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) 2011 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 
  66 #ifdef  _KERNEL
  67 #include <sys/bootprops.h>
  68 #include <sys/callb.h>
  69 #include <sys/cpupart.h>
  70 #include <sys/pool.h>
  71 #include <sys/sysdc.h>
  72 #include <sys/zone.h>
  73 #endif  /* _KERNEL */
  74 
  75 #include "zfs_prop.h"
  76 #include "zfs_comutil.h"
  77 
  78 typedef enum zti_modes {
  79         zti_mode_fixed,                 /* value is # of threads (min 1) */
  80         zti_mode_online_percent,        /* value is % of online CPUs */
  81         zti_mode_batch,                 /* cpu-intensive; value is ignored */
  82         zti_mode_null,                  /* don't create a taskq */
  83         zti_nmodes
  84 } zti_modes_t;
  85 
  86 #define ZTI_FIX(n)      { zti_mode_fixed, (n) }
  87 #define ZTI_PCT(n)      { zti_mode_online_percent, (n) }
  88 #define ZTI_BATCH       { zti_mode_batch, 0 }
  89 #define ZTI_NULL        { zti_mode_null, 0 }
  90 
  91 #define ZTI_ONE         ZTI_FIX(1)
  92 
  93 typedef struct zio_taskq_info {
  94         enum zti_modes zti_mode;
  95         uint_t zti_value;
  96 } zio_taskq_info_t;
  97 
  98 static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
  99         "issue", "issue_high", "intr", "intr_high"
 100 };
 101 
 102 /*
 103  * Define the taskq threads for the following I/O types:
 104  *      NULL, READ, WRITE, FREE, CLAIM, and IOCTL
 105  */
 106 const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
 107         /* ISSUE        ISSUE_HIGH      INTR            INTR_HIGH */
 108         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL },
 109         { ZTI_FIX(8),   ZTI_NULL,       ZTI_BATCH,      ZTI_NULL },
 110         { ZTI_BATCH,    ZTI_FIX(5),     ZTI_FIX(8),     ZTI_FIX(5) },
 111         { ZTI_FIX(100), ZTI_NULL,       ZTI_ONE,        ZTI_NULL },
 112         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL },
 113         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL },
 114 };
 115 
 116 static dsl_syncfunc_t spa_sync_props;
 117 static boolean_t spa_has_active_shared_spare(spa_t *spa);
 118 static int spa_load_impl(spa_t *spa, uint64_t, nvlist_t *config,
 119     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
 120     char **ereport);
 121 static void spa_vdev_resilver_done(spa_t *spa);
 122 
 123 uint_t          zio_taskq_batch_pct = 100;      /* 1 thread per cpu in pset */
 124 id_t            zio_taskq_psrset_bind = PS_NONE;
 125 boolean_t       zio_taskq_sysdc = B_TRUE;       /* use SDC scheduling class */
 126 uint_t          zio_taskq_basedc = 80;          /* base duty cycle */
 127 
 128 boolean_t       spa_create_process = B_TRUE;    /* no process ==> no sysdc */
 129 
 130 /*
 131  * This (illegal) pool name is used when temporarily importing a spa_t in order
 132  * to get the vdev stats associated with the imported devices.
 133  */
 134 #define TRYIMPORT_NAME  "$import"
 135 
 136 /*
 137  * ==========================================================================
 138  * SPA properties routines
 139  * ==========================================================================
 140  */
 141 
 142 /*
 143  * Add a (source=src, propname=propval) list to an nvlist.
 144  */
 145 static void
 146 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, char *strval,
 147     uint64_t intval, zprop_source_t src)
 148 {
 149         const char *propname = zpool_prop_to_name(prop);
 150         nvlist_t *propval;
 151 
 152         VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 153         VERIFY(nvlist_add_uint64(propval, ZPROP_SOURCE, src) == 0);
 154 
 155         if (strval != NULL)
 156                 VERIFY(nvlist_add_string(propval, ZPROP_VALUE, strval) == 0);
 157         else
 158                 VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, intval) == 0);
 159 
 160         VERIFY(nvlist_add_nvlist(nvl, propname, propval) == 0);
 161         nvlist_free(propval);
 162 }
 163 
 164 /*
 165  * Get property values from the spa configuration.
 166  */
 167 static void
 168 spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
 169 {
 170         uint64_t size;
 171         uint64_t alloc;
 172         uint64_t cap, version;
 173         zprop_source_t src = ZPROP_SRC_NONE;
 174         spa_config_dirent_t *dp;
 175 
 176         ASSERT(MUTEX_HELD(&spa->spa_props_lock));
 177 
 178         if (spa->spa_root_vdev != NULL) {
 179                 alloc = metaslab_class_get_alloc(spa_normal_class(spa));
 180                 size = metaslab_class_get_space(spa_normal_class(spa));
 181                 spa_prop_add_list(*nvp, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
 182                 spa_prop_add_list(*nvp, ZPOOL_PROP_SIZE, NULL, size, src);
 183                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALLOCATED, NULL, alloc, src);
 184                 spa_prop_add_list(*nvp, ZPOOL_PROP_FREE, NULL,
 185                     size - alloc, src);
 186                 spa_prop_add_list(*nvp, ZPOOL_PROP_READONLY, NULL,
 187                     (spa_mode(spa) == FREAD), src);
 188 
 189                 cap = (size == 0) ? 0 : (alloc * 100 / size);
 190                 spa_prop_add_list(*nvp, ZPOOL_PROP_CAPACITY, NULL, cap, src);
 191 
 192                 spa_prop_add_list(*nvp, ZPOOL_PROP_DEDUPRATIO, NULL,
 193                     ddt_get_pool_dedup_ratio(spa), src);
 194 
 195                 spa_prop_add_list(*nvp, ZPOOL_PROP_HEALTH, NULL,
 196                     spa->spa_root_vdev->vdev_state, src);
 197 
 198                 version = spa_version(spa);
 199                 if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION))
 200                         src = ZPROP_SRC_DEFAULT;
 201                 else
 202                         src = ZPROP_SRC_LOCAL;
 203                 spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL, version, src);
 204         }
 205 
 206         spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
 207 
 208         if (spa->spa_root != NULL)
 209                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
 210                     0, ZPROP_SRC_LOCAL);
 211 
 212         if ((dp = list_head(&spa->spa_config_list)) != NULL) {
 213                 if (dp->scd_path == NULL) {
 214                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 215                             "none", 0, ZPROP_SRC_LOCAL);
 216                 } else if (strcmp(dp->scd_path, spa_config_path) != 0) {
 217                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 218                             dp->scd_path, 0, ZPROP_SRC_LOCAL);
 219                 }
 220         }
 221 }
 222 
 223 /*
 224  * Get zpool property values.
 225  */
 226 int
 227 spa_prop_get(spa_t *spa, nvlist_t **nvp)
 228 {
 229         objset_t *mos = spa->spa_meta_objset;
 230         zap_cursor_t zc;
 231         zap_attribute_t za;
 232         int err;
 233 
 234         VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 235 
 236         mutex_enter(&spa->spa_props_lock);
 237 
 238         /*
 239          * Get properties from the spa config.
 240          */
 241         spa_prop_get_config(spa, nvp);
 242 
 243         /* If no pool property object, no more prop to get. */
 244         if (mos == NULL || spa->spa_pool_props_object == 0) {
 245                 mutex_exit(&spa->spa_props_lock);
 246                 return (0);
 247         }
 248 
 249         /*
 250          * Get properties from the MOS pool property object.
 251          */
 252         for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
 253             (err = zap_cursor_retrieve(&zc, &za)) == 0;
 254             zap_cursor_advance(&zc)) {
 255                 uint64_t intval = 0;
 256                 char *strval = NULL;
 257                 zprop_source_t src = ZPROP_SRC_DEFAULT;
 258                 zpool_prop_t prop;
 259 
 260                 if ((prop = zpool_name_to_prop(za.za_name)) == ZPROP_INVAL)
 261                         continue;
 262 
 263                 switch (za.za_integer_length) {
 264                 case 8:
 265                         /* integer property */
 266                         if (za.za_first_integer !=
 267                             zpool_prop_default_numeric(prop))
 268                                 src = ZPROP_SRC_LOCAL;
 269 
 270                         if (prop == ZPOOL_PROP_BOOTFS) {
 271                                 dsl_pool_t *dp;
 272                                 dsl_dataset_t *ds = NULL;
 273 
 274                                 dp = spa_get_dsl(spa);
 275                                 rw_enter(&dp->dp_config_rwlock, RW_READER);
 276                                 if (err = dsl_dataset_hold_obj(dp,
 277                                     za.za_first_integer, FTAG, &ds)) {
 278                                         rw_exit(&dp->dp_config_rwlock);
 279                                         break;
 280                                 }
 281 
 282                                 strval = kmem_alloc(
 283                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1,
 284                                     KM_SLEEP);
 285                                 dsl_dataset_name(ds, strval);
 286                                 dsl_dataset_rele(ds, FTAG);
 287                                 rw_exit(&dp->dp_config_rwlock);
 288                         } else {
 289                                 strval = NULL;
 290                                 intval = za.za_first_integer;
 291                         }
 292 
 293                         spa_prop_add_list(*nvp, prop, strval, intval, src);
 294 
 295                         if (strval != NULL)
 296                                 kmem_free(strval,
 297                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1);
 298 
 299                         break;
 300 
 301                 case 1:
 302                         /* string property */
 303                         strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
 304                         err = zap_lookup(mos, spa->spa_pool_props_object,
 305                             za.za_name, 1, za.za_num_integers, strval);
 306                         if (err) {
 307                                 kmem_free(strval, za.za_num_integers);
 308                                 break;
 309                         }
 310                         spa_prop_add_list(*nvp, prop, strval, 0, src);
 311                         kmem_free(strval, za.za_num_integers);
 312                         break;
 313 
 314                 default:
 315                         break;
 316                 }
 317         }
 318         zap_cursor_fini(&zc);
 319         mutex_exit(&spa->spa_props_lock);
 320 out:
 321         if (err && err != ENOENT) {
 322                 nvlist_free(*nvp);
 323                 *nvp = NULL;
 324                 return (err);
 325         }
 326 
 327         return (0);
 328 }
 329 
 330 /*
 331  * Validate the given pool properties nvlist and modify the list
 332  * for the property values to be set.
 333  */
 334 static int
 335 spa_prop_validate(spa_t *spa, nvlist_t *props)
 336 {
 337         nvpair_t *elem;
 338         int error = 0, reset_bootfs = 0;
 339         uint64_t objnum;
 340 
 341         elem = NULL;
 342         while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
 343                 zpool_prop_t prop;
 344                 char *propname, *strval;
 345                 uint64_t intval;
 346                 objset_t *os;
 347                 char *slash;
 348 
 349                 propname = nvpair_name(elem);
 350 
 351                 if ((prop = zpool_name_to_prop(propname)) == ZPROP_INVAL)
 352                         return (EINVAL);
 353 
 354                 switch (prop) {
 355                 case ZPOOL_PROP_VERSION:
 356                         error = nvpair_value_uint64(elem, &intval);
 357                         if (!error &&
 358                             (intval < spa_version(spa) || intval > SPA_VERSION))
 359                                 error = EINVAL;
 360                         break;
 361 
 362                 case ZPOOL_PROP_DELEGATION:
 363                 case ZPOOL_PROP_AUTOREPLACE:
 364                 case ZPOOL_PROP_LISTSNAPS:
 365                 case ZPOOL_PROP_AUTOEXPAND:
 366                         error = nvpair_value_uint64(elem, &intval);
 367                         if (!error && intval > 1)
 368                                 error = EINVAL;
 369                         break;
 370 
 371                 case ZPOOL_PROP_BOOTFS:
 372                         /*
 373                          * If the pool version is less than SPA_VERSION_BOOTFS,
 374                          * or the pool is still being created (version == 0),
 375                          * the bootfs property cannot be set.
 376                          */
 377                         if (spa_version(spa) < SPA_VERSION_BOOTFS) {
 378                                 error = ENOTSUP;
 379                                 break;
 380                         }
 381 
 382                         /*
 383                          * Make sure the vdev config is bootable
 384                          */
 385                         if (!vdev_is_bootable(spa->spa_root_vdev)) {
 386                                 error = ENOTSUP;
 387                                 break;
 388                         }
 389 
 390                         reset_bootfs = 1;
 391 
 392                         error = nvpair_value_string(elem, &strval);
 393 
 394                         if (!error) {
 395                                 uint64_t compress;
 396 
 397                                 if (strval == NULL || strval[0] == '\0') {
 398                                         objnum = zpool_prop_default_numeric(
 399                                             ZPOOL_PROP_BOOTFS);
 400                                         break;
 401                                 }
 402 
 403                                 if (error = dmu_objset_hold(strval, FTAG, &os))
 404                                         break;
 405 
 406                                 /* Must be ZPL and not gzip compressed. */
 407 
 408                                 if (dmu_objset_type(os) != DMU_OST_ZFS) {
 409                                         error = ENOTSUP;
 410                                 } else if ((error = dsl_prop_get_integer(strval,
 411                                     zfs_prop_to_name(ZFS_PROP_COMPRESSION),
 412                                     &compress, NULL)) == 0 &&
 413                                     !BOOTFS_COMPRESS_VALID(compress)) {
 414                                         error = ENOTSUP;
 415                                 } else {
 416                                         objnum = dmu_objset_id(os);
 417                                 }
 418                                 dmu_objset_rele(os, FTAG);
 419                         }
 420                         break;
 421 
 422                 case ZPOOL_PROP_FAILUREMODE:
 423                         error = nvpair_value_uint64(elem, &intval);
 424                         if (!error && (intval < ZIO_FAILURE_MODE_WAIT ||
 425                             intval > ZIO_FAILURE_MODE_PANIC))
 426                                 error = EINVAL;
 427 
 428                         /*
 429                          * This is a special case which only occurs when
 430                          * the pool has completely failed. This allows
 431                          * the user to change the in-core failmode property
 432                          * without syncing it out to disk (I/Os might
 433                          * currently be blocked). We do this by returning
 434                          * EIO to the caller (spa_prop_set) to trick it
 435                          * into thinking we encountered a property validation
 436                          * error.
 437                          */
 438                         if (!error && spa_suspended(spa)) {
 439                                 spa->spa_failmode = intval;
 440                                 error = EIO;
 441                         }
 442                         break;
 443 
 444                 case ZPOOL_PROP_CACHEFILE:
 445                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 446                                 break;
 447 
 448                         if (strval[0] == '\0')
 449                                 break;
 450 
 451                         if (strcmp(strval, "none") == 0)
 452                                 break;
 453 
 454                         if (strval[0] != '/') {
 455                                 error = EINVAL;
 456                                 break;
 457                         }
 458 
 459                         slash = strrchr(strval, '/');
 460                         ASSERT(slash != NULL);
 461 
 462                         if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
 463                             strcmp(slash, "/..") == 0)
 464                                 error = EINVAL;
 465                         break;
 466 
 467                 case ZPOOL_PROP_DEDUPDITTO:
 468                         if (spa_version(spa) < SPA_VERSION_DEDUP)
 469                                 error = ENOTSUP;
 470                         else
 471                                 error = nvpair_value_uint64(elem, &intval);
 472                         if (error == 0 &&
 473                             intval != 0 && intval < ZIO_DEDUPDITTO_MIN)
 474                                 error = EINVAL;
 475                         break;
 476                 }
 477 
 478                 if (error)
 479                         break;
 480         }
 481 
 482         if (!error && reset_bootfs) {
 483                 error = nvlist_remove(props,
 484                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
 485 
 486                 if (!error) {
 487                         error = nvlist_add_uint64(props,
 488                             zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
 489                 }
 490         }
 491 
 492         return (error);
 493 }
 494 
 495 void
 496 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
 497 {
 498         char *cachefile;
 499         spa_config_dirent_t *dp;
 500 
 501         if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
 502             &cachefile) != 0)
 503                 return;
 504 
 505         dp = kmem_alloc(sizeof (spa_config_dirent_t),
 506             KM_SLEEP);
 507 
 508         if (cachefile[0] == '\0')
 509                 dp->scd_path = spa_strdup(spa_config_path);
 510         else if (strcmp(cachefile, "none") == 0)
 511                 dp->scd_path = NULL;
 512         else
 513                 dp->scd_path = spa_strdup(cachefile);
 514 
 515         list_insert_head(&spa->spa_config_list, dp);
 516         if (need_sync)
 517                 spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
 518 }
 519 
 520 int
 521 spa_prop_set(spa_t *spa, nvlist_t *nvp)
 522 {
 523         int error;
 524         nvpair_t *elem;
 525         boolean_t need_sync = B_FALSE;
 526         zpool_prop_t prop;
 527 
 528         if ((error = spa_prop_validate(spa, nvp)) != 0)
 529                 return (error);
 530 
 531         elem = NULL;
 532         while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
 533                 if ((prop = zpool_name_to_prop(
 534                     nvpair_name(elem))) == ZPROP_INVAL)
 535                         return (EINVAL);
 536 
 537                 if (prop == ZPOOL_PROP_CACHEFILE ||
 538                     prop == ZPOOL_PROP_ALTROOT ||
 539                     prop == ZPOOL_PROP_READONLY)
 540                         continue;
 541 
 542                 need_sync = B_TRUE;
 543                 break;
 544         }
 545 
 546         if (need_sync)
 547                 return (dsl_sync_task_do(spa_get_dsl(spa), NULL, spa_sync_props,
 548                     spa, nvp, 3));
 549         else
 550                 return (0);
 551 }
 552 
 553 /*
 554  * If the bootfs property value is dsobj, clear it.
 555  */
 556 void
 557 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
 558 {
 559         if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
 560                 VERIFY(zap_remove(spa->spa_meta_objset,
 561                     spa->spa_pool_props_object,
 562                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
 563                 spa->spa_bootfs = 0;
 564         }
 565 }
 566 
 567 /*
 568  * Change the GUID for the pool.  This is done so that we can later
 569  * re-import a pool built from a clone of our own vdevs.  We will modify
 570  * the root vdev's guid, our own pool guid, and then mark all of our
 571  * vdevs dirty.  Note that we must make sure that all our vdevs are
 572  * online when we do this, or else any vdevs that weren't present
 573  * would be orphaned from our pool.  We are also going to issue a
 574  * sysevent to update any watchers.
 575  */
 576 int
 577 spa_change_guid(spa_t *spa)
 578 {
 579         uint64_t        oldguid, newguid;
 580         uint64_t        txg;
 581 
 582         if (!(spa_mode_global & FWRITE))
 583                 return (EROFS);
 584 
 585         txg = spa_vdev_enter(spa);
 586 
 587         if (spa->spa_root_vdev->vdev_state != VDEV_STATE_HEALTHY)
 588                 return (spa_vdev_exit(spa, NULL, txg, ENXIO));
 589 
 590         oldguid = spa_guid(spa);
 591         newguid = spa_generate_guid(NULL);
 592         ASSERT3U(oldguid, !=, newguid);
 593 
 594         spa->spa_root_vdev->vdev_guid = newguid;
 595         spa->spa_root_vdev->vdev_guid_sum += (newguid - oldguid);
 596 
 597         vdev_config_dirty(spa->spa_root_vdev);
 598 
 599         spa_event_notify(spa, NULL, ESC_ZFS_POOL_REGUID);
 600 
 601         return (spa_vdev_exit(spa, NULL, txg, 0));
 602 }
 603 
 604 /*
 605  * ==========================================================================
 606  * SPA state manipulation (open/create/destroy/import/export)
 607  * ==========================================================================
 608  */
 609 
 610 static int
 611 spa_error_entry_compare(const void *a, const void *b)
 612 {
 613         spa_error_entry_t *sa = (spa_error_entry_t *)a;
 614         spa_error_entry_t *sb = (spa_error_entry_t *)b;
 615         int ret;
 616 
 617         ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
 618             sizeof (zbookmark_t));
 619 
 620         if (ret < 0)
 621                 return (-1);
 622         else if (ret > 0)
 623                 return (1);
 624         else
 625                 return (0);
 626 }
 627 
 628 /*
 629  * Utility function which retrieves copies of the current logs and
 630  * re-initializes them in the process.
 631  */
 632 void
 633 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
 634 {
 635         ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
 636 
 637         bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
 638         bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));
 639 
 640         avl_create(&spa->spa_errlist_scrub,
 641             spa_error_entry_compare, sizeof (spa_error_entry_t),
 642             offsetof(spa_error_entry_t, se_avl));
 643         avl_create(&spa->spa_errlist_last,
 644             spa_error_entry_compare, sizeof (spa_error_entry_t),
 645             offsetof(spa_error_entry_t, se_avl));
 646 }
 647 
 648 static taskq_t *
 649 spa_taskq_create(spa_t *spa, const char *name, enum zti_modes mode,
 650     uint_t value)
 651 {
 652         uint_t flags = 0;
 653         boolean_t batch = B_FALSE;
 654 
 655         switch (mode) {
 656         case zti_mode_null:
 657                 return (NULL);          /* no taskq needed */
 658 
 659         case zti_mode_fixed:
 660                 ASSERT3U(value, >=, 1);
 661                 value = MAX(value, 1);
 662                 break;
 663 
 664         case zti_mode_batch:
 665                 batch = B_TRUE;
 666                 flags |= TASKQ_THREADS_CPU_PCT;
 667                 value = zio_taskq_batch_pct;
 668                 break;
 669 
 670         case zti_mode_online_percent:
 671                 flags |= TASKQ_THREADS_CPU_PCT;
 672                 break;
 673 
 674         default:
 675                 panic("unrecognized mode for %s taskq (%u:%u) in "
 676                     "spa_activate()",
 677                     name, mode, value);
 678                 break;
 679         }
 680 
 681         if (zio_taskq_sysdc && spa->spa_proc != &p0) {
 682                 if (batch)
 683                         flags |= TASKQ_DC_BATCH;
 684 
 685                 return (taskq_create_sysdc(name, value, 50, INT_MAX,
 686                     spa->spa_proc, zio_taskq_basedc, flags));
 687         }
 688         return (taskq_create_proc(name, value, maxclsyspri, 50, INT_MAX,
 689             spa->spa_proc, flags));
 690 }
 691 
 692 static void
 693 spa_create_zio_taskqs(spa_t *spa)
 694 {
 695         for (int t = 0; t < ZIO_TYPES; t++) {
 696                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
 697                         const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
 698                         enum zti_modes mode = ztip->zti_mode;
 699                         uint_t value = ztip->zti_value;
 700                         char name[32];
 701 
 702                         (void) snprintf(name, sizeof (name),
 703                             "%s_%s", zio_type_name[t], zio_taskq_types[q]);
 704 
 705                         spa->spa_zio_taskq[t][q] =
 706                             spa_taskq_create(spa, name, mode, value);
 707                 }
 708         }
 709 }
 710 
 711 #ifdef _KERNEL
 712 static void
 713 spa_thread(void *arg)
 714 {
 715         callb_cpr_t cprinfo;
 716 
 717         spa_t *spa = arg;
 718         user_t *pu = PTOU(curproc);
 719 
 720         CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
 721             spa->spa_name);
 722 
 723         ASSERT(curproc != &p0);
 724         (void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
 725             "zpool-%s", spa->spa_name);
 726         (void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
 727 
 728         /* bind this thread to the requested psrset */
 729         if (zio_taskq_psrset_bind != PS_NONE) {
 730                 pool_lock();
 731                 mutex_enter(&cpu_lock);
 732                 mutex_enter(&pidlock);
 733                 mutex_enter(&curproc->p_lock);
 734 
 735                 if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
 736                     0, NULL, NULL) == 0)  {
 737                         curthread->t_bind_pset = zio_taskq_psrset_bind;
 738                 } else {
 739                         cmn_err(CE_WARN,
 740                             "Couldn't bind process for zfs pool \"%s\" to "
 741                             "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
 742                 }
 743 
 744                 mutex_exit(&curproc->p_lock);
 745                 mutex_exit(&pidlock);
 746                 mutex_exit(&cpu_lock);
 747                 pool_unlock();
 748         }
 749 
 750         if (zio_taskq_sysdc) {
 751                 sysdc_thread_enter(curthread, 100, 0);
 752         }
 753 
 754         spa->spa_proc = curproc;
 755         spa->spa_did = curthread->t_did;
 756 
 757         spa_create_zio_taskqs(spa);
 758 
 759         mutex_enter(&spa->spa_proc_lock);
 760         ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
 761 
 762         spa->spa_proc_state = SPA_PROC_ACTIVE;
 763         cv_broadcast(&spa->spa_proc_cv);
 764 
 765         CALLB_CPR_SAFE_BEGIN(&cprinfo);
 766         while (spa->spa_proc_state == SPA_PROC_ACTIVE)
 767                 cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
 768         CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
 769 
 770         ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
 771         spa->spa_proc_state = SPA_PROC_GONE;
 772         spa->spa_proc = &p0;
 773         cv_broadcast(&spa->spa_proc_cv);
 774         CALLB_CPR_EXIT(&cprinfo);   /* drops spa_proc_lock */
 775 
 776         mutex_enter(&curproc->p_lock);
 777         lwp_exit();
 778 }
 779 #endif
 780 
 781 /*
 782  * Activate an uninitialized pool.
 783  */
 784 static void
 785 spa_activate(spa_t *spa, int mode)
 786 {
 787         ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
 788 
 789         spa->spa_state = POOL_STATE_ACTIVE;
 790         spa->spa_mode = mode;
 791 
 792         spa->spa_normal_class = metaslab_class_create(spa, zfs_metaslab_ops);
 793         spa->spa_log_class = metaslab_class_create(spa, zfs_metaslab_ops);
 794 
 795         /* Try to create a covering process */
 796         mutex_enter(&spa->spa_proc_lock);
 797         ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
 798         ASSERT(spa->spa_proc == &p0);
 799         spa->spa_did = 0;
 800 
 801         /* Only create a process if we're going to be around a while. */
 802         if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
 803                 if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
 804                     NULL, 0) == 0) {
 805                         spa->spa_proc_state = SPA_PROC_CREATED;
 806                         while (spa->spa_proc_state == SPA_PROC_CREATED) {
 807                                 cv_wait(&spa->spa_proc_cv,
 808                                     &spa->spa_proc_lock);
 809                         }
 810                         ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
 811                         ASSERT(spa->spa_proc != &p0);
 812                         ASSERT(spa->spa_did != 0);
 813                 } else {
 814 #ifdef _KERNEL
 815                         cmn_err(CE_WARN,
 816                             "Couldn't create process for zfs pool \"%s\"\n",
 817                             spa->spa_name);
 818 #endif
 819                 }
 820         }
 821         mutex_exit(&spa->spa_proc_lock);
 822 
 823         /* If we didn't create a process, we need to create our taskqs. */
 824         if (spa->spa_proc == &p0) {
 825                 spa_create_zio_taskqs(spa);
 826         }
 827 
 828         list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
 829             offsetof(vdev_t, vdev_config_dirty_node));
 830         list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
 831             offsetof(vdev_t, vdev_state_dirty_node));
 832 
 833         txg_list_create(&spa->spa_vdev_txg_list,
 834             offsetof(struct vdev, vdev_txg_node));
 835 
 836         avl_create(&spa->spa_errlist_scrub,
 837             spa_error_entry_compare, sizeof (spa_error_entry_t),
 838             offsetof(spa_error_entry_t, se_avl));
 839         avl_create(&spa->spa_errlist_last,
 840             spa_error_entry_compare, sizeof (spa_error_entry_t),
 841             offsetof(spa_error_entry_t, se_avl));
 842 }
 843 
 844 /*
 845  * Opposite of spa_activate().
 846  */
 847 static void
 848 spa_deactivate(spa_t *spa)
 849 {
 850         ASSERT(spa->spa_sync_on == B_FALSE);
 851         ASSERT(spa->spa_dsl_pool == NULL);
 852         ASSERT(spa->spa_root_vdev == NULL);
 853         ASSERT(spa->spa_async_zio_root == NULL);
 854         ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
 855 
 856         txg_list_destroy(&spa->spa_vdev_txg_list);
 857 
 858         list_destroy(&spa->spa_config_dirty_list);
 859         list_destroy(&spa->spa_state_dirty_list);
 860 
 861         for (int t = 0; t < ZIO_TYPES; t++) {
 862                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
 863                         if (spa->spa_zio_taskq[t][q] != NULL)
 864                                 taskq_destroy(spa->spa_zio_taskq[t][q]);
 865                         spa->spa_zio_taskq[t][q] = NULL;
 866                 }
 867         }
 868 
 869         metaslab_class_destroy(spa->spa_normal_class);
 870         spa->spa_normal_class = NULL;
 871 
 872         metaslab_class_destroy(spa->spa_log_class);
 873         spa->spa_log_class = NULL;
 874 
 875         /*
 876          * If this was part of an import or the open otherwise failed, we may
 877          * still have errors left in the queues.  Empty them just in case.
 878          */
 879         spa_errlog_drain(spa);
 880 
 881         avl_destroy(&spa->spa_errlist_scrub);
 882         avl_destroy(&spa->spa_errlist_last);
 883 
 884         spa->spa_state = POOL_STATE_UNINITIALIZED;
 885 
 886         mutex_enter(&spa->spa_proc_lock);
 887         if (spa->spa_proc_state != SPA_PROC_NONE) {
 888                 ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
 889                 spa->spa_proc_state = SPA_PROC_DEACTIVATE;
 890                 cv_broadcast(&spa->spa_proc_cv);
 891                 while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
 892                         ASSERT(spa->spa_proc != &p0);
 893                         cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
 894                 }
 895                 ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
 896                 spa->spa_proc_state = SPA_PROC_NONE;
 897         }
 898         ASSERT(spa->spa_proc == &p0);
 899         mutex_exit(&spa->spa_proc_lock);
 900 
 901         /*
 902          * We want to make sure spa_thread() has actually exited the ZFS
 903          * module, so that the module can't be unloaded out from underneath
 904          * it.
 905          */
 906         if (spa->spa_did != 0) {
 907                 thread_join(spa->spa_did);
 908                 spa->spa_did = 0;
 909         }
 910 }
 911 
 912 /*
 913  * Verify a pool configuration, and construct the vdev tree appropriately.  This
 914  * will create all the necessary vdevs in the appropriate layout, with each vdev
 915  * in the CLOSED state.  This will prep the pool before open/creation/import.
 916  * All vdev validation is done by the vdev_alloc() routine.
 917  */
 918 static int
 919 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
 920     uint_t id, int atype)
 921 {
 922         nvlist_t **child;
 923         uint_t children;
 924         int error;
 925 
 926         if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
 927                 return (error);
 928 
 929         if ((*vdp)->vdev_ops->vdev_op_leaf)
 930                 return (0);
 931 
 932         error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
 933             &child, &children);
 934 
 935         if (error == ENOENT)
 936                 return (0);
 937 
 938         if (error) {
 939                 vdev_free(*vdp);
 940                 *vdp = NULL;
 941                 return (EINVAL);
 942         }
 943 
 944         for (int c = 0; c < children; c++) {
 945                 vdev_t *vd;
 946                 if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
 947                     atype)) != 0) {
 948                         vdev_free(*vdp);
 949                         *vdp = NULL;
 950                         return (error);
 951                 }
 952         }
 953 
 954         ASSERT(*vdp != NULL);
 955 
 956         return (0);
 957 }
 958 
 959 /*
 960  * Opposite of spa_load().
 961  */
 962 static void
 963 spa_unload(spa_t *spa)
 964 {
 965         int i;
 966 
 967         ASSERT(MUTEX_HELD(&spa_namespace_lock));
 968 
 969         /*
 970          * Stop async tasks.
 971          */
 972         spa_async_suspend(spa);
 973 
 974         /*
 975          * Stop syncing.
 976          */
 977         if (spa->spa_sync_on) {
 978                 txg_sync_stop(spa->spa_dsl_pool);
 979                 spa->spa_sync_on = B_FALSE;
 980         }
 981 
 982         /*
 983          * Wait for any outstanding async I/O to complete.
 984          */
 985         if (spa->spa_async_zio_root != NULL) {
 986                 (void) zio_wait(spa->spa_async_zio_root);
 987                 spa->spa_async_zio_root = NULL;
 988         }
 989 
 990         bpobj_close(&spa->spa_deferred_bpobj);
 991 
 992         /*
 993          * Close the dsl pool.
 994          */
 995         if (spa->spa_dsl_pool) {
 996                 dsl_pool_close(spa->spa_dsl_pool);
 997                 spa->spa_dsl_pool = NULL;
 998                 spa->spa_meta_objset = NULL;
 999         }
1000 
1001         ddt_unload(spa);
1002 
1003         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1004 
1005         /*
1006          * Drop and purge level 2 cache
1007          */
1008         spa_l2cache_drop(spa);
1009 
1010         /*
1011          * Close all vdevs.
1012          */
1013         if (spa->spa_root_vdev)
1014                 vdev_free(spa->spa_root_vdev);
1015         ASSERT(spa->spa_root_vdev == NULL);
1016 
1017         for (i = 0; i < spa->spa_spares.sav_count; i++)
1018                 vdev_free(spa->spa_spares.sav_vdevs[i]);
1019         if (spa->spa_spares.sav_vdevs) {
1020                 kmem_free(spa->spa_spares.sav_vdevs,
1021                     spa->spa_spares.sav_count * sizeof (void *));
1022                 spa->spa_spares.sav_vdevs = NULL;
1023         }
1024         if (spa->spa_spares.sav_config) {
1025                 nvlist_free(spa->spa_spares.sav_config);
1026                 spa->spa_spares.sav_config = NULL;
1027         }
1028         spa->spa_spares.sav_count = 0;
1029 
1030         for (i = 0; i < spa->spa_l2cache.sav_count; i++)
1031                 vdev_free(spa->spa_l2cache.sav_vdevs[i]);
1032         if (spa->spa_l2cache.sav_vdevs) {
1033                 kmem_free(spa->spa_l2cache.sav_vdevs,
1034                     spa->spa_l2cache.sav_count * sizeof (void *));
1035                 spa->spa_l2cache.sav_vdevs = NULL;
1036         }
1037         if (spa->spa_l2cache.sav_config) {
1038                 nvlist_free(spa->spa_l2cache.sav_config);
1039                 spa->spa_l2cache.sav_config = NULL;
1040         }
1041         spa->spa_l2cache.sav_count = 0;
1042 
1043         spa->spa_async_suspended = 0;
1044 
1045         spa_config_exit(spa, SCL_ALL, FTAG);
1046 }
1047 
1048 /*
1049  * Load (or re-load) the current list of vdevs describing the active spares for
1050  * this pool.  When this is called, we have some form of basic information in
1051  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
1052  * then re-generate a more complete list including status information.
1053  */
1054 static void
1055 spa_load_spares(spa_t *spa)
1056 {
1057         nvlist_t **spares;
1058         uint_t nspares;
1059         int i;
1060         vdev_t *vd, *tvd;
1061 
1062         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1063 
1064         /*
1065          * First, close and free any existing spare vdevs.
1066          */
1067         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1068                 vd = spa->spa_spares.sav_vdevs[i];
1069 
1070                 /* Undo the call to spa_activate() below */
1071                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1072                     B_FALSE)) != NULL && tvd->vdev_isspare)
1073                         spa_spare_remove(tvd);
1074                 vdev_close(vd);
1075                 vdev_free(vd);
1076         }
1077 
1078         if (spa->spa_spares.sav_vdevs)
1079                 kmem_free(spa->spa_spares.sav_vdevs,
1080                     spa->spa_spares.sav_count * sizeof (void *));
1081 
1082         if (spa->spa_spares.sav_config == NULL)
1083                 nspares = 0;
1084         else
1085                 VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1086                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1087 
1088         spa->spa_spares.sav_count = (int)nspares;
1089         spa->spa_spares.sav_vdevs = NULL;
1090 
1091         if (nspares == 0)
1092                 return;
1093 
1094         /*
1095          * Construct the array of vdevs, opening them to get status in the
1096          * process.   For each spare, there is potentially two different vdev_t
1097          * structures associated with it: one in the list of spares (used only
1098          * for basic validation purposes) and one in the active vdev
1099          * configuration (if it's spared in).  During this phase we open and
1100          * validate each vdev on the spare list.  If the vdev also exists in the
1101          * active configuration, then we also mark this vdev as an active spare.
1102          */
1103         spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
1104             KM_SLEEP);
1105         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1106                 VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
1107                     VDEV_ALLOC_SPARE) == 0);
1108                 ASSERT(vd != NULL);
1109 
1110                 spa->spa_spares.sav_vdevs[i] = vd;
1111 
1112                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1113                     B_FALSE)) != NULL) {
1114                         if (!tvd->vdev_isspare)
1115                                 spa_spare_add(tvd);
1116 
1117                         /*
1118                          * We only mark the spare active if we were successfully
1119                          * able to load the vdev.  Otherwise, importing a pool
1120                          * with a bad active spare would result in strange
1121                          * behavior, because multiple pool would think the spare
1122                          * is actively in use.
1123                          *
1124                          * There is a vulnerability here to an equally bizarre
1125                          * circumstance, where a dead active spare is later
1126                          * brought back to life (onlined or otherwise).  Given
1127                          * the rarity of this scenario, and the extra complexity
1128                          * it adds, we ignore the possibility.
1129                          */
1130                         if (!vdev_is_dead(tvd))
1131                                 spa_spare_activate(tvd);
1132                 }
1133 
1134                 vd->vdev_top = vd;
1135                 vd->vdev_aux = &spa->spa_spares;
1136 
1137                 if (vdev_open(vd) != 0)
1138                         continue;
1139 
1140                 if (vdev_validate_aux(vd) == 0)
1141                         spa_spare_add(vd);
1142         }
1143 
1144         /*
1145          * Recompute the stashed list of spares, with status information
1146          * this time.
1147          */
1148         VERIFY(nvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES,
1149             DATA_TYPE_NVLIST_ARRAY) == 0);
1150 
1151         spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
1152             KM_SLEEP);
1153         for (i = 0; i < spa->spa_spares.sav_count; i++)
1154                 spares[i] = vdev_config_generate(spa,
1155                     spa->spa_spares.sav_vdevs[i], B_TRUE, VDEV_CONFIG_SPARE);
1156         VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
1157             ZPOOL_CONFIG_SPARES, spares, spa->spa_spares.sav_count) == 0);
1158         for (i = 0; i < spa->spa_spares.sav_count; i++)
1159                 nvlist_free(spares[i]);
1160         kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
1161 }
1162 
1163 /*
1164  * Load (or re-load) the current list of vdevs describing the active l2cache for
1165  * this pool.  When this is called, we have some form of basic information in
1166  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
1167  * then re-generate a more complete list including status information.
1168  * Devices which are already active have their details maintained, and are
1169  * not re-opened.
1170  */
1171 static void
1172 spa_load_l2cache(spa_t *spa)
1173 {
1174         nvlist_t **l2cache;
1175         uint_t nl2cache;
1176         int i, j, oldnvdevs;
1177         uint64_t guid;
1178         vdev_t *vd, **oldvdevs, **newvdevs;
1179         spa_aux_vdev_t *sav = &spa->spa_l2cache;
1180 
1181         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1182 
1183         if (sav->sav_config != NULL) {
1184                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
1185                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1186                 newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
1187         } else {
1188                 nl2cache = 0;
1189         }
1190 
1191         oldvdevs = sav->sav_vdevs;
1192         oldnvdevs = sav->sav_count;
1193         sav->sav_vdevs = NULL;
1194         sav->sav_count = 0;
1195 
1196         /*
1197          * Process new nvlist of vdevs.
1198          */
1199         for (i = 0; i < nl2cache; i++) {
1200                 VERIFY(nvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID,
1201                     &guid) == 0);
1202 
1203                 newvdevs[i] = NULL;
1204                 for (j = 0; j < oldnvdevs; j++) {
1205                         vd = oldvdevs[j];
1206                         if (vd != NULL && guid == vd->vdev_guid) {
1207                                 /*
1208                                  * Retain previous vdev for add/remove ops.
1209                                  */
1210                                 newvdevs[i] = vd;
1211                                 oldvdevs[j] = NULL;
1212                                 break;
1213                         }
1214                 }
1215 
1216                 if (newvdevs[i] == NULL) {
1217                         /*
1218                          * Create new vdev
1219                          */
1220                         VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
1221                             VDEV_ALLOC_L2CACHE) == 0);
1222                         ASSERT(vd != NULL);
1223                         newvdevs[i] = vd;
1224 
1225                         /*
1226                          * Commit this vdev as an l2cache device,
1227                          * even if it fails to open.
1228                          */
1229                         spa_l2cache_add(vd);
1230 
1231                         vd->vdev_top = vd;
1232                         vd->vdev_aux = sav;
1233 
1234                         spa_l2cache_activate(vd);
1235 
1236                         if (vdev_open(vd) != 0)
1237                                 continue;
1238 
1239                         (void) vdev_validate_aux(vd);
1240 
1241                         if (!vdev_is_dead(vd))
1242                                 l2arc_add_vdev(spa, vd);
1243                 }
1244         }
1245 
1246         /*
1247          * Purge vdevs that were dropped
1248          */
1249         for (i = 0; i < oldnvdevs; i++) {
1250                 uint64_t pool;
1251 
1252                 vd = oldvdevs[i];
1253                 if (vd != NULL) {
1254                         if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
1255                             pool != 0ULL && l2arc_vdev_present(vd))
1256                                 l2arc_remove_vdev(vd);
1257                         (void) vdev_close(vd);
1258                         spa_l2cache_remove(vd);
1259                 }
1260         }
1261 
1262         if (oldvdevs)
1263                 kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
1264 
1265         if (sav->sav_config == NULL)
1266                 goto out;
1267 
1268         sav->sav_vdevs = newvdevs;
1269         sav->sav_count = (int)nl2cache;
1270 
1271         /*
1272          * Recompute the stashed list of l2cache devices, with status
1273          * information this time.
1274          */
1275         VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
1276             DATA_TYPE_NVLIST_ARRAY) == 0);
1277 
1278         l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
1279         for (i = 0; i < sav->sav_count; i++)
1280                 l2cache[i] = vdev_config_generate(spa,
1281                     sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);
1282         VERIFY(nvlist_add_nvlist_array(sav->sav_config,
1283             ZPOOL_CONFIG_L2CACHE, l2cache, sav->sav_count) == 0);
1284 out:
1285         for (i = 0; i < sav->sav_count; i++)
1286                 nvlist_free(l2cache[i]);
1287         if (sav->sav_count)
1288                 kmem_free(l2cache, sav->sav_count * sizeof (void *));
1289 }
1290 
1291 static int
1292 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
1293 {
1294         dmu_buf_t *db;
1295         char *packed = NULL;
1296         size_t nvsize = 0;
1297         int error;
1298         *value = NULL;
1299 
1300         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
1301         nvsize = *(uint64_t *)db->db_data;
1302         dmu_buf_rele(db, FTAG);
1303 
1304         packed = kmem_alloc(nvsize, KM_SLEEP);
1305         error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
1306             DMU_READ_PREFETCH);
1307         if (error == 0)
1308                 error = nvlist_unpack(packed, nvsize, value, 0);
1309         kmem_free(packed, nvsize);
1310 
1311         return (error);
1312 }
1313 
1314 /*
1315  * Checks to see if the given vdev could not be opened, in which case we post a
1316  * sysevent to notify the autoreplace code that the device has been removed.
1317  */
1318 static void
1319 spa_check_removed(vdev_t *vd)
1320 {
1321         for (int c = 0; c < vd->vdev_children; c++)
1322                 spa_check_removed(vd->vdev_child[c]);
1323 
1324         if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd)) {
1325                 zfs_post_autoreplace(vd->vdev_spa, vd);
1326                 spa_event_notify(vd->vdev_spa, vd, ESC_ZFS_VDEV_CHECK);
1327         }
1328 }
1329 
1330 /*
1331  * Validate the current config against the MOS config
1332  */
1333 static boolean_t
1334 spa_config_valid(spa_t *spa, nvlist_t *config)
1335 {
1336         vdev_t *mrvd, *rvd = spa->spa_root_vdev;
1337         nvlist_t *nv;
1338 
1339         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nv) == 0);
1340 
1341         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1342         VERIFY(spa_config_parse(spa, &mrvd, nv, NULL, 0, VDEV_ALLOC_LOAD) == 0);
1343 
1344         ASSERT3U(rvd->vdev_children, ==, mrvd->vdev_children);
1345 
1346         /*
1347          * If we're doing a normal import, then build up any additional
1348          * diagnostic information about missing devices in this config.
1349          * We'll pass this up to the user for further processing.
1350          */
1351         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG)) {
1352                 nvlist_t **child, *nv;
1353                 uint64_t idx = 0;
1354 
1355                 child = kmem_alloc(rvd->vdev_children * sizeof (nvlist_t **),
1356                     KM_SLEEP);
1357                 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1358 
1359                 for (int c = 0; c < rvd->vdev_children; c++) {
1360                         vdev_t *tvd = rvd->vdev_child[c];
1361                         vdev_t *mtvd  = mrvd->vdev_child[c];
1362 
1363                         if (tvd->vdev_ops == &vdev_missing_ops &&
1364                             mtvd->vdev_ops != &vdev_missing_ops &&
1365                             mtvd->vdev_islog)
1366                                 child[idx++] = vdev_config_generate(spa, mtvd,
1367                                     B_FALSE, 0);
1368                 }
1369 
1370                 if (idx) {
1371                         VERIFY(nvlist_add_nvlist_array(nv,
1372                             ZPOOL_CONFIG_CHILDREN, child, idx) == 0);
1373                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
1374                             ZPOOL_CONFIG_MISSING_DEVICES, nv) == 0);
1375 
1376                         for (int i = 0; i < idx; i++)
1377                                 nvlist_free(child[i]);
1378                 }
1379                 nvlist_free(nv);
1380                 kmem_free(child, rvd->vdev_children * sizeof (char **));
1381         }
1382 
1383         /*
1384          * Compare the root vdev tree with the information we have
1385          * from the MOS config (mrvd). Check each top-level vdev
1386          * with the corresponding MOS config top-level (mtvd).
1387          */
1388         for (int c = 0; c < rvd->vdev_children; c++) {
1389                 vdev_t *tvd = rvd->vdev_child[c];
1390                 vdev_t *mtvd  = mrvd->vdev_child[c];
1391 
1392                 /*
1393                  * Resolve any "missing" vdevs in the current configuration.
1394                  * If we find that the MOS config has more accurate information
1395                  * about the top-level vdev then use that vdev instead.
1396                  */
1397                 if (tvd->vdev_ops == &vdev_missing_ops &&
1398                     mtvd->vdev_ops != &vdev_missing_ops) {
1399 
1400                         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG))
1401                                 continue;
1402 
1403                         /*
1404                          * Device specific actions.
1405                          */
1406                         if (mtvd->vdev_islog) {
1407                                 spa_set_log_state(spa, SPA_LOG_CLEAR);
1408                         } else {
1409                                 /*
1410                                  * XXX - once we have 'readonly' pool
1411                                  * support we should be able to handle
1412                                  * missing data devices by transitioning
1413                                  * the pool to readonly.
1414                                  */
1415                                 continue;
1416                         }
1417 
1418                         /*
1419                          * Swap the missing vdev with the data we were
1420                          * able to obtain from the MOS config.
1421                          */
1422                         vdev_remove_child(rvd, tvd);
1423                         vdev_remove_child(mrvd, mtvd);
1424 
1425                         vdev_add_child(rvd, mtvd);
1426                         vdev_add_child(mrvd, tvd);
1427 
1428                         spa_config_exit(spa, SCL_ALL, FTAG);
1429                         vdev_load(mtvd);
1430                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1431 
1432                         vdev_reopen(rvd);
1433                 } else if (mtvd->vdev_islog) {
1434                         /*
1435                          * Load the slog device's state from the MOS config
1436                          * since it's possible that the label does not
1437                          * contain the most up-to-date information.
1438                          */
1439                         vdev_load_log_state(tvd, mtvd);
1440                         vdev_reopen(tvd);
1441                 }
1442         }
1443         vdev_free(mrvd);
1444         spa_config_exit(spa, SCL_ALL, FTAG);
1445 
1446         /*
1447          * Ensure we were able to validate the config.
1448          */
1449         return (rvd->vdev_guid_sum == spa->spa_uberblock.ub_guid_sum);
1450 }
1451 
1452 /*
1453  * Check for missing log devices
1454  */
1455 static int
1456 spa_check_logs(spa_t *spa)
1457 {
1458         switch (spa->spa_log_state) {
1459         case SPA_LOG_MISSING:
1460                 /* need to recheck in case slog has been restored */
1461         case SPA_LOG_UNKNOWN:
1462                 if (dmu_objset_find(spa->spa_name, zil_check_log_chain, NULL,
1463                     DS_FIND_CHILDREN)) {
1464                         spa_set_log_state(spa, SPA_LOG_MISSING);
1465                         return (1);
1466                 }
1467                 break;
1468         }
1469         return (0);
1470 }
1471 
1472 static boolean_t
1473 spa_passivate_log(spa_t *spa)
1474 {
1475         vdev_t *rvd = spa->spa_root_vdev;
1476         boolean_t slog_found = B_FALSE;
1477 
1478         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1479 
1480         if (!spa_has_slogs(spa))
1481                 return (B_FALSE);
1482 
1483         for (int c = 0; c < rvd->vdev_children; c++) {
1484                 vdev_t *tvd = rvd->vdev_child[c];
1485                 metaslab_group_t *mg = tvd->vdev_mg;
1486 
1487                 if (tvd->vdev_islog) {
1488                         metaslab_group_passivate(mg);
1489                         slog_found = B_TRUE;
1490                 }
1491         }
1492 
1493         return (slog_found);
1494 }
1495 
1496 static void
1497 spa_activate_log(spa_t *spa)
1498 {
1499         vdev_t *rvd = spa->spa_root_vdev;
1500 
1501         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1502 
1503         for (int c = 0; c < rvd->vdev_children; c++) {
1504                 vdev_t *tvd = rvd->vdev_child[c];
1505                 metaslab_group_t *mg = tvd->vdev_mg;
1506 
1507                 if (tvd->vdev_islog)
1508                         metaslab_group_activate(mg);
1509         }
1510 }
1511 
1512 int
1513 spa_offline_log(spa_t *spa)
1514 {
1515         int error = 0;
1516 
1517         if ((error = dmu_objset_find(spa_name(spa), zil_vdev_offline,
1518             NULL, DS_FIND_CHILDREN)) == 0) {
1519 
1520                 /*
1521                  * We successfully offlined the log device, sync out the
1522                  * current txg so that the "stubby" block can be removed
1523                  * by zil_sync().
1524                  */
1525                 txg_wait_synced(spa->spa_dsl_pool, 0);
1526         }
1527         return (error);
1528 }
1529 
1530 static void
1531 spa_aux_check_removed(spa_aux_vdev_t *sav)
1532 {
1533         for (int i = 0; i < sav->sav_count; i++)
1534                 spa_check_removed(sav->sav_vdevs[i]);
1535 }
1536 
1537 void
1538 spa_claim_notify(zio_t *zio)
1539 {
1540         spa_t *spa = zio->io_spa;
1541 
1542         if (zio->io_error)
1543                 return;
1544 
1545         mutex_enter(&spa->spa_props_lock);       /* any mutex will do */
1546         if (spa->spa_claim_max_txg < zio->io_bp->blk_birth)
1547                 spa->spa_claim_max_txg = zio->io_bp->blk_birth;
1548         mutex_exit(&spa->spa_props_lock);
1549 }
1550 
1551 typedef struct spa_load_error {
1552         uint64_t        sle_meta_count;
1553         uint64_t        sle_data_count;
1554 } spa_load_error_t;
1555 
1556 static void
1557 spa_load_verify_done(zio_t *zio)
1558 {
1559         blkptr_t *bp = zio->io_bp;
1560         spa_load_error_t *sle = zio->io_private;
1561         dmu_object_type_t type = BP_GET_TYPE(bp);
1562         int error = zio->io_error;
1563 
1564         if (error) {
1565                 if ((BP_GET_LEVEL(bp) != 0 || dmu_ot[type].ot_metadata) &&
1566                     type != DMU_OT_INTENT_LOG)
1567                         atomic_add_64(&sle->sle_meta_count, 1);
1568                 else
1569                         atomic_add_64(&sle->sle_data_count, 1);
1570         }
1571         zio_data_buf_free(zio->io_data, zio->io_size);
1572 }
1573 
1574 /*ARGSUSED*/
1575 static int
1576 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1577     arc_buf_t *pbuf, const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1578 {
1579         if (bp != NULL) {
1580                 zio_t *rio = arg;
1581                 size_t size = BP_GET_PSIZE(bp);
1582                 void *data = zio_data_buf_alloc(size);
1583 
1584                 zio_nowait(zio_read(rio, spa, bp, data, size,
1585                     spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
1586                     ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
1587                     ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
1588         }
1589         return (0);
1590 }
1591 
1592 static int
1593 spa_load_verify(spa_t *spa)
1594 {
1595         zio_t *rio;
1596         spa_load_error_t sle = { 0 };
1597         zpool_rewind_policy_t policy;
1598         boolean_t verify_ok = B_FALSE;
1599         int error;
1600 
1601         zpool_get_rewind_policy(spa->spa_config, &policy);
1602 
1603         if (policy.zrp_request & ZPOOL_NEVER_REWIND)
1604                 return (0);
1605 
1606         rio = zio_root(spa, NULL, &sle,
1607             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1608 
1609         error = traverse_pool(spa, spa->spa_verify_min_txg,
1610             TRAVERSE_PRE | TRAVERSE_PREFETCH, spa_load_verify_cb, rio);
1611 
1612         (void) zio_wait(rio);
1613 
1614         spa->spa_load_meta_errors = sle.sle_meta_count;
1615         spa->spa_load_data_errors = sle.sle_data_count;
1616 
1617         if (!error && sle.sle_meta_count <= policy.zrp_maxmeta &&
1618             sle.sle_data_count <= policy.zrp_maxdata) {
1619                 int64_t loss = 0;
1620 
1621                 verify_ok = B_TRUE;
1622                 spa->spa_load_txg = spa->spa_uberblock.ub_txg;
1623                 spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
1624 
1625                 loss = spa->spa_last_ubsync_txg_ts - spa->spa_load_txg_ts;
1626                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1627                     ZPOOL_CONFIG_LOAD_TIME, spa->spa_load_txg_ts) == 0);
1628                 VERIFY(nvlist_add_int64(spa->spa_load_info,
1629                     ZPOOL_CONFIG_REWIND_TIME, loss) == 0);
1630                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1631                     ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count) == 0);
1632         } else {
1633                 spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
1634         }
1635 
1636         if (error) {
1637                 if (error != ENXIO && error != EIO)
1638                         error = EIO;
1639                 return (error);
1640         }
1641 
1642         return (verify_ok ? 0 : EIO);
1643 }
1644 
1645 /*
1646  * Find a value in the pool props object.
1647  */
1648 static void
1649 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
1650 {
1651         (void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
1652             zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
1653 }
1654 
1655 /*
1656  * Find a value in the pool directory object.
1657  */
1658 static int
1659 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val)
1660 {
1661         return (zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1662             name, sizeof (uint64_t), 1, val));
1663 }
1664 
1665 static int
1666 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
1667 {
1668         vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
1669         return (err);
1670 }
1671 
1672 /*
1673  * Fix up config after a partly-completed split.  This is done with the
1674  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
1675  * pool have that entry in their config, but only the splitting one contains
1676  * a list of all the guids of the vdevs that are being split off.
1677  *
1678  * This function determines what to do with that list: either rejoin
1679  * all the disks to the pool, or complete the splitting process.  To attempt
1680  * the rejoin, each disk that is offlined is marked online again, and
1681  * we do a reopen() call.  If the vdev label for every disk that was
1682  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
1683  * then we call vdev_split() on each disk, and complete the split.
1684  *
1685  * Otherwise we leave the config alone, with all the vdevs in place in
1686  * the original pool.
1687  */
1688 static void
1689 spa_try_repair(spa_t *spa, nvlist_t *config)
1690 {
1691         uint_t extracted;
1692         uint64_t *glist;
1693         uint_t i, gcount;
1694         nvlist_t *nvl;
1695         vdev_t **vd;
1696         boolean_t attempt_reopen;
1697 
1698         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
1699                 return;
1700 
1701         /* check that the config is complete */
1702         if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
1703             &glist, &gcount) != 0)
1704                 return;
1705 
1706         vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
1707 
1708         /* attempt to online all the vdevs & validate */
1709         attempt_reopen = B_TRUE;
1710         for (i = 0; i < gcount; i++) {
1711                 if (glist[i] == 0)      /* vdev is hole */
1712                         continue;
1713 
1714                 vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
1715                 if (vd[i] == NULL) {
1716                         /*
1717                          * Don't bother attempting to reopen the disks;
1718                          * just do the split.
1719                          */
1720                         attempt_reopen = B_FALSE;
1721                 } else {
1722                         /* attempt to re-online it */
1723                         vd[i]->vdev_offline = B_FALSE;
1724                 }
1725         }
1726 
1727         if (attempt_reopen) {
1728                 vdev_reopen(spa->spa_root_vdev);
1729 
1730                 /* check each device to see what state it's in */
1731                 for (extracted = 0, i = 0; i < gcount; i++) {
1732                         if (vd[i] != NULL &&
1733                             vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
1734                                 break;
1735                         ++extracted;
1736                 }
1737         }
1738 
1739         /*
1740          * If every disk has been moved to the new pool, or if we never
1741          * even attempted to look at them, then we split them off for
1742          * good.
1743          */
1744         if (!attempt_reopen || gcount == extracted) {
1745                 for (i = 0; i < gcount; i++)
1746                         if (vd[i] != NULL)
1747                                 vdev_split(vd[i]);
1748                 vdev_reopen(spa->spa_root_vdev);
1749         }
1750 
1751         kmem_free(vd, gcount * sizeof (vdev_t *));
1752 }
1753 
1754 static int
1755 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
1756     boolean_t mosconfig)
1757 {
1758         nvlist_t *config = spa->spa_config;
1759         char *ereport = FM_EREPORT_ZFS_POOL;
1760         int error;
1761         uint64_t pool_guid;
1762         nvlist_t *nvl;
1763 
1764         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
1765                 return (EINVAL);
1766 
1767         /*
1768          * Versioning wasn't explicitly added to the label until later, so if
1769          * it's not present treat it as the initial version.
1770          */
1771         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
1772             &spa->spa_ubsync.ub_version) != 0)
1773                 spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
1774 
1775         (void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
1776             &spa->spa_config_txg);
1777 
1778         if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
1779             spa_guid_exists(pool_guid, 0)) {
1780                 error = EEXIST;
1781         } else {
1782                 spa->spa_config_guid = pool_guid;
1783 
1784                 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT,
1785                     &nvl) == 0) {
1786                         VERIFY(nvlist_dup(nvl, &spa->spa_config_splitting,
1787                             KM_SLEEP) == 0);
1788                 }
1789 
1790                 gethrestime(&spa->spa_loaded_ts);
1791                 error = spa_load_impl(spa, pool_guid, config, state, type,
1792                     mosconfig, &ereport);
1793         }
1794 
1795         spa->spa_minref = refcount_count(&spa->spa_refcount);
1796         if (error) {
1797                 if (error != EEXIST) {
1798                         spa->spa_loaded_ts.tv_sec = 0;
1799                         spa->spa_loaded_ts.tv_nsec = 0;
1800                 }
1801                 if (error != EBADF) {
1802                         zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
1803                 }
1804         }
1805         spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
1806         spa->spa_ena = 0;
1807 
1808         return (error);
1809 }
1810 
1811 /*
1812  * Load an existing storage pool, using the pool's builtin spa_config as a
1813  * source of configuration information.
1814  */
1815 static int
1816 spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config,
1817     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
1818     char **ereport)
1819 {
1820         int error = 0;
1821         nvlist_t *nvroot = NULL;
1822         vdev_t *rvd;
1823         uberblock_t *ub = &spa->spa_uberblock;
1824         uint64_t children, config_cache_txg = spa->spa_config_txg;
1825         int orig_mode = spa->spa_mode;
1826         int parse;
1827         uint64_t obj;
1828 
1829         /*
1830          * If this is an untrusted config, access the pool in read-only mode.
1831          * This prevents things like resilvering recently removed devices.
1832          */
1833         if (!mosconfig)
1834                 spa->spa_mode = FREAD;
1835 
1836         ASSERT(MUTEX_HELD(&spa_namespace_lock));
1837 
1838         spa->spa_load_state = state;
1839 
1840         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot))
1841                 return (EINVAL);
1842 
1843         parse = (type == SPA_IMPORT_EXISTING ?
1844             VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
1845 
1846         /*
1847          * Create "The Godfather" zio to hold all async IOs
1848          */
1849         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
1850             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
1851 
1852         /*
1853          * Parse the configuration into a vdev tree.  We explicitly set the
1854          * value that will be returned by spa_version() since parsing the
1855          * configuration requires knowing the version number.
1856          */
1857         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1858         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, parse);
1859         spa_config_exit(spa, SCL_ALL, FTAG);
1860 
1861         if (error != 0)
1862                 return (error);
1863 
1864         ASSERT(spa->spa_root_vdev == rvd);
1865 
1866         if (type != SPA_IMPORT_ASSEMBLE) {
1867                 ASSERT(spa_guid(spa) == pool_guid);
1868         }
1869 
1870         /*
1871          * Try to open all vdevs, loading each label in the process.
1872          */
1873         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1874         error = vdev_open(rvd);
1875         spa_config_exit(spa, SCL_ALL, FTAG);
1876         if (error != 0)
1877                 return (error);
1878 
1879         /*
1880          * We need to validate the vdev labels against the configuration that
1881          * we have in hand, which is dependent on the setting of mosconfig. If
1882          * mosconfig is true then we're validating the vdev labels based on
1883          * that config.  Otherwise, we're validating against the cached config
1884          * (zpool.cache) that was read when we loaded the zfs module, and then
1885          * later we will recursively call spa_load() and validate against
1886          * the vdev config.
1887          *
1888          * If we're assembling a new pool that's been split off from an
1889          * existing pool, the labels haven't yet been updated so we skip
1890          * validation for now.
1891          */
1892         if (type != SPA_IMPORT_ASSEMBLE) {
1893                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1894                 error = vdev_validate(rvd);
1895                 spa_config_exit(spa, SCL_ALL, FTAG);
1896 
1897                 if (error != 0)
1898                         return (error);
1899 
1900                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
1901                         return (ENXIO);
1902         }
1903 
1904         /*
1905          * Find the best uberblock.
1906          */
1907         vdev_uberblock_load(NULL, rvd, ub);
1908 
1909         /*
1910          * If we weren't able to find a single valid uberblock, return failure.
1911          */
1912         if (ub->ub_txg == 0)
1913                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
1914 
1915         /*
1916          * If the pool is newer than the code, we can't open it.
1917          */
1918         if (ub->ub_version > SPA_VERSION)
1919                 return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
1920 
1921         /*
1922          * If the vdev guid sum doesn't match the uberblock, we have an
1923          * incomplete configuration.  We first check to see if the pool
1924          * is aware of the complete config (i.e ZPOOL_CONFIG_VDEV_CHILDREN).
1925          * If it is, defer the vdev_guid_sum check till later so we
1926          * can handle missing vdevs.
1927          */
1928         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN,
1929             &children) != 0 && mosconfig && type != SPA_IMPORT_ASSEMBLE &&
1930             rvd->vdev_guid_sum != ub->ub_guid_sum)
1931                 return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
1932 
1933         if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
1934                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1935                 spa_try_repair(spa, config);
1936                 spa_config_exit(spa, SCL_ALL, FTAG);
1937                 nvlist_free(spa->spa_config_splitting);
1938                 spa->spa_config_splitting = NULL;
1939         }
1940 
1941         /*
1942          * Initialize internal SPA structures.
1943          */
1944         spa->spa_state = POOL_STATE_ACTIVE;
1945         spa->spa_ubsync = spa->spa_uberblock;
1946         spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
1947             TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
1948         spa->spa_first_txg = spa->spa_last_ubsync_txg ?
1949             spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
1950         spa->spa_claim_max_txg = spa->spa_first_txg;
1951         spa->spa_prev_software_version = ub->ub_software_version;
1952 
1953         error = dsl_pool_open(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
1954         if (error)
1955                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1956         spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
1957 
1958         if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object) != 0)
1959                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1960 
1961         if (!mosconfig) {
1962                 uint64_t hostid;
1963                 nvlist_t *policy = NULL, *nvconfig;
1964 
1965                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
1966                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1967 
1968                 if (!spa_is_root(spa) && nvlist_lookup_uint64(nvconfig,
1969                     ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
1970                         char *hostname;
1971                         unsigned long myhostid = 0;
1972 
1973                         VERIFY(nvlist_lookup_string(nvconfig,
1974                             ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
1975 
1976 #ifdef  _KERNEL
1977                         myhostid = zone_get_hostid(NULL);
1978 #else   /* _KERNEL */
1979                         /*
1980                          * We're emulating the system's hostid in userland, so
1981                          * we can't use zone_get_hostid().
1982                          */
1983                         (void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
1984 #endif  /* _KERNEL */
1985                         if (hostid != 0 && myhostid != 0 &&
1986                             hostid != myhostid) {
1987                                 nvlist_free(nvconfig);
1988                                 cmn_err(CE_WARN, "pool '%s' could not be "
1989                                     "loaded as it was last accessed by "
1990                                     "another system (host: %s hostid: 0x%lx). "
1991                                     "See: http://www.sun.com/msg/ZFS-8000-EY",
1992                                     spa_name(spa), hostname,
1993                                     (unsigned long)hostid);
1994                                 return (EBADF);
1995                         }
1996                 }
1997                 if (nvlist_lookup_nvlist(spa->spa_config,
1998                     ZPOOL_REWIND_POLICY, &policy) == 0)
1999                         VERIFY(nvlist_add_nvlist(nvconfig,
2000                             ZPOOL_REWIND_POLICY, policy) == 0);
2001 
2002                 spa_config_set(spa, nvconfig);
2003                 spa_unload(spa);
2004                 spa_deactivate(spa);
2005                 spa_activate(spa, orig_mode);
2006 
2007                 return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
2008         }
2009 
2010         if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj) != 0)
2011                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2012         error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
2013         if (error != 0)
2014                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2015 
2016         /*
2017          * Load the bit that tells us to use the new accounting function
2018          * (raid-z deflation).  If we have an older pool, this will not
2019          * be present.
2020          */
2021         error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate);
2022         if (error != 0 && error != ENOENT)
2023                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2024 
2025         error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
2026             &spa->spa_creation_version);
2027         if (error != 0 && error != ENOENT)
2028                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2029 
2030         /*
2031          * Load the persistent error log.  If we have an older pool, this will
2032          * not be present.
2033          */
2034         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last);
2035         if (error != 0 && error != ENOENT)
2036                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2037 
2038         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
2039             &spa->spa_errlog_scrub);
2040         if (error != 0 && error != ENOENT)
2041                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2042 
2043         /*
2044          * Load the history object.  If we have an older pool, this
2045          * will not be present.
2046          */
2047         error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history);
2048         if (error != 0 && error != ENOENT)
2049                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2050 
2051         /*
2052          * If we're assembling the pool from the split-off vdevs of
2053          * an existing pool, we don't want to attach the spares & cache
2054          * devices.
2055          */
2056 
2057         /*
2058          * Load any hot spares for this pool.
2059          */
2060         error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object);
2061         if (error != 0 && error != ENOENT)
2062                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2063         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2064                 ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
2065                 if (load_nvlist(spa, spa->spa_spares.sav_object,
2066                     &spa->spa_spares.sav_config) != 0)
2067                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2068 
2069                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2070                 spa_load_spares(spa);
2071                 spa_config_exit(spa, SCL_ALL, FTAG);
2072         } else if (error == 0) {
2073                 spa->spa_spares.sav_sync = B_TRUE;
2074         }
2075 
2076         /*
2077          * Load any level 2 ARC devices for this pool.
2078          */
2079         error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
2080             &spa->spa_l2cache.sav_object);
2081         if (error != 0 && error != ENOENT)
2082                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2083         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2084                 ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
2085                 if (load_nvlist(spa, spa->spa_l2cache.sav_object,
2086                     &spa->spa_l2cache.sav_config) != 0)
2087                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2088 
2089                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2090                 spa_load_l2cache(spa);
2091                 spa_config_exit(spa, SCL_ALL, FTAG);
2092         } else if (error == 0) {
2093                 spa->spa_l2cache.sav_sync = B_TRUE;
2094         }
2095 
2096         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2097 
2098         error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object);
2099         if (error && error != ENOENT)
2100                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2101 
2102         if (error == 0) {
2103                 uint64_t autoreplace;
2104 
2105                 spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
2106                 spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
2107                 spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
2108                 spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
2109                 spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
2110                 spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
2111                     &spa->spa_dedup_ditto);
2112 
2113                 spa->spa_autoreplace = (autoreplace != 0);
2114         }
2115 
2116         /*
2117          * If the 'autoreplace' property is set, then post a resource notifying
2118          * the ZFS DE that it should not issue any faults for unopenable
2119          * devices.  We also iterate over the vdevs, and post a sysevent for any
2120          * unopenable vdevs so that the normal autoreplace handler can take
2121          * over.
2122          */
2123         if (spa->spa_autoreplace && state != SPA_LOAD_TRYIMPORT) {
2124                 spa_check_removed(spa->spa_root_vdev);
2125                 /*
2126                  * For the import case, this is done in spa_import(), because
2127                  * at this point we're using the spare definitions from
2128                  * the MOS config, not necessarily from the userland config.
2129                  */
2130                 if (state != SPA_LOAD_IMPORT) {
2131                         spa_aux_check_removed(&spa->spa_spares);
2132                         spa_aux_check_removed(&spa->spa_l2cache);
2133                 }
2134         }
2135 
2136         /*
2137          * Load the vdev state for all toplevel vdevs.
2138          */
2139         vdev_load(rvd);
2140 
2141         /*
2142          * Propagate the leaf DTLs we just loaded all the way up the tree.
2143          */
2144         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2145         vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
2146         spa_config_exit(spa, SCL_ALL, FTAG);
2147 
2148         /*
2149          * Load the DDTs (dedup tables).
2150          */
2151         error = ddt_load(spa);
2152         if (error != 0)
2153                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2154 
2155         spa_update_dspace(spa);
2156 
2157         /*
2158          * Validate the config, using the MOS config to fill in any
2159          * information which might be missing.  If we fail to validate
2160          * the config then declare the pool unfit for use. If we're
2161          * assembling a pool from a split, the log is not transferred
2162          * over.
2163          */
2164         if (type != SPA_IMPORT_ASSEMBLE) {
2165                 nvlist_t *nvconfig;
2166 
2167                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2168                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2169 
2170                 if (!spa_config_valid(spa, nvconfig)) {
2171                         nvlist_free(nvconfig);
2172                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
2173                             ENXIO));
2174                 }
2175                 nvlist_free(nvconfig);
2176 
2177                 /*
2178                  * Now that we've validate the config, check the state of the
2179                  * root vdev.  If it can't be opened, it indicates one or
2180                  * more toplevel vdevs are faulted.
2181                  */
2182                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2183                         return (ENXIO);
2184 
2185                 if (spa_check_logs(spa)) {
2186                         *ereport = FM_EREPORT_ZFS_LOG_REPLAY;
2187                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG, ENXIO));
2188                 }
2189         }
2190 
2191         /*
2192          * We've successfully opened the pool, verify that we're ready
2193          * to start pushing transactions.
2194          */
2195         if (state != SPA_LOAD_TRYIMPORT) {
2196                 if (error = spa_load_verify(spa))
2197                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2198                             error));
2199         }
2200 
2201         if (spa_writeable(spa) && (state == SPA_LOAD_RECOVER ||
2202             spa->spa_load_max_txg == UINT64_MAX)) {
2203                 dmu_tx_t *tx;
2204                 int need_update = B_FALSE;
2205 
2206                 ASSERT(state != SPA_LOAD_TRYIMPORT);
2207 
2208                 /*
2209                  * Claim log blocks that haven't been committed yet.
2210                  * This must all happen in a single txg.
2211                  * Note: spa_claim_max_txg is updated by spa_claim_notify(),
2212                  * invoked from zil_claim_log_block()'s i/o done callback.
2213                  * Price of rollback is that we abandon the log.
2214                  */
2215                 spa->spa_claiming = B_TRUE;
2216 
2217                 tx = dmu_tx_create_assigned(spa_get_dsl(spa),
2218                     spa_first_txg(spa));
2219                 (void) dmu_objset_find(spa_name(spa),
2220                     zil_claim, tx, DS_FIND_CHILDREN);
2221                 dmu_tx_commit(tx);
2222 
2223                 spa->spa_claiming = B_FALSE;
2224 
2225                 spa_set_log_state(spa, SPA_LOG_GOOD);
2226                 spa->spa_sync_on = B_TRUE;
2227                 txg_sync_start(spa->spa_dsl_pool);
2228 
2229                 /*
2230                  * Wait for all claims to sync.  We sync up to the highest
2231                  * claimed log block birth time so that claimed log blocks
2232                  * don't appear to be from the future.  spa_claim_max_txg
2233                  * will have been set for us by either zil_check_log_chain()
2234                  * (invoked from spa_check_logs()) or zil_claim() above.
2235                  */
2236                 txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
2237 
2238                 /*
2239                  * If the config cache is stale, or we have uninitialized
2240                  * metaslabs (see spa_vdev_add()), then update the config.
2241                  *
2242                  * If this is a verbatim import, trust the current
2243                  * in-core spa_config and update the disk labels.
2244                  */
2245                 if (config_cache_txg != spa->spa_config_txg ||
2246                     state == SPA_LOAD_IMPORT ||
2247                     state == SPA_LOAD_RECOVER ||
2248                     (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
2249                         need_update = B_TRUE;
2250 
2251                 for (int c = 0; c < rvd->vdev_children; c++)
2252                         if (rvd->vdev_child[c]->vdev_ms_array == 0)
2253                                 need_update = B_TRUE;
2254 
2255                 /*
2256                  * Update the config cache asychronously in case we're the
2257                  * root pool, in which case the config cache isn't writable yet.
2258                  */
2259                 if (need_update)
2260                         spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2261 
2262                 /*
2263                  * Check all DTLs to see if anything needs resilvering.
2264                  */
2265                 if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
2266                     vdev_resilver_needed(rvd, NULL, NULL))
2267                         spa_async_request(spa, SPA_ASYNC_RESILVER);
2268 
2269                 /*
2270                  * Delete any inconsistent datasets.
2271                  */
2272                 (void) dmu_objset_find(spa_name(spa),
2273                     dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
2274 
2275                 /*
2276                  * Clean up any stale temporary dataset userrefs.
2277                  */
2278                 dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
2279         }
2280 
2281         return (0);
2282 }
2283 
2284 static int
2285 spa_load_retry(spa_t *spa, spa_load_state_t state, int mosconfig)
2286 {
2287         int mode = spa->spa_mode;
2288 
2289         spa_unload(spa);
2290         spa_deactivate(spa);
2291 
2292         spa->spa_load_max_txg--;
2293 
2294         spa_activate(spa, mode);
2295         spa_async_suspend(spa);
2296 
2297         return (spa_load(spa, state, SPA_IMPORT_EXISTING, mosconfig));
2298 }
2299 
2300 static int
2301 spa_load_best(spa_t *spa, spa_load_state_t state, int mosconfig,
2302     uint64_t max_request, int rewind_flags)
2303 {
2304         nvlist_t *config = NULL;
2305         int load_error, rewind_error;
2306         uint64_t safe_rewind_txg;
2307         uint64_t min_txg;
2308 
2309         if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
2310                 spa->spa_load_max_txg = spa->spa_load_txg;
2311                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2312         } else {
2313                 spa->spa_load_max_txg = max_request;
2314         }
2315 
2316         load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING,
2317             mosconfig);
2318         if (load_error == 0)
2319                 return (0);
2320 
2321         if (spa->spa_root_vdev != NULL)
2322                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2323 
2324         spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
2325         spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
2326 
2327         if (rewind_flags & ZPOOL_NEVER_REWIND) {
2328                 nvlist_free(config);
2329                 return (load_error);
2330         }
2331 
2332         /* Price of rolling back is discarding txgs, including log */
2333         if (state == SPA_LOAD_RECOVER)
2334                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2335 
2336         spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
2337         safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
2338         min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
2339             TXG_INITIAL : safe_rewind_txg;
2340 
2341         /*
2342          * Continue as long as we're finding errors, we're still within
2343          * the acceptable rewind range, and we're still finding uberblocks
2344          */
2345         while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
2346             spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
2347                 if (spa->spa_load_max_txg < safe_rewind_txg)
2348                         spa->spa_extreme_rewind = B_TRUE;
2349                 rewind_error = spa_load_retry(spa, state, mosconfig);
2350         }
2351 
2352         spa->spa_extreme_rewind = B_FALSE;
2353         spa->spa_load_max_txg = UINT64_MAX;
2354 
2355         if (config && (rewind_error || state != SPA_LOAD_RECOVER))
2356                 spa_config_set(spa, config);
2357 
2358         return (state == SPA_LOAD_RECOVER ? rewind_error : load_error);
2359 }
2360 
2361 /*
2362  * Pool Open/Import
2363  *
2364  * The import case is identical to an open except that the configuration is sent
2365  * down from userland, instead of grabbed from the configuration cache.  For the
2366  * case of an open, the pool configuration will exist in the
2367  * POOL_STATE_UNINITIALIZED state.
2368  *
2369  * The stats information (gen/count/ustats) is used to gather vdev statistics at
2370  * the same time open the pool, without having to keep around the spa_t in some
2371  * ambiguous state.
2372  */
2373 static int
2374 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
2375     nvlist_t **config)
2376 {
2377         spa_t *spa;
2378         spa_load_state_t state = SPA_LOAD_OPEN;
2379         int error;
2380         int locked = B_FALSE;
2381 
2382         *spapp = NULL;
2383 
2384         /*
2385          * As disgusting as this is, we need to support recursive calls to this
2386          * function because dsl_dir_open() is called during spa_load(), and ends
2387          * up calling spa_open() again.  The real fix is to figure out how to
2388          * avoid dsl_dir_open() calling this in the first place.
2389          */
2390         if (mutex_owner(&spa_namespace_lock) != curthread) {
2391                 mutex_enter(&spa_namespace_lock);
2392                 locked = B_TRUE;
2393         }
2394 
2395         if ((spa = spa_lookup(pool)) == NULL) {
2396                 if (locked)
2397                         mutex_exit(&spa_namespace_lock);
2398                 return (ENOENT);
2399         }
2400 
2401         if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
2402                 zpool_rewind_policy_t policy;
2403 
2404                 zpool_get_rewind_policy(nvpolicy ? nvpolicy : spa->spa_config,
2405                     &policy);
2406                 if (policy.zrp_request & ZPOOL_DO_REWIND)
2407                         state = SPA_LOAD_RECOVER;
2408 
2409                 spa_activate(spa, spa_mode_global);
2410 
2411                 if (state != SPA_LOAD_RECOVER)
2412                         spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
2413 
2414                 error = spa_load_best(spa, state, B_FALSE, policy.zrp_txg,
2415                     policy.zrp_request);
2416 
2417                 if (error == EBADF) {
2418                         /*
2419                          * If vdev_validate() returns failure (indicated by
2420                          * EBADF), it indicates that one of the vdevs indicates
2421                          * that the pool has been exported or destroyed.  If
2422                          * this is the case, the config cache is out of sync and
2423                          * we should remove the pool from the namespace.
2424                          */
2425                         spa_unload(spa);
2426                         spa_deactivate(spa);
2427                         spa_config_sync(spa, B_TRUE, B_TRUE);
2428                         spa_remove(spa);
2429                         if (locked)
2430                                 mutex_exit(&spa_namespace_lock);
2431                         return (ENOENT);
2432                 }
2433 
2434                 if (error) {
2435                         /*
2436                          * We can't open the pool, but we still have useful
2437                          * information: the state of each vdev after the
2438                          * attempted vdev_open().  Return this to the user.
2439                          */
2440                         if (config != NULL && spa->spa_config) {
2441                                 VERIFY(nvlist_dup(spa->spa_config, config,
2442                                     KM_SLEEP) == 0);
2443                                 VERIFY(nvlist_add_nvlist(*config,
2444                                     ZPOOL_CONFIG_LOAD_INFO,
2445                                     spa->spa_load_info) == 0);
2446                         }
2447                         spa_unload(spa);
2448                         spa_deactivate(spa);
2449                         spa->spa_last_open_failed = error;
2450                         if (locked)
2451                                 mutex_exit(&spa_namespace_lock);
2452                         *spapp = NULL;
2453                         return (error);
2454                 }
2455         }
2456 
2457         spa_open_ref(spa, tag);
2458 
2459         if (config != NULL)
2460                 *config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2461 
2462         /*
2463          * If we've recovered the pool, pass back any information we
2464          * gathered while doing the load.
2465          */
2466         if (state == SPA_LOAD_RECOVER) {
2467                 VERIFY(nvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
2468                     spa->spa_load_info) == 0);
2469         }
2470 
2471         if (locked) {
2472                 spa->spa_last_open_failed = 0;
2473                 spa->spa_last_ubsync_txg = 0;
2474                 spa->spa_load_txg = 0;
2475                 mutex_exit(&spa_namespace_lock);
2476         }
2477 
2478         *spapp = spa;
2479 
2480         return (0);
2481 }
2482 
2483 int
2484 spa_open_rewind(const char *name, spa_t **spapp, void *tag, nvlist_t *policy,
2485     nvlist_t **config)
2486 {
2487         return (spa_open_common(name, spapp, tag, policy, config));
2488 }
2489 
2490 int
2491 spa_open(const char *name, spa_t **spapp, void *tag)
2492 {
2493         return (spa_open_common(name, spapp, tag, NULL, NULL));
2494 }
2495 
2496 /*
2497  * Lookup the given spa_t, incrementing the inject count in the process,
2498  * preventing it from being exported or destroyed.
2499  */
2500 spa_t *
2501 spa_inject_addref(char *name)
2502 {
2503         spa_t *spa;
2504 
2505         mutex_enter(&spa_namespace_lock);
2506         if ((spa = spa_lookup(name)) == NULL) {
2507                 mutex_exit(&spa_namespace_lock);
2508                 return (NULL);
2509         }
2510         spa->spa_inject_ref++;
2511         mutex_exit(&spa_namespace_lock);
2512 
2513         return (spa);
2514 }
2515 
2516 void
2517 spa_inject_delref(spa_t *spa)
2518 {
2519         mutex_enter(&spa_namespace_lock);
2520         spa->spa_inject_ref--;
2521         mutex_exit(&spa_namespace_lock);
2522 }
2523 
2524 /*
2525  * Add spares device information to the nvlist.
2526  */
2527 static void
2528 spa_add_spares(spa_t *spa, nvlist_t *config)
2529 {
2530         nvlist_t **spares;
2531         uint_t i, nspares;
2532         nvlist_t *nvroot;
2533         uint64_t guid;
2534         vdev_stat_t *vs;
2535         uint_t vsc;
2536         uint64_t pool;
2537 
2538         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
2539 
2540         if (spa->spa_spares.sav_count == 0)
2541                 return;
2542 
2543         VERIFY(nvlist_lookup_nvlist(config,
2544             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
2545         VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
2546             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
2547         if (nspares != 0) {
2548                 VERIFY(nvlist_add_nvlist_array(nvroot,
2549                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
2550                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
2551                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
2552 
2553                 /*
2554                  * Go through and find any spares which have since been
2555                  * repurposed as an active spare.  If this is the case, update
2556                  * their status appropriately.
2557                  */
2558                 for (i = 0; i < nspares; i++) {
2559                         VERIFY(nvlist_lookup_uint64(spares[i],
2560                             ZPOOL_CONFIG_GUID, &guid) == 0);
2561                         if (spa_spare_exists(guid, &pool, NULL) &&
2562                             pool != 0ULL) {
2563                                 VERIFY(nvlist_lookup_uint64_array(
2564                                     spares[i], ZPOOL_CONFIG_VDEV_STATS,
2565                                     (uint64_t **)&vs, &vsc) == 0);
2566                                 vs->vs_state = VDEV_STATE_CANT_OPEN;
2567                                 vs->vs_aux = VDEV_AUX_SPARED;
2568                         }
2569                 }
2570         }
2571 }
2572 
2573 /*
2574  * Add l2cache device information to the nvlist, including vdev stats.
2575  */
2576 static void
2577 spa_add_l2cache(spa_t *spa, nvlist_t *config)
2578 {
2579         nvlist_t **l2cache;
2580         uint_t i, j, nl2cache;
2581         nvlist_t *nvroot;
2582         uint64_t guid;
2583         vdev_t *vd;
2584         vdev_stat_t *vs;
2585         uint_t vsc;
2586 
2587         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
2588 
2589         if (spa->spa_l2cache.sav_count == 0)
2590                 return;
2591 
2592         VERIFY(nvlist_lookup_nvlist(config,
2593             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
2594         VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
2595             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
2596         if (nl2cache != 0) {
2597                 VERIFY(nvlist_add_nvlist_array(nvroot,
2598                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
2599                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
2600                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
2601 
2602                 /*
2603                  * Update level 2 cache device stats.
2604                  */
2605 
2606                 for (i = 0; i < nl2cache; i++) {
2607                         VERIFY(nvlist_lookup_uint64(l2cache[i],
2608                             ZPOOL_CONFIG_GUID, &guid) == 0);
2609 
2610                         vd = NULL;
2611                         for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
2612                                 if (guid ==
2613                                     spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
2614                                         vd = spa->spa_l2cache.sav_vdevs[j];
2615                                         break;
2616                                 }
2617                         }
2618                         ASSERT(vd != NULL);
2619 
2620                         VERIFY(nvlist_lookup_uint64_array(l2cache[i],
2621                             ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc)
2622                             == 0);
2623                         vdev_get_stats(vd, vs);
2624                 }
2625         }
2626 }
2627 
2628 int
2629 spa_get_stats(const char *name, nvlist_t **config, char *altroot, size_t buflen)
2630 {
2631         int error;
2632         spa_t *spa;
2633 
2634         *config = NULL;
2635         error = spa_open_common(name, &spa, FTAG, NULL, config);
2636 
2637         if (spa != NULL) {
2638                 /*
2639                  * This still leaves a window of inconsistency where the spares
2640                  * or l2cache devices could change and the config would be
2641                  * self-inconsistent.
2642                  */
2643                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
2644 
2645                 if (*config != NULL) {
2646                         uint64_t loadtimes[2];
2647 
2648                         loadtimes[0] = spa->spa_loaded_ts.tv_sec;
2649                         loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
2650                         VERIFY(nvlist_add_uint64_array(*config,
2651                             ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2) == 0);
2652 
2653                         VERIFY(nvlist_add_uint64(*config,
2654                             ZPOOL_CONFIG_ERRCOUNT,
2655                             spa_get_errlog_size(spa)) == 0);
2656 
2657                         if (spa_suspended(spa))
2658                                 VERIFY(nvlist_add_uint64(*config,
2659                                     ZPOOL_CONFIG_SUSPENDED,
2660                                     spa->spa_failmode) == 0);
2661 
2662                         spa_add_spares(spa, *config);
2663                         spa_add_l2cache(spa, *config);
2664                 }
2665         }
2666 
2667         /*
2668          * We want to get the alternate root even for faulted pools, so we cheat
2669          * and call spa_lookup() directly.
2670          */
2671         if (altroot) {
2672                 if (spa == NULL) {
2673                         mutex_enter(&spa_namespace_lock);
2674                         spa = spa_lookup(name);
2675                         if (spa)
2676                                 spa_altroot(spa, altroot, buflen);
2677                         else
2678                                 altroot[0] = '\0';
2679                         spa = NULL;
2680                         mutex_exit(&spa_namespace_lock);
2681                 } else {
2682                         spa_altroot(spa, altroot, buflen);
2683                 }
2684         }
2685 
2686         if (spa != NULL) {
2687                 spa_config_exit(spa, SCL_CONFIG, FTAG);
2688                 spa_close(spa, FTAG);
2689         }
2690 
2691         return (error);
2692 }
2693 
2694 /*
2695  * Validate that the auxiliary device array is well formed.  We must have an
2696  * array of nvlists, each which describes a valid leaf vdev.  If this is an
2697  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
2698  * specified, as long as they are well-formed.
2699  */
2700 static int
2701 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
2702     spa_aux_vdev_t *sav, const char *config, uint64_t version,
2703     vdev_labeltype_t label)
2704 {
2705         nvlist_t **dev;
2706         uint_t i, ndev;
2707         vdev_t *vd;
2708         int error;
2709 
2710         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
2711 
2712         /*
2713          * It's acceptable to have no devs specified.
2714          */
2715         if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
2716                 return (0);
2717 
2718         if (ndev == 0)
2719                 return (EINVAL);
2720 
2721         /*
2722          * Make sure the pool is formatted with a version that supports this
2723          * device type.
2724          */
2725         if (spa_version(spa) < version)
2726                 return (ENOTSUP);
2727 
2728         /*
2729          * Set the pending device list so we correctly handle device in-use
2730          * checking.
2731          */
2732         sav->sav_pending = dev;
2733         sav->sav_npending = ndev;
2734 
2735         for (i = 0; i < ndev; i++) {
2736                 if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
2737                     mode)) != 0)
2738                         goto out;
2739 
2740                 if (!vd->vdev_ops->vdev_op_leaf) {
2741                         vdev_free(vd);
2742                         error = EINVAL;
2743                         goto out;
2744                 }
2745 
2746                 /*
2747                  * The L2ARC currently only supports disk devices in
2748                  * kernel context.  For user-level testing, we allow it.
2749                  */
2750 #ifdef _KERNEL
2751                 if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
2752                     strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
2753                         error = ENOTBLK;
2754                         goto out;
2755                 }
2756 #endif
2757                 vd->vdev_top = vd;
2758 
2759                 if ((error = vdev_open(vd)) == 0 &&
2760                     (error = vdev_label_init(vd, crtxg, label)) == 0) {
2761                         VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
2762                             vd->vdev_guid) == 0);
2763                 }
2764 
2765                 vdev_free(vd);
2766 
2767                 if (error &&
2768                     (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
2769                         goto out;
2770                 else
2771                         error = 0;
2772         }
2773 
2774 out:
2775         sav->sav_pending = NULL;
2776         sav->sav_npending = 0;
2777         return (error);
2778 }
2779 
2780 static int
2781 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
2782 {
2783         int error;
2784 
2785         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
2786 
2787         if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
2788             &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
2789             VDEV_LABEL_SPARE)) != 0) {
2790                 return (error);
2791         }
2792 
2793         return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
2794             &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
2795             VDEV_LABEL_L2CACHE));
2796 }
2797 
2798 static void
2799 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
2800     const char *config)
2801 {
2802         int i;
2803 
2804         if (sav->sav_config != NULL) {
2805                 nvlist_t **olddevs;
2806                 uint_t oldndevs;
2807                 nvlist_t **newdevs;
2808 
2809                 /*
2810                  * Generate new dev list by concatentating with the
2811                  * current dev list.
2812                  */
2813                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
2814                     &olddevs, &oldndevs) == 0);
2815 
2816                 newdevs = kmem_alloc(sizeof (void *) *
2817                     (ndevs + oldndevs), KM_SLEEP);
2818                 for (i = 0; i < oldndevs; i++)
2819                         VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
2820                             KM_SLEEP) == 0);
2821                 for (i = 0; i < ndevs; i++)
2822                         VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
2823                             KM_SLEEP) == 0);
2824 
2825                 VERIFY(nvlist_remove(sav->sav_config, config,
2826                     DATA_TYPE_NVLIST_ARRAY) == 0);
2827 
2828                 VERIFY(nvlist_add_nvlist_array(sav->sav_config,
2829                     config, newdevs, ndevs + oldndevs) == 0);
2830                 for (i = 0; i < oldndevs + ndevs; i++)
2831                         nvlist_free(newdevs[i]);
2832                 kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
2833         } else {
2834                 /*
2835                  * Generate a new dev list.
2836                  */
2837                 VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
2838                     KM_SLEEP) == 0);
2839                 VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
2840                     devs, ndevs) == 0);
2841         }
2842 }
2843 
2844 /*
2845  * Stop and drop level 2 ARC devices
2846  */
2847 void
2848 spa_l2cache_drop(spa_t *spa)
2849 {
2850         vdev_t *vd;
2851         int i;
2852         spa_aux_vdev_t *sav = &spa->spa_l2cache;
2853 
2854         for (i = 0; i < sav->sav_count; i++) {
2855                 uint64_t pool;
2856 
2857                 vd = sav->sav_vdevs[i];
2858                 ASSERT(vd != NULL);
2859 
2860                 if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
2861                     pool != 0ULL && l2arc_vdev_present(vd))
2862                         l2arc_remove_vdev(vd);
2863                 if (vd->vdev_isl2cache)
2864                         spa_l2cache_remove(vd);
2865                 vdev_clear_stats(vd);
2866                 (void) vdev_close(vd);
2867         }
2868 }
2869 
2870 /*
2871  * Pool Creation
2872  */
2873 int
2874 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
2875     const char *history_str, nvlist_t *zplprops)
2876 {
2877         spa_t *spa;
2878         char *altroot = NULL;
2879         vdev_t *rvd;
2880         dsl_pool_t *dp;
2881         dmu_tx_t *tx;
2882         int error = 0;
2883         uint64_t txg = TXG_INITIAL;
2884         nvlist_t **spares, **l2cache;
2885         uint_t nspares, nl2cache;
2886         uint64_t version, obj;
2887 
2888         /*
2889          * If this pool already exists, return failure.
2890          */
2891         mutex_enter(&spa_namespace_lock);
2892         if (spa_lookup(pool) != NULL) {
2893                 mutex_exit(&spa_namespace_lock);
2894                 return (EEXIST);
2895         }
2896 
2897         /*
2898          * Allocate a new spa_t structure.
2899          */
2900         (void) nvlist_lookup_string(props,
2901             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
2902         spa = spa_add(pool, NULL, altroot);
2903         spa_activate(spa, spa_mode_global);
2904 
2905         if (props && (error = spa_prop_validate(spa, props))) {
2906                 spa_deactivate(spa);
2907                 spa_remove(spa);
2908                 mutex_exit(&spa_namespace_lock);
2909                 return (error);
2910         }
2911 
2912         if (nvlist_lookup_uint64(props, zpool_prop_to_name(ZPOOL_PROP_VERSION),
2913             &version) != 0)
2914                 version = SPA_VERSION;
2915         ASSERT(version <= SPA_VERSION);
2916 
2917         spa->spa_first_txg = txg;
2918         spa->spa_uberblock.ub_txg = txg - 1;
2919         spa->spa_uberblock.ub_version = version;
2920         spa->spa_ubsync = spa->spa_uberblock;
2921 
2922         /*
2923          * Create "The Godfather" zio to hold all async IOs
2924          */
2925         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
2926             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
2927 
2928         /*
2929          * Create the root vdev.
2930          */
2931         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2932 
2933         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
2934 
2935         ASSERT(error != 0 || rvd != NULL);
2936         ASSERT(error != 0 || spa->spa_root_vdev == rvd);
2937 
2938         if (error == 0 && !zfs_allocatable_devs(nvroot))
2939                 error = EINVAL;
2940 
2941         if (error == 0 &&
2942             (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
2943             (error = spa_validate_aux(spa, nvroot, txg,
2944             VDEV_ALLOC_ADD)) == 0) {
2945                 for (int c = 0; c < rvd->vdev_children; c++) {
2946                         vdev_metaslab_set_size(rvd->vdev_child[c]);
2947                         vdev_expand(rvd->vdev_child[c], txg);
2948                 }
2949         }
2950 
2951         spa_config_exit(spa, SCL_ALL, FTAG);
2952 
2953         if (error != 0) {
2954                 spa_unload(spa);
2955                 spa_deactivate(spa);
2956                 spa_remove(spa);
2957                 mutex_exit(&spa_namespace_lock);
2958                 return (error);
2959         }
2960 
2961         /*
2962          * Get the list of spares, if specified.
2963          */
2964         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
2965             &spares, &nspares) == 0) {
2966                 VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
2967                     KM_SLEEP) == 0);
2968                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
2969                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
2970                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2971                 spa_load_spares(spa);
2972                 spa_config_exit(spa, SCL_ALL, FTAG);
2973                 spa->spa_spares.sav_sync = B_TRUE;
2974         }
2975 
2976         /*
2977          * Get the list of level 2 cache devices, if specified.
2978          */
2979         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
2980             &l2cache, &nl2cache) == 0) {
2981                 VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
2982                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
2983                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
2984                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
2985                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2986                 spa_load_l2cache(spa);
2987                 spa_config_exit(spa, SCL_ALL, FTAG);
2988                 spa->spa_l2cache.sav_sync = B_TRUE;
2989         }
2990 
2991         spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
2992         spa->spa_meta_objset = dp->dp_meta_objset;
2993 
2994         /*
2995          * Create DDTs (dedup tables).
2996          */
2997         ddt_create(spa);
2998 
2999         spa_update_dspace(spa);
3000 
3001         tx = dmu_tx_create_assigned(dp, txg);
3002 
3003         /*
3004          * Create the pool config object.
3005          */
3006         spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
3007             DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
3008             DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
3009 
3010         if (zap_add(spa->spa_meta_objset,
3011             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
3012             sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
3013                 cmn_err(CE_PANIC, "failed to add pool config");
3014         }
3015 
3016         if (zap_add(spa->spa_meta_objset,
3017             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
3018             sizeof (uint64_t), 1, &version, tx) != 0) {
3019                 cmn_err(CE_PANIC, "failed to add pool version");
3020         }
3021 
3022         /* Newly created pools with the right version are always deflated. */
3023         if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
3024                 spa->spa_deflate = TRUE;
3025                 if (zap_add(spa->spa_meta_objset,
3026                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
3027                     sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
3028                         cmn_err(CE_PANIC, "failed to add deflate");
3029                 }
3030         }
3031 
3032         /*
3033          * Create the deferred-free bpobj.  Turn off compression
3034          * because sync-to-convergence takes longer if the blocksize
3035          * keeps changing.
3036          */
3037         obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
3038         dmu_object_set_compress(spa->spa_meta_objset, obj,
3039             ZIO_COMPRESS_OFF, tx);
3040         if (zap_add(spa->spa_meta_objset,
3041             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
3042             sizeof (uint64_t), 1, &obj, tx) != 0) {
3043                 cmn_err(CE_PANIC, "failed to add bpobj");
3044         }
3045         VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
3046             spa->spa_meta_objset, obj));
3047 
3048         /*
3049          * Create the pool's history object.
3050          */
3051         if (version >= SPA_VERSION_ZPOOL_HISTORY)
3052                 spa_history_create_obj(spa, tx);
3053 
3054         /*
3055          * Set pool properties.
3056          */
3057         spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
3058         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
3059         spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
3060         spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
3061 
3062         if (props != NULL) {
3063                 spa_configfile_set(spa, props, B_FALSE);
3064                 spa_sync_props(spa, props, tx);
3065         }
3066 
3067         dmu_tx_commit(tx);
3068 
3069         spa->spa_sync_on = B_TRUE;
3070         txg_sync_start(spa->spa_dsl_pool);
3071 
3072         /*
3073          * We explicitly wait for the first transaction to complete so that our
3074          * bean counters are appropriately updated.
3075          */
3076         txg_wait_synced(spa->spa_dsl_pool, txg);
3077 
3078         spa_config_sync(spa, B_FALSE, B_TRUE);
3079 
3080         if (version >= SPA_VERSION_ZPOOL_HISTORY && history_str != NULL)
3081                 (void) spa_history_log(spa, history_str, LOG_CMD_POOL_CREATE);
3082         spa_history_log_version(spa, LOG_POOL_CREATE);
3083 
3084         spa->spa_minref = refcount_count(&spa->spa_refcount);
3085 
3086         mutex_exit(&spa_namespace_lock);
3087 
3088         return (0);
3089 }
3090 
3091 #ifdef _KERNEL
3092 /*
3093  * Get the root pool information from the root disk, then import the root pool
3094  * during the system boot up time.
3095  */
3096 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
3097 
3098 static nvlist_t *
3099 spa_generate_rootconf(char *devpath, char *devid, uint64_t *guid)
3100 {
3101         nvlist_t *config;
3102         nvlist_t *nvtop, *nvroot;
3103         uint64_t pgid;
3104 
3105         if (vdev_disk_read_rootlabel(devpath, devid, &config) != 0)
3106                 return (NULL);
3107 
3108         /*
3109          * Add this top-level vdev to the child array.
3110          */
3111         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3112             &nvtop) == 0);
3113         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
3114             &pgid) == 0);
3115         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, guid) == 0);
3116 
3117         /*
3118          * Put this pool's top-level vdevs into a root vdev.
3119          */
3120         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3121         VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
3122             VDEV_TYPE_ROOT) == 0);
3123         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
3124         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
3125         VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
3126             &nvtop, 1) == 0);
3127 
3128         /*
3129          * Replace the existing vdev_tree with the new root vdev in
3130          * this pool's configuration (remove the old, add the new).
3131          */
3132         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
3133         nvlist_free(nvroot);
3134         return (config);
3135 }
3136 
3137 /*
3138  * Walk the vdev tree and see if we can find a device with "better"
3139  * configuration. A configuration is "better" if the label on that
3140  * device has a more recent txg.
3141  */
3142 static void
3143 spa_alt_rootvdev(vdev_t *vd, vdev_t **avd, uint64_t *txg)
3144 {
3145         for (int c = 0; c < vd->vdev_children; c++)
3146                 spa_alt_rootvdev(vd->vdev_child[c], avd, txg);
3147 
3148         if (vd->vdev_ops->vdev_op_leaf) {
3149                 nvlist_t *label;
3150                 uint64_t label_txg;
3151 
3152                 if (vdev_disk_read_rootlabel(vd->vdev_physpath, vd->vdev_devid,
3153                     &label) != 0)
3154                         return;
3155 
3156                 VERIFY(nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
3157                     &label_txg) == 0);
3158 
3159                 /*
3160                  * Do we have a better boot device?
3161                  */
3162                 if (label_txg > *txg) {
3163                         *txg = label_txg;
3164                         *avd = vd;
3165                 }
3166                 nvlist_free(label);
3167         }
3168 }
3169 
3170 /*
3171  * Import a root pool.
3172  *
3173  * For x86. devpath_list will consist of devid and/or physpath name of
3174  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
3175  * The GRUB "findroot" command will return the vdev we should boot.
3176  *
3177  * For Sparc, devpath_list consists the physpath name of the booting device
3178  * no matter the rootpool is a single device pool or a mirrored pool.
3179  * e.g.
3180  *      "/pci@1f,0/ide@d/disk@0,0:a"
3181  */
3182 int
3183 spa_import_rootpool(char *devpath, char *devid)
3184 {
3185         spa_t *spa;
3186         vdev_t *rvd, *bvd, *avd = NULL;
3187         nvlist_t *config, *nvtop;
3188         uint64_t guid, txg;
3189         char *pname;
3190         int error;
3191 
3192         /*
3193          * Read the label from the boot device and generate a configuration.
3194          */
3195         config = spa_generate_rootconf(devpath, devid, &guid);
3196 #if defined(_OBP) && defined(_KERNEL)
3197         if (config == NULL) {
3198                 if (strstr(devpath, "/iscsi/ssd") != NULL) {
3199                         /* iscsi boot */
3200                         get_iscsi_bootpath_phy(devpath);
3201                         config = spa_generate_rootconf(devpath, devid, &guid);
3202                 }
3203         }
3204 #endif
3205         if (config == NULL) {
3206                 cmn_err(CE_NOTE, "Can not read the pool label from '%s'",
3207                     devpath);
3208                 return (EIO);
3209         }
3210 
3211         VERIFY(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
3212             &pname) == 0);
3213         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
3214 
3215         mutex_enter(&spa_namespace_lock);
3216         if ((spa = spa_lookup(pname)) != NULL) {
3217                 /*
3218                  * Remove the existing root pool from the namespace so that we
3219                  * can replace it with the correct config we just read in.
3220                  */
3221                 spa_remove(spa);
3222         }
3223 
3224         spa = spa_add(pname, config, NULL);
3225         spa->spa_is_root = B_TRUE;
3226         spa->spa_import_flags = ZFS_IMPORT_VERBATIM;
3227 
3228         /*
3229          * Build up a vdev tree based on the boot device's label config.
3230          */
3231         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3232             &nvtop) == 0);
3233         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3234         error = spa_config_parse(spa, &rvd, nvtop, NULL, 0,
3235             VDEV_ALLOC_ROOTPOOL);
3236         spa_config_exit(spa, SCL_ALL, FTAG);
3237         if (error) {
3238                 mutex_exit(&spa_namespace_lock);
3239                 nvlist_free(config);
3240                 cmn_err(CE_NOTE, "Can not parse the config for pool '%s'",
3241                     pname);
3242                 return (error);
3243         }
3244 
3245         /*
3246          * Get the boot vdev.
3247          */
3248         if ((bvd = vdev_lookup_by_guid(rvd, guid)) == NULL) {
3249                 cmn_err(CE_NOTE, "Can not find the boot vdev for guid %llu",
3250                     (u_longlong_t)guid);
3251                 error = ENOENT;
3252                 goto out;
3253         }
3254 
3255         /*
3256          * Determine if there is a better boot device.
3257          */
3258         avd = bvd;
3259         spa_alt_rootvdev(rvd, &avd, &txg);
3260         if (avd != bvd) {
3261                 cmn_err(CE_NOTE, "The boot device is 'degraded'. Please "
3262                     "try booting from '%s'", avd->vdev_path);
3263                 error = EINVAL;
3264                 goto out;
3265         }
3266 
3267         /*
3268          * If the boot device is part of a spare vdev then ensure that
3269          * we're booting off the active spare.
3270          */
3271         if (bvd->vdev_parent->vdev_ops == &vdev_spare_ops &&
3272             !bvd->vdev_isspare) {
3273                 cmn_err(CE_NOTE, "The boot device is currently spared. Please "
3274                     "try booting from '%s'",
3275                     bvd->vdev_parent->
3276                     vdev_child[bvd->vdev_parent->vdev_children - 1]->vdev_path);
3277                 error = EINVAL;
3278                 goto out;
3279         }
3280 
3281         error = 0;
3282         spa_history_log_version(spa, LOG_POOL_IMPORT);
3283 out:
3284         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3285         vdev_free(rvd);
3286         spa_config_exit(spa, SCL_ALL, FTAG);
3287         mutex_exit(&spa_namespace_lock);
3288 
3289         nvlist_free(config);
3290         return (error);
3291 }
3292 
3293 #endif
3294 
3295 /*
3296  * Import a non-root pool into the system.
3297  */
3298 int
3299 spa_import(const char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
3300 {
3301         spa_t *spa;
3302         char *altroot = NULL;
3303         spa_load_state_t state = SPA_LOAD_IMPORT;
3304         zpool_rewind_policy_t policy;
3305         uint64_t mode = spa_mode_global;
3306         uint64_t readonly = B_FALSE;
3307         int error;
3308         nvlist_t *nvroot;
3309         nvlist_t **spares, **l2cache;
3310         uint_t nspares, nl2cache;
3311 
3312         /*
3313          * If a pool with this name exists, return failure.
3314          */
3315         mutex_enter(&spa_namespace_lock);
3316         if (spa_lookup(pool) != NULL) {
3317                 mutex_exit(&spa_namespace_lock);
3318                 return (EEXIST);
3319         }
3320 
3321         /*
3322          * Create and initialize the spa structure.
3323          */
3324         (void) nvlist_lookup_string(props,
3325             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3326         (void) nvlist_lookup_uint64(props,
3327             zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
3328         if (readonly)
3329                 mode = FREAD;
3330         spa = spa_add(pool, config, altroot);
3331         spa->spa_import_flags = flags;
3332 
3333         /*
3334          * Verbatim import - Take a pool and insert it into the namespace
3335          * as if it had been loaded at boot.
3336          */
3337         if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
3338                 if (props != NULL)
3339                         spa_configfile_set(spa, props, B_FALSE);
3340 
3341                 spa_config_sync(spa, B_FALSE, B_TRUE);
3342 
3343                 mutex_exit(&spa_namespace_lock);
3344                 spa_history_log_version(spa, LOG_POOL_IMPORT);
3345 
3346                 return (0);
3347         }
3348 
3349         spa_activate(spa, mode);
3350 
3351         /*
3352          * Don't start async tasks until we know everything is healthy.
3353          */
3354         spa_async_suspend(spa);
3355 
3356         zpool_get_rewind_policy(config, &policy);
3357         if (policy.zrp_request & ZPOOL_DO_REWIND)
3358                 state = SPA_LOAD_RECOVER;
3359 
3360         /*
3361          * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
3362          * because the user-supplied config is actually the one to trust when
3363          * doing an import.
3364          */
3365         if (state != SPA_LOAD_RECOVER)
3366                 spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
3367 
3368         error = spa_load_best(spa, state, B_TRUE, policy.zrp_txg,
3369             policy.zrp_request);
3370 
3371         /*
3372          * Propagate anything learned while loading the pool and pass it
3373          * back to caller (i.e. rewind info, missing devices, etc).
3374          */
3375         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
3376             spa->spa_load_info) == 0);
3377 
3378         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3379         /*
3380          * Toss any existing sparelist, as it doesn't have any validity
3381          * anymore, and conflicts with spa_has_spare().
3382          */
3383         if (spa->spa_spares.sav_config) {
3384                 nvlist_free(spa->spa_spares.sav_config);
3385                 spa->spa_spares.sav_config = NULL;
3386                 spa_load_spares(spa);
3387         }
3388         if (spa->spa_l2cache.sav_config) {
3389                 nvlist_free(spa->spa_l2cache.sav_config);
3390                 spa->spa_l2cache.sav_config = NULL;
3391                 spa_load_l2cache(spa);
3392         }
3393 
3394         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3395             &nvroot) == 0);
3396         if (error == 0)
3397                 error = spa_validate_aux(spa, nvroot, -1ULL,
3398                     VDEV_ALLOC_SPARE);
3399         if (error == 0)
3400                 error = spa_validate_aux(spa, nvroot, -1ULL,
3401                     VDEV_ALLOC_L2CACHE);
3402         spa_config_exit(spa, SCL_ALL, FTAG);
3403 
3404         if (props != NULL)
3405                 spa_configfile_set(spa, props, B_FALSE);
3406 
3407         if (error != 0 || (props && spa_writeable(spa) &&
3408             (error = spa_prop_set(spa, props)))) {
3409                 spa_unload(spa);
3410                 spa_deactivate(spa);
3411                 spa_remove(spa);
3412                 mutex_exit(&spa_namespace_lock);
3413                 return (error);
3414         }
3415 
3416         spa_async_resume(spa);
3417 
3418         /*
3419          * Override any spares and level 2 cache devices as specified by
3420          * the user, as these may have correct device names/devids, etc.
3421          */
3422         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3423             &spares, &nspares) == 0) {
3424                 if (spa->spa_spares.sav_config)
3425                         VERIFY(nvlist_remove(spa->spa_spares.sav_config,
3426                             ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
3427                 else
3428                         VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
3429                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
3430                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3431                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3432                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3433                 spa_load_spares(spa);
3434                 spa_config_exit(spa, SCL_ALL, FTAG);
3435                 spa->spa_spares.sav_sync = B_TRUE;
3436         }
3437         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3438             &l2cache, &nl2cache) == 0) {
3439                 if (spa->spa_l2cache.sav_config)
3440                         VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
3441                             ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
3442                 else
3443                         VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3444                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
3445                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3446                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3447                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3448                 spa_load_l2cache(spa);
3449                 spa_config_exit(spa, SCL_ALL, FTAG);
3450                 spa->spa_l2cache.sav_sync = B_TRUE;
3451         }
3452 
3453         /*
3454          * Check for any removed devices.
3455          */
3456         if (spa->spa_autoreplace) {
3457                 spa_aux_check_removed(&spa->spa_spares);
3458                 spa_aux_check_removed(&spa->spa_l2cache);
3459         }
3460 
3461         if (spa_writeable(spa)) {
3462                 /*
3463                  * Update the config cache to include the newly-imported pool.
3464                  */
3465                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
3466         }
3467 
3468         /*
3469          * It's possible that the pool was expanded while it was exported.
3470          * We kick off an async task to handle this for us.
3471          */
3472         spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
3473 
3474         mutex_exit(&spa_namespace_lock);
3475         spa_history_log_version(spa, LOG_POOL_IMPORT);
3476 
3477         return (0);
3478 }
3479 
3480 nvlist_t *
3481 spa_tryimport(nvlist_t *tryconfig)
3482 {
3483         nvlist_t *config = NULL;
3484         char *poolname;
3485         spa_t *spa;
3486         uint64_t state;
3487         int error;
3488 
3489         if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
3490                 return (NULL);
3491 
3492         if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
3493                 return (NULL);
3494 
3495         /*
3496          * Create and initialize the spa structure.
3497          */
3498         mutex_enter(&spa_namespace_lock);
3499         spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
3500         spa_activate(spa, FREAD);
3501 
3502         /*
3503          * Pass off the heavy lifting to spa_load().
3504          * Pass TRUE for mosconfig because the user-supplied config
3505          * is actually the one to trust when doing an import.
3506          */
3507         error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING, B_TRUE);
3508 
3509         /*
3510          * If 'tryconfig' was at least parsable, return the current config.
3511          */
3512         if (spa->spa_root_vdev != NULL) {
3513                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
3514                 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
3515                     poolname) == 0);
3516                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
3517                     state) == 0);
3518                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
3519                     spa->spa_uberblock.ub_timestamp) == 0);
3520 
3521                 /*
3522                  * If the bootfs property exists on this pool then we
3523                  * copy it out so that external consumers can tell which
3524                  * pools are bootable.
3525                  */
3526                 if ((!error || error == EEXIST) && spa->spa_bootfs) {
3527                         char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
3528 
3529                         /*
3530                          * We have to play games with the name since the
3531                          * pool was opened as TRYIMPORT_NAME.
3532                          */
3533                         if (dsl_dsobj_to_dsname(spa_name(spa),
3534                             spa->spa_bootfs, tmpname) == 0) {
3535                                 char *cp;
3536                                 char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
3537 
3538                                 cp = strchr(tmpname, '/');
3539                                 if (cp == NULL) {
3540                                         (void) strlcpy(dsname, tmpname,
3541                                             MAXPATHLEN);
3542                                 } else {
3543                                         (void) snprintf(dsname, MAXPATHLEN,
3544                                             "%s/%s", poolname, ++cp);
3545                                 }
3546                                 VERIFY(nvlist_add_string(config,
3547                                     ZPOOL_CONFIG_BOOTFS, dsname) == 0);
3548                                 kmem_free(dsname, MAXPATHLEN);
3549                         }
3550                         kmem_free(tmpname, MAXPATHLEN);
3551                 }
3552 
3553                 /*
3554                  * Add the list of hot spares and level 2 cache devices.
3555                  */
3556                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3557                 spa_add_spares(spa, config);
3558                 spa_add_l2cache(spa, config);
3559                 spa_config_exit(spa, SCL_CONFIG, FTAG);
3560         }
3561 
3562         spa_unload(spa);
3563         spa_deactivate(spa);
3564         spa_remove(spa);
3565         mutex_exit(&spa_namespace_lock);
3566 
3567         return (config);
3568 }
3569 
3570 /*
3571  * Pool export/destroy
3572  *
3573  * The act of destroying or exporting a pool is very simple.  We make sure there
3574  * is no more pending I/O and any references to the pool are gone.  Then, we
3575  * update the pool state and sync all the labels to disk, removing the
3576  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
3577  * we don't sync the labels or remove the configuration cache.
3578  */
3579 static int
3580 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
3581     boolean_t force, boolean_t hardforce)
3582 {
3583         spa_t *spa;
3584 
3585         if (oldconfig)
3586                 *oldconfig = NULL;
3587 
3588         if (!(spa_mode_global & FWRITE))
3589                 return (EROFS);
3590 
3591         mutex_enter(&spa_namespace_lock);
3592         if ((spa = spa_lookup(pool)) == NULL) {
3593                 mutex_exit(&spa_namespace_lock);
3594                 return (ENOENT);
3595         }
3596 
3597         /*
3598          * Put a hold on the pool, drop the namespace lock, stop async tasks,
3599          * reacquire the namespace lock, and see if we can export.
3600          */
3601         spa_open_ref(spa, FTAG);
3602         mutex_exit(&spa_namespace_lock);
3603         spa_async_suspend(spa);
3604         mutex_enter(&spa_namespace_lock);
3605         spa_close(spa, FTAG);
3606 
3607         /*
3608          * The pool will be in core if it's openable,
3609          * in which case we can modify its state.
3610          */
3611         if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
3612                 /*
3613                  * Objsets may be open only because they're dirty, so we
3614                  * have to force it to sync before checking spa_refcnt.
3615                  */
3616                 txg_wait_synced(spa->spa_dsl_pool, 0);
3617 
3618                 /*
3619                  * A pool cannot be exported or destroyed if there are active
3620                  * references.  If we are resetting a pool, allow references by
3621                  * fault injection handlers.
3622                  */
3623                 if (!spa_refcount_zero(spa) ||
3624                     (spa->spa_inject_ref != 0 &&
3625                     new_state != POOL_STATE_UNINITIALIZED)) {
3626                         spa_async_resume(spa);
3627                         mutex_exit(&spa_namespace_lock);
3628                         return (EBUSY);
3629                 }
3630 
3631                 /*
3632                  * A pool cannot be exported if it has an active shared spare.
3633                  * This is to prevent other pools stealing the active spare
3634                  * from an exported pool. At user's own will, such pool can
3635                  * be forcedly exported.
3636                  */
3637                 if (!force && new_state == POOL_STATE_EXPORTED &&
3638                     spa_has_active_shared_spare(spa)) {
3639                         spa_async_resume(spa);
3640                         mutex_exit(&spa_namespace_lock);
3641                         return (EXDEV);
3642                 }
3643 
3644                 /*
3645                  * We want this to be reflected on every label,
3646                  * so mark them all dirty.  spa_unload() will do the
3647                  * final sync that pushes these changes out.
3648                  */
3649                 if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
3650                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3651                         spa->spa_state = new_state;
3652                         spa->spa_final_txg = spa_last_synced_txg(spa) +
3653                             TXG_DEFER_SIZE + 1;
3654                         vdev_config_dirty(spa->spa_root_vdev);
3655                         spa_config_exit(spa, SCL_ALL, FTAG);
3656                 }
3657         }
3658 
3659         spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
3660 
3661         if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
3662                 spa_unload(spa);
3663                 spa_deactivate(spa);
3664         }
3665 
3666         if (oldconfig && spa->spa_config)
3667                 VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
3668 
3669         if (new_state != POOL_STATE_UNINITIALIZED) {
3670                 if (!hardforce)
3671                         spa_config_sync(spa, B_TRUE, B_TRUE);
3672                 spa_remove(spa);
3673         }
3674         mutex_exit(&spa_namespace_lock);
3675 
3676         return (0);
3677 }
3678 
3679 /*
3680  * Destroy a storage pool.
3681  */
3682 int
3683 spa_destroy(char *pool)
3684 {
3685         return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
3686             B_FALSE, B_FALSE));
3687 }
3688 
3689 /*
3690  * Export a storage pool.
3691  */
3692 int
3693 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
3694     boolean_t hardforce)
3695 {
3696         return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
3697             force, hardforce));
3698 }
3699 
3700 /*
3701  * Similar to spa_export(), this unloads the spa_t without actually removing it
3702  * from the namespace in any way.
3703  */
3704 int
3705 spa_reset(char *pool)
3706 {
3707         return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
3708             B_FALSE, B_FALSE));
3709 }
3710 
3711 /*
3712  * ==========================================================================
3713  * Device manipulation
3714  * ==========================================================================
3715  */
3716 
3717 /*
3718  * Add a device to a storage pool.
3719  */
3720 int
3721 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
3722 {
3723         uint64_t txg, id;
3724         int error;
3725         vdev_t *rvd = spa->spa_root_vdev;
3726         vdev_t *vd, *tvd;
3727         nvlist_t **spares, **l2cache;
3728         uint_t nspares, nl2cache;
3729 
3730         ASSERT(spa_writeable(spa));
3731 
3732         txg = spa_vdev_enter(spa);
3733 
3734         if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
3735             VDEV_ALLOC_ADD)) != 0)
3736                 return (spa_vdev_exit(spa, NULL, txg, error));
3737 
3738         spa->spa_pending_vdev = vd;  /* spa_vdev_exit() will clear this */
3739 
3740         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
3741             &nspares) != 0)
3742                 nspares = 0;
3743 
3744         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
3745             &nl2cache) != 0)
3746                 nl2cache = 0;
3747 
3748         if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
3749                 return (spa_vdev_exit(spa, vd, txg, EINVAL));
3750 
3751         if (vd->vdev_children != 0 &&
3752             (error = vdev_create(vd, txg, B_FALSE)) != 0)
3753                 return (spa_vdev_exit(spa, vd, txg, error));
3754 
3755         /*
3756          * We must validate the spares and l2cache devices after checking the
3757          * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
3758          */
3759         if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
3760                 return (spa_vdev_exit(spa, vd, txg, error));
3761 
3762         /*
3763          * Transfer each new top-level vdev from vd to rvd.
3764          */
3765         for (int c = 0; c < vd->vdev_children; c++) {
3766 
3767                 /*
3768                  * Set the vdev id to the first hole, if one exists.
3769                  */
3770                 for (id = 0; id < rvd->vdev_children; id++) {
3771                         if (rvd->vdev_child[id]->vdev_ishole) {
3772                                 vdev_free(rvd->vdev_child[id]);
3773                                 break;
3774                         }
3775                 }
3776                 tvd = vd->vdev_child[c];
3777                 vdev_remove_child(vd, tvd);
3778                 tvd->vdev_id = id;
3779                 vdev_add_child(rvd, tvd);
3780                 vdev_config_dirty(tvd);
3781         }
3782 
3783         if (nspares != 0) {
3784                 spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
3785                     ZPOOL_CONFIG_SPARES);
3786                 spa_load_spares(spa);
3787                 spa->spa_spares.sav_sync = B_TRUE;
3788         }
3789 
3790         if (nl2cache != 0) {
3791                 spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
3792                     ZPOOL_CONFIG_L2CACHE);
3793                 spa_load_l2cache(spa);
3794                 spa->spa_l2cache.sav_sync = B_TRUE;
3795         }
3796 
3797         /*
3798          * We have to be careful when adding new vdevs to an existing pool.
3799          * If other threads start allocating from these vdevs before we
3800          * sync the config cache, and we lose power, then upon reboot we may
3801          * fail to open the pool because there are DVAs that the config cache
3802          * can't translate.  Therefore, we first add the vdevs without
3803          * initializing metaslabs; sync the config cache (via spa_vdev_exit());
3804          * and then let spa_config_update() initialize the new metaslabs.
3805          *
3806          * spa_load() checks for added-but-not-initialized vdevs, so that
3807          * if we lose power at any point in this sequence, the remaining
3808          * steps will be completed the next time we load the pool.
3809          */
3810         (void) spa_vdev_exit(spa, vd, txg, 0);
3811 
3812         mutex_enter(&spa_namespace_lock);
3813         spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
3814         mutex_exit(&spa_namespace_lock);
3815 
3816         return (0);
3817 }
3818 
3819 /*
3820  * Attach a device to a mirror.  The arguments are the path to any device
3821  * in the mirror, and the nvroot for the new device.  If the path specifies
3822  * a device that is not mirrored, we automatically insert the mirror vdev.
3823  *
3824  * If 'replacing' is specified, the new device is intended to replace the
3825  * existing device; in this case the two devices are made into their own
3826  * mirror using the 'replacing' vdev, which is functionally identical to
3827  * the mirror vdev (it actually reuses all the same ops) but has a few
3828  * extra rules: you can't attach to it after it's been created, and upon
3829  * completion of resilvering, the first disk (the one being replaced)
3830  * is automatically detached.
3831  */
3832 int
3833 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
3834 {
3835         uint64_t txg, dtl_max_txg;
3836         vdev_t *rvd = spa->spa_root_vdev;
3837         vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
3838         vdev_ops_t *pvops;
3839         char *oldvdpath, *newvdpath;
3840         int newvd_isspare;
3841         int error;
3842 
3843         ASSERT(spa_writeable(spa));
3844 
3845         txg = spa_vdev_enter(spa);
3846 
3847         oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
3848 
3849         if (oldvd == NULL)
3850                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
3851 
3852         if (!oldvd->vdev_ops->vdev_op_leaf)
3853                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
3854 
3855         pvd = oldvd->vdev_parent;
3856 
3857         if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
3858             VDEV_ALLOC_ADD)) != 0)
3859                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
3860 
3861         if (newrootvd->vdev_children != 1)
3862                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
3863 
3864         newvd = newrootvd->vdev_child[0];
3865 
3866         if (!newvd->vdev_ops->vdev_op_leaf)
3867                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
3868 
3869         if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
3870                 return (spa_vdev_exit(spa, newrootvd, txg, error));
3871 
3872         /*
3873          * Spares can't replace logs
3874          */
3875         if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
3876                 return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
3877 
3878         if (!replacing) {
3879                 /*
3880                  * For attach, the only allowable parent is a mirror or the root
3881                  * vdev.
3882                  */
3883                 if (pvd->vdev_ops != &vdev_mirror_ops &&
3884                     pvd->vdev_ops != &vdev_root_ops)
3885                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
3886 
3887                 pvops = &vdev_mirror_ops;
3888         } else {
3889                 /*
3890                  * Active hot spares can only be replaced by inactive hot
3891                  * spares.
3892                  */
3893                 if (pvd->vdev_ops == &vdev_spare_ops &&
3894                     oldvd->vdev_isspare &&
3895                     !spa_has_spare(spa, newvd->vdev_guid))
3896                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
3897 
3898                 /*
3899                  * If the source is a hot spare, and the parent isn't already a
3900                  * spare, then we want to create a new hot spare.  Otherwise, we
3901                  * want to create a replacing vdev.  The user is not allowed to
3902                  * attach to a spared vdev child unless the 'isspare' state is
3903                  * the same (spare replaces spare, non-spare replaces
3904                  * non-spare).
3905                  */
3906                 if (pvd->vdev_ops == &vdev_replacing_ops &&
3907                     spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
3908                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
3909                 } else if (pvd->vdev_ops == &vdev_spare_ops &&
3910                     newvd->vdev_isspare != oldvd->vdev_isspare) {
3911                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
3912                 }
3913 
3914                 if (newvd->vdev_isspare)
3915                         pvops = &vdev_spare_ops;
3916                 else
3917                         pvops = &vdev_replacing_ops;
3918         }
3919 
3920         /*
3921          * Make sure the new device is big enough.
3922          */
3923         if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
3924                 return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
3925 
3926         /*
3927          * The new device cannot have a higher alignment requirement
3928          * than the top-level vdev.
3929          */
3930         if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
3931                 return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
3932 
3933         /*
3934          * If this is an in-place replacement, update oldvd's path and devid
3935          * to make it distinguishable from newvd, and unopenable from now on.
3936          */
3937         if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
3938                 spa_strfree(oldvd->vdev_path);
3939                 oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
3940                     KM_SLEEP);
3941                 (void) sprintf(oldvd->vdev_path, "%s/%s",
3942                     newvd->vdev_path, "old");
3943                 if (oldvd->vdev_devid != NULL) {
3944                         spa_strfree(oldvd->vdev_devid);
3945                         oldvd->vdev_devid = NULL;
3946                 }
3947         }
3948 
3949         /* mark the device being resilvered */
3950         newvd->vdev_resilvering = B_TRUE;
3951 
3952         /*
3953          * If the parent is not a mirror, or if we're replacing, insert the new
3954          * mirror/replacing/spare vdev above oldvd.
3955          */
3956         if (pvd->vdev_ops != pvops)
3957                 pvd = vdev_add_parent(oldvd, pvops);
3958 
3959         ASSERT(pvd->vdev_top->vdev_parent == rvd);
3960         ASSERT(pvd->vdev_ops == pvops);
3961         ASSERT(oldvd->vdev_parent == pvd);
3962 
3963         /*
3964          * Extract the new device from its root and add it to pvd.
3965          */
3966         vdev_remove_child(newrootvd, newvd);
3967         newvd->vdev_id = pvd->vdev_children;
3968         newvd->vdev_crtxg = oldvd->vdev_crtxg;
3969         vdev_add_child(pvd, newvd);
3970 
3971         tvd = newvd->vdev_top;
3972         ASSERT(pvd->vdev_top == tvd);
3973         ASSERT(tvd->vdev_parent == rvd);
3974 
3975         vdev_config_dirty(tvd);
3976 
3977         /*
3978          * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
3979          * for any dmu_sync-ed blocks.  It will propagate upward when
3980          * spa_vdev_exit() calls vdev_dtl_reassess().
3981          */
3982         dtl_max_txg = txg + TXG_CONCURRENT_STATES;
3983 
3984         vdev_dtl_dirty(newvd, DTL_MISSING, TXG_INITIAL,
3985             dtl_max_txg - TXG_INITIAL);
3986 
3987         if (newvd->vdev_isspare) {
3988                 spa_spare_activate(newvd);
3989                 spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
3990         }
3991 
3992         oldvdpath = spa_strdup(oldvd->vdev_path);
3993         newvdpath = spa_strdup(newvd->vdev_path);
3994         newvd_isspare = newvd->vdev_isspare;
3995 
3996         /*
3997          * Mark newvd's DTL dirty in this txg.
3998          */
3999         vdev_dirty(tvd, VDD_DTL, newvd, txg);
4000 
4001         /*
4002          * Restart the resilver
4003          */
4004         dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
4005 
4006         /*
4007          * Commit the config
4008          */
4009         (void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
4010 
4011         spa_history_log_internal(LOG_POOL_VDEV_ATTACH, spa, NULL,
4012             "%s vdev=%s %s vdev=%s",
4013             replacing && newvd_isspare ? "spare in" :
4014             replacing ? "replace" : "attach", newvdpath,
4015             replacing ? "for" : "to", oldvdpath);
4016 
4017         spa_strfree(oldvdpath);
4018         spa_strfree(newvdpath);
4019 
4020         if (spa->spa_bootfs)
4021                 spa_event_notify(spa, newvd, ESC_ZFS_BOOTFS_VDEV_ATTACH);
4022 
4023         return (0);
4024 }
4025 
4026 /*
4027  * Detach a device from a mirror or replacing vdev.
4028  * If 'replace_done' is specified, only detach if the parent
4029  * is a replacing vdev.
4030  */
4031 int
4032 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
4033 {
4034         uint64_t txg;
4035         int error;
4036         vdev_t *rvd = spa->spa_root_vdev;
4037         vdev_t *vd, *pvd, *cvd, *tvd;
4038         boolean_t unspare = B_FALSE;
4039         uint64_t unspare_guid;
4040         char *vdpath;
4041 
4042         ASSERT(spa_writeable(spa));
4043 
4044         txg = spa_vdev_enter(spa);
4045 
4046         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4047 
4048         if (vd == NULL)
4049                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4050 
4051         if (!vd->vdev_ops->vdev_op_leaf)
4052                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4053 
4054         pvd = vd->vdev_parent;
4055 
4056         /*
4057          * If the parent/child relationship is not as expected, don't do it.
4058          * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
4059          * vdev that's replacing B with C.  The user's intent in replacing
4060          * is to go from M(A,B) to M(A,C).  If the user decides to cancel
4061          * the replace by detaching C, the expected behavior is to end up
4062          * M(A,B).  But suppose that right after deciding to detach C,
4063          * the replacement of B completes.  We would have M(A,C), and then
4064          * ask to detach C, which would leave us with just A -- not what
4065          * the user wanted.  To prevent this, we make sure that the
4066          * parent/child relationship hasn't changed -- in this example,
4067          * that C's parent is still the replacing vdev R.
4068          */
4069         if (pvd->vdev_guid != pguid && pguid != 0)
4070                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4071 
4072         /*
4073          * Only 'replacing' or 'spare' vdevs can be replaced.
4074          */
4075         if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
4076             pvd->vdev_ops != &vdev_spare_ops)
4077                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4078 
4079         ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
4080             spa_version(spa) >= SPA_VERSION_SPARES);
4081 
4082         /*
4083          * Only mirror, replacing, and spare vdevs support detach.
4084          */
4085         if (pvd->vdev_ops != &vdev_replacing_ops &&
4086             pvd->vdev_ops != &vdev_mirror_ops &&
4087             pvd->vdev_ops != &vdev_spare_ops)
4088                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4089 
4090         /*
4091          * If this device has the only valid copy of some data,
4092          * we cannot safely detach it.
4093          */
4094         if (vdev_dtl_required(vd))
4095                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4096 
4097         ASSERT(pvd->vdev_children >= 2);
4098 
4099         /*
4100          * If we are detaching the second disk from a replacing vdev, then
4101          * check to see if we changed the original vdev's path to have "/old"
4102          * at the end in spa_vdev_attach().  If so, undo that change now.
4103          */
4104         if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
4105             vd->vdev_path != NULL) {
4106                 size_t len = strlen(vd->vdev_path);
4107 
4108                 for (int c = 0; c < pvd->vdev_children; c++) {
4109                         cvd = pvd->vdev_child[c];
4110 
4111                         if (cvd == vd || cvd->vdev_path == NULL)
4112                                 continue;
4113 
4114                         if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
4115                             strcmp(cvd->vdev_path + len, "/old") == 0) {
4116                                 spa_strfree(cvd->vdev_path);
4117                                 cvd->vdev_path = spa_strdup(vd->vdev_path);
4118                                 break;
4119                         }
4120                 }
4121         }
4122 
4123         /*
4124          * If we are detaching the original disk from a spare, then it implies
4125          * that the spare should become a real disk, and be removed from the
4126          * active spare list for the pool.
4127          */
4128         if (pvd->vdev_ops == &vdev_spare_ops &&
4129             vd->vdev_id == 0 &&
4130             pvd->vdev_child[pvd->vdev_children - 1]->vdev_isspare)
4131                 unspare = B_TRUE;
4132 
4133         /*
4134          * Erase the disk labels so the disk can be used for other things.
4135          * This must be done after all other error cases are handled,
4136          * but before we disembowel vd (so we can still do I/O to it).
4137          * But if we can't do it, don't treat the error as fatal --
4138          * it may be that the unwritability of the disk is the reason
4139          * it's being detached!
4140          */
4141         error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4142 
4143         /*
4144          * Remove vd from its parent and compact the parent's children.
4145          */
4146         vdev_remove_child(pvd, vd);
4147         vdev_compact_children(pvd);
4148 
4149         /*
4150          * Remember one of the remaining children so we can get tvd below.
4151          */
4152         cvd = pvd->vdev_child[pvd->vdev_children - 1];
4153 
4154         /*
4155          * If we need to remove the remaining child from the list of hot spares,
4156          * do it now, marking the vdev as no longer a spare in the process.
4157          * We must do this before vdev_remove_parent(), because that can
4158          * change the GUID if it creates a new toplevel GUID.  For a similar
4159          * reason, we must remove the spare now, in the same txg as the detach;
4160          * otherwise someone could attach a new sibling, change the GUID, and
4161          * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
4162          */
4163         if (unspare) {
4164                 ASSERT(cvd->vdev_isspare);
4165                 spa_spare_remove(cvd);
4166                 unspare_guid = cvd->vdev_guid;
4167                 (void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
4168                 cvd->vdev_unspare = B_TRUE;
4169         }
4170 
4171         /*
4172          * If the parent mirror/replacing vdev only has one child,
4173          * the parent is no longer needed.  Remove it from the tree.
4174          */
4175         if (pvd->vdev_children == 1) {
4176                 if (pvd->vdev_ops == &vdev_spare_ops)
4177                         cvd->vdev_unspare = B_FALSE;
4178                 vdev_remove_parent(cvd);
4179                 cvd->vdev_resilvering = B_FALSE;
4180         }
4181 
4182 
4183         /*
4184          * We don't set tvd until now because the parent we just removed
4185          * may have been the previous top-level vdev.
4186          */
4187         tvd = cvd->vdev_top;
4188         ASSERT(tvd->vdev_parent == rvd);
4189 
4190         /*
4191          * Reevaluate the parent vdev state.
4192          */
4193         vdev_propagate_state(cvd);
4194 
4195         /*
4196          * If the 'autoexpand' property is set on the pool then automatically
4197          * try to expand the size of the pool. For example if the device we
4198          * just detached was smaller than the others, it may be possible to
4199          * add metaslabs (i.e. grow the pool). We need to reopen the vdev
4200          * first so that we can obtain the updated sizes of the leaf vdevs.
4201          */
4202         if (spa->spa_autoexpand) {
4203                 vdev_reopen(tvd);
4204                 vdev_expand(tvd, txg);
4205         }
4206 
4207         vdev_config_dirty(tvd);
4208 
4209         /*
4210          * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
4211          * vd->vdev_detached is set and free vd's DTL object in syncing context.
4212          * But first make sure we're not on any *other* txg's DTL list, to
4213          * prevent vd from being accessed after it's freed.
4214          */
4215         vdpath = spa_strdup(vd->vdev_path);
4216         for (int t = 0; t < TXG_SIZE; t++)
4217                 (void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
4218         vd->vdev_detached = B_TRUE;
4219         vdev_dirty(tvd, VDD_DTL, vd, txg);
4220 
4221         spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
4222 
4223         /* hang on to the spa before we release the lock */
4224         spa_open_ref(spa, FTAG);
4225 
4226         error = spa_vdev_exit(spa, vd, txg, 0);
4227 
4228         spa_history_log_internal(LOG_POOL_VDEV_DETACH, spa, NULL,
4229             "vdev=%s", vdpath);
4230         spa_strfree(vdpath);
4231 
4232         /*
4233          * If this was the removal of the original device in a hot spare vdev,
4234          * then we want to go through and remove the device from the hot spare
4235          * list of every other pool.
4236          */
4237         if (unspare) {
4238                 spa_t *altspa = NULL;
4239 
4240                 mutex_enter(&spa_namespace_lock);
4241                 while ((altspa = spa_next(altspa)) != NULL) {
4242                         if (altspa->spa_state != POOL_STATE_ACTIVE ||
4243                             altspa == spa)
4244                                 continue;
4245 
4246                         spa_open_ref(altspa, FTAG);
4247                         mutex_exit(&spa_namespace_lock);
4248                         (void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
4249                         mutex_enter(&spa_namespace_lock);
4250                         spa_close(altspa, FTAG);
4251                 }
4252                 mutex_exit(&spa_namespace_lock);
4253 
4254                 /* search the rest of the vdevs for spares to remove */
4255                 spa_vdev_resilver_done(spa);
4256         }
4257 
4258         /* all done with the spa; OK to release */
4259         mutex_enter(&spa_namespace_lock);
4260         spa_close(spa, FTAG);
4261         mutex_exit(&spa_namespace_lock);
4262 
4263         return (error);
4264 }
4265 
4266 /*
4267  * Split a set of devices from their mirrors, and create a new pool from them.
4268  */
4269 int
4270 spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
4271     nvlist_t *props, boolean_t exp)
4272 {
4273         int error = 0;
4274         uint64_t txg, *glist;
4275         spa_t *newspa;
4276         uint_t c, children, lastlog;
4277         nvlist_t **child, *nvl, *tmp;
4278         dmu_tx_t *tx;
4279         char *altroot = NULL;
4280         vdev_t *rvd, **vml = NULL;                      /* vdev modify list */
4281         boolean_t activate_slog;
4282 
4283         ASSERT(spa_writeable(spa));
4284 
4285         txg = spa_vdev_enter(spa);
4286 
4287         /* clear the log and flush everything up to now */
4288         activate_slog = spa_passivate_log(spa);
4289         (void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4290         error = spa_offline_log(spa);
4291         txg = spa_vdev_config_enter(spa);
4292 
4293         if (activate_slog)
4294                 spa_activate_log(spa);
4295 
4296         if (error != 0)
4297                 return (spa_vdev_exit(spa, NULL, txg, error));
4298 
4299         /* check new spa name before going any further */
4300         if (spa_lookup(newname) != NULL)
4301                 return (spa_vdev_exit(spa, NULL, txg, EEXIST));
4302 
4303         /*
4304          * scan through all the children to ensure they're all mirrors
4305          */
4306         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
4307             nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
4308             &children) != 0)
4309                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4310 
4311         /* first, check to ensure we've got the right child count */
4312         rvd = spa->spa_root_vdev;
4313         lastlog = 0;
4314         for (c = 0; c < rvd->vdev_children; c++) {
4315                 vdev_t *vd = rvd->vdev_child[c];
4316 
4317                 /* don't count the holes & logs as children */
4318                 if (vd->vdev_islog || vd->vdev_ishole) {
4319                         if (lastlog == 0)
4320                                 lastlog = c;
4321                         continue;
4322                 }
4323 
4324                 lastlog = 0;
4325         }
4326         if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
4327                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4328 
4329         /* next, ensure no spare or cache devices are part of the split */
4330         if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
4331             nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
4332                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4333 
4334         vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
4335         glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
4336 
4337         /* then, loop over each vdev and validate it */
4338         for (c = 0; c < children; c++) {
4339                 uint64_t is_hole = 0;
4340 
4341                 (void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
4342                     &is_hole);
4343 
4344                 if (is_hole != 0) {
4345                         if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
4346                             spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
4347                                 continue;
4348                         } else {
4349                                 error = EINVAL;
4350                                 break;
4351                         }
4352                 }
4353 
4354                 /* which disk is going to be split? */
4355                 if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
4356                     &glist[c]) != 0) {
4357                         error = EINVAL;
4358                         break;
4359                 }
4360 
4361                 /* look it up in the spa */
4362                 vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
4363                 if (vml[c] == NULL) {
4364                         error = ENODEV;
4365                         break;
4366                 }
4367 
4368                 /* make sure there's nothing stopping the split */
4369                 if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
4370                     vml[c]->vdev_islog ||
4371                     vml[c]->vdev_ishole ||
4372                     vml[c]->vdev_isspare ||
4373                     vml[c]->vdev_isl2cache ||
4374                     !vdev_writeable(vml[c]) ||
4375                     vml[c]->vdev_children != 0 ||
4376                     vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
4377                     c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
4378                         error = EINVAL;
4379                         break;
4380                 }
4381 
4382                 if (vdev_dtl_required(vml[c])) {
4383                         error = EBUSY;
4384                         break;
4385                 }
4386 
4387                 /* we need certain info from the top level */
4388                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
4389                     vml[c]->vdev_top->vdev_ms_array) == 0);
4390                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
4391                     vml[c]->vdev_top->vdev_ms_shift) == 0);
4392                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
4393                     vml[c]->vdev_top->vdev_asize) == 0);
4394                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
4395                     vml[c]->vdev_top->vdev_ashift) == 0);
4396         }
4397 
4398         if (error != 0) {
4399                 kmem_free(vml, children * sizeof (vdev_t *));
4400                 kmem_free(glist, children * sizeof (uint64_t));
4401                 return (spa_vdev_exit(spa, NULL, txg, error));
4402         }
4403 
4404         /* stop writers from using the disks */
4405         for (c = 0; c < children; c++) {
4406                 if (vml[c] != NULL)
4407                         vml[c]->vdev_offline = B_TRUE;
4408         }
4409         vdev_reopen(spa->spa_root_vdev);
4410 
4411         /*
4412          * Temporarily record the splitting vdevs in the spa config.  This
4413          * will disappear once the config is regenerated.
4414          */
4415         VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0);
4416         VERIFY(nvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
4417             glist, children) == 0);
4418         kmem_free(glist, children * sizeof (uint64_t));
4419 
4420         mutex_enter(&spa->spa_props_lock);
4421         VERIFY(nvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT,
4422             nvl) == 0);
4423         mutex_exit(&spa->spa_props_lock);
4424         spa->spa_config_splitting = nvl;
4425         vdev_config_dirty(spa->spa_root_vdev);
4426 
4427         /* configure and create the new pool */
4428         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname) == 0);
4429         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4430             exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE) == 0);
4431         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
4432             spa_version(spa)) == 0);
4433         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
4434             spa->spa_config_txg) == 0);
4435         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
4436             spa_generate_guid(NULL)) == 0);
4437         (void) nvlist_lookup_string(props,
4438             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
4439 
4440         /* add the new pool to the namespace */
4441         newspa = spa_add(newname, config, altroot);
4442         newspa->spa_config_txg = spa->spa_config_txg;
4443         spa_set_log_state(newspa, SPA_LOG_CLEAR);
4444 
4445         /* release the spa config lock, retaining the namespace lock */
4446         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4447 
4448         if (zio_injection_enabled)
4449                 zio_handle_panic_injection(spa, FTAG, 1);
4450 
4451         spa_activate(newspa, spa_mode_global);
4452         spa_async_suspend(newspa);
4453 
4454         /* create the new pool from the disks of the original pool */
4455         error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE, B_TRUE);
4456         if (error)
4457                 goto out;
4458 
4459         /* if that worked, generate a real config for the new pool */
4460         if (newspa->spa_root_vdev != NULL) {
4461                 VERIFY(nvlist_alloc(&newspa->spa_config_splitting,
4462                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
4463                 VERIFY(nvlist_add_uint64(newspa->spa_config_splitting,
4464                     ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa)) == 0);
4465                 spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
4466                     B_TRUE));
4467         }
4468 
4469         /* set the props */
4470         if (props != NULL) {
4471                 spa_configfile_set(newspa, props, B_FALSE);
4472                 error = spa_prop_set(newspa, props);
4473                 if (error)
4474                         goto out;
4475         }
4476 
4477         /* flush everything */
4478         txg = spa_vdev_config_enter(newspa);
4479         vdev_config_dirty(newspa->spa_root_vdev);
4480         (void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
4481 
4482         if (zio_injection_enabled)
4483                 zio_handle_panic_injection(spa, FTAG, 2);
4484 
4485         spa_async_resume(newspa);
4486 
4487         /* finally, update the original pool's config */
4488         txg = spa_vdev_config_enter(spa);
4489         tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
4490         error = dmu_tx_assign(tx, TXG_WAIT);
4491         if (error != 0)
4492                 dmu_tx_abort(tx);
4493         for (c = 0; c < children; c++) {
4494                 if (vml[c] != NULL) {
4495                         vdev_split(vml[c]);
4496                         if (error == 0)
4497                                 spa_history_log_internal(LOG_POOL_VDEV_DETACH,
4498                                     spa, tx, "vdev=%s",
4499                                     vml[c]->vdev_path);
4500                         vdev_free(vml[c]);
4501                 }
4502         }
4503         vdev_config_dirty(spa->spa_root_vdev);
4504         spa->spa_config_splitting = NULL;
4505         nvlist_free(nvl);
4506         if (error == 0)
4507                 dmu_tx_commit(tx);
4508         (void) spa_vdev_exit(spa, NULL, txg, 0);
4509 
4510         if (zio_injection_enabled)
4511                 zio_handle_panic_injection(spa, FTAG, 3);
4512 
4513         /* split is complete; log a history record */
4514         spa_history_log_internal(LOG_POOL_SPLIT, newspa, NULL,
4515             "split new pool %s from pool %s", newname, spa_name(spa));
4516 
4517         kmem_free(vml, children * sizeof (vdev_t *));
4518 
4519         /* if we're not going to mount the filesystems in userland, export */
4520         if (exp)
4521                 error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
4522                     B_FALSE, B_FALSE);
4523 
4524         return (error);
4525 
4526 out:
4527         spa_unload(newspa);
4528         spa_deactivate(newspa);
4529         spa_remove(newspa);
4530 
4531         txg = spa_vdev_config_enter(spa);
4532 
4533         /* re-online all offlined disks */
4534         for (c = 0; c < children; c++) {
4535                 if (vml[c] != NULL)
4536                         vml[c]->vdev_offline = B_FALSE;
4537         }
4538         vdev_reopen(spa->spa_root_vdev);
4539 
4540         nvlist_free(spa->spa_config_splitting);
4541         spa->spa_config_splitting = NULL;
4542         (void) spa_vdev_exit(spa, NULL, txg, error);
4543 
4544         kmem_free(vml, children * sizeof (vdev_t *));
4545         return (error);
4546 }
4547 
4548 static nvlist_t *
4549 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
4550 {
4551         for (int i = 0; i < count; i++) {
4552                 uint64_t guid;
4553 
4554                 VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
4555                     &guid) == 0);
4556 
4557                 if (guid == target_guid)
4558                         return (nvpp[i]);
4559         }
4560 
4561         return (NULL);
4562 }
4563 
4564 static void
4565 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
4566         nvlist_t *dev_to_remove)
4567 {
4568         nvlist_t **newdev = NULL;
4569 
4570         if (count > 1)
4571                 newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
4572 
4573         for (int i = 0, j = 0; i < count; i++) {
4574                 if (dev[i] == dev_to_remove)
4575                         continue;
4576                 VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
4577         }
4578 
4579         VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
4580         VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
4581 
4582         for (int i = 0; i < count - 1; i++)
4583                 nvlist_free(newdev[i]);
4584 
4585         if (count > 1)
4586                 kmem_free(newdev, (count - 1) * sizeof (void *));
4587 }
4588 
4589 /*
4590  * Evacuate the device.
4591  */
4592 static int
4593 spa_vdev_remove_evacuate(spa_t *spa, vdev_t *vd)
4594 {
4595         uint64_t txg;
4596         int error = 0;
4597 
4598         ASSERT(MUTEX_HELD(&spa_namespace_lock));
4599         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
4600         ASSERT(vd == vd->vdev_top);
4601 
4602         /*
4603          * Evacuate the device.  We don't hold the config lock as writer
4604          * since we need to do I/O but we do keep the
4605          * spa_namespace_lock held.  Once this completes the device
4606          * should no longer have any blocks allocated on it.
4607          */
4608         if (vd->vdev_islog) {
4609                 if (vd->vdev_stat.vs_alloc != 0)
4610                         error = spa_offline_log(spa);
4611         } else {
4612                 error = ENOTSUP;
4613         }
4614 
4615         if (error)
4616                 return (error);
4617 
4618         /*
4619          * The evacuation succeeded.  Remove any remaining MOS metadata
4620          * associated with this vdev, and wait for these changes to sync.
4621          */
4622         ASSERT3U(vd->vdev_stat.vs_alloc, ==, 0);
4623         txg = spa_vdev_config_enter(spa);
4624         vd->vdev_removing = B_TRUE;
4625         vdev_dirty(vd, 0, NULL, txg);
4626         vdev_config_dirty(vd);
4627         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4628 
4629         return (0);
4630 }
4631 
4632 /*
4633  * Complete the removal by cleaning up the namespace.
4634  */
4635 static void
4636 spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
4637 {
4638         vdev_t *rvd = spa->spa_root_vdev;
4639         uint64_t id = vd->vdev_id;
4640         boolean_t last_vdev = (id == (rvd->vdev_children - 1));
4641 
4642         ASSERT(MUTEX_HELD(&spa_namespace_lock));
4643         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
4644         ASSERT(vd == vd->vdev_top);
4645 
4646         /*
4647          * Only remove any devices which are empty.
4648          */
4649         if (vd->vdev_stat.vs_alloc != 0)
4650                 return;
4651 
4652         (void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4653 
4654         if (list_link_active(&vd->vdev_state_dirty_node))
4655                 vdev_state_clean(vd);
4656         if (list_link_active(&vd->vdev_config_dirty_node))
4657                 vdev_config_clean(vd);
4658 
4659         vdev_free(vd);
4660 
4661         if (last_vdev) {
4662                 vdev_compact_children(rvd);
4663         } else {
4664                 vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops);
4665                 vdev_add_child(rvd, vd);
4666         }
4667         vdev_config_dirty(rvd);
4668 
4669         /*
4670          * Reassess the health of our root vdev.
4671          */
4672         vdev_reopen(rvd);
4673 }
4674 
4675 /*
4676  * Remove a device from the pool -
4677  *
4678  * Removing a device from the vdev namespace requires several steps
4679  * and can take a significant amount of time.  As a result we use
4680  * the spa_vdev_config_[enter/exit] functions which allow us to
4681  * grab and release the spa_config_lock while still holding the namespace
4682  * lock.  During each step the configuration is synced out.
4683  */
4684 
4685 /*
4686  * Remove a device from the pool.  Currently, this supports removing only hot
4687  * spares, slogs, and level 2 ARC devices.
4688  */
4689 int
4690 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
4691 {
4692         vdev_t *vd;
4693         metaslab_group_t *mg;
4694         nvlist_t **spares, **l2cache, *nv;
4695         uint64_t txg = 0;
4696         uint_t nspares, nl2cache;
4697         int error = 0;
4698         boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
4699 
4700         ASSERT(spa_writeable(spa));
4701 
4702         if (!locked)
4703                 txg = spa_vdev_enter(spa);
4704 
4705         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4706 
4707         if (spa->spa_spares.sav_vdevs != NULL &&
4708             nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
4709             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
4710             (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
4711                 /*
4712                  * Only remove the hot spare if it's not currently in use
4713                  * in this pool.
4714                  */
4715                 if (vd == NULL || unspare) {
4716                         spa_vdev_remove_aux(spa->spa_spares.sav_config,
4717                             ZPOOL_CONFIG_SPARES, spares, nspares, nv);
4718                         spa_load_spares(spa);
4719                         spa->spa_spares.sav_sync = B_TRUE;
4720                 } else {
4721                         error = EBUSY;
4722                 }
4723         } else if (spa->spa_l2cache.sav_vdevs != NULL &&
4724             nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
4725             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
4726             (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
4727                 /*
4728                  * Cache devices can always be removed.
4729                  */
4730                 spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
4731                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
4732                 spa_load_l2cache(spa);
4733                 spa->spa_l2cache.sav_sync = B_TRUE;
4734         } else if (vd != NULL && vd->vdev_islog) {
4735                 ASSERT(!locked);
4736                 ASSERT(vd == vd->vdev_top);
4737 
4738                 /*
4739                  * XXX - Once we have bp-rewrite this should
4740                  * become the common case.
4741                  */
4742 
4743                 mg = vd->vdev_mg;
4744 
4745                 /*
4746                  * Stop allocating from this vdev.
4747                  */
4748                 metaslab_group_passivate(mg);
4749 
4750                 /*
4751                  * Wait for the youngest allocations and frees to sync,
4752                  * and then wait for the deferral of those frees to finish.
4753                  */
4754                 spa_vdev_config_exit(spa, NULL,
4755                     txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
4756 
4757                 /*
4758                  * Attempt to evacuate the vdev.
4759                  */
4760                 error = spa_vdev_remove_evacuate(spa, vd);
4761 
4762                 txg = spa_vdev_config_enter(spa);
4763 
4764                 /*
4765                  * If we couldn't evacuate the vdev, unwind.
4766                  */
4767                 if (error) {
4768                         metaslab_group_activate(mg);
4769                         return (spa_vdev_exit(spa, NULL, txg, error));
4770                 }
4771 
4772                 /*
4773                  * Clean up the vdev namespace.
4774                  */
4775                 spa_vdev_remove_from_namespace(spa, vd);
4776 
4777         } else if (vd != NULL) {
4778                 /*
4779                  * Normal vdevs cannot be removed (yet).
4780                  */
4781                 error = ENOTSUP;
4782         } else {
4783                 /*
4784                  * There is no vdev of any kind with the specified guid.
4785                  */
4786                 error = ENOENT;
4787         }
4788 
4789         if (!locked)
4790                 return (spa_vdev_exit(spa, NULL, txg, error));
4791 
4792         return (error);
4793 }
4794 
4795 /*
4796  * Find any device that's done replacing, or a vdev marked 'unspare' that's
4797  * current spared, so we can detach it.
4798  */
4799 static vdev_t *
4800 spa_vdev_resilver_done_hunt(vdev_t *vd)
4801 {
4802         vdev_t *newvd, *oldvd;
4803 
4804         for (int c = 0; c < vd->vdev_children; c++) {
4805                 oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
4806                 if (oldvd != NULL)
4807                         return (oldvd);
4808         }
4809 
4810         /*
4811          * Check for a completed replacement.  We always consider the first
4812          * vdev in the list to be the oldest vdev, and the last one to be
4813          * the newest (see spa_vdev_attach() for how that works).  In
4814          * the case where the newest vdev is faulted, we will not automatically
4815          * remove it after a resilver completes.  This is OK as it will require
4816          * user intervention to determine which disk the admin wishes to keep.
4817          */
4818         if (vd->vdev_ops == &vdev_replacing_ops) {
4819                 ASSERT(vd->vdev_children > 1);
4820 
4821                 newvd = vd->vdev_child[vd->vdev_children - 1];
4822                 oldvd = vd->vdev_child[0];
4823 
4824                 if (vdev_dtl_empty(newvd, DTL_MISSING) &&
4825                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
4826                     !vdev_dtl_required(oldvd))
4827                         return (oldvd);
4828         }
4829 
4830         /*
4831          * Check for a completed resilver with the 'unspare' flag set.
4832          */
4833         if (vd->vdev_ops == &vdev_spare_ops) {
4834                 vdev_t *first = vd->vdev_child[0];
4835                 vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
4836 
4837                 if (last->vdev_unspare) {
4838                         oldvd = first;
4839                         newvd = last;
4840                 } else if (first->vdev_unspare) {
4841                         oldvd = last;
4842                         newvd = first;
4843                 } else {
4844                         oldvd = NULL;
4845                 }
4846 
4847                 if (oldvd != NULL &&
4848                     vdev_dtl_empty(newvd, DTL_MISSING) &&
4849                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
4850                     !vdev_dtl_required(oldvd))
4851                         return (oldvd);
4852 
4853                 /*
4854                  * If there are more than two spares attached to a disk,
4855                  * and those spares are not required, then we want to
4856                  * attempt to free them up now so that they can be used
4857                  * by other pools.  Once we're back down to a single
4858                  * disk+spare, we stop removing them.
4859                  */
4860                 if (vd->vdev_children > 2) {
4861                         newvd = vd->vdev_child[1];
4862 
4863                         if (newvd->vdev_isspare && last->vdev_isspare &&
4864                             vdev_dtl_empty(last, DTL_MISSING) &&
4865                             vdev_dtl_empty(last, DTL_OUTAGE) &&
4866                             !vdev_dtl_required(newvd))
4867                                 return (newvd);
4868                 }
4869         }
4870 
4871         return (NULL);
4872 }
4873 
4874 static void
4875 spa_vdev_resilver_done(spa_t *spa)
4876 {
4877         vdev_t *vd, *pvd, *ppvd;
4878         uint64_t guid, sguid, pguid, ppguid;
4879 
4880         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4881 
4882         while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
4883                 pvd = vd->vdev_parent;
4884                 ppvd = pvd->vdev_parent;
4885                 guid = vd->vdev_guid;
4886                 pguid = pvd->vdev_guid;
4887                 ppguid = ppvd->vdev_guid;
4888                 sguid = 0;
4889                 /*
4890                  * If we have just finished replacing a hot spared device, then
4891                  * we need to detach the parent's first child (the original hot
4892                  * spare) as well.
4893                  */
4894                 if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
4895                     ppvd->vdev_children == 2) {
4896                         ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
4897                         sguid = ppvd->vdev_child[1]->vdev_guid;
4898                 }
4899                 spa_config_exit(spa, SCL_ALL, FTAG);
4900                 if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
4901                         return;
4902                 if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
4903                         return;
4904                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4905         }
4906 
4907         spa_config_exit(spa, SCL_ALL, FTAG);
4908 }
4909 
4910 /*
4911  * Update the stored path or FRU for this vdev.
4912  */
4913 int
4914 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
4915     boolean_t ispath)
4916 {
4917         vdev_t *vd;
4918         boolean_t sync = B_FALSE;
4919 
4920         ASSERT(spa_writeable(spa));
4921 
4922         spa_vdev_state_enter(spa, SCL_ALL);
4923 
4924         if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
4925                 return (spa_vdev_state_exit(spa, NULL, ENOENT));
4926 
4927         if (!vd->vdev_ops->vdev_op_leaf)
4928                 return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
4929 
4930         if (ispath) {
4931                 if (strcmp(value, vd->vdev_path) != 0) {
4932                         spa_strfree(vd->vdev_path);
4933                         vd->vdev_path = spa_strdup(value);
4934                         sync = B_TRUE;
4935                 }
4936         } else {
4937                 if (vd->vdev_fru == NULL) {
4938                         vd->vdev_fru = spa_strdup(value);
4939                         sync = B_TRUE;
4940                 } else if (strcmp(value, vd->vdev_fru) != 0) {
4941                         spa_strfree(vd->vdev_fru);
4942                         vd->vdev_fru = spa_strdup(value);
4943                         sync = B_TRUE;
4944                 }
4945         }
4946 
4947         return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
4948 }
4949 
4950 int
4951 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
4952 {
4953         return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
4954 }
4955 
4956 int
4957 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
4958 {
4959         return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
4960 }
4961 
4962 /*
4963  * ==========================================================================
4964  * SPA Scanning
4965  * ==========================================================================
4966  */
4967 
4968 int
4969 spa_scan_stop(spa_t *spa)
4970 {
4971         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
4972         if (dsl_scan_resilvering(spa->spa_dsl_pool))
4973                 return (EBUSY);
4974         return (dsl_scan_cancel(spa->spa_dsl_pool));
4975 }
4976 
4977 int
4978 spa_scan(spa_t *spa, pool_scan_func_t func)
4979 {
4980         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
4981 
4982         if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
4983                 return (ENOTSUP);
4984 
4985         /*
4986          * If a resilver was requested, but there is no DTL on a
4987          * writeable leaf device, we have nothing to do.
4988          */
4989         if (func == POOL_SCAN_RESILVER &&
4990             !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
4991                 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
4992                 return (0);
4993         }
4994 
4995         return (dsl_scan(spa->spa_dsl_pool, func));
4996 }
4997 
4998 /*
4999  * ==========================================================================
5000  * SPA async task processing
5001  * ==========================================================================
5002  */
5003 
5004 static void
5005 spa_async_remove(spa_t *spa, vdev_t *vd)
5006 {
5007         if (vd->vdev_remove_wanted) {
5008                 vd->vdev_remove_wanted = B_FALSE;
5009                 vd->vdev_delayed_close = B_FALSE;
5010                 vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
5011 
5012                 /*
5013                  * We want to clear the stats, but we don't want to do a full
5014                  * vdev_clear() as that will cause us to throw away
5015                  * degraded/faulted state as well as attempt to reopen the
5016                  * device, all of which is a waste.
5017                  */
5018                 vd->vdev_stat.vs_read_errors = 0;
5019                 vd->vdev_stat.vs_write_errors = 0;
5020                 vd->vdev_stat.vs_checksum_errors = 0;
5021 
5022                 vdev_state_dirty(vd->vdev_top);
5023         }
5024 
5025         for (int c = 0; c < vd->vdev_children; c++)
5026                 spa_async_remove(spa, vd->vdev_child[c]);
5027 }
5028 
5029 static void
5030 spa_async_probe(spa_t *spa, vdev_t *vd)
5031 {
5032         if (vd->vdev_probe_wanted) {
5033                 vd->vdev_probe_wanted = B_FALSE;
5034                 vdev_reopen(vd);        /* vdev_open() does the actual probe */
5035         }
5036 
5037         for (int c = 0; c < vd->vdev_children; c++)
5038                 spa_async_probe(spa, vd->vdev_child[c]);
5039 }
5040 
5041 static void
5042 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
5043 {
5044         sysevent_id_t eid;
5045         nvlist_t *attr;
5046         char *physpath;
5047 
5048         if (!spa->spa_autoexpand)
5049                 return;
5050 
5051         for (int c = 0; c < vd->vdev_children; c++) {
5052                 vdev_t *cvd = vd->vdev_child[c];
5053                 spa_async_autoexpand(spa, cvd);
5054         }
5055 
5056         if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
5057                 return;
5058 
5059         physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
5060         (void) snprintf(physpath, MAXPATHLEN, "/devices%s", vd->vdev_physpath);
5061 
5062         VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5063         VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
5064 
5065         (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
5066             ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
5067 
5068         nvlist_free(attr);
5069         kmem_free(physpath, MAXPATHLEN);
5070 }
5071 
5072 static void
5073 spa_async_thread(spa_t *spa)
5074 {
5075         int tasks;
5076 
5077         ASSERT(spa->spa_sync_on);
5078 
5079         mutex_enter(&spa->spa_async_lock);
5080         tasks = spa->spa_async_tasks;
5081         spa->spa_async_tasks = 0;
5082         mutex_exit(&spa->spa_async_lock);
5083 
5084         /*
5085          * See if the config needs to be updated.
5086          */
5087         if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
5088                 uint64_t old_space, new_space;
5089 
5090                 mutex_enter(&spa_namespace_lock);
5091                 old_space = metaslab_class_get_space(spa_normal_class(spa));
5092                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
5093                 new_space = metaslab_class_get_space(spa_normal_class(spa));
5094                 mutex_exit(&spa_namespace_lock);
5095 
5096                 /*
5097                  * If the pool grew as a result of the config update,
5098                  * then log an internal history event.
5099                  */
5100                 if (new_space != old_space) {
5101                         spa_history_log_internal(LOG_POOL_VDEV_ONLINE,
5102                             spa, NULL,
5103                             "pool '%s' size: %llu(+%llu)",
5104                             spa_name(spa), new_space, new_space - old_space);
5105                 }
5106         }
5107 
5108         /*
5109          * See if any devices need to be marked REMOVED.
5110          */
5111         if (tasks & SPA_ASYNC_REMOVE) {
5112                 spa_vdev_state_enter(spa, SCL_NONE);
5113                 spa_async_remove(spa, spa->spa_root_vdev);
5114                 for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
5115                         spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
5116                 for (int i = 0; i < spa->spa_spares.sav_count; i++)
5117                         spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
5118                 (void) spa_vdev_state_exit(spa, NULL, 0);
5119         }
5120 
5121         if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
5122                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5123                 spa_async_autoexpand(spa, spa->spa_root_vdev);
5124                 spa_config_exit(spa, SCL_CONFIG, FTAG);
5125         }
5126 
5127         /*
5128          * See if any devices need to be probed.
5129          */
5130         if (tasks & SPA_ASYNC_PROBE) {
5131                 spa_vdev_state_enter(spa, SCL_NONE);
5132                 spa_async_probe(spa, spa->spa_root_vdev);
5133                 (void) spa_vdev_state_exit(spa, NULL, 0);
5134         }
5135 
5136         /*
5137          * If any devices are done replacing, detach them.
5138          */
5139         if (tasks & SPA_ASYNC_RESILVER_DONE)
5140                 spa_vdev_resilver_done(spa);
5141 
5142         /*
5143          * Kick off a resilver.
5144          */
5145         if (tasks & SPA_ASYNC_RESILVER)
5146                 dsl_resilver_restart(spa->spa_dsl_pool, 0);
5147 
5148         /*
5149          * Let the world know that we're done.
5150          */
5151         mutex_enter(&spa->spa_async_lock);
5152         spa->spa_async_thread = NULL;
5153         cv_broadcast(&spa->spa_async_cv);
5154         mutex_exit(&spa->spa_async_lock);
5155         thread_exit();
5156 }
5157 
5158 void
5159 spa_async_suspend(spa_t *spa)
5160 {
5161         mutex_enter(&spa->spa_async_lock);
5162         spa->spa_async_suspended++;
5163         while (spa->spa_async_thread != NULL)
5164                 cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
5165         mutex_exit(&spa->spa_async_lock);
5166 }
5167 
5168 void
5169 spa_async_resume(spa_t *spa)
5170 {
5171         mutex_enter(&spa->spa_async_lock);
5172         ASSERT(spa->spa_async_suspended != 0);
5173         spa->spa_async_suspended--;
5174         mutex_exit(&spa->spa_async_lock);
5175 }
5176 
5177 static void
5178 spa_async_dispatch(spa_t *spa)
5179 {
5180         mutex_enter(&spa->spa_async_lock);
5181         if (spa->spa_async_tasks && !spa->spa_async_suspended &&
5182             spa->spa_async_thread == NULL &&
5183             rootdir != NULL && !vn_is_readonly(rootdir))
5184                 spa->spa_async_thread = thread_create(NULL, 0,
5185                     spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
5186         mutex_exit(&spa->spa_async_lock);
5187 }
5188 
5189 void
5190 spa_async_request(spa_t *spa, int task)
5191 {
5192         zfs_dbgmsg("spa=%s async request task=%u", spa->spa_name, task);
5193         mutex_enter(&spa->spa_async_lock);
5194         spa->spa_async_tasks |= task;
5195         mutex_exit(&spa->spa_async_lock);
5196 }
5197 
5198 /*
5199  * ==========================================================================
5200  * SPA syncing routines
5201  * ==========================================================================
5202  */
5203 
5204 static int
5205 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5206 {
5207         bpobj_t *bpo = arg;
5208         bpobj_enqueue(bpo, bp, tx);
5209         return (0);
5210 }
5211 
5212 static int
5213 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5214 {
5215         zio_t *zio = arg;
5216 
5217         zio_nowait(zio_free_sync(zio, zio->io_spa, dmu_tx_get_txg(tx), bp,
5218             zio->io_flags));
5219         return (0);
5220 }
5221 
5222 static void
5223 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
5224 {
5225         char *packed = NULL;
5226         size_t bufsize;
5227         size_t nvsize = 0;
5228         dmu_buf_t *db;
5229 
5230         VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
5231 
5232         /*
5233          * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
5234          * information.  This avoids the dbuf_will_dirty() path and
5235          * saves us a pre-read to get data we don't actually care about.
5236          */
5237         bufsize = P2ROUNDUP(nvsize, SPA_CONFIG_BLOCKSIZE);
5238         packed = kmem_alloc(bufsize, KM_SLEEP);
5239 
5240         VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
5241             KM_SLEEP) == 0);
5242         bzero(packed + nvsize, bufsize - nvsize);
5243 
5244         dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
5245 
5246         kmem_free(packed, bufsize);
5247 
5248         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
5249         dmu_buf_will_dirty(db, tx);
5250         *(uint64_t *)db->db_data = nvsize;
5251         dmu_buf_rele(db, FTAG);
5252 }
5253 
5254 static void
5255 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
5256     const char *config, const char *entry)
5257 {
5258         nvlist_t *nvroot;
5259         nvlist_t **list;
5260         int i;
5261 
5262         if (!sav->sav_sync)
5263                 return;
5264 
5265         /*
5266          * Update the MOS nvlist describing the list of available devices.
5267          * spa_validate_aux() will have already made sure this nvlist is
5268          * valid and the vdevs are labeled appropriately.
5269          */
5270         if (sav->sav_object == 0) {
5271                 sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
5272                     DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
5273                     sizeof (uint64_t), tx);
5274                 VERIFY(zap_update(spa->spa_meta_objset,
5275                     DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
5276                     &sav->sav_object, tx) == 0);
5277         }
5278 
5279         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5280         if (sav->sav_count == 0) {
5281                 VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
5282         } else {
5283                 list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
5284                 for (i = 0; i < sav->sav_count; i++)
5285                         list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
5286                             B_FALSE, VDEV_CONFIG_L2CACHE);
5287                 VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
5288                     sav->sav_count) == 0);
5289                 for (i = 0; i < sav->sav_count; i++)
5290                         nvlist_free(list[i]);
5291                 kmem_free(list, sav->sav_count * sizeof (void *));
5292         }
5293 
5294         spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
5295         nvlist_free(nvroot);
5296 
5297         sav->sav_sync = B_FALSE;
5298 }
5299 
5300 static void
5301 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
5302 {
5303         nvlist_t *config;
5304 
5305         if (list_is_empty(&spa->spa_config_dirty_list))
5306                 return;
5307 
5308         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5309 
5310         config = spa_config_generate(spa, spa->spa_root_vdev,
5311             dmu_tx_get_txg(tx), B_FALSE);
5312 
5313         spa_config_exit(spa, SCL_STATE, FTAG);
5314 
5315         if (spa->spa_config_syncing)
5316                 nvlist_free(spa->spa_config_syncing);
5317         spa->spa_config_syncing = config;
5318 
5319         spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
5320 }
5321 
5322 /*
5323  * Set zpool properties.
5324  */
5325 static void
5326 spa_sync_props(void *arg1, void *arg2, dmu_tx_t *tx)
5327 {
5328         spa_t *spa = arg1;
5329         objset_t *mos = spa->spa_meta_objset;
5330         nvlist_t *nvp = arg2;
5331         nvpair_t *elem;
5332         uint64_t intval;
5333         char *strval;
5334         zpool_prop_t prop;
5335         const char *propname;
5336         zprop_type_t proptype;
5337 
5338         mutex_enter(&spa->spa_props_lock);
5339 
5340         elem = NULL;
5341         while ((elem = nvlist_next_nvpair(nvp, elem))) {
5342                 switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
5343                 case ZPOOL_PROP_VERSION:
5344                         /*
5345                          * Only set version for non-zpool-creation cases
5346                          * (set/import). spa_create() needs special care
5347                          * for version setting.
5348                          */
5349                         if (tx->tx_txg != TXG_INITIAL) {
5350                                 VERIFY(nvpair_value_uint64(elem,
5351                                     &intval) == 0);
5352                                 ASSERT(intval <= SPA_VERSION);
5353                                 ASSERT(intval >= spa_version(spa));
5354                                 spa->spa_uberblock.ub_version = intval;
5355                                 vdev_config_dirty(spa->spa_root_vdev);
5356                         }
5357                         break;
5358 
5359                 case ZPOOL_PROP_ALTROOT:
5360                         /*
5361                          * 'altroot' is a non-persistent property. It should
5362                          * have been set temporarily at creation or import time.
5363                          */
5364                         ASSERT(spa->spa_root != NULL);
5365                         break;
5366 
5367                 case ZPOOL_PROP_READONLY:
5368                 case ZPOOL_PROP_CACHEFILE:
5369                         /*
5370                          * 'readonly' and 'cachefile' are also non-persisitent
5371                          * properties.
5372                          */
5373                         break;
5374                 default:
5375                         /*
5376                          * Set pool property values in the poolprops mos object.
5377                          */
5378                         if (spa->spa_pool_props_object == 0) {
5379                                 VERIFY((spa->spa_pool_props_object =
5380                                     zap_create(mos, DMU_OT_POOL_PROPS,
5381                                     DMU_OT_NONE, 0, tx)) > 0);
5382 
5383                                 VERIFY(zap_update(mos,
5384                                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
5385                                     8, 1, &spa->spa_pool_props_object, tx)
5386                                     == 0);
5387                         }
5388 
5389                         /* normalize the property name */
5390                         propname = zpool_prop_to_name(prop);
5391                         proptype = zpool_prop_get_type(prop);
5392 
5393                         if (nvpair_type(elem) == DATA_TYPE_STRING) {
5394                                 ASSERT(proptype == PROP_TYPE_STRING);
5395                                 VERIFY(nvpair_value_string(elem, &strval) == 0);
5396                                 VERIFY(zap_update(mos,
5397                                     spa->spa_pool_props_object, propname,
5398                                     1, strlen(strval) + 1, strval, tx) == 0);
5399 
5400                         } else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
5401                                 VERIFY(nvpair_value_uint64(elem, &intval) == 0);
5402 
5403                                 if (proptype == PROP_TYPE_INDEX) {
5404                                         const char *unused;
5405                                         VERIFY(zpool_prop_index_to_string(
5406                                             prop, intval, &unused) == 0);
5407                                 }
5408                                 VERIFY(zap_update(mos,
5409                                     spa->spa_pool_props_object, propname,
5410                                     8, 1, &intval, tx) == 0);
5411                         } else {
5412                                 ASSERT(0); /* not allowed */
5413                         }
5414 
5415                         switch (prop) {
5416                         case ZPOOL_PROP_DELEGATION:
5417                                 spa->spa_delegation = intval;
5418                                 break;
5419                         case ZPOOL_PROP_BOOTFS:
5420                                 spa->spa_bootfs = intval;
5421                                 break;
5422                         case ZPOOL_PROP_FAILUREMODE:
5423                                 spa->spa_failmode = intval;
5424                                 break;
5425                         case ZPOOL_PROP_AUTOEXPAND:
5426                                 spa->spa_autoexpand = intval;
5427                                 if (tx->tx_txg != TXG_INITIAL)
5428                                         spa_async_request(spa,
5429                                             SPA_ASYNC_AUTOEXPAND);
5430                                 break;
5431                         case ZPOOL_PROP_DEDUPDITTO:
5432                                 spa->spa_dedup_ditto = intval;
5433                                 break;
5434                         default:
5435                                 break;
5436                         }
5437                 }
5438 
5439                 /* log internal history if this is not a zpool create */
5440                 if (spa_version(spa) >= SPA_VERSION_ZPOOL_HISTORY &&
5441                     tx->tx_txg != TXG_INITIAL) {
5442                         spa_history_log_internal(LOG_POOL_PROPSET,
5443                             spa, tx, "%s %lld %s",
5444                             nvpair_name(elem), intval, spa_name(spa));
5445                 }
5446         }
5447 
5448         mutex_exit(&spa->spa_props_lock);
5449 }
5450 
5451 /*
5452  * Perform one-time upgrade on-disk changes.  spa_version() does not
5453  * reflect the new version this txg, so there must be no changes this
5454  * txg to anything that the upgrade code depends on after it executes.
5455  * Therefore this must be called after dsl_pool_sync() does the sync
5456  * tasks.
5457  */
5458 static void
5459 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
5460 {
5461         dsl_pool_t *dp = spa->spa_dsl_pool;
5462 
5463         ASSERT(spa->spa_sync_pass == 1);
5464 
5465         if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
5466             spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
5467                 dsl_pool_create_origin(dp, tx);
5468 
5469                 /* Keeping the origin open increases spa_minref */
5470                 spa->spa_minref += 3;
5471         }
5472 
5473         if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
5474             spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
5475                 dsl_pool_upgrade_clones(dp, tx);
5476         }
5477 
5478         if (spa->spa_ubsync.ub_version < SPA_VERSION_DIR_CLONES &&
5479             spa->spa_uberblock.ub_version >= SPA_VERSION_DIR_CLONES) {
5480                 dsl_pool_upgrade_dir_clones(dp, tx);
5481 
5482                 /* Keeping the freedir open increases spa_minref */
5483                 spa->spa_minref += 3;
5484         }
5485 }
5486 
5487 /*
5488  * Sync the specified transaction group.  New blocks may be dirtied as
5489  * part of the process, so we iterate until it converges.
5490  */
5491 void
5492 spa_sync(spa_t *spa, uint64_t txg)
5493 {
5494         dsl_pool_t *dp = spa->spa_dsl_pool;
5495         objset_t *mos = spa->spa_meta_objset;
5496         bpobj_t *defer_bpo = &spa->spa_deferred_bpobj;
5497         bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
5498         vdev_t *rvd = spa->spa_root_vdev;
5499         vdev_t *vd;
5500         dmu_tx_t *tx;
5501         int error;
5502 
5503         VERIFY(spa_writeable(spa));
5504 
5505         /*
5506          * Lock out configuration changes.
5507          */
5508         spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5509 
5510         spa->spa_syncing_txg = txg;
5511         spa->spa_sync_pass = 0;
5512 
5513         /*
5514          * If there are any pending vdev state changes, convert them
5515          * into config changes that go out with this transaction group.
5516          */
5517         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5518         while (list_head(&spa->spa_state_dirty_list) != NULL) {
5519                 /*
5520                  * We need the write lock here because, for aux vdevs,
5521                  * calling vdev_config_dirty() modifies sav_config.
5522                  * This is ugly and will become unnecessary when we
5523                  * eliminate the aux vdev wart by integrating all vdevs
5524                  * into the root vdev tree.
5525                  */
5526                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
5527                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
5528                 while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
5529                         vdev_state_clean(vd);
5530                         vdev_config_dirty(vd);
5531                 }
5532                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
5533                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
5534         }
5535         spa_config_exit(spa, SCL_STATE, FTAG);
5536 
5537         tx = dmu_tx_create_assigned(dp, txg);
5538 
5539         /*
5540          * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
5541          * set spa_deflate if we have no raid-z vdevs.
5542          */
5543         if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
5544             spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
5545                 int i;
5546 
5547                 for (i = 0; i < rvd->vdev_children; i++) {
5548                         vd = rvd->vdev_child[i];
5549                         if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
5550                                 break;
5551                 }
5552                 if (i == rvd->vdev_children) {
5553                         spa->spa_deflate = TRUE;
5554                         VERIFY(0 == zap_add(spa->spa_meta_objset,
5555                             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
5556                             sizeof (uint64_t), 1, &spa->spa_deflate, tx));
5557                 }
5558         }
5559 
5560         /*
5561          * If anything has changed in this txg, or if someone is waiting
5562          * for this txg to sync (eg, spa_vdev_remove()), push the
5563          * deferred frees from the previous txg.  If not, leave them
5564          * alone so that we don't generate work on an otherwise idle
5565          * system.
5566          */
5567         if (!txg_list_empty(&dp->dp_dirty_datasets, txg) ||
5568             !txg_list_empty(&dp->dp_dirty_dirs, txg) ||
5569             !txg_list_empty(&dp->dp_sync_tasks, txg) ||
5570             ((dsl_scan_active(dp->dp_scan) ||
5571             txg_sync_waiting(dp)) && !spa_shutting_down(spa))) {
5572                 zio_t *zio = zio_root(spa, NULL, NULL, 0);
5573                 VERIFY3U(bpobj_iterate(defer_bpo,
5574                     spa_free_sync_cb, zio, tx), ==, 0);
5575                 VERIFY3U(zio_wait(zio), ==, 0);
5576         }
5577 
5578         /*
5579          * Iterate to convergence.
5580          */
5581         do {
5582                 int pass = ++spa->spa_sync_pass;
5583 
5584                 spa_sync_config_object(spa, tx);
5585                 spa_sync_aux_dev(spa, &spa->spa_spares, tx,
5586                     ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
5587                 spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
5588                     ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
5589                 spa_errlog_sync(spa, txg);
5590                 dsl_pool_sync(dp, txg);
5591 
5592                 if (pass <= SYNC_PASS_DEFERRED_FREE) {
5593                         zio_t *zio = zio_root(spa, NULL, NULL, 0);
5594                         bplist_iterate(free_bpl, spa_free_sync_cb,
5595                             zio, tx);
5596                         VERIFY(zio_wait(zio) == 0);
5597                 } else {
5598                         bplist_iterate(free_bpl, bpobj_enqueue_cb,
5599                             defer_bpo, tx);
5600                 }
5601 
5602                 ddt_sync(spa, txg);
5603                 dsl_scan_sync(dp, tx);
5604 
5605                 while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
5606                         vdev_sync(vd, txg);
5607 
5608                 if (pass == 1)
5609                         spa_sync_upgrades(spa, tx);
5610 
5611         } while (dmu_objset_is_dirty(mos, txg));
5612 
5613         /*
5614          * Rewrite the vdev configuration (which includes the uberblock)
5615          * to commit the transaction group.
5616          *
5617          * If there are no dirty vdevs, we sync the uberblock to a few
5618          * random top-level vdevs that are known to be visible in the
5619          * config cache (see spa_vdev_add() for a complete description).
5620          * If there *are* dirty vdevs, sync the uberblock to all vdevs.
5621          */
5622         for (;;) {
5623                 /*
5624                  * We hold SCL_STATE to prevent vdev open/close/etc.
5625                  * while we're attempting to write the vdev labels.
5626                  */
5627                 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5628 
5629                 if (list_is_empty(&spa->spa_config_dirty_list)) {
5630                         vdev_t *svd[SPA_DVAS_PER_BP];
5631                         int svdcount = 0;
5632                         int children = rvd->vdev_children;
5633                         int c0 = spa_get_random(children);
5634 
5635                         for (int c = 0; c < children; c++) {
5636                                 vd = rvd->vdev_child[(c0 + c) % children];
5637                                 if (vd->vdev_ms_array == 0 || vd->vdev_islog)
5638                                         continue;
5639                                 svd[svdcount++] = vd;
5640                                 if (svdcount == SPA_DVAS_PER_BP)
5641                                         break;
5642                         }
5643                         error = vdev_config_sync(svd, svdcount, txg, B_FALSE);
5644                         if (error != 0)
5645                                 error = vdev_config_sync(svd, svdcount, txg,
5646                                     B_TRUE);
5647                 } else {
5648                         error = vdev_config_sync(rvd->vdev_child,
5649                             rvd->vdev_children, txg, B_FALSE);
5650                         if (error != 0)
5651                                 error = vdev_config_sync(rvd->vdev_child,
5652                                     rvd->vdev_children, txg, B_TRUE);
5653                 }
5654 
5655                 spa_config_exit(spa, SCL_STATE, FTAG);
5656 
5657                 if (error == 0)
5658                         break;
5659                 zio_suspend(spa, NULL);
5660                 zio_resume_wait(spa);
5661         }
5662         dmu_tx_commit(tx);
5663 
5664         /*
5665          * Clear the dirty config list.
5666          */
5667         while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
5668                 vdev_config_clean(vd);
5669 
5670         /*
5671          * Now that the new config has synced transactionally,
5672          * let it become visible to the config cache.
5673          */
5674         if (spa->spa_config_syncing != NULL) {
5675                 spa_config_set(spa, spa->spa_config_syncing);
5676                 spa->spa_config_txg = txg;
5677                 spa->spa_config_syncing = NULL;
5678         }
5679 
5680         spa->spa_ubsync = spa->spa_uberblock;
5681 
5682         dsl_pool_sync_done(dp, txg);
5683 
5684         /*
5685          * Update usable space statistics.
5686          */
5687         while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
5688                 vdev_sync_done(vd, txg);
5689 
5690         spa_update_dspace(spa);
5691 
5692         /*
5693          * It had better be the case that we didn't dirty anything
5694          * since vdev_config_sync().
5695          */
5696         ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
5697         ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
5698         ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
5699 
5700         spa->spa_sync_pass = 0;
5701 
5702         spa_config_exit(spa, SCL_CONFIG, FTAG);
5703 
5704         spa_handle_ignored_writes(spa);
5705 
5706         /*
5707          * If any async tasks have been requested, kick them off.
5708          */
5709         spa_async_dispatch(spa);
5710 }
5711 
5712 /*
5713  * Sync all pools.  We don't want to hold the namespace lock across these
5714  * operations, so we take a reference on the spa_t and drop the lock during the
5715  * sync.
5716  */
5717 void
5718 spa_sync_allpools(void)
5719 {
5720         spa_t *spa = NULL;
5721         mutex_enter(&spa_namespace_lock);
5722         while ((spa = spa_next(spa)) != NULL) {
5723                 if (spa_state(spa) != POOL_STATE_ACTIVE ||
5724                     !spa_writeable(spa) || spa_suspended(spa))
5725                         continue;
5726                 spa_open_ref(spa, FTAG);
5727                 mutex_exit(&spa_namespace_lock);
5728                 txg_wait_synced(spa_get_dsl(spa), 0);
5729                 mutex_enter(&spa_namespace_lock);
5730                 spa_close(spa, FTAG);
5731         }
5732         mutex_exit(&spa_namespace_lock);
5733 }
5734 
5735 /*
5736  * ==========================================================================
5737  * Miscellaneous routines
5738  * ==========================================================================
5739  */
5740 
5741 /*
5742  * Remove all pools in the system.
5743  */
5744 void
5745 spa_evict_all(void)
5746 {
5747         spa_t *spa;
5748 
5749         /*
5750          * Remove all cached state.  All pools should be closed now,
5751          * so every spa in the AVL tree should be unreferenced.
5752          */
5753         mutex_enter(&spa_namespace_lock);
5754         while ((spa = spa_next(NULL)) != NULL) {
5755                 /*
5756                  * Stop async tasks.  The async thread may need to detach
5757                  * a device that's been replaced, which requires grabbing
5758                  * spa_namespace_lock, so we must drop it here.
5759                  */
5760                 spa_open_ref(spa, FTAG);
5761                 mutex_exit(&spa_namespace_lock);
5762                 spa_async_suspend(spa);
5763                 mutex_enter(&spa_namespace_lock);
5764                 spa_close(spa, FTAG);
5765 
5766                 if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
5767                         spa_unload(spa);
5768                         spa_deactivate(spa);
5769                 }
5770                 spa_remove(spa);
5771         }
5772         mutex_exit(&spa_namespace_lock);
5773 }
5774 
5775 vdev_t *
5776 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
5777 {
5778         vdev_t *vd;
5779         int i;
5780 
5781         if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
5782                 return (vd);
5783 
5784         if (aux) {
5785                 for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
5786                         vd = spa->spa_l2cache.sav_vdevs[i];
5787                         if (vd->vdev_guid == guid)
5788                                 return (vd);
5789                 }
5790 
5791                 for (i = 0; i < spa->spa_spares.sav_count; i++) {
5792                         vd = spa->spa_spares.sav_vdevs[i];
5793                         if (vd->vdev_guid == guid)
5794                                 return (vd);
5795                 }
5796         }
5797 
5798         return (NULL);
5799 }
5800 
5801 void
5802 spa_upgrade(spa_t *spa, uint64_t version)
5803 {
5804         ASSERT(spa_writeable(spa));
5805 
5806         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5807 
5808         /*
5809          * This should only be called for a non-faulted pool, and since a
5810          * future version would result in an unopenable pool, this shouldn't be
5811          * possible.
5812          */
5813         ASSERT(spa->spa_uberblock.ub_version <= SPA_VERSION);
5814         ASSERT(version >= spa->spa_uberblock.ub_version);
5815 
5816         spa->spa_uberblock.ub_version = version;
5817         vdev_config_dirty(spa->spa_root_vdev);
5818 
5819         spa_config_exit(spa, SCL_ALL, FTAG);
5820 
5821         txg_wait_synced(spa_get_dsl(spa), 0);
5822 }
5823 
5824 boolean_t
5825 spa_has_spare(spa_t *spa, uint64_t guid)
5826 {
5827         int i;
5828         uint64_t spareguid;
5829         spa_aux_vdev_t *sav = &spa->spa_spares;
5830 
5831         for (i = 0; i < sav->sav_count; i++)
5832                 if (sav->sav_vdevs[i]->vdev_guid == guid)
5833                         return (B_TRUE);
5834 
5835         for (i = 0; i < sav->sav_npending; i++) {
5836                 if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
5837                     &spareguid) == 0 && spareguid == guid)
5838                         return (B_TRUE);
5839         }
5840 
5841         return (B_FALSE);
5842 }
5843 
5844 /*
5845  * Check if a pool has an active shared spare device.
5846  * Note: reference count of an active spare is 2, as a spare and as a replace
5847  */
5848 static boolean_t
5849 spa_has_active_shared_spare(spa_t *spa)
5850 {
5851         int i, refcnt;
5852         uint64_t pool;
5853         spa_aux_vdev_t *sav = &spa->spa_spares;
5854 
5855         for (i = 0; i < sav->sav_count; i++) {
5856                 if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
5857                     &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
5858                     refcnt > 2)
5859                         return (B_TRUE);
5860         }
5861 
5862         return (B_FALSE);
5863 }
5864 
5865 /*
5866  * Post a sysevent corresponding to the given event.  The 'name' must be one of
5867  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
5868  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
5869  * in the userland libzpool, as we don't want consumers to misinterpret ztest
5870  * or zdb as real changes.
5871  */
5872 void
5873 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
5874 {
5875 #ifdef _KERNEL
5876         sysevent_t              *ev;
5877         sysevent_attr_list_t    *attr = NULL;
5878         sysevent_value_t        value;
5879         sysevent_id_t           eid;
5880 
5881         ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
5882             SE_SLEEP);
5883 
5884         value.value_type = SE_DATA_TYPE_STRING;
5885         value.value.sv_string = spa_name(spa);
5886         if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
5887                 goto done;
5888 
5889         value.value_type = SE_DATA_TYPE_UINT64;
5890         value.value.sv_uint64 = spa_guid(spa);
5891         if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
5892                 goto done;
5893 
5894         if (vd) {
5895                 value.value_type = SE_DATA_TYPE_UINT64;
5896                 value.value.sv_uint64 = vd->vdev_guid;
5897                 if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
5898                     SE_SLEEP) != 0)
5899                         goto done;
5900 
5901                 if (vd->vdev_path) {
5902                         value.value_type = SE_DATA_TYPE_STRING;
5903                         value.value.sv_string = vd->vdev_path;
5904                         if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
5905                             &value, SE_SLEEP) != 0)
5906                                 goto done;
5907                 }
5908         }
5909 
5910         if (sysevent_attach_attributes(ev, attr) != 0)
5911                 goto done;
5912         attr = NULL;
5913 
5914         (void) log_sysevent(ev, SE_SLEEP, &eid);
5915 
5916 done:
5917         if (attr)
5918                 sysevent_free_attr(attr);
5919         sysevent_free(ev);
5920 #endif
5921 }