1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright (c) 2013 by Delphix. All rights reserved.
  25  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
  26  */
  27 
  28 /*
  29  * SPA: Storage Pool Allocator
  30  *
  31  * This file contains all the routines used when modifying on-disk SPA state.
  32  * This includes opening, importing, destroying, exporting a pool, and syncing a
  33  * pool.
  34  */
  35 
  36 #include <sys/zfs_context.h>
  37 #include <sys/fm/fs/zfs.h>
  38 #include <sys/spa_impl.h>
  39 #include <sys/zio.h>
  40 #include <sys/zio_checksum.h>
  41 #include <sys/dmu.h>
  42 #include <sys/dmu_tx.h>
  43 #include <sys/zap.h>
  44 #include <sys/zil.h>
  45 #include <sys/ddt.h>
  46 #include <sys/vdev_impl.h>
  47 #include <sys/metaslab.h>
  48 #include <sys/metaslab_impl.h>
  49 #include <sys/uberblock_impl.h>
  50 #include <sys/txg.h>
  51 #include <sys/avl.h>
  52 #include <sys/dmu_traverse.h>
  53 #include <sys/dmu_objset.h>
  54 #include <sys/unique.h>
  55 #include <sys/dsl_pool.h>
  56 #include <sys/dsl_dataset.h>
  57 #include <sys/dsl_dir.h>
  58 #include <sys/dsl_prop.h>
  59 #include <sys/dsl_synctask.h>
  60 #include <sys/fs/zfs.h>
  61 #include <sys/arc.h>
  62 #include <sys/callb.h>
  63 #include <sys/systeminfo.h>
  64 #include <sys/spa_boot.h>
  65 #include <sys/zfs_ioctl.h>
  66 #include <sys/dsl_scan.h>
  67 #include <sys/zfeature.h>
  68 #include <sys/dsl_destroy.h>
  69 
  70 #ifdef  _KERNEL
  71 #include <sys/bootprops.h>
  72 #include <sys/callb.h>
  73 #include <sys/cpupart.h>
  74 #include <sys/pool.h>
  75 #include <sys/sysdc.h>
  76 #include <sys/zone.h>
  77 #endif  /* _KERNEL */
  78 
  79 #include "zfs_prop.h"
  80 #include "zfs_comutil.h"
  81 
  82 /*
  83  * The interval, in seconds, at which failed configuration cache file writes
  84  * should be retried.
  85  */
  86 static int zfs_ccw_retry_interval = 300;
  87 
  88 typedef enum zti_modes {
  89         ZTI_MODE_FIXED,                 /* value is # of threads (min 1) */
  90         ZTI_MODE_BATCH,                 /* cpu-intensive; value is ignored */
  91         ZTI_MODE_NULL,                  /* don't create a taskq */
  92         ZTI_NMODES
  93 } zti_modes_t;
  94 
  95 #define ZTI_P(n, q)     { ZTI_MODE_FIXED, (n), (q) }
  96 #define ZTI_BATCH       { ZTI_MODE_BATCH, 0, 1 }
  97 #define ZTI_NULL        { ZTI_MODE_NULL, 0, 0 }
  98 
  99 #define ZTI_N(n)        ZTI_P(n, 1)
 100 #define ZTI_ONE         ZTI_N(1)
 101 
 102 typedef struct zio_taskq_info {
 103         zti_modes_t zti_mode;
 104         uint_t zti_value;
 105         uint_t zti_count;
 106 } zio_taskq_info_t;
 107 
 108 static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
 109         "issue", "issue_high", "intr", "intr_high"
 110 };
 111 
 112 /*
 113  * This table defines the taskq settings for each ZFS I/O type. When
 114  * initializing a pool, we use this table to create an appropriately sized
 115  * taskq. Some operations are low volume and therefore have a small, static
 116  * number of threads assigned to their taskqs using the ZTI_N(#) or ZTI_ONE
 117  * macros. Other operations process a large amount of data; the ZTI_BATCH
 118  * macro causes us to create a taskq oriented for throughput. Some operations
 119  * are so high frequency and short-lived that the taskq itself can become a a
 120  * point of lock contention. The ZTI_P(#, #) macro indicates that we need an
 121  * additional degree of parallelism specified by the number of threads per-
 122  * taskq and the number of taskqs; when dispatching an event in this case, the
 123  * particular taskq is chosen at random.
 124  *
 125  * The different taskq priorities are to handle the different contexts (issue
 126  * and interrupt) and then to reserve threads for ZIO_PRIORITY_NOW I/Os that
 127  * need to be handled with minimum delay.
 128  */
 129 const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
 130         /* ISSUE        ISSUE_HIGH      INTR            INTR_HIGH */
 131         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* NULL */
 132         { ZTI_N(8),     ZTI_NULL,       ZTI_BATCH,      ZTI_NULL }, /* READ */
 133         { ZTI_BATCH,    ZTI_N(5),       ZTI_N(8),       ZTI_N(5) }, /* WRITE */
 134         { ZTI_P(12, 8), ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* FREE */
 135         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* CLAIM */
 136         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* IOCTL */
 137 };
 138 
 139 static void spa_sync_version(void *arg, dmu_tx_t *tx);
 140 static void spa_sync_props(void *arg, dmu_tx_t *tx);
 141 static boolean_t spa_has_active_shared_spare(spa_t *spa);
 142 static int spa_load_impl(spa_t *spa, uint64_t, nvlist_t *config,
 143     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
 144     char **ereport);
 145 static void spa_vdev_resilver_done(spa_t *spa);
 146 
 147 uint_t          zio_taskq_batch_pct = 75;       /* 1 thread per cpu in pset */
 148 id_t            zio_taskq_psrset_bind = PS_NONE;
 149 boolean_t       zio_taskq_sysdc = B_TRUE;       /* use SDC scheduling class */
 150 uint_t          zio_taskq_basedc = 80;          /* base duty cycle */
 151 
 152 boolean_t       spa_create_process = B_TRUE;    /* no process ==> no sysdc */
 153 extern int      zfs_sync_pass_deferred_free;
 154 
 155 /*
 156  * This (illegal) pool name is used when temporarily importing a spa_t in order
 157  * to get the vdev stats associated with the imported devices.
 158  */
 159 #define TRYIMPORT_NAME  "$import"
 160 
 161 /*
 162  * ==========================================================================
 163  * SPA properties routines
 164  * ==========================================================================
 165  */
 166 
 167 /*
 168  * Add a (source=src, propname=propval) list to an nvlist.
 169  */
 170 static void
 171 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, char *strval,
 172     uint64_t intval, zprop_source_t src)
 173 {
 174         const char *propname = zpool_prop_to_name(prop);
 175         nvlist_t *propval;
 176 
 177         VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 178         VERIFY(nvlist_add_uint64(propval, ZPROP_SOURCE, src) == 0);
 179 
 180         if (strval != NULL)
 181                 VERIFY(nvlist_add_string(propval, ZPROP_VALUE, strval) == 0);
 182         else
 183                 VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, intval) == 0);
 184 
 185         VERIFY(nvlist_add_nvlist(nvl, propname, propval) == 0);
 186         nvlist_free(propval);
 187 }
 188 
 189 /*
 190  * Get property values from the spa configuration.
 191  */
 192 static void
 193 spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
 194 {
 195         vdev_t *rvd = spa->spa_root_vdev;
 196         dsl_pool_t *pool = spa->spa_dsl_pool;
 197         uint64_t size;
 198         uint64_t alloc;
 199         uint64_t space;
 200         uint64_t cap, version;
 201         zprop_source_t src = ZPROP_SRC_NONE;
 202         spa_config_dirent_t *dp;
 203 
 204         ASSERT(MUTEX_HELD(&spa->spa_props_lock));
 205 
 206         if (rvd != NULL) {
 207                 alloc = metaslab_class_get_alloc(spa_normal_class(spa));
 208                 size = metaslab_class_get_space(spa_normal_class(spa));
 209                 spa_prop_add_list(*nvp, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
 210                 spa_prop_add_list(*nvp, ZPOOL_PROP_SIZE, NULL, size, src);
 211                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALLOCATED, NULL, alloc, src);
 212                 spa_prop_add_list(*nvp, ZPOOL_PROP_FREE, NULL,
 213                     size - alloc, src);
 214 
 215                 space = 0;
 216                 for (int c = 0; c < rvd->vdev_children; c++) {
 217                         vdev_t *tvd = rvd->vdev_child[c];
 218                         space += tvd->vdev_max_asize - tvd->vdev_asize;
 219                 }
 220                 spa_prop_add_list(*nvp, ZPOOL_PROP_EXPANDSZ, NULL, space,
 221                     src);
 222 
 223                 spa_prop_add_list(*nvp, ZPOOL_PROP_READONLY, NULL,
 224                     (spa_mode(spa) == FREAD), src);
 225 
 226                 cap = (size == 0) ? 0 : (alloc * 100 / size);
 227                 spa_prop_add_list(*nvp, ZPOOL_PROP_CAPACITY, NULL, cap, src);
 228 
 229                 spa_prop_add_list(*nvp, ZPOOL_PROP_DEDUPRATIO, NULL,
 230                     ddt_get_pool_dedup_ratio(spa), src);
 231 
 232                 spa_prop_add_list(*nvp, ZPOOL_PROP_HEALTH, NULL,
 233                     rvd->vdev_state, src);
 234 
 235                 version = spa_version(spa);
 236                 if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION))
 237                         src = ZPROP_SRC_DEFAULT;
 238                 else
 239                         src = ZPROP_SRC_LOCAL;
 240                 spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL, version, src);
 241         }
 242 
 243         if (pool != NULL) {
 244                 dsl_dir_t *freedir = pool->dp_free_dir;
 245 
 246                 /*
 247                  * The $FREE directory was introduced in SPA_VERSION_DEADLISTS,
 248                  * when opening pools before this version freedir will be NULL.
 249                  */
 250                 if (freedir != NULL) {
 251                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING, NULL,
 252                             freedir->dd_phys->dd_used_bytes, src);
 253                 } else {
 254                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING,
 255                             NULL, 0, src);
 256                 }
 257         }
 258 
 259         spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
 260 
 261         if (spa->spa_comment != NULL) {
 262                 spa_prop_add_list(*nvp, ZPOOL_PROP_COMMENT, spa->spa_comment,
 263                     0, ZPROP_SRC_LOCAL);
 264         }
 265 
 266         if (spa->spa_root != NULL)
 267                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
 268                     0, ZPROP_SRC_LOCAL);
 269 
 270         if ((dp = list_head(&spa->spa_config_list)) != NULL) {
 271                 if (dp->scd_path == NULL) {
 272                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 273                             "none", 0, ZPROP_SRC_LOCAL);
 274                 } else if (strcmp(dp->scd_path, spa_config_path) != 0) {
 275                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 276                             dp->scd_path, 0, ZPROP_SRC_LOCAL);
 277                 }
 278         }
 279 }
 280 
 281 /*
 282  * Get zpool property values.
 283  */
 284 int
 285 spa_prop_get(spa_t *spa, nvlist_t **nvp)
 286 {
 287         objset_t *mos = spa->spa_meta_objset;
 288         zap_cursor_t zc;
 289         zap_attribute_t za;
 290         int err;
 291 
 292         VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 293 
 294         mutex_enter(&spa->spa_props_lock);
 295 
 296         /*
 297          * Get properties from the spa config.
 298          */
 299         spa_prop_get_config(spa, nvp);
 300 
 301         /* If no pool property object, no more prop to get. */
 302         if (mos == NULL || spa->spa_pool_props_object == 0) {
 303                 mutex_exit(&spa->spa_props_lock);
 304                 return (0);
 305         }
 306 
 307         /*
 308          * Get properties from the MOS pool property object.
 309          */
 310         for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
 311             (err = zap_cursor_retrieve(&zc, &za)) == 0;
 312             zap_cursor_advance(&zc)) {
 313                 uint64_t intval = 0;
 314                 char *strval = NULL;
 315                 zprop_source_t src = ZPROP_SRC_DEFAULT;
 316                 zpool_prop_t prop;
 317 
 318                 if ((prop = zpool_name_to_prop(za.za_name)) == ZPROP_INVAL)
 319                         continue;
 320 
 321                 switch (za.za_integer_length) {
 322                 case 8:
 323                         /* integer property */
 324                         if (za.za_first_integer !=
 325                             zpool_prop_default_numeric(prop))
 326                                 src = ZPROP_SRC_LOCAL;
 327 
 328                         if (prop == ZPOOL_PROP_BOOTFS) {
 329                                 dsl_pool_t *dp;
 330                                 dsl_dataset_t *ds = NULL;
 331 
 332                                 dp = spa_get_dsl(spa);
 333                                 dsl_pool_config_enter(dp, FTAG);
 334                                 if (err = dsl_dataset_hold_obj(dp,
 335                                     za.za_first_integer, FTAG, &ds)) {
 336                                         dsl_pool_config_exit(dp, FTAG);
 337                                         break;
 338                                 }
 339 
 340                                 strval = kmem_alloc(
 341                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1,
 342                                     KM_SLEEP);
 343                                 dsl_dataset_name(ds, strval);
 344                                 dsl_dataset_rele(ds, FTAG);
 345                                 dsl_pool_config_exit(dp, FTAG);
 346                         } else {
 347                                 strval = NULL;
 348                                 intval = za.za_first_integer;
 349                         }
 350 
 351                         spa_prop_add_list(*nvp, prop, strval, intval, src);
 352 
 353                         if (strval != NULL)
 354                                 kmem_free(strval,
 355                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1);
 356 
 357                         break;
 358 
 359                 case 1:
 360                         /* string property */
 361                         strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
 362                         err = zap_lookup(mos, spa->spa_pool_props_object,
 363                             za.za_name, 1, za.za_num_integers, strval);
 364                         if (err) {
 365                                 kmem_free(strval, za.za_num_integers);
 366                                 break;
 367                         }
 368                         spa_prop_add_list(*nvp, prop, strval, 0, src);
 369                         kmem_free(strval, za.za_num_integers);
 370                         break;
 371 
 372                 default:
 373                         break;
 374                 }
 375         }
 376         zap_cursor_fini(&zc);
 377         mutex_exit(&spa->spa_props_lock);
 378 out:
 379         if (err && err != ENOENT) {
 380                 nvlist_free(*nvp);
 381                 *nvp = NULL;
 382                 return (err);
 383         }
 384 
 385         return (0);
 386 }
 387 
 388 /*
 389  * Validate the given pool properties nvlist and modify the list
 390  * for the property values to be set.
 391  */
 392 static int
 393 spa_prop_validate(spa_t *spa, nvlist_t *props)
 394 {
 395         nvpair_t *elem;
 396         int error = 0, reset_bootfs = 0;
 397         uint64_t objnum = 0;
 398         boolean_t has_feature = B_FALSE;
 399 
 400         elem = NULL;
 401         while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
 402                 uint64_t intval;
 403                 char *strval, *slash, *check, *fname;
 404                 const char *propname = nvpair_name(elem);
 405                 zpool_prop_t prop = zpool_name_to_prop(propname);
 406 
 407                 switch (prop) {
 408                 case ZPROP_INVAL:
 409                         if (!zpool_prop_feature(propname)) {
 410                                 error = SET_ERROR(EINVAL);
 411                                 break;
 412                         }
 413 
 414                         /*
 415                          * Sanitize the input.
 416                          */
 417                         if (nvpair_type(elem) != DATA_TYPE_UINT64) {
 418                                 error = SET_ERROR(EINVAL);
 419                                 break;
 420                         }
 421 
 422                         if (nvpair_value_uint64(elem, &intval) != 0) {
 423                                 error = SET_ERROR(EINVAL);
 424                                 break;
 425                         }
 426 
 427                         if (intval != 0) {
 428                                 error = SET_ERROR(EINVAL);
 429                                 break;
 430                         }
 431 
 432                         fname = strchr(propname, '@') + 1;
 433                         if (zfeature_lookup_name(fname, NULL) != 0) {
 434                                 error = SET_ERROR(EINVAL);
 435                                 break;
 436                         }
 437 
 438                         has_feature = B_TRUE;
 439                         break;
 440 
 441                 case ZPOOL_PROP_VERSION:
 442                         error = nvpair_value_uint64(elem, &intval);
 443                         if (!error &&
 444                             (intval < spa_version(spa) ||
 445                             intval > SPA_VERSION_BEFORE_FEATURES ||
 446                             has_feature))
 447                                 error = SET_ERROR(EINVAL);
 448                         break;
 449 
 450                 case ZPOOL_PROP_DELEGATION:
 451                 case ZPOOL_PROP_AUTOREPLACE:
 452                 case ZPOOL_PROP_LISTSNAPS:
 453                 case ZPOOL_PROP_AUTOEXPAND:
 454                         error = nvpair_value_uint64(elem, &intval);
 455                         if (!error && intval > 1)
 456                                 error = SET_ERROR(EINVAL);
 457                         break;
 458 
 459                 case ZPOOL_PROP_BOOTFS:
 460                         /*
 461                          * If the pool version is less than SPA_VERSION_BOOTFS,
 462                          * or the pool is still being created (version == 0),
 463                          * the bootfs property cannot be set.
 464                          */
 465                         if (spa_version(spa) < SPA_VERSION_BOOTFS) {
 466                                 error = SET_ERROR(ENOTSUP);
 467                                 break;
 468                         }
 469 
 470                         /*
 471                          * Make sure the vdev config is bootable
 472                          */
 473                         if (!vdev_is_bootable(spa->spa_root_vdev)) {
 474                                 error = SET_ERROR(ENOTSUP);
 475                                 break;
 476                         }
 477 
 478                         reset_bootfs = 1;
 479 
 480                         error = nvpair_value_string(elem, &strval);
 481 
 482                         if (!error) {
 483                                 objset_t *os;
 484                                 uint64_t compress;
 485 
 486                                 if (strval == NULL || strval[0] == '\0') {
 487                                         objnum = zpool_prop_default_numeric(
 488                                             ZPOOL_PROP_BOOTFS);
 489                                         break;
 490                                 }
 491 
 492                                 if (error = dmu_objset_hold(strval, FTAG, &os))
 493                                         break;
 494 
 495                                 /* Must be ZPL and not gzip compressed. */
 496 
 497                                 if (dmu_objset_type(os) != DMU_OST_ZFS) {
 498                                         error = SET_ERROR(ENOTSUP);
 499                                 } else if ((error =
 500                                     dsl_prop_get_int_ds(dmu_objset_ds(os),
 501                                     zfs_prop_to_name(ZFS_PROP_COMPRESSION),
 502                                     &compress)) == 0 &&
 503                                     !BOOTFS_COMPRESS_VALID(compress)) {
 504                                         error = SET_ERROR(ENOTSUP);
 505                                 } else {
 506                                         objnum = dmu_objset_id(os);
 507                                 }
 508                                 dmu_objset_rele(os, FTAG);
 509                         }
 510                         break;
 511 
 512                 case ZPOOL_PROP_FAILUREMODE:
 513                         error = nvpair_value_uint64(elem, &intval);
 514                         if (!error && (intval < ZIO_FAILURE_MODE_WAIT ||
 515                             intval > ZIO_FAILURE_MODE_PANIC))
 516                                 error = SET_ERROR(EINVAL);
 517 
 518                         /*
 519                          * This is a special case which only occurs when
 520                          * the pool has completely failed. This allows
 521                          * the user to change the in-core failmode property
 522                          * without syncing it out to disk (I/Os might
 523                          * currently be blocked). We do this by returning
 524                          * EIO to the caller (spa_prop_set) to trick it
 525                          * into thinking we encountered a property validation
 526                          * error.
 527                          */
 528                         if (!error && spa_suspended(spa)) {
 529                                 spa->spa_failmode = intval;
 530                                 error = SET_ERROR(EIO);
 531                         }
 532                         break;
 533 
 534                 case ZPOOL_PROP_CACHEFILE:
 535                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 536                                 break;
 537 
 538                         if (strval[0] == '\0')
 539                                 break;
 540 
 541                         if (strcmp(strval, "none") == 0)
 542                                 break;
 543 
 544                         if (strval[0] != '/') {
 545                                 error = SET_ERROR(EINVAL);
 546                                 break;
 547                         }
 548 
 549                         slash = strrchr(strval, '/');
 550                         ASSERT(slash != NULL);
 551 
 552                         if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
 553                             strcmp(slash, "/..") == 0)
 554                                 error = SET_ERROR(EINVAL);
 555                         break;
 556 
 557                 case ZPOOL_PROP_COMMENT:
 558                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 559                                 break;
 560                         for (check = strval; *check != '\0'; check++) {
 561                                 /*
 562                                  * The kernel doesn't have an easy isprint()
 563                                  * check.  For this kernel check, we merely
 564                                  * check ASCII apart from DEL.  Fix this if
 565                                  * there is an easy-to-use kernel isprint().
 566                                  */
 567                                 if (*check >= 0x7f) {
 568                                         error = SET_ERROR(EINVAL);
 569                                         break;
 570                                 }
 571                                 check++;
 572                         }
 573                         if (strlen(strval) > ZPROP_MAX_COMMENT)
 574                                 error = E2BIG;
 575                         break;
 576 
 577                 case ZPOOL_PROP_DEDUPDITTO:
 578                         if (spa_version(spa) < SPA_VERSION_DEDUP)
 579                                 error = SET_ERROR(ENOTSUP);
 580                         else
 581                                 error = nvpair_value_uint64(elem, &intval);
 582                         if (error == 0 &&
 583                             intval != 0 && intval < ZIO_DEDUPDITTO_MIN)
 584                                 error = SET_ERROR(EINVAL);
 585                         break;
 586                 }
 587 
 588                 if (error)
 589                         break;
 590         }
 591 
 592         if (!error && reset_bootfs) {
 593                 error = nvlist_remove(props,
 594                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
 595 
 596                 if (!error) {
 597                         error = nvlist_add_uint64(props,
 598                             zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
 599                 }
 600         }
 601 
 602         return (error);
 603 }
 604 
 605 void
 606 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
 607 {
 608         char *cachefile;
 609         spa_config_dirent_t *dp;
 610 
 611         if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
 612             &cachefile) != 0)
 613                 return;
 614 
 615         dp = kmem_alloc(sizeof (spa_config_dirent_t),
 616             KM_SLEEP);
 617 
 618         if (cachefile[0] == '\0')
 619                 dp->scd_path = spa_strdup(spa_config_path);
 620         else if (strcmp(cachefile, "none") == 0)
 621                 dp->scd_path = NULL;
 622         else
 623                 dp->scd_path = spa_strdup(cachefile);
 624 
 625         list_insert_head(&spa->spa_config_list, dp);
 626         if (need_sync)
 627                 spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
 628 }
 629 
 630 int
 631 spa_prop_set(spa_t *spa, nvlist_t *nvp)
 632 {
 633         int error;
 634         nvpair_t *elem = NULL;
 635         boolean_t need_sync = B_FALSE;
 636 
 637         if ((error = spa_prop_validate(spa, nvp)) != 0)
 638                 return (error);
 639 
 640         while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
 641                 zpool_prop_t prop = zpool_name_to_prop(nvpair_name(elem));
 642 
 643                 if (prop == ZPOOL_PROP_CACHEFILE ||
 644                     prop == ZPOOL_PROP_ALTROOT ||
 645                     prop == ZPOOL_PROP_READONLY)
 646                         continue;
 647 
 648                 if (prop == ZPOOL_PROP_VERSION || prop == ZPROP_INVAL) {
 649                         uint64_t ver;
 650 
 651                         if (prop == ZPOOL_PROP_VERSION) {
 652                                 VERIFY(nvpair_value_uint64(elem, &ver) == 0);
 653                         } else {
 654                                 ASSERT(zpool_prop_feature(nvpair_name(elem)));
 655                                 ver = SPA_VERSION_FEATURES;
 656                                 need_sync = B_TRUE;
 657                         }
 658 
 659                         /* Save time if the version is already set. */
 660                         if (ver == spa_version(spa))
 661                                 continue;
 662 
 663                         /*
 664                          * In addition to the pool directory object, we might
 665                          * create the pool properties object, the features for
 666                          * read object, the features for write object, or the
 667                          * feature descriptions object.
 668                          */
 669                         error = dsl_sync_task(spa->spa_name, NULL,
 670                             spa_sync_version, &ver, 6);
 671                         if (error)
 672                                 return (error);
 673                         continue;
 674                 }
 675 
 676                 need_sync = B_TRUE;
 677                 break;
 678         }
 679 
 680         if (need_sync) {
 681                 return (dsl_sync_task(spa->spa_name, NULL, spa_sync_props,
 682                     nvp, 6));
 683         }
 684 
 685         return (0);
 686 }
 687 
 688 /*
 689  * If the bootfs property value is dsobj, clear it.
 690  */
 691 void
 692 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
 693 {
 694         if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
 695                 VERIFY(zap_remove(spa->spa_meta_objset,
 696                     spa->spa_pool_props_object,
 697                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
 698                 spa->spa_bootfs = 0;
 699         }
 700 }
 701 
 702 /*ARGSUSED*/
 703 static int
 704 spa_change_guid_check(void *arg, dmu_tx_t *tx)
 705 {
 706         uint64_t *newguid = arg;
 707         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 708         vdev_t *rvd = spa->spa_root_vdev;
 709         uint64_t vdev_state;
 710 
 711         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
 712         vdev_state = rvd->vdev_state;
 713         spa_config_exit(spa, SCL_STATE, FTAG);
 714 
 715         if (vdev_state != VDEV_STATE_HEALTHY)
 716                 return (SET_ERROR(ENXIO));
 717 
 718         ASSERT3U(spa_guid(spa), !=, *newguid);
 719 
 720         return (0);
 721 }
 722 
 723 static void
 724 spa_change_guid_sync(void *arg, dmu_tx_t *tx)
 725 {
 726         uint64_t *newguid = arg;
 727         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 728         uint64_t oldguid;
 729         vdev_t *rvd = spa->spa_root_vdev;
 730 
 731         oldguid = spa_guid(spa);
 732 
 733         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
 734         rvd->vdev_guid = *newguid;
 735         rvd->vdev_guid_sum += (*newguid - oldguid);
 736         vdev_config_dirty(rvd);
 737         spa_config_exit(spa, SCL_STATE, FTAG);
 738 
 739         spa_history_log_internal(spa, "guid change", tx, "old=%llu new=%llu",
 740             oldguid, *newguid);
 741 }
 742 
 743 /*
 744  * Change the GUID for the pool.  This is done so that we can later
 745  * re-import a pool built from a clone of our own vdevs.  We will modify
 746  * the root vdev's guid, our own pool guid, and then mark all of our
 747  * vdevs dirty.  Note that we must make sure that all our vdevs are
 748  * online when we do this, or else any vdevs that weren't present
 749  * would be orphaned from our pool.  We are also going to issue a
 750  * sysevent to update any watchers.
 751  */
 752 int
 753 spa_change_guid(spa_t *spa)
 754 {
 755         int error;
 756         uint64_t guid;
 757 
 758         mutex_enter(&spa->spa_vdev_top_lock);
 759         mutex_enter(&spa_namespace_lock);
 760         guid = spa_generate_guid(NULL);
 761 
 762         error = dsl_sync_task(spa->spa_name, spa_change_guid_check,
 763             spa_change_guid_sync, &guid, 5);
 764 
 765         if (error == 0) {
 766                 spa_config_sync(spa, B_FALSE, B_TRUE);
 767                 spa_event_notify(spa, NULL, ESC_ZFS_POOL_REGUID);
 768         }
 769 
 770         mutex_exit(&spa_namespace_lock);
 771         mutex_exit(&spa->spa_vdev_top_lock);
 772 
 773         return (error);
 774 }
 775 
 776 /*
 777  * ==========================================================================
 778  * SPA state manipulation (open/create/destroy/import/export)
 779  * ==========================================================================
 780  */
 781 
 782 static int
 783 spa_error_entry_compare(const void *a, const void *b)
 784 {
 785         spa_error_entry_t *sa = (spa_error_entry_t *)a;
 786         spa_error_entry_t *sb = (spa_error_entry_t *)b;
 787         int ret;
 788 
 789         ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
 790             sizeof (zbookmark_t));
 791 
 792         if (ret < 0)
 793                 return (-1);
 794         else if (ret > 0)
 795                 return (1);
 796         else
 797                 return (0);
 798 }
 799 
 800 /*
 801  * Utility function which retrieves copies of the current logs and
 802  * re-initializes them in the process.
 803  */
 804 void
 805 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
 806 {
 807         ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
 808 
 809         bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
 810         bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));
 811 
 812         avl_create(&spa->spa_errlist_scrub,
 813             spa_error_entry_compare, sizeof (spa_error_entry_t),
 814             offsetof(spa_error_entry_t, se_avl));
 815         avl_create(&spa->spa_errlist_last,
 816             spa_error_entry_compare, sizeof (spa_error_entry_t),
 817             offsetof(spa_error_entry_t, se_avl));
 818 }
 819 
 820 static void
 821 spa_taskqs_init(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
 822 {
 823         const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
 824         enum zti_modes mode = ztip->zti_mode;
 825         uint_t value = ztip->zti_value;
 826         uint_t count = ztip->zti_count;
 827         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 828         char name[32];
 829         uint_t flags = 0;
 830         boolean_t batch = B_FALSE;
 831 
 832         if (mode == ZTI_MODE_NULL) {
 833                 tqs->stqs_count = 0;
 834                 tqs->stqs_taskq = NULL;
 835                 return;
 836         }
 837 
 838         ASSERT3U(count, >, 0);
 839 
 840         tqs->stqs_count = count;
 841         tqs->stqs_taskq = kmem_alloc(count * sizeof (taskq_t *), KM_SLEEP);
 842 
 843         switch (mode) {
 844         case ZTI_MODE_FIXED:
 845                 ASSERT3U(value, >=, 1);
 846                 value = MAX(value, 1);
 847                 break;
 848 
 849         case ZTI_MODE_BATCH:
 850                 batch = B_TRUE;
 851                 flags |= TASKQ_THREADS_CPU_PCT;
 852                 value = zio_taskq_batch_pct;
 853                 break;
 854 
 855         default:
 856                 panic("unrecognized mode for %s_%s taskq (%u:%u) in "
 857                     "spa_activate()",
 858                     zio_type_name[t], zio_taskq_types[q], mode, value);
 859                 break;
 860         }
 861 
 862         for (uint_t i = 0; i < count; i++) {
 863                 taskq_t *tq;
 864 
 865                 if (count > 1) {
 866                         (void) snprintf(name, sizeof (name), "%s_%s_%u",
 867                             zio_type_name[t], zio_taskq_types[q], i);
 868                 } else {
 869                         (void) snprintf(name, sizeof (name), "%s_%s",
 870                             zio_type_name[t], zio_taskq_types[q]);
 871                 }
 872 
 873                 if (zio_taskq_sysdc && spa->spa_proc != &p0) {
 874                         if (batch)
 875                                 flags |= TASKQ_DC_BATCH;
 876 
 877                         tq = taskq_create_sysdc(name, value, 50, INT_MAX,
 878                             spa->spa_proc, zio_taskq_basedc, flags);
 879                 } else {
 880                         pri_t pri = maxclsyspri;
 881                         /*
 882                          * The write issue taskq can be extremely CPU
 883                          * intensive.  Run it at slightly lower priority
 884                          * than the other taskqs.
 885                          */
 886                         if (t == ZIO_TYPE_WRITE && q == ZIO_TASKQ_ISSUE)
 887                                 pri--;
 888 
 889                         tq = taskq_create_proc(name, value, pri, 50,
 890                             INT_MAX, spa->spa_proc, flags);
 891                 }
 892 
 893                 tqs->stqs_taskq[i] = tq;
 894         }
 895 }
 896 
 897 static void
 898 spa_taskqs_fini(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
 899 {
 900         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 901 
 902         if (tqs->stqs_taskq == NULL) {
 903                 ASSERT0(tqs->stqs_count);
 904                 return;
 905         }
 906 
 907         for (uint_t i = 0; i < tqs->stqs_count; i++) {
 908                 ASSERT3P(tqs->stqs_taskq[i], !=, NULL);
 909                 taskq_destroy(tqs->stqs_taskq[i]);
 910         }
 911 
 912         kmem_free(tqs->stqs_taskq, tqs->stqs_count * sizeof (taskq_t *));
 913         tqs->stqs_taskq = NULL;
 914 }
 915 
 916 /*
 917  * Dispatch a task to the appropriate taskq for the ZFS I/O type and priority.
 918  * Note that a type may have multiple discrete taskqs to avoid lock contention
 919  * on the taskq itself. In that case we choose which taskq at random by using
 920  * the low bits of gethrtime().
 921  */
 922 void
 923 spa_taskq_dispatch_ent(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
 924     task_func_t *func, void *arg, uint_t flags, taskq_ent_t *ent)
 925 {
 926         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 927         taskq_t *tq;
 928 
 929         ASSERT3P(tqs->stqs_taskq, !=, NULL);
 930         ASSERT3U(tqs->stqs_count, !=, 0);
 931 
 932         if (tqs->stqs_count == 1) {
 933                 tq = tqs->stqs_taskq[0];
 934         } else {
 935                 tq = tqs->stqs_taskq[gethrtime() % tqs->stqs_count];
 936         }
 937 
 938         taskq_dispatch_ent(tq, func, arg, flags, ent);
 939 }
 940 
 941 static void
 942 spa_create_zio_taskqs(spa_t *spa)
 943 {
 944         for (int t = 0; t < ZIO_TYPES; t++) {
 945                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
 946                         spa_taskqs_init(spa, t, q);
 947                 }
 948         }
 949 }
 950 
 951 #ifdef _KERNEL
 952 static void
 953 spa_thread(void *arg)
 954 {
 955         callb_cpr_t cprinfo;
 956 
 957         spa_t *spa = arg;
 958         user_t *pu = PTOU(curproc);
 959 
 960         CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
 961             spa->spa_name);
 962 
 963         ASSERT(curproc != &p0);
 964         (void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
 965             "zpool-%s", spa->spa_name);
 966         (void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
 967 
 968         /* bind this thread to the requested psrset */
 969         if (zio_taskq_psrset_bind != PS_NONE) {
 970                 pool_lock();
 971                 mutex_enter(&cpu_lock);
 972                 mutex_enter(&pidlock);
 973                 mutex_enter(&curproc->p_lock);
 974 
 975                 if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
 976                     0, NULL, NULL) == 0)  {
 977                         curthread->t_bind_pset = zio_taskq_psrset_bind;
 978                 } else {
 979                         cmn_err(CE_WARN,
 980                             "Couldn't bind process for zfs pool \"%s\" to "
 981                             "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
 982                 }
 983 
 984                 mutex_exit(&curproc->p_lock);
 985                 mutex_exit(&pidlock);
 986                 mutex_exit(&cpu_lock);
 987                 pool_unlock();
 988         }
 989 
 990         if (zio_taskq_sysdc) {
 991                 sysdc_thread_enter(curthread, 100, 0);
 992         }
 993 
 994         spa->spa_proc = curproc;
 995         spa->spa_did = curthread->t_did;
 996 
 997         spa_create_zio_taskqs(spa);
 998 
 999         mutex_enter(&spa->spa_proc_lock);
1000         ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
1001 
1002         spa->spa_proc_state = SPA_PROC_ACTIVE;
1003         cv_broadcast(&spa->spa_proc_cv);
1004 
1005         CALLB_CPR_SAFE_BEGIN(&cprinfo);
1006         while (spa->spa_proc_state == SPA_PROC_ACTIVE)
1007                 cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1008         CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
1009 
1010         ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
1011         spa->spa_proc_state = SPA_PROC_GONE;
1012         spa->spa_proc = &p0;
1013         cv_broadcast(&spa->spa_proc_cv);
1014         CALLB_CPR_EXIT(&cprinfo);   /* drops spa_proc_lock */
1015 
1016         mutex_enter(&curproc->p_lock);
1017         lwp_exit();
1018 }
1019 #endif
1020 
1021 /*
1022  * Activate an uninitialized pool.
1023  */
1024 static void
1025 spa_activate(spa_t *spa, int mode)
1026 {
1027         ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
1028 
1029         spa->spa_state = POOL_STATE_ACTIVE;
1030         spa->spa_mode = mode;
1031 
1032         spa->spa_normal_class = metaslab_class_create(spa, zfs_metaslab_ops);
1033         spa->spa_log_class = metaslab_class_create(spa, zfs_metaslab_ops);
1034 
1035         /* Try to create a covering process */
1036         mutex_enter(&spa->spa_proc_lock);
1037         ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
1038         ASSERT(spa->spa_proc == &p0);
1039         spa->spa_did = 0;
1040 
1041         /* Only create a process if we're going to be around a while. */
1042         if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
1043                 if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
1044                     NULL, 0) == 0) {
1045                         spa->spa_proc_state = SPA_PROC_CREATED;
1046                         while (spa->spa_proc_state == SPA_PROC_CREATED) {
1047                                 cv_wait(&spa->spa_proc_cv,
1048                                     &spa->spa_proc_lock);
1049                         }
1050                         ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1051                         ASSERT(spa->spa_proc != &p0);
1052                         ASSERT(spa->spa_did != 0);
1053                 } else {
1054 #ifdef _KERNEL
1055                         cmn_err(CE_WARN,
1056                             "Couldn't create process for zfs pool \"%s\"\n",
1057                             spa->spa_name);
1058 #endif
1059                 }
1060         }
1061         mutex_exit(&spa->spa_proc_lock);
1062 
1063         /* If we didn't create a process, we need to create our taskqs. */
1064         if (spa->spa_proc == &p0) {
1065                 spa_create_zio_taskqs(spa);
1066         }
1067 
1068         list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
1069             offsetof(vdev_t, vdev_config_dirty_node));
1070         list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
1071             offsetof(vdev_t, vdev_state_dirty_node));
1072 
1073         txg_list_create(&spa->spa_vdev_txg_list,
1074             offsetof(struct vdev, vdev_txg_node));
1075 
1076         avl_create(&spa->spa_errlist_scrub,
1077             spa_error_entry_compare, sizeof (spa_error_entry_t),
1078             offsetof(spa_error_entry_t, se_avl));
1079         avl_create(&spa->spa_errlist_last,
1080             spa_error_entry_compare, sizeof (spa_error_entry_t),
1081             offsetof(spa_error_entry_t, se_avl));
1082 }
1083 
1084 /*
1085  * Opposite of spa_activate().
1086  */
1087 static void
1088 spa_deactivate(spa_t *spa)
1089 {
1090         ASSERT(spa->spa_sync_on == B_FALSE);
1091         ASSERT(spa->spa_dsl_pool == NULL);
1092         ASSERT(spa->spa_root_vdev == NULL);
1093         ASSERT(spa->spa_async_zio_root == NULL);
1094         ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
1095 
1096         txg_list_destroy(&spa->spa_vdev_txg_list);
1097 
1098         list_destroy(&spa->spa_config_dirty_list);
1099         list_destroy(&spa->spa_state_dirty_list);
1100 
1101         for (int t = 0; t < ZIO_TYPES; t++) {
1102                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
1103                         spa_taskqs_fini(spa, t, q);
1104                 }
1105         }
1106 
1107         metaslab_class_destroy(spa->spa_normal_class);
1108         spa->spa_normal_class = NULL;
1109 
1110         metaslab_class_destroy(spa->spa_log_class);
1111         spa->spa_log_class = NULL;
1112 
1113         /*
1114          * If this was part of an import or the open otherwise failed, we may
1115          * still have errors left in the queues.  Empty them just in case.
1116          */
1117         spa_errlog_drain(spa);
1118 
1119         avl_destroy(&spa->spa_errlist_scrub);
1120         avl_destroy(&spa->spa_errlist_last);
1121 
1122         spa->spa_state = POOL_STATE_UNINITIALIZED;
1123 
1124         mutex_enter(&spa->spa_proc_lock);
1125         if (spa->spa_proc_state != SPA_PROC_NONE) {
1126                 ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1127                 spa->spa_proc_state = SPA_PROC_DEACTIVATE;
1128                 cv_broadcast(&spa->spa_proc_cv);
1129                 while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
1130                         ASSERT(spa->spa_proc != &p0);
1131                         cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1132                 }
1133                 ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
1134                 spa->spa_proc_state = SPA_PROC_NONE;
1135         }
1136         ASSERT(spa->spa_proc == &p0);
1137         mutex_exit(&spa->spa_proc_lock);
1138 
1139         /*
1140          * We want to make sure spa_thread() has actually exited the ZFS
1141          * module, so that the module can't be unloaded out from underneath
1142          * it.
1143          */
1144         if (spa->spa_did != 0) {
1145                 thread_join(spa->spa_did);
1146                 spa->spa_did = 0;
1147         }
1148 }
1149 
1150 /*
1151  * Verify a pool configuration, and construct the vdev tree appropriately.  This
1152  * will create all the necessary vdevs in the appropriate layout, with each vdev
1153  * in the CLOSED state.  This will prep the pool before open/creation/import.
1154  * All vdev validation is done by the vdev_alloc() routine.
1155  */
1156 static int
1157 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
1158     uint_t id, int atype)
1159 {
1160         nvlist_t **child;
1161         uint_t children;
1162         int error;
1163 
1164         if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
1165                 return (error);
1166 
1167         if ((*vdp)->vdev_ops->vdev_op_leaf)
1168                 return (0);
1169 
1170         error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
1171             &child, &children);
1172 
1173         if (error == ENOENT)
1174                 return (0);
1175 
1176         if (error) {
1177                 vdev_free(*vdp);
1178                 *vdp = NULL;
1179                 return (SET_ERROR(EINVAL));
1180         }
1181 
1182         for (int c = 0; c < children; c++) {
1183                 vdev_t *vd;
1184                 if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
1185                     atype)) != 0) {
1186                         vdev_free(*vdp);
1187                         *vdp = NULL;
1188                         return (error);
1189                 }
1190         }
1191 
1192         ASSERT(*vdp != NULL);
1193 
1194         return (0);
1195 }
1196 
1197 /*
1198  * Opposite of spa_load().
1199  */
1200 static void
1201 spa_unload(spa_t *spa)
1202 {
1203         int i;
1204 
1205         ASSERT(MUTEX_HELD(&spa_namespace_lock));
1206 
1207         /*
1208          * Stop async tasks.
1209          */
1210         spa_async_suspend(spa);
1211 
1212         /*
1213          * Stop syncing.
1214          */
1215         if (spa->spa_sync_on) {
1216                 txg_sync_stop(spa->spa_dsl_pool);
1217                 spa->spa_sync_on = B_FALSE;
1218         }
1219 
1220         /*
1221          * Wait for any outstanding async I/O to complete.
1222          */
1223         if (spa->spa_async_zio_root != NULL) {
1224                 (void) zio_wait(spa->spa_async_zio_root);
1225                 spa->spa_async_zio_root = NULL;
1226         }
1227 
1228         bpobj_close(&spa->spa_deferred_bpobj);
1229 
1230         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1231 
1232         /*
1233          * Close all vdevs.
1234          */
1235         if (spa->spa_root_vdev)
1236                 vdev_free(spa->spa_root_vdev);
1237         ASSERT(spa->spa_root_vdev == NULL);
1238 
1239         /*
1240          * Close the dsl pool.
1241          */
1242         if (spa->spa_dsl_pool) {
1243                 dsl_pool_close(spa->spa_dsl_pool);
1244                 spa->spa_dsl_pool = NULL;
1245                 spa->spa_meta_objset = NULL;
1246         }
1247 
1248         ddt_unload(spa);
1249 
1250 
1251         /*
1252          * Drop and purge level 2 cache
1253          */
1254         spa_l2cache_drop(spa);
1255 
1256         for (i = 0; i < spa->spa_spares.sav_count; i++)
1257                 vdev_free(spa->spa_spares.sav_vdevs[i]);
1258         if (spa->spa_spares.sav_vdevs) {
1259                 kmem_free(spa->spa_spares.sav_vdevs,
1260                     spa->spa_spares.sav_count * sizeof (void *));
1261                 spa->spa_spares.sav_vdevs = NULL;
1262         }
1263         if (spa->spa_spares.sav_config) {
1264                 nvlist_free(spa->spa_spares.sav_config);
1265                 spa->spa_spares.sav_config = NULL;
1266         }
1267         spa->spa_spares.sav_count = 0;
1268 
1269         for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
1270                 vdev_clear_stats(spa->spa_l2cache.sav_vdevs[i]);
1271                 vdev_free(spa->spa_l2cache.sav_vdevs[i]);
1272         }
1273         if (spa->spa_l2cache.sav_vdevs) {
1274                 kmem_free(spa->spa_l2cache.sav_vdevs,
1275                     spa->spa_l2cache.sav_count * sizeof (void *));
1276                 spa->spa_l2cache.sav_vdevs = NULL;
1277         }
1278         if (spa->spa_l2cache.sav_config) {
1279                 nvlist_free(spa->spa_l2cache.sav_config);
1280                 spa->spa_l2cache.sav_config = NULL;
1281         }
1282         spa->spa_l2cache.sav_count = 0;
1283 
1284         spa->spa_async_suspended = 0;
1285 
1286         if (spa->spa_comment != NULL) {
1287                 spa_strfree(spa->spa_comment);
1288                 spa->spa_comment = NULL;
1289         }
1290 
1291         spa_config_exit(spa, SCL_ALL, FTAG);
1292 }
1293 
1294 /*
1295  * Load (or re-load) the current list of vdevs describing the active spares for
1296  * this pool.  When this is called, we have some form of basic information in
1297  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
1298  * then re-generate a more complete list including status information.
1299  */
1300 static void
1301 spa_load_spares(spa_t *spa)
1302 {
1303         nvlist_t **spares;
1304         uint_t nspares;
1305         int i;
1306         vdev_t *vd, *tvd;
1307 
1308         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1309 
1310         /*
1311          * First, close and free any existing spare vdevs.
1312          */
1313         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1314                 vd = spa->spa_spares.sav_vdevs[i];
1315 
1316                 /* Undo the call to spa_activate() below */
1317                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1318                     B_FALSE)) != NULL && tvd->vdev_isspare)
1319                         spa_spare_remove(tvd);
1320                 vdev_close(vd);
1321                 vdev_free(vd);
1322         }
1323 
1324         if (spa->spa_spares.sav_vdevs)
1325                 kmem_free(spa->spa_spares.sav_vdevs,
1326                     spa->spa_spares.sav_count * sizeof (void *));
1327 
1328         if (spa->spa_spares.sav_config == NULL)
1329                 nspares = 0;
1330         else
1331                 VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1332                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1333 
1334         spa->spa_spares.sav_count = (int)nspares;
1335         spa->spa_spares.sav_vdevs = NULL;
1336 
1337         if (nspares == 0)
1338                 return;
1339 
1340         /*
1341          * Construct the array of vdevs, opening them to get status in the
1342          * process.   For each spare, there is potentially two different vdev_t
1343          * structures associated with it: one in the list of spares (used only
1344          * for basic validation purposes) and one in the active vdev
1345          * configuration (if it's spared in).  During this phase we open and
1346          * validate each vdev on the spare list.  If the vdev also exists in the
1347          * active configuration, then we also mark this vdev as an active spare.
1348          */
1349         spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
1350             KM_SLEEP);
1351         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1352                 VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
1353                     VDEV_ALLOC_SPARE) == 0);
1354                 ASSERT(vd != NULL);
1355 
1356                 spa->spa_spares.sav_vdevs[i] = vd;
1357 
1358                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1359                     B_FALSE)) != NULL) {
1360                         if (!tvd->vdev_isspare)
1361                                 spa_spare_add(tvd);
1362 
1363                         /*
1364                          * We only mark the spare active if we were successfully
1365                          * able to load the vdev.  Otherwise, importing a pool
1366                          * with a bad active spare would result in strange
1367                          * behavior, because multiple pool would think the spare
1368                          * is actively in use.
1369                          *
1370                          * There is a vulnerability here to an equally bizarre
1371                          * circumstance, where a dead active spare is later
1372                          * brought back to life (onlined or otherwise).  Given
1373                          * the rarity of this scenario, and the extra complexity
1374                          * it adds, we ignore the possibility.
1375                          */
1376                         if (!vdev_is_dead(tvd))
1377                                 spa_spare_activate(tvd);
1378                 }
1379 
1380                 vd->vdev_top = vd;
1381                 vd->vdev_aux = &spa->spa_spares;
1382 
1383                 if (vdev_open(vd) != 0)
1384                         continue;
1385 
1386                 if (vdev_validate_aux(vd) == 0)
1387                         spa_spare_add(vd);
1388         }
1389 
1390         /*
1391          * Recompute the stashed list of spares, with status information
1392          * this time.
1393          */
1394         VERIFY(nvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES,
1395             DATA_TYPE_NVLIST_ARRAY) == 0);
1396 
1397         spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
1398             KM_SLEEP);
1399         for (i = 0; i < spa->spa_spares.sav_count; i++)
1400                 spares[i] = vdev_config_generate(spa,
1401                     spa->spa_spares.sav_vdevs[i], B_TRUE, VDEV_CONFIG_SPARE);
1402         VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
1403             ZPOOL_CONFIG_SPARES, spares, spa->spa_spares.sav_count) == 0);
1404         for (i = 0; i < spa->spa_spares.sav_count; i++)
1405                 nvlist_free(spares[i]);
1406         kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
1407 }
1408 
1409 /*
1410  * Load (or re-load) the current list of vdevs describing the active l2cache for
1411  * this pool.  When this is called, we have some form of basic information in
1412  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
1413  * then re-generate a more complete list including status information.
1414  * Devices which are already active have their details maintained, and are
1415  * not re-opened.
1416  */
1417 static void
1418 spa_load_l2cache(spa_t *spa)
1419 {
1420         nvlist_t **l2cache;
1421         uint_t nl2cache;
1422         int i, j, oldnvdevs;
1423         uint64_t guid;
1424         vdev_t *vd, **oldvdevs, **newvdevs;
1425         spa_aux_vdev_t *sav = &spa->spa_l2cache;
1426 
1427         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1428 
1429         if (sav->sav_config != NULL) {
1430                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
1431                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1432                 newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
1433         } else {
1434                 nl2cache = 0;
1435                 newvdevs = NULL;
1436         }
1437 
1438         oldvdevs = sav->sav_vdevs;
1439         oldnvdevs = sav->sav_count;
1440         sav->sav_vdevs = NULL;
1441         sav->sav_count = 0;
1442 
1443         /*
1444          * Process new nvlist of vdevs.
1445          */
1446         for (i = 0; i < nl2cache; i++) {
1447                 VERIFY(nvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID,
1448                     &guid) == 0);
1449 
1450                 newvdevs[i] = NULL;
1451                 for (j = 0; j < oldnvdevs; j++) {
1452                         vd = oldvdevs[j];
1453                         if (vd != NULL && guid == vd->vdev_guid) {
1454                                 /*
1455                                  * Retain previous vdev for add/remove ops.
1456                                  */
1457                                 newvdevs[i] = vd;
1458                                 oldvdevs[j] = NULL;
1459                                 break;
1460                         }
1461                 }
1462 
1463                 if (newvdevs[i] == NULL) {
1464                         /*
1465                          * Create new vdev
1466                          */
1467                         VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
1468                             VDEV_ALLOC_L2CACHE) == 0);
1469                         ASSERT(vd != NULL);
1470                         newvdevs[i] = vd;
1471 
1472                         /*
1473                          * Commit this vdev as an l2cache device,
1474                          * even if it fails to open.
1475                          */
1476                         spa_l2cache_add(vd);
1477 
1478                         vd->vdev_top = vd;
1479                         vd->vdev_aux = sav;
1480 
1481                         spa_l2cache_activate(vd);
1482 
1483                         if (vdev_open(vd) != 0)
1484                                 continue;
1485 
1486                         (void) vdev_validate_aux(vd);
1487 
1488                         if (!vdev_is_dead(vd))
1489                                 l2arc_add_vdev(spa, vd);
1490                 }
1491         }
1492 
1493         /*
1494          * Purge vdevs that were dropped
1495          */
1496         for (i = 0; i < oldnvdevs; i++) {
1497                 uint64_t pool;
1498 
1499                 vd = oldvdevs[i];
1500                 if (vd != NULL) {
1501                         ASSERT(vd->vdev_isl2cache);
1502 
1503                         if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
1504                             pool != 0ULL && l2arc_vdev_present(vd))
1505                                 l2arc_remove_vdev(vd);
1506                         vdev_clear_stats(vd);
1507                         vdev_free(vd);
1508                 }
1509         }
1510 
1511         if (oldvdevs)
1512                 kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
1513 
1514         if (sav->sav_config == NULL)
1515                 goto out;
1516 
1517         sav->sav_vdevs = newvdevs;
1518         sav->sav_count = (int)nl2cache;
1519 
1520         /*
1521          * Recompute the stashed list of l2cache devices, with status
1522          * information this time.
1523          */
1524         VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
1525             DATA_TYPE_NVLIST_ARRAY) == 0);
1526 
1527         l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
1528         for (i = 0; i < sav->sav_count; i++)
1529                 l2cache[i] = vdev_config_generate(spa,
1530                     sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);
1531         VERIFY(nvlist_add_nvlist_array(sav->sav_config,
1532             ZPOOL_CONFIG_L2CACHE, l2cache, sav->sav_count) == 0);
1533 out:
1534         for (i = 0; i < sav->sav_count; i++)
1535                 nvlist_free(l2cache[i]);
1536         if (sav->sav_count)
1537                 kmem_free(l2cache, sav->sav_count * sizeof (void *));
1538 }
1539 
1540 static int
1541 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
1542 {
1543         dmu_buf_t *db;
1544         char *packed = NULL;
1545         size_t nvsize = 0;
1546         int error;
1547         *value = NULL;
1548 
1549         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
1550         nvsize = *(uint64_t *)db->db_data;
1551         dmu_buf_rele(db, FTAG);
1552 
1553         packed = kmem_alloc(nvsize, KM_SLEEP);
1554         error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
1555             DMU_READ_PREFETCH);
1556         if (error == 0)
1557                 error = nvlist_unpack(packed, nvsize, value, 0);
1558         kmem_free(packed, nvsize);
1559 
1560         return (error);
1561 }
1562 
1563 /*
1564  * Checks to see if the given vdev could not be opened, in which case we post a
1565  * sysevent to notify the autoreplace code that the device has been removed.
1566  */
1567 static void
1568 spa_check_removed(vdev_t *vd)
1569 {
1570         for (int c = 0; c < vd->vdev_children; c++)
1571                 spa_check_removed(vd->vdev_child[c]);
1572 
1573         if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd) &&
1574             !vd->vdev_ishole) {
1575                 zfs_post_autoreplace(vd->vdev_spa, vd);
1576                 spa_event_notify(vd->vdev_spa, vd, ESC_ZFS_VDEV_CHECK);
1577         }
1578 }
1579 
1580 /*
1581  * Validate the current config against the MOS config
1582  */
1583 static boolean_t
1584 spa_config_valid(spa_t *spa, nvlist_t *config)
1585 {
1586         vdev_t *mrvd, *rvd = spa->spa_root_vdev;
1587         nvlist_t *nv;
1588 
1589         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nv) == 0);
1590 
1591         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1592         VERIFY(spa_config_parse(spa, &mrvd, nv, NULL, 0, VDEV_ALLOC_LOAD) == 0);
1593 
1594         ASSERT3U(rvd->vdev_children, ==, mrvd->vdev_children);
1595 
1596         /*
1597          * If we're doing a normal import, then build up any additional
1598          * diagnostic information about missing devices in this config.
1599          * We'll pass this up to the user for further processing.
1600          */
1601         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG)) {
1602                 nvlist_t **child, *nv;
1603                 uint64_t idx = 0;
1604 
1605                 child = kmem_alloc(rvd->vdev_children * sizeof (nvlist_t **),
1606                     KM_SLEEP);
1607                 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1608 
1609                 for (int c = 0; c < rvd->vdev_children; c++) {
1610                         vdev_t *tvd = rvd->vdev_child[c];
1611                         vdev_t *mtvd  = mrvd->vdev_child[c];
1612 
1613                         if (tvd->vdev_ops == &vdev_missing_ops &&
1614                             mtvd->vdev_ops != &vdev_missing_ops &&
1615                             mtvd->vdev_islog)
1616                                 child[idx++] = vdev_config_generate(spa, mtvd,
1617                                     B_FALSE, 0);
1618                 }
1619 
1620                 if (idx) {
1621                         VERIFY(nvlist_add_nvlist_array(nv,
1622                             ZPOOL_CONFIG_CHILDREN, child, idx) == 0);
1623                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
1624                             ZPOOL_CONFIG_MISSING_DEVICES, nv) == 0);
1625 
1626                         for (int i = 0; i < idx; i++)
1627                                 nvlist_free(child[i]);
1628                 }
1629                 nvlist_free(nv);
1630                 kmem_free(child, rvd->vdev_children * sizeof (char **));
1631         }
1632 
1633         /*
1634          * Compare the root vdev tree with the information we have
1635          * from the MOS config (mrvd). Check each top-level vdev
1636          * with the corresponding MOS config top-level (mtvd).
1637          */
1638         for (int c = 0; c < rvd->vdev_children; c++) {
1639                 vdev_t *tvd = rvd->vdev_child[c];
1640                 vdev_t *mtvd  = mrvd->vdev_child[c];
1641 
1642                 /*
1643                  * Resolve any "missing" vdevs in the current configuration.
1644                  * If we find that the MOS config has more accurate information
1645                  * about the top-level vdev then use that vdev instead.
1646                  */
1647                 if (tvd->vdev_ops == &vdev_missing_ops &&
1648                     mtvd->vdev_ops != &vdev_missing_ops) {
1649 
1650                         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG))
1651                                 continue;
1652 
1653                         /*
1654                          * Device specific actions.
1655                          */
1656                         if (mtvd->vdev_islog) {
1657                                 spa_set_log_state(spa, SPA_LOG_CLEAR);
1658                         } else {
1659                                 /*
1660                                  * XXX - once we have 'readonly' pool
1661                                  * support we should be able to handle
1662                                  * missing data devices by transitioning
1663                                  * the pool to readonly.
1664                                  */
1665                                 continue;
1666                         }
1667 
1668                         /*
1669                          * Swap the missing vdev with the data we were
1670                          * able to obtain from the MOS config.
1671                          */
1672                         vdev_remove_child(rvd, tvd);
1673                         vdev_remove_child(mrvd, mtvd);
1674 
1675                         vdev_add_child(rvd, mtvd);
1676                         vdev_add_child(mrvd, tvd);
1677 
1678                         spa_config_exit(spa, SCL_ALL, FTAG);
1679                         vdev_load(mtvd);
1680                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1681 
1682                         vdev_reopen(rvd);
1683                 } else if (mtvd->vdev_islog) {
1684                         /*
1685                          * Load the slog device's state from the MOS config
1686                          * since it's possible that the label does not
1687                          * contain the most up-to-date information.
1688                          */
1689                         vdev_load_log_state(tvd, mtvd);
1690                         vdev_reopen(tvd);
1691                 }
1692         }
1693         vdev_free(mrvd);
1694         spa_config_exit(spa, SCL_ALL, FTAG);
1695 
1696         /*
1697          * Ensure we were able to validate the config.
1698          */
1699         return (rvd->vdev_guid_sum == spa->spa_uberblock.ub_guid_sum);
1700 }
1701 
1702 /*
1703  * Check for missing log devices
1704  */
1705 static boolean_t
1706 spa_check_logs(spa_t *spa)
1707 {
1708         boolean_t rv = B_FALSE;
1709 
1710         switch (spa->spa_log_state) {
1711         case SPA_LOG_MISSING:
1712                 /* need to recheck in case slog has been restored */
1713         case SPA_LOG_UNKNOWN:
1714                 rv = (dmu_objset_find(spa->spa_name, zil_check_log_chain,
1715                     NULL, DS_FIND_CHILDREN) != 0);
1716                 if (rv)
1717                         spa_set_log_state(spa, SPA_LOG_MISSING);
1718                 break;
1719         }
1720         return (rv);
1721 }
1722 
1723 static boolean_t
1724 spa_passivate_log(spa_t *spa)
1725 {
1726         vdev_t *rvd = spa->spa_root_vdev;
1727         boolean_t slog_found = B_FALSE;
1728 
1729         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1730 
1731         if (!spa_has_slogs(spa))
1732                 return (B_FALSE);
1733 
1734         for (int c = 0; c < rvd->vdev_children; c++) {
1735                 vdev_t *tvd = rvd->vdev_child[c];
1736                 metaslab_group_t *mg = tvd->vdev_mg;
1737 
1738                 if (tvd->vdev_islog) {
1739                         metaslab_group_passivate(mg);
1740                         slog_found = B_TRUE;
1741                 }
1742         }
1743 
1744         return (slog_found);
1745 }
1746 
1747 static void
1748 spa_activate_log(spa_t *spa)
1749 {
1750         vdev_t *rvd = spa->spa_root_vdev;
1751 
1752         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1753 
1754         for (int c = 0; c < rvd->vdev_children; c++) {
1755                 vdev_t *tvd = rvd->vdev_child[c];
1756                 metaslab_group_t *mg = tvd->vdev_mg;
1757 
1758                 if (tvd->vdev_islog)
1759                         metaslab_group_activate(mg);
1760         }
1761 }
1762 
1763 int
1764 spa_offline_log(spa_t *spa)
1765 {
1766         int error;
1767 
1768         error = dmu_objset_find(spa_name(spa), zil_vdev_offline,
1769             NULL, DS_FIND_CHILDREN);
1770         if (error == 0) {
1771                 /*
1772                  * We successfully offlined the log device, sync out the
1773                  * current txg so that the "stubby" block can be removed
1774                  * by zil_sync().
1775                  */
1776                 txg_wait_synced(spa->spa_dsl_pool, 0);
1777         }
1778         return (error);
1779 }
1780 
1781 static void
1782 spa_aux_check_removed(spa_aux_vdev_t *sav)
1783 {
1784         for (int i = 0; i < sav->sav_count; i++)
1785                 spa_check_removed(sav->sav_vdevs[i]);
1786 }
1787 
1788 void
1789 spa_claim_notify(zio_t *zio)
1790 {
1791         spa_t *spa = zio->io_spa;
1792 
1793         if (zio->io_error)
1794                 return;
1795 
1796         mutex_enter(&spa->spa_props_lock);       /* any mutex will do */
1797         if (spa->spa_claim_max_txg < zio->io_bp->blk_birth)
1798                 spa->spa_claim_max_txg = zio->io_bp->blk_birth;
1799         mutex_exit(&spa->spa_props_lock);
1800 }
1801 
1802 typedef struct spa_load_error {
1803         uint64_t        sle_meta_count;
1804         uint64_t        sle_data_count;
1805 } spa_load_error_t;
1806 
1807 static void
1808 spa_load_verify_done(zio_t *zio)
1809 {
1810         blkptr_t *bp = zio->io_bp;
1811         spa_load_error_t *sle = zio->io_private;
1812         dmu_object_type_t type = BP_GET_TYPE(bp);
1813         int error = zio->io_error;
1814 
1815         if (error) {
1816                 if ((BP_GET_LEVEL(bp) != 0 || DMU_OT_IS_METADATA(type)) &&
1817                     type != DMU_OT_INTENT_LOG)
1818                         atomic_add_64(&sle->sle_meta_count, 1);
1819                 else
1820                         atomic_add_64(&sle->sle_data_count, 1);
1821         }
1822         zio_data_buf_free(zio->io_data, zio->io_size);
1823 }
1824 
1825 /*ARGSUSED*/
1826 static int
1827 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1828     const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1829 {
1830         if (bp != NULL) {
1831                 zio_t *rio = arg;
1832                 size_t size = BP_GET_PSIZE(bp);
1833                 void *data = zio_data_buf_alloc(size);
1834 
1835                 zio_nowait(zio_read(rio, spa, bp, data, size,
1836                     spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
1837                     ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
1838                     ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
1839         }
1840         return (0);
1841 }
1842 
1843 static int
1844 spa_load_verify(spa_t *spa)
1845 {
1846         zio_t *rio;
1847         spa_load_error_t sle = { 0 };
1848         zpool_rewind_policy_t policy;
1849         boolean_t verify_ok = B_FALSE;
1850         int error;
1851 
1852         zpool_get_rewind_policy(spa->spa_config, &policy);
1853 
1854         if (policy.zrp_request & ZPOOL_NEVER_REWIND)
1855                 return (0);
1856 
1857         rio = zio_root(spa, NULL, &sle,
1858             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1859 
1860         error = traverse_pool(spa, spa->spa_verify_min_txg,
1861             TRAVERSE_PRE | TRAVERSE_PREFETCH, spa_load_verify_cb, rio);
1862 
1863         (void) zio_wait(rio);
1864 
1865         spa->spa_load_meta_errors = sle.sle_meta_count;
1866         spa->spa_load_data_errors = sle.sle_data_count;
1867 
1868         if (!error && sle.sle_meta_count <= policy.zrp_maxmeta &&
1869             sle.sle_data_count <= policy.zrp_maxdata) {
1870                 int64_t loss = 0;
1871 
1872                 verify_ok = B_TRUE;
1873                 spa->spa_load_txg = spa->spa_uberblock.ub_txg;
1874                 spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
1875 
1876                 loss = spa->spa_last_ubsync_txg_ts - spa->spa_load_txg_ts;
1877                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1878                     ZPOOL_CONFIG_LOAD_TIME, spa->spa_load_txg_ts) == 0);
1879                 VERIFY(nvlist_add_int64(spa->spa_load_info,
1880                     ZPOOL_CONFIG_REWIND_TIME, loss) == 0);
1881                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1882                     ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count) == 0);
1883         } else {
1884                 spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
1885         }
1886 
1887         if (error) {
1888                 if (error != ENXIO && error != EIO)
1889                         error = SET_ERROR(EIO);
1890                 return (error);
1891         }
1892 
1893         return (verify_ok ? 0 : EIO);
1894 }
1895 
1896 /*
1897  * Find a value in the pool props object.
1898  */
1899 static void
1900 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
1901 {
1902         (void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
1903             zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
1904 }
1905 
1906 /*
1907  * Find a value in the pool directory object.
1908  */
1909 static int
1910 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val)
1911 {
1912         return (zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1913             name, sizeof (uint64_t), 1, val));
1914 }
1915 
1916 static int
1917 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
1918 {
1919         vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
1920         return (err);
1921 }
1922 
1923 /*
1924  * Fix up config after a partly-completed split.  This is done with the
1925  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
1926  * pool have that entry in their config, but only the splitting one contains
1927  * a list of all the guids of the vdevs that are being split off.
1928  *
1929  * This function determines what to do with that list: either rejoin
1930  * all the disks to the pool, or complete the splitting process.  To attempt
1931  * the rejoin, each disk that is offlined is marked online again, and
1932  * we do a reopen() call.  If the vdev label for every disk that was
1933  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
1934  * then we call vdev_split() on each disk, and complete the split.
1935  *
1936  * Otherwise we leave the config alone, with all the vdevs in place in
1937  * the original pool.
1938  */
1939 static void
1940 spa_try_repair(spa_t *spa, nvlist_t *config)
1941 {
1942         uint_t extracted;
1943         uint64_t *glist;
1944         uint_t i, gcount;
1945         nvlist_t *nvl;
1946         vdev_t **vd;
1947         boolean_t attempt_reopen;
1948 
1949         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
1950                 return;
1951 
1952         /* check that the config is complete */
1953         if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
1954             &glist, &gcount) != 0)
1955                 return;
1956 
1957         vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
1958 
1959         /* attempt to online all the vdevs & validate */
1960         attempt_reopen = B_TRUE;
1961         for (i = 0; i < gcount; i++) {
1962                 if (glist[i] == 0)      /* vdev is hole */
1963                         continue;
1964 
1965                 vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
1966                 if (vd[i] == NULL) {
1967                         /*
1968                          * Don't bother attempting to reopen the disks;
1969                          * just do the split.
1970                          */
1971                         attempt_reopen = B_FALSE;
1972                 } else {
1973                         /* attempt to re-online it */
1974                         vd[i]->vdev_offline = B_FALSE;
1975                 }
1976         }
1977 
1978         if (attempt_reopen) {
1979                 vdev_reopen(spa->spa_root_vdev);
1980 
1981                 /* check each device to see what state it's in */
1982                 for (extracted = 0, i = 0; i < gcount; i++) {
1983                         if (vd[i] != NULL &&
1984                             vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
1985                                 break;
1986                         ++extracted;
1987                 }
1988         }
1989 
1990         /*
1991          * If every disk has been moved to the new pool, or if we never
1992          * even attempted to look at them, then we split them off for
1993          * good.
1994          */
1995         if (!attempt_reopen || gcount == extracted) {
1996                 for (i = 0; i < gcount; i++)
1997                         if (vd[i] != NULL)
1998                                 vdev_split(vd[i]);
1999                 vdev_reopen(spa->spa_root_vdev);
2000         }
2001 
2002         kmem_free(vd, gcount * sizeof (vdev_t *));
2003 }
2004 
2005 static int
2006 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
2007     boolean_t mosconfig)
2008 {
2009         nvlist_t *config = spa->spa_config;
2010         char *ereport = FM_EREPORT_ZFS_POOL;
2011         char *comment;
2012         int error;
2013         uint64_t pool_guid;
2014         nvlist_t *nvl;
2015 
2016         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
2017                 return (SET_ERROR(EINVAL));
2018 
2019         ASSERT(spa->spa_comment == NULL);
2020         if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
2021                 spa->spa_comment = spa_strdup(comment);
2022 
2023         /*
2024          * Versioning wasn't explicitly added to the label until later, so if
2025          * it's not present treat it as the initial version.
2026          */
2027         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
2028             &spa->spa_ubsync.ub_version) != 0)
2029                 spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
2030 
2031         (void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
2032             &spa->spa_config_txg);
2033 
2034         if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
2035             spa_guid_exists(pool_guid, 0)) {
2036                 error = SET_ERROR(EEXIST);
2037         } else {
2038                 spa->spa_config_guid = pool_guid;
2039 
2040                 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT,
2041                     &nvl) == 0) {
2042                         VERIFY(nvlist_dup(nvl, &spa->spa_config_splitting,
2043                             KM_SLEEP) == 0);
2044                 }
2045 
2046                 nvlist_free(spa->spa_load_info);
2047                 spa->spa_load_info = fnvlist_alloc();
2048 
2049                 gethrestime(&spa->spa_loaded_ts);
2050                 error = spa_load_impl(spa, pool_guid, config, state, type,
2051                     mosconfig, &ereport);
2052         }
2053 
2054         spa->spa_minref = refcount_count(&spa->spa_refcount);
2055         if (error) {
2056                 if (error != EEXIST) {
2057                         spa->spa_loaded_ts.tv_sec = 0;
2058                         spa->spa_loaded_ts.tv_nsec = 0;
2059                 }
2060                 if (error != EBADF) {
2061                         zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
2062                 }
2063         }
2064         spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
2065         spa->spa_ena = 0;
2066 
2067         return (error);
2068 }
2069 
2070 /*
2071  * Load an existing storage pool, using the pool's builtin spa_config as a
2072  * source of configuration information.
2073  */
2074 static int
2075 spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config,
2076     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
2077     char **ereport)
2078 {
2079         int error = 0;
2080         nvlist_t *nvroot = NULL;
2081         nvlist_t *label;
2082         vdev_t *rvd;
2083         uberblock_t *ub = &spa->spa_uberblock;
2084         uint64_t children, config_cache_txg = spa->spa_config_txg;
2085         int orig_mode = spa->spa_mode;
2086         int parse;
2087         uint64_t obj;
2088         boolean_t missing_feat_write = B_FALSE;
2089 
2090         /*
2091          * If this is an untrusted config, access the pool in read-only mode.
2092          * This prevents things like resilvering recently removed devices.
2093          */
2094         if (!mosconfig)
2095                 spa->spa_mode = FREAD;
2096 
2097         ASSERT(MUTEX_HELD(&spa_namespace_lock));
2098 
2099         spa->spa_load_state = state;
2100 
2101         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot))
2102                 return (SET_ERROR(EINVAL));
2103 
2104         parse = (type == SPA_IMPORT_EXISTING ?
2105             VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
2106 
2107         /*
2108          * Create "The Godfather" zio to hold all async IOs
2109          */
2110         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
2111             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
2112 
2113         /*
2114          * Parse the configuration into a vdev tree.  We explicitly set the
2115          * value that will be returned by spa_version() since parsing the
2116          * configuration requires knowing the version number.
2117          */
2118         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2119         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, parse);
2120         spa_config_exit(spa, SCL_ALL, FTAG);
2121 
2122         if (error != 0)
2123                 return (error);
2124 
2125         ASSERT(spa->spa_root_vdev == rvd);
2126 
2127         if (type != SPA_IMPORT_ASSEMBLE) {
2128                 ASSERT(spa_guid(spa) == pool_guid);
2129         }
2130 
2131         /*
2132          * Try to open all vdevs, loading each label in the process.
2133          */
2134         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2135         error = vdev_open(rvd);
2136         spa_config_exit(spa, SCL_ALL, FTAG);
2137         if (error != 0)
2138                 return (error);
2139 
2140         /*
2141          * We need to validate the vdev labels against the configuration that
2142          * we have in hand, which is dependent on the setting of mosconfig. If
2143          * mosconfig is true then we're validating the vdev labels based on
2144          * that config.  Otherwise, we're validating against the cached config
2145          * (zpool.cache) that was read when we loaded the zfs module, and then
2146          * later we will recursively call spa_load() and validate against
2147          * the vdev config.
2148          *
2149          * If we're assembling a new pool that's been split off from an
2150          * existing pool, the labels haven't yet been updated so we skip
2151          * validation for now.
2152          */
2153         if (type != SPA_IMPORT_ASSEMBLE) {
2154                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2155                 error = vdev_validate(rvd, mosconfig);
2156                 spa_config_exit(spa, SCL_ALL, FTAG);
2157 
2158                 if (error != 0)
2159                         return (error);
2160 
2161                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2162                         return (SET_ERROR(ENXIO));
2163         }
2164 
2165         /*
2166          * Find the best uberblock.
2167          */
2168         vdev_uberblock_load(rvd, ub, &label);
2169 
2170         /*
2171          * If we weren't able to find a single valid uberblock, return failure.
2172          */
2173         if (ub->ub_txg == 0) {
2174                 nvlist_free(label);
2175                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
2176         }
2177 
2178         /*
2179          * If the pool has an unsupported version we can't open it.
2180          */
2181         if (!SPA_VERSION_IS_SUPPORTED(ub->ub_version)) {
2182                 nvlist_free(label);
2183                 return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
2184         }
2185 
2186         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2187                 nvlist_t *features;
2188 
2189                 /*
2190                  * If we weren't able to find what's necessary for reading the
2191                  * MOS in the label, return failure.
2192                  */
2193                 if (label == NULL || nvlist_lookup_nvlist(label,
2194                     ZPOOL_CONFIG_FEATURES_FOR_READ, &features) != 0) {
2195                         nvlist_free(label);
2196                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2197                             ENXIO));
2198                 }
2199 
2200                 /*
2201                  * Update our in-core representation with the definitive values
2202                  * from the label.
2203                  */
2204                 nvlist_free(spa->spa_label_features);
2205                 VERIFY(nvlist_dup(features, &spa->spa_label_features, 0) == 0);
2206         }
2207 
2208         nvlist_free(label);
2209 
2210         /*
2211          * Look through entries in the label nvlist's features_for_read. If
2212          * there is a feature listed there which we don't understand then we
2213          * cannot open a pool.
2214          */
2215         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2216                 nvlist_t *unsup_feat;
2217 
2218                 VERIFY(nvlist_alloc(&unsup_feat, NV_UNIQUE_NAME, KM_SLEEP) ==
2219                     0);
2220 
2221                 for (nvpair_t *nvp = nvlist_next_nvpair(spa->spa_label_features,
2222                     NULL); nvp != NULL;
2223                     nvp = nvlist_next_nvpair(spa->spa_label_features, nvp)) {
2224                         if (!zfeature_is_supported(nvpair_name(nvp))) {
2225                                 VERIFY(nvlist_add_string(unsup_feat,
2226                                     nvpair_name(nvp), "") == 0);
2227                         }
2228                 }
2229 
2230                 if (!nvlist_empty(unsup_feat)) {
2231                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
2232                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat) == 0);
2233                         nvlist_free(unsup_feat);
2234                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2235                             ENOTSUP));
2236                 }
2237 
2238                 nvlist_free(unsup_feat);
2239         }
2240 
2241         /*
2242          * If the vdev guid sum doesn't match the uberblock, we have an
2243          * incomplete configuration.  We first check to see if the pool
2244          * is aware of the complete config (i.e ZPOOL_CONFIG_VDEV_CHILDREN).
2245          * If it is, defer the vdev_guid_sum check till later so we
2246          * can handle missing vdevs.
2247          */
2248         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN,
2249             &children) != 0 && mosconfig && type != SPA_IMPORT_ASSEMBLE &&
2250             rvd->vdev_guid_sum != ub->ub_guid_sum)
2251                 return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
2252 
2253         if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
2254                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2255                 spa_try_repair(spa, config);
2256                 spa_config_exit(spa, SCL_ALL, FTAG);
2257                 nvlist_free(spa->spa_config_splitting);
2258                 spa->spa_config_splitting = NULL;
2259         }
2260 
2261         /*
2262          * Initialize internal SPA structures.
2263          */
2264         spa->spa_state = POOL_STATE_ACTIVE;
2265         spa->spa_ubsync = spa->spa_uberblock;
2266         spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
2267             TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
2268         spa->spa_first_txg = spa->spa_last_ubsync_txg ?
2269             spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
2270         spa->spa_claim_max_txg = spa->spa_first_txg;
2271         spa->spa_prev_software_version = ub->ub_software_version;
2272 
2273         error = dsl_pool_init(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
2274         if (error)
2275                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2276         spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
2277 
2278         if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object) != 0)
2279                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2280 
2281         if (spa_version(spa) >= SPA_VERSION_FEATURES) {
2282                 boolean_t missing_feat_read = B_FALSE;
2283                 nvlist_t *unsup_feat, *enabled_feat;
2284 
2285                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_READ,
2286                     &spa->spa_feat_for_read_obj) != 0) {
2287                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2288                 }
2289 
2290                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_WRITE,
2291                     &spa->spa_feat_for_write_obj) != 0) {
2292                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2293                 }
2294 
2295                 if (spa_dir_prop(spa, DMU_POOL_FEATURE_DESCRIPTIONS,
2296                     &spa->spa_feat_desc_obj) != 0) {
2297                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2298                 }
2299 
2300                 enabled_feat = fnvlist_alloc();
2301                 unsup_feat = fnvlist_alloc();
2302 
2303                 if (!spa_features_check(spa, B_FALSE,
2304                     unsup_feat, enabled_feat))
2305                         missing_feat_read = B_TRUE;
2306 
2307                 if (spa_writeable(spa) || state == SPA_LOAD_TRYIMPORT) {
2308                         if (!spa_features_check(spa, B_TRUE,
2309                             unsup_feat, enabled_feat)) {
2310                                 missing_feat_write = B_TRUE;
2311                         }
2312                 }
2313 
2314                 fnvlist_add_nvlist(spa->spa_load_info,
2315                     ZPOOL_CONFIG_ENABLED_FEAT, enabled_feat);
2316 
2317                 if (!nvlist_empty(unsup_feat)) {
2318                         fnvlist_add_nvlist(spa->spa_load_info,
2319                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
2320                 }
2321 
2322                 fnvlist_free(enabled_feat);
2323                 fnvlist_free(unsup_feat);
2324 
2325                 if (!missing_feat_read) {
2326                         fnvlist_add_boolean(spa->spa_load_info,
2327                             ZPOOL_CONFIG_CAN_RDONLY);
2328                 }
2329 
2330                 /*
2331                  * If the state is SPA_LOAD_TRYIMPORT, our objective is
2332                  * twofold: to determine whether the pool is available for
2333                  * import in read-write mode and (if it is not) whether the
2334                  * pool is available for import in read-only mode. If the pool
2335                  * is available for import in read-write mode, it is displayed
2336                  * as available in userland; if it is not available for import
2337                  * in read-only mode, it is displayed as unavailable in
2338                  * userland. If the pool is available for import in read-only
2339                  * mode but not read-write mode, it is displayed as unavailable
2340                  * in userland with a special note that the pool is actually
2341                  * available for open in read-only mode.
2342                  *
2343                  * As a result, if the state is SPA_LOAD_TRYIMPORT and we are
2344                  * missing a feature for write, we must first determine whether
2345                  * the pool can be opened read-only before returning to
2346                  * userland in order to know whether to display the
2347                  * abovementioned note.
2348                  */
2349                 if (missing_feat_read || (missing_feat_write &&
2350                     spa_writeable(spa))) {
2351                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2352                             ENOTSUP));
2353                 }
2354         }
2355 
2356         spa->spa_is_initializing = B_TRUE;
2357         error = dsl_pool_open(spa->spa_dsl_pool);
2358         spa->spa_is_initializing = B_FALSE;
2359         if (error != 0)
2360                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2361 
2362         if (!mosconfig) {
2363                 uint64_t hostid;
2364                 nvlist_t *policy = NULL, *nvconfig;
2365 
2366                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2367                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2368 
2369                 if (!spa_is_root(spa) && nvlist_lookup_uint64(nvconfig,
2370                     ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
2371                         char *hostname;
2372                         unsigned long myhostid = 0;
2373 
2374                         VERIFY(nvlist_lookup_string(nvconfig,
2375                             ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
2376 
2377 #ifdef  _KERNEL
2378                         myhostid = zone_get_hostid(NULL);
2379 #else   /* _KERNEL */
2380                         /*
2381                          * We're emulating the system's hostid in userland, so
2382                          * we can't use zone_get_hostid().
2383                          */
2384                         (void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
2385 #endif  /* _KERNEL */
2386                         if (hostid != 0 && myhostid != 0 &&
2387                             hostid != myhostid) {
2388                                 nvlist_free(nvconfig);
2389                                 cmn_err(CE_WARN, "pool '%s' could not be "
2390                                     "loaded as it was last accessed by "
2391                                     "another system (host: %s hostid: 0x%lx). "
2392                                     "See: http://illumos.org/msg/ZFS-8000-EY",
2393                                     spa_name(spa), hostname,
2394                                     (unsigned long)hostid);
2395                                 return (SET_ERROR(EBADF));
2396                         }
2397                 }
2398                 if (nvlist_lookup_nvlist(spa->spa_config,
2399                     ZPOOL_REWIND_POLICY, &policy) == 0)
2400                         VERIFY(nvlist_add_nvlist(nvconfig,
2401                             ZPOOL_REWIND_POLICY, policy) == 0);
2402 
2403                 spa_config_set(spa, nvconfig);
2404                 spa_unload(spa);
2405                 spa_deactivate(spa);
2406                 spa_activate(spa, orig_mode);
2407 
2408                 return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
2409         }
2410 
2411         if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj) != 0)
2412                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2413         error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
2414         if (error != 0)
2415                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2416 
2417         /*
2418          * Load the bit that tells us to use the new accounting function
2419          * (raid-z deflation).  If we have an older pool, this will not
2420          * be present.
2421          */
2422         error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate);
2423         if (error != 0 && error != ENOENT)
2424                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2425 
2426         error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
2427             &spa->spa_creation_version);
2428         if (error != 0 && error != ENOENT)
2429                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2430 
2431         /*
2432          * Load the persistent error log.  If we have an older pool, this will
2433          * not be present.
2434          */
2435         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last);
2436         if (error != 0 && error != ENOENT)
2437                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2438 
2439         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
2440             &spa->spa_errlog_scrub);
2441         if (error != 0 && error != ENOENT)
2442                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2443 
2444         /*
2445          * Load the history object.  If we have an older pool, this
2446          * will not be present.
2447          */
2448         error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history);
2449         if (error != 0 && error != ENOENT)
2450                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2451 
2452         /*
2453          * If we're assembling the pool from the split-off vdevs of
2454          * an existing pool, we don't want to attach the spares & cache
2455          * devices.
2456          */
2457 
2458         /*
2459          * Load any hot spares for this pool.
2460          */
2461         error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object);
2462         if (error != 0 && error != ENOENT)
2463                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2464         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2465                 ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
2466                 if (load_nvlist(spa, spa->spa_spares.sav_object,
2467                     &spa->spa_spares.sav_config) != 0)
2468                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2469 
2470                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2471                 spa_load_spares(spa);
2472                 spa_config_exit(spa, SCL_ALL, FTAG);
2473         } else if (error == 0) {
2474                 spa->spa_spares.sav_sync = B_TRUE;
2475         }
2476 
2477         /*
2478          * Load any level 2 ARC devices for this pool.
2479          */
2480         error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
2481             &spa->spa_l2cache.sav_object);
2482         if (error != 0 && error != ENOENT)
2483                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2484         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2485                 ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
2486                 if (load_nvlist(spa, spa->spa_l2cache.sav_object,
2487                     &spa->spa_l2cache.sav_config) != 0)
2488                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2489 
2490                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2491                 spa_load_l2cache(spa);
2492                 spa_config_exit(spa, SCL_ALL, FTAG);
2493         } else if (error == 0) {
2494                 spa->spa_l2cache.sav_sync = B_TRUE;
2495         }
2496 
2497         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2498 
2499         error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object);
2500         if (error && error != ENOENT)
2501                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2502 
2503         if (error == 0) {
2504                 uint64_t autoreplace;
2505 
2506                 spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
2507                 spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
2508                 spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
2509                 spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
2510                 spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
2511                 spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
2512                     &spa->spa_dedup_ditto);
2513 
2514                 spa->spa_autoreplace = (autoreplace != 0);
2515         }
2516 
2517         /*
2518          * If the 'autoreplace' property is set, then post a resource notifying
2519          * the ZFS DE that it should not issue any faults for unopenable
2520          * devices.  We also iterate over the vdevs, and post a sysevent for any
2521          * unopenable vdevs so that the normal autoreplace handler can take
2522          * over.
2523          */
2524         if (spa->spa_autoreplace && state != SPA_LOAD_TRYIMPORT) {
2525                 spa_check_removed(spa->spa_root_vdev);
2526                 /*
2527                  * For the import case, this is done in spa_import(), because
2528                  * at this point we're using the spare definitions from
2529                  * the MOS config, not necessarily from the userland config.
2530                  */
2531                 if (state != SPA_LOAD_IMPORT) {
2532                         spa_aux_check_removed(&spa->spa_spares);
2533                         spa_aux_check_removed(&spa->spa_l2cache);
2534                 }
2535         }
2536 
2537         /*
2538          * Load the vdev state for all toplevel vdevs.
2539          */
2540         vdev_load(rvd);
2541 
2542         /*
2543          * Propagate the leaf DTLs we just loaded all the way up the tree.
2544          */
2545         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2546         vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
2547         spa_config_exit(spa, SCL_ALL, FTAG);
2548 
2549         /*
2550          * Load the DDTs (dedup tables).
2551          */
2552         error = ddt_load(spa);
2553         if (error != 0)
2554                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2555 
2556         spa_update_dspace(spa);
2557 
2558         /*
2559          * Validate the config, using the MOS config to fill in any
2560          * information which might be missing.  If we fail to validate
2561          * the config then declare the pool unfit for use. If we're
2562          * assembling a pool from a split, the log is not transferred
2563          * over.
2564          */
2565         if (type != SPA_IMPORT_ASSEMBLE) {
2566                 nvlist_t *nvconfig;
2567 
2568                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2569                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2570 
2571                 if (!spa_config_valid(spa, nvconfig)) {
2572                         nvlist_free(nvconfig);
2573                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
2574                             ENXIO));
2575                 }
2576                 nvlist_free(nvconfig);
2577 
2578                 /*
2579                  * Now that we've validated the config, check the state of the
2580                  * root vdev.  If it can't be opened, it indicates one or
2581                  * more toplevel vdevs are faulted.
2582                  */
2583                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2584                         return (SET_ERROR(ENXIO));
2585 
2586                 if (spa_check_logs(spa)) {
2587                         *ereport = FM_EREPORT_ZFS_LOG_REPLAY;
2588                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG, ENXIO));
2589                 }
2590         }
2591 
2592         if (missing_feat_write) {
2593                 ASSERT(state == SPA_LOAD_TRYIMPORT);
2594 
2595                 /*
2596                  * At this point, we know that we can open the pool in
2597                  * read-only mode but not read-write mode. We now have enough
2598                  * information and can return to userland.
2599                  */
2600                 return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT, ENOTSUP));
2601         }
2602 
2603         /*
2604          * We've successfully opened the pool, verify that we're ready
2605          * to start pushing transactions.
2606          */
2607         if (state != SPA_LOAD_TRYIMPORT) {
2608                 if (error = spa_load_verify(spa))
2609                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2610                             error));
2611         }
2612 
2613         if (spa_writeable(spa) && (state == SPA_LOAD_RECOVER ||
2614             spa->spa_load_max_txg == UINT64_MAX)) {
2615                 dmu_tx_t *tx;
2616                 int need_update = B_FALSE;
2617 
2618                 ASSERT(state != SPA_LOAD_TRYIMPORT);
2619 
2620                 /*
2621                  * Claim log blocks that haven't been committed yet.
2622                  * This must all happen in a single txg.
2623                  * Note: spa_claim_max_txg is updated by spa_claim_notify(),
2624                  * invoked from zil_claim_log_block()'s i/o done callback.
2625                  * Price of rollback is that we abandon the log.
2626                  */
2627                 spa->spa_claiming = B_TRUE;
2628 
2629                 tx = dmu_tx_create_assigned(spa_get_dsl(spa),
2630                     spa_first_txg(spa));
2631                 (void) dmu_objset_find(spa_name(spa),
2632                     zil_claim, tx, DS_FIND_CHILDREN);
2633                 dmu_tx_commit(tx);
2634 
2635                 spa->spa_claiming = B_FALSE;
2636 
2637                 spa_set_log_state(spa, SPA_LOG_GOOD);
2638                 spa->spa_sync_on = B_TRUE;
2639                 txg_sync_start(spa->spa_dsl_pool);
2640 
2641                 /*
2642                  * Wait for all claims to sync.  We sync up to the highest
2643                  * claimed log block birth time so that claimed log blocks
2644                  * don't appear to be from the future.  spa_claim_max_txg
2645                  * will have been set for us by either zil_check_log_chain()
2646                  * (invoked from spa_check_logs()) or zil_claim() above.
2647                  */
2648                 txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
2649 
2650                 /*
2651                  * If the config cache is stale, or we have uninitialized
2652                  * metaslabs (see spa_vdev_add()), then update the config.
2653                  *
2654                  * If this is a verbatim import, trust the current
2655                  * in-core spa_config and update the disk labels.
2656                  */
2657                 if (config_cache_txg != spa->spa_config_txg ||
2658                     state == SPA_LOAD_IMPORT ||
2659                     state == SPA_LOAD_RECOVER ||
2660                     (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
2661                         need_update = B_TRUE;
2662 
2663                 for (int c = 0; c < rvd->vdev_children; c++)
2664                         if (rvd->vdev_child[c]->vdev_ms_array == 0)
2665                                 need_update = B_TRUE;
2666 
2667                 /*
2668                  * Update the config cache asychronously in case we're the
2669                  * root pool, in which case the config cache isn't writable yet.
2670                  */
2671                 if (need_update)
2672                         spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2673 
2674                 /*
2675                  * Check all DTLs to see if anything needs resilvering.
2676                  */
2677                 if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
2678                     vdev_resilver_needed(rvd, NULL, NULL))
2679                         spa_async_request(spa, SPA_ASYNC_RESILVER);
2680 
2681                 /*
2682                  * Log the fact that we booted up (so that we can detect if
2683                  * we rebooted in the middle of an operation).
2684                  */
2685                 spa_history_log_version(spa, "open");
2686 
2687                 /*
2688                  * Delete any inconsistent datasets.
2689                  */
2690                 (void) dmu_objset_find(spa_name(spa),
2691                     dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
2692 
2693                 /*
2694                  * Clean up any stale temporary dataset userrefs.
2695                  */
2696                 dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
2697         }
2698 
2699         return (0);
2700 }
2701 
2702 static int
2703 spa_load_retry(spa_t *spa, spa_load_state_t state, int mosconfig)
2704 {
2705         int mode = spa->spa_mode;
2706 
2707         spa_unload(spa);
2708         spa_deactivate(spa);
2709 
2710         spa->spa_load_max_txg--;
2711 
2712         spa_activate(spa, mode);
2713         spa_async_suspend(spa);
2714 
2715         return (spa_load(spa, state, SPA_IMPORT_EXISTING, mosconfig));
2716 }
2717 
2718 /*
2719  * If spa_load() fails this function will try loading prior txg's. If
2720  * 'state' is SPA_LOAD_RECOVER and one of these loads succeeds the pool
2721  * will be rewound to that txg. If 'state' is not SPA_LOAD_RECOVER this
2722  * function will not rewind the pool and will return the same error as
2723  * spa_load().
2724  */
2725 static int
2726 spa_load_best(spa_t *spa, spa_load_state_t state, int mosconfig,
2727     uint64_t max_request, int rewind_flags)
2728 {
2729         nvlist_t *loadinfo = NULL;
2730         nvlist_t *config = NULL;
2731         int load_error, rewind_error;
2732         uint64_t safe_rewind_txg;
2733         uint64_t min_txg;
2734 
2735         if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
2736                 spa->spa_load_max_txg = spa->spa_load_txg;
2737                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2738         } else {
2739                 spa->spa_load_max_txg = max_request;
2740         }
2741 
2742         load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING,
2743             mosconfig);
2744         if (load_error == 0)
2745                 return (0);
2746 
2747         if (spa->spa_root_vdev != NULL)
2748                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2749 
2750         spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
2751         spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
2752 
2753         if (rewind_flags & ZPOOL_NEVER_REWIND) {
2754                 nvlist_free(config);
2755                 return (load_error);
2756         }
2757 
2758         if (state == SPA_LOAD_RECOVER) {
2759                 /* Price of rolling back is discarding txgs, including log */
2760                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2761         } else {
2762                 /*
2763                  * If we aren't rolling back save the load info from our first
2764                  * import attempt so that we can restore it after attempting
2765                  * to rewind.
2766                  */
2767                 loadinfo = spa->spa_load_info;
2768                 spa->spa_load_info = fnvlist_alloc();
2769         }
2770 
2771         spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
2772         safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
2773         min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
2774             TXG_INITIAL : safe_rewind_txg;
2775 
2776         /*
2777          * Continue as long as we're finding errors, we're still within
2778          * the acceptable rewind range, and we're still finding uberblocks
2779          */
2780         while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
2781             spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
2782                 if (spa->spa_load_max_txg < safe_rewind_txg)
2783                         spa->spa_extreme_rewind = B_TRUE;
2784                 rewind_error = spa_load_retry(spa, state, mosconfig);
2785         }
2786 
2787         spa->spa_extreme_rewind = B_FALSE;
2788         spa->spa_load_max_txg = UINT64_MAX;
2789 
2790         if (config && (rewind_error || state != SPA_LOAD_RECOVER))
2791                 spa_config_set(spa, config);
2792 
2793         if (state == SPA_LOAD_RECOVER) {
2794                 ASSERT3P(loadinfo, ==, NULL);
2795                 return (rewind_error);
2796         } else {
2797                 /* Store the rewind info as part of the initial load info */
2798                 fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
2799                     spa->spa_load_info);
2800 
2801                 /* Restore the initial load info */
2802                 fnvlist_free(spa->spa_load_info);
2803                 spa->spa_load_info = loadinfo;
2804 
2805                 return (load_error);
2806         }
2807 }
2808 
2809 /*
2810  * Pool Open/Import
2811  *
2812  * The import case is identical to an open except that the configuration is sent
2813  * down from userland, instead of grabbed from the configuration cache.  For the
2814  * case of an open, the pool configuration will exist in the
2815  * POOL_STATE_UNINITIALIZED state.
2816  *
2817  * The stats information (gen/count/ustats) is used to gather vdev statistics at
2818  * the same time open the pool, without having to keep around the spa_t in some
2819  * ambiguous state.
2820  */
2821 static int
2822 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
2823     nvlist_t **config)
2824 {
2825         spa_t *spa;
2826         spa_load_state_t state = SPA_LOAD_OPEN;
2827         int error;
2828         int locked = B_FALSE;
2829 
2830         *spapp = NULL;
2831 
2832         /*
2833          * As disgusting as this is, we need to support recursive calls to this
2834          * function because dsl_dir_open() is called during spa_load(), and ends
2835          * up calling spa_open() again.  The real fix is to figure out how to
2836          * avoid dsl_dir_open() calling this in the first place.
2837          */
2838         if (mutex_owner(&spa_namespace_lock) != curthread) {
2839                 mutex_enter(&spa_namespace_lock);
2840                 locked = B_TRUE;
2841         }
2842 
2843         if ((spa = spa_lookup(pool)) == NULL) {
2844                 if (locked)
2845                         mutex_exit(&spa_namespace_lock);
2846                 return (SET_ERROR(ENOENT));
2847         }
2848 
2849         if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
2850                 zpool_rewind_policy_t policy;
2851 
2852                 zpool_get_rewind_policy(nvpolicy ? nvpolicy : spa->spa_config,
2853                     &policy);
2854                 if (policy.zrp_request & ZPOOL_DO_REWIND)
2855                         state = SPA_LOAD_RECOVER;
2856 
2857                 spa_activate(spa, spa_mode_global);
2858 
2859                 if (state != SPA_LOAD_RECOVER)
2860                         spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
2861 
2862                 error = spa_load_best(spa, state, B_FALSE, policy.zrp_txg,
2863                     policy.zrp_request);
2864 
2865                 if (error == EBADF) {
2866                         /*
2867                          * If vdev_validate() returns failure (indicated by
2868                          * EBADF), it indicates that one of the vdevs indicates
2869                          * that the pool has been exported or destroyed.  If
2870                          * this is the case, the config cache is out of sync and
2871                          * we should remove the pool from the namespace.
2872                          */
2873                         spa_unload(spa);
2874                         spa_deactivate(spa);
2875                         spa_config_sync(spa, B_TRUE, B_TRUE);
2876                         spa_remove(spa);
2877                         if (locked)
2878                                 mutex_exit(&spa_namespace_lock);
2879                         return (SET_ERROR(ENOENT));
2880                 }
2881 
2882                 if (error) {
2883                         /*
2884                          * We can't open the pool, but we still have useful
2885                          * information: the state of each vdev after the
2886                          * attempted vdev_open().  Return this to the user.
2887                          */
2888                         if (config != NULL && spa->spa_config) {
2889                                 VERIFY(nvlist_dup(spa->spa_config, config,
2890                                     KM_SLEEP) == 0);
2891                                 VERIFY(nvlist_add_nvlist(*config,
2892                                     ZPOOL_CONFIG_LOAD_INFO,
2893                                     spa->spa_load_info) == 0);
2894                         }
2895                         spa_unload(spa);
2896                         spa_deactivate(spa);
2897                         spa->spa_last_open_failed = error;
2898                         if (locked)
2899                                 mutex_exit(&spa_namespace_lock);
2900                         *spapp = NULL;
2901                         return (error);
2902                 }
2903         }
2904 
2905         spa_open_ref(spa, tag);
2906 
2907         if (config != NULL)
2908                 *config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2909 
2910         /*
2911          * If we've recovered the pool, pass back any information we
2912          * gathered while doing the load.
2913          */
2914         if (state == SPA_LOAD_RECOVER) {
2915                 VERIFY(nvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
2916                     spa->spa_load_info) == 0);
2917         }
2918 
2919         if (locked) {
2920                 spa->spa_last_open_failed = 0;
2921                 spa->spa_last_ubsync_txg = 0;
2922                 spa->spa_load_txg = 0;
2923                 mutex_exit(&spa_namespace_lock);
2924         }
2925 
2926         *spapp = spa;
2927 
2928         return (0);
2929 }
2930 
2931 int
2932 spa_open_rewind(const char *name, spa_t **spapp, void *tag, nvlist_t *policy,
2933     nvlist_t **config)
2934 {
2935         return (spa_open_common(name, spapp, tag, policy, config));
2936 }
2937 
2938 int
2939 spa_open(const char *name, spa_t **spapp, void *tag)
2940 {
2941         return (spa_open_common(name, spapp, tag, NULL, NULL));
2942 }
2943 
2944 /*
2945  * Lookup the given spa_t, incrementing the inject count in the process,
2946  * preventing it from being exported or destroyed.
2947  */
2948 spa_t *
2949 spa_inject_addref(char *name)
2950 {
2951         spa_t *spa;
2952 
2953         mutex_enter(&spa_namespace_lock);
2954         if ((spa = spa_lookup(name)) == NULL) {
2955                 mutex_exit(&spa_namespace_lock);
2956                 return (NULL);
2957         }
2958         spa->spa_inject_ref++;
2959         mutex_exit(&spa_namespace_lock);
2960 
2961         return (spa);
2962 }
2963 
2964 void
2965 spa_inject_delref(spa_t *spa)
2966 {
2967         mutex_enter(&spa_namespace_lock);
2968         spa->spa_inject_ref--;
2969         mutex_exit(&spa_namespace_lock);
2970 }
2971 
2972 /*
2973  * Add spares device information to the nvlist.
2974  */
2975 static void
2976 spa_add_spares(spa_t *spa, nvlist_t *config)
2977 {
2978         nvlist_t **spares;
2979         uint_t i, nspares;
2980         nvlist_t *nvroot;
2981         uint64_t guid;
2982         vdev_stat_t *vs;
2983         uint_t vsc;
2984         uint64_t pool;
2985 
2986         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
2987 
2988         if (spa->spa_spares.sav_count == 0)
2989                 return;
2990 
2991         VERIFY(nvlist_lookup_nvlist(config,
2992             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
2993         VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
2994             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
2995         if (nspares != 0) {
2996                 VERIFY(nvlist_add_nvlist_array(nvroot,
2997                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
2998                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
2999                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
3000 
3001                 /*
3002                  * Go through and find any spares which have since been
3003                  * repurposed as an active spare.  If this is the case, update
3004                  * their status appropriately.
3005                  */
3006                 for (i = 0; i < nspares; i++) {
3007                         VERIFY(nvlist_lookup_uint64(spares[i],
3008                             ZPOOL_CONFIG_GUID, &guid) == 0);
3009                         if (spa_spare_exists(guid, &pool, NULL) &&
3010                             pool != 0ULL) {
3011                                 VERIFY(nvlist_lookup_uint64_array(
3012                                     spares[i], ZPOOL_CONFIG_VDEV_STATS,
3013                                     (uint64_t **)&vs, &vsc) == 0);
3014                                 vs->vs_state = VDEV_STATE_CANT_OPEN;
3015                                 vs->vs_aux = VDEV_AUX_SPARED;
3016                         }
3017                 }
3018         }
3019 }
3020 
3021 /*
3022  * Add l2cache device information to the nvlist, including vdev stats.
3023  */
3024 static void
3025 spa_add_l2cache(spa_t *spa, nvlist_t *config)
3026 {
3027         nvlist_t **l2cache;
3028         uint_t i, j, nl2cache;
3029         nvlist_t *nvroot;
3030         uint64_t guid;
3031         vdev_t *vd;
3032         vdev_stat_t *vs;
3033         uint_t vsc;
3034 
3035         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3036 
3037         if (spa->spa_l2cache.sav_count == 0)
3038                 return;
3039 
3040         VERIFY(nvlist_lookup_nvlist(config,
3041             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3042         VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
3043             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3044         if (nl2cache != 0) {
3045                 VERIFY(nvlist_add_nvlist_array(nvroot,
3046                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3047                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
3048                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3049 
3050                 /*
3051                  * Update level 2 cache device stats.
3052                  */
3053 
3054                 for (i = 0; i < nl2cache; i++) {
3055                         VERIFY(nvlist_lookup_uint64(l2cache[i],
3056                             ZPOOL_CONFIG_GUID, &guid) == 0);
3057 
3058                         vd = NULL;
3059                         for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
3060                                 if (guid ==
3061                                     spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
3062                                         vd = spa->spa_l2cache.sav_vdevs[j];
3063                                         break;
3064                                 }
3065                         }
3066                         ASSERT(vd != NULL);
3067 
3068                         VERIFY(nvlist_lookup_uint64_array(l2cache[i],
3069                             ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc)
3070                             == 0);
3071                         vdev_get_stats(vd, vs);
3072                 }
3073         }
3074 }
3075 
3076 static void
3077 spa_add_feature_stats(spa_t *spa, nvlist_t *config)
3078 {
3079         nvlist_t *features;
3080         zap_cursor_t zc;
3081         zap_attribute_t za;
3082 
3083         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3084         VERIFY(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3085 
3086         if (spa->spa_feat_for_read_obj != 0) {
3087                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3088                     spa->spa_feat_for_read_obj);
3089                     zap_cursor_retrieve(&zc, &za) == 0;
3090                     zap_cursor_advance(&zc)) {
3091                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3092                             za.za_num_integers == 1);
3093                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3094                             za.za_first_integer));
3095                 }
3096                 zap_cursor_fini(&zc);
3097         }
3098 
3099         if (spa->spa_feat_for_write_obj != 0) {
3100                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3101                     spa->spa_feat_for_write_obj);
3102                     zap_cursor_retrieve(&zc, &za) == 0;
3103                     zap_cursor_advance(&zc)) {
3104                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3105                             za.za_num_integers == 1);
3106                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3107                             za.za_first_integer));
3108                 }
3109                 zap_cursor_fini(&zc);
3110         }
3111 
3112         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
3113             features) == 0);
3114         nvlist_free(features);
3115 }
3116 
3117 int
3118 spa_get_stats(const char *name, nvlist_t **config,
3119     char *altroot, size_t buflen)
3120 {
3121         int error;
3122         spa_t *spa;
3123 
3124         *config = NULL;
3125         error = spa_open_common(name, &spa, FTAG, NULL, config);
3126 
3127         if (spa != NULL) {
3128                 /*
3129                  * This still leaves a window of inconsistency where the spares
3130                  * or l2cache devices could change and the config would be
3131                  * self-inconsistent.
3132                  */
3133                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3134 
3135                 if (*config != NULL) {
3136                         uint64_t loadtimes[2];
3137 
3138                         loadtimes[0] = spa->spa_loaded_ts.tv_sec;
3139                         loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
3140                         VERIFY(nvlist_add_uint64_array(*config,
3141                             ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2) == 0);
3142 
3143                         VERIFY(nvlist_add_uint64(*config,
3144                             ZPOOL_CONFIG_ERRCOUNT,
3145                             spa_get_errlog_size(spa)) == 0);
3146 
3147                         if (spa_suspended(spa))
3148                                 VERIFY(nvlist_add_uint64(*config,
3149                                     ZPOOL_CONFIG_SUSPENDED,
3150                                     spa->spa_failmode) == 0);
3151 
3152                         spa_add_spares(spa, *config);
3153                         spa_add_l2cache(spa, *config);
3154                         spa_add_feature_stats(spa, *config);
3155                 }
3156         }
3157 
3158         /*
3159          * We want to get the alternate root even for faulted pools, so we cheat
3160          * and call spa_lookup() directly.
3161          */
3162         if (altroot) {
3163                 if (spa == NULL) {
3164                         mutex_enter(&spa_namespace_lock);
3165                         spa = spa_lookup(name);
3166                         if (spa)
3167                                 spa_altroot(spa, altroot, buflen);
3168                         else
3169                                 altroot[0] = '\0';
3170                         spa = NULL;
3171                         mutex_exit(&spa_namespace_lock);
3172                 } else {
3173                         spa_altroot(spa, altroot, buflen);
3174                 }
3175         }
3176 
3177         if (spa != NULL) {
3178                 spa_config_exit(spa, SCL_CONFIG, FTAG);
3179                 spa_close(spa, FTAG);
3180         }
3181 
3182         return (error);
3183 }
3184 
3185 /*
3186  * Validate that the auxiliary device array is well formed.  We must have an
3187  * array of nvlists, each which describes a valid leaf vdev.  If this is an
3188  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
3189  * specified, as long as they are well-formed.
3190  */
3191 static int
3192 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
3193     spa_aux_vdev_t *sav, const char *config, uint64_t version,
3194     vdev_labeltype_t label)
3195 {
3196         nvlist_t **dev;
3197         uint_t i, ndev;
3198         vdev_t *vd;
3199         int error;
3200 
3201         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3202 
3203         /*
3204          * It's acceptable to have no devs specified.
3205          */
3206         if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
3207                 return (0);
3208 
3209         if (ndev == 0)
3210                 return (SET_ERROR(EINVAL));
3211 
3212         /*
3213          * Make sure the pool is formatted with a version that supports this
3214          * device type.
3215          */
3216         if (spa_version(spa) < version)
3217                 return (SET_ERROR(ENOTSUP));
3218 
3219         /*
3220          * Set the pending device list so we correctly handle device in-use
3221          * checking.
3222          */
3223         sav->sav_pending = dev;
3224         sav->sav_npending = ndev;
3225 
3226         for (i = 0; i < ndev; i++) {
3227                 if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
3228                     mode)) != 0)
3229                         goto out;
3230 
3231                 if (!vd->vdev_ops->vdev_op_leaf) {
3232                         vdev_free(vd);
3233                         error = SET_ERROR(EINVAL);
3234                         goto out;
3235                 }
3236 
3237                 /*
3238                  * The L2ARC currently only supports disk devices in
3239                  * kernel context.  For user-level testing, we allow it.
3240                  */
3241 #ifdef _KERNEL
3242                 if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
3243                     strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
3244                         error = SET_ERROR(ENOTBLK);
3245                         vdev_free(vd);
3246                         goto out;
3247                 }
3248 #endif
3249                 vd->vdev_top = vd;
3250 
3251                 if ((error = vdev_open(vd)) == 0 &&
3252                     (error = vdev_label_init(vd, crtxg, label)) == 0) {
3253                         VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
3254                             vd->vdev_guid) == 0);
3255                 }
3256 
3257                 vdev_free(vd);
3258 
3259                 if (error &&
3260                     (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
3261                         goto out;
3262                 else
3263                         error = 0;
3264         }
3265 
3266 out:
3267         sav->sav_pending = NULL;
3268         sav->sav_npending = 0;
3269         return (error);
3270 }
3271 
3272 static int
3273 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
3274 {
3275         int error;
3276 
3277         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3278 
3279         if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3280             &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
3281             VDEV_LABEL_SPARE)) != 0) {
3282                 return (error);
3283         }
3284 
3285         return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3286             &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
3287             VDEV_LABEL_L2CACHE));
3288 }
3289 
3290 static void
3291 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
3292     const char *config)
3293 {
3294         int i;
3295 
3296         if (sav->sav_config != NULL) {
3297                 nvlist_t **olddevs;
3298                 uint_t oldndevs;
3299                 nvlist_t **newdevs;
3300 
3301                 /*
3302                  * Generate new dev list by concatentating with the
3303                  * current dev list.
3304                  */
3305                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
3306                     &olddevs, &oldndevs) == 0);
3307 
3308                 newdevs = kmem_alloc(sizeof (void *) *
3309                     (ndevs + oldndevs), KM_SLEEP);
3310                 for (i = 0; i < oldndevs; i++)
3311                         VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
3312                             KM_SLEEP) == 0);
3313                 for (i = 0; i < ndevs; i++)
3314                         VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
3315                             KM_SLEEP) == 0);
3316 
3317                 VERIFY(nvlist_remove(sav->sav_config, config,
3318                     DATA_TYPE_NVLIST_ARRAY) == 0);
3319 
3320                 VERIFY(nvlist_add_nvlist_array(sav->sav_config,
3321                     config, newdevs, ndevs + oldndevs) == 0);
3322                 for (i = 0; i < oldndevs + ndevs; i++)
3323                         nvlist_free(newdevs[i]);
3324                 kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
3325         } else {
3326                 /*
3327                  * Generate a new dev list.
3328                  */
3329                 VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
3330                     KM_SLEEP) == 0);
3331                 VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
3332                     devs, ndevs) == 0);
3333         }
3334 }
3335 
3336 /*
3337  * Stop and drop level 2 ARC devices
3338  */
3339 void
3340 spa_l2cache_drop(spa_t *spa)
3341 {
3342         vdev_t *vd;
3343         int i;
3344         spa_aux_vdev_t *sav = &spa->spa_l2cache;
3345 
3346         for (i = 0; i < sav->sav_count; i++) {
3347                 uint64_t pool;
3348 
3349                 vd = sav->sav_vdevs[i];
3350                 ASSERT(vd != NULL);
3351 
3352                 if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
3353                     pool != 0ULL && l2arc_vdev_present(vd))
3354                         l2arc_remove_vdev(vd);
3355         }
3356 }
3357 
3358 /*
3359  * Pool Creation
3360  */
3361 int
3362 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
3363     nvlist_t *zplprops)
3364 {
3365         spa_t *spa;
3366         char *altroot = NULL;
3367         vdev_t *rvd;
3368         dsl_pool_t *dp;
3369         dmu_tx_t *tx;
3370         int error = 0;
3371         uint64_t txg = TXG_INITIAL;
3372         nvlist_t **spares, **l2cache;
3373         uint_t nspares, nl2cache;
3374         uint64_t version, obj;
3375         boolean_t has_features;
3376 
3377         /*
3378          * If this pool already exists, return failure.
3379          */
3380         mutex_enter(&spa_namespace_lock);
3381         if (spa_lookup(pool) != NULL) {
3382                 mutex_exit(&spa_namespace_lock);
3383                 return (SET_ERROR(EEXIST));
3384         }
3385 
3386         /*
3387          * Allocate a new spa_t structure.
3388          */
3389         (void) nvlist_lookup_string(props,
3390             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3391         spa = spa_add(pool, NULL, altroot);
3392         spa_activate(spa, spa_mode_global);
3393 
3394         if (props && (error = spa_prop_validate(spa, props))) {
3395                 spa_deactivate(spa);
3396                 spa_remove(spa);
3397                 mutex_exit(&spa_namespace_lock);
3398                 return (error);
3399         }
3400 
3401         has_features = B_FALSE;
3402         for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
3403             elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
3404                 if (zpool_prop_feature(nvpair_name(elem)))
3405                         has_features = B_TRUE;
3406         }
3407 
3408         if (has_features || nvlist_lookup_uint64(props,
3409             zpool_prop_to_name(ZPOOL_PROP_VERSION), &version) != 0) {
3410                 version = SPA_VERSION;
3411         }
3412         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
3413 
3414         spa->spa_first_txg = txg;
3415         spa->spa_uberblock.ub_txg = txg - 1;
3416         spa->spa_uberblock.ub_version = version;
3417         spa->spa_ubsync = spa->spa_uberblock;
3418 
3419         /*
3420          * Create "The Godfather" zio to hold all async IOs
3421          */
3422         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
3423             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
3424 
3425         /*
3426          * Create the root vdev.
3427          */
3428         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3429 
3430         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
3431 
3432         ASSERT(error != 0 || rvd != NULL);
3433         ASSERT(error != 0 || spa->spa_root_vdev == rvd);
3434 
3435         if (error == 0 && !zfs_allocatable_devs(nvroot))
3436                 error = SET_ERROR(EINVAL);
3437 
3438         if (error == 0 &&
3439             (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
3440             (error = spa_validate_aux(spa, nvroot, txg,
3441             VDEV_ALLOC_ADD)) == 0) {
3442                 for (int c = 0; c < rvd->vdev_children; c++) {
3443                         vdev_metaslab_set_size(rvd->vdev_child[c]);
3444                         vdev_expand(rvd->vdev_child[c], txg);
3445                 }
3446         }
3447 
3448         spa_config_exit(spa, SCL_ALL, FTAG);
3449 
3450         if (error != 0) {
3451                 spa_unload(spa);
3452                 spa_deactivate(spa);
3453                 spa_remove(spa);
3454                 mutex_exit(&spa_namespace_lock);
3455                 return (error);
3456         }
3457 
3458         /*
3459          * Get the list of spares, if specified.
3460          */
3461         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3462             &spares, &nspares) == 0) {
3463                 VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
3464                     KM_SLEEP) == 0);
3465                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3466                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3467                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3468                 spa_load_spares(spa);
3469                 spa_config_exit(spa, SCL_ALL, FTAG);
3470                 spa->spa_spares.sav_sync = B_TRUE;
3471         }
3472 
3473         /*
3474          * Get the list of level 2 cache devices, if specified.
3475          */
3476         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3477             &l2cache, &nl2cache) == 0) {
3478                 VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3479                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
3480                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3481                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3482                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3483                 spa_load_l2cache(spa);
3484                 spa_config_exit(spa, SCL_ALL, FTAG);
3485                 spa->spa_l2cache.sav_sync = B_TRUE;
3486         }
3487 
3488         spa->spa_is_initializing = B_TRUE;
3489         spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
3490         spa->spa_meta_objset = dp->dp_meta_objset;
3491         spa->spa_is_initializing = B_FALSE;
3492 
3493         /*
3494          * Create DDTs (dedup tables).
3495          */
3496         ddt_create(spa);
3497 
3498         spa_update_dspace(spa);
3499 
3500         tx = dmu_tx_create_assigned(dp, txg);
3501 
3502         /*
3503          * Create the pool config object.
3504          */
3505         spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
3506             DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
3507             DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
3508 
3509         if (zap_add(spa->spa_meta_objset,
3510             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
3511             sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
3512                 cmn_err(CE_PANIC, "failed to add pool config");
3513         }
3514 
3515         if (spa_version(spa) >= SPA_VERSION_FEATURES)
3516                 spa_feature_create_zap_objects(spa, tx);
3517 
3518         if (zap_add(spa->spa_meta_objset,
3519             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
3520             sizeof (uint64_t), 1, &version, tx) != 0) {
3521                 cmn_err(CE_PANIC, "failed to add pool version");
3522         }
3523 
3524         /* Newly created pools with the right version are always deflated. */
3525         if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
3526                 spa->spa_deflate = TRUE;
3527                 if (zap_add(spa->spa_meta_objset,
3528                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
3529                     sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
3530                         cmn_err(CE_PANIC, "failed to add deflate");
3531                 }
3532         }
3533 
3534         /*
3535          * Create the deferred-free bpobj.  Turn off compression
3536          * because sync-to-convergence takes longer if the blocksize
3537          * keeps changing.
3538          */
3539         obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
3540         dmu_object_set_compress(spa->spa_meta_objset, obj,
3541             ZIO_COMPRESS_OFF, tx);
3542         if (zap_add(spa->spa_meta_objset,
3543             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
3544             sizeof (uint64_t), 1, &obj, tx) != 0) {
3545                 cmn_err(CE_PANIC, "failed to add bpobj");
3546         }
3547         VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
3548             spa->spa_meta_objset, obj));
3549 
3550         /*
3551          * Create the pool's history object.
3552          */
3553         if (version >= SPA_VERSION_ZPOOL_HISTORY)
3554                 spa_history_create_obj(spa, tx);
3555 
3556         /*
3557          * Set pool properties.
3558          */
3559         spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
3560         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
3561         spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
3562         spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
3563 
3564         if (props != NULL) {
3565                 spa_configfile_set(spa, props, B_FALSE);
3566                 spa_sync_props(props, tx);
3567         }
3568 
3569         dmu_tx_commit(tx);
3570 
3571         spa->spa_sync_on = B_TRUE;
3572         txg_sync_start(spa->spa_dsl_pool);
3573 
3574         /*
3575          * We explicitly wait for the first transaction to complete so that our
3576          * bean counters are appropriately updated.
3577          */
3578         txg_wait_synced(spa->spa_dsl_pool, txg);
3579 
3580         spa_config_sync(spa, B_FALSE, B_TRUE);
3581 
3582         spa_history_log_version(spa, "create");
3583 
3584         spa->spa_minref = refcount_count(&spa->spa_refcount);
3585 
3586         mutex_exit(&spa_namespace_lock);
3587 
3588         return (0);
3589 }
3590 
3591 #ifdef _KERNEL
3592 /*
3593  * Get the root pool information from the root disk, then import the root pool
3594  * during the system boot up time.
3595  */
3596 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
3597 
3598 static nvlist_t *
3599 spa_generate_rootconf(char *devpath, char *devid, uint64_t *guid)
3600 {
3601         nvlist_t *config;
3602         nvlist_t *nvtop, *nvroot;
3603         uint64_t pgid;
3604 
3605         if (vdev_disk_read_rootlabel(devpath, devid, &config) != 0)
3606                 return (NULL);
3607 
3608         /*
3609          * Add this top-level vdev to the child array.
3610          */
3611         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3612             &nvtop) == 0);
3613         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
3614             &pgid) == 0);
3615         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, guid) == 0);
3616 
3617         /*
3618          * Put this pool's top-level vdevs into a root vdev.
3619          */
3620         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3621         VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
3622             VDEV_TYPE_ROOT) == 0);
3623         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
3624         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
3625         VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
3626             &nvtop, 1) == 0);
3627 
3628         /*
3629          * Replace the existing vdev_tree with the new root vdev in
3630          * this pool's configuration (remove the old, add the new).
3631          */
3632         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
3633         nvlist_free(nvroot);
3634         return (config);
3635 }
3636 
3637 /*
3638  * Walk the vdev tree and see if we can find a device with "better"
3639  * configuration. A configuration is "better" if the label on that
3640  * device has a more recent txg.
3641  */
3642 static void
3643 spa_alt_rootvdev(vdev_t *vd, vdev_t **avd, uint64_t *txg)
3644 {
3645         for (int c = 0; c < vd->vdev_children; c++)
3646                 spa_alt_rootvdev(vd->vdev_child[c], avd, txg);
3647 
3648         if (vd->vdev_ops->vdev_op_leaf) {
3649                 nvlist_t *label;
3650                 uint64_t label_txg;
3651 
3652                 if (vdev_disk_read_rootlabel(vd->vdev_physpath, vd->vdev_devid,
3653                     &label) != 0)
3654                         return;
3655 
3656                 VERIFY(nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
3657                     &label_txg) == 0);
3658 
3659                 /*
3660                  * Do we have a better boot device?
3661                  */
3662                 if (label_txg > *txg) {
3663                         *txg = label_txg;
3664                         *avd = vd;
3665                 }
3666                 nvlist_free(label);
3667         }
3668 }
3669 
3670 /*
3671  * Import a root pool.
3672  *
3673  * For x86. devpath_list will consist of devid and/or physpath name of
3674  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
3675  * The GRUB "findroot" command will return the vdev we should boot.
3676  *
3677  * For Sparc, devpath_list consists the physpath name of the booting device
3678  * no matter the rootpool is a single device pool or a mirrored pool.
3679  * e.g.
3680  *      "/pci@1f,0/ide@d/disk@0,0:a"
3681  */
3682 int
3683 spa_import_rootpool(char *devpath, char *devid)
3684 {
3685         spa_t *spa;
3686         vdev_t *rvd, *bvd, *avd = NULL;
3687         nvlist_t *config, *nvtop;
3688         uint64_t guid, txg;
3689         char *pname;
3690         int error;
3691 
3692         /*
3693          * Read the label from the boot device and generate a configuration.
3694          */
3695         config = spa_generate_rootconf(devpath, devid, &guid);
3696 #if defined(_OBP) && defined(_KERNEL)
3697         if (config == NULL) {
3698                 if (strstr(devpath, "/iscsi/ssd") != NULL) {
3699                         /* iscsi boot */
3700                         get_iscsi_bootpath_phy(devpath);
3701                         config = spa_generate_rootconf(devpath, devid, &guid);
3702                 }
3703         }
3704 #endif
3705         if (config == NULL) {
3706                 cmn_err(CE_NOTE, "Cannot read the pool label from '%s'",
3707                     devpath);
3708                 return (SET_ERROR(EIO));
3709         }
3710 
3711         VERIFY(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
3712             &pname) == 0);
3713         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
3714 
3715         mutex_enter(&spa_namespace_lock);
3716         if ((spa = spa_lookup(pname)) != NULL) {
3717                 /*
3718                  * Remove the existing root pool from the namespace so that we
3719                  * can replace it with the correct config we just read in.
3720                  */
3721                 spa_remove(spa);
3722         }
3723 
3724         spa = spa_add(pname, config, NULL);
3725         spa->spa_is_root = B_TRUE;
3726         spa->spa_import_flags = ZFS_IMPORT_VERBATIM;
3727 
3728         /*
3729          * Build up a vdev tree based on the boot device's label config.
3730          */
3731         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3732             &nvtop) == 0);
3733         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3734         error = spa_config_parse(spa, &rvd, nvtop, NULL, 0,
3735             VDEV_ALLOC_ROOTPOOL);
3736         spa_config_exit(spa, SCL_ALL, FTAG);
3737         if (error) {
3738                 mutex_exit(&spa_namespace_lock);
3739                 nvlist_free(config);
3740                 cmn_err(CE_NOTE, "Can not parse the config for pool '%s'",
3741                     pname);
3742                 return (error);
3743         }
3744 
3745         /*
3746          * Get the boot vdev.
3747          */
3748         if ((bvd = vdev_lookup_by_guid(rvd, guid)) == NULL) {
3749                 cmn_err(CE_NOTE, "Can not find the boot vdev for guid %llu",
3750                     (u_longlong_t)guid);
3751                 error = SET_ERROR(ENOENT);
3752                 goto out;
3753         }
3754 
3755         /*
3756          * Determine if there is a better boot device.
3757          */
3758         avd = bvd;
3759         spa_alt_rootvdev(rvd, &avd, &txg);
3760         if (avd != bvd) {
3761                 cmn_err(CE_NOTE, "The boot device is 'degraded'. Please "
3762                     "try booting from '%s'", avd->vdev_path);
3763                 error = SET_ERROR(EINVAL);
3764                 goto out;
3765         }
3766 
3767         /*
3768          * If the boot device is part of a spare vdev then ensure that
3769          * we're booting off the active spare.
3770          */
3771         if (bvd->vdev_parent->vdev_ops == &vdev_spare_ops &&
3772             !bvd->vdev_isspare) {
3773                 cmn_err(CE_NOTE, "The boot device is currently spared. Please "
3774                     "try booting from '%s'",
3775                     bvd->vdev_parent->
3776                     vdev_child[bvd->vdev_parent->vdev_children - 1]->vdev_path);
3777                 error = SET_ERROR(EINVAL);
3778                 goto out;
3779         }
3780 
3781         error = 0;
3782 out:
3783         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3784         vdev_free(rvd);
3785         spa_config_exit(spa, SCL_ALL, FTAG);
3786         mutex_exit(&spa_namespace_lock);
3787 
3788         nvlist_free(config);
3789         return (error);
3790 }
3791 
3792 #endif
3793 
3794 /*
3795  * Import a non-root pool into the system.
3796  */
3797 int
3798 spa_import(const char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
3799 {
3800         spa_t *spa;
3801         char *altroot = NULL;
3802         spa_load_state_t state = SPA_LOAD_IMPORT;
3803         zpool_rewind_policy_t policy;
3804         uint64_t mode = spa_mode_global;
3805         uint64_t readonly = B_FALSE;
3806         int error;
3807         nvlist_t *nvroot;
3808         nvlist_t **spares, **l2cache;
3809         uint_t nspares, nl2cache;
3810 
3811         /*
3812          * If a pool with this name exists, return failure.
3813          */
3814         mutex_enter(&spa_namespace_lock);
3815         if (spa_lookup(pool) != NULL) {
3816                 mutex_exit(&spa_namespace_lock);
3817                 return (SET_ERROR(EEXIST));
3818         }
3819 
3820         /*
3821          * Create and initialize the spa structure.
3822          */
3823         (void) nvlist_lookup_string(props,
3824             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3825         (void) nvlist_lookup_uint64(props,
3826             zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
3827         if (readonly)
3828                 mode = FREAD;
3829         spa = spa_add(pool, config, altroot);
3830         spa->spa_import_flags = flags;
3831 
3832         /*
3833          * Verbatim import - Take a pool and insert it into the namespace
3834          * as if it had been loaded at boot.
3835          */
3836         if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
3837                 if (props != NULL)
3838                         spa_configfile_set(spa, props, B_FALSE);
3839 
3840                 spa_config_sync(spa, B_FALSE, B_TRUE);
3841 
3842                 mutex_exit(&spa_namespace_lock);
3843                 return (0);
3844         }
3845 
3846         spa_activate(spa, mode);
3847 
3848         /*
3849          * Don't start async tasks until we know everything is healthy.
3850          */
3851         spa_async_suspend(spa);
3852 
3853         zpool_get_rewind_policy(config, &policy);
3854         if (policy.zrp_request & ZPOOL_DO_REWIND)
3855                 state = SPA_LOAD_RECOVER;
3856 
3857         /*
3858          * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
3859          * because the user-supplied config is actually the one to trust when
3860          * doing an import.
3861          */
3862         if (state != SPA_LOAD_RECOVER)
3863                 spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
3864 
3865         error = spa_load_best(spa, state, B_TRUE, policy.zrp_txg,
3866             policy.zrp_request);
3867 
3868         /*
3869          * Propagate anything learned while loading the pool and pass it
3870          * back to caller (i.e. rewind info, missing devices, etc).
3871          */
3872         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
3873             spa->spa_load_info) == 0);
3874 
3875         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3876         /*
3877          * Toss any existing sparelist, as it doesn't have any validity
3878          * anymore, and conflicts with spa_has_spare().
3879          */
3880         if (spa->spa_spares.sav_config) {
3881                 nvlist_free(spa->spa_spares.sav_config);
3882                 spa->spa_spares.sav_config = NULL;
3883                 spa_load_spares(spa);
3884         }
3885         if (spa->spa_l2cache.sav_config) {
3886                 nvlist_free(spa->spa_l2cache.sav_config);
3887                 spa->spa_l2cache.sav_config = NULL;
3888                 spa_load_l2cache(spa);
3889         }
3890 
3891         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3892             &nvroot) == 0);
3893         if (error == 0)
3894                 error = spa_validate_aux(spa, nvroot, -1ULL,
3895                     VDEV_ALLOC_SPARE);
3896         if (error == 0)
3897                 error = spa_validate_aux(spa, nvroot, -1ULL,
3898                     VDEV_ALLOC_L2CACHE);
3899         spa_config_exit(spa, SCL_ALL, FTAG);
3900 
3901         if (props != NULL)
3902                 spa_configfile_set(spa, props, B_FALSE);
3903 
3904         if (error != 0 || (props && spa_writeable(spa) &&
3905             (error = spa_prop_set(spa, props)))) {
3906                 spa_unload(spa);
3907                 spa_deactivate(spa);
3908                 spa_remove(spa);
3909                 mutex_exit(&spa_namespace_lock);
3910                 return (error);
3911         }
3912 
3913         spa_async_resume(spa);
3914 
3915         /*
3916          * Override any spares and level 2 cache devices as specified by
3917          * the user, as these may have correct device names/devids, etc.
3918          */
3919         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3920             &spares, &nspares) == 0) {
3921                 if (spa->spa_spares.sav_config)
3922                         VERIFY(nvlist_remove(spa->spa_spares.sav_config,
3923                             ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
3924                 else
3925                         VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
3926                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
3927                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3928                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3929                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3930                 spa_load_spares(spa);
3931                 spa_config_exit(spa, SCL_ALL, FTAG);
3932                 spa->spa_spares.sav_sync = B_TRUE;
3933         }
3934         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3935             &l2cache, &nl2cache) == 0) {
3936                 if (spa->spa_l2cache.sav_config)
3937                         VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
3938                             ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
3939                 else
3940                         VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3941                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
3942                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3943                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3944                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3945                 spa_load_l2cache(spa);
3946                 spa_config_exit(spa, SCL_ALL, FTAG);
3947                 spa->spa_l2cache.sav_sync = B_TRUE;
3948         }
3949 
3950         /*
3951          * Check for any removed devices.
3952          */
3953         if (spa->spa_autoreplace) {
3954                 spa_aux_check_removed(&spa->spa_spares);
3955                 spa_aux_check_removed(&spa->spa_l2cache);
3956         }
3957 
3958         if (spa_writeable(spa)) {
3959                 /*
3960                  * Update the config cache to include the newly-imported pool.
3961                  */
3962                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
3963         }
3964 
3965         /*
3966          * It's possible that the pool was expanded while it was exported.
3967          * We kick off an async task to handle this for us.
3968          */
3969         spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
3970 
3971         mutex_exit(&spa_namespace_lock);
3972         spa_history_log_version(spa, "import");
3973 
3974         return (0);
3975 }
3976 
3977 nvlist_t *
3978 spa_tryimport(nvlist_t *tryconfig)
3979 {
3980         nvlist_t *config = NULL;
3981         char *poolname;
3982         spa_t *spa;
3983         uint64_t state;
3984         int error;
3985 
3986         if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
3987                 return (NULL);
3988 
3989         if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
3990                 return (NULL);
3991 
3992         /*
3993          * Create and initialize the spa structure.
3994          */
3995         mutex_enter(&spa_namespace_lock);
3996         spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
3997         spa_activate(spa, FREAD);
3998 
3999         /*
4000          * Pass off the heavy lifting to spa_load().
4001          * Pass TRUE for mosconfig because the user-supplied config
4002          * is actually the one to trust when doing an import.
4003          */
4004         error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING, B_TRUE);
4005 
4006         /*
4007          * If 'tryconfig' was at least parsable, return the current config.
4008          */
4009         if (spa->spa_root_vdev != NULL) {
4010                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
4011                 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
4012                     poolname) == 0);
4013                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4014                     state) == 0);
4015                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
4016                     spa->spa_uberblock.ub_timestamp) == 0);
4017                 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
4018                     spa->spa_load_info) == 0);
4019 
4020                 /*
4021                  * If the bootfs property exists on this pool then we
4022                  * copy it out so that external consumers can tell which
4023                  * pools are bootable.
4024                  */
4025                 if ((!error || error == EEXIST) && spa->spa_bootfs) {
4026                         char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4027 
4028                         /*
4029                          * We have to play games with the name since the
4030                          * pool was opened as TRYIMPORT_NAME.
4031                          */
4032                         if (dsl_dsobj_to_dsname(spa_name(spa),
4033                             spa->spa_bootfs, tmpname) == 0) {
4034                                 char *cp;
4035                                 char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4036 
4037                                 cp = strchr(tmpname, '/');
4038                                 if (cp == NULL) {
4039                                         (void) strlcpy(dsname, tmpname,
4040                                             MAXPATHLEN);
4041                                 } else {
4042                                         (void) snprintf(dsname, MAXPATHLEN,
4043                                             "%s/%s", poolname, ++cp);
4044                                 }
4045                                 VERIFY(nvlist_add_string(config,
4046                                     ZPOOL_CONFIG_BOOTFS, dsname) == 0);
4047                                 kmem_free(dsname, MAXPATHLEN);
4048                         }
4049                         kmem_free(tmpname, MAXPATHLEN);
4050                 }
4051 
4052                 /*
4053                  * Add the list of hot spares and level 2 cache devices.
4054                  */
4055                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
4056                 spa_add_spares(spa, config);
4057                 spa_add_l2cache(spa, config);
4058                 spa_config_exit(spa, SCL_CONFIG, FTAG);
4059         }
4060 
4061         spa_unload(spa);
4062         spa_deactivate(spa);
4063         spa_remove(spa);
4064         mutex_exit(&spa_namespace_lock);
4065 
4066         return (config);
4067 }
4068 
4069 /*
4070  * Pool export/destroy
4071  *
4072  * The act of destroying or exporting a pool is very simple.  We make sure there
4073  * is no more pending I/O and any references to the pool are gone.  Then, we
4074  * update the pool state and sync all the labels to disk, removing the
4075  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
4076  * we don't sync the labels or remove the configuration cache.
4077  */
4078 static int
4079 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
4080     boolean_t force, boolean_t hardforce)
4081 {
4082         spa_t *spa;
4083 
4084         if (oldconfig)
4085                 *oldconfig = NULL;
4086 
4087         if (!(spa_mode_global & FWRITE))
4088                 return (SET_ERROR(EROFS));
4089 
4090         mutex_enter(&spa_namespace_lock);
4091         if ((spa = spa_lookup(pool)) == NULL) {
4092                 mutex_exit(&spa_namespace_lock);
4093                 return (SET_ERROR(ENOENT));
4094         }
4095 
4096         /*
4097          * Put a hold on the pool, drop the namespace lock, stop async tasks,
4098          * reacquire the namespace lock, and see if we can export.
4099          */
4100         spa_open_ref(spa, FTAG);
4101         mutex_exit(&spa_namespace_lock);
4102         spa_async_suspend(spa);
4103         mutex_enter(&spa_namespace_lock);
4104         spa_close(spa, FTAG);
4105 
4106         /*
4107          * The pool will be in core if it's openable,
4108          * in which case we can modify its state.
4109          */
4110         if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
4111                 /*
4112                  * Objsets may be open only because they're dirty, so we
4113                  * have to force it to sync before checking spa_refcnt.
4114                  */
4115                 txg_wait_synced(spa->spa_dsl_pool, 0);
4116 
4117                 /*
4118                  * A pool cannot be exported or destroyed if there are active
4119                  * references.  If we are resetting a pool, allow references by
4120                  * fault injection handlers.
4121                  */
4122                 if (!spa_refcount_zero(spa) ||
4123                     (spa->spa_inject_ref != 0 &&
4124                     new_state != POOL_STATE_UNINITIALIZED)) {
4125                         spa_async_resume(spa);
4126                         mutex_exit(&spa_namespace_lock);
4127                         return (SET_ERROR(EBUSY));
4128                 }
4129 
4130                 /*
4131                  * A pool cannot be exported if it has an active shared spare.
4132                  * This is to prevent other pools stealing the active spare
4133                  * from an exported pool. At user's own will, such pool can
4134                  * be forcedly exported.
4135                  */
4136                 if (!force && new_state == POOL_STATE_EXPORTED &&
4137                     spa_has_active_shared_spare(spa)) {
4138                         spa_async_resume(spa);
4139                         mutex_exit(&spa_namespace_lock);
4140                         return (SET_ERROR(EXDEV));
4141                 }
4142 
4143                 /*
4144                  * We want this to be reflected on every label,
4145                  * so mark them all dirty.  spa_unload() will do the
4146                  * final sync that pushes these changes out.
4147                  */
4148                 if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
4149                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4150                         spa->spa_state = new_state;
4151                         spa->spa_final_txg = spa_last_synced_txg(spa) +
4152                             TXG_DEFER_SIZE + 1;
4153                         vdev_config_dirty(spa->spa_root_vdev);
4154                         spa_config_exit(spa, SCL_ALL, FTAG);
4155                 }
4156         }
4157 
4158         spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
4159 
4160         if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
4161                 spa_unload(spa);
4162                 spa_deactivate(spa);
4163         }
4164 
4165         if (oldconfig && spa->spa_config)
4166                 VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
4167 
4168         if (new_state != POOL_STATE_UNINITIALIZED) {
4169                 if (!hardforce)
4170                         spa_config_sync(spa, B_TRUE, B_TRUE);
4171                 spa_remove(spa);
4172         }
4173         mutex_exit(&spa_namespace_lock);
4174 
4175         return (0);
4176 }
4177 
4178 /*
4179  * Destroy a storage pool.
4180  */
4181 int
4182 spa_destroy(char *pool)
4183 {
4184         return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
4185             B_FALSE, B_FALSE));
4186 }
4187 
4188 /*
4189  * Export a storage pool.
4190  */
4191 int
4192 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
4193     boolean_t hardforce)
4194 {
4195         return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
4196             force, hardforce));
4197 }
4198 
4199 /*
4200  * Similar to spa_export(), this unloads the spa_t without actually removing it
4201  * from the namespace in any way.
4202  */
4203 int
4204 spa_reset(char *pool)
4205 {
4206         return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
4207             B_FALSE, B_FALSE));
4208 }
4209 
4210 /*
4211  * ==========================================================================
4212  * Device manipulation
4213  * ==========================================================================
4214  */
4215 
4216 /*
4217  * Add a device to a storage pool.
4218  */
4219 int
4220 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
4221 {
4222         uint64_t txg, id;
4223         int error;
4224         vdev_t *rvd = spa->spa_root_vdev;
4225         vdev_t *vd, *tvd;
4226         nvlist_t **spares, **l2cache;
4227         uint_t nspares, nl2cache;
4228 
4229         ASSERT(spa_writeable(spa));
4230 
4231         txg = spa_vdev_enter(spa);
4232 
4233         if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
4234             VDEV_ALLOC_ADD)) != 0)
4235                 return (spa_vdev_exit(spa, NULL, txg, error));
4236 
4237         spa->spa_pending_vdev = vd;  /* spa_vdev_exit() will clear this */
4238 
4239         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
4240             &nspares) != 0)
4241                 nspares = 0;
4242 
4243         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
4244             &nl2cache) != 0)
4245                 nl2cache = 0;
4246 
4247         if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
4248                 return (spa_vdev_exit(spa, vd, txg, EINVAL));
4249 
4250         if (vd->vdev_children != 0 &&
4251             (error = vdev_create(vd, txg, B_FALSE)) != 0)
4252                 return (spa_vdev_exit(spa, vd, txg, error));
4253 
4254         /*
4255          * We must validate the spares and l2cache devices after checking the
4256          * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
4257          */
4258         if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
4259                 return (spa_vdev_exit(spa, vd, txg, error));
4260 
4261         /*
4262          * Transfer each new top-level vdev from vd to rvd.
4263          */
4264         for (int c = 0; c < vd->vdev_children; c++) {
4265 
4266                 /*
4267                  * Set the vdev id to the first hole, if one exists.
4268                  */
4269                 for (id = 0; id < rvd->vdev_children; id++) {
4270                         if (rvd->vdev_child[id]->vdev_ishole) {
4271                                 vdev_free(rvd->vdev_child[id]);
4272                                 break;
4273                         }
4274                 }
4275                 tvd = vd->vdev_child[c];
4276                 vdev_remove_child(vd, tvd);
4277                 tvd->vdev_id = id;
4278                 vdev_add_child(rvd, tvd);
4279                 vdev_config_dirty(tvd);
4280         }
4281 
4282         if (nspares != 0) {
4283                 spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
4284                     ZPOOL_CONFIG_SPARES);
4285                 spa_load_spares(spa);
4286                 spa->spa_spares.sav_sync = B_TRUE;
4287         }
4288 
4289         if (nl2cache != 0) {
4290                 spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
4291                     ZPOOL_CONFIG_L2CACHE);
4292                 spa_load_l2cache(spa);
4293                 spa->spa_l2cache.sav_sync = B_TRUE;
4294         }
4295 
4296         /*
4297          * We have to be careful when adding new vdevs to an existing pool.
4298          * If other threads start allocating from these vdevs before we
4299          * sync the config cache, and we lose power, then upon reboot we may
4300          * fail to open the pool because there are DVAs that the config cache
4301          * can't translate.  Therefore, we first add the vdevs without
4302          * initializing metaslabs; sync the config cache (via spa_vdev_exit());
4303          * and then let spa_config_update() initialize the new metaslabs.
4304          *
4305          * spa_load() checks for added-but-not-initialized vdevs, so that
4306          * if we lose power at any point in this sequence, the remaining
4307          * steps will be completed the next time we load the pool.
4308          */
4309         (void) spa_vdev_exit(spa, vd, txg, 0);
4310 
4311         mutex_enter(&spa_namespace_lock);
4312         spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4313         mutex_exit(&spa_namespace_lock);
4314 
4315         return (0);
4316 }
4317 
4318 /*
4319  * Attach a device to a mirror.  The arguments are the path to any device
4320  * in the mirror, and the nvroot for the new device.  If the path specifies
4321  * a device that is not mirrored, we automatically insert the mirror vdev.
4322  *
4323  * If 'replacing' is specified, the new device is intended to replace the
4324  * existing device; in this case the two devices are made into their own
4325  * mirror using the 'replacing' vdev, which is functionally identical to
4326  * the mirror vdev (it actually reuses all the same ops) but has a few
4327  * extra rules: you can't attach to it after it's been created, and upon
4328  * completion of resilvering, the first disk (the one being replaced)
4329  * is automatically detached.
4330  */
4331 int
4332 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
4333 {
4334         uint64_t txg, dtl_max_txg;
4335         vdev_t *rvd = spa->spa_root_vdev;
4336         vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
4337         vdev_ops_t *pvops;
4338         char *oldvdpath, *newvdpath;
4339         int newvd_isspare;
4340         int error;
4341 
4342         ASSERT(spa_writeable(spa));
4343 
4344         txg = spa_vdev_enter(spa);
4345 
4346         oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
4347 
4348         if (oldvd == NULL)
4349                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4350 
4351         if (!oldvd->vdev_ops->vdev_op_leaf)
4352                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4353 
4354         pvd = oldvd->vdev_parent;
4355 
4356         if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
4357             VDEV_ALLOC_ATTACH)) != 0)
4358                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4359 
4360         if (newrootvd->vdev_children != 1)
4361                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4362 
4363         newvd = newrootvd->vdev_child[0];
4364 
4365         if (!newvd->vdev_ops->vdev_op_leaf)
4366                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4367 
4368         if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
4369                 return (spa_vdev_exit(spa, newrootvd, txg, error));
4370 
4371         /*
4372          * Spares can't replace logs
4373          */
4374         if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
4375                 return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4376 
4377         if (!replacing) {
4378                 /*
4379                  * For attach, the only allowable parent is a mirror or the root
4380                  * vdev.
4381                  */
4382                 if (pvd->vdev_ops != &vdev_mirror_ops &&
4383                     pvd->vdev_ops != &vdev_root_ops)
4384                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4385 
4386                 pvops = &vdev_mirror_ops;
4387         } else {
4388                 /*
4389                  * Active hot spares can only be replaced by inactive hot
4390                  * spares.
4391                  */
4392                 if (pvd->vdev_ops == &vdev_spare_ops &&
4393                     oldvd->vdev_isspare &&
4394                     !spa_has_spare(spa, newvd->vdev_guid))
4395                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4396 
4397                 /*
4398                  * If the source is a hot spare, and the parent isn't already a
4399                  * spare, then we want to create a new hot spare.  Otherwise, we
4400                  * want to create a replacing vdev.  The user is not allowed to
4401                  * attach to a spared vdev child unless the 'isspare' state is
4402                  * the same (spare replaces spare, non-spare replaces
4403                  * non-spare).
4404                  */
4405                 if (pvd->vdev_ops == &vdev_replacing_ops &&
4406                     spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
4407                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4408                 } else if (pvd->vdev_ops == &vdev_spare_ops &&
4409                     newvd->vdev_isspare != oldvd->vdev_isspare) {
4410                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4411                 }
4412 
4413                 if (newvd->vdev_isspare)
4414                         pvops = &vdev_spare_ops;
4415                 else
4416                         pvops = &vdev_replacing_ops;
4417         }
4418 
4419         /*
4420          * Make sure the new device is big enough.
4421          */
4422         if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
4423                 return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
4424 
4425         /*
4426          * The new device cannot have a higher alignment requirement
4427          * than the top-level vdev.
4428          */
4429         if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
4430                 return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
4431 
4432         /*
4433          * If this is an in-place replacement, update oldvd's path and devid
4434          * to make it distinguishable from newvd, and unopenable from now on.
4435          */
4436         if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
4437                 spa_strfree(oldvd->vdev_path);
4438                 oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
4439                     KM_SLEEP);
4440                 (void) sprintf(oldvd->vdev_path, "%s/%s",
4441                     newvd->vdev_path, "old");
4442                 if (oldvd->vdev_devid != NULL) {
4443                         spa_strfree(oldvd->vdev_devid);
4444                         oldvd->vdev_devid = NULL;
4445                 }
4446         }
4447 
4448         /* mark the device being resilvered */
4449         newvd->vdev_resilver_txg = txg;
4450 
4451         /*
4452          * If the parent is not a mirror, or if we're replacing, insert the new
4453          * mirror/replacing/spare vdev above oldvd.
4454          */
4455         if (pvd->vdev_ops != pvops)
4456                 pvd = vdev_add_parent(oldvd, pvops);
4457 
4458         ASSERT(pvd->vdev_top->vdev_parent == rvd);
4459         ASSERT(pvd->vdev_ops == pvops);
4460         ASSERT(oldvd->vdev_parent == pvd);
4461 
4462         /*
4463          * Extract the new device from its root and add it to pvd.
4464          */
4465         vdev_remove_child(newrootvd, newvd);
4466         newvd->vdev_id = pvd->vdev_children;
4467         newvd->vdev_crtxg = oldvd->vdev_crtxg;
4468         vdev_add_child(pvd, newvd);
4469 
4470         tvd = newvd->vdev_top;
4471         ASSERT(pvd->vdev_top == tvd);
4472         ASSERT(tvd->vdev_parent == rvd);
4473 
4474         vdev_config_dirty(tvd);
4475 
4476         /*
4477          * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
4478          * for any dmu_sync-ed blocks.  It will propagate upward when
4479          * spa_vdev_exit() calls vdev_dtl_reassess().
4480          */
4481         dtl_max_txg = txg + TXG_CONCURRENT_STATES;
4482 
4483         vdev_dtl_dirty(newvd, DTL_MISSING, TXG_INITIAL,
4484             dtl_max_txg - TXG_INITIAL);
4485 
4486         if (newvd->vdev_isspare) {
4487                 spa_spare_activate(newvd);
4488                 spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
4489         }
4490 
4491         oldvdpath = spa_strdup(oldvd->vdev_path);
4492         newvdpath = spa_strdup(newvd->vdev_path);
4493         newvd_isspare = newvd->vdev_isspare;
4494 
4495         /*
4496          * Mark newvd's DTL dirty in this txg.
4497          */
4498         vdev_dirty(tvd, VDD_DTL, newvd, txg);
4499 
4500         /*
4501          * Schedule the resilver to restart in the future. We do this to
4502          * ensure that dmu_sync-ed blocks have been stitched into the
4503          * respective datasets.
4504          */
4505         dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
4506 
4507         /*
4508          * Commit the config
4509          */
4510         (void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
4511 
4512         spa_history_log_internal(spa, "vdev attach", NULL,
4513             "%s vdev=%s %s vdev=%s",
4514             replacing && newvd_isspare ? "spare in" :
4515             replacing ? "replace" : "attach", newvdpath,
4516             replacing ? "for" : "to", oldvdpath);
4517 
4518         spa_strfree(oldvdpath);
4519         spa_strfree(newvdpath);
4520 
4521         if (spa->spa_bootfs)
4522                 spa_event_notify(spa, newvd, ESC_ZFS_BOOTFS_VDEV_ATTACH);
4523 
4524         return (0);
4525 }
4526 
4527 /*
4528  * Detach a device from a mirror or replacing vdev.
4529  *
4530  * If 'replace_done' is specified, only detach if the parent
4531  * is a replacing vdev.
4532  */
4533 int
4534 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
4535 {
4536         uint64_t txg;
4537         int error;
4538         vdev_t *rvd = spa->spa_root_vdev;
4539         vdev_t *vd, *pvd, *cvd, *tvd;
4540         boolean_t unspare = B_FALSE;
4541         uint64_t unspare_guid = 0;
4542         char *vdpath;
4543 
4544         ASSERT(spa_writeable(spa));
4545 
4546         txg = spa_vdev_enter(spa);
4547 
4548         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4549 
4550         if (vd == NULL)
4551                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4552 
4553         if (!vd->vdev_ops->vdev_op_leaf)
4554                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4555 
4556         pvd = vd->vdev_parent;
4557 
4558         /*
4559          * If the parent/child relationship is not as expected, don't do it.
4560          * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
4561          * vdev that's replacing B with C.  The user's intent in replacing
4562          * is to go from M(A,B) to M(A,C).  If the user decides to cancel
4563          * the replace by detaching C, the expected behavior is to end up
4564          * M(A,B).  But suppose that right after deciding to detach C,
4565          * the replacement of B completes.  We would have M(A,C), and then
4566          * ask to detach C, which would leave us with just A -- not what
4567          * the user wanted.  To prevent this, we make sure that the
4568          * parent/child relationship hasn't changed -- in this example,
4569          * that C's parent is still the replacing vdev R.
4570          */
4571         if (pvd->vdev_guid != pguid && pguid != 0)
4572                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4573 
4574         /*
4575          * Only 'replacing' or 'spare' vdevs can be replaced.
4576          */
4577         if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
4578             pvd->vdev_ops != &vdev_spare_ops)
4579                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4580 
4581         ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
4582             spa_version(spa) >= SPA_VERSION_SPARES);
4583 
4584         /*
4585          * Only mirror, replacing, and spare vdevs support detach.
4586          */
4587         if (pvd->vdev_ops != &vdev_replacing_ops &&
4588             pvd->vdev_ops != &vdev_mirror_ops &&
4589             pvd->vdev_ops != &vdev_spare_ops)
4590                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4591 
4592         /*
4593          * If this device has the only valid copy of some data,
4594          * we cannot safely detach it.
4595          */
4596         if (vdev_dtl_required(vd))
4597                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4598 
4599         ASSERT(pvd->vdev_children >= 2);
4600 
4601         /*
4602          * If we are detaching the second disk from a replacing vdev, then
4603          * check to see if we changed the original vdev's path to have "/old"
4604          * at the end in spa_vdev_attach().  If so, undo that change now.
4605          */
4606         if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
4607             vd->vdev_path != NULL) {
4608                 size_t len = strlen(vd->vdev_path);
4609 
4610                 for (int c = 0; c < pvd->vdev_children; c++) {
4611                         cvd = pvd->vdev_child[c];
4612 
4613                         if (cvd == vd || cvd->vdev_path == NULL)
4614                                 continue;
4615 
4616                         if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
4617                             strcmp(cvd->vdev_path + len, "/old") == 0) {
4618                                 spa_strfree(cvd->vdev_path);
4619                                 cvd->vdev_path = spa_strdup(vd->vdev_path);
4620                                 break;
4621                         }
4622                 }
4623         }
4624 
4625         /*
4626          * If we are detaching the original disk from a spare, then it implies
4627          * that the spare should become a real disk, and be removed from the
4628          * active spare list for the pool.
4629          */
4630         if (pvd->vdev_ops == &vdev_spare_ops &&
4631             vd->vdev_id == 0 &&
4632             pvd->vdev_child[pvd->vdev_children - 1]->vdev_isspare)
4633                 unspare = B_TRUE;
4634 
4635         /*
4636          * Erase the disk labels so the disk can be used for other things.
4637          * This must be done after all other error cases are handled,
4638          * but before we disembowel vd (so we can still do I/O to it).
4639          * But if we can't do it, don't treat the error as fatal --
4640          * it may be that the unwritability of the disk is the reason
4641          * it's being detached!
4642          */
4643         error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4644 
4645         /*
4646          * Remove vd from its parent and compact the parent's children.
4647          */
4648         vdev_remove_child(pvd, vd);
4649         vdev_compact_children(pvd);
4650 
4651         /*
4652          * Remember one of the remaining children so we can get tvd below.
4653          */
4654         cvd = pvd->vdev_child[pvd->vdev_children - 1];
4655 
4656         /*
4657          * If we need to remove the remaining child from the list of hot spares,
4658          * do it now, marking the vdev as no longer a spare in the process.
4659          * We must do this before vdev_remove_parent(), because that can
4660          * change the GUID if it creates a new toplevel GUID.  For a similar
4661          * reason, we must remove the spare now, in the same txg as the detach;
4662          * otherwise someone could attach a new sibling, change the GUID, and
4663          * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
4664          */
4665         if (unspare) {
4666                 ASSERT(cvd->vdev_isspare);
4667                 spa_spare_remove(cvd);
4668                 unspare_guid = cvd->vdev_guid;
4669                 (void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
4670                 cvd->vdev_unspare = B_TRUE;
4671         }
4672 
4673         /*
4674          * If the parent mirror/replacing vdev only has one child,
4675          * the parent is no longer needed.  Remove it from the tree.
4676          */
4677         if (pvd->vdev_children == 1) {
4678                 if (pvd->vdev_ops == &vdev_spare_ops)
4679                         cvd->vdev_unspare = B_FALSE;
4680                 vdev_remove_parent(cvd);
4681         }
4682 
4683 
4684         /*
4685          * We don't set tvd until now because the parent we just removed
4686          * may have been the previous top-level vdev.
4687          */
4688         tvd = cvd->vdev_top;
4689         ASSERT(tvd->vdev_parent == rvd);
4690 
4691         /*
4692          * Reevaluate the parent vdev state.
4693          */
4694         vdev_propagate_state(cvd);
4695 
4696         /*
4697          * If the 'autoexpand' property is set on the pool then automatically
4698          * try to expand the size of the pool. For example if the device we
4699          * just detached was smaller than the others, it may be possible to
4700          * add metaslabs (i.e. grow the pool). We need to reopen the vdev
4701          * first so that we can obtain the updated sizes of the leaf vdevs.
4702          */
4703         if (spa->spa_autoexpand) {
4704                 vdev_reopen(tvd);
4705                 vdev_expand(tvd, txg);
4706         }
4707 
4708         vdev_config_dirty(tvd);
4709 
4710         /*
4711          * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
4712          * vd->vdev_detached is set and free vd's DTL object in syncing context.
4713          * But first make sure we're not on any *other* txg's DTL list, to
4714          * prevent vd from being accessed after it's freed.
4715          */
4716         vdpath = spa_strdup(vd->vdev_path);
4717         for (int t = 0; t < TXG_SIZE; t++)
4718                 (void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
4719         vd->vdev_detached = B_TRUE;
4720         vdev_dirty(tvd, VDD_DTL, vd, txg);
4721 
4722         spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
4723 
4724         /* hang on to the spa before we release the lock */
4725         spa_open_ref(spa, FTAG);
4726 
4727         error = spa_vdev_exit(spa, vd, txg, 0);
4728 
4729         spa_history_log_internal(spa, "detach", NULL,
4730             "vdev=%s", vdpath);
4731         spa_strfree(vdpath);
4732 
4733         /*
4734          * If this was the removal of the original device in a hot spare vdev,
4735          * then we want to go through and remove the device from the hot spare
4736          * list of every other pool.
4737          */
4738         if (unspare) {
4739                 spa_t *altspa = NULL;
4740 
4741                 mutex_enter(&spa_namespace_lock);
4742                 while ((altspa = spa_next(altspa)) != NULL) {
4743                         if (altspa->spa_state != POOL_STATE_ACTIVE ||
4744                             altspa == spa)
4745                                 continue;
4746 
4747                         spa_open_ref(altspa, FTAG);
4748                         mutex_exit(&spa_namespace_lock);
4749                         (void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
4750                         mutex_enter(&spa_namespace_lock);
4751                         spa_close(altspa, FTAG);
4752                 }
4753                 mutex_exit(&spa_namespace_lock);
4754 
4755                 /* search the rest of the vdevs for spares to remove */
4756                 spa_vdev_resilver_done(spa);
4757         }
4758 
4759         /* all done with the spa; OK to release */
4760         mutex_enter(&spa_namespace_lock);
4761         spa_close(spa, FTAG);
4762         mutex_exit(&spa_namespace_lock);
4763 
4764         return (error);
4765 }
4766 
4767 /*
4768  * Split a set of devices from their mirrors, and create a new pool from them.
4769  */
4770 int
4771 spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
4772     nvlist_t *props, boolean_t exp)
4773 {
4774         int error = 0;
4775         uint64_t txg, *glist;
4776         spa_t *newspa;
4777         uint_t c, children, lastlog;
4778         nvlist_t **child, *nvl, *tmp;
4779         dmu_tx_t *tx;
4780         char *altroot = NULL;
4781         vdev_t *rvd, **vml = NULL;                      /* vdev modify list */
4782         boolean_t activate_slog;
4783 
4784         ASSERT(spa_writeable(spa));
4785 
4786         txg = spa_vdev_enter(spa);
4787 
4788         /* clear the log and flush everything up to now */
4789         activate_slog = spa_passivate_log(spa);
4790         (void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4791         error = spa_offline_log(spa);
4792         txg = spa_vdev_config_enter(spa);
4793 
4794         if (activate_slog)
4795                 spa_activate_log(spa);
4796 
4797         if (error != 0)
4798                 return (spa_vdev_exit(spa, NULL, txg, error));
4799 
4800         /* check new spa name before going any further */
4801         if (spa_lookup(newname) != NULL)
4802                 return (spa_vdev_exit(spa, NULL, txg, EEXIST));
4803 
4804         /*
4805          * scan through all the children to ensure they're all mirrors
4806          */
4807         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
4808             nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
4809             &children) != 0)
4810                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4811 
4812         /* first, check to ensure we've got the right child count */
4813         rvd = spa->spa_root_vdev;
4814         lastlog = 0;
4815         for (c = 0; c < rvd->vdev_children; c++) {
4816                 vdev_t *vd = rvd->vdev_child[c];
4817 
4818                 /* don't count the holes & logs as children */
4819                 if (vd->vdev_islog || vd->vdev_ishole) {
4820                         if (lastlog == 0)
4821                                 lastlog = c;
4822                         continue;
4823                 }
4824 
4825                 lastlog = 0;
4826         }
4827         if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
4828                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4829 
4830         /* next, ensure no spare or cache devices are part of the split */
4831         if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
4832             nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
4833                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4834 
4835         vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
4836         glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
4837 
4838         /* then, loop over each vdev and validate it */
4839         for (c = 0; c < children; c++) {
4840                 uint64_t is_hole = 0;
4841 
4842                 (void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
4843                     &is_hole);
4844 
4845                 if (is_hole != 0) {
4846                         if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
4847                             spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
4848                                 continue;
4849                         } else {
4850                                 error = SET_ERROR(EINVAL);
4851                                 break;
4852                         }
4853                 }
4854 
4855                 /* which disk is going to be split? */
4856                 if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
4857                     &glist[c]) != 0) {
4858                         error = SET_ERROR(EINVAL);
4859                         break;
4860                 }
4861 
4862                 /* look it up in the spa */
4863                 vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
4864                 if (vml[c] == NULL) {
4865                         error = SET_ERROR(ENODEV);
4866                         break;
4867                 }
4868 
4869                 /* make sure there's nothing stopping the split */
4870                 if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
4871                     vml[c]->vdev_islog ||
4872                     vml[c]->vdev_ishole ||
4873                     vml[c]->vdev_isspare ||
4874                     vml[c]->vdev_isl2cache ||
4875                     !vdev_writeable(vml[c]) ||
4876                     vml[c]->vdev_children != 0 ||
4877                     vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
4878                     c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
4879                         error = SET_ERROR(EINVAL);
4880                         break;
4881                 }
4882 
4883                 if (vdev_dtl_required(vml[c])) {
4884                         error = SET_ERROR(EBUSY);
4885                         break;
4886                 }
4887 
4888                 /* we need certain info from the top level */
4889                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
4890                     vml[c]->vdev_top->vdev_ms_array) == 0);
4891                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
4892                     vml[c]->vdev_top->vdev_ms_shift) == 0);
4893                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
4894                     vml[c]->vdev_top->vdev_asize) == 0);
4895                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
4896                     vml[c]->vdev_top->vdev_ashift) == 0);
4897         }
4898 
4899         if (error != 0) {
4900                 kmem_free(vml, children * sizeof (vdev_t *));
4901                 kmem_free(glist, children * sizeof (uint64_t));
4902                 return (spa_vdev_exit(spa, NULL, txg, error));
4903         }
4904 
4905         /* stop writers from using the disks */
4906         for (c = 0; c < children; c++) {
4907                 if (vml[c] != NULL)
4908                         vml[c]->vdev_offline = B_TRUE;
4909         }
4910         vdev_reopen(spa->spa_root_vdev);
4911 
4912         /*
4913          * Temporarily record the splitting vdevs in the spa config.  This
4914          * will disappear once the config is regenerated.
4915          */
4916         VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0);
4917         VERIFY(nvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
4918             glist, children) == 0);
4919         kmem_free(glist, children * sizeof (uint64_t));
4920 
4921         mutex_enter(&spa->spa_props_lock);
4922         VERIFY(nvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT,
4923             nvl) == 0);
4924         mutex_exit(&spa->spa_props_lock);
4925         spa->spa_config_splitting = nvl;
4926         vdev_config_dirty(spa->spa_root_vdev);
4927 
4928         /* configure and create the new pool */
4929         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname) == 0);
4930         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4931             exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE) == 0);
4932         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
4933             spa_version(spa)) == 0);
4934         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
4935             spa->spa_config_txg) == 0);
4936         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
4937             spa_generate_guid(NULL)) == 0);
4938         (void) nvlist_lookup_string(props,
4939             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
4940 
4941         /* add the new pool to the namespace */
4942         newspa = spa_add(newname, config, altroot);
4943         newspa->spa_config_txg = spa->spa_config_txg;
4944         spa_set_log_state(newspa, SPA_LOG_CLEAR);
4945 
4946         /* release the spa config lock, retaining the namespace lock */
4947         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4948 
4949         if (zio_injection_enabled)
4950                 zio_handle_panic_injection(spa, FTAG, 1);
4951 
4952         spa_activate(newspa, spa_mode_global);
4953         spa_async_suspend(newspa);
4954 
4955         /* create the new pool from the disks of the original pool */
4956         error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE, B_TRUE);
4957         if (error)
4958                 goto out;
4959 
4960         /* if that worked, generate a real config for the new pool */
4961         if (newspa->spa_root_vdev != NULL) {
4962                 VERIFY(nvlist_alloc(&newspa->spa_config_splitting,
4963                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
4964                 VERIFY(nvlist_add_uint64(newspa->spa_config_splitting,
4965                     ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa)) == 0);
4966                 spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
4967                     B_TRUE));
4968         }
4969 
4970         /* set the props */
4971         if (props != NULL) {
4972                 spa_configfile_set(newspa, props, B_FALSE);
4973                 error = spa_prop_set(newspa, props);
4974                 if (error)
4975                         goto out;
4976         }
4977 
4978         /* flush everything */
4979         txg = spa_vdev_config_enter(newspa);
4980         vdev_config_dirty(newspa->spa_root_vdev);
4981         (void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
4982 
4983         if (zio_injection_enabled)
4984                 zio_handle_panic_injection(spa, FTAG, 2);
4985 
4986         spa_async_resume(newspa);
4987 
4988         /* finally, update the original pool's config */
4989         txg = spa_vdev_config_enter(spa);
4990         tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
4991         error = dmu_tx_assign(tx, TXG_WAIT);
4992         if (error != 0)
4993                 dmu_tx_abort(tx);
4994         for (c = 0; c < children; c++) {
4995                 if (vml[c] != NULL) {
4996                         vdev_split(vml[c]);
4997                         if (error == 0)
4998                                 spa_history_log_internal(spa, "detach", tx,
4999                                     "vdev=%s", vml[c]->vdev_path);
5000                         vdev_free(vml[c]);
5001                 }
5002         }
5003         vdev_config_dirty(spa->spa_root_vdev);
5004         spa->spa_config_splitting = NULL;
5005         nvlist_free(nvl);
5006         if (error == 0)
5007                 dmu_tx_commit(tx);
5008         (void) spa_vdev_exit(spa, NULL, txg, 0);
5009 
5010         if (zio_injection_enabled)
5011                 zio_handle_panic_injection(spa, FTAG, 3);
5012 
5013         /* split is complete; log a history record */
5014         spa_history_log_internal(newspa, "split", NULL,
5015             "from pool %s", spa_name(spa));
5016 
5017         kmem_free(vml, children * sizeof (vdev_t *));
5018 
5019         /* if we're not going to mount the filesystems in userland, export */
5020         if (exp)
5021                 error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
5022                     B_FALSE, B_FALSE);
5023 
5024         return (error);
5025 
5026 out:
5027         spa_unload(newspa);
5028         spa_deactivate(newspa);
5029         spa_remove(newspa);
5030 
5031         txg = spa_vdev_config_enter(spa);
5032 
5033         /* re-online all offlined disks */
5034         for (c = 0; c < children; c++) {
5035                 if (vml[c] != NULL)
5036                         vml[c]->vdev_offline = B_FALSE;
5037         }
5038         vdev_reopen(spa->spa_root_vdev);
5039 
5040         nvlist_free(spa->spa_config_splitting);
5041         spa->spa_config_splitting = NULL;
5042         (void) spa_vdev_exit(spa, NULL, txg, error);
5043 
5044         kmem_free(vml, children * sizeof (vdev_t *));
5045         return (error);
5046 }
5047 
5048 static nvlist_t *
5049 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
5050 {
5051         for (int i = 0; i < count; i++) {
5052                 uint64_t guid;
5053 
5054                 VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
5055                     &guid) == 0);
5056 
5057                 if (guid == target_guid)
5058                         return (nvpp[i]);
5059         }
5060 
5061         return (NULL);
5062 }
5063 
5064 static void
5065 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
5066         nvlist_t *dev_to_remove)
5067 {
5068         nvlist_t **newdev = NULL;
5069 
5070         if (count > 1)
5071                 newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
5072 
5073         for (int i = 0, j = 0; i < count; i++) {
5074                 if (dev[i] == dev_to_remove)
5075                         continue;
5076                 VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
5077         }
5078 
5079         VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
5080         VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
5081 
5082         for (int i = 0; i < count - 1; i++)
5083                 nvlist_free(newdev[i]);
5084 
5085         if (count > 1)
5086                 kmem_free(newdev, (count - 1) * sizeof (void *));
5087 }
5088 
5089 /*
5090  * Evacuate the device.
5091  */
5092 static int
5093 spa_vdev_remove_evacuate(spa_t *spa, vdev_t *vd)
5094 {
5095         uint64_t txg;
5096         int error = 0;
5097 
5098         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5099         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5100         ASSERT(vd == vd->vdev_top);
5101 
5102         /*
5103          * Evacuate the device.  We don't hold the config lock as writer
5104          * since we need to do I/O but we do keep the
5105          * spa_namespace_lock held.  Once this completes the device
5106          * should no longer have any blocks allocated on it.
5107          */
5108         if (vd->vdev_islog) {
5109                 if (vd->vdev_stat.vs_alloc != 0)
5110                         error = spa_offline_log(spa);
5111         } else {
5112                 error = SET_ERROR(ENOTSUP);
5113         }
5114 
5115         if (error)
5116                 return (error);
5117 
5118         /*
5119          * The evacuation succeeded.  Remove any remaining MOS metadata
5120          * associated with this vdev, and wait for these changes to sync.
5121          */
5122         ASSERT0(vd->vdev_stat.vs_alloc);
5123         txg = spa_vdev_config_enter(spa);
5124         vd->vdev_removing = B_TRUE;
5125         vdev_dirty_leaves(vd, VDD_DTL, txg);
5126         vdev_config_dirty(vd);
5127         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
5128 
5129         return (0);
5130 }
5131 
5132 /*
5133  * Complete the removal by cleaning up the namespace.
5134  */
5135 static void
5136 spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
5137 {
5138         vdev_t *rvd = spa->spa_root_vdev;
5139         uint64_t id = vd->vdev_id;
5140         boolean_t last_vdev = (id == (rvd->vdev_children - 1));
5141 
5142         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5143         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
5144         ASSERT(vd == vd->vdev_top);
5145 
5146         /*
5147          * Only remove any devices which are empty.
5148          */
5149         if (vd->vdev_stat.vs_alloc != 0)
5150                 return;
5151 
5152         (void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
5153 
5154         if (list_link_active(&vd->vdev_state_dirty_node))
5155                 vdev_state_clean(vd);
5156         if (list_link_active(&vd->vdev_config_dirty_node))
5157                 vdev_config_clean(vd);
5158 
5159         vdev_free(vd);
5160 
5161         if (last_vdev) {
5162                 vdev_compact_children(rvd);
5163         } else {
5164                 vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops);
5165                 vdev_add_child(rvd, vd);
5166         }
5167         vdev_config_dirty(rvd);
5168 
5169         /*
5170          * Reassess the health of our root vdev.
5171          */
5172         vdev_reopen(rvd);
5173 }
5174 
5175 /*
5176  * Remove a device from the pool -
5177  *
5178  * Removing a device from the vdev namespace requires several steps
5179  * and can take a significant amount of time.  As a result we use
5180  * the spa_vdev_config_[enter/exit] functions which allow us to
5181  * grab and release the spa_config_lock while still holding the namespace
5182  * lock.  During each step the configuration is synced out.
5183  *
5184  * Currently, this supports removing only hot spares, slogs, and level 2 ARC
5185  * devices.
5186  */
5187 int
5188 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
5189 {
5190         vdev_t *vd;
5191         metaslab_group_t *mg;
5192         nvlist_t **spares, **l2cache, *nv;
5193         uint64_t txg = 0;
5194         uint_t nspares, nl2cache;
5195         int error = 0;
5196         boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
5197 
5198         ASSERT(spa_writeable(spa));
5199 
5200         if (!locked)
5201                 txg = spa_vdev_enter(spa);
5202 
5203         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
5204 
5205         if (spa->spa_spares.sav_vdevs != NULL &&
5206             nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
5207             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
5208             (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
5209                 /*
5210                  * Only remove the hot spare if it's not currently in use
5211                  * in this pool.
5212                  */
5213                 if (vd == NULL || unspare) {
5214                         spa_vdev_remove_aux(spa->spa_spares.sav_config,
5215                             ZPOOL_CONFIG_SPARES, spares, nspares, nv);
5216                         spa_load_spares(spa);
5217                         spa->spa_spares.sav_sync = B_TRUE;
5218                 } else {
5219                         error = SET_ERROR(EBUSY);
5220                 }
5221         } else if (spa->spa_l2cache.sav_vdevs != NULL &&
5222             nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
5223             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
5224             (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
5225                 /*
5226                  * Cache devices can always be removed.
5227                  */
5228                 spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
5229                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
5230                 spa_load_l2cache(spa);
5231                 spa->spa_l2cache.sav_sync = B_TRUE;
5232         } else if (vd != NULL && vd->vdev_islog) {
5233                 ASSERT(!locked);
5234                 ASSERT(vd == vd->vdev_top);
5235 
5236                 /*
5237                  * XXX - Once we have bp-rewrite this should
5238                  * become the common case.
5239                  */
5240 
5241                 mg = vd->vdev_mg;
5242 
5243                 /*
5244                  * Stop allocating from this vdev.
5245                  */
5246                 metaslab_group_passivate(mg);
5247 
5248                 /*
5249                  * Wait for the youngest allocations and frees to sync,
5250                  * and then wait for the deferral of those frees to finish.
5251                  */
5252                 spa_vdev_config_exit(spa, NULL,
5253                     txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
5254 
5255                 /*
5256                  * Attempt to evacuate the vdev.
5257                  */
5258                 error = spa_vdev_remove_evacuate(spa, vd);
5259 
5260                 txg = spa_vdev_config_enter(spa);
5261 
5262                 /*
5263                  * If we couldn't evacuate the vdev, unwind.
5264                  */
5265                 if (error) {
5266                         metaslab_group_activate(mg);
5267                         return (spa_vdev_exit(spa, NULL, txg, error));
5268                 }
5269 
5270                 /*
5271                  * Clean up the vdev namespace.
5272                  */
5273                 spa_vdev_remove_from_namespace(spa, vd);
5274 
5275         } else if (vd != NULL) {
5276                 /*
5277                  * Normal vdevs cannot be removed (yet).
5278                  */
5279                 error = SET_ERROR(ENOTSUP);
5280         } else {
5281                 /*
5282                  * There is no vdev of any kind with the specified guid.
5283                  */
5284                 error = SET_ERROR(ENOENT);
5285         }
5286 
5287         if (!locked)
5288                 return (spa_vdev_exit(spa, NULL, txg, error));
5289 
5290         return (error);
5291 }
5292 
5293 /*
5294  * Find any device that's done replacing, or a vdev marked 'unspare' that's
5295  * currently spared, so we can detach it.
5296  */
5297 static vdev_t *
5298 spa_vdev_resilver_done_hunt(vdev_t *vd)
5299 {
5300         vdev_t *newvd, *oldvd;
5301 
5302         for (int c = 0; c < vd->vdev_children; c++) {
5303                 oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
5304                 if (oldvd != NULL)
5305                         return (oldvd);
5306         }
5307 
5308         /*
5309          * Check for a completed replacement.  We always consider the first
5310          * vdev in the list to be the oldest vdev, and the last one to be
5311          * the newest (see spa_vdev_attach() for how that works).  In
5312          * the case where the newest vdev is faulted, we will not automatically
5313          * remove it after a resilver completes.  This is OK as it will require
5314          * user intervention to determine which disk the admin wishes to keep.
5315          */
5316         if (vd->vdev_ops == &vdev_replacing_ops) {
5317                 ASSERT(vd->vdev_children > 1);
5318 
5319                 newvd = vd->vdev_child[vd->vdev_children - 1];
5320                 oldvd = vd->vdev_child[0];
5321 
5322                 if (vdev_dtl_empty(newvd, DTL_MISSING) &&
5323                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5324                     !vdev_dtl_required(oldvd))
5325                         return (oldvd);
5326         }
5327 
5328         /*
5329          * Check for a completed resilver with the 'unspare' flag set.
5330          */
5331         if (vd->vdev_ops == &vdev_spare_ops) {
5332                 vdev_t *first = vd->vdev_child[0];
5333                 vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
5334 
5335                 if (last->vdev_unspare) {
5336                         oldvd = first;
5337                         newvd = last;
5338                 } else if (first->vdev_unspare) {
5339                         oldvd = last;
5340                         newvd = first;
5341                 } else {
5342                         oldvd = NULL;
5343                 }
5344 
5345                 if (oldvd != NULL &&
5346                     vdev_dtl_empty(newvd, DTL_MISSING) &&
5347                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5348                     !vdev_dtl_required(oldvd))
5349                         return (oldvd);
5350 
5351                 /*
5352                  * If there are more than two spares attached to a disk,
5353                  * and those spares are not required, then we want to
5354                  * attempt to free them up now so that they can be used
5355                  * by other pools.  Once we're back down to a single
5356                  * disk+spare, we stop removing them.
5357                  */
5358                 if (vd->vdev_children > 2) {
5359                         newvd = vd->vdev_child[1];
5360 
5361                         if (newvd->vdev_isspare && last->vdev_isspare &&
5362                             vdev_dtl_empty(last, DTL_MISSING) &&
5363                             vdev_dtl_empty(last, DTL_OUTAGE) &&
5364                             !vdev_dtl_required(newvd))
5365                                 return (newvd);
5366                 }
5367         }
5368 
5369         return (NULL);
5370 }
5371 
5372 static void
5373 spa_vdev_resilver_done(spa_t *spa)
5374 {
5375         vdev_t *vd, *pvd, *ppvd;
5376         uint64_t guid, sguid, pguid, ppguid;
5377 
5378         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5379 
5380         while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
5381                 pvd = vd->vdev_parent;
5382                 ppvd = pvd->vdev_parent;
5383                 guid = vd->vdev_guid;
5384                 pguid = pvd->vdev_guid;
5385                 ppguid = ppvd->vdev_guid;
5386                 sguid = 0;
5387                 /*
5388                  * If we have just finished replacing a hot spared device, then
5389                  * we need to detach the parent's first child (the original hot
5390                  * spare) as well.
5391                  */
5392                 if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
5393                     ppvd->vdev_children == 2) {
5394                         ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
5395                         sguid = ppvd->vdev_child[1]->vdev_guid;
5396                 }
5397                 ASSERT(vd->vdev_resilver_txg == 0 || !vdev_dtl_required(vd));
5398 
5399                 spa_config_exit(spa, SCL_ALL, FTAG);
5400                 if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
5401                         return;
5402                 if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
5403                         return;
5404                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5405         }
5406 
5407         spa_config_exit(spa, SCL_ALL, FTAG);
5408 }
5409 
5410 /*
5411  * Update the stored path or FRU for this vdev.
5412  */
5413 int
5414 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
5415     boolean_t ispath)
5416 {
5417         vdev_t *vd;
5418         boolean_t sync = B_FALSE;
5419 
5420         ASSERT(spa_writeable(spa));
5421 
5422         spa_vdev_state_enter(spa, SCL_ALL);
5423 
5424         if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
5425                 return (spa_vdev_state_exit(spa, NULL, ENOENT));
5426 
5427         if (!vd->vdev_ops->vdev_op_leaf)
5428                 return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
5429 
5430         if (ispath) {
5431                 if (strcmp(value, vd->vdev_path) != 0) {
5432                         spa_strfree(vd->vdev_path);
5433                         vd->vdev_path = spa_strdup(value);
5434                         sync = B_TRUE;
5435                 }
5436         } else {
5437                 if (vd->vdev_fru == NULL) {
5438                         vd->vdev_fru = spa_strdup(value);
5439                         sync = B_TRUE;
5440                 } else if (strcmp(value, vd->vdev_fru) != 0) {
5441                         spa_strfree(vd->vdev_fru);
5442                         vd->vdev_fru = spa_strdup(value);
5443                         sync = B_TRUE;
5444                 }
5445         }
5446 
5447         return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
5448 }
5449 
5450 int
5451 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
5452 {
5453         return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
5454 }
5455 
5456 int
5457 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
5458 {
5459         return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
5460 }
5461 
5462 /*
5463  * ==========================================================================
5464  * SPA Scanning
5465  * ==========================================================================
5466  */
5467 
5468 int
5469 spa_scan_stop(spa_t *spa)
5470 {
5471         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5472         if (dsl_scan_resilvering(spa->spa_dsl_pool))
5473                 return (SET_ERROR(EBUSY));
5474         return (dsl_scan_cancel(spa->spa_dsl_pool));
5475 }
5476 
5477 int
5478 spa_scan(spa_t *spa, pool_scan_func_t func)
5479 {
5480         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5481 
5482         if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
5483                 return (SET_ERROR(ENOTSUP));
5484 
5485         /*
5486          * If a resilver was requested, but there is no DTL on a
5487          * writeable leaf device, we have nothing to do.
5488          */
5489         if (func == POOL_SCAN_RESILVER &&
5490             !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
5491                 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
5492                 return (0);
5493         }
5494 
5495         return (dsl_scan(spa->spa_dsl_pool, func));
5496 }
5497 
5498 /*
5499  * ==========================================================================
5500  * SPA async task processing
5501  * ==========================================================================
5502  */
5503 
5504 static void
5505 spa_async_remove(spa_t *spa, vdev_t *vd)
5506 {
5507         if (vd->vdev_remove_wanted) {
5508                 vd->vdev_remove_wanted = B_FALSE;
5509                 vd->vdev_delayed_close = B_FALSE;
5510                 vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
5511 
5512                 /*
5513                  * We want to clear the stats, but we don't want to do a full
5514                  * vdev_clear() as that will cause us to throw away
5515                  * degraded/faulted state as well as attempt to reopen the
5516                  * device, all of which is a waste.
5517                  */
5518                 vd->vdev_stat.vs_read_errors = 0;
5519                 vd->vdev_stat.vs_write_errors = 0;
5520                 vd->vdev_stat.vs_checksum_errors = 0;
5521 
5522                 vdev_state_dirty(vd->vdev_top);
5523         }
5524 
5525         for (int c = 0; c < vd->vdev_children; c++)
5526                 spa_async_remove(spa, vd->vdev_child[c]);
5527 }
5528 
5529 static void
5530 spa_async_probe(spa_t *spa, vdev_t *vd)
5531 {
5532         if (vd->vdev_probe_wanted) {
5533                 vd->vdev_probe_wanted = B_FALSE;
5534                 vdev_reopen(vd);        /* vdev_open() does the actual probe */
5535         }
5536 
5537         for (int c = 0; c < vd->vdev_children; c++)
5538                 spa_async_probe(spa, vd->vdev_child[c]);
5539 }
5540 
5541 static void
5542 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
5543 {
5544         sysevent_id_t eid;
5545         nvlist_t *attr;
5546         char *physpath;
5547 
5548         if (!spa->spa_autoexpand)
5549                 return;
5550 
5551         for (int c = 0; c < vd->vdev_children; c++) {
5552                 vdev_t *cvd = vd->vdev_child[c];
5553                 spa_async_autoexpand(spa, cvd);
5554         }
5555 
5556         if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
5557                 return;
5558 
5559         physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
5560         (void) snprintf(physpath, MAXPATHLEN, "/devices%s", vd->vdev_physpath);
5561 
5562         VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5563         VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
5564 
5565         (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
5566             ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
5567 
5568         nvlist_free(attr);
5569         kmem_free(physpath, MAXPATHLEN);
5570 }
5571 
5572 static void
5573 spa_async_thread(spa_t *spa)
5574 {
5575         int tasks;
5576 
5577         ASSERT(spa->spa_sync_on);
5578 
5579         mutex_enter(&spa->spa_async_lock);
5580         tasks = spa->spa_async_tasks;
5581         spa->spa_async_tasks = 0;
5582         mutex_exit(&spa->spa_async_lock);
5583 
5584         /*
5585          * See if the config needs to be updated.
5586          */
5587         if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
5588                 uint64_t old_space, new_space;
5589 
5590                 mutex_enter(&spa_namespace_lock);
5591                 old_space = metaslab_class_get_space(spa_normal_class(spa));
5592                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
5593                 new_space = metaslab_class_get_space(spa_normal_class(spa));
5594                 mutex_exit(&spa_namespace_lock);
5595 
5596                 /*
5597                  * If the pool grew as a result of the config update,
5598                  * then log an internal history event.
5599                  */
5600                 if (new_space != old_space) {
5601                         spa_history_log_internal(spa, "vdev online", NULL,
5602                             "pool '%s' size: %llu(+%llu)",
5603                             spa_name(spa), new_space, new_space - old_space);
5604                 }
5605         }
5606 
5607         /*
5608          * See if any devices need to be marked REMOVED.
5609          */
5610         if (tasks & SPA_ASYNC_REMOVE) {
5611                 spa_vdev_state_enter(spa, SCL_NONE);
5612                 spa_async_remove(spa, spa->spa_root_vdev);
5613                 for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
5614                         spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
5615                 for (int i = 0; i < spa->spa_spares.sav_count; i++)
5616                         spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
5617                 (void) spa_vdev_state_exit(spa, NULL, 0);
5618         }
5619 
5620         if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
5621                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5622                 spa_async_autoexpand(spa, spa->spa_root_vdev);
5623                 spa_config_exit(spa, SCL_CONFIG, FTAG);
5624         }
5625 
5626         /*
5627          * See if any devices need to be probed.
5628          */
5629         if (tasks & SPA_ASYNC_PROBE) {
5630                 spa_vdev_state_enter(spa, SCL_NONE);
5631                 spa_async_probe(spa, spa->spa_root_vdev);
5632                 (void) spa_vdev_state_exit(spa, NULL, 0);
5633         }
5634 
5635         /*
5636          * If any devices are done replacing, detach them.
5637          */
5638         if (tasks & SPA_ASYNC_RESILVER_DONE)
5639                 spa_vdev_resilver_done(spa);
5640 
5641         /*
5642          * Kick off a resilver.
5643          */
5644         if (tasks & SPA_ASYNC_RESILVER)
5645                 dsl_resilver_restart(spa->spa_dsl_pool, 0);
5646 
5647         /*
5648          * Let the world know that we're done.
5649          */
5650         mutex_enter(&spa->spa_async_lock);
5651         spa->spa_async_thread = NULL;
5652         cv_broadcast(&spa->spa_async_cv);
5653         mutex_exit(&spa->spa_async_lock);
5654         thread_exit();
5655 }
5656 
5657 void
5658 spa_async_suspend(spa_t *spa)
5659 {
5660         mutex_enter(&spa->spa_async_lock);
5661         spa->spa_async_suspended++;
5662         while (spa->spa_async_thread != NULL)
5663                 cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
5664         mutex_exit(&spa->spa_async_lock);
5665 }
5666 
5667 void
5668 spa_async_resume(spa_t *spa)
5669 {
5670         mutex_enter(&spa->spa_async_lock);
5671         ASSERT(spa->spa_async_suspended != 0);
5672         spa->spa_async_suspended--;
5673         mutex_exit(&spa->spa_async_lock);
5674 }
5675 
5676 static boolean_t
5677 spa_async_tasks_pending(spa_t *spa)
5678 {
5679         uint_t non_config_tasks;
5680         uint_t config_task;
5681         boolean_t config_task_suspended;
5682 
5683         non_config_tasks = spa->spa_async_tasks & ~SPA_ASYNC_CONFIG_UPDATE;
5684         config_task = spa->spa_async_tasks & SPA_ASYNC_CONFIG_UPDATE;
5685         if (spa->spa_ccw_fail_time == 0) {
5686                 config_task_suspended = B_FALSE;
5687         } else {
5688                 config_task_suspended =
5689                     (gethrtime() - spa->spa_ccw_fail_time) <
5690                     (zfs_ccw_retry_interval * NANOSEC);
5691         }
5692 
5693         return (non_config_tasks || (config_task && !config_task_suspended));
5694 }
5695 
5696 static void
5697 spa_async_dispatch(spa_t *spa)
5698 {
5699         mutex_enter(&spa->spa_async_lock);
5700         if (spa_async_tasks_pending(spa) &&
5701             !spa->spa_async_suspended &&
5702             spa->spa_async_thread == NULL &&
5703             rootdir != NULL)
5704                 spa->spa_async_thread = thread_create(NULL, 0,
5705                     spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
5706         mutex_exit(&spa->spa_async_lock);
5707 }
5708 
5709 void
5710 spa_async_request(spa_t *spa, int task)
5711 {
5712         zfs_dbgmsg("spa=%s async request task=%u", spa->spa_name, task);
5713         mutex_enter(&spa->spa_async_lock);
5714         spa->spa_async_tasks |= task;
5715         mutex_exit(&spa->spa_async_lock);
5716 }
5717 
5718 /*
5719  * ==========================================================================
5720  * SPA syncing routines
5721  * ==========================================================================
5722  */
5723 
5724 static int
5725 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5726 {
5727         bpobj_t *bpo = arg;
5728         bpobj_enqueue(bpo, bp, tx);
5729         return (0);
5730 }
5731 
5732 static int
5733 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5734 {
5735         zio_t *zio = arg;
5736 
5737         zio_nowait(zio_free_sync(zio, zio->io_spa, dmu_tx_get_txg(tx), bp,
5738             zio->io_flags));
5739         return (0);
5740 }
5741 
5742 /*
5743  * Note: this simple function is not inlined to make it easier to dtrace the
5744  * amount of time spent syncing frees.
5745  */
5746 static void
5747 spa_sync_frees(spa_t *spa, bplist_t *bpl, dmu_tx_t *tx)
5748 {
5749         zio_t *zio = zio_root(spa, NULL, NULL, 0);
5750         bplist_iterate(bpl, spa_free_sync_cb, zio, tx);
5751         VERIFY(zio_wait(zio) == 0);
5752 }
5753 
5754 /*
5755  * Note: this simple function is not inlined to make it easier to dtrace the
5756  * amount of time spent syncing deferred frees.
5757  */
5758 static void
5759 spa_sync_deferred_frees(spa_t *spa, dmu_tx_t *tx)
5760 {
5761         zio_t *zio = zio_root(spa, NULL, NULL, 0);
5762         VERIFY3U(bpobj_iterate(&spa->spa_deferred_bpobj,
5763             spa_free_sync_cb, zio, tx), ==, 0);
5764         VERIFY0(zio_wait(zio));
5765 }
5766 
5767 
5768 static void
5769 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
5770 {
5771         char *packed = NULL;
5772         size_t bufsize;
5773         size_t nvsize = 0;
5774         dmu_buf_t *db;
5775 
5776         VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
5777 
5778         /*
5779          * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
5780          * information.  This avoids the dbuf_will_dirty() path and
5781          * saves us a pre-read to get data we don't actually care about.
5782          */
5783         bufsize = P2ROUNDUP((uint64_t)nvsize, SPA_CONFIG_BLOCKSIZE);
5784         packed = kmem_alloc(bufsize, KM_SLEEP);
5785 
5786         VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
5787             KM_SLEEP) == 0);
5788         bzero(packed + nvsize, bufsize - nvsize);
5789 
5790         dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
5791 
5792         kmem_free(packed, bufsize);
5793 
5794         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
5795         dmu_buf_will_dirty(db, tx);
5796         *(uint64_t *)db->db_data = nvsize;
5797         dmu_buf_rele(db, FTAG);
5798 }
5799 
5800 static void
5801 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
5802     const char *config, const char *entry)
5803 {
5804         nvlist_t *nvroot;
5805         nvlist_t **list;
5806         int i;
5807 
5808         if (!sav->sav_sync)
5809                 return;
5810 
5811         /*
5812          * Update the MOS nvlist describing the list of available devices.
5813          * spa_validate_aux() will have already made sure this nvlist is
5814          * valid and the vdevs are labeled appropriately.
5815          */
5816         if (sav->sav_object == 0) {
5817                 sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
5818                     DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
5819                     sizeof (uint64_t), tx);
5820                 VERIFY(zap_update(spa->spa_meta_objset,
5821                     DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
5822                     &sav->sav_object, tx) == 0);
5823         }
5824 
5825         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5826         if (sav->sav_count == 0) {
5827                 VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
5828         } else {
5829                 list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
5830                 for (i = 0; i < sav->sav_count; i++)
5831                         list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
5832                             B_FALSE, VDEV_CONFIG_L2CACHE);
5833                 VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
5834                     sav->sav_count) == 0);
5835                 for (i = 0; i < sav->sav_count; i++)
5836                         nvlist_free(list[i]);
5837                 kmem_free(list, sav->sav_count * sizeof (void *));
5838         }
5839 
5840         spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
5841         nvlist_free(nvroot);
5842 
5843         sav->sav_sync = B_FALSE;
5844 }
5845 
5846 static void
5847 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
5848 {
5849         nvlist_t *config;
5850 
5851         if (list_is_empty(&spa->spa_config_dirty_list))
5852                 return;
5853 
5854         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5855 
5856         config = spa_config_generate(spa, spa->spa_root_vdev,
5857             dmu_tx_get_txg(tx), B_FALSE);
5858 
5859         /*
5860          * If we're upgrading the spa version then make sure that
5861          * the config object gets updated with the correct version.
5862          */
5863         if (spa->spa_ubsync.ub_version < spa->spa_uberblock.ub_version)
5864                 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
5865                     spa->spa_uberblock.ub_version);
5866 
5867         spa_config_exit(spa, SCL_STATE, FTAG);
5868 
5869         if (spa->spa_config_syncing)
5870                 nvlist_free(spa->spa_config_syncing);
5871         spa->spa_config_syncing = config;
5872 
5873         spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
5874 }
5875 
5876 static void
5877 spa_sync_version(void *arg, dmu_tx_t *tx)
5878 {
5879         uint64_t *versionp = arg;
5880         uint64_t version = *versionp;
5881         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5882 
5883         /*
5884          * Setting the version is special cased when first creating the pool.
5885          */
5886         ASSERT(tx->tx_txg != TXG_INITIAL);
5887 
5888         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
5889         ASSERT(version >= spa_version(spa));
5890 
5891         spa->spa_uberblock.ub_version = version;
5892         vdev_config_dirty(spa->spa_root_vdev);
5893         spa_history_log_internal(spa, "set", tx, "version=%lld", version);
5894 }
5895 
5896 /*
5897  * Set zpool properties.
5898  */
5899 static void
5900 spa_sync_props(void *arg, dmu_tx_t *tx)
5901 {
5902         nvlist_t *nvp = arg;
5903         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5904         objset_t *mos = spa->spa_meta_objset;
5905         nvpair_t *elem = NULL;
5906 
5907         mutex_enter(&spa->spa_props_lock);
5908 
5909         while ((elem = nvlist_next_nvpair(nvp, elem))) {
5910                 uint64_t intval;
5911                 char *strval, *fname;
5912                 zpool_prop_t prop;
5913                 const char *propname;
5914                 zprop_type_t proptype;
5915                 spa_feature_t fid;
5916 
5917                 switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
5918                 case ZPROP_INVAL:
5919                         /*
5920                          * We checked this earlier in spa_prop_validate().
5921                          */
5922                         ASSERT(zpool_prop_feature(nvpair_name(elem)));
5923 
5924                         fname = strchr(nvpair_name(elem), '@') + 1;
5925                         VERIFY0(zfeature_lookup_name(fname, &fid));
5926 
5927                         spa_feature_enable(spa, fid, tx);
5928                         spa_history_log_internal(spa, "set", tx,
5929                             "%s=enabled", nvpair_name(elem));
5930                         break;
5931 
5932                 case ZPOOL_PROP_VERSION:
5933                         intval = fnvpair_value_uint64(elem);
5934                         /*
5935                          * The version is synced seperatly before other
5936                          * properties and should be correct by now.
5937                          */
5938                         ASSERT3U(spa_version(spa), >=, intval);
5939                         break;
5940 
5941                 case ZPOOL_PROP_ALTROOT:
5942                         /*
5943                          * 'altroot' is a non-persistent property. It should
5944                          * have been set temporarily at creation or import time.
5945                          */
5946                         ASSERT(spa->spa_root != NULL);
5947                         break;
5948 
5949                 case ZPOOL_PROP_READONLY:
5950                 case ZPOOL_PROP_CACHEFILE:
5951                         /*
5952                          * 'readonly' and 'cachefile' are also non-persisitent
5953                          * properties.
5954                          */
5955                         break;
5956                 case ZPOOL_PROP_COMMENT:
5957                         strval = fnvpair_value_string(elem);
5958                         if (spa->spa_comment != NULL)
5959                                 spa_strfree(spa->spa_comment);
5960                         spa->spa_comment = spa_strdup(strval);
5961                         /*
5962                          * We need to dirty the configuration on all the vdevs
5963                          * so that their labels get updated.  It's unnecessary
5964                          * to do this for pool creation since the vdev's
5965                          * configuratoin has already been dirtied.
5966                          */
5967                         if (tx->tx_txg != TXG_INITIAL)
5968                                 vdev_config_dirty(spa->spa_root_vdev);
5969                         spa_history_log_internal(spa, "set", tx,
5970                             "%s=%s", nvpair_name(elem), strval);
5971                         break;
5972                 default:
5973                         /*
5974                          * Set pool property values in the poolprops mos object.
5975                          */
5976                         if (spa->spa_pool_props_object == 0) {
5977                                 spa->spa_pool_props_object =
5978                                     zap_create_link(mos, DMU_OT_POOL_PROPS,
5979                                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
5980                                     tx);
5981                         }
5982 
5983                         /* normalize the property name */
5984                         propname = zpool_prop_to_name(prop);
5985                         proptype = zpool_prop_get_type(prop);
5986 
5987                         if (nvpair_type(elem) == DATA_TYPE_STRING) {
5988                                 ASSERT(proptype == PROP_TYPE_STRING);
5989                                 strval = fnvpair_value_string(elem);
5990                                 VERIFY0(zap_update(mos,
5991                                     spa->spa_pool_props_object, propname,
5992                                     1, strlen(strval) + 1, strval, tx));
5993                                 spa_history_log_internal(spa, "set", tx,
5994                                     "%s=%s", nvpair_name(elem), strval);
5995                         } else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
5996                                 intval = fnvpair_value_uint64(elem);
5997 
5998                                 if (proptype == PROP_TYPE_INDEX) {
5999                                         const char *unused;
6000                                         VERIFY0(zpool_prop_index_to_string(
6001                                             prop, intval, &unused));
6002                                 }
6003                                 VERIFY0(zap_update(mos,
6004                                     spa->spa_pool_props_object, propname,
6005                                     8, 1, &intval, tx));
6006                                 spa_history_log_internal(spa, "set", tx,
6007                                     "%s=%lld", nvpair_name(elem), intval);
6008                         } else {
6009                                 ASSERT(0); /* not allowed */
6010                         }
6011 
6012                         switch (prop) {
6013                         case ZPOOL_PROP_DELEGATION:
6014                                 spa->spa_delegation = intval;
6015                                 break;
6016                         case ZPOOL_PROP_BOOTFS:
6017                                 spa->spa_bootfs = intval;
6018                                 break;
6019                         case ZPOOL_PROP_FAILUREMODE:
6020                                 spa->spa_failmode = intval;
6021                                 break;
6022                         case ZPOOL_PROP_AUTOEXPAND:
6023                                 spa->spa_autoexpand = intval;
6024                                 if (tx->tx_txg != TXG_INITIAL)
6025                                         spa_async_request(spa,
6026                                             SPA_ASYNC_AUTOEXPAND);
6027                                 break;
6028                         case ZPOOL_PROP_DEDUPDITTO:
6029                                 spa->spa_dedup_ditto = intval;
6030                                 break;
6031                         default:
6032                                 break;
6033                         }
6034                 }
6035 
6036         }
6037 
6038         mutex_exit(&spa->spa_props_lock);
6039 }
6040 
6041 /*
6042  * Perform one-time upgrade on-disk changes.  spa_version() does not
6043  * reflect the new version this txg, so there must be no changes this
6044  * txg to anything that the upgrade code depends on after it executes.
6045  * Therefore this must be called after dsl_pool_sync() does the sync
6046  * tasks.
6047  */
6048 static void
6049 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
6050 {
6051         dsl_pool_t *dp = spa->spa_dsl_pool;
6052 
6053         ASSERT(spa->spa_sync_pass == 1);
6054 
6055         rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
6056 
6057         if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
6058             spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
6059                 dsl_pool_create_origin(dp, tx);
6060 
6061                 /* Keeping the origin open increases spa_minref */
6062                 spa->spa_minref += 3;
6063         }
6064 
6065         if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
6066             spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
6067                 dsl_pool_upgrade_clones(dp, tx);
6068         }
6069 
6070         if (spa->spa_ubsync.ub_version < SPA_VERSION_DIR_CLONES &&
6071             spa->spa_uberblock.ub_version >= SPA_VERSION_DIR_CLONES) {
6072                 dsl_pool_upgrade_dir_clones(dp, tx);
6073 
6074                 /* Keeping the freedir open increases spa_minref */
6075                 spa->spa_minref += 3;
6076         }
6077 
6078         if (spa->spa_ubsync.ub_version < SPA_VERSION_FEATURES &&
6079             spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
6080                 spa_feature_create_zap_objects(spa, tx);
6081         }
6082         rrw_exit(&dp->dp_config_rwlock, FTAG);
6083 }
6084 
6085 /*
6086  * Sync the specified transaction group.  New blocks may be dirtied as
6087  * part of the process, so we iterate until it converges.
6088  */
6089 void
6090 spa_sync(spa_t *spa, uint64_t txg)
6091 {
6092         dsl_pool_t *dp = spa->spa_dsl_pool;
6093         objset_t *mos = spa->spa_meta_objset;
6094         bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
6095         vdev_t *rvd = spa->spa_root_vdev;
6096         vdev_t *vd;
6097         dmu_tx_t *tx;
6098         int error;
6099 
6100         VERIFY(spa_writeable(spa));
6101 
6102         /*
6103          * Lock out configuration changes.
6104          */
6105         spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
6106 
6107         spa->spa_syncing_txg = txg;
6108         spa->spa_sync_pass = 0;
6109 
6110         /*
6111          * If there are any pending vdev state changes, convert them
6112          * into config changes that go out with this transaction group.
6113          */
6114         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6115         while (list_head(&spa->spa_state_dirty_list) != NULL) {
6116                 /*
6117                  * We need the write lock here because, for aux vdevs,
6118                  * calling vdev_config_dirty() modifies sav_config.
6119                  * This is ugly and will become unnecessary when we
6120                  * eliminate the aux vdev wart by integrating all vdevs
6121                  * into the root vdev tree.
6122                  */
6123                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6124                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
6125                 while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
6126                         vdev_state_clean(vd);
6127                         vdev_config_dirty(vd);
6128                 }
6129                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6130                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
6131         }
6132         spa_config_exit(spa, SCL_STATE, FTAG);
6133 
6134         tx = dmu_tx_create_assigned(dp, txg);
6135 
6136         spa->spa_sync_starttime = gethrtime();
6137         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid,
6138             spa->spa_sync_starttime + spa->spa_deadman_synctime));
6139 
6140         /*
6141          * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
6142          * set spa_deflate if we have no raid-z vdevs.
6143          */
6144         if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
6145             spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
6146                 int i;
6147 
6148                 for (i = 0; i < rvd->vdev_children; i++) {
6149                         vd = rvd->vdev_child[i];
6150                         if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
6151                                 break;
6152                 }
6153                 if (i == rvd->vdev_children) {
6154                         spa->spa_deflate = TRUE;
6155                         VERIFY(0 == zap_add(spa->spa_meta_objset,
6156                             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
6157                             sizeof (uint64_t), 1, &spa->spa_deflate, tx));
6158                 }
6159         }
6160 
6161         /*
6162          * If anything has changed in this txg, or if someone is waiting
6163          * for this txg to sync (eg, spa_vdev_remove()), push the
6164          * deferred frees from the previous txg.  If not, leave them
6165          * alone so that we don't generate work on an otherwise idle
6166          * system.
6167          */
6168         if (!txg_list_empty(&dp->dp_dirty_datasets, txg) ||
6169             !txg_list_empty(&dp->dp_dirty_dirs, txg) ||
6170             !txg_list_empty(&dp->dp_sync_tasks, txg) ||
6171             ((dsl_scan_active(dp->dp_scan) ||
6172             txg_sync_waiting(dp)) && !spa_shutting_down(spa))) {
6173                 spa_sync_deferred_frees(spa, tx);
6174         }
6175 
6176         /*
6177          * Iterate to convergence.
6178          */
6179         do {
6180                 int pass = ++spa->spa_sync_pass;
6181 
6182                 spa_sync_config_object(spa, tx);
6183                 spa_sync_aux_dev(spa, &spa->spa_spares, tx,
6184                     ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
6185                 spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
6186                     ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
6187                 spa_errlog_sync(spa, txg);
6188                 dsl_pool_sync(dp, txg);
6189 
6190                 if (pass < zfs_sync_pass_deferred_free) {
6191                         spa_sync_frees(spa, free_bpl, tx);
6192                 } else {
6193                         bplist_iterate(free_bpl, bpobj_enqueue_cb,
6194                             &spa->spa_deferred_bpobj, tx);
6195                 }
6196 
6197                 ddt_sync(spa, txg);
6198                 dsl_scan_sync(dp, tx);
6199 
6200                 while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
6201                         vdev_sync(vd, txg);
6202 
6203                 if (pass == 1)
6204                         spa_sync_upgrades(spa, tx);
6205 
6206         } while (dmu_objset_is_dirty(mos, txg));
6207 
6208         /*
6209          * Rewrite the vdev configuration (which includes the uberblock)
6210          * to commit the transaction group.
6211          *
6212          * If there are no dirty vdevs, we sync the uberblock to a few
6213          * random top-level vdevs that are known to be visible in the
6214          * config cache (see spa_vdev_add() for a complete description).
6215          * If there *are* dirty vdevs, sync the uberblock to all vdevs.
6216          */
6217         for (;;) {
6218                 /*
6219                  * We hold SCL_STATE to prevent vdev open/close/etc.
6220                  * while we're attempting to write the vdev labels.
6221                  */
6222                 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6223 
6224                 if (list_is_empty(&spa->spa_config_dirty_list)) {
6225                         vdev_t *svd[SPA_DVAS_PER_BP];
6226                         int svdcount = 0;
6227                         int children = rvd->vdev_children;
6228                         int c0 = spa_get_random(children);
6229 
6230                         for (int c = 0; c < children; c++) {
6231                                 vd = rvd->vdev_child[(c0 + c) % children];
6232                                 if (vd->vdev_ms_array == 0 || vd->vdev_islog)
6233                                         continue;
6234                                 svd[svdcount++] = vd;
6235                                 if (svdcount == SPA_DVAS_PER_BP)
6236                                         break;
6237                         }
6238                         error = vdev_config_sync(svd, svdcount, txg, B_FALSE);
6239                         if (error != 0)
6240                                 error = vdev_config_sync(svd, svdcount, txg,
6241                                     B_TRUE);
6242                 } else {
6243                         error = vdev_config_sync(rvd->vdev_child,
6244                             rvd->vdev_children, txg, B_FALSE);
6245                         if (error != 0)
6246                                 error = vdev_config_sync(rvd->vdev_child,
6247                                     rvd->vdev_children, txg, B_TRUE);
6248                 }
6249 
6250                 if (error == 0)
6251                         spa->spa_last_synced_guid = rvd->vdev_guid;
6252 
6253                 spa_config_exit(spa, SCL_STATE, FTAG);
6254 
6255                 if (error == 0)
6256                         break;
6257                 zio_suspend(spa, NULL);
6258                 zio_resume_wait(spa);
6259         }
6260         dmu_tx_commit(tx);
6261 
6262         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
6263 
6264         /*
6265          * Clear the dirty config list.
6266          */
6267         while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
6268                 vdev_config_clean(vd);
6269 
6270         /*
6271          * Now that the new config has synced transactionally,
6272          * let it become visible to the config cache.
6273          */
6274         if (spa->spa_config_syncing != NULL) {
6275                 spa_config_set(spa, spa->spa_config_syncing);
6276                 spa->spa_config_txg = txg;
6277                 spa->spa_config_syncing = NULL;
6278         }
6279 
6280         spa->spa_ubsync = spa->spa_uberblock;
6281 
6282         dsl_pool_sync_done(dp, txg);
6283 
6284         /*
6285          * Update usable space statistics.
6286          */
6287         while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
6288                 vdev_sync_done(vd, txg);
6289 
6290         spa_update_dspace(spa);
6291 
6292         /*
6293          * It had better be the case that we didn't dirty anything
6294          * since vdev_config_sync().
6295          */
6296         ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
6297         ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
6298         ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
6299 
6300         spa->spa_sync_pass = 0;
6301 
6302         spa_config_exit(spa, SCL_CONFIG, FTAG);
6303 
6304         spa_handle_ignored_writes(spa);
6305 
6306         /*
6307          * If any async tasks have been requested, kick them off.
6308          */
6309         spa_async_dispatch(spa);
6310 }
6311 
6312 /*
6313  * Sync all pools.  We don't want to hold the namespace lock across these
6314  * operations, so we take a reference on the spa_t and drop the lock during the
6315  * sync.
6316  */
6317 void
6318 spa_sync_allpools(void)
6319 {
6320         spa_t *spa = NULL;
6321         mutex_enter(&spa_namespace_lock);
6322         while ((spa = spa_next(spa)) != NULL) {
6323                 if (spa_state(spa) != POOL_STATE_ACTIVE ||
6324                     !spa_writeable(spa) || spa_suspended(spa))
6325                         continue;
6326                 spa_open_ref(spa, FTAG);
6327                 mutex_exit(&spa_namespace_lock);
6328                 txg_wait_synced(spa_get_dsl(spa), 0);
6329                 mutex_enter(&spa_namespace_lock);
6330                 spa_close(spa, FTAG);
6331         }
6332         mutex_exit(&spa_namespace_lock);
6333 }
6334 
6335 /*
6336  * ==========================================================================
6337  * Miscellaneous routines
6338  * ==========================================================================
6339  */
6340 
6341 /*
6342  * Remove all pools in the system.
6343  */
6344 void
6345 spa_evict_all(void)
6346 {
6347         spa_t *spa;
6348 
6349         /*
6350          * Remove all cached state.  All pools should be closed now,
6351          * so every spa in the AVL tree should be unreferenced.
6352          */
6353         mutex_enter(&spa_namespace_lock);
6354         while ((spa = spa_next(NULL)) != NULL) {
6355                 /*
6356                  * Stop async tasks.  The async thread may need to detach
6357                  * a device that's been replaced, which requires grabbing
6358                  * spa_namespace_lock, so we must drop it here.
6359                  */
6360                 spa_open_ref(spa, FTAG);
6361                 mutex_exit(&spa_namespace_lock);
6362                 spa_async_suspend(spa);
6363                 mutex_enter(&spa_namespace_lock);
6364                 spa_close(spa, FTAG);
6365 
6366                 if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
6367                         spa_unload(spa);
6368                         spa_deactivate(spa);
6369                 }
6370                 spa_remove(spa);
6371         }
6372         mutex_exit(&spa_namespace_lock);
6373 }
6374 
6375 vdev_t *
6376 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
6377 {
6378         vdev_t *vd;
6379         int i;
6380 
6381         if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
6382                 return (vd);
6383 
6384         if (aux) {
6385                 for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
6386                         vd = spa->spa_l2cache.sav_vdevs[i];
6387                         if (vd->vdev_guid == guid)
6388                                 return (vd);
6389                 }
6390 
6391                 for (i = 0; i < spa->spa_spares.sav_count; i++) {
6392                         vd = spa->spa_spares.sav_vdevs[i];
6393                         if (vd->vdev_guid == guid)
6394                                 return (vd);
6395                 }
6396         }
6397 
6398         return (NULL);
6399 }
6400 
6401 void
6402 spa_upgrade(spa_t *spa, uint64_t version)
6403 {
6404         ASSERT(spa_writeable(spa));
6405 
6406         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6407 
6408         /*
6409          * This should only be called for a non-faulted pool, and since a
6410          * future version would result in an unopenable pool, this shouldn't be
6411          * possible.
6412          */
6413         ASSERT(SPA_VERSION_IS_SUPPORTED(spa->spa_uberblock.ub_version));
6414         ASSERT(version >= spa->spa_uberblock.ub_version);
6415 
6416         spa->spa_uberblock.ub_version = version;
6417         vdev_config_dirty(spa->spa_root_vdev);
6418 
6419         spa_config_exit(spa, SCL_ALL, FTAG);
6420 
6421         txg_wait_synced(spa_get_dsl(spa), 0);
6422 }
6423 
6424 boolean_t
6425 spa_has_spare(spa_t *spa, uint64_t guid)
6426 {
6427         int i;
6428         uint64_t spareguid;
6429         spa_aux_vdev_t *sav = &spa->spa_spares;
6430 
6431         for (i = 0; i < sav->sav_count; i++)
6432                 if (sav->sav_vdevs[i]->vdev_guid == guid)
6433                         return (B_TRUE);
6434 
6435         for (i = 0; i < sav->sav_npending; i++) {
6436                 if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
6437                     &spareguid) == 0 && spareguid == guid)
6438                         return (B_TRUE);
6439         }
6440 
6441         return (B_FALSE);
6442 }
6443 
6444 /*
6445  * Check if a pool has an active shared spare device.
6446  * Note: reference count of an active spare is 2, as a spare and as a replace
6447  */
6448 static boolean_t
6449 spa_has_active_shared_spare(spa_t *spa)
6450 {
6451         int i, refcnt;
6452         uint64_t pool;
6453         spa_aux_vdev_t *sav = &spa->spa_spares;
6454 
6455         for (i = 0; i < sav->sav_count; i++) {
6456                 if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
6457                     &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
6458                     refcnt > 2)
6459                         return (B_TRUE);
6460         }
6461 
6462         return (B_FALSE);
6463 }
6464 
6465 /*
6466  * Post a sysevent corresponding to the given event.  The 'name' must be one of
6467  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
6468  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
6469  * in the userland libzpool, as we don't want consumers to misinterpret ztest
6470  * or zdb as real changes.
6471  */
6472 void
6473 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
6474 {
6475 #ifdef _KERNEL
6476         sysevent_t              *ev;
6477         sysevent_attr_list_t    *attr = NULL;
6478         sysevent_value_t        value;
6479         sysevent_id_t           eid;
6480 
6481         ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
6482             SE_SLEEP);
6483 
6484         value.value_type = SE_DATA_TYPE_STRING;
6485         value.value.sv_string = spa_name(spa);
6486         if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
6487                 goto done;
6488 
6489         value.value_type = SE_DATA_TYPE_UINT64;
6490         value.value.sv_uint64 = spa_guid(spa);
6491         if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
6492                 goto done;
6493 
6494         if (vd) {
6495                 value.value_type = SE_DATA_TYPE_UINT64;
6496                 value.value.sv_uint64 = vd->vdev_guid;
6497                 if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
6498                     SE_SLEEP) != 0)
6499                         goto done;
6500 
6501                 if (vd->vdev_path) {
6502                         value.value_type = SE_DATA_TYPE_STRING;
6503                         value.value.sv_string = vd->vdev_path;
6504                         if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
6505                             &value, SE_SLEEP) != 0)
6506                                 goto done;
6507                 }
6508         }
6509 
6510         if (sysevent_attach_attributes(ev, attr) != 0)
6511                 goto done;
6512         attr = NULL;
6513 
6514         (void) log_sysevent(ev, SE_SLEEP, &eid);
6515 
6516 done:
6517         if (attr)
6518                 sysevent_free_attr(attr);
6519         sysevent_free(ev);
6520 #endif
6521 }