, src);
 205 
 206                 spa_prop_add_list(*nvp, ZPOOL_PROP_DEDUPRATIO, NULL,
 207                     ddt_get_pool_dedup_ratio(spa), src);
 208 
 209                 spa_prop_add_list(*nvp, ZPOOL_PROP_HEALTH, NULL,
 210                     rvd->vdev_state, src);
 211 
 212                 version = spa_version(spa);
 213                 if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION))
 214                         src = ZPROP_SRC_DEFAULT;
 215                 else
 216                         src = ZPROP_SRC_LOCAL;
 217                 spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL, version, src);
 218         }
 219 
 220         if (pool != NULL) {
 221                 dsl_dir_t *freedir = pool->dp_free_dir;
 222 
 223                 /*
 224                  * The $FREE directory was introduced in SPA_VERSION_DEADLISTS,
 225                  * when opening pools before this version freedir will be NULL.
 226                  */
 227                 if (freedir != NULL) {
 228                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING, NULL,
 229                             freedir->dd_phys->dd_used_bytes, src);
 230                 } else {
 231                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING,
 232                             NULL, 0, src);
 233                 }
 234         }
 235 
 236         spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
 237 
 238         if (spa->spa_comment != NULL) {
 239                 spa_prop_add_list(*nvp, ZPOOL_PROP_COMMENT, spa->spa_comment,
 240                     0, ZPROP_SRC_LOCAL);
 241         }
 242 
 243         if (spa->spa_root != NULL)
 244                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
 245                     0, ZPROP_SRC_LOCAL);
 246 
 247         if ((dp = list_head(&spa->spa_config_list)) != NULL) {
 248                 if (dp->scd_path == NULL) {
 249                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 250                             "none", 0, ZPROP_SRC_LOCAL);
 251                 } else if (strcmp(dp->scd_path, spa_config_path) != 0) {
 252                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 253                             dp->scd_path, 0, ZPROP_SRC_LOCAL);
 254                 }
 255         }
 256 }
 257 
 258 /*
 259  * Get zpool property values.
 260  */
 261 int
 262 spa_prop_get(spa_t *spa, nvlist_t **nvp)
 263 {
 264         objset_t *mos = spa->spa_meta_objset;
 265         zap_cursor_t zc;
 266         zap_attribute_t za;
 267         int err;
 268 
 269         VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 270 
 271         mutex_enter(&spa->spa_props_lock);
 272 
 273         /*
 274          * Get properties from the spa config.
 275          */
 276         spa_prop_get_config(spa, nvp);
 277 
 278         /* If no pool property object, no more prop to get. */
 279         if (mos == NULL || spa->spa_pool_props_object == 0) {
 280                 mutex_exit(&spa->spa_props_lock);
 281                 return (0);
 282         }
 283 
 284         /*
 285          * Get properties from the MOS pool property object.
 286          */
 287         for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
 288             (err = zap_cursor_retrieve(&zc, &za)) == 0;
 289             zap_cursor_advance(&zc)) {
 290                 uint64_t intval = 0;
 291                 char *strval = NULL;
 292                 zprop_source_t src = ZPROP_SRC_DEFAULT;
 293                 zpool_prop_t prop;
 294 
 295                 if ((prop = zpool_name_to_prop(za.za_name)) == ZPROP_INVAL)
 296                         continue;
 297 
 298                 switch (za.za_integer_length) {
 299                 case 8:
 300                         /* integer property */
 301                         if (za.za_first_integer !=
 302                             zpool_prop_default_numeric(prop))
 303                                 src = ZPROP_SRC_LOCAL;
 304 
 305                         if (prop == ZPOOL_PROP_BOOTFS) {
 306                                 dsl_pool_t *dp;
 307                                 dsl_dataset_t *ds = NULL;
 308 
 309                                 dp = spa_get_dsl(spa);
 310                                 rw_enter(&dp->dp_config_rwlock, RW_READER);
 311                                 if (err = dsl_dataset_hold_obj(dp,
 312                                     za.za_first_integer, FTAG, &ds)) {
 313                                         rw_exit(&dp->dp_config_rwlock);
 314                                         break;
 315                                 }
 316 
 317                                 strval = kmem_alloc(
 318                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1,
 319                                     KM_SLEEP);
 320                                 dsl_dataset_name(ds, strval);
 321                                 dsl_dataset_rele(ds, FTAG);
 322                                 rw_exit(&dp->dp_config_rwlock);
 323                         } else {
 324                                 strval = NULL;
 325                                 intval = za.za_first_integer;
 326                         }
 327 
 328                         spa_prop_add_list(*nvp, prop, strval, intval, src);
 329 
 330                         if (strval != NULL)
 331                                 kmem_free(strval,
 332                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1);
 333 
 334                         break;
 335 
 336                 case 1:
 337                         /* string property */
 338                         strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
 339                         err = zap_lookup(mos, spa->spa_pool_props_object,
 340                             za.za_name, 1, za.za_num_integers, strval);
 341                         if (err) {
 342                                 kmem_free(strval, za.za_num_integers);
 343                                 break;
 344                         }
 345                         spa_prop_add_list(*nvp, prop, strval, 0, src);
 346                         kmem_free(strval, za.za_num_integers);
 347                         break;
 348 
 349                 default:
 350                         break;
 351                 }
 352         }
 353         zap_cursor_fini(&zc);
 354         mutex_exit(&spa->spa_props_lock);
 355 out:
 356         if (err && err != ENOENT) {
 357                 nvlist_free(*nvp);
 358                 *nvp = NULL;
 359                 return (err);
 360         }
 361 
 362         return (0);
 363 }
 364 
 365 /*
 366  * Validate the given pool properties nvlist and modify the list
 367  * for the property values to be set.
 368  */
 369 static int
 370 spa_prop_validate(spa_t *spa, nvlist_t *props)
 371 {
 372         nvpair_t *elem;
 373         int error = 0, reset_bootfs = 0;
 374         uint64_t objnum;
 375         boolean_t has_feature = B_FALSE;
 376 
 377         elem = NULL;
 378         while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
 379                 uint64_t intval;
 380                 char *strval, *slash, *check, *fname;
 381                 const char *propname = nvpair_name(elem);
 382                 zpool_prop_t prop = zpool_name_to_prop(propname);
 383 
 384                 switch (prop) {
 385                 case ZPROP_INVAL:
 386                         if (!zpool_prop_feature(propname)) {
 387                                 error = EINVAL;
 388                                 break;
 389                         }
 390 
 391                         /*
 392                          * Sanitize the input.
 393                          */
 394                         if (nvpair_type(elem) != DATA_TYPE_UINT64) {
 395                                 error = EINVAL;
 396                                 break;
 397                         }
 398 
 399                         if (nvpair_value_uint64(elem, &intval) != 0) {
 400                                 error = EINVAL;
 401                                 break;
 402                         }
 403 
 404                         if (intval != 0) {
 405                                 error = EINVAL;
 406                                 break;
 407                         }
 408 
 409                         fname = strchr(propname, '@') + 1;
 410                         if (zfeature_lookup_name(fname, NULL) != 0) {
 411                                 error = EINVAL;
 412                                 break;
 413                         }
 414 
 415                         has_feature = B_TRUE;
 416                         break;
 417 
 418                 case ZPOOL_PROP_VERSION:
 419                         error = nvpair_value_uint64(elem, &intval);
 420                         if (!error &&
 421                             (intval < spa_version(spa) ||
 422                             intval > SPA_VERSION_BEFORE_FEATURES ||
 423                             has_feature))
 424                                 error = EINVAL;
 425                         break;
 426 
 427                 case ZPOOL_PROP_DELEGATION:
 428                 case ZPOOL_PROP_AUTOREPLACE:
 429                 case ZPOOL_PROP_LISTSNAPS:
 430                 case ZPOOL_PROP_AUTOEXPAND:
 431                         error = nvpair_value_uint64(elem, &intval);
 432                         if (!error && intval > 1)
 433                                 error = EINVAL;
 434                         break;
 435 
 436                 case ZPOOL_PROP_BOOTFS:
 437                         /*
 438                          * If the pool version is less than SPA_VERSION_BOOTFS,
 439                          * or the pool is still being created (version == 0),
 440                          * the bootfs property cannot be set.
 441                          */
 442                         if (spa_version(spa) < SPA_VERSION_BOOTFS) {
 443                                 error = ENOTSUP;
 444                                 break;
 445                         }
 446 
 447                         /*
 448                          * Make sure the vdev config is bootable
 449                          */
 450                         if (!vdev_is_bootable(spa->spa_root_vdev)) {
 451                                 error = ENOTSUP;
 452                                 break;
 453                         }
 454 
 455                         reset_bootfs = 1;
 456 
 457                         error = nvpair_value_string(elem, &strval);
 458 
 459                         if (!error) {
 460                                 objset_t *os;
 461                                 uint64_t compress;
 462 
 463                                 if (strval == NULL || strval[0] == '\0') {
 464                                         objnum = zpool_prop_default_numeric(
 465                                             ZPOOL_PROP_BOOTFS);
 466                                         break;
 467                                 }
 468 
 469                                 if (error = dmu_objset_hold(strval, FTAG, &os))
 470                                         break;
 471 
 472                                 /* Must be ZPL and not gzip compressed. */
 473 
 474                                 if (dmu_objset_type(os) != DMU_OST_ZFS) {
 475                                         error = ENOTSUP;
 476                                 } else if ((error = dsl_prop_get_integer(strval,
 477                                     zfs_prop_to_name(ZFS_PROP_COMPRESSION),
 478                                     &compress, NULL)) == 0 &&
 479                                     !BOOTFS_COMPRESS_VALID(compress)) {
 480                                         error = ENOTSUP;
 481                                 } else {
 482                                         objnum = dmu_objset_id(os);
 483                                 }
 484                                 dmu_objset_rele(os, FTAG);
 485                         }
 486                         break;
 487 
 488                 case ZPOOL_PROP_FAILUREMODE:
 489                         error = nvpair_value_uint64(elem, &intval);
 490                         if (!error && (intval < ZIO_FAILURE_MODE_WAIT ||
 491                             intval > ZIO_FAILURE_MODE_PANIC))
 492                                 error = EINVAL;
 493 
 494                         /*
 495                          * This is a special case which only occurs when
 496                          * the pool has completely failed. This allows
 497                          * the user to change the in-core failmode property
 498                          * without syncing it out to disk (I/Os might
 499                          * currently be blocked). We do this by returning
 500                          * EIO to the caller (spa_prop_set) to trick it
 501                          * into thinking we encountered a property validation
 502                          * error.
 503                          */
 504                         if (!error && spa_suspended(spa)) {
 505                                 spa->spa_failmode = intval;
 506                                 error = EIO;
 507                         }
 508                         break;
 509 
 510                 case ZPOOL_PROP_CACHEFILE:
 511                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 512                                 break;
 513 
 514                         if (strval[0] == '\0')
 515                                 break;
 516 
 517                         if (strcmp(strval, "none") == 0)
 518                                 break;
 519 
 520                         if (strval[0] != '/') {
 521                                 error = EINVAL;
 522                                 break;
 523                         }
 524 
 525                         slash = strrchr(strval, '/');
 526                         ASSERT(slash != NULL);
 527 
 528                         if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
 529                             strcmp(slash, "/..") == 0)
 530                                 error = EINVAL;
 531                         break;
 532 
 533                 case ZPOOL_PROP_COMMENT:
 534                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 535                                 break;
 536                         for (check = strval; *check != '\0'; check++) {
 537                                 /*
 538                                  * The kernel doesn't have an easy isprint()
 539                                  * check.  For this kernel check, we merely
 540                                  * check ASCII apart from DEL.  Fix this if
 541                                  * there is an easy-to-use kernel isprint().
 542                                  */
 543                                 if (*check >= 0x7f) {
 544                                         error = EINVAL;
 545                                         break;
 546                                 }
 547                                 check++;
 548                         }
 549                         if (strlen(strval) > ZPROP_MAX_COMMENT)
 550                                 error = E2BIG;
 551                         break;
 552 
 553                 case ZPOOL_PROP_DEDUPDITTO:
 554                         if (spa_version(spa) < SPA_VERSION_DEDUP)
 555                                 error = ENOTSUP;
 556                         else
 557                                 error = nvpair_value_uint64(elem, &intval);
 558                         if (error == 0 &&
 559                             intval != 0 && intval < ZIO_DEDUPDITTO_MIN)
 560                                 error = EINVAL;
 561                         break;
 562                 }
 563 
 564                 if (error)
 565                         break;
 566         }
 567 
 568         if (!error && reset_bootfs) {
 569                 error = nvlist_remove(props,
 570                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
 571 
 572                 if (!error) {
 573                         error = nvlist_add_uint64(props,
 574                             zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
 575                 }
 576         }
 577 
 578         return (error);
 579 }
 580 
 581 void
 582 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
 583 {
 584         char *cachefile;
 585         spa_config_dirent_t *dp;
 586 
 587         if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
 588             &cachefile) != 0)
 589                 return;
 590 
 591         dp = kmem_alloc(sizeof (spa_config_dirent_t),
 592             KM_SLEEP);
 593 
 594         if (cachefile[0] == '\0')
 595                 dp->scd_path = spa_strdup(spa_config_path);
 596         else if (strcmp(cachefile, "none") == 0)
 597                 dp->scd_path = NULL;
 598         else
 599                 dp->scd_path = spa_strdup(cachefile);
 600 
 601         list_insert_head(&spa->spa_config_list, dp);
 602         if (need_sync)
 603                 spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
 604 }
 605 
 606 int
 607 spa_prop_set(spa_t *spa, nvlist_t *nvp)
 608 {
 609         int error;
 610         nvpair_t *elem = NULL;
 611         boolean_t need_sync = B_FALSE;
 612 
 613         if ((error = spa_prop_validate(spa, nvp)) != 0)
 614                 return (error);
 615 
 616         while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
 617                 zpool_prop_t prop = zpool_name_to_prop(nvpair_name(elem));
 618 
 619                 if (prop == ZPOOL_PROP_CACHEFILE ||
 620                     prop == ZPOOL_PROP_ALTROOT ||
 621                     prop == ZPOOL_PROP_READONLY)
 622                         continue;
 623 
 624                 if (prop == ZPOOL_PROP_VERSION || prop == ZPROP_INVAL) {
 625                         uint64_t ver;
 626 
 627                         if (prop == ZPOOL_PROP_VERSION) {
 628                                 VERIFY(nvpair_value_uint64(elem, &ver) == 0);
 629                         } else {
 630                                 ASSERT(zpool_prop_feature(nvpair_name(elem)));
 631                                 ver = SPA_VERSION_FEATURES;
 632                                 need_sync = B_TRUE;
 633                         }
 634 
 635                         /* Save time if the version is already set. */
 636                         if (ver == spa_version(spa))
 637                                 continue;
 638 
 639                         /*
 640                          * In addition to the pool directory object, we might
 641                          * create the pool properties object, the features for
 642                          * read object, the features for write object, or the
 643                          * feature descriptions object.
 644                          */
 645                         error = dsl_sync_task_do(spa_get_dsl(spa), NULL,
 646                             spa_sync_version, spa, &ver, 6);
 647                         if (error)
 648                                 return (error);
 649                         continue;
 650                 }
 651 
 652                 need_sync = B_TRUE;
 653                 break;
 654         }
 655 
 656         if (need_sync) {
 657                 return (dsl_sync_task_do(spa_get_dsl(spa), NULL, spa_sync_props,
 658                     spa, nvp, 6));
 659         }
 660 
 661         return (0);
 662 }
 663 
 664 /*
 665  * If the bootfs property value is dsobj, clear it.
 666  */
 667 void
 668 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
 669 {
 670         if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
 671                 VERIFY(zap_remove(spa->spa_meta_objset,
 672                     spa->spa_pool_props_object,
 673                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
 674                 spa->spa_bootfs = 0;
 675         }
 676 }
 677 
 678 /*
 679  * Change the GUID for the pool.  This is done so that we can later
 680  * re-import a pool built from a clone of our own vdevs.  We will modify
 681  * the root vdev's guid, our own pool guid, and then mark all of our
 682  * vdevs dirty.  Note that we must make sure that all our vdevs are
 683  * online when we do this, or else any vdevs that weren't present
 684  * would be orphaned from our pool.  We are also going to issue a
 685  * sysevent to update any watchers.
 686  */
 687 int
 688 spa_change_guid(spa_t *spa)
 689 {
 690         uint64_t        oldguid, newguid;
 691         uint64_t        txg;
 692 
 693         if (!(spa_mode_global & FWRITE))
 694                 return (EROFS);
 695 
 696         txg = spa_vdev_enter(spa);
 697 
 698         if (spa->spa_root_vdev->vdev_state != VDEV_STATE_HEALTHY)
 699                 return (spa_vdev_exit(spa, NULL, txg, ENXIO));
 700 
 701         oldguid = spa_guid(spa);
 702         newguid = spa_generate_guid(NULL);
 703         ASSERT3U(oldguid, !=, newguid);
 704 
 705         spa->spa_root_vdev->vdev_guid = newguid;
 706         spa->spa_root_vdev->vdev_guid_sum += (newguid - oldguid);
 707 
 708         vdev_config_dirty(spa->spa_root_vdev);
 709 
 710         spa_event_notify(spa, NULL, ESC_ZFS_POOL_REGUID);
 711 
 712         return (spa_vdev_exit(spa, NULL, txg, 0));
 713 }
 714 
 715 /*
 716  * ==========================================================================
 717  * SPA state manipulation (open/create/destroy/import/export)
 718  * ==========================================================================
 719  */
 720 
 721 static int
 722 spa_error_entry_compare(const void *a, const void *b)
 723 {
 724         spa_error_entry_t *sa = (spa_error_entry_t *)a;
 725         spa_error_entry_t *sb = (spa_error_entry_t *)b;
 726         int ret;
 727 
 728         ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
 729             sizeof (zbookmark_t));
 730 
 731         if (ret < 0)
 732                 return (-1);
 733         else if (ret > 0)
 734                 return (1);
 735         else
 736                 return (0);
 737 }
 738 
 739 /*
 740  * Utility function which retrieves copies of the current logs and
 741  * re-initializes them in the process.
 742  */
 743 void
 744 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
 745 {
 746         ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
 747 
 748         bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
 749         bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));
 750 
 751         avl_create(&spa->spa_errlist_scrub,
 752             spa_error_entry_compare, sizeof (spa_error_entry_t),
 753             offsetof(spa_error_entry_t, se_avl));
 754         avl_create(&spa->spa_errlist_last,
 755             spa_error_entry_compare, sizeof (spa_error_entry_t),
 756             offsetof(spa_error_entry_t, se_avl));
 757 }
 758 
 759 static taskq_t *
 760 spa_taskq_create(spa_t *spa, const char *name, enum zti_modes mode,
 761     uint_t value)
 762 {
 763         uint_t flags = 0;
 764         boolean_t batch = B_FALSE;
 765 
 766         switch (mode) {
 767         case zti_mode_null:
 768                 return (NULL);          /* no taskq needed */
 769 
 770         case zti_mode_fixed:
 771                 ASSERT3U(value, >=, 1);
 772                 value = MAX(value, 1);
 773                 break;
 774 
 775         case zti_mode_batch:
 776                 batch = B_TRUE;
 777                 flags |= TASKQ_THREADS_CPU_PCT;
 778                 value = zio_taskq_batch_pct;
 779                 break;
 780 
 781         case zti_mode_online_percent:
 782                 flags |= TASKQ_THREADS_CPU_PCT;
 783                 break;
 784 
 785         default:
 786                 panic("unrecognized mode for %s taskq (%u:%u) in "
 787                     "spa_activate()",
 788                     name, mode, value);
 789                 break;
 790         }
 791 
 792         if (zio_taskq_sysdc && spa->spa_proc != &p0) {
 793                 if (batch)
 794                         flags |= TASKQ_DC_BATCH;
 795 
 796                 return (taskq_create_sysdc(name, value, 50, INT_MAX,
 797                     spa->spa_proc, zio_taskq_basedc, flags));
 798         }
 799         return (taskq_create_proc(name, value, maxclsyspri, 50, INT_MAX,
 800             spa->spa_proc, flags));
 801 }
 802 
 803 static void
 804 spa_create_zio_taskqs(spa_t *spa)
 805 {
 806         for (int t = 0; t < ZIO_TYPES; t++) {
 807                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
 808                         const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
 809                         enum zti_modes mode = ztip->zti_mode;
 810                         uint_t value = ztip->zti_value;
 811                         char name[32];
 812 
 813                         (void) snprintf(name, sizeof (name),
 814                             "%s_%s", zio_type_name[t], zio_taskq_types[q]);
 815 
 816                         spa->spa_zio_taskq[t][q] =
 817                             spa_taskq_create(spa, name, mode, value);
 818                 }
 819         }
 820 }
 821 
 822 #ifdef _KERNEL
 823 static void
 824 spa_thread(void *arg)
 825 {
 826         callb_cpr_t cprinfo;
 827 
 828         spa_t *spa = arg;
 829         user_t *pu = PTOU(curproc);
 830 
 831         CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
 832             spa->spa_name);
 833 
 834         ASSERT(curproc != &p0);
 835         (void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
 836             "zpool-%s", spa->spa_name);
 837         (void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
 838 
 839         /* bind this thread to the requested psrset */
 840         if (zio_taskq_psrset_bind != PS_NONE) {
 841                 pool_lock();
 842                 mutex_enter(&cpu_lock);
 843                 mutex_enter(&pidlock);
 844                 mutex_enter(&curproc->p_lock);
 845 
 846                 if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
 847                     0, NULL, NULL) == 0)  {
 848                         curthread->t_bind_pset = zio_taskq_psrset_bind;
 849                 } else {
 850                         cmn_err(CE_WARN,
 851                             "Couldn't bind process for zfs pool \"%s\" to "
 852                             "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
 853                 }
 854 
 855                 mutex_exit(&curproc->p_lock);
 856                 mutex_exit(&pidlock);
 857                 mutex_exit(&cpu_lock);
 858                 pool_unlock();
 859         }
 860 
 861         if (zio_taskq_sysdc) {
 862                 sysdc_thread_enter(curthread, 100, 0);
 863         }
 864 
 865         spa->spa_proc = curproc;
 866         spa->spa_did = curthread->t_did;
 867 
 868         spa_create_zio_taskqs(spa);
 869 
 870         mutex_enter(&spa->spa_proc_lock);
 871         ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
 872 
 873         spa->spa_proc_state = SPA_PROC_ACTIVE;
 874         cv_broadcast(&spa->spa_proc_cv);
 875 
 876         CALLB_CPR_SAFE_BEGIN(&cprinfo);
 877         while (spa->spa_proc_state == SPA_PROC_ACTIVE)
 878                 cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
 879         CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
 880 
 881         ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
 882         spa->spa_proc_state = SPA_PROC_GONE;
 883         spa->spa_proc = &p0;
 884         cv_broadcast(&spa->spa_proc_cv);
 885         CALLB_CPR_EXIT(&cprinfo);   /* drops spa_proc_lock */
 886 
 887         mutex_enter(&curproc->p_lock);
 888         lwp_exit();
 889 }
 890 #endif
 891 
 892 /*
 893  * Activate an uninitialized pool.
 894  */
 895 static void
 896 spa_activate(spa_t *spa, int mode)
 897 {
 898         ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
 899 
 900         spa->spa_state = POOL_STATE_ACTIVE;
 901         spa->spa_mode = mode;
 902 
 903         spa->spa_normal_class = metaslab_class_create(spa, zfs_metaslab_ops);
 904         spa->spa_log_class = metaslab_class_create(spa, zfs_metaslab_ops);
 905 
 906         /* Try to create a covering process */
 907         mutex_enter(&spa->spa_proc_lock);
 908         ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
 909         ASSERT(spa->spa_proc == &p0);
 910         spa->spa_did = 0;
 911 
 912         /* Only create a process if we're going to be around a while. */
 913         if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
 914                 if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
 915                     NULL, 0) == 0) {
 916                         spa->spa_proc_state = SPA_PROC_CREATED;
 917                         while (spa->spa_proc_state == SPA_PROC_CREATED) {
 918                                 cv_wait(&spa->spa_proc_cv,
 919                                     &spa->spa_proc_lock);
 920                         }
 921                         ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
 922                         ASSERT(spa->spa_proc != &p0);
 923                         ASSERT(spa->spa_did != 0);
 924                 } else {
 925 #ifdef _KERNEL
 926                         cmn_err(CE_WARN,
 927                             "Couldn't create process for zfs pool \"%s\"\n",
 928                             spa->spa_name);
 929 #endif
 930                 }
 931         }
 932         mutex_exit(&spa->spa_proc_lock);
 933 
 934         /* If we didn't create a process, we need to create our taskqs. */
 935         if (spa->spa_proc == &p0) {
 936                 spa_create_zio_taskqs(spa);
 937         }
 938 
 939         list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
 940             offsetof(vdev_t, vdev_config_dirty_node));
 941         list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
 942             offsetof(vdev_t, vdev_state_dirty_node));
 943 
 944         txg_list_create(&spa->spa_vdev_txg_list,
 945             offsetof(struct vdev, vdev_txg_node));
 946 
 947         avl_create(&spa->spa_errlist_scrub,
 948             spa_error_entry_compare, sizeof (spa_error_entry_t),
 949             offsetof(spa_error_entry_t, se_avl));
 950         avl_create(&spa->spa_errlist_last,
 951             spa_error_entry_compare, sizeof (spa_error_entry_t),
 952             offsetof(spa_error_entry_t, se_avl));
 953 }
 954 
 955 /*
 956  * Opposite of spa_activate().
 957  */
 958 static void
 959 spa_deactivate(spa_t *spa)
 960 {
 961         ASSERT(spa->spa_sync_on == B_FALSE);
 962         ASSERT(spa->spa_dsl_pool == NULL);
 963         ASSERT(spa->spa_root_vdev == NULL);
 964         ASSERT(spa->spa_async_zio_root == NULL);
 965         ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
 966 
 967         txg_list_destroy(&spa->spa_vdev_txg_list);
 968 
 969         list_destroy(&spa->spa_config_dirty_list);
 970         list_destroy(&spa->spa_state_dirty_list);
 971 
 972         for (int t = 0; t < ZIO_TYPES; t++) {
 973                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
 974                         if (spa->spa_zio_taskq[t][q] != NULL)
 975                                 taskq_destroy(spa->spa_zio_taskq[t][q]);
 976                         spa->spa_zio_taskq[t][q] = NULL;
 977                 }
 978         }
 979 
 980         metaslab_class_destroy(spa->spa_normal_class);
 981         spa->spa_normal_class = NULL;
 982 
 983         metaslab_class_destroy(spa->spa_log_class);
 984         spa->spa_log_class = NULL;
 985 
 986         /*
 987          * If this was part of an import or the open otherwise failed, we may
 988          * still have errors left in the queues.  Empty them just in case.
 989          */
 990         spa_errlog_drain(spa);
 991 
 992         avl_destroy(&spa->spa_errlist_scrub);
 993         avl_destroy(&spa->spa_errlist_last);
 994 
 995         spa->spa_state = POOL_STATE_UNINITIALIZED;
 996 
 997         mutex_enter(&spa->spa_proc_lock);
 998         if (spa->spa_proc_state != SPA_PROC_NONE) {
 999                 ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1000                 spa->spa_proc_state = SPA_PROC_DEACTIVATE;
1001                 cv_broadcast(&spa->spa_proc_cv);
1002                 while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
1003                         ASSERT(spa->spa_proc != &p0);
1004                         cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1005                 }
1006                 ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
1007                 spa->spa_proc_state = SPA_PROC_NONE;
1008         }
1009         ASSERT(spa->spa_proc == &p0);
1010         mutex_exit(&spa->spa_proc_lock);
1011 
1012         /*
1013          * We want to make sure spa_thread() has actually exited the ZFS
1014          * module, so that the module can't be unloaded out from underneath
1015          * it.
1016          */
1017         if (spa->spa_did != 0) {
1018                 thread_join(spa->spa_did);
1019                 spa->spa_did = 0;
1020         }
1021 }
1022 
1023 /*
1024  * Verify a pool configuration, and construct the vdev tree appropriately.  This
1025  * will create all the necessary vdevs in the appropriate layout, with each vdev
1026  * in the CLOSED state.  This will prep the pool before open/creation/import.
1027  * All vdev validation is done by the vdev_alloc() routine.
1028  */
1029 static int
1030 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
1031     uint_t id, int atype)
1032 {
1033         nvlist_t **child;
1034         uint_t children;
1035         int error;
1036 
1037         if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
1038                 return (error);
1039 
1040         if ((*vdp)->vdev_ops->vdev_op_leaf)
1041                 return (0);
1042 
1043         error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
1044             &child, &children);
1045 
1046         if (error == ENOENT)
1047                 return (0);
1048 
1049         if (error) {
1050                 vdev_free(*vdp);
1051                 *vdp = NULL;
1052                 return (EINVAL);
1053         }
1054 
1055         for (int c = 0; c < children; c++) {
1056                 vdev_t *vd;
1057                 if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
1058                     atype)) != 0) {
1059                         vdev_free(*vdp);
1060                         *vdp = NULL;
1061                         return (error);
1062                 }
1063         }
1064 
1065         ASSERT(*vdp != NULL);
1066 
1067         return (0);
1068 }
1069 
1070 /*
1071  * Opposite of spa_load().
1072  */
1073 static void
1074 spa_unload(spa_t *spa)
1075 {
1076         int i;
1077 
1078         ASSERT(MUTEX_HELD(&spa_namespace_lock));
1079 
1080         /*
1081          * Stop async tasks.
1082          */
1083         spa_async_suspend(spa);
1084 
1085         /*
1086          * Stop syncing.
1087          */
1088         if (spa->spa_sync_on) {
1089                 txg_sync_stop(spa->spa_dsl_pool);
1090                 spa->spa_sync_on = B_FALSE;
1091         }
1092 
1093         /*
1094          * Wait for any outstanding async I/O to complete.
1095          */
1096         if (spa->spa_async_zio_root != NULL) {
1097                 (void) zio_wait(spa->spa_async_zio_root);
1098                 spa->spa_async_zio_root = NULL;
1099         }
1100 
1101         bpobj_close(&spa->spa_deferred_bpobj);
1102 
1103         /*
1104          * Close the dsl pool.
1105          */
1106         if (spa->spa_dsl_pool) {
1107                 dsl_pool_close(spa->spa_dsl_pool);
1108                 spa->spa_dsl_pool = NULL;
1109                 spa->spa_meta_objset = NULL;
1110         }
1111 
1112         ddt_unload(spa);
1113 
1114         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1115 
1116         /*
1117          * Drop and purge level 2 cache
1118          */
1119         spa_l2cache_drop(spa);
1120 
1121         /*
1122          * Close all vdevs.
1123          */
1124         if (spa->spa_root_vdev)
1125                 vdev_free(spa->spa_root_vdev);
1126         ASSERT(spa->spa_root_vdev == NULL);
1127 
1128         for (i = 0; i < spa->spa_spares.sav_count; i++)
1129                 vdev_free(spa->spa_spares.sav_vdevs[i]);
1130         if (spa->spa_spares.sav_vdevs) {
1131                 kmem_free(spa->spa_spares.sav_vdevs,
1132                     spa->spa_spares.sav_count * sizeof (void *));
1133                 spa->spa_spares.sav_vdevs = NULL;
1134         }
1135         if (spa->spa_spares.sav_config) {
1136                 nvlist_free(spa->spa_spares.sav_config);
1137                 spa->spa_spares.sav_config = NULL;
1138         }
1139         spa->spa_spares.sav_count = 0;
1140 
1141         for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
1142                 vdev_clear_stats(spa->spa_l2cache.sav_vdevs[i]);
1143                 vdev_free(spa->spa_l2cache.sav_vdevs[i]);
1144         }
1145         if (spa->spa_l2cache.sav_vdevs) {
1146                 kmem_free(spa->spa_l2cache.sav_vdevs,
1147                     spa->spa_l2cache.sav_count * sizeof (void *));
1148                 spa->spa_l2cache.sav_vdevs = NULL;
1149         }
1150         if (spa->spa_l2cache.sav_config) {
1151                 nvlist_free(spa->spa_l2cache.sav_config);
1152                 spa->spa_l2cache.sav_config = NULL;
1153         }
1154         spa->spa_l2cache.sav_count = 0;
1155 
1156         spa->spa_async_suspended = 0;
1157 
1158         if (spa->spa_comment != NULL) {
1159                 spa_strfree(spa->spa_comment);
1160                 spa->spa_comment = NULL;
1161         }
1162 
1163         spa_config_exit(spa, SCL_ALL, FTAG);
1164 }
1165 
1166 /*
1167  * Load (or re-load) the current list of vdevs describing the active spares for
1168  * this pool.  When this is called, we have some form of basic information in
1169  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
1170  * then re-generate a more complete list including status information.
1171  */
1172 static void
1173 spa_load_spares(spa_t *spa)
1174 {
1175         nvlist_t **spares;
1176         uint_t nspares;
1177         int i;
1178         vdev_t *vd, *tvd;
1179 
1180         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1181 
1182         /*
1183          * First, close and free any existing spare vdevs.
1184          */
1185         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1186                 vd = spa->spa_spares.sav_vdevs[i];
1187 
1188                 /* Undo the call to spa_activate() below */
1189                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1190                     B_FALSE)) != NULL && tvd->vdev_isspare)
1191                         spa_spare_remove(tvd);
1192                 vdev_close(vd);
1193                 vdev_free(vd);
1194         }
1195 
1196         if (spa->spa_spares.sav_vdevs)
1197                 kmem_free(spa->spa_spares.sav_vdevs,
1198                     spa->spa_spares.sav_count * sizeof (void *));
1199 
1200         if (spa->spa_spares.sav_config == NULL)
1201                 nspares = 0;
1202         else
1203                 VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1204                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1205 
1206         spa->spa_spares.sav_count = (int)nspares;
1207         spa->spa_spares.sav_vdevs = NULL;
1208 
1209         if (nspares == 0)
1210                 return;
1211 
1212         /*
1213          * Construct the array of vdevs, opening them to get status in the
1214          * process.   For each spare, there is potentially two different vdev_t
1215          * structures associated with it: one in the list of spares (used only
1216          * for basic validation purposes) and one in the active vdev
1217          * configuration (if it's spared in).  During this phase we open and
1218          * validate each vdev on the spare list.  If the vdev also exists in the
1219          * active configuration, then we also mark this vdev as an active spare.
1220          */
1221         spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
1222             KM_SLEEP);
1223         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1224                 VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
1225                     VDEV_ALLOC_SPARE) == 0);
1226                 ASSERT(vd != NULL);
1227 
1228                 spa->spa_spares.sav_vdevs[i] = vd;
1229 
1230                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1231                     B_FALSE)) != NULL) {
1232                         if (!tvd->vdev_isspare)
1233                                 spa_spare_add(tvd);
1234 
1235                         /*
1236                          * We only mark the spare active if we were successfully
1237                          * able to load the vdev.  Otherwise, importing a pool
1238                          * with a bad active spare would result in strange
1239                          * behavior, because multiple pool would think the spare
1240                          * is actively in use.
1241                          *
1242                          * There is a vulnerability here to an equally bizarre
1243                          * circumstance, where a dead active spare is later
1244                          * brought back to life (onlined or otherwise).  Given
1245                          * the rarity of this scenario, and the extra complexity
1246                          * it adds, we ignore the possibility.
1247                          */
1248                         if (!vdev_is_dead(tvd))
1249                                 spa_spare_activate(tvd);
1250                 }
1251 
1252                 vd->vdev_top = vd;
1253                 vd->vdev_aux = &spa->spa_spares;
1254 
1255                 if (vdev_open(vd) != 0)
1256                         continue;
1257 
1258                 if (vdev_validate_aux(vd) == 0)
1259                         spa_spare_add(vd);
1260         }
1261 
1262         /*
1263          * Recompute the stashed list of spares, with status information
1264          * this time.
1265          */
1266         VERIFY(nvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES,
1267             DATA_TYPE_NVLIST_ARRAY) == 0);
1268 
1269         spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
1270             KM_SLEEP);
1271         for (i = 0; i < spa->spa_spares.sav_count; i++)
1272                 spares[i] = vdev_config_generate(spa,
1273                     spa->spa_spares.sav_vdevs[i], B_TRUE, VDEV_CONFIG_SPARE);
1274         VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
1275             ZPOOL_CONFIG_SPARES, spares, spa->spa_spares.sav_count) == 0);
1276         for (i = 0; i < spa->spa_spares.sav_count; i++)
1277                 nvlist_free(spares[i]);
1278         kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
1279 }
1280 
1281 /*
1282  * Load (or re-load) the current list of vdevs describing the active l2cache for
1283  * this pool.  When this is called, we have some form of basic information in
1284  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
1285  * then re-generate a more complete list including status information.
1286  * Devices which are already active have their details maintained, and are
1287  * not re-opened.
1288  */
1289 static void
1290 spa_load_l2cache(spa_t *spa)
1291 {
1292         nvlist_t **l2cache;
1293         uint_t nl2cache;
1294         int i, j, oldnvdevs;
1295         uint64_t guid;
1296         vdev_t *vd, **oldvdevs, **newvdevs;
1297         spa_aux_vdev_t *sav = &spa->spa_l2cache;
1298 
1299         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1300 
1301         if (sav->sav_config != NULL) {
1302                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
1303                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1304                 newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
1305         } else {
1306                 nl2cache = 0;
1307         }
1308 
1309         oldvdevs = sav->sav_vdevs;
1310         oldnvdevs = sav->sav_count;
1311         sav->sav_vdevs = NULL;
1312         sav->sav_count = 0;
1313 
1314         /*
1315          * Process new nvlist of vdevs.
1316          */
1317         for (i = 0; i < nl2cache; i++) {
1318                 VERIFY(nvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID,
1319                     &guid) == 0);
1320 
1321                 newvdevs[i] = NULL;
1322                 for (j = 0; j < oldnvdevs; j++) {
1323                         vd = oldvdevs[j];
1324                         if (vd != NULL && guid == vd->vdev_guid) {
1325                                 /*
1326                                  * Retain previous vdev for add/remove ops.
1327                                  */
1328                                 newvdevs[i] = vd;
1329                                 oldvdevs[j] = NULL;
1330                                 break;
1331                         }
1332                 }
1333 
1334                 if (newvdevs[i] == NULL) {
1335                         /*
1336                          * Create new vdev
1337                          */
1338                         VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
1339                             VDEV_ALLOC_L2CACHE) == 0);
1340                         ASSERT(vd != NULL);
1341                         newvdevs[i] = vd;
1342 
1343                         /*
1344                          * Commit this vdev as an l2cache device,
1345                          * even if it fails to open.
1346                          */
1347                         spa_l2cache_add(vd);
1348 
1349                         vd->vdev_top = vd;
1350                         vd->vdev_aux = sav;
1351 
1352                         spa_l2cache_activate(vd);
1353 
1354                         if (vdev_open(vd) != 0)
1355                                 continue;
1356 
1357                         (void) vdev_validate_aux(vd);
1358 
1359                         if (!vdev_is_dead(vd))
1360                                 l2arc_add_vdev(spa, vd);
1361                 }
1362         }
1363 
1364         /*
1365          * Purge vdevs that were dropped
1366          */
1367         for (i = 0; i < oldnvdevs; i++) {
1368                 uint64_t pool;
1369 
1370                 vd = oldvdevs[i];
1371                 if (vd != NULL) {
1372                         ASSERT(vd->vdev_isl2cache);
1373 
1374                         if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
1375                             pool != 0ULL && l2arc_vdev_present(vd))
1376                                 l2arc_remove_vdev(vd);
1377                         vdev_clear_stats(vd);
1378                         vdev_free(vd);
1379                 }
1380         }
1381 
1382         if (oldvdevs)
1383                 kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
1384 
1385         if (sav->sav_config == NULL)
1386                 goto out;
1387 
1388         sav->sav_vdevs = newvdevs;
1389         sav->sav_count = (int)nl2cache;
1390 
1391         /*
1392          * Recompute the stashed list of l2cache devices, with status
1393          * information this time.
1394          */
1395         VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
1396             DATA_TYPE_NVLIST_ARRAY) == 0);
1397 
1398         l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
1399         for (i = 0; i < sav->sav_count; i++)
1400                 l2cache[i] = vdev_config_generate(spa,
1401                     sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);
1402         VERIFY(nvlist_add_nvlist_array(sav->sav_config,
1403             ZPOOL_CONFIG_L2CACHE, l2cache, sav->sav_count) == 0);
1404 out:
1405         for (i = 0; i < sav->sav_count; i++)
1406                 nvlist_free(l2cache[i]);
1407         if (sav->sav_count)
1408                 kmem_free(l2cache, sav->sav_count * sizeof (void *));
1409 }
1410 
1411 static int
1412 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
1413 {
1414         dmu_buf_t *db;
1415         char *packed = NULL;
1416         size_t nvsize = 0;
1417         int error;
1418         *value = NULL;
1419 
1420         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
1421         nvsize = *(uint64_t *)db->db_data;
1422         dmu_buf_rele(db, FTAG);
1423 
1424         packed = kmem_alloc(nvsize, KM_SLEEP);
1425         error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
1426             DMU_READ_PREFETCH);
1427         if (error == 0)
1428                 error = nvlist_unpack(packed, nvsize, value, 0);
1429         kmem_free(packed, nvsize);
1430 
1431         return (error);
1432 }
1433 
1434 /*
1435  * Checks to see if the given vdev could not be opened, in which case we post a
1436  * sysevent to notify the autoreplace code that the device has been removed.
1437  */
1438 static void
1439 spa_check_removed(vdev_t *vd)
1440 {
1441         for (int c = 0; c < vd->vdev_children; c++)
1442                 spa_check_removed(vd->vdev_child[c]);
1443 
1444         if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd)) {
1445                 zfs_post_autoreplace(vd->vdev_spa, vd);
1446                 spa_event_notify(vd->vdev_spa, vd, ESC_ZFS_VDEV_CHECK);
1447         }
1448 }
1449 
1450 /*
1451  * Validate the current config against the MOS config
1452  */
1453 static boolean_t
1454 spa_config_valid(spa_t *spa, nvlist_t *config)
1455 {
1456         vdev_t *mrvd, *rvd = spa->spa_root_vdev;
1457         nvlist_t *nv;
1458 
1459         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nv) == 0);
1460 
1461         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1462         VERIFY(spa_config_parse(spa, &mrvd, nv, NULL, 0, VDEV_ALLOC_LOAD) == 0);
1463 
1464         ASSERT3U(rvd->vdev_children, ==, mrvd->vdev_children);
1465 
1466         /*
1467          * If we're doing a normal import, then build up any additional
1468          * diagnostic information about missing devices in this config.
1469          * We'll pass this up to the user for further processing.
1470          */
1471         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG)) {
1472                 nvlist_t **child, *nv;
1473                 uint64_t idx = 0;
1474 
1475                 child = kmem_alloc(rvd->vdev_children * sizeof (nvlist_t **),
1476                     KM_SLEEP);
1477                 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1478 
1479                 for (int c = 0; c < rvd->vdev_children; c++) {
1480                         vdev_t *tvd = rvd->vdev_child[c];
1481                         vdev_t *mtvd  = mrvd->vdev_child[c];
1482 
1483                         if (tvd->vdev_ops == &vdev_missing_ops &&
1484                             mtvd->vdev_ops != &vdev_missing_ops &&
1485                             mtvd->vdev_islog)
1486                                 child[idx++] = vdev_config_generate(spa, mtvd,
1487                                     B_FALSE, 0);
1488                 }
1489 
1490                 if (idx) {
1491                         VERIFY(nvlist_add_nvlist_array(nv,
1492                             ZPOOL_CONFIG_CHILDREN, child, idx) == 0);
1493                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
1494                             ZPOOL_CONFIG_MISSING_DEVICES, nv) == 0);
1495 
1496                         for (int i = 0; i < idx; i++)
1497                                 nvlist_free(child[i]);
1498                 }
1499                 nvlist_free(nv);
1500                 kmem_free(child, rvd->vdev_children * sizeof (char **));
1501         }
1502 
1503         /*
1504          * Compare the root vdev tree with the information we have
1505          * from the MOS config (mrvd). Check each top-level vdev
1506          * with the corresponding MOS config top-level (mtvd).
1507          */
1508         for (int c = 0; c < rvd->vdev_children; c++) {
1509                 vdev_t *tvd = rvd->vdev_child[c];
1510                 vdev_t *mtvd  = mrvd->vdev_child[c];
1511 
1512                 /*
1513                  * Resolve any "missing" vdevs in the current configuration.
1514                  * If we find that the MOS config has more accurate information
1515                  * about the top-level vdev then use that vdev instead.
1516                  */
1517                 if (tvd->vdev_ops == &vdev_missing_ops &&
1518                     mtvd->vdev_ops != &vdev_missing_ops) {
1519 
1520                         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG))
1521                                 continue;
1522 
1523                         /*
1524                          * Device specific actions.
1525                          */
1526                         if (mtvd->vdev_islog) {
1527                                 spa_set_log_state(spa, SPA_LOG_CLEAR);
1528                         } else {
1529                                 /*
1530                                  * XXX - once we have 'readonly' pool
1531                                  * support we should be able to handle
1532                                  * missing data devices by transitioning
1533                                  * the pool to readonly.
1534                                  */
1535                                 continue;
1536                         }
1537 
1538                         /*
1539                          * Swap the missing vdev with the data we were
1540                          * able to obtain from the MOS config.
1541                          */
1542                         vdev_remove_child(rvd, tvd);
1543                         vdev_remove_child(mrvd, mtvd);
1544 
1545                         vdev_add_child(rvd, mtvd);
1546                         vdev_add_child(mrvd, tvd);
1547 
1548                         spa_config_exit(spa, SCL_ALL, FTAG);
1549                         vdev_load(mtvd);
1550                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1551 
1552                         vdev_reopen(rvd);
1553                 } else if (mtvd->vdev_islog) {
1554                         /*
1555                          * Load the slog device's state from the MOS config
1556                          * since it's possible that the label does not
1557                          * contain the most up-to-date information.
1558                          */
1559                         vdev_load_log_state(tvd, mtvd);
1560                         vdev_reopen(tvd);
1561                 }
1562         }
1563         vdev_free(mrvd);
1564         spa_config_exit(spa, SCL_ALL, FTAG);
1565 
1566         /*
1567          * Ensure we were able to validate the config.
1568          */
1569         return (rvd->vdev_guid_sum == spa->spa_uberblock.ub_guid_sum);
1570 }
1571 
1572 /*
1573  * Check for missing log devices
1574  */
1575 static int
1576 spa_check_logs(spa_t *spa)
1577 {
1578         switch (spa->spa_log_state) {
1579         case SPA_LOG_MISSING:
1580                 /* need to recheck in case slog has been restored */
1581         case SPA_LOG_UNKNOWN:
1582                 if (dmu_objset_find(spa->spa_name, zil_check_log_chain, NULL,
1583                     DS_FIND_CHILDREN)) {
1584                         spa_set_log_state(spa, SPA_LOG_MISSING);
1585                         return (1);
1586                 }
1587                 break;
1588         }
1589         return (0);
1590 }
1591 
1592 static boolean_t
1593 spa_passivate_log(spa_t *spa)
1594 {
1595         vdev_t *rvd = spa->spa_root_vdev;
1596         boolean_t slog_found = B_FALSE;
1597 
1598         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1599 
1600         if (!spa_has_slogs(spa))
1601                 return (B_FALSE);
1602 
1603         for (int c = 0; c < rvd->vdev_children; c++) {
1604                 vdev_t *tvd = rvd->vdev_child[c];
1605                 metaslab_group_t *mg = tvd->vdev_mg;
1606 
1607                 if (tvd->vdev_islog) {
1608                         metaslab_group_passivate(mg);
1609                         slog_found = B_TRUE;
1610                 }
1611         }
1612 
1613         return (slog_found);
1614 }
1615 
1616 static void
1617 spa_activate_log(spa_t *spa)
1618 {
1619         vdev_t *rvd = spa->spa_root_vdev;
1620 
1621         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1622 
1623         for (int c = 0; c < rvd->vdev_children; c++) {
1624                 vdev_t *tvd = rvd->vdev_child[c];
1625                 metaslab_group_t *mg = tvd->vdev_mg;
1626 
1627                 if (tvd->vdev_islog)
1628                         metaslab_group_activate(mg);
1629         }
1630 }
1631 
1632 int
1633 spa_offline_log(spa_t *spa)
1634 {
1635         int error = 0;
1636 
1637         if ((error = dmu_objset_find(spa_name(spa), zil_vdev_offline,
1638             NULL, DS_FIND_CHILDREN)) == 0) {
1639 
1640                 /*
1641                  * We successfully offlined the log device, sync out the
1642                  * current txg so that the "stubby" block can be removed
1643                  * by zil_sync().
1644                  */
1645                 txg_wait_synced(spa->spa_dsl_pool, 0);
1646         }
1647         return (error);
1648 }
1649 
1650 static void
1651 spa_aux_check_removed(spa_aux_vdev_t *sav)
1652 {
1653         for (int i = 0; i < sav->sav_count; i++)
1654                 spa_check_removed(sav->sav_vdevs[i]);
1655 }
1656 
1657 void
1658 spa_claim_notify(zio_t *zio)
1659 {
1660         spa_t *spa = zio->io_spa;
1661 
1662         if (zio->io_error)
1663                 return;
1664 
1665         mutex_enter(&spa->spa_props_lock);       /* any mutex will do */
1666         if (spa->spa_claim_max_txg < zio->io_bp->blk_birth)
1667                 spa->spa_claim_max_txg = zio->io_bp->blk_birth;
1668         mutex_exit(&spa->spa_props_lock);
1669 }
1670 
1671 typedef struct spa_load_error {
1672         uint64_t        sle_meta_count;
1673         uint64_t        sle_data_count;
1674 } spa_load_error_t;
1675 
1676 static void
1677 spa_load_verify_done(zio_t *zio)
1678 {
1679         blkptr_t *bp = zio->io_bp;
1680         spa_load_error_t *sle = zio->io_private;
1681         dmu_object_type_t type = BP_GET_TYPE(bp);
1682         int error = zio->io_error;
1683 
1684         if (error) {
1685                 if ((BP_GET_LEVEL(bp) != 0 || DMU_OT_IS_METADATA(type)) &&
1686                     type != DMU_OT_INTENT_LOG)
1687                         atomic_add_64(&sle->sle_meta_count, 1);
1688                 else
1689                         atomic_add_64(&sle->sle_data_count, 1);
1690         }
1691         zio_data_buf_free(zio->io_data, zio->io_size);
1692 }
1693 
1694 /*ARGSUSED*/
1695 static int
1696 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1697     arc_buf_t *pbuf, const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1698 {
1699         if (bp != NULL) {
1700                 zio_t *rio = arg;
1701                 size_t size = BP_GET_PSIZE(bp);
1702                 void *data = zio_data_buf_alloc(size);
1703 
1704                 zio_nowait(zio_read(rio, spa, bp, data, size,
1705                     spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
1706                     ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
1707                     ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
1708         }
1709         return (0);
1710 }
1711 
1712 static int
1713 spa_load_verify(spa_t *spa)
1714 {
1715         zio_t *rio;
1716         spa_load_error_t sle = { 0 };
1717         zpool_rewind_policy_t policy;
1718         boolean_t verify_ok = B_FALSE;
1719         int error;
1720 
1721         zpool_get_rewind_policy(spa->spa_config, &policy);
1722 
1723         if (policy.zrp_request & ZPOOL_NEVER_REWIND)
1724                 return (0);
1725 
1726         rio = zio_root(spa, NULL, &sle,
1727             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1728 
1729         error = traverse_pool(spa, spa->spa_verify_min_txg,
1730             TRAVERSE_PRE | TRAVERSE_PREFETCH, spa_load_verify_cb, rio);
1731 
1732         (void) zio_wait(rio);
1733 
1734         spa->spa_load_meta_errors = sle.sle_meta_count;
1735         spa->spa_load_data_errors = sle.sle_data_count;
1736 
1737         if (!error && sle.sle_meta_count <= policy.zrp_maxmeta &&
1738             sle.sle_data_count <= policy.zrp_maxdata) {
1739                 int64_t loss = 0;
1740 
1741                 verify_ok = B_TRUE;
1742                 spa->spa_load_txg = spa->spa_uberblock.ub_txg;
1743                 spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
1744 
1745                 loss = spa->spa_last_ubsync_txg_ts - spa->spa_load_txg_ts;
1746                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1747                     ZPOOL_CONFIG_LOAD_TIME, spa->spa_load_txg_ts) == 0);
1748                 VERIFY(nvlist_add_int64(spa->spa_load_info,
1749                     ZPOOL_CONFIG_REWIND_TIME, loss) == 0);
1750                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1751                     ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count) == 0);
1752         } else {
1753                 spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
1754         }
1755 
1756         if (error) {
1757                 if (error != ENXIO && error != EIO)
1758                         error = EIO;
1759                 return (error);
1760         }
1761 
1762         return (verify_ok ? 0 : EIO);
1763 }
1764 
1765 /*
1766  * Find a value in the pool props object.
1767  */
1768 static void
1769 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
1770 {
1771         (void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
1772             zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
1773 }
1774 
1775 /*
1776  * Find a value in the pool directory object.
1777  */
1778 static int
1779 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val)
1780 {
1781         return (zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1782             name, sizeof (uint64_t), 1, val));
1783 }
1784 
1785 static int
1786 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
1787 {
1788         vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
1789         return (err);
1790 }
1791 
1792 /*
1793  * Fix up config after a partly-completed split.  This is done with the
1794  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
1795  * pool have that entry in their config, but only the splitting one contains
1796  * a list of all the guids of the vdevs that are being split off.
1797  *
1798  * This function determines what to do with that list: either rejoin
1799  * all the disks to the pool, or complete the splitting process.  To attempt
1800  * the rejoin, each disk that is offlined is marked online again, and
1801  * we do a reopen() call.  If the vdev label for every disk that was
1802  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
1803  * then we call vdev_split() on each disk, and complete the split.
1804  *
1805  * Otherwise we leave the config alone, with all the vdevs in place in
1806  * the original pool.
1807  */
1808 static void
1809 spa_try_repair(spa_t *spa, nvlist_t *config)
1810 {
1811         uint_t extracted;
1812         uint64_t *glist;
1813         uint_t i, gcount;
1814         nvlist_t *nvl;
1815         vdev_t **vd;
1816         boolean_t attempt_reopen;
1817 
1818         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
1819                 return;
1820 
1821         /* check that the config is complete */
1822         if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
1823             &glist, &gcount) != 0)
1824                 return;
1825 
1826         vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
1827 
1828         /* attempt to online all the vdevs & validate */
1829         attempt_reopen = B_TRUE;
1830         for (i = 0; i < gcount; i++) {
1831                 if (glist[i] == 0)      /* vdev is hole */
1832                         continue;
1833 
1834                 vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
1835                 if (vd[i] == NULL) {
1836                         /*
1837                          * Don't bother attempting to reopen the disks;
1838                          * just do the split.
1839                          */
1840                         attempt_reopen = B_FALSE;
1841                 } else {
1842                         /* attempt to re-online it */
1843                         vd[i]->vdev_offline = B_FALSE;
1844                 }
1845         }
1846 
1847         if (attempt_reopen) {
1848                 vdev_reopen(spa->spa_root_vdev);
1849 
1850                 /* check each device to see what state it's in */
1851                 for (extracted = 0, i = 0; i < gcount; i++) {
1852                         if (vd[i] != NULL &&
1853                             vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
1854                                 break;
1855                         ++extracted;
1856                 }
1857         }
1858 
1859         /*
1860          * If every disk has been moved to the new pool, or if we never
1861          * even attempted to look at them, then we split them off for
1862          * good.
1863          */
1864         if (!attempt_reopen || gcount == extracted) {
1865                 for (i = 0; i < gcount; i++)
1866                         if (vd[i] != NULL)
1867                                 vdev_split(vd[i]);
1868                 vdev_reopen(spa->spa_root_vdev);
1869         }
1870 
1871         kmem_free(vd, gcount * sizeof (vdev_t *));
1872 }
1873 
1874 static int
1875 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
1876     boolean_t mosconfig)
1877 {
1878         nvlist_t *config = spa->spa_config;
1879         char *ereport = FM_EREPORT_ZFS_POOL;
1880         char *comment;
1881         int error;
1882         uint64_t pool_guid;
1883         nvlist_t *nvl;
1884 
1885         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
1886                 return (EINVAL);
1887 
1888         ASSERT(spa->spa_comment == NULL);
1889         if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
1890                 spa->spa_comment = spa_strdup(comment);
1891 
1892         /*
1893          * Versioning wasn't explicitly added to the label until later, so if
1894          * it's not present treat it as the initial version.
1895          */
1896         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
1897             &spa->spa_ubsync.ub_version) != 0)
1898                 spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
1899 
1900         (void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
1901             &spa->spa_config_txg);
1902 
1903         if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
1904             spa_guid_exists(pool_guid, 0)) {
1905                 error = EEXIST;
1906         } else {
1907                 spa->spa_config_guid = pool_guid;
1908 
1909                 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT,
1910                     &nvl) == 0) {
1911                         VERIFY(nvlist_dup(nvl, &spa->spa_config_splitting,
1912                             KM_SLEEP) == 0);
1913                 }
1914 
1915                 nvlist_free(spa->spa_load_info);
1916                 spa->spa_load_info = fnvlist_alloc();
1917 
1918                 gethrestime(&spa->spa_loaded_ts);
1919                 error = spa_load_impl(spa, pool_guid, config, state, type,
1920                     mosconfig, &ereport);
1921         }
1922 
1923         spa->spa_minref = refcount_count(&spa->spa_refcount);
1924         if (error) {
1925                 if (error != EEXIST) {
1926                         spa->spa_loaded_ts.tv_sec = 0;
1927                         spa->spa_loaded_ts.tv_nsec = 0;
1928                 }
1929                 if (error != EBADF) {
1930                         zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
1931                 }
1932         }
1933         spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
1934         spa->spa_ena = 0;
1935 
1936         return (error);
1937 }
1938 
1939 /*
1940  * Load an existing storage pool, using the pool's builtin spa_config as a
1941  * source of configuration information.
1942  */
1943 static int
1944 spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config,
1945     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
1946     char **ereport)
1947 {
1948         int error = 0;
1949         nvlist_t *nvroot = NULL;
1950         nvlist_t *label;
1951         vdev_t *rvd;
1952         uberblock_t *ub = &spa->spa_uberblock;
1953         uint64_t children, config_cache_txg = spa->spa_config_txg;
1954         int orig_mode = spa->spa_mode;
1955         int parse;
1956         uint64_t obj;
1957         boolean_t missing_feat_write = B_FALSE;
1958 
1959         /*
1960          * If this is an untrusted config, access the pool in read-only mode.
1961          * This prevents things like resilvering recently removed devices.
1962          */
1963         if (!mosconfig)
1964                 spa->spa_mode = FREAD;
1965 
1966         ASSERT(MUTEX_HELD(&spa_namespace_lock));
1967 
1968         spa->spa_load_state = state;
1969 
1970         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot))
1971                 return (EINVAL);
1972 
1973         parse = (type == SPA_IMPORT_EXISTING ?
1974             VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
1975 
1976         /*
1977          * Create "The Godfather" zio to hold all async IOs
1978          */
1979         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
1980             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
1981 
1982         /*
1983          * Parse the configuration into a vdev tree.  We explicitly set the
1984          * value that will be returned by spa_version() since parsing the
1985          * configuration requires knowing the version number.
1986          */
1987         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1988         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, parse);
1989         spa_config_exit(spa, SCL_ALL, FTAG);
1990 
1991         if (error != 0)
1992                 return (error);
1993 
1994         ASSERT(spa->spa_root_vdev == rvd);
1995 
1996         if (type != SPA_IMPORT_ASSEMBLE) {
1997                 ASSERT(spa_guid(spa) == pool_guid);
1998         }
1999 
2000         /*
2001          * Try to open all vdevs, loading each label in the process.
2002          */
2003         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2004         error = vdev_open(rvd);
2005         spa_config_exit(spa, SCL_ALL, FTAG);
2006         if (error != 0)
2007                 return (error);
2008 
2009         /*
2010          * We need to validate the vdev labels against the configuration that
2011          * we have in hand, which is dependent on the setting of mosconfig. If
2012          * mosconfig is true then we're validating the vdev labels based on
2013          * that config.  Otherwise, we're validating against the cached config
2014          * (zpool.cache) that was read when we loaded the zfs module, and then
2015          * later we will recursively call spa_load() and validate against
2016          * the vdev config.
2017          *
2018          * If we're assembling a new pool that's been split off from an
2019          * existing pool, the labels haven't yet been updated so we skip
2020          * validation for now.
2021          */
2022         if (type != SPA_IMPORT_ASSEMBLE) {
2023                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2024                 error = vdev_validate(rvd, mosconfig);
2025                 spa_config_exit(spa, SCL_ALL, FTAG);
2026 
2027                 if (error != 0)
2028                         return (error);
2029 
2030                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2031                         return (ENXIO);
2032         }
2033 
2034         /*
2035          * Find the best uberblock.
2036          */
2037         vdev_uberblock_load(rvd, ub, &label);
2038 
2039         /*
2040          * If we weren't able to find a single valid uberblock, return failure.
2041          */
2042         if (ub->ub_txg == 0) {
2043                 nvlist_free(label);
2044                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
2045         }
2046 
2047         /*
2048          * If the pool has an unsupported version we can't open it.
2049          */
2050         if (!SPA_VERSION_IS_SUPPORTED(ub->ub_version)) {
2051                 nvlist_free(label);
2052                 return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
2053         }
2054 
2055         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2056                 nvlist_t *features;
2057 
2058                 /*
2059                  * If we weren't able to find what's necessary for reading the
2060                  * MOS in the label, return failure.
2061                  */
2062                 if (label == NULL || nvlist_lookup_nvlist(label,
2063                     ZPOOL_CONFIG_FEATURES_FOR_READ, &features) != 0) {
2064                         nvlist_free(label);
2065                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2066                             ENXIO));
2067                 }
2068 
2069                 /*
2070                  * Update our in-core representation with the definitive values
2071                  * from the label.
2072                  */
2073                 nvlist_free(spa->spa_label_features);
2074                 VERIFY(nvlist_dup(features, &spa->spa_label_features, 0) == 0);
2075         }
2076 
2077         nvlist_free(label);
2078 
2079         /*
2080          * Look through entries in the label nvlist's features_for_read. If
2081          * there is a feature listed there which we don't understand then we
2082          * cannot open a pool.
2083          */
2084         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2085                 nvlist_t *unsup_feat;
2086 
2087                 VERIFY(nvlist_alloc(&unsup_feat, NV_UNIQUE_NAME, KM_SLEEP) ==
2088                     0);
2089 
2090                 for (nvpair_t *nvp = nvlist_next_nvpair(spa->spa_label_features,
2091                     NULL); nvp != NULL;
2092                     nvp = nvlist_next_nvpair(spa->spa_label_features, nvp)) {
2093                         if (!zfeature_is_supported(nvpair_name(nvp))) {
2094                                 VERIFY(nvlist_add_string(unsup_feat,
2095                                     nvpair_name(nvp), "") == 0);
2096                         }
2097                 }
2098 
2099                 if (!nvlist_empty(unsup_feat)) {
2100                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
2101                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat) == 0);
2102                         nvlist_free(unsup_feat);
2103                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2104                             ENOTSUP));
2105                 }
2106 
2107                 nvlist_free(unsup_feat);
2108         }
2109 
2110         /*
2111          * If the vdev guid sum doesn't match the uberblock, we have an
2112          * incomplete configuration.  We first check to see if the pool
2113          * is aware of the complete config (i.e ZPOOL_CONFIG_VDEV_CHILDREN).
2114          * If it is, defer the vdev_guid_sum check till later so we
2115          * can handle missing vdevs.
2116          */
2117         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN,
2118             &children) != 0 && mosconfig && type != SPA_IMPORT_ASSEMBLE &&
2119             rvd->vdev_guid_sum != ub->ub_guid_sum)
2120                 return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
2121 
2122         if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
2123                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2124                 spa_try_repair(spa, config);
2125                 spa_config_exit(spa, SCL_ALL, FTAG);
2126                 nvlist_free(spa->spa_config_splitting);
2127                 spa->spa_config_splitting = NULL;
2128         }
2129 
2130         /*
2131          * Initialize internal SPA structures.
2132          */
2133         spa->spa_state = POOL_STATE_ACTIVE;
2134         spa->spa_ubsync = spa->spa_uberblock;
2135         spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
2136             TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
2137         spa->spa_first_txg = spa->spa_last_ubsync_txg ?
2138             spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
2139         spa->spa_claim_max_txg = spa->spa_first_txg;
2140         spa->spa_prev_software_version = ub->ub_software_version;
2141 
2142         error = dsl_pool_init(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
2143         if (error)
2144                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2145         spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
2146 
2147         if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object) != 0)
2148                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2149 
2150         if (spa_version(spa) >= SPA_VERSION_FEATURES) {
2151                 boolean_t missing_feat_read = B_FALSE;
2152                 nvlist_t *unsup_feat;
2153 
2154                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_READ,
2155                     &spa->spa_feat_for_read_obj) != 0) {
2156                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2157                 }
2158 
2159                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_WRITE,
2160                     &spa->spa_feat_for_write_obj) != 0) {
2161                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2162                 }
2163 
2164                 if (spa_dir_prop(spa, DMU_POOL_FEATURE_DESCRIPTIONS,
2165                     &spa->spa_feat_desc_obj) != 0) {
2166                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2167                 }
2168 
2169                 VERIFY(nvlist_alloc(&unsup_feat, NV_UNIQUE_NAME, KM_SLEEP) ==
2170                     0);
2171 
2172                 if (!feature_is_supported(spa->spa_meta_objset,
2173                     spa->spa_feat_for_read_obj, spa->spa_feat_desc_obj,
2174                     unsup_feat))
2175                         missing_feat_read = B_TRUE;
2176 
2177                 if (spa_writeable(spa) || state == SPA_LOAD_TRYIMPORT) {
2178                         if (!feature_is_supported(spa->spa_meta_objset,
2179                             spa->spa_feat_for_write_obj, spa->spa_feat_desc_obj,
2180                             unsup_feat))
2181                                 missing_feat_write = B_TRUE;
2182                 }
2183 
2184                 if (!nvlist_empty(unsup_feat)) {
2185                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
2186                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat) == 0);
2187                 }
2188 
2189                 nvlist_free(unsup_feat);
2190 
2191                 if (!missing_feat_read) {
2192                         fnvlist_add_boolean(spa->spa_load_info,
2193                             ZPOOL_CONFIG_CAN_RDONLY);
2194                 }
2195 
2196                 /*
2197                  * If the state is SPA_LOAD_TRYIMPORT, our objective is
2198                  * twofold: to determine whether the pool is available for
2199                  * import in read-write mode and (if it is not) whether the
2200                  * pool is available for import in read-only mode. If the pool
2201                  * is available for import in read-write mode, it is displayed
2202                  * as available in userland; if it is not available for import
2203                  * in read-only mode, it is displayed as unavailable in
2204                  * userland. If the pool is available for import in read-only
2205                  * mode but not read-write mode, it is displayed as unavailable
2206                  * in userland with a special note that the pool is actually
2207                  * available for open in read-only mode.
2208                  *
2209                  * As a result, if the state is SPA_LOAD_TRYIMPORT and we are
2210                  * missing a feature for write, we must first determine whether
2211                  * the pool can be opened read-only before returning to
2212                  * userland in order to know whether to display the
2213                  * abovementioned note.
2214                  */
2215                 if (missing_feat_read || (missing_feat_write &&
2216                     spa_writeable(spa))) {
2217                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2218                             ENOTSUP));
2219                 }
2220         }
2221 
2222         spa->spa_is_initializing = B_TRUE;
2223         error = dsl_pool_open(spa->spa_dsl_pool);
2224         spa->spa_is_initializing = B_FALSE;
2225         if (error != 0)
2226                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2227 
2228         if (!mosconfig) {
2229                 uint64_t hostid;
2230                 nvlist_t *policy = NULL, *nvconfig;
2231 
2232                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2233                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2234 
2235                 if (!spa_is_root(spa) && nvlist_lookup_uint64(nvconfig,
2236                     ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
2237                         char *hostname;
2238                         unsigned long myhostid = 0;
2239 
2240                         VERIFY(nvlist_lookup_string(nvconfig,
2241                             ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
2242 
2243 #ifdef  _KERNEL
2244                         myhostid = zone_get_hostid(NULL);
2245 #else   /* _KERNEL */
2246                         /*
2247                          * We're emulating the system's hostid in userland, so
2248                          * we can't use zone_get_hostid().
2249                          */
2250                         (void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
2251 #endif  /* _KERNEL */
2252                         if (hostid != 0 && myhostid != 0 &&
2253                             hostid != myhostid) {
2254                                 nvlist_free(nvconfig);
2255                                 cmn_err(CE_WARN, "pool '%s' could not be "
2256                                     "loaded as it was last accessed by "
2257                                     "another system (host: %s hostid: 0x%lx). "
2258                                     "See: http://illumos.org/msg/ZFS-8000-EY",
2259                                     spa_name(spa), hostname,
2260                                     (unsigned long)hostid);
2261                                 return (EBADF);
2262                         }
2263                 }
2264                 if (nvlist_lookup_nvlist(spa->spa_config,
2265                     ZPOOL_REWIND_POLICY, &policy) == 0)
2266                         VERIFY(nvlist_add_nvlist(nvconfig,
2267                             ZPOOL_REWIND_POLICY, policy) == 0);
2268 
2269                 spa_config_set(spa, nvconfig);
2270                 spa_unload(spa);
2271                 spa_deactivate(spa);
2272                 spa_activate(spa, orig_mode);
2273 
2274                 return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
2275         }
2276 
2277         if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj) != 0)
2278                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2279         error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
2280         if (error != 0)
2281                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2282 
2283         /*
2284          * Load the bit that tells us to use the new accounting function
2285          * (raid-z deflation).  If we have an older pool, this will not
2286          * be present.
2287          */
2288         error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate);
2289         if (error != 0 && error != ENOENT)
2290                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2291 
2292         error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
2293             &spa->spa_creation_version);
2294         if (error != 0 && error != ENOENT)
2295                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2296 
2297         /*
2298          * Load the persistent error log.  If we have an older pool, this will
2299          * not be present.
2300          */
2301         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last);
2302         if (error != 0 && error != ENOENT)
2303                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2304 
2305         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
2306             &spa->spa_errlog_scrub);
2307         if (error != 0 && error != ENOENT)
2308                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2309 
2310         /*
2311          * Load the history object.  If we have an older pool, this
2312          * will not be present.
2313          */
2314         error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history);
2315         if (error != 0 && error != ENOENT)
2316                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2317 
2318         /*
2319          * If we're assembling the pool from the split-off vdevs of
2320          * an existing pool, we don't want to attach the spares & cache
2321          * devices.
2322          */
2323 
2324         /*
2325          * Load any hot spares for this pool.
2326          */
2327         error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object);
2328         if (error != 0 && error != ENOENT)
2329                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2330         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2331                 ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
2332                 if (load_nvlist(spa, spa->spa_spares.sav_object,
2333                     &spa->spa_spares.sav_config) != 0)
2334                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2335 
2336                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2337                 spa_load_spares(spa);
2338                 spa_config_exit(spa, SCL_ALL, FTAG);
2339         } else if (error == 0) {
2340                 spa->spa_spares.sav_sync = B_TRUE;
2341         }
2342 
2343         /*
2344          * Load any level 2 ARC devices for this pool.
2345          */
2346         error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
2347             &spa->spa_l2cache.sav_object);
2348         if (error != 0 && error != ENOENT)
2349                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2350         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2351                 ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
2352                 if (load_nvlist(spa, spa->spa_l2cache.sav_object,
2353                     &spa->spa_l2cache.sav_config) != 0)
2354                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2355 
2356                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2357                 spa_load_l2cache(spa);
2358                 spa_config_exit(spa, SCL_ALL, FTAG);
2359         } else if (error == 0) {
2360                 spa->spa_l2cache.sav_sync = B_TRUE;
2361         }
2362 
2363         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2364 
2365         error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object);
2366         if (error && error != ENOENT)
2367                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2368 
2369         if (error == 0) {
2370                 uint64_t autoreplace;
2371 
2372                 spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
2373                 spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
2374                 spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
2375                 spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
2376                 spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
2377                 spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
2378                     &spa->spa_dedup_ditto);
2379 
2380                 spa->spa_autoreplace = (autoreplace != 0);
2381         }
2382 
2383         /*
2384          * If the 'autoreplace' property is set, then post a resource notifying
2385          * the ZFS DE that it should not issue any faults for unopenable
2386          * devices.  We also iterate over the vdevs, and post a sysevent for any
2387          * unopenable vdevs so that the normal autoreplace handler can take
2388          * over.
2389          */
2390         if (spa->spa_autoreplace && state != SPA_LOAD_TRYIMPORT) {
2391                 spa_check_removed(spa->spa_root_vdev);
2392                 /*
2393                  * For the import case, this is done in spa_import(), because
2394                  * at this point we're using the spare definitions from
2395                  * the MOS config, not necessarily from the userland config.
2396                  */
2397                 if (state != SPA_LOAD_IMPORT) {
2398                         spa_aux_check_removed(&spa->spa_spares);
2399                         spa_aux_check_removed(&spa->spa_l2cache);
2400                 }
2401         }
2402 
2403         /*
2404          * Load the vdev state for all toplevel vdevs.
2405          */
2406         vdev_load(rvd);
2407 
2408         /*
2409          * Propagate the leaf DTLs we just loaded all the way up the tree.
2410          */
2411         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2412         vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
2413         spa_config_exit(spa, SCL_ALL, FTAG);
2414 
2415         /*
2416          * Load the DDTs (dedup tables).
2417          */
2418         error = ddt_load(spa);
2419         if (error != 0)
2420                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2421 
2422         spa_update_dspace(spa);
2423 
2424         /*
2425          * Validate the config, using the MOS config to fill in any
2426          * information which might be missing.  If we fail to validate
2427          * the config then declare the pool unfit for use. If we're
2428          * assembling a pool from a split, the log is not transferred
2429          * over.
2430          */
2431         if (type != SPA_IMPORT_ASSEMBLE) {
2432                 nvlist_t *nvconfig;
2433 
2434                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2435                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2436 
2437                 if (!spa_config_valid(spa, nvconfig)) {
2438                         nvlist_free(nvconfig);
2439                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
2440                             ENXIO));
2441                 }
2442                 nvlist_free(nvconfig);
2443 
2444                 /*
2445                  * Now that we've validated the config, check the state of the
2446                  * root vdev.  If it can't be opened, it indicates one or
2447                  * more toplevel vdevs are faulted.
2448                  */
2449                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2450                         return (ENXIO);
2451 
2452                 if (spa_check_logs(spa)) {
2453                         *ereport = FM_EREPORT_ZFS_LOG_REPLAY;
2454                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG, ENXIO));
2455                 }
2456         }
2457 
2458         if (missing_feat_write) {
2459                 ASSERT(state == SPA_LOAD_TRYIMPORT);
2460 
2461                 /*
2462                  * At this point, we know that we can open the pool in
2463                  * read-only mode but not read-write mode. We now have enough
2464                  * information and can return to userland.
2465                  */
2466                 return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT, ENOTSUP));
2467         }
2468 
2469         /*
2470          * We've successfully opened the pool, verify that we're ready
2471          * to start pushing transactions.
2472          */
2473         if (state != SPA_LOAD_TRYIMPORT) {
2474                 if (error = spa_load_verify(spa))
2475                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2476                             error));
2477         }
2478 
2479         if (spa_writeable(spa) && (state == SPA_LOAD_RECOVER ||
2480             spa->spa_load_max_txg == UINT64_MAX)) {
2481                 dmu_tx_t *tx;
2482                 int need_update = B_FALSE;
2483 
2484                 ASSERT(state != SPA_LOAD_TRYIMPORT);
2485 
2486                 /*
2487                  * Claim log blocks that haven't been committed yet.
2488                  * This must all happen in a single txg.
2489                  * Note: spa_claim_max_txg is updated by spa_claim_notify(),
2490                  * invoked from zil_claim_log_block()'s i/o done callback.
2491                  * Price of rollback is that we abandon the log.
2492                  */
2493                 spa->spa_claiming = B_TRUE;
2494 
2495                 tx = dmu_tx_create_assigned(spa_get_dsl(spa),
2496                     spa_first_txg(spa));
2497                 (void) dmu_objset_find(spa_name(spa),
2498                     zil_claim, tx, DS_FIND_CHILDREN);
2499                 dmu_tx_commit(tx);
2500 
2501                 spa->spa_claiming = B_FALSE;
2502 
2503                 spa_set_log_state(spa, SPA_LOG_GOOD);
2504                 spa->spa_sync_on = B_TRUE;
2505                 txg_sync_start(spa->spa_dsl_pool);
2506 
2507                 /*
2508                  * Wait for all claims to sync.  We sync up to the highest
2509                  * claimed log block birth time so that claimed log blocks
2510                  * don't appear to be from the future.  spa_claim_max_txg
2511                  * will have been set for us by either zil_check_log_chain()
2512                  * (invoked from spa_check_logs()) or zil_claim() above.
2513                  */
2514                 txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
2515 
2516                 /*
2517                  * If the config cache is stale, or we have uninitialized
2518                  * metaslabs (see spa_vdev_add()), then update the config.
2519                  *
2520                  * If this is a verbatim import, trust the current
2521                  * in-core spa_config and update the disk labels.
2522                  */
2523                 if (config_cache_txg != spa->spa_config_txg ||
2524                     state == SPA_LOAD_IMPORT ||
2525                     state == SPA_LOAD_RECOVER ||
2526                     (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
2527                         need_update = B_TRUE;
2528 
2529                 for (int c = 0; c < rvd->vdev_children; c++)
2530                         if (rvd->vdev_child[c]->vdev_ms_array == 0)
2531                                 need_update = B_TRUE;
2532 
2533                 /*
2534                  * Update the config cache asychronously in case we're the
2535                  * root pool, in which case the config cache isn't writable yet.
2536                  */
2537                 if (need_update)
2538                         spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2539 
2540                 /*
2541                  * Check all DTLs to see if anything needs resilvering.
2542                  */
2543                 if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
2544                     vdev_resilver_needed(rvd, NULL, NULL))
2545                         spa_async_request(spa, SPA_ASYNC_RESILVER);
2546 
2547                 /*
2548                  * Log the fact that we booted up (so that we can detect if
2549                  * we rebooted in the middle of an operation).
2550                  */
2551                 spa_history_log_version(spa, "open");
2552 
2553                 /*
2554                  * Delete any inconsistent datasets.
2555                  */
2556                 (void) dmu_objset_find(spa_name(spa),
2557                     dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
2558 
2559                 /*
2560                  * Clean up any stale temporary dataset userrefs.
2561                  */
2562                 dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
2563         }
2564 
2565         return (0);
2566 }
2567 
2568 static int
2569 spa_load_retry(spa_t *spa, spa_load_state_t state, int mosconfig)
2570 {
2571         int mode = spa->spa_mode;
2572 
2573         spa_unload(spa);
2574         spa_deactivate(spa);
2575 
2576         spa->spa_load_max_txg--;
2577 
2578         spa_activate(spa, mode);
2579         spa_async_suspend(spa);
2580 
2581         return (spa_load(spa, state, SPA_IMPORT_EXISTING, mosconfig));
2582 }
2583 
2584 /*
2585  * If spa_load() fails this function will try loading prior txg's. If
2586  * 'state' is SPA_LOAD_RECOVER and one of these loads succeeds the pool
2587  * will be rewound to that txg. If 'state' is not SPA_LOAD_RECOVER this
2588  * function will not rewind the pool and will return the same error as
2589  * spa_load().
2590  */
2591 static int
2592 spa_load_best(spa_t *spa, spa_load_state_t state, int mosconfig,
2593     uint64_t max_request, int rewind_flags)
2594 {
2595         nvlist_t *loadinfo = NULL;
2596         nvlist_t *config = NULL;
2597         int load_error, rewind_error;
2598         uint64_t safe_rewind_txg;
2599         uint64_t min_txg;
2600 
2601         if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
2602                 spa->spa_load_max_txg = spa->spa_load_txg;
2603                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2604         } else {
2605                 spa->spa_load_max_txg = max_request;
2606         }
2607 
2608         load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING,
2609             mosconfig);
2610         if (load_error == 0)
2611                 return (0);
2612 
2613         if (spa->spa_root_vdev != NULL)
2614                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2615 
2616         spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
2617         spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
2618 
2619         if (rewind_flags & ZPOOL_NEVER_REWIND) {
2620                 nvlist_free(config);
2621                 return (load_error);
2622         }
2623 
2624         if (state == SPA_LOAD_RECOVER) {
2625                 /* Price of rolling back is discarding txgs, including log */
2626                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2627         } else {
2628                 /*
2629                  * If we aren't rolling back save the load info from our first
2630                  * import attempt so that we can restore it after attempting
2631                  * to rewind.
2632                  */
2633                 loadinfo = spa->spa_load_info;
2634                 spa->spa_load_info = fnvlist_alloc();
2635         }
2636 
2637         spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
2638         safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
2639         min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
2640             TXG_INITIAL : safe_rewind_txg;
2641 
2642         /*
2643          * Continue as long as we're finding errors, we're still within
2644          * the acceptable rewind range, and we're still finding uberblocks
2645          */
2646         while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
2647             spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
2648                 if (spa->spa_load_max_txg < safe_rewind_txg)
2649                         spa->spa_extreme_rewind = B_TRUE;
2650                 rewind_error = spa_load_retry(spa, state, mosconfig);
2651         }
2652 
2653         spa->spa_extreme_rewind = B_FALSE;
2654         spa->spa_load_max_txg = UINT64_MAX;
2655 
2656         if (config && (rewind_error || state != SPA_LOAD_RECOVER))
2657                 spa_config_set(spa, config);
2658 
2659         if (state == SPA_LOAD_RECOVER) {
2660                 ASSERT3P(loadinfo, ==, NULL);
2661                 return (rewind_error);
2662         } else {
2663                 /* Store the rewind info as part of the initial load info */
2664                 fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
2665                     spa->spa_load_info);
2666 
2667                 /* Restore the initial load info */
2668                 fnvlist_free(spa->spa_load_info);
2669                 spa->spa_load_info = loadinfo;
2670 
2671                 return (load_error);
2672         }
2673 }
2674 
2675 /*
2676  * Pool Open/Import
2677  *
2678  * The import case is identical to an open except that the configuration is sent
2679  * down from userland, instead of grabbed from the configuration cache.  For the
2680  * case of an open, the pool configuration will exist in the
2681  * POOL_STATE_UNINITIALIZED state.
2682  *
2683  * The stats information (gen/count/ustats) is used to gather vdev statistics at
2684  * the same time open the pool, without having to keep around the spa_t in some
2685  * ambiguous state.
2686  */
2687 static int
2688 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
2689     nvlist_t **config)
2690 {
2691         spa_t *spa;
2692         spa_load_state_t state = SPA_LOAD_OPEN;
2693         int error;
2694         int locked = B_FALSE;
2695 
2696         *spapp = NULL;
2697 
2698         /*
2699          * As disgusting as this is, we need to support recursive calls to this
2700          * function because dsl_dir_open() is called during spa_load(), and ends
2701          * up calling spa_open() again.  The real fix is to figure out how to
2702          * avoid dsl_dir_open() calling this in the first place.
2703          */
2704         if (mutex_owner(&spa_namespace_lock) != curthread) {
2705                 mutex_enter(&spa_namespace_lock);
2706                 locked = B_TRUE;
2707         }
2708 
2709         if ((spa = spa_lookup(pool)) == NULL) {
2710                 if (locked)
2711                         mutex_exit(&spa_namespace_lock);
2712                 return (ENOENT);
2713         }
2714 
2715         if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
2716                 zpool_rewind_policy_t policy;
2717 
2718                 zpool_get_rewind_policy(nvpolicy ? nvpolicy : spa->spa_config,
2719                     &policy);
2720                 if (policy.zrp_request & ZPOOL_DO_REWIND)
2721                         state = SPA_LOAD_RECOVER;
2722 
2723                 spa_activate(spa, spa_mode_global);
2724 
2725                 if (state != SPA_LOAD_RECOVER)
2726                         spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
2727 
2728                 error = spa_load_best(spa, state, B_FALSE, policy.zrp_txg,
2729                     policy.zrp_request);
2730 
2731                 if (error == EBADF) {
2732                         /*
2733                          * If vdev_validate() returns failure (indicated by
2734                          * EBADF), it indicates that one of the vdevs indicates
2735                          * that the pool has been exported or destroyed.  If
2736                          * this is the case, the config cache is out of sync and
2737                          * we should remove the pool from the namespace.
2738                          */
2739                         spa_unload(spa);
2740                         spa_deactivate(spa);
2741                         spa_config_sync(spa, B_TRUE, B_TRUE);
2742                         spa_remove(spa);
2743                         if (locked)
2744                                 mutex_exit(&spa_namespace_lock);
2745                         return (ENOENT);
2746                 }
2747 
2748                 if (error) {
2749                         /*
2750                          * We can't open the pool, but we still have useful
2751                          * information: the state of each vdev after the
2752                          * attempted vdev_open().  Return this to the user.
2753                          */
2754                         if (config != NULL && spa->spa_config) {
2755                                 VERIFY(nvlist_dup(spa->spa_config, config,
2756                                     KM_SLEEP) == 0);
2757                                 VERIFY(nvlist_add_nvlist(*config,
2758                                     ZPOOL_CONFIG_LOAD_INFO,
2759                                     spa->spa_load_info) == 0);
2760                         }
2761                         spa_unload(spa);
2762                         spa_deactivate(spa);
2763                         spa->spa_last_open_failed = error;
2764                         if (locked)
2765                                 mutex_exit(&spa_namespace_lock);
2766                         *spapp = NULL;
2767                         return (error);
2768                 }
2769         }
2770 
2771         spa_open_ref(spa, tag);
2772 
2773         if (config != NULL)
2774                 *config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2775 
2776         /*
2777          * If we've recovered the pool, pass back any information we
2778          * gathered while doing the load.
2779          */
2780         if (state == SPA_LOAD_RECOVER) {
2781                 VERIFY(nvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
2782                     spa->spa_load_info) == 0);
2783         }
2784 
2785         if (locked) {
2786                 spa->spa_last_open_failed = 0;
2787                 spa->spa_last_ubsync_txg = 0;
2788                 spa->spa_load_txg = 0;
2789                 mutex_exit(&spa_namespace_lock);
2790         }
2791 
2792         *spapp = spa;
2793 
2794         return (0);
2795 }
2796 
2797 int
2798 spa_open_rewind(const char *name, spa_t **spapp, void *tag, nvlist_t *policy,
2799     nvlist_t **config)
2800 {
2801         return (spa_open_common(name, spapp, tag, policy, config));
2802 }
2803 
2804 int
2805 spa_open(const char *name, spa_t **spapp, void *tag)
2806 {
2807         return (spa_open_common(name, spapp, tag, NULL, NULL));
2808 }
2809 
2810 /*
2811  * Lookup the given spa_t, incrementing the inject count in the process,
2812  * preventing it from being exported or destroyed.
2813  */
2814 spa_t *
2815 spa_inject_addref(char *name)
2816 {
2817         spa_t *spa;
2818 
2819         mutex_enter(&spa_namespace_lock);
2820         if ((spa = spa_lookup(name)) == NULL) {
2821                 mutex_exit(&spa_namespace_lock);
2822                 return (NULL);
2823         }
2824         spa->spa_inject_ref++;
2825         mutex_exit(&spa_namespace_lock);
2826 
2827         return (spa);
2828 }
2829 
2830 void
2831 spa_inject_delref(spa_t *spa)
2832 {
2833         mutex_enter(&spa_namespace_lock);
2834         spa->spa_inject_ref--;
2835         mutex_exit(&spa_namespace_lock);
2836 }
2837 
2838 /*
2839  * Add spares device information to the nvlist.
2840  */
2841 static void
2842 spa_add_spares(spa_t *spa, nvlist_t *config)
2843 {
2844         nvlist_t **spares;
2845         uint_t i, nspares;
2846         nvlist_t *nvroot;
2847         uint64_t guid;
2848         vdev_stat_t *vs;
2849         uint_t vsc;
2850         uint64_t pool;
2851 
2852         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
2853 
2854         if (spa->spa_spares.sav_count == 0)
2855                 return;
2856 
2857         VERIFY(nvlist_lookup_nvlist(config,
2858             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
2859         VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
2860             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
2861         if (nspares != 0) {
2862                 VERIFY(nvlist_add_nvlist_array(nvroot,
2863                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
2864                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
2865                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
2866 
2867                 /*
2868                  * Go through and find any spares which have since been
2869                  * repurposed as an active spare.  If this is the case, update
2870                  * their status appropriately.
2871                  */
2872                 for (i = 0; i < nspares; i++) {
2873                         VERIFY(nvlist_lookup_uint64(spares[i],
2874                             ZPOOL_CONFIG_GUID, &guid) == 0);
2875                         if (spa_spare_exists(guid, &pool, NULL) &&
2876                             pool != 0ULL) {
2877                                 VERIFY(nvlist_lookup_uint64_array(
2878                                     spares[i], ZPOOL_CONFIG_VDEV_STATS,
2879                                     (uint64_t **)&vs, &vsc) == 0);
2880                                 vs->vs_state = VDEV_STATE_CANT_OPEN;
2881                                 vs->vs_aux = VDEV_AUX_SPARED;
2882                         }
2883                 }
2884         }
2885 }
2886 
2887 /*
2888  * Add l2cache device information to the nvlist, including vdev stats.
2889  */
2890 static void
2891 spa_add_l2cache(spa_t *spa, nvlist_t *config)
2892 {
2893         nvlist_t **l2cache;
2894         uint_t i, j, nl2cache;
2895         nvlist_t *nvroot;
2896         uint64_t guid;
2897         vdev_t *vd;
2898         vdev_stat_t *vs;
2899         uint_t vsc;
2900 
2901         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
2902 
2903         if (spa->spa_l2cache.sav_count == 0)
2904                 return;
2905 
2906         VERIFY(nvlist_lookup_nvlist(config,
2907             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
2908         VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
2909             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
2910         if (nl2cache != 0) {
2911                 VERIFY(nvlist_add_nvlist_array(nvroot,
2912                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
2913                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
2914                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
2915 
2916                 /*
2917                  * Update level 2 cache device stats.
2918                  */
2919 
2920                 for (i = 0; i < nl2cache; i++) {
2921                         VERIFY(nvlist_lookup_uint64(l2cache[i],
2922                             ZPOOL_CONFIG_GUID, &guid) == 0);
2923 
2924                         vd = NULL;
2925                         for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
2926                                 if (guid ==
2927                                     spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
2928                                         vd = spa->spa_l2cache.sav_vdevs[j];
2929                                         break;
2930                                 }
2931                         }
2932                         ASSERT(vd != NULL);
2933 
2934                         VERIFY(nvlist_lookup_uint64_array(l2cache[i],
2935                             ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc)
2936                             == 0);
2937                         vdev_get_stats(vd, vs);
2938                 }
2939         }
2940 }
2941 
2942 static void
2943 spa_add_feature_stats(spa_t *spa, nvlist_t *config)
2944 {
2945         nvlist_t *features;
2946         zap_cursor_t zc;
2947         zap_attribute_t za;
2948 
2949         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
2950         VERIFY(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2951 
2952         if (spa->spa_feat_for_read_obj != 0) {
2953                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
2954                     spa->spa_feat_for_read_obj);
2955                     zap_cursor_retrieve(&zc, &za) == 0;
2956                     zap_cursor_advance(&zc)) {
2957                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
2958                             za.za_num_integers == 1);
2959                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
2960                             za.za_first_integer));
2961                 }
2962                 zap_cursor_fini(&zc);
2963         }
2964 
2965         if (spa->spa_feat_for_write_obj != 0) {
2966                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
2967                     spa->spa_feat_for_write_obj);
2968                     zap_cursor_retrieve(&zc, &za) == 0;
2969                     zap_cursor_advance(&zc)) {
2970                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
2971                             za.za_num_integers == 1);
2972                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
2973                             za.za_first_integer));
2974                 }
2975                 zap_cursor_fini(&zc);
2976         }
2977 
2978         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
2979             features) == 0);
2980         nvlist_free(features);
2981 }
2982 
2983 int
2984 spa_get_stats(const char *name, nvlist_t **config,
2985     char *altroot, size_t buflen)
2986 {
2987         int error;
2988         spa_t *spa;
2989 
2990         *config = NULL;
2991         error = spa_open_common(name, &spa, FTAG, NULL, config);
2992 
2993         if (spa != NULL) {
2994                 /*
2995                  * This still leaves a window of inconsistency where the spares
2996                  * or l2cache devices could change and the config would be
2997                  * self-inconsistent.
2998                  */
2999                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3000 
3001                 if (*config != NULL) {
3002                         uint64_t loadtimes[2];
3003 
3004                         loadtimes[0] = spa->spa_loaded_ts.tv_sec;
3005                         loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
3006                         VERIFY(nvlist_add_uint64_array(*config,
3007                             ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2) == 0);
3008 
3009                         VERIFY(nvlist_add_uint64(*config,
3010                             ZPOOL_CONFIG_ERRCOUNT,
3011                             spa_get_errlog_size(spa)) == 0);
3012 
3013                         if (spa_suspended(spa))
3014                                 VERIFY(nvlist_add_uint64(*config,
3015                                     ZPOOL_CONFIG_SUSPENDED,
3016                                     spa->spa_failmode) == 0);
3017 
3018                         spa_add_spares(spa, *config);
3019                         spa_add_l2cache(spa, *config);
3020                         spa_add_feature_stats(spa, *config);
3021                 }
3022         }
3023 
3024         /*
3025          * We want to get the alternate root even for faulted pools, so we cheat
3026          * and call spa_lookup() directly.
3027          */
3028         if (altroot) {
3029                 if (spa == NULL) {
3030                         mutex_enter(&spa_namespace_lock);
3031                         spa = spa_lookup(name);
3032                         if (spa)
3033                                 spa_altroot(spa, altroot, buflen);
3034                         else
3035                                 altroot[0] = '\0';
3036                         spa = NULL;
3037                         mutex_exit(&spa_namespace_lock);
3038                 } else {
3039                         spa_altroot(spa, altroot, buflen);
3040                 }
3041         }
3042 
3043         if (spa != NULL) {
3044                 spa_config_exit(spa, SCL_CONFIG, FTAG);
3045                 spa_close(spa, FTAG);
3046         }
3047 
3048         return (error);
3049 }
3050 
3051 /*
3052  * Validate that the auxiliary device array is well formed.  We must have an
3053  * array of nvlists, each which describes a valid leaf vdev.  If this is an
3054  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
3055  * specified, as long as they are well-formed.
3056  */
3057 static int
3058 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
3059     spa_aux_vdev_t *sav, const char *config, uint64_t version,
3060     vdev_labeltype_t label)
3061 {
3062         nvlist_t **dev;
3063         uint_t i, ndev;
3064         vdev_t *vd;
3065         int error;
3066 
3067         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3068 
3069         /*
3070          * It's acceptable to have no devs specified.
3071          */
3072         if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
3073                 return (0);
3074 
3075         if (ndev == 0)
3076                 return (EINVAL);
3077 
3078         /*
3079          * Make sure the pool is formatted with a version that supports this
3080          * device type.
3081          */
3082         if (spa_version(spa) < version)
3083                 return (ENOTSUP);
3084 
3085         /*
3086          * Set the pending device list so we correctly handle device in-use
3087          * checking.
3088          */
3089         sav->sav_pending = dev;
3090         sav->sav_npending = ndev;
3091 
3092         for (i = 0; i < ndev; i++) {
3093                 if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
3094                     mode)) != 0)
3095                         goto out;
3096 
3097                 if (!vd->vdev_ops->vdev_op_leaf) {
3098                         vdev_free(vd);
3099                         error = EINVAL;
3100                         goto out;
3101                 }
3102 
3103                 /*
3104                  * The L2ARC currently only supports disk devices in
3105                  * kernel context.  For user-level testing, we allow it.
3106                  */
3107 #ifdef _KERNEL
3108                 if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
3109                     strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
3110                         error = ENOTBLK;
3111                         vdev_free(vd);
3112                         goto out;
3113                 }
3114 #endif
3115                 vd->vdev_top = vd;
3116 
3117                 if ((error = vdev_open(vd)) == 0 &&
3118                     (error = vdev_label_init(vd, crtxg, label)) == 0) {
3119                         VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
3120                             vd->vdev_guid) == 0);
3121                 }
3122 
3123                 vdev_free(vd);
3124 
3125                 if (error &&
3126                     (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
3127                         goto out;
3128                 else
3129                         error = 0;
3130         }
3131 
3132 out:
3133         sav->sav_pending = NULL;
3134         sav->sav_npending = 0;
3135         return (error);
3136 }
3137 
3138 static int
3139 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
3140 {
3141         int error;
3142 
3143         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3144 
3145         if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3146             &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
3147             VDEV_LABEL_SPARE)) != 0) {
3148                 return (error);
3149         }
3150 
3151         return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3152             &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
3153             VDEV_LABEL_L2CACHE));
3154 }
3155 
3156 static void
3157 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
3158     const char *config)
3159 {
3160         int i;
3161 
3162         if (sav->sav_config != NULL) {
3163                 nvlist_t **olddevs;
3164                 uint_t oldndevs;
3165                 nvlist_t **newdevs;
3166 
3167                 /*
3168                  * Generate new dev list by concatentating with the
3169                  * current dev list.
3170                  */
3171                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
3172                     &olddevs, &oldndevs) == 0);
3173 
3174                 newdevs = kmem_alloc(sizeof (void *) *
3175                     (ndevs + oldndevs), KM_SLEEP);
3176                 for (i = 0; i < oldndevs; i++)
3177                         VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
3178                             KM_SLEEP) == 0);
3179                 for (i = 0; i < ndevs; i++)
3180                         VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
3181                             KM_SLEEP) == 0);
3182 
3183                 VERIFY(nvlist_remove(sav->sav_config, config,
3184                     DATA_TYPE_NVLIST_ARRAY) == 0);
3185 
3186                 VERIFY(nvlist_add_nvlist_array(sav->sav_config,
3187                     config, newdevs, ndevs + oldndevs) == 0);
3188                 for (i = 0; i < oldndevs + ndevs; i++)
3189                         nvlist_free(newdevs[i]);
3190                 kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
3191         } else {
3192                 /*
3193                  * Generate a new dev list.
3194                  */
3195                 VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
3196                     KM_SLEEP) == 0);
3197                 VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
3198                     devs, ndevs) == 0);
3199         }
3200 }
3201 
3202 /*
3203  * Stop and drop level 2 ARC devices
3204  */
3205 void
3206 spa_l2cache_drop(spa_t *spa)
3207 {
3208         vdev_t *vd;
3209         int i;
3210         spa_aux_vdev_t *sav = &spa->spa_l2cache;
3211 
3212         for (i = 0; i < sav->sav_count; i++) {
3213                 uint64_t pool;
3214 
3215                 vd = sav->sav_vdevs[i];
3216                 ASSERT(vd != NULL);
3217 
3218                 if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
3219                     pool != 0ULL && l2arc_vdev_present(vd))
3220                         l2arc_remove_vdev(vd);
3221         }
3222 }
3223 
3224 /*
3225  * Pool Creation
3226  */
3227 int
3228 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
3229     nvlist_t *zplprops)
3230 {
3231         spa_t *spa;
3232         char *altroot = NULL;
3233         vdev_t *rvd;
3234         dsl_pool_t *dp;
3235         dmu_tx_t *tx;
3236         int error = 0;
3237         uint64_t txg = TXG_INITIAL;
3238         nvlist_t **spares, **l2cache;
3239         uint_t nspares, nl2cache;
3240         uint64_t version, obj;
3241         boolean_t has_features;
3242 
3243         /*
3244          * If this pool already exists, return failure.
3245          */
3246         mutex_enter(&spa_namespace_lock);
3247         if (spa_lookup(pool) != NULL) {
3248                 mutex_exit(&spa_namespace_lock);
3249                 return (EEXIST);
3250         }
3251 
3252         /*
3253          * Allocate a new spa_t structure.
3254          */
3255         (void) nvlist_lookup_string(props,
3256             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3257         spa = spa_add(pool, NULL, altroot);
3258         spa_activate(spa, spa_mode_global);
3259 
3260         if (props && (error = spa_prop_validate(spa, props))) {
3261                 spa_deactivate(spa);
3262                 spa_remove(spa);
3263                 mutex_exit(&spa_namespace_lock);
3264                 return (error);
3265         }
3266 
3267         has_features = B_FALSE;
3268         for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
3269             elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
3270                 if (zpool_prop_feature(nvpair_name(elem)))
3271                         has_features = B_TRUE;
3272         }
3273 
3274         if (has_features || nvlist_lookup_uint64(props,
3275             zpool_prop_to_name(ZPOOL_PROP_VERSION), &version) != 0) {
3276                 version = SPA_VERSION;
3277         }
3278         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
3279 
3280         spa->spa_first_txg = txg;
3281         spa->spa_uberblock.ub_txg = txg - 1;
3282         spa->spa_uberblock.ub_version = version;
3283         spa->spa_ubsync = spa->spa_uberblock;
3284 
3285         /*
3286          * Create "The Godfather" zio to hold all async IOs
3287          */
3288         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
3289             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
3290 
3291         /*
3292          * Create the root vdev.
3293          */
3294         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3295 
3296         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
3297 
3298         ASSERT(error != 0 || rvd != NULL);
3299         ASSERT(error != 0 || spa->spa_root_vdev == rvd);
3300 
3301         if (error == 0 && !zfs_allocatable_devs(nvroot))
3302                 error = EINVAL;
3303 
3304         if (error == 0 &&
3305             (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
3306             (error = spa_validate_aux(spa, nvroot, txg,
3307             VDEV_ALLOC_ADD)) == 0) {
3308                 for (int c = 0; c < rvd->vdev_children; c++) {
3309                         vdev_metaslab_set_size(rvd->vdev_child[c]);
3310                         vdev_expand(rvd->vdev_child[c], txg);
3311                 }
3312         }
3313 
3314         spa_config_exit(spa, SCL_ALL, FTAG);
3315 
3316         if (error != 0) {
3317                 spa_unload(spa);
3318                 spa_deactivate(spa);
3319                 spa_remove(spa);
3320                 mutex_exit(&spa_namespace_lock);
3321                 return (error);
3322         }
3323 
3324         /*
3325          * Get the list of spares, if specified.
3326          */
3327         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3328             &spares, &nspares) == 0) {
3329                 VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
3330                     KM_SLEEP) == 0);
3331                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3332                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3333                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3334                 spa_load_spares(spa);
3335                 spa_config_exit(spa, SCL_ALL, FTAG);
3336                 spa->spa_spares.sav_sync = B_TRUE;
3337         }
3338 
3339         /*
3340          * Get the list of level 2 cache devices, if specified.
3341          */
3342         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3343             &l2cache, &nl2cache) == 0) {
3344                 VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3345                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
3346                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3347                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3348                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3349                 spa_load_l2cache(spa);
3350                 spa_config_exit(spa, SCL_ALL, FTAG);
3351                 spa->spa_l2cache.sav_sync = B_TRUE;
3352         }
3353 
3354         spa->spa_is_initializing = B_TRUE;
3355         spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
3356         spa->spa_meta_objset = dp->dp_meta_objset;
3357         spa->spa_is_initializing = B_FALSE;
3358 
3359         /*
3360          * Create DDTs (dedup tables).
3361          */
3362         ddt_create(spa);
3363 
3364         spa_update_dspace(spa);
3365 
3366         tx = dmu_tx_create_assigned(dp, txg);
3367 
3368         /*
3369          * Create the pool config object.
3370          */
3371         spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
3372             DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
3373             DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
3374 
3375         if (zap_add(spa->spa_meta_objset,
3376             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
3377             sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
3378                 cmn_err(CE_PANIC, "failed to add pool config");
3379         }
3380 
3381         if (spa_version(spa) >= SPA_VERSION_FEATURES)
3382                 spa_feature_create_zap_objects(spa, tx);
3383 
3384         if (zap_add(spa->spa_meta_objset,
3385             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
3386             sizeof (uint64_t), 1, &version, tx) != 0) {
3387                 cmn_err(CE_PANIC, "failed to add pool version");
3388         }
3389 
3390         /* Newly created pools with the right version are always deflated. */
3391         if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
3392                 spa->spa_deflate = TRUE;
3393                 if (zap_add(spa->spa_meta_objset,
3394                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
3395                     sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
3396                         cmn_err(CE_PANIC, "failed to add deflate");
3397                 }
3398         }
3399 
3400         /*
3401          * Create the deferred-free bpobj.  Turn off compression
3402          * because sync-to-convergence takes longer if the blocksize
3403          * keeps changing.
3404          */
3405         obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
3406         dmu_object_set_compress(spa->spa_meta_objset, obj,
3407             ZIO_COMPRESS_OFF, tx);
3408         if (zap_add(spa->spa_meta_objset,
3409             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
3410             sizeof (uint64_t), 1, &obj, tx) != 0) {
3411                 cmn_err(CE_PANIC, "failed to add bpobj");
3412         }
3413         VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
3414             spa->spa_meta_objset, obj));
3415 
3416         /*
3417          * Create the pool's history object.
3418          */
3419         if (version >= SPA_VERSION_ZPOOL_HISTORY)
3420                 spa_history_create_obj(spa, tx);
3421 
3422         /*
3423          * Set pool properties.
3424          */
3425         spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
3426         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
3427         spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
3428         spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
3429 
3430         if (props != NULL) {
3431                 spa_configfile_set(spa, props, B_FALSE);
3432                 spa_sync_props(spa, props, tx);
3433         }
3434 
3435         dmu_tx_commit(tx);
3436 
3437         spa->spa_sync_on = B_TRUE;
3438         txg_sync_start(spa->spa_dsl_pool);
3439 
3440         /*
3441          * We explicitly wait for the first transaction to complete so that our
3442          * bean counters are appropriately updated.
3443          */
3444         txg_wait_synced(spa->spa_dsl_pool, txg);
3445 
3446         spa_config_sync(spa, B_FALSE, B_TRUE);
3447 
3448         spa_history_log_version(spa, "create");
3449 
3450         spa->spa_minref = refcount_count(&spa->spa_refcount);
3451 
3452         mutex_exit(&spa_namespace_lock);
3453 
3454         return (0);
3455 }
3456 
3457 #ifdef _KERNEL
3458 /*
3459  * Get the root pool information from the root disk, then import the root pool
3460  * during the system boot up time.
3461  */
3462 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
3463 
3464 static nvlist_t *
3465 spa_generate_rootconf(char *devpath, char *devid, uint64_t *guid)
3466 {
3467         nvlist_t *config;
3468         nvlist_t *nvtop, *nvroot;
3469         uint64_t pgid;
3470 
3471         if (vdev_disk_read_rootlabel(devpath, devid, &config) != 0)
3472                 return (NULL);
3473 
3474         /*
3475          * Add this top-level vdev to the child array.
3476          */
3477         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3478             &nvtop) == 0);
3479         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
3480             &pgid) == 0);
3481         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, guid) == 0);
3482 
3483         /*
3484          * Put this pool's top-level vdevs into a root vdev.
3485          */
3486         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3487         VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
3488             VDEV_TYPE_ROOT) == 0);
3489         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
3490         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
3491         VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
3492             &nvtop, 1) == 0);
3493 
3494         /*
3495          * Replace the existing vdev_tree with the new root vdev in
3496          * this pool's configuration (remove the old, add the new).
3497          */
3498         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
3499         nvlist_free(nvroot);
3500         return (config);
3501 }
3502 
3503 /*
3504  * Walk the vdev tree and see if we can find a device with "better"
3505  * configuration. A configuration is "better" if the label on that
3506  * device has a more recent txg.
3507  */
3508 static void
3509 spa_alt_rootvdev(vdev_t *vd, vdev_t **avd, uint64_t *txg)
3510 {
3511         for (int c = 0; c < vd->vdev_children; c++)
3512                 spa_alt_rootvdev(vd->vdev_child[c], avd, txg);
3513 
3514         if (vd->vdev_ops->vdev_op_leaf) {
3515                 nvlist_t *label;
3516                 uint64_t label_txg;
3517 
3518                 if (vdev_disk_read_rootlabel(vd->vdev_physpath, vd->vdev_devid,
3519                     &label) != 0)
3520                         return;
3521 
3522                 VERIFY(nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
3523                     &label_txg) == 0);
3524 
3525                 /*
3526                  * Do we have a better boot device?
3527                  */
3528                 if (label_txg > *txg) {
3529                         *txg = label_txg;
3530                         *avd = vd;
3531                 }
3532                 nvlist_free(label);
3533         }
3534 }
3535 
3536 /*
3537  * Import a root pool.
3538  *
3539  * For x86. devpath_list will consist of devid and/or physpath name of
3540  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
3541  * The GRUB "findroot" command will return the vdev we should boot.
3542  *
3543  * For Sparc, devpath_list consists the physpath name of the booting device
3544  * no matter the rootpool is a single device pool or a mirrored pool.
3545  * e.g.
3546  *      "/pci@1f,0/ide@d/disk@0,0:a"
3547  */
3548 int
3549 spa_import_rootpool(char *devpath, char *devid)
3550 {
3551         spa_t *spa;
3552         vdev_t *rvd, *bvd, *avd = NULL;
3553         nvlist_t *config, *nvtop;
3554         uint64_t guid, txg;
3555         char *pname;
3556         int error;
3557 
3558         /*
3559          * Read the label from the boot device and generate a configuration.
3560          */
3561         config = spa_generate_rootconf(devpath, devid, &guid);
3562 #if defined(_OBP) && defined(_KERNEL)
3563         if (config == NULL) {
3564                 if (strstr(devpath, "/iscsi/ssd") != NULL) {
3565                         /* iscsi boot */
3566                         get_iscsi_bootpath_phy(devpath);
3567                         config = spa_generate_rootconf(devpath, devid, &guid);
3568                 }
3569         }
3570 #endif
3571         if (config == NULL) {
3572                 cmn_err(CE_NOTE, "Cannot read the pool label from '%s'",
3573                     devpath);
3574                 return (EIO);
3575         }
3576 
3577         VERIFY(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
3578             &pname) == 0);
3579         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
3580 
3581         mutex_enter(&spa_namespace_lock);
3582         if ((spa = spa_lookup(pname)) != NULL) {
3583                 /*
3584                  * Remove the existing root pool from the namespace so that we
3585                  * can replace it with the correct config we just read in.
3586                  */
3587                 spa_remove(spa);
3588         }
3589 
3590         spa = spa_add(pname, config, NULL);
3591         spa->spa_is_root = B_TRUE;
3592         spa->spa_import_flags = ZFS_IMPORT_VERBATIM;
3593 
3594         /*
3595          * Build up a vdev tree based on the boot device's label config.
3596          */
3597         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3598             &nvtop) == 0);
3599         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3600         error = spa_config_parse(spa, &rvd, nvtop, NULL, 0,
3601             VDEV_ALLOC_ROOTPOOL);
3602         spa_config_exit(spa, SCL_ALL, FTAG);
3603         if (error) {
3604                 mutex_exit(&spa_namespace_lock);
3605                 nvlist_free(config);
3606                 cmn_err(CE_NOTE, "Can not parse the config for pool '%s'",
3607                     pname);
3608                 return (error);
3609         }
3610 
3611         /*
3612          * Get the boot vdev.
3613          */
3614         if ((bvd = vdev_lookup_by_guid(rvd, guid)) == NULL) {
3615                 cmn_err(CE_NOTE, "Can not find the boot vdev for guid %llu",
3616                     (u_longlong_t)guid);
3617                 error = ENOENT;
3618                 goto out;
3619         }
3620 
3621         /*
3622          * Determine if there is a better boot device.
3623          */
3624         avd = bvd;
3625         spa_alt_rootvdev(rvd, &avd, &txg);
3626         if (avd != bvd) {
3627                 cmn_err(CE_NOTE, "The boot device is 'degraded'. Please "
3628                     "try booting from '%s'", avd->vdev_path);
3629                 error = EINVAL;
3630                 goto out;
3631         }
3632 
3633         /*
3634          * If the boot device is part of a spare vdev then ensure that
3635          * we're booting off the active spare.
3636          */
3637         if (bvd->vdev_parent->vdev_ops == &vdev_spare_ops &&
3638             !bvd->vdev_isspare) {
3639                 cmn_err(CE_NOTE, "The boot device is currently spared. Please "
3640                     "try booting from '%s'",
3641                     bvd->vdev_parent->
3642                     vdev_child[bvd->vdev_parent->vdev_children - 1]->vdev_path);
3643                 error = EINVAL;
3644                 goto out;
3645         }
3646 
3647         error = 0;
3648 out:
3649         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3650         vdev_free(rvd);
3651         spa_config_exit(spa, SCL_ALL, FTAG);
3652         mutex_exit(&spa_namespace_lock);
3653 
3654         nvlist_free(config);
3655         return (error);
3656 }
3657 
3658 #endif
3659 
3660 /*
3661  * Import a non-root pool into the system.
3662  */
3663 int
3664 spa_import(const char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
3665 {
3666         spa_t *spa;
3667         char *altroot = NULL;
3668         spa_load_state_t state = SPA_LOAD_IMPORT;
3669         zpool_rewind_policy_t policy;
3670         uint64_t mode = spa_mode_global;
3671         uint64_t readonly = B_FALSE;
3672         int error;
3673         nvlist_t *nvroot;
3674         nvlist_t **spares, **l2cache;
3675         uint_t nspares, nl2cache;
3676 
3677         /*
3678          * If a pool with this name exists, return failure.
3679          */
3680         mutex_enter(&spa_namespace_lock);
3681         if (spa_lookup(pool) != NULL) {
3682                 mutex_exit(&spa_namespace_lock);
3683                 return (EEXIST);
3684         }
3685 
3686         /*
3687          * Create and initialize the spa structure.
3688          */
3689         (void) nvlist_lookup_string(props,
3690             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3691         (void) nvlist_lookup_uint64(props,
3692             zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
3693         if (readonly)
3694                 mode = FREAD;
3695         spa = spa_add(pool, config, altroot);
3696         spa->spa_import_flags = flags;
3697 
3698         /*
3699          * Verbatim import - Take a pool and insert it into the namespace
3700          * as if it had been loaded at boot.
3701          */
3702         if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
3703                 if (props != NULL)
3704                         spa_configfile_set(spa, props, B_FALSE);
3705 
3706                 spa_config_sync(spa, B_FALSE, B_TRUE);
3707 
3708                 mutex_exit(&spa_namespace_lock);
3709                 spa_history_log_version(spa, "import");
3710 
3711                 return (0);
3712         }
3713 
3714         spa_activate(spa, mode);
3715 
3716         /*
3717          * Don't start async tasks until we know everything is healthy.
3718          */
3719         spa_async_suspend(spa);
3720 
3721         zpool_get_rewind_policy(config, &policy);
3722         if (policy.zrp_request & ZPOOL_DO_REWIND)
3723                 state = SPA_LOAD_RECOVER;
3724 
3725         /*
3726          * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
3727          * because the user-supplied config is actually the one to trust when
3728          * doing an import.
3729          */
3730         if (state != SPA_LOAD_RECOVER)
3731                 spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
3732 
3733         error = spa_load_best(spa, state, B_TRUE, policy.zrp_txg,
3734             policy.zrp_request);
3735 
3736         /*
3737          * Propagate anything learned while loading the pool and pass it
3738          * back to caller (i.e. rewind info, missing devices, etc).
3739          */
3740         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
3741             spa->spa_load_info) == 0);
3742 
3743         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3744         /*
3745          * Toss any existing sparelist, as it doesn't have any validity
3746          * anymore, and conflicts with spa_has_spare().
3747          */
3748         if (spa->spa_spares.sav_config) {
3749                 nvlist_free(spa->spa_spares.sav_config);
3750                 spa->spa_spares.sav_config = NULL;
3751                 spa_load_spares(spa);
3752         }
3753         if (spa->spa_l2cache.sav_config) {
3754                 nvlist_free(spa->spa_l2cache.sav_config);
3755                 spa->spa_l2cache.sav_config = NULL;
3756                 spa_load_l2cache(spa);
3757         }
3758 
3759         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3760             &nvroot) == 0);
3761         if (error == 0)
3762                 error = spa_validate_aux(spa, nvroot, -1ULL,
3763                     VDEV_ALLOC_SPARE);
3764         if (error == 0)
3765                 error = spa_validate_aux(spa, nvroot, -1ULL,
3766                     VDEV_ALLOC_L2CACHE);
3767         spa_config_exit(spa, SCL_ALL, FTAG);
3768 
3769         if (props != NULL)
3770                 spa_configfile_set(spa, props, B_FALSE);
3771 
3772         if (error != 0 || (props && spa_writeable(spa) &&
3773             (error = spa_prop_set(spa, props)))) {
3774                 spa_unload(spa);
3775                 spa_deactivate(spa);
3776                 spa_remove(spa);
3777                 mutex_exit(&spa_namespace_lock);
3778                 return (error);
3779         }
3780 
3781         spa_async_resume(spa);
3782 
3783         /*
3784          * Override any spares and level 2 cache devices as specified by
3785          * the user, as these may have correct device names/devids, etc.
3786          */
3787         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3788             &spares, &nspares) == 0) {
3789                 if (spa->spa_spares.sav_config)
3790                         VERIFY(nvlist_remove(spa->spa_spares.sav_config,
3791                             ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
3792                 else
3793                         VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
3794                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
3795                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3796                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3797                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3798                 spa_load_spares(spa);
3799                 spa_config_exit(spa, SCL_ALL, FTAG);
3800                 spa->spa_spares.sav_sync = B_TRUE;
3801         }
3802         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3803             &l2cache, &nl2cache) == 0) {
3804                 if (spa->spa_l2cache.sav_config)
3805                         VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
3806                             ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
3807                 else
3808                         VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3809                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
3810                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3811                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3812                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3813                 spa_load_l2cache(spa);
3814                 spa_config_exit(spa, SCL_ALL, FTAG);
3815                 spa->spa_l2cache.sav_sync = B_TRUE;
3816         }
3817 
3818         /*
3819          * Check for any removed devices.
3820          */
3821         if (spa->spa_autoreplace) {
3822                 spa_aux_check_removed(&spa->spa_spares);
3823                 spa_aux_check_removed(&spa->spa_l2cache);
3824         }
3825 
3826         if (spa_writeable(spa)) {
3827                 /*
3828                  * Update the config cache to include the newly-imported pool.
3829                  */
3830                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
3831         }
3832 
3833         /*
3834          * It's possible that the pool was expanded while it was exported.
3835          * We kick off an async task to handle this for us.
3836          */
3837         spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
3838 
3839         mutex_exit(&spa_namespace_lock);
3840         spa_history_log_version(spa, "import");
3841 
3842         return (0);
3843 }
3844 
3845 nvlist_t *
3846 spa_tryimport(nvlist_t *tryconfig)
3847 {
3848         nvlist_t *config = NULL;
3849         char *poolname;
3850         spa_t *spa;
3851         uint64_t state;
3852         int error;
3853 
3854         if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
3855                 return (NULL);
3856 
3857         if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
3858                 return (NULL);
3859 
3860         /*
3861          * Create and initialize the spa structure.
3862          */
3863         mutex_enter(&spa_namespace_lock);
3864         spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
3865         spa_activate(spa, FREAD);
3866 
3867         /*
3868          * Pass off the heavy lifting to spa_load().
3869          * Pass TRUE for mosconfig because the user-supplied config
3870          * is actually the one to trust when doing an import.
3871          */
3872         error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING, B_TRUE);
3873 
3874         /*
3875          * If 'tryconfig' was at least parsable, return the current config.
3876          */
3877         if (spa->spa_root_vdev != NULL) {
3878                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
3879                 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
3880                     poolname) == 0);
3881                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
3882                     state) == 0);
3883                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
3884                     spa->spa_uberblock.ub_timestamp) == 0);
3885                 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
3886                     spa->spa_load_info) == 0);
3887 
3888                 /*
3889                  * If the bootfs property exists on this pool then we
3890                  * copy it out so that external consumers can tell which
3891                  * pools are bootable.
3892                  */
3893                 if ((!error || error == EEXIST) && spa->spa_bootfs) {
3894                         char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
3895 
3896                         /*
3897                          * We have to play games with the name since the
3898                          * pool was opened as TRYIMPORT_NAME.
3899                          */
3900                         if (dsl_dsobj_to_dsname(spa_name(spa),
3901                             spa->spa_bootfs, tmpname) == 0) {
3902                                 char *cp;
3903                                 char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
3904 
3905                                 cp = strchr(tmpname, '/');
3906                                 if (cp == NULL) {
3907                                         (void) strlcpy(dsname, tmpname,
3908                                             MAXPATHLEN);
3909                                 } else {
3910                                         (void) snprintf(dsname, MAXPATHLEN,
3911                                             "%s/%s", poolname, ++cp);
3912                                 }
3913                                 VERIFY(nvlist_add_string(config,
3914                                     ZPOOL_CONFIG_BOOTFS, dsname) == 0);
3915                                 kmem_free(dsname, MAXPATHLEN);
3916                         }
3917                         kmem_free(tmpname, MAXPATHLEN);
3918                 }
3919 
3920                 /*
3921                  * Add the list of hot spares and level 2 cache devices.
3922                  */
3923                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3924                 spa_add_spares(spa, config);
3925                 spa_add_l2cache(spa, config);
3926                 spa_config_exit(spa, SCL_CONFIG, FTAG);
3927         }
3928 
3929         spa_unload(spa);
3930         spa_deactivate(spa);
3931         spa_remove(spa);
3932         mutex_exit(&spa_namespace_lock);
3933 
3934         return (config);
3935 }
3936 
3937 /*
3938  * Pool export/destroy
3939  *
3940  * The act of destroying or exporting a pool is very simple.  We make sure there
3941  * is no more pending I/O and any references to the pool are gone.  Then, we
3942  * update the pool state and sync all the labels to disk, removing the
3943  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
3944  * we don't sync the labels or remove the configuration cache.
3945  */
3946 static int
3947 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
3948     boolean_t force, boolean_t hardforce)
3949 {
3950         spa_t *spa;
3951 
3952         if (oldconfig)
3953                 *oldconfig = NULL;
3954 
3955         if (!(spa_mode_global & FWRITE))
3956                 return (EROFS);
3957 
3958         mutex_enter(&spa_namespace_lock);
3959         if ((spa = spa_lookup(pool)) == NULL) {
3960                 mutex_exit(&spa_namespace_lock);
3961                 return (ENOENT);
3962         }
3963 
3964         /*
3965          * Put a hold on the pool, drop the namespace lock, stop async tasks,
3966          * reacquire the namespace lock, and see if we can export.
3967          */
3968         spa_open_ref(spa, FTAG);
3969         mutex_exit(&spa_namespace_lock);
3970         spa_async_suspend(spa);
3971         mutex_enter(&spa_namespace_lock);
3972         spa_close(spa, FTAG);
3973 
3974         /*
3975          * The pool will be in core if it's openable,
3976          * in which case we can modify its state.
3977          */
3978         if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
3979                 /*
3980                  * Objsets may be open only because they're dirty, so we
3981                  * have to force it to sync before checking spa_refcnt.
3982                  */
3983                 txg_wait_synced(spa->spa_dsl_pool, 0);
3984 
3985                 /*
3986                  * A pool cannot be exported or destroyed if there are active
3987                  * references.  If we are resetting a pool, allow references by
3988                  * fault injection handlers.
3989                  */
3990                 if (!spa_refcount_zero(spa) ||
3991                     (spa->spa_inject_ref != 0 &&
3992                     new_state != POOL_STATE_UNINITIALIZED)) {
3993                         spa_async_resume(spa);
3994                         mutex_exit(&spa_namespace_lock);
3995                         return (EBUSY);
3996                 }
3997 
3998                 /*
3999                  * A pool cannot be exported if it has an active shared spare.
4000                  * This is to prevent other pools stealing the active spare
4001                  * from an exported pool. At user's own will, such pool can
4002                  * be forcedly exported.
4003                  */
4004                 if (!force && new_state == POOL_STATE_EXPORTED &&
4005                     spa_has_active_shared_spare(spa)) {
4006                         spa_async_resume(spa);
4007                         mutex_exit(&spa_namespace_lock);
4008                         return (EXDEV);
4009                 }
4010 
4011                 /*
4012                  * We want this to be reflected on every label,
4013                  * so mark them all dirty.  spa_unload() will do the
4014                  * final sync that pushes these changes out.
4015                  */
4016                 if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
4017                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4018                         spa->spa_state = new_state;
4019                         spa->spa_final_txg = spa_last_synced_txg(spa) +
4020                             TXG_DEFER_SIZE + 1;
4021                         vdev_config_dirty(spa->spa_root_vdev);
4022                         spa_config_exit(spa, SCL_ALL, FTAG);
4023                 }
4024         }
4025 
4026         spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
4027 
4028         if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
4029                 spa_unload(spa);
4030                 spa_deactivate(spa);
4031         }
4032 
4033         if (oldconfig && spa->spa_config)
4034                 VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
4035 
4036         if (new_state != POOL_STATE_UNINITIALIZED) {
4037                 if (!hardforce)
4038                         spa_config_sync(spa, B_TRUE, B_TRUE);
4039                 spa_remove(spa);
4040         }
4041         mutex_exit(&spa_namespace_lock);
4042 
4043         return (0);
4044 }
4045 
4046 /*
4047  * Destroy a storage pool.
4048  */
4049 int
4050 spa_destroy(char *pool)
4051 {
4052         return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
4053             B_FALSE, B_FALSE));
4054 }
4055 
4056 /*
4057  * Export a storage pool.
4058  */
4059 int
4060 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
4061     boolean_t hardforce)
4062 {
4063         return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
4064             force, hardforce));
4065 }
4066 
4067 /*
4068  * Similar to spa_export(), this unloads the spa_t without actually removing it
4069  * from the namespace in any way.
4070  */
4071 int
4072 spa_reset(char *pool)
4073 {
4074         return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
4075             B_FALSE, B_FALSE));
4076 }
4077 
4078 /*
4079  * ==========================================================================
4080  * Device manipulation
4081  * ==========================================================================
4082  */
4083 
4084 /*
4085  * Add a device to a storage pool.
4086  */
4087 int
4088 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
4089 {
4090         uint64_t txg, id;
4091         int error;
4092         vdev_t *rvd = spa->spa_root_vdev;
4093         vdev_t *vd, *tvd;
4094         nvlist_t **spares, **l2cache;
4095         uint_t nspares, nl2cache;
4096 
4097         ASSERT(spa_writeable(spa));
4098 
4099         txg = spa_vdev_enter(spa);
4100 
4101         if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
4102             VDEV_ALLOC_ADD)) != 0)
4103                 return (spa_vdev_exit(spa, NULL, txg, error));
4104 
4105         spa->spa_pending_vdev = vd;  /* spa_vdev_exit() will clear this */
4106 
4107         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
4108             &nspares) != 0)
4109                 nspares = 0;
4110 
4111         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
4112             &nl2cache) != 0)
4113                 nl2cache = 0;
4114 
4115         if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
4116                 return (spa_vdev_exit(spa, vd, txg, EINVAL));
4117 
4118         if (vd->vdev_children != 0 &&
4119             (error = vdev_create(vd, txg, B_FALSE)) != 0)
4120                 return (spa_vdev_exit(spa, vd, txg, error));
4121 
4122         /*
4123          * We must validate the spares and l2cache devices after checking the
4124          * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
4125          */
4126         if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
4127                 return (spa_vdev_exit(spa, vd, txg, error));
4128 
4129         /*
4130          * Transfer each new top-level vdev from vd to rvd.
4131          */
4132         for (int c = 0; c < vd->vdev_children; c++) {
4133 
4134                 /*
4135                  * Set the vdev id to the first hole, if one exists.
4136                  */
4137                 for (id = 0; id < rvd->vdev_children; id++) {
4138                         if (rvd->vdev_child[id]->vdev_ishole) {
4139                                 vdev_free(rvd->vdev_child[id]);
4140                                 break;
4141                         }
4142                 }
4143                 tvd = vd->vdev_child[c];
4144                 vdev_remove_child(vd, tvd);
4145                 tvd->vdev_id = id;
4146                 vdev_add_child(rvd, tvd);
4147                 vdev_config_dirty(tvd);
4148         }
4149 
4150         if (nspares != 0) {
4151                 spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
4152                     ZPOOL_CONFIG_SPARES);
4153                 spa_load_spares(spa);
4154                 spa->spa_spares.sav_sync = B_TRUE;
4155         }
4156 
4157         if (nl2cache != 0) {
4158                 spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
4159                     ZPOOL_CONFIG_L2CACHE);
4160                 spa_load_l2cache(spa);
4161                 spa->spa_l2cache.sav_sync = B_TRUE;
4162         }
4163 
4164         /*
4165          * We have to be careful when adding new vdevs to an existing pool.
4166          * If other threads start allocating from these vdevs before we
4167          * sync the config cache, and we lose power, then upon reboot we may
4168          * fail to open the pool because there are DVAs that the config cache
4169          * can't translate.  Therefore, we first add the vdevs without
4170          * initializing metaslabs; sync the config cache (via spa_vdev_exit());
4171          * and then let spa_config_update() initialize the new metaslabs.
4172          *
4173          * spa_load() checks for added-but-not-initialized vdevs, so that
4174          * if we lose power at any point in this sequence, the remaining
4175          * steps will be completed the next time we load the pool.
4176          */
4177         (void) spa_vdev_exit(spa, vd, txg, 0);
4178 
4179         mutex_enter(&spa_namespace_lock);
4180         spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4181         mutex_exit(&spa_namespace_lock);
4182 
4183         return (0);
4184 }
4185 
4186 /*
4187  * Attach a device to a mirror.  The arguments are the path to any device
4188  * in the mirror, and the nvroot for the new device.  If the path specifies
4189  * a device that is not mirrored, we automatically insert the mirror vdev.
4190  *
4191  * If 'replacing' is specified, the new device is intended to replace the
4192  * existing device; in this case the two devices are made into their own
4193  * mirror using the 'replacing' vdev, which is functionally identical to
4194  * the mirror vdev (it actually reuses all the same ops) but has a few
4195  * extra rules: you can't attach to it after it's been created, and upon
4196  * completion of resilvering, the first disk (the one being replaced)
4197  * is automatically detached.
4198  */
4199 int
4200 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
4201 {
4202         uint64_t txg, dtl_max_txg;
4203         vdev_t *rvd = spa->spa_root_vdev;
4204         vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
4205         vdev_ops_t *pvops;
4206         char *oldvdpath, *newvdpath;
4207         int newvd_isspare;
4208         int error;
4209 
4210         ASSERT(spa_writeable(spa));
4211 
4212         txg = spa_vdev_enter(spa);
4213 
4214         oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
4215 
4216         if (oldvd == NULL)
4217                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4218 
4219         if (!oldvd->vdev_ops->vdev_op_leaf)
4220                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4221 
4222         pvd = oldvd->vdev_parent;
4223 
4224         if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
4225             VDEV_ALLOC_ATTACH)) != 0)
4226                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4227 
4228         if (newrootvd->vdev_children != 1)
4229                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4230 
4231         newvd = newrootvd->vdev_child[0];
4232 
4233         if (!newvd->vdev_ops->vdev_op_leaf)
4234                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4235 
4236         if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
4237                 return (spa_vdev_exit(spa, newrootvd, txg, error));
4238 
4239         /*
4240          * Spares can't replace logs
4241          */
4242         if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
4243                 return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4244 
4245         if (!replacing) {
4246                 /*
4247                  * For attach, the only allowable parent is a mirror or the root
4248                  * vdev.
4249                  */
4250                 if (pvd->vdev_ops != &vdev_mirror_ops &&
4251                     pvd->vdev_ops != &vdev_root_ops)
4252                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4253 
4254                 pvops = &vdev_mirror_ops;
4255         } else {
4256                 /*
4257                  * Active hot spares can only be replaced by inactive hot
4258                  * spares.
4259                  */
4260                 if (pvd->vdev_ops == &vdev_spare_ops &&
4261                     oldvd->vdev_isspare &&
4262                     !spa_has_spare(spa, newvd->vdev_guid))
4263                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4264 
4265                 /*
4266                  * If the source is a hot spare, and the parent isn't already a
4267                  * spare, then we want to create a new hot spare.  Otherwise, we
4268                  * want to create a replacing vdev.  The user is not allowed to
4269                  * attach to a spared vdev child unless the 'isspare' state is
4270                  * the same (spare replaces spare, non-spare replaces
4271                  * non-spare).
4272                  */
4273                 if (pvd->vdev_ops == &vdev_replacing_ops &&
4274                     spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
4275                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4276                 } else if (pvd->vdev_ops == &vdev_spare_ops &&
4277                     newvd->vdev_isspare != oldvd->vdev_isspare) {
4278                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4279                 }
4280 
4281                 if (newvd->vdev_isspare)
4282                         pvops = &vdev_spare_ops;
4283                 else
4284                         pvops = &vdev_replacing_ops;
4285         }
4286 
4287         /*
4288          * Make sure the new device is big enough.
4289          */
4290         if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
4291                 return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
4292 
4293         /*
4294          * The new device cannot have a higher alignment requirement
4295          * than the top-level vdev.
4296          */
4297         if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
4298                 return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
4299 
4300         /*
4301          * If this is an in-place replacement, update oldvd's path and devid
4302          * to make it distinguishable from newvd, and unopenable from now on.
4303          */
4304         if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
4305                 spa_strfree(oldvd->vdev_path);
4306                 oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
4307                     KM_SLEEP);
4308                 (void) sprintf(oldvd->vdev_path, "%s/%s",
4309                     newvd->vdev_path, "old");
4310                 if (oldvd->vdev_devid != NULL) {
4311                         spa_strfree(oldvd->vdev_devid);
4312                         oldvd->vdev_devid = NULL;
4313                 }
4314         }
4315 
4316         /* mark the device being resilvered */
4317         newvd->vdev_resilvering = B_TRUE;
4318 
4319         /*
4320          * If the parent is not a mirror, or if we're replacing, insert the new
4321          * mirror/replacing/spare vdev above oldvd.
4322          */
4323         if (pvd->vdev_ops != pvops)
4324                 pvd = vdev_add_parent(oldvd, pvops);
4325 
4326         ASSERT(pvd->vdev_top->vdev_parent == rvd);
4327         ASSERT(pvd->vdev_ops == pvops);
4328         ASSERT(oldvd->vdev_parent == pvd);
4329 
4330         /*
4331          * Extract the new device from its root and add it to pvd.
4332          */
4333         vdev_remove_child(newrootvd, newvd);
4334         newvd->vdev_id = pvd->vdev_children;
4335         newvd->vdev_crtxg = oldvd->vdev_crtxg;
4336         vdev_add_child(pvd, newvd);
4337 
4338         tvd = newvd->vdev_top;
4339         ASSERT(pvd->vdev_top == tvd);
4340         ASSERT(tvd->vdev_parent == rvd);
4341 
4342         vdev_config_dirty(tvd);
4343 
4344         /*
4345          * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
4346          * for any dmu_sync-ed blocks.  It will propagate upward when
4347          * spa_vdev_exit() calls vdev_dtl_reassess().
4348          */
4349         dtl_max_txg = txg + TXG_CONCURRENT_STATES;
4350 
4351         vdev_dtl_dirty(newvd, DTL_MISSING, TXG_INITIAL,
4352             dtl_max_txg - TXG_INITIAL);
4353 
4354         if (newvd->vdev_isspare) {
4355                 spa_spare_activate(newvd);
4356                 spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
4357         }
4358 
4359         oldvdpath = spa_strdup(oldvd->vdev_path);
4360         newvdpath = spa_strdup(newvd->vdev_path);
4361         newvd_isspare = newvd->vdev_isspare;
4362 
4363         /*
4364          * Mark newvd's DTL dirty in this txg.
4365          */
4366         vdev_dirty(tvd, VDD_DTL, newvd, txg);
4367 
4368         /*
4369          * Restart the resilver
4370          */
4371         dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
4372 
4373         /*
4374          * Commit the config
4375          */
4376         (void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
4377 
4378         spa_history_log_internal(spa, "vdev attach", NULL,
4379             "%s vdev=%s %s vdev=%s",
4380             replacing && newvd_isspare ? "spare in" :
4381             replacing ? "replace" : "attach", newvdpath,
4382             replacing ? "for" : "to", oldvdpath);
4383 
4384         spa_strfree(oldvdpath);
4385         spa_strfree(newvdpath);
4386 
4387         if (spa->spa_bootfs)
4388                 spa_event_notify(spa, newvd, ESC_ZFS_BOOTFS_VDEV_ATTACH);
4389 
4390         return (0);
4391 }
4392 
4393 /*
4394  * Detach a device from a mirror or replacing vdev.
4395  * If 'replace_done' is specified, only detach if the parent
4396  * is a replacing vdev.
4397  */
4398 int
4399 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
4400 {
4401         uint64_t txg;
4402         int error;
4403         vdev_t *rvd = spa->spa_root_vdev;
4404         vdev_t *vd, *pvd, *cvd, *tvd;
4405         boolean_t unspare = B_FALSE;
4406         uint64_t unspare_guid;
4407         char *vdpath;
4408 
4409         ASSERT(spa_writeable(spa));
4410 
4411         txg = spa_vdev_enter(spa);
4412 
4413         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4414 
4415         if (vd == NULL)
4416                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4417 
4418         if (!vd->vdev_ops->vdev_op_leaf)
4419                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4420 
4421         pvd = vd->vdev_parent;
4422 
4423         /*
4424          * If the parent/child relationship is not as expected, don't do it.
4425          * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
4426          * vdev that's replacing B with C.  The user's intent in replacing
4427          * is to go from M(A,B) to M(A,C).  If the user decides to cancel
4428          * the replace by detaching C, the expected behavior is to end up
4429          * M(A,B).  But suppose that right after deciding to detach C,
4430          * the replacement of B completes.  We would have M(A,C), and then
4431          * ask to detach C, which would leave us with just A -- not what
4432          * the user wanted.  To prevent this, we make sure that the
4433          * parent/child relationship hasn't changed -- in this example,
4434          * that C's parent is still the replacing vdev R.
4435          */
4436         if (pvd->vdev_guid != pguid && pguid != 0)
4437                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4438 
4439         /*
4440          * Only 'replacing' or 'spare' vdevs can be replaced.
4441          */
4442         if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
4443             pvd->vdev_ops != &vdev_spare_ops)
4444                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4445 
4446         ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
4447             spa_version(spa) >= SPA_VERSION_SPARES);
4448 
4449         /*
4450          * Only mirror, replacing, and spare vdevs support detach.
4451          */
4452         if (pvd->vdev_ops != &vdev_replacing_ops &&
4453             pvd->vdev_ops != &vdev_mirror_ops &&
4454             pvd->vdev_ops != &vdev_spare_ops)
4455                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4456 
4457         /*
4458          * If this device has the only valid copy of some data,
4459          * we cannot safely detach it.
4460          */
4461         if (vdev_dtl_required(vd))
4462                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4463 
4464         ASSERT(pvd->vdev_children >= 2);
4465 
4466         /*
4467          * If we are detaching the second disk from a replacing vdev, then
4468          * check to see if we changed the original vdev's path to have "/old"
4469          * at the end in spa_vdev_attach().  If so, undo that change now.
4470          */
4471         if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
4472             vd->vdev_path != NULL) {
4473                 size_t len = strlen(vd->vdev_path);
4474 
4475                 for (int c = 0; c < pvd->vdev_children; c++) {
4476                         cvd = pvd->vdev_child[c];
4477 
4478                         if (cvd == vd || cvd->vdev_path == NULL)
4479                                 continue;
4480 
4481                         if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
4482                             strcmp(cvd->vdev_path + len, "/old") == 0) {
4483                                 spa_strfree(cvd->vdev_path);
4484                                 cvd->vdev_path = spa_strdup(vd->vdev_path);
4485                                 break;
4486                         }
4487                 }
4488         }
4489 
4490         /*
4491          * If we are detaching the original disk from a spare, then it implies
4492          * that the spare should become a real disk, and be removed from the
4493          * active spare list for the pool.
4494          */
4495         if (pvd->vdev_ops == &vdev_spare_ops &&
4496             vd->vdev_id == 0 &&
4497             pvd->vdev_child[pvd->vdev_children - 1]->vdev_isspare)
4498                 unspare = B_TRUE;
4499 
4500         /*
4501          * Erase the disk labels so the disk can be used for other things.
4502          * This must be done after all other error cases are handled,
4503          * but before we disembowel vd (so we can still do I/O to it).
4504          * But if we can't do it, don't treat the error as fatal --
4505          * it may be that the unwritability of the disk is the reason
4506          * it's being detached!
4507          */
4508         error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4509 
4510         /*
4511          * Remove vd from its parent and compact the parent's children.
4512          */
4513         vdev_remove_child(pvd, vd);
4514         vdev_compact_children(pvd);
4515 
4516         /*
4517          * Remember one of the remaining children so we can get tvd below.
4518          */
4519         cvd = pvd->vdev_child[pvd->vdev_children - 1];
4520 
4521         /*
4522          * If we need to remove the remaining child from the list of hot spares,
4523          * do it now, marking the vdev as no longer a spare in the process.
4524          * We must do this before vdev_remove_parent(), because that can
4525          * change the GUID if it creates a new toplevel GUID.  For a similar
4526          * reason, we must remove the spare now, in the same txg as the detach;
4527          * otherwise someone could attach a new sibling, change the GUID, and
4528          * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
4529          */
4530         if (unspare) {
4531                 ASSERT(cvd->vdev_isspare);
4532                 spa_spare_remove(cvd);
4533                 unspare_guid = cvd->vdev_guid;
4534                 (void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
4535                 cvd->vdev_unspare = B_TRUE;
4536         }
4537 
4538         /*
4539          * If the parent mirror/replacing vdev only has one child,
4540          * the parent is no longer needed.  Remove it from the tree.
4541          */
4542         if (pvd->vdev_children == 1) {
4543                 if (pvd->vdev_ops == &vdev_spare_ops)
4544                         cvd->vdev_unspare = B_FALSE;
4545                 vdev_remove_parent(cvd);
4546                 cvd->vdev_resilvering = B_FALSE;
4547         }
4548 
4549 
4550         /*
4551          * We don't set tvd until now because the parent we just removed
4552          * may have been the previous top-level vdev.
4553          */
4554         tvd = cvd->vdev_top;
4555         ASSERT(tvd->vdev_parent == rvd);
4556 
4557         /*
4558          * Reevaluate the parent vdev state.
4559          */
4560         vdev_propagate_state(cvd);
4561 
4562         /*
4563          * If the 'autoexpand' property is set on the pool then automatically
4564          * try to expand the size of the pool. For example if the device we
4565          * just detached was smaller than the others, it may be possible to
4566          * add metaslabs (i.e. grow the pool). We need to reopen the vdev
4567          * first so that we can obtain the updated sizes of the leaf vdevs.
4568          */
4569         if (spa->spa_autoexpand) {
4570                 vdev_reopen(tvd);
4571                 vdev_expand(tvd, txg);
4572         }
4573 
4574         vdev_config_dirty(tvd);
4575 
4576         /*
4577          * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
4578          * vd->vdev_detached is set and free vd's DTL object in syncing context.
4579          * But first make sure we're not on any *other* txg's DTL list, to
4580          * prevent vd from being accessed after it's freed.
4581          */
4582         vdpath = spa_strdup(vd->vdev_path);
4583         for (int t = 0; t < TXG_SIZE; t++)
4584                 (void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
4585         vd->vdev_detached = B_TRUE;
4586         vdev_dirty(tvd, VDD_DTL, vd, txg);
4587 
4588         spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
4589 
4590         /* hang on to the spa before we release the lock */
4591         spa_open_ref(spa, FTAG);
4592 
4593         error = spa_vdev_exit(spa, vd, txg, 0);
4594 
4595         spa_history_log_internal(spa, "detach", NULL,
4596             "vdev=%s", vdpath);
4597         spa_strfree(vdpath);
4598 
4599         /*
4600          * If this was the removal of the original device in a hot spare vdev,
4601          * then we want to go through and remove the device from the hot spare
4602          * list of every other pool.
4603          */
4604         if (unspare) {
4605                 spa_t *altspa = NULL;
4606 
4607                 mutex_enter(&spa_namespace_lock);
4608                 while ((altspa = spa_next(altspa)) != NULL) {
4609                         if (altspa->spa_state != POOL_STATE_ACTIVE ||
4610                             altspa == spa)
4611                                 continue;
4612 
4613                         spa_open_ref(altspa, FTAG);
4614                         mutex_exit(&spa_namespace_lock);
4615                         (void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
4616                         mutex_enter(&spa_namespace_lock);
4617                         spa_close(altspa, FTAG);
4618                 }
4619                 mutex_exit(&spa_namespace_lock);
4620 
4621                 /* search the rest of the vdevs for spares to remove */
4622                 spa_vdev_resilver_done(spa);
4623         }
4624 
4625         /* all done with the spa; OK to release */
4626         mutex_enter(&spa_namespace_lock);
4627         spa_close(spa, FTAG);
4628         mutex_exit(&spa_namespace_lock);
4629 
4630         return (error);
4631 }
4632 
4633 /*
4634  * Split a set of devices from their mirrors, and create a new pool from them.
4635  */
4636 int
4637 spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
4638     nvlist_t *props, boolean_t exp)
4639 {
4640         int error = 0;
4641         uint64_t txg, *glist;
4642         spa_t *newspa;
4643         uint_t c, children, lastlog;
4644         nvlist_t **child, *nvl, *tmp;
4645         dmu_tx_t *tx;
4646         char *altroot = NULL;
4647         vdev_t *rvd, **vml = NULL;                      /* vdev modify list */
4648         boolean_t activate_slog;
4649 
4650         ASSERT(spa_writeable(spa));
4651 
4652         txg = spa_vdev_enter(spa);
4653 
4654         /* clear the log and flush everything up to now */
4655         activate_slog = spa_passivate_log(spa);
4656         (void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4657         error = spa_offline_log(spa);
4658         txg = spa_vdev_config_enter(spa);
4659 
4660         if (activate_slog)
4661                 spa_activate_log(spa);
4662 
4663         if (error != 0)
4664                 return (spa_vdev_exit(spa, NULL, txg, error));
4665 
4666         /* check new spa name before going any further */
4667         if (spa_lookup(newname) != NULL)
4668                 return (spa_vdev_exit(spa, NULL, txg, EEXIST));
4669 
4670         /*
4671          * scan through all the children to ensure they're all mirrors
4672          */
4673         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
4674             nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
4675             &children) != 0)
4676                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4677 
4678         /* first, check to ensure we've got the right child count */
4679         rvd = spa->spa_root_vdev;
4680         lastlog = 0;
4681         for (c = 0; c < rvd->vdev_children; c++) {
4682                 vdev_t *vd = rvd->vdev_child[c];
4683 
4684                 /* don't count the holes & logs as children */
4685                 if (vd->vdev_islog || vd->vdev_ishole) {
4686                         if (lastlog == 0)
4687                                 lastlog = c;
4688                         continue;
4689                 }
4690 
4691                 lastlog = 0;
4692         }
4693         if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
4694                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4695 
4696         /* next, ensure no spare or cache devices are part of the split */
4697         if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
4698             nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
4699                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4700 
4701         vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
4702         glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
4703 
4704         /* then, loop over each vdev and validate it */
4705         for (c = 0; c < children; c++) {
4706                 uint64_t is_hole = 0;
4707 
4708                 (void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
4709                     &is_hole);
4710 
4711                 if (is_hole != 0) {
4712                         if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
4713                             spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
4714                                 continue;
4715                         } else {
4716                                 error = EINVAL;
4717                                 break;
4718                         }
4719                 }
4720 
4721                 /* which disk is going to be split? */
4722                 if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
4723                     &glist[c]) != 0) {
4724                         error = EINVAL;
4725                         break;
4726                 }
4727 
4728                 /* look it up in the spa */
4729                 vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
4730                 if (vml[c] == NULL) {
4731                         error = ENODEV;
4732                         break;
4733                 }
4734 
4735                 /* make sure there's nothing stopping the split */
4736                 if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
4737                     vml[c]->vdev_islog ||
4738                     vml[c]->vdev_ishole ||
4739                     vml[c]->vdev_isspare ||
4740                     vml[c]->vdev_isl2cache ||
4741                     !vdev_writeable(vml[c]) ||
4742                     vml[c]->vdev_children != 0 ||
4743                     vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
4744                     c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
4745                         error = EINVAL;
4746                         break;
4747                 }
4748 
4749                 if (vdev_dtl_required(vml[c])) {
4750                         error = EBUSY;
4751                         break;
4752                 }
4753 
4754                 /* we need certain info from the top level */
4755                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
4756                     vml[c]->vdev_top->vdev_ms_array) == 0);
4757                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
4758                     vml[c]->vdev_top->vdev_ms_shift) == 0);
4759                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
4760                     vml[c]->vdev_top->vdev_asize) == 0);
4761                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
4762                     vml[c]->vdev_top->vdev_ashift) == 0);
4763         }
4764 
4765         if (error != 0) {
4766                 kmem_free(vml, children * sizeof (vdev_t *));
4767                 kmem_free(glist, children * sizeof (uint64_t));
4768                 return (spa_vdev_exit(spa, NULL, txg, error));
4769         }
4770 
4771         /* stop writers from using the disks */
4772         for (c = 0; c < children; c++) {
4773                 if (vml[c] != NULL)
4774                         vml[c]->vdev_offline = B_TRUE;
4775         }
4776         vdev_reopen(spa->spa_root_vdev);
4777 
4778         /*
4779          * Temporarily record the splitting vdevs in the spa config.  This
4780          * will disappear once the config is regenerated.
4781          */
4782         VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0);
4783         VERIFY(nvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
4784             glist, children) == 0);
4785         kmem_free(glist, children * sizeof (uint64_t));
4786 
4787         mutex_enter(&spa->spa_props_lock);
4788         VERIFY(nvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT,
4789             nvl) == 0);
4790         mutex_exit(&spa->spa_props_lock);
4791         spa->spa_config_splitting = nvl;
4792         vdev_config_dirty(spa->spa_root_vdev);
4793 
4794         /* configure and create the new pool */
4795         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname) == 0);
4796         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4797             exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE) == 0);
4798         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
4799             spa_version(spa)) == 0);
4800         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
4801             spa->spa_config_txg) == 0);
4802         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
4803             spa_generate_guid(NULL)) == 0);
4804         (void) nvlist_lookup_string(props,
4805             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
4806 
4807         /* add the new pool to the namespace */
4808         newspa = spa_add(newname, config, altroot);
4809         newspa->spa_config_txg = spa->spa_config_txg;
4810         spa_set_log_state(newspa, SPA_LOG_CLEAR);
4811 
4812         /* release the spa config lock, retaining the namespace lock */
4813         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4814 
4815         if (zio_injection_enabled)
4816                 zio_handle_panic_injection(spa, FTAG, 1);
4817 
4818         spa_activate(newspa, spa_mode_global);
4819         spa_async_suspend(newspa);
4820 
4821         /* create the new pool from the disks of the original pool */
4822         error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE, B_TRUE);
4823         if (error)
4824                 goto out;
4825 
4826         /* if that worked, generate a real config for the new pool */
4827         if (newspa->spa_root_vdev != NULL) {
4828                 VERIFY(nvlist_alloc(&newspa->spa_config_splitting,
4829                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
4830                 VERIFY(nvlist_add_uint64(newspa->spa_config_splitting,
4831                     ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa)) == 0);
4832                 spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
4833                     B_TRUE));
4834         }
4835 
4836         /* set the props */
4837         if (props != NULL) {
4838                 spa_configfile_set(newspa, props, B_FALSE);
4839                 error = spa_prop_set(newspa, props);
4840                 if (error)
4841                         goto out;
4842         }
4843 
4844         /* flush everything */
4845         txg = spa_vdev_config_enter(newspa);
4846         vdev_config_dirty(newspa->spa_root_vdev);
4847         (void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
4848 
4849         if (zio_injection_enabled)
4850                 zio_handle_panic_injection(spa, FTAG, 2);
4851 
4852         spa_async_resume(newspa);
4853 
4854         /* finally, update the original pool's config */
4855         txg = spa_vdev_config_enter(spa);
4856         tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
4857         error = dmu_tx_assign(tx, TXG_WAIT);
4858         if (error != 0)
4859                 dmu_tx_abort(tx);
4860         for (c = 0; c < children; c++) {
4861                 if (vml[c] != NULL) {
4862                         vdev_split(vml[c]);
4863                         if (error == 0)
4864                                 spa_history_log_internal(spa, "detach", tx,
4865                                     "vdev=%s", vml[c]->vdev_path);
4866                         vdev_free(vml[c]);
4867                 }
4868         }
4869         vdev_config_dirty(spa->spa_root_vdev);
4870         spa->spa_config_splitting = NULL;
4871         nvlist_free(nvl);
4872         if (error == 0)
4873                 dmu_tx_commit(tx);
4874         (void) spa_vdev_exit(spa, NULL, txg, 0);
4875 
4876         if (zio_injection_enabled)
4877                 zio_handle_panic_injection(spa, FTAG, 3);
4878 
4879         /* split is complete; log a history record */
4880         spa_history_log_internal(newspa, "split", NULL,
4881             "from pool %s", spa_name(spa));
4882 
4883         kmem_free(vml, children * sizeof (vdev_t *));
4884 
4885         /* if we're not going to mount the filesystems in userland, export */
4886         if (exp)
4887                 error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
4888                     B_FALSE, B_FALSE);
4889 
4890         return (error);
4891 
4892 out:
4893         spa_unload(newspa);
4894         spa_deactivate(newspa);
4895         spa_remove(newspa);
4896 
4897         txg = spa_vdev_config_enter(spa);
4898 
4899         /* re-online all offlined disks */
4900         for (c = 0; c < children; c++) {
4901                 if (vml[c] != NULL)
4902                         vml[c]->vdev_offline = B_FALSE;
4903         }
4904         vdev_reopen(spa->spa_root_vdev);
4905 
4906         nvlist_free(spa->spa_config_splitting);
4907         spa->spa_config_splitting = NULL;
4908         (void) spa_vdev_exit(spa, NULL, txg, error);
4909 
4910         kmem_free(vml, children * sizeof (vdev_t *));
4911         return (error);
4912 }
4913 
4914 static nvlist_t *
4915 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
4916 {
4917         for (int i = 0; i < count; i++) {
4918                 uint64_t guid;
4919 
4920                 VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
4921                     &guid) == 0);
4922 
4923                 if (guid == target_guid)
4924                         return (nvpp[i]);
4925         }
4926 
4927         return (NULL);
4928 }
4929 
4930 static void
4931 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
4932         nvlist_t *dev_to_remove)
4933 {
4934         nvlist_t **newdev = NULL;
4935 
4936         if (count > 1)
4937                 newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
4938 
4939         for (int i = 0, j = 0; i < count; i++) {
4940                 if (dev[i] == dev_to_remove)
4941                         continue;
4942                 VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
4943         }
4944 
4945         VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
4946         VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
4947 
4948         for (int i = 0; i < count - 1; i++)
4949                 nvlist_free(newdev[i]);
4950 
4951         if (count > 1)
4952                 kmem_free(newdev, (count - 1) * sizeof (void *));
4953 }
4954 
4955 /*
4956  * Evacuate the device.
4957  */
4958 static int
4959 spa_vdev_remove_evacuate(spa_t *spa, vdev_t *vd)
4960 {
4961         uint64_t txg;
4962         int error = 0;
4963 
4964         ASSERT(MUTEX_HELD(&spa_namespace_lock));
4965         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
4966         ASSERT(vd == vd->vdev_top);
4967 
4968         /*
4969          * Evacuate the device.  We don't hold the config lock as writer
4970          * since we need to do I/O but we do keep the
4971          * spa_namespace_lock held.  Once this completes the device
4972          * should no longer have any blocks allocated on it.
4973          */
4974         if (vd->vdev_islog) {
4975                 if (vd->vdev_stat.vs_alloc != 0)
4976                         error = spa_offline_log(spa);
4977         } else {
4978                 error = ENOTSUP;
4979         }
4980 
4981         if (error)
4982                 return (error);
4983 
4984         /*
4985          * The evacuation succeeded.  Remove any remaining MOS metadata
4986          * associated with this vdev, and wait for these changes to sync.
4987          */
4988         ASSERT3U(vd->vdev_stat.vs_alloc, ==, 0);
4989         txg = spa_vdev_config_enter(spa);
4990         vd->vdev_removing = B_TRUE;
4991         vdev_dirty(vd, 0, NULL, txg);
4992         vdev_config_dirty(vd);
4993         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4994 
4995         return (0);
4996 }
4997 
4998 /*
4999  * Complete the removal by cleaning up the namespace.
5000  */
5001 static void
5002 spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
5003 {
5004         vdev_t *rvd = spa->spa_root_vdev;
5005         uint64_t id = vd->vdev_id;
5006         boolean_t last_vdev = (id == (rvd->vdev_children - 1));
5007 
5008         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5009         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
5010         ASSERT(vd == vd->vdev_top);
5011 
5012         /*
5013          * Only remove any devices which are empty.
5014          */
5015         if (vd->vdev_stat.vs_alloc != 0)
5016                 return;
5017 
5018         (void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
5019 
5020         if (list_link_active(&vd->vdev_state_dirty_node))
5021                 vdev_state_clean(vd);
5022         if (list_link_active(&vd->vdev_config_dirty_node))
5023                 vdev_config_clean(vd);
5024 
5025         vdev_free(vd);
5026 
5027         if (last_vdev) {
5028                 vdev_compact_children(rvd);
5029         } else {
5030                 vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops);
5031                 vdev_add_child(rvd, vd);
5032         }
5033         vdev_config_dirty(rvd);
5034 
5035         /*
5036          * Reassess the health of our root vdev.
5037          */
5038         vdev_reopen(rvd);
5039 }
5040 
5041 /*
5042  * Remove a device from the pool -
5043  *
5044  * Removing a device from the vdev namespace requires several steps
5045  * and can take a significant amount of time.  As a result we use
5046  * the spa_vdev_config_[enter/exit] functions which allow us to
5047  * grab and release the spa_config_lock while still holding the namespace
5048  * lock.  During each step the configuration is synced out.
5049  */
5050 
5051 /*
5052  * Remove a device from the pool.  Currently, this supports removing only hot
5053  * spares, slogs, and level 2 ARC devices.
5054  */
5055 int
5056 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
5057 {
5058         vdev_t *vd;
5059         metaslab_group_t *mg;
5060         nvlist_t **spares, **l2cache, *nv;
5061         uint64_t txg = 0;
5062         uint_t nspares, nl2cache;
5063         int error = 0;
5064         boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
5065 
5066         ASSERT(spa_writeable(spa));
5067 
5068         if (!locked)
5069                 txg = spa_vdev_enter(spa);
5070 
5071         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
5072 
5073         if (spa->spa_spares.sav_vdevs != NULL &&
5074             nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
5075             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
5076             (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
5077                 /*
5078                  * Only remove the hot spare if it's not currently in use
5079                  * in this pool.
5080                  */
5081                 if (vd == NULL || unspare) {
5082                         spa_vdev_remove_aux(spa->spa_spares.sav_config,
5083                             ZPOOL_CONFIG_SPARES, spares, nspares, nv);
5084                         spa_load_spares(spa);
5085                         spa->spa_spares.sav_sync = B_TRUE;
5086                 } else {
5087                         error = EBUSY;
5088                 }
5089         } else if (spa->spa_l2cache.sav_vdevs != NULL &&
5090             nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
5091             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
5092             (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
5093                 /*
5094                  * Cache devices can always be removed.
5095                  */
5096                 spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
5097                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
5098                 spa_load_l2cache(spa);
5099                 spa->spa_l2cache.sav_sync = B_TRUE;
5100         } else if (vd != NULL && vd->vdev_islog) {
5101                 ASSERT(!locked);
5102                 ASSERT(vd == vd->vdev_top);
5103 
5104                 /*
5105                  * XXX - Once we have bp-rewrite this should
5106                  * become the common case.
5107                  */
5108 
5109                 mg = vd->vdev_mg;
5110 
5111                 /*
5112                  * Stop allocating from this vdev.
5113                  */
5114                 metaslab_group_passivate(mg);
5115 
5116                 /*
5117                  * Wait for the youngest allocations and frees to sync,
5118                  * and then wait for the deferral of those frees to finish.
5119                  */
5120                 spa_vdev_config_exit(spa, NULL,
5121                     txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
5122 
5123                 /*
5124                  * Attempt to evacuate the vdev.
5125                  */
5126                 error = spa_vdev_remove_evacuate(spa, vd);
5127 
5128                 txg = spa_vdev_config_enter(spa);
5129 
5130                 /*
5131                  * If we couldn't evacuate the vdev, unwind.
5132                  */
5133                 if (error) {
5134                         metaslab_group_activate(mg);
5135                         return (spa_vdev_exit(spa, NULL, txg, error));
5136                 }
5137 
5138                 /*
5139                  * Clean up the vdev namespace.
5140                  */
5141                 spa_vdev_remove_from_namespace(spa, vd);
5142 
5143         } else if (vd != NULL) {
5144                 /*
5145                  * Normal vdevs cannot be removed (yet).
5146                  */
5147                 error = ENOTSUP;
5148         } else {
5149                 /*
5150                  * There is no vdev of any kind with the specified guid.
5151                  */
5152                 error = ENOENT;
5153         }
5154 
5155         if (!locked)
5156                 return (spa_vdev_exit(spa, NULL, txg, error));
5157 
5158         return (error);
5159 }
5160 
5161 /*
5162  * Find any device that's done replacing, or a vdev marked 'unspare' that's
5163  * current spared, so we can detach it.
5164  */
5165 static vdev_t *
5166 spa_vdev_resilver_done_hunt(vdev_t *vd)
5167 {
5168         vdev_t *newvd, *oldvd;
5169 
5170         for (int c = 0; c < vd->vdev_children; c++) {
5171                 oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
5172                 if (oldvd != NULL)
5173                         return (oldvd);
5174         }
5175 
5176         /*
5177          * Check for a completed replacement.  We always consider the first
5178          * vdev in the list to be the oldest vdev, and the last one to be
5179          * the newest (see spa_vdev_attach() for how that works).  In
5180          * the case where the newest vdev is faulted, we will not automatically
5181          * remove it after a resilver completes.  This is OK as it will require
5182          * user intervention to determine which disk the admin wishes to keep.
5183          */
5184         if (vd->vdev_ops == &vdev_replacing_ops) {
5185                 ASSERT(vd->vdev_children > 1);
5186 
5187                 newvd = vd->vdev_child[vd->vdev_children - 1];
5188                 oldvd = vd->vdev_child[0];
5189 
5190                 if (vdev_dtl_empty(newvd, DTL_MISSING) &&
5191                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5192                     !vdev_dtl_required(oldvd))
5193                         return (oldvd);
5194         }
5195 
5196         /*
5197          * Check for a completed resilver with the 'unspare' flag set.
5198          */
5199         if (vd->vdev_ops == &vdev_spare_ops) {
5200                 vdev_t *first = vd->vdev_child[0];
5201                 vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
5202 
5203                 if (last->vdev_unspare) {
5204                         oldvd = first;
5205                         newvd = last;
5206                 } else if (first->vdev_unspare) {
5207                         oldvd = last;
5208                         newvd = first;
5209                 } else {
5210                         oldvd = NULL;
5211                 }
5212 
5213                 if (oldvd != NULL &&
5214                     vdev_dtl_empty(newvd, DTL_MISSING) &&
5215                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5216                     !vdev_dtl_required(oldvd))
5217                         return (oldvd);
5218 
5219                 /*
5220                  * If there are more than two spares attached to a disk,
5221                  * and those spares are not required, then we want to
5222                  * attempt to free them up now so that they can be used
5223                  * by other pools.  Once we're back down to a single
5224                  * disk+spare, we stop removing them.
5225                  */
5226                 if (vd->vdev_children > 2) {
5227                         newvd = vd->vdev_child[1];
5228 
5229                         if (newvd->vdev_isspare && last->vdev_isspare &&
5230                             vdev_dtl_empty(last, DTL_MISSING) &&
5231                             vdev_dtl_empty(last, DTL_OUTAGE) &&
5232                             !vdev_dtl_required(newvd))
5233                                 return (newvd);
5234                 }
5235         }
5236 
5237         return (NULL);
5238 }
5239 
5240 static void
5241 spa_vdev_resilver_done(spa_t *spa)
5242 {
5243         vdev_t *vd, *pvd, *ppvd;
5244         uint64_t guid, sguid, pguid, ppguid;
5245 
5246         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5247 
5248         while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
5249                 pvd = vd->vdev_parent;
5250                 ppvd = pvd->vdev_parent;
5251                 guid = vd->vdev_guid;
5252                 pguid = pvd->vdev_guid;
5253                 ppguid = ppvd->vdev_guid;
5254                 sguid = 0;
5255                 /*
5256                  * If we have just finished replacing a hot spared device, then
5257                  * we need to detach the parent's first child (the original hot
5258                  * spare) as well.
5259                  */
5260                 if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
5261                     ppvd->vdev_children == 2) {
5262                         ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
5263                         sguid = ppvd->vdev_child[1]->vdev_guid;
5264                 }
5265                 spa_config_exit(spa, SCL_ALL, FTAG);
5266                 if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
5267                         return;
5268                 if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
5269                         return;
5270                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5271         }
5272 
5273         spa_config_exit(spa, SCL_ALL, FTAG);
5274 }
5275 
5276 /*
5277  * Update the stored path or FRU for this vdev.
5278  */
5279 int
5280 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
5281     boolean_t ispath)
5282 {
5283         vdev_t *vd;
5284         boolean_t sync = B_FALSE;
5285 
5286         ASSERT(spa_writeable(spa));
5287 
5288         spa_vdev_state_enter(spa, SCL_ALL);
5289 
5290         if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
5291                 return (spa_vdev_state_exit(spa, NULL, ENOENT));
5292 
5293         if (!vd->vdev_ops->vdev_op_leaf)
5294                 return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
5295 
5296         if (ispath) {
5297                 if (strcmp(value, vd->vdev_path) != 0) {
5298                         spa_strfree(vd->vdev_path);
5299                         vd->vdev_path = spa_strdup(value);
5300                         sync = B_TRUE;
5301                 }
5302         } else {
5303                 if (vd->vdev_fru == NULL) {
5304                         vd->vdev_fru = spa_strdup(value);
5305                         sync = B_TRUE;
5306                 } else if (strcmp(value, vd->vdev_fru) != 0) {
5307                         spa_strfree(vd->vdev_fru);
5308                         vd->vdev_fru = spa_strdup(value);
5309                         sync = B_TRUE;
5310                 }
5311         }
5312 
5313         return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
5314 }
5315 
5316 int
5317 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
5318 {
5319         return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
5320 }
5321 
5322 int
5323 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
5324 {
5325         return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
5326 }
5327 
5328 /*
5329  * ==========================================================================
5330  * SPA Scanning
5331  * ==========================================================================
5332  */
5333 
5334 int
5335 spa_scan_stop(spa_t *spa)
5336 {
5337         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5338         if (dsl_scan_resilvering(spa->spa_dsl_pool))
5339                 return (EBUSY);
5340         return (dsl_scan_cancel(spa->spa_dsl_pool));
5341 }
5342 
5343 int
5344 spa_scan(spa_t *spa, pool_scan_func_t func)
5345 {
5346         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5347 
5348         if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
5349                 return (ENOTSUP);
5350 
5351         /*
5352          * If a resilver was requested, but there is no DTL on a
5353          * writeable leaf device, we have nothing to do.
5354          */
5355         if (func == POOL_SCAN_RESILVER &&
5356             !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
5357                 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
5358                 return (0);
5359         }
5360 
5361         return (dsl_scan(spa->spa_dsl_pool, func));
5362 }
5363 
5364 /*
5365  * ==========================================================================
5366  * SPA async task processing
5367  * ==========================================================================
5368  */
5369 
5370 static void
5371 spa_async_remove(spa_t *spa, vdev_t *vd)
5372 {
5373         if (vd->vdev_remove_wanted) {
5374                 vd->vdev_remove_wanted = B_FALSE;
5375                 vd->vdev_delayed_close = B_FALSE;
5376                 vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
5377 
5378                 /*
5379                  * We want to clear the stats, but we don't want to do a full
5380                  * vdev_clear() as that will cause us to throw away
5381                  * degraded/faulted state as well as attempt to reopen the
5382                  * device, all of which is a waste.
5383                  */
5384                 vd->vdev_stat.vs_read_errors = 0;
5385                 vd->vdev_stat.vs_write_errors = 0;
5386                 vd->vdev_stat.vs_checksum_errors = 0;
5387 
5388                 vdev_state_dirty(vd->vdev_top);
5389         }
5390 
5391         for (int c = 0; c < vd->vdev_children; c++)
5392                 spa_async_remove(spa, vd->vdev_child[c]);
5393 }
5394 
5395 static void
5396 spa_async_probe(spa_t *spa, vdev_t *vd)
5397 {
5398         if (vd->vdev_probe_wanted) {
5399                 vd->vdev_probe_wanted = B_FALSE;
5400                 vdev_reopen(vd);        /* vdev_open() does the actual probe */
5401         }
5402 
5403         for (int c = 0; c < vd->vdev_children; c++)
5404                 spa_async_probe(spa, vd->vdev_child[c]);
5405 }
5406 
5407 static void
5408 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
5409 {
5410         sysevent_id_t eid;
5411         nvlist_t *attr;
5412         char *physpath;
5413 
5414         if (!spa->spa_autoexpand)
5415                 return;
5416 
5417         for (int c = 0; c < vd->vdev_children; c++) {
5418                 vdev_t *cvd = vd->vdev_child[c];
5419                 spa_async_autoexpand(spa, cvd);
5420         }
5421 
5422         if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
5423                 return;
5424 
5425         physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
5426         (void) snprintf(physpath, MAXPATHLEN, "/devices%s", vd->vdev_physpath);
5427 
5428         VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5429         VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
5430 
5431         (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
5432             ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
5433 
5434         nvlist_free(attr);
5435         kmem_free(physpath, MAXPATHLEN);
5436 }
5437 
5438 static void
5439 spa_async_thread(spa_t *spa)
5440 {
5441         int tasks;
5442 
5443         ASSERT(spa->spa_sync_on);
5444 
5445         mutex_enter(&spa->spa_async_lock);
5446         tasks = spa->spa_async_tasks;
5447         spa->spa_async_tasks = 0;
5448         mutex_exit(&spa->spa_async_lock);
5449 
5450         /*
5451          * See if the config needs to be updated.
5452          */
5453         if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
5454                 uint64_t old_space, new_space;
5455 
5456                 mutex_enter(&spa_namespace_lock);
5457                 old_space = metaslab_class_get_space(spa_normal_class(spa));
5458                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
5459                 new_space = metaslab_class_get_space(spa_normal_class(spa));
5460                 mutex_exit(&spa_namespace_lock);
5461 
5462                 /*
5463                  * If the pool grew as a result of the config update,
5464                  * then log an internal history event.
5465                  */
5466                 if (new_space != old_space) {
5467                         spa_history_log_internal(spa, "vdev online", NULL,
5468                             "pool '%s' size: %llu(+%llu)",
5469                             spa_name(spa), new_space, new_space - old_space);
5470                 }
5471         }
5472 
5473         /*
5474          * See if any devices need to be marked REMOVED.
5475          */
5476         if (tasks & SPA_ASYNC_REMOVE) {
5477                 spa_vdev_state_enter(spa, SCL_NONE);
5478                 spa_async_remove(spa, spa->spa_root_vdev);
5479                 for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
5480                         spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
5481                 for (int i = 0; i < spa->spa_spares.sav_count; i++)
5482                         spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
5483                 (void) spa_vdev_state_exit(spa, NULL, 0);
5484         }
5485 
5486         if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
5487                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5488                 spa_async_autoexpand(spa, spa->spa_root_vdev);
5489                 spa_config_exit(spa, SCL_CONFIG, FTAG);
5490         }
5491 
5492         /*
5493          * See if any devices need to be probed.
5494          */
5495         if (tasks & SPA_ASYNC_PROBE) {
5496                 spa_vdev_state_enter(spa, SCL_NONE);
5497                 spa_async_probe(spa, spa->spa_root_vdev);
5498                 (void) spa_vdev_state_exit(spa, NULL, 0);
5499         }
5500 
5501         /*
5502          * If any devices are done replacing, detach them.
5503          */
5504         if (tasks & SPA_ASYNC_RESILVER_DONE)
5505                 spa_vdev_resilver_done(spa);
5506 
5507         /*
5508          * Kick off a resilver.
5509          */
5510         if (tasks & SPA_ASYNC_RESILVER)
5511                 dsl_resilver_restart(spa->spa_dsl_pool, 0);
5512 
5513         /*
5514          * Let the world know that we're done.
5515          */
5516         mutex_enter(&spa->spa_async_lock);
5517         spa->spa_async_thread = NULL;
5518         cv_broadcast(&spa->spa_async_cv);
5519         mutex_exit(&spa->spa_async_lock);
5520         thread_exit();
5521 }
5522 
5523 void
5524 spa_async_suspend(spa_t *spa)
5525 {
5526         mutex_enter(&spa->spa_async_lock);
5527         spa->spa_async_suspended++;
5528         while (spa->spa_async_thread != NULL)
5529                 cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
5530         mutex_exit(&spa->spa_async_lock);
5531 }
5532 
5533 void
5534 spa_async_resume(spa_t *spa)
5535 {
5536         mutex_enter(&spa->spa_async_lock);
5537         ASSERT(spa->spa_async_suspended != 0);
5538         spa->spa_async_suspended--;
5539         mutex_exit(&spa->spa_async_lock);
5540 }
5541 
5542 static void
5543 spa_async_dispatch(spa_t *spa)
5544 {
5545         mutex_enter(&spa->spa_async_lock);
5546         if (spa->spa_async_tasks && !spa->spa_async_suspended &&
5547             spa->spa_async_thread == NULL &&
5548             rootdir != NULL && !vn_is_readonly(rootdir))
5549                 spa->spa_async_thread = thread_create(NULL, 0,
5550                     spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
5551         mutex_exit(&spa->spa_async_lock);
5552 }
5553 
5554 void
5555 spa_async_request(spa_t *spa, int task)
5556 {
5557         zfs_dbgmsg("spa=%s async request task=%u", spa->spa_name, task);
5558         mutex_enter(&spa->spa_async_lock);
5559         spa->spa_async_tasks |= task;
5560         mutex_exit(&spa->spa_async_lock);
5561 }
5562 
5563 /*
5564  * ==========================================================================
5565  * SPA syncing routines
5566  * ==========================================================================
5567  */
5568 
5569 static int
5570 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5571 {
5572         bpobj_t *bpo = arg;
5573         bpobj_enqueue(bpo, bp, tx);
5574         return (0);
5575 }
5576 
5577 static int
5578 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5579 {
5580         zio_t *zio = arg;
5581 
5582         zio_nowait(zio_free_sync(zio, zio->io_spa, dmu_tx_get_txg(tx), bp,
5583             zio->io_flags));
5584         return (0);
5585 }
5586 
5587 static void
5588 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
5589 {
5590         char *packed = NULL;
5591         size_t bufsize;
5592         size_t nvsize = 0;
5593         dmu_buf_t *db;
5594 
5595         VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
5596 
5597         /*
5598          * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
5599          * information.  This avoids the dbuf_will_dirty() path and
5600          * saves us a pre-read to get data we don't actually care about.
5601          */
5602         bufsize = P2ROUNDUP((uint64_t)nvsize, SPA_CONFIG_BLOCKSIZE);
5603         packed = kmem_alloc(bufsize, KM_SLEEP);
5604 
5605         VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
5606             KM_SLEEP) == 0);
5607         bzero(packed + nvsize, bufsize - nvsize);
5608 
5609         dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
5610 
5611         kmem_free(packed, bufsize);
5612 
5613         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
5614         dmu_buf_will_dirty(db, tx);
5615         *(uint64_t *)db->db_data = nvsize;
5616         dmu_buf_rele(db, FTAG);
5617 }
5618 
5619 static void
5620 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
5621     const char *config, const char *entry)
5622 {
5623         nvlist_t *nvroot;
5624         nvlist_t **list;
5625         int i;
5626 
5627         if (!sav->sav_sync)
5628                 return;
5629 
5630         /*
5631          * Update the MOS nvlist describing the list of available devices.
5632          * spa_validate_aux() will have already made sure this nvlist is
5633          * valid and the vdevs are labeled appropriately.
5634          */
5635         if (sav->sav_object == 0) {
5636                 sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
5637                     DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
5638                     sizeof (uint64_t), tx);
5639                 VERIFY(zap_update(spa->spa_meta_objset,
5640                     DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
5641                     &sav->sav_object, tx) == 0);
5642         }
5643 
5644         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5645         if (sav->sav_count == 0) {
5646                 VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
5647         } else {
5648                 list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
5649                 for (i = 0; i < sav->sav_count; i++)
5650                         list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
5651                             B_FALSE, VDEV_CONFIG_L2CACHE);
5652                 VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
5653                     sav->sav_count) == 0);
5654                 for (i = 0; i < sav->sav_count; i++)
5655                         nvlist_free(list[i]);
5656                 kmem_free(list, sav->sav_count * sizeof (void *));
5657         }
5658 
5659         spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
5660         nvlist_free(nvroot);
5661 
5662         sav->sav_sync = B_FALSE;
5663 }
5664 
5665 static void
5666 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
5667 {
5668         nvlist_t *config;
5669 
5670         if (list_is_empty(&spa->spa_config_dirty_list))
5671                 return;
5672 
5673         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5674 
5675         config = spa_config_generate(spa, spa->spa_root_vdev,
5676             dmu_tx_get_txg(tx), B_FALSE);
5677 
5678         spa_config_exit(spa, SCL_STATE, FTAG);
5679 
5680         if (spa->spa_config_syncing)
5681                 nvlist_free(spa->spa_config_syncing);
5682         spa->spa_config_syncing = config;
5683 
5684         spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
5685 }
5686 
5687 static void
5688 spa_sync_version(void *arg1, void *arg2, dmu_tx_t *tx)
5689 {
5690         spa_t *spa = arg1;
5691         uint64_t version = *(uint64_t *)arg2;
5692 
5693         /*
5694          * Setting the version is special cased when first creating the pool.
5695          */
5696         ASSERT(tx->tx_txg != TXG_INITIAL);
5697 
5698         ASSERT(version <= SPA_VERSION);
5699         ASSERT(version >= spa_version(spa));
5700 
5701         spa->spa_uberblock.ub_version = version;
5702         vdev_config_dirty(spa->spa_root_vdev);
5703         spa_history_log_internal(spa, "set", tx, "version=%lld", version);
5704 }
5705 
5706 /*
5707  * Set zpool properties.
5708  */
5709 static void
5710 spa_sync_props(void *arg1, void *arg2, dmu_tx_t *tx)
5711 {
5712         spa_t *spa = arg1;
5713         objset_t *mos = spa->spa_meta_objset;
5714         nvlist_t *nvp = arg2;
5715         nvpair_t *elem = NULL;
5716 
5717         mutex_enter(&spa->spa_props_lock);
5718 
5719         while ((elem = nvlist_next_nvpair(nvp, elem))) {
5720                 uint64_t intval;
5721                 char *strval, *fname;
5722                 zpool_prop_t prop;
5723                 const char *propname;
5724                 zprop_type_t proptype;
5725                 zfeature_info_t *feature;
5726 
5727                 switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
5728                 case ZPROP_INVAL:
5729                         /*
5730                          * We checked this earlier in spa_prop_validate().
5731                          */
5732                         ASSERT(zpool_prop_feature(nvpair_name(elem)));
5733 
5734                         fname = strchr(nvpair_name(elem), '@') + 1;
5735                         VERIFY3U(0, ==, zfeature_lookup_name(fname, &feature));
5736 
5737                         spa_feature_enable(spa, feature, tx);
5738                         spa_history_log_internal(spa, "set", tx,
5739                             "%s=enabled", nvpair_name(elem));
5740                         break;
5741 
5742                 case ZPOOL_PROP_VERSION:
5743                         VERIFY(nvpair_value_uint64(elem, &intval) == 0);
5744                         /*
5745                          * The version is synced seperatly before other
5746                          * properties and should be correct by now.
5747                          */
5748                         ASSERT3U(spa_version(spa), >=, intval);
5749                         break;
5750 
5751                 case ZPOOL_PROP_ALTROOT:
5752                         /*
5753                          * 'altroot' is a non-persistent property. It should
5754                          * have been set temporarily at creation or import time.
5755                          */
5756                         ASSERT(spa->spa_root != NULL);
5757                         break;
5758 
5759                 case ZPOOL_PROP_READONLY:
5760                 case ZPOOL_PROP_CACHEFILE:
5761                         /*
5762                          * 'readonly' and 'cachefile' are also non-persisitent
5763                          * properties.
5764                          */
5765                         break;
5766                 case ZPOOL_PROP_COMMENT:
5767                         VERIFY(nvpair_value_string(elem, &strval) == 0);
5768                         if (spa->spa_comment != NULL)
5769                                 spa_strfree(spa->spa_comment);
5770                         spa->spa_comment = spa_strdup(strval);
5771                         /*
5772                          * We need to dirty the configuration on all the vdevs
5773                          * so that their labels get updated.  It's unnecessary
5774                          * to do this for pool creation since the vdev's
5775                          * configuratoin has already been dirtied.
5776                          */
5777                         if (tx->tx_txg != TXG_INITIAL)
5778                                 vdev_config_dirty(spa->spa_root_vdev);
5779                         spa_history_log_internal(spa, "set", tx,
5780                             "%s=%s", nvpair_name(elem), strval);
5781                         break;
5782                 default:
5783                         /*
5784                          * Set pool property values in the poolprops mos object.
5785                          */
5786                         if (spa->spa_pool_props_object == 0) {
5787                                 spa->spa_pool_props_object =
5788                                     zap_create_link(mos, DMU_OT_POOL_PROPS,
5789                                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
5790                                     tx);
5791                         }
5792 
5793                         /* normalize the property name */
5794                         propname = zpool_prop_to_name(prop);
5795                         proptype = zpool_prop_get_type(prop);
5796 
5797                         if (nvpair_type(elem) == DATA_TYPE_STRING) {
5798                                 ASSERT(proptype == PROP_TYPE_STRING);
5799                                 VERIFY(nvpair_value_string(elem, &strval) == 0);
5800                                 VERIFY(zap_update(mos,
5801                                     spa->spa_pool_props_object, propname,
5802                                     1, strlen(strval) + 1, strval, tx) == 0);
5803                                 spa_history_log_internal(spa, "set", tx,
5804                                     "%s=%s", nvpair_name(elem), strval);
5805                         } else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
5806                                 VERIFY(nvpair_value_uint64(elem, &intval) == 0);
5807 
5808                                 if (proptype == PROP_TYPE_INDEX) {
5809                                         const char *unused;
5810                                         VERIFY(zpool_prop_index_to_string(
5811                                             prop, intval, &unused) == 0);
5812                                 }
5813                                 VERIFY(zap_update(mos,
5814                                     spa->spa_pool_props_object, propname,
5815                                     8, 1, &intval, tx) == 0);
5816                                 spa_history_log_internal(spa, "set", tx,
5817                                     "%s=%lld", nvpair_name(elem), intval);
5818                         } else {
5819                                 ASSERT(0); /* not allowed */
5820                         }
5821 
5822                         switch (prop) {
5823                         case ZPOOL_PROP_DELEGATION:
5824                                 spa->spa_delegation = intval;
5825                                 break;
5826                         case ZPOOL_PROP_BOOTFS:
5827                                 spa->spa_bootfs = intval;
5828                                 break;
5829                         case ZPOOL_PROP_FAILUREMODE:
5830                                 spa->spa_failmode = intval;
5831                                 break;
5832                         case ZPOOL_PROP_AUTOEXPAND:
5833                                 spa->spa_autoexpand = intval;
5834                                 if (tx->tx_txg != TXG_INITIAL)
5835                                         spa_async_request(spa,
5836                                             SPA_ASYNC_AUTOEXPAND);
5837                                 break;
5838                         case ZPOOL_PROP_DEDUPDITTO:
5839                                 spa->spa_dedup_ditto = intval;
5840                                 break;
5841                         default:
5842                                 break;
5843                         }
5844                 }
5845 
5846         }
5847 
5848         mutex_exit(&spa->spa_props_lock);
5849 }
5850 
5851 /*
5852  * Perform one-time upgrade on-disk changes.  spa_version() does not
5853  * reflect the new version this txg, so there must be no changes this
5854  * txg to anything that the upgrade code depends on after it executes.
5855  * Therefore this must be called after dsl_pool_sync() does the sync
5856  * tasks.
5857  */
5858 static void
5859 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
5860 {
5861         dsl_pool_t *dp = spa->spa_dsl_pool;
5862 
5863         ASSERT(spa->spa_sync_pass == 1);
5864 
5865         if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
5866             spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
5867                 dsl_pool_create_origin(dp, tx);
5868 
5869                 /* Keeping the origin open increases spa_minref */
5870                 spa->spa_minref += 3;
5871         }
5872 
5873         if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
5874             spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
5875                 dsl_pool_upgrade_clones(dp, tx);
5876         }
5877 
5878         if (spa->spa_ubsync.ub_version < SPA_VERSION_DIR_CLONES &&
5879             spa->spa_uberblock.ub_version >= SPA_VERSION_DIR_CLONES) {
5880                 dsl_pool_upgrade_dir_clones(dp, tx);
5881 
5882                 /* Keeping the freedir open increases spa_minref */
5883                 spa->spa_minref += 3;
5884         }
5885 
5886         if (spa->spa_ubsync.ub_version < SPA_VERSION_FEATURES &&
5887             spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
5888                 spa_feature_create_zap_objects(spa, tx);
5889         }
5890 }
5891 
5892 /*
5893  * Sync the specified transaction group.  New blocks may be dirtied as
5894  * part of the process, so we iterate until it converges.
5895  */
5896 void
5897 spa_sync(spa_t *spa, uint64_t txg)
5898 {
5899         dsl_pool_t *dp = spa->spa_dsl_pool;
5900         objset_t *mos = spa->spa_meta_objset;
5901         bpobj_t *defer_bpo = &spa->spa_deferred_bpobj;
5902         bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
5903         vdev_t *rvd = spa->spa_root_vdev;
5904         vdev_t *vd;
5905         dmu_tx_t *tx;
5906         int error;
5907 
5908         VERIFY(spa_writeable(spa));
5909 
5910         /*
5911          * Lock out configuration changes.
5912          */
5913         spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5914 
5915         spa->spa_syncing_txg = txg;
5916         spa->spa_sync_pass = 0;
5917 
5918         /*
5919          * If there are any pending vdev state changes, convert them
5920          * into config changes that go out with this transaction group.
5921          */
5922         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5923         while (list_head(&spa->spa_state_dirty_list) != NULL) {
5924                 /*
5925                  * We need the write lock here because, for aux vdevs,
5926                  * calling vdev_config_dirty() modifies sav_config.
5927                  * This is ugly and will become unnecessary when we
5928                  * eliminate the aux vdev wart by integrating all vdevs
5929                  * into the root vdev tree.
5930                  */
5931                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
5932                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
5933                 while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
5934                         vdev_state_clean(vd);
5935                         vdev_config_dirty(vd);
5936                 }
5937                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
5938                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
5939         }
5940         spa_config_exit(spa, SCL_STATE, FTAG);
5941 
5942         tx = dmu_tx_create_assigned(dp, txg);
5943 
5944         /*
5945          * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
5946          * set spa_deflate if we have no raid-z vdevs.
5947          */
5948         if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
5949             spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
5950                 int i;
5951 
5952                 for (i = 0; i < rvd->vdev_children; i++) {
5953                         vd = rvd->vdev_child[i];
5954                         if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
5955                                 break;
5956                 }
5957                 if (i == rvd->vdev_children) {
5958                         spa->spa_deflate = TRUE;
5959                         VERIFY(0 == zap_add(spa->spa_meta_objset,
5960                             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
5961                             sizeof (uint64_t), 1, &spa->spa_deflate, tx));
5962                 }
5963         }
5964 
5965         /*
5966          * If anything has changed in this txg, or if someone is waiting
5967          * for this txg to sync (eg, spa_vdev_remove()), push the
5968          * deferred frees from the previous txg.  If not, leave them
5969          * alone so that we don't generate work on an otherwise idle
5970          * system.
5971          */
5972         if (!txg_list_empty(&dp->dp_dirty_datasets, txg) ||
5973             !txg_list_empty(&dp->dp_dirty_dirs, txg) ||
5974             !txg_list_empty(&dp->dp_sync_tasks, txg) ||
5975             ((dsl_scan_active(dp->dp_scan) ||
5976             txg_sync_waiting(dp)) && !spa_shutting_down(spa))) {
5977                 zio_t *zio = zio_root(spa, NULL, NULL, 0);
5978                 VERIFY3U(bpobj_iterate(defer_bpo,
5979                     spa_free_sync_cb, zio, tx), ==, 0);
5980                 VERIFY3U(zio_wait(zio), ==, 0);
5981         }
5982 
5983         /*
5984          * Iterate to convergence.
5985          */
5986         do {
5987                 int pass = ++spa->spa_sync_pass;
5988 
5989                 spa_sync_config_object(spa, tx);
5990                 spa_sync_aux_dev(spa, &spa->spa_spares, tx,
5991                     ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
5992                 spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
5993                     ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
5994                 spa_errlog_sync(spa, txg);
5995                 dsl_pool_sync(dp, txg);
5996 
5997                 if (pass <= SYNC_PASS_DEFERRED_FREE) {
5998                         zio_t *zio = zio_root(spa, NULL, NULL, 0);
5999                         bplist_iterate(free_bpl, spa_free_sync_cb,
6000                             zio, tx);
6001                         VERIFY(zio_wait(zio) == 0);
6002                 } else {
6003                         bplist_iterate(free_bpl, bpobj_enqueue_cb,
6004                             defer_bpo, tx);
6005                 }
6006 
6007                 ddt_sync(spa, txg);
6008                 dsl_scan_sync(dp, tx);
6009 
6010                 while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
6011                         vdev_sync(vd, txg);
6012 
6013                 if (pass == 1)
6014                         spa_sync_upgrades(spa, tx);
6015 
6016         } while (dmu_objset_is_dirty(mos, txg));
6017 
6018         /*
6019          * Rewrite the vdev configuration (which includes the uberblock)
6020          * to commit the transaction group.
6021          *
6022          * If there are no dirty vdevs, we sync the uberblock to a few
6023          * random top-level vdevs that are known to be visible in the
6024          * config cache (see spa_vdev_add() for a complete description).
6025          * If there *are* dirty vdevs, sync the uberblock to all vdevs.
6026          */
6027         for (;;) {
6028                 /*
6029                  * We hold SCL_STATE to prevent vdev open/close/etc.
6030                  * while we're attempting to write the vdev labels.
6031                  */
6032                 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6033 
6034                 if (list_is_empty(&spa->spa_config_dirty_list)) {
6035                         vdev_t *svd[SPA_DVAS_PER_BP];
6036                         int svdcount = 0;
6037                         int children = rvd->vdev_children;
6038                         int c0 = spa_get_random(children);
6039 
6040                         for (int c = 0; c < children; c++) {
6041                                 vd = rvd->vdev_child[(c0 + c) % children];
6042                                 if (vd->vdev_ms_array == 0 || vd->vdev_islog)
6043                                         continue;
6044                                 svd[svdcount++] = vd;
6045                                 if (svdcount == SPA_DVAS_PER_BP)
6046                                         break;
6047                         }
6048                         error = vdev_config_sync(svd, svdcount, txg, B_FALSE);
6049                         if (error != 0)
6050                                 error = vdev_config_sync(svd, svdcount, txg,
6051                                     B_TRUE);
6052                 } else {
6053                         error = vdev_config_sync(rvd->vdev_child,
6054                             rvd->vdev_children, txg, B_FALSE);
6055                         if (error != 0)
6056                                 error = vdev_config_sync(rvd->vdev_child,
6057                                     rvd->vdev_children, txg, B_TRUE);
6058                 }
6059 
6060                 spa_config_exit(spa, SCL_STATE, FTAG);
6061 
6062                 if (error == 0)
6063                         break;
6064                 zio_suspend(spa, NULL);
6065                 zio_resume_wait(spa);
6066         }
6067         dmu_tx_commit(tx);
6068 
6069         /*
6070          * Clear the dirty config list.
6071          */
6072         while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
6073                 vdev_config_clean(vd);
6074 
6075         /*
6076          * Now that the new config has synced transactionally,
6077          * let it become visible to the config cache.
6078          */
6079         if (spa->spa_config_syncing != NULL) {
6080                 spa_config_set(spa, spa->spa_config_syncing);
6081                 spa->spa_config_txg = txg;
6082                 spa->spa_config_syncing = NULL;
6083         }
6084 
6085         spa->spa_ubsync = spa->spa_uberblock;
6086 
6087         dsl_pool_sync_done(dp, txg);
6088 
6089         /*
6090          * Update usable space statistics.
6091          */
6092         while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
6093                 vdev_sync_done(vd, txg);
6094 
6095         spa_update_dspace(spa);
6096 
6097         /*
6098          * It had better be the case that we didn't dirty anything
6099          * since vdev_config_sync().
6100          */
6101         ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
6102         ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
6103         ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
6104 
6105         spa->spa_sync_pass = 0;
6106 
6107         spa_config_exit(spa, SCL_CONFIG, FTAG);
6108 
6109         spa_handle_ignored_writes(spa);
6110 
6111         /*
6112          * If any async tasks have been requested, kick them off.
6113          */
6114         spa_async_dispatch(spa);
6115 }
6116 
6117 /*
6118  * Sync all pools.  We don't want to hold the namespace lock across these
6119  * operations, so we take a reference on the spa_t and drop the lock during the
6120  * sync.
6121  */
6122 void
6123 spa_sync_allpools(void)
6124 {
6125         spa_t *spa = NULL;
6126         mutex_enter(&spa_namespace_lock);
6127         while ((spa = spa_next(spa)) != NULL) {
6128                 if (spa_state(spa) != POOL_STATE_ACTIVE ||
6129                     !spa_writeable(spa) || spa_suspended(spa))
6130                         continue;
6131                 spa_open_ref(spa, FTAG);
6132                 mutex_exit(&spa_namespace_lock);
6133                 txg_wait_synced(spa_get_dsl(spa), 0);
6134                 mutex_enter(&spa_namespace_lock);
6135                 spa_close(spa, FTAG);
6136         }
6137         mutex_exit(&spa_namespace_lock);
6138 }
6139 
6140 /*
6141  * ==========================================================================
6142  * Miscellaneous routines
6143  * ==========================================================================
6144  */
6145 
6146 /*
6147  * Remove all pools in the system.
6148  */
6149 void
6150 spa_evict_all(void)
6151 {
6152         spa_t *spa;
6153 
6154         /*
6155          * Remove all cached state.  All pools should be closed now,
6156          * so every spa in the AVL tree should be unreferenced.
6157          */
6158         mutex_enter(&spa_namespace_lock);
6159         while ((spa = spa_next(NULL)) != NULL) {
6160                 /*
6161                  * Stop async tasks.  The async thread may need to detach
6162                  * a device that's been replaced, which requires grabbing
6163                  * spa_namespace_lock, so we must drop it here.
6164                  */
6165                 spa_open_ref(spa, FTAG);
6166                 mutex_exit(&spa_namespace_lock);
6167                 spa_async_suspend(spa);
6168                 mutex_enter(&spa_namespace_lock);
6169                 spa_close(spa, FTAG);
6170 
6171                 if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
6172                         spa_unload(spa);
6173                         spa_deactivate(spa);
6174                 }
6175                 spa_remove(spa);
6176         }
6177         mutex_exit(&spa_namespace_lock);
6178 }
6179 
6180 vdev_t *
6181 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
6182 {
6183         vdev_t *vd;
6184         int i;
6185 
6186         if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
6187                 return (vd);
6188 
6189         if (aux) {
6190                 for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
6191                         vd = spa->spa_l2cache.sav_vdevs[i];
6192                         if (vd->vdev_guid == guid)
6193                                 return (vd);
6194                 }
6195 
6196                 for (i = 0; i < spa->spa_spares.sav_count; i++) {
6197                         vd = spa->spa_spares.sav_vdevs[i];
6198                         if (vd->vdev_guid == guid)
6199                                 return (vd);
6200                 }
6201         }
6202 
6203         return (NULL);
6204 }
6205 
6206 void
6207 spa_upgrade(spa_t *spa, uint64_t version)
6208 {
6209         ASSERT(spa_writeable(spa));
6210 
6211         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6212 
6213         /*
6214          * This should only be called for a non-faulted pool, and since a
6215          * future version would result in an unopenable pool, this shouldn't be
6216          * possible.
6217          */
6218         ASSERT(spa->spa_uberblock.ub_version <= SPA_VERSION);
6219         ASSERT(version >= spa->spa_uberblock.ub_version);
6220 
6221         spa->spa_uberblock.ub_version = version;
6222         vdev_config_dirty(spa->spa_root_vdev);
6223 
6224         spa_config_exit(spa, SCL_ALL, FTAG);
6225 
6226         txg_wait_synced(spa_get_dsl(spa), 0);
6227 }
6228 
6229 boolean_t
6230 spa_has_spare(spa_t *spa, uint64_t guid)
6231 {
6232         int i;
6233         uint64_t spareguid;
6234         spa_aux_vdev_t *sav = &spa->spa_spares;
6235 
6236         for (i = 0; i < sav->sav_count; i++)
6237                 if (sav->sav_vdevs[i]->vdev_guid == guid)
6238                         return (B_TRUE);
6239 
6240         for (i = 0; i < sav->sav_npending; i++) {
6241                 if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
6242                     &spareguid) == 0 && spareguid == guid)
6243                         return (B_TRUE);
6244         }
6245 
6246         return (B_FALSE);
6247 }
6248 
6249 /*
6250  * Check if a pool has an active shared spare device.
6251  * Note: reference count of an active spare is 2, as a spare and as a replace
6252  */
6253 static boolean_t
6254 spa_has_active_shared_spare(spa_t *spa)
6255 {
6256         int i, refcnt;
6257         uint64_t pool;
6258         spa_aux_vdev_t *sav = &spa->spa_spares;
6259 
6260         for (i = 0; i < sav->sav_count; i++) {
6261                 if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
6262                     &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
6263                     refcnt > 2)
6264                         return (B_TRUE);
6265         }
6266 
6267         return (B_FALSE);
6268 }
6269 
6270 /*
6271  * Post a sysevent corresponding to the given event.  The 'name' must be one of
6272  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
6273  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
6274  * in the userland libzpool, as we don't want consumers to misinterpret ztest
6275  * or zdb as real changes.
6276  */
6277 void
6278 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
6279 {
6280 #ifdef _KERNEL
6281         sysevent_t              *ev;
6282         sysevent_attr_list_t    *attr = NULL;
6283         sysevent_value_t        value;
6284         sysevent_id_t           eid;
6285 
6286         ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
6287             SE_SLEEP);
6288 
6289         value.value_type = SE_DATA_TYPE_STRING;
6290         value.value.sv_string = spa_name(spa);
6291         if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
6292                 goto done;
6293 
6294         value.value_type = SE_DATA_TYPE_UINT64;
6295         value.value.sv_uint64 = spa_guid(spa);
6296         if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
6297                 goto done;
6298 
6299         if (vd) {
6300                 value.value_type = SE_DATA_TYPE_UINT64;
6301                 value.value.sv_uint64 = vd->vdev_guid;
6302                 if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
6303                     SE_SLEEP) != 0)
6304                         goto done;
6305 
6306                 if (vd->vdev_path) {
6307                         value.value_type = SE_DATA_TYPE_STRING;
6308                         value.value.sv_string = vd->vdev_path;
6309                         if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
6310                             &value, SE_SLEEP) != 0)
6311                                 goto done;
6312                 }
6313         }
6314 
6315         if (sysevent_attach_attributes(ev, attr) != 0)
6316                 goto done;
6317         attr = NULL;
6318 
6319         (void) log_sysevent(ev, SE_SLEEP, &eid);
6320 
6321 done:
6322         if (attr)
6323                 sysevent_free_attr(attr);
6324         sysevent_free(ev);
6325 #endif
6326 }