5045 use atomic_{inc,dec}_* instead of atomic_add_*

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright (c) 2011, 2014 by Delphix. All rights reserved.
  25  * Copyright (c) 2013, 2014, Nexenta Systems, Inc.  All rights reserved.
  26  */
  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_P(12, 8),   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                 /*
 245                  * The $FREE directory was introduced in SPA_VERSION_DEADLISTS,
 246                  * when opening pools before this version freedir will be NULL.
 247                  */
 248                 if (pool->dp_free_dir != NULL) {
 249                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING, NULL,
 250                             pool->dp_free_dir->dd_phys->dd_used_bytes, src);
 251                 } else {
 252                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING,
 253                             NULL, 0, src);
 254                 }
 255 
 256                 if (pool->dp_leak_dir != NULL) {
 257                         spa_prop_add_list(*nvp, ZPOOL_PROP_LEAKED, NULL,
 258                             pool->dp_leak_dir->dd_phys->dd_used_bytes, src);
 259                 } else {
 260                         spa_prop_add_list(*nvp, ZPOOL_PROP_LEAKED,
 261                             NULL, 0, src);
 262                 }
 263         }
 264 
 265         spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
 266 
 267         if (spa->spa_comment != NULL) {
 268                 spa_prop_add_list(*nvp, ZPOOL_PROP_COMMENT, spa->spa_comment,
 269                     0, ZPROP_SRC_LOCAL);
 270         }
 271 
 272         if (spa->spa_root != NULL)
 273                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
 274                     0, ZPROP_SRC_LOCAL);
 275 
 276         if ((dp = list_head(&spa->spa_config_list)) != NULL) {
 277                 if (dp->scd_path == NULL) {
 278                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 279                             "none", 0, ZPROP_SRC_LOCAL);
 280                 } else if (strcmp(dp->scd_path, spa_config_path) != 0) {
 281                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 282                             dp->scd_path, 0, ZPROP_SRC_LOCAL);
 283                 }
 284         }
 285 }
 286 
 287 /*
 288  * Get zpool property values.
 289  */
 290 int
 291 spa_prop_get(spa_t *spa, nvlist_t **nvp)
 292 {
 293         objset_t *mos = spa->spa_meta_objset;
 294         zap_cursor_t zc;
 295         zap_attribute_t za;
 296         int err;
 297 
 298         VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 299 
 300         mutex_enter(&spa->spa_props_lock);
 301 
 302         /*
 303          * Get properties from the spa config.
 304          */
 305         spa_prop_get_config(spa, nvp);
 306 
 307         /* If no pool property object, no more prop to get. */
 308         if (mos == NULL || spa->spa_pool_props_object == 0) {
 309                 mutex_exit(&spa->spa_props_lock);
 310                 return (0);
 311         }
 312 
 313         /*
 314          * Get properties from the MOS pool property object.
 315          */
 316         for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
 317             (err = zap_cursor_retrieve(&zc, &za)) == 0;
 318             zap_cursor_advance(&zc)) {
 319                 uint64_t intval = 0;
 320                 char *strval = NULL;
 321                 zprop_source_t src = ZPROP_SRC_DEFAULT;
 322                 zpool_prop_t prop;
 323 
 324                 if ((prop = zpool_name_to_prop(za.za_name)) == ZPROP_INVAL)
 325                         continue;
 326 
 327                 switch (za.za_integer_length) {
 328                 case 8:
 329                         /* integer property */
 330                         if (za.za_first_integer !=
 331                             zpool_prop_default_numeric(prop))
 332                                 src = ZPROP_SRC_LOCAL;
 333 
 334                         if (prop == ZPOOL_PROP_BOOTFS) {
 335                                 dsl_pool_t *dp;
 336                                 dsl_dataset_t *ds = NULL;
 337 
 338                                 dp = spa_get_dsl(spa);
 339                                 dsl_pool_config_enter(dp, FTAG);
 340                                 if (err = dsl_dataset_hold_obj(dp,
 341                                     za.za_first_integer, FTAG, &ds)) {
 342                                         dsl_pool_config_exit(dp, FTAG);
 343                                         break;
 344                                 }
 345 
 346                                 strval = kmem_alloc(
 347                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1,
 348                                     KM_SLEEP);
 349                                 dsl_dataset_name(ds, strval);
 350                                 dsl_dataset_rele(ds, FTAG);
 351                                 dsl_pool_config_exit(dp, FTAG);
 352                         } else {
 353                                 strval = NULL;
 354                                 intval = za.za_first_integer;
 355                         }
 356 
 357                         spa_prop_add_list(*nvp, prop, strval, intval, src);
 358 
 359                         if (strval != NULL)
 360                                 kmem_free(strval,
 361                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1);
 362 
 363                         break;
 364 
 365                 case 1:
 366                         /* string property */
 367                         strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
 368                         err = zap_lookup(mos, spa->spa_pool_props_object,
 369                             za.za_name, 1, za.za_num_integers, strval);
 370                         if (err) {
 371                                 kmem_free(strval, za.za_num_integers);
 372                                 break;
 373                         }
 374                         spa_prop_add_list(*nvp, prop, strval, 0, src);
 375                         kmem_free(strval, za.za_num_integers);
 376                         break;
 377 
 378                 default:
 379                         break;
 380                 }
 381         }
 382         zap_cursor_fini(&zc);
 383         mutex_exit(&spa->spa_props_lock);
 384 out:
 385         if (err && err != ENOENT) {
 386                 nvlist_free(*nvp);
 387                 *nvp = NULL;
 388                 return (err);
 389         }
 390 
 391         return (0);
 392 }
 393 
 394 /*
 395  * Validate the given pool properties nvlist and modify the list
 396  * for the property values to be set.
 397  */
 398 static int
 399 spa_prop_validate(spa_t *spa, nvlist_t *props)
 400 {
 401         nvpair_t *elem;
 402         int error = 0, reset_bootfs = 0;
 403         uint64_t objnum = 0;
 404         boolean_t has_feature = B_FALSE;
 405 
 406         elem = NULL;
 407         while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
 408                 uint64_t intval;
 409                 char *strval, *slash, *check, *fname;
 410                 const char *propname = nvpair_name(elem);
 411                 zpool_prop_t prop = zpool_name_to_prop(propname);
 412 
 413                 switch (prop) {
 414                 case ZPROP_INVAL:
 415                         if (!zpool_prop_feature(propname)) {
 416                                 error = SET_ERROR(EINVAL);
 417                                 break;
 418                         }
 419 
 420                         /*
 421                          * Sanitize the input.
 422                          */
 423                         if (nvpair_type(elem) != DATA_TYPE_UINT64) {
 424                                 error = SET_ERROR(EINVAL);
 425                                 break;
 426                         }
 427 
 428                         if (nvpair_value_uint64(elem, &intval) != 0) {
 429                                 error = SET_ERROR(EINVAL);
 430                                 break;
 431                         }
 432 
 433                         if (intval != 0) {
 434                                 error = SET_ERROR(EINVAL);
 435                                 break;
 436                         }
 437 
 438                         fname = strchr(propname, '@') + 1;
 439                         if (zfeature_lookup_name(fname, NULL) != 0) {
 440                                 error = SET_ERROR(EINVAL);
 441                                 break;
 442                         }
 443 
 444                         has_feature = B_TRUE;
 445                         break;
 446 
 447                 case ZPOOL_PROP_VERSION:
 448                         error = nvpair_value_uint64(elem, &intval);
 449                         if (!error &&
 450                             (intval < spa_version(spa) ||
 451                             intval > SPA_VERSION_BEFORE_FEATURES ||
 452                             has_feature))
 453                                 error = SET_ERROR(EINVAL);
 454                         break;
 455 
 456                 case ZPOOL_PROP_DELEGATION:
 457                 case ZPOOL_PROP_AUTOREPLACE:
 458                 case ZPOOL_PROP_LISTSNAPS:
 459                 case ZPOOL_PROP_AUTOEXPAND:
 460                         error = nvpair_value_uint64(elem, &intval);
 461                         if (!error && intval > 1)
 462                                 error = SET_ERROR(EINVAL);
 463                         break;
 464 
 465                 case ZPOOL_PROP_BOOTFS:
 466                         /*
 467                          * If the pool version is less than SPA_VERSION_BOOTFS,
 468                          * or the pool is still being created (version == 0),
 469                          * the bootfs property cannot be set.
 470                          */
 471                         if (spa_version(spa) < SPA_VERSION_BOOTFS) {
 472                                 error = SET_ERROR(ENOTSUP);
 473                                 break;
 474                         }
 475 
 476                         /*
 477                          * Make sure the vdev config is bootable
 478                          */
 479                         if (!vdev_is_bootable(spa->spa_root_vdev)) {
 480                                 error = SET_ERROR(ENOTSUP);
 481                                 break;
 482                         }
 483 
 484                         reset_bootfs = 1;
 485 
 486                         error = nvpair_value_string(elem, &strval);
 487 
 488                         if (!error) {
 489                                 objset_t *os;
 490                                 uint64_t compress;
 491 
 492                                 if (strval == NULL || strval[0] == '\0') {
 493                                         objnum = zpool_prop_default_numeric(
 494                                             ZPOOL_PROP_BOOTFS);
 495                                         break;
 496                                 }
 497 
 498                                 if (error = dmu_objset_hold(strval, FTAG, &os))
 499                                         break;
 500 
 501                                 /* Must be ZPL and not gzip compressed. */
 502 
 503                                 if (dmu_objset_type(os) != DMU_OST_ZFS) {
 504                                         error = SET_ERROR(ENOTSUP);
 505                                 } else if ((error =
 506                                     dsl_prop_get_int_ds(dmu_objset_ds(os),
 507                                     zfs_prop_to_name(ZFS_PROP_COMPRESSION),
 508                                     &compress)) == 0 &&
 509                                     !BOOTFS_COMPRESS_VALID(compress)) {
 510                                         error = SET_ERROR(ENOTSUP);
 511                                 } else {
 512                                         objnum = dmu_objset_id(os);
 513                                 }
 514                                 dmu_objset_rele(os, FTAG);
 515                         }
 516                         break;
 517 
 518                 case ZPOOL_PROP_FAILUREMODE:
 519                         error = nvpair_value_uint64(elem, &intval);
 520                         if (!error && (intval < ZIO_FAILURE_MODE_WAIT ||
 521                             intval > ZIO_FAILURE_MODE_PANIC))
 522                                 error = SET_ERROR(EINVAL);
 523 
 524                         /*
 525                          * This is a special case which only occurs when
 526                          * the pool has completely failed. This allows
 527                          * the user to change the in-core failmode property
 528                          * without syncing it out to disk (I/Os might
 529                          * currently be blocked). We do this by returning
 530                          * EIO to the caller (spa_prop_set) to trick it
 531                          * into thinking we encountered a property validation
 532                          * error.
 533                          */
 534                         if (!error && spa_suspended(spa)) {
 535                                 spa->spa_failmode = intval;
 536                                 error = SET_ERROR(EIO);
 537                         }
 538                         break;
 539 
 540                 case ZPOOL_PROP_CACHEFILE:
 541                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 542                                 break;
 543 
 544                         if (strval[0] == '\0')
 545                                 break;
 546 
 547                         if (strcmp(strval, "none") == 0)
 548                                 break;
 549 
 550                         if (strval[0] != '/') {
 551                                 error = SET_ERROR(EINVAL);
 552                                 break;
 553                         }
 554 
 555                         slash = strrchr(strval, '/');
 556                         ASSERT(slash != NULL);
 557 
 558                         if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
 559                             strcmp(slash, "/..") == 0)
 560                                 error = SET_ERROR(EINVAL);
 561                         break;
 562 
 563                 case ZPOOL_PROP_COMMENT:
 564                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 565                                 break;
 566                         for (check = strval; *check != '\0'; check++) {
 567                                 /*
 568                                  * The kernel doesn't have an easy isprint()
 569                                  * check.  For this kernel check, we merely
 570                                  * check ASCII apart from DEL.  Fix this if
 571                                  * there is an easy-to-use kernel isprint().
 572                                  */
 573                                 if (*check >= 0x7f) {
 574                                         error = SET_ERROR(EINVAL);
 575                                         break;
 576                                 }
 577                                 check++;
 578                         }
 579                         if (strlen(strval) > ZPROP_MAX_COMMENT)
 580                                 error = E2BIG;
 581                         break;
 582 
 583                 case ZPOOL_PROP_DEDUPDITTO:
 584                         if (spa_version(spa) < SPA_VERSION_DEDUP)
 585                                 error = SET_ERROR(ENOTSUP);
 586                         else
 587                                 error = nvpair_value_uint64(elem, &intval);
 588                         if (error == 0 &&
 589                             intval != 0 && intval < ZIO_DEDUPDITTO_MIN)
 590                                 error = SET_ERROR(EINVAL);
 591                         break;
 592                 }
 593 
 594                 if (error)
 595                         break;
 596         }
 597 
 598         if (!error && reset_bootfs) {
 599                 error = nvlist_remove(props,
 600                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
 601 
 602                 if (!error) {
 603                         error = nvlist_add_uint64(props,
 604                             zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
 605                 }
 606         }
 607 
 608         return (error);
 609 }
 610 
 611 void
 612 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
 613 {
 614         char *cachefile;
 615         spa_config_dirent_t *dp;
 616 
 617         if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
 618             &cachefile) != 0)
 619                 return;
 620 
 621         dp = kmem_alloc(sizeof (spa_config_dirent_t),
 622             KM_SLEEP);
 623 
 624         if (cachefile[0] == '\0')
 625                 dp->scd_path = spa_strdup(spa_config_path);
 626         else if (strcmp(cachefile, "none") == 0)
 627                 dp->scd_path = NULL;
 628         else
 629                 dp->scd_path = spa_strdup(cachefile);
 630 
 631         list_insert_head(&spa->spa_config_list, dp);
 632         if (need_sync)
 633                 spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
 634 }
 635 
 636 int
 637 spa_prop_set(spa_t *spa, nvlist_t *nvp)
 638 {
 639         int error;
 640         nvpair_t *elem = NULL;
 641         boolean_t need_sync = B_FALSE;
 642 
 643         if ((error = spa_prop_validate(spa, nvp)) != 0)
 644                 return (error);
 645 
 646         while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
 647                 zpool_prop_t prop = zpool_name_to_prop(nvpair_name(elem));
 648 
 649                 if (prop == ZPOOL_PROP_CACHEFILE ||
 650                     prop == ZPOOL_PROP_ALTROOT ||
 651                     prop == ZPOOL_PROP_READONLY)
 652                         continue;
 653 
 654                 if (prop == ZPOOL_PROP_VERSION || prop == ZPROP_INVAL) {
 655                         uint64_t ver;
 656 
 657                         if (prop == ZPOOL_PROP_VERSION) {
 658                                 VERIFY(nvpair_value_uint64(elem, &ver) == 0);
 659                         } else {
 660                                 ASSERT(zpool_prop_feature(nvpair_name(elem)));
 661                                 ver = SPA_VERSION_FEATURES;
 662                                 need_sync = B_TRUE;
 663                         }
 664 
 665                         /* Save time if the version is already set. */
 666                         if (ver == spa_version(spa))
 667                                 continue;
 668 
 669                         /*
 670                          * In addition to the pool directory object, we might
 671                          * create the pool properties object, the features for
 672                          * read object, the features for write object, or the
 673                          * feature descriptions object.
 674                          */
 675                         error = dsl_sync_task(spa->spa_name, NULL,
 676                             spa_sync_version, &ver,
 677                             6, ZFS_SPACE_CHECK_RESERVED);
 678                         if (error)
 679                                 return (error);
 680                         continue;
 681                 }
 682 
 683                 need_sync = B_TRUE;
 684                 break;
 685         }
 686 
 687         if (need_sync) {
 688                 return (dsl_sync_task(spa->spa_name, NULL, spa_sync_props,
 689                     nvp, 6, ZFS_SPACE_CHECK_RESERVED));
 690         }
 691 
 692         return (0);
 693 }
 694 
 695 /*
 696  * If the bootfs property value is dsobj, clear it.
 697  */
 698 void
 699 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
 700 {
 701         if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
 702                 VERIFY(zap_remove(spa->spa_meta_objset,
 703                     spa->spa_pool_props_object,
 704                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
 705                 spa->spa_bootfs = 0;
 706         }
 707 }
 708 
 709 /*ARGSUSED*/
 710 static int
 711 spa_change_guid_check(void *arg, dmu_tx_t *tx)
 712 {
 713         uint64_t *newguid = arg;
 714         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 715         vdev_t *rvd = spa->spa_root_vdev;
 716         uint64_t vdev_state;
 717 
 718         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
 719         vdev_state = rvd->vdev_state;
 720         spa_config_exit(spa, SCL_STATE, FTAG);
 721 
 722         if (vdev_state != VDEV_STATE_HEALTHY)
 723                 return (SET_ERROR(ENXIO));
 724 
 725         ASSERT3U(spa_guid(spa), !=, *newguid);
 726 
 727         return (0);
 728 }
 729 
 730 static void
 731 spa_change_guid_sync(void *arg, dmu_tx_t *tx)
 732 {
 733         uint64_t *newguid = arg;
 734         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 735         uint64_t oldguid;
 736         vdev_t *rvd = spa->spa_root_vdev;
 737 
 738         oldguid = spa_guid(spa);
 739 
 740         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
 741         rvd->vdev_guid = *newguid;
 742         rvd->vdev_guid_sum += (*newguid - oldguid);
 743         vdev_config_dirty(rvd);
 744         spa_config_exit(spa, SCL_STATE, FTAG);
 745 
 746         spa_history_log_internal(spa, "guid change", tx, "old=%llu new=%llu",
 747             oldguid, *newguid);
 748 }
 749 
 750 /*
 751  * Change the GUID for the pool.  This is done so that we can later
 752  * re-import a pool built from a clone of our own vdevs.  We will modify
 753  * the root vdev's guid, our own pool guid, and then mark all of our
 754  * vdevs dirty.  Note that we must make sure that all our vdevs are
 755  * online when we do this, or else any vdevs that weren't present
 756  * would be orphaned from our pool.  We are also going to issue a
 757  * sysevent to update any watchers.
 758  */
 759 int
 760 spa_change_guid(spa_t *spa)
 761 {
 762         int error;
 763         uint64_t guid;
 764 
 765         mutex_enter(&spa->spa_vdev_top_lock);
 766         mutex_enter(&spa_namespace_lock);
 767         guid = spa_generate_guid(NULL);
 768 
 769         error = dsl_sync_task(spa->spa_name, spa_change_guid_check,
 770             spa_change_guid_sync, &guid, 5, ZFS_SPACE_CHECK_RESERVED);
 771 
 772         if (error == 0) {
 773                 spa_config_sync(spa, B_FALSE, B_TRUE);
 774                 spa_event_notify(spa, NULL, ESC_ZFS_POOL_REGUID);
 775         }
 776 
 777         mutex_exit(&spa_namespace_lock);
 778         mutex_exit(&spa->spa_vdev_top_lock);
 779 
 780         return (error);
 781 }
 782 
 783 /*
 784  * ==========================================================================
 785  * SPA state manipulation (open/create/destroy/import/export)
 786  * ==========================================================================
 787  */
 788 
 789 static int
 790 spa_error_entry_compare(const void *a, const void *b)
 791 {
 792         spa_error_entry_t *sa = (spa_error_entry_t *)a;
 793         spa_error_entry_t *sb = (spa_error_entry_t *)b;
 794         int ret;
 795 
 796         ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
 797             sizeof (zbookmark_phys_t));
 798 
 799         if (ret < 0)
 800                 return (-1);
 801         else if (ret > 0)
 802                 return (1);
 803         else
 804                 return (0);
 805 }
 806 
 807 /*
 808  * Utility function which retrieves copies of the current logs and
 809  * re-initializes them in the process.
 810  */
 811 void
 812 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
 813 {
 814         ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
 815 
 816         bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
 817         bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));
 818 
 819         avl_create(&spa->spa_errlist_scrub,
 820             spa_error_entry_compare, sizeof (spa_error_entry_t),
 821             offsetof(spa_error_entry_t, se_avl));
 822         avl_create(&spa->spa_errlist_last,
 823             spa_error_entry_compare, sizeof (spa_error_entry_t),
 824             offsetof(spa_error_entry_t, se_avl));
 825 }
 826 
 827 static void
 828 spa_taskqs_init(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
 829 {
 830         const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
 831         enum zti_modes mode = ztip->zti_mode;
 832         uint_t value = ztip->zti_value;
 833         uint_t count = ztip->zti_count;
 834         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 835         char name[32];
 836         uint_t flags = 0;
 837         boolean_t batch = B_FALSE;
 838 
 839         if (mode == ZTI_MODE_NULL) {
 840                 tqs->stqs_count = 0;
 841                 tqs->stqs_taskq = NULL;
 842                 return;
 843         }
 844 
 845         ASSERT3U(count, >, 0);
 846 
 847         tqs->stqs_count = count;
 848         tqs->stqs_taskq = kmem_alloc(count * sizeof (taskq_t *), KM_SLEEP);
 849 
 850         switch (mode) {
 851         case ZTI_MODE_FIXED:
 852                 ASSERT3U(value, >=, 1);
 853                 value = MAX(value, 1);
 854                 break;
 855 
 856         case ZTI_MODE_BATCH:
 857                 batch = B_TRUE;
 858                 flags |= TASKQ_THREADS_CPU_PCT;
 859                 value = zio_taskq_batch_pct;
 860                 break;
 861 
 862         default:
 863                 panic("unrecognized mode for %s_%s taskq (%u:%u) in "
 864                     "spa_activate()",
 865                     zio_type_name[t], zio_taskq_types[q], mode, value);
 866                 break;
 867         }
 868 
 869         for (uint_t i = 0; i < count; i++) {
 870                 taskq_t *tq;
 871 
 872                 if (count > 1) {
 873                         (void) snprintf(name, sizeof (name), "%s_%s_%u",
 874                             zio_type_name[t], zio_taskq_types[q], i);
 875                 } else {
 876                         (void) snprintf(name, sizeof (name), "%s_%s",
 877                             zio_type_name[t], zio_taskq_types[q]);
 878                 }
 879 
 880                 if (zio_taskq_sysdc && spa->spa_proc != &p0) {
 881                         if (batch)
 882                                 flags |= TASKQ_DC_BATCH;
 883 
 884                         tq = taskq_create_sysdc(name, value, 50, INT_MAX,
 885                             spa->spa_proc, zio_taskq_basedc, flags);
 886                 } else {
 887                         pri_t pri = maxclsyspri;
 888                         /*
 889                          * The write issue taskq can be extremely CPU
 890                          * intensive.  Run it at slightly lower priority
 891                          * than the other taskqs.
 892                          */
 893                         if (t == ZIO_TYPE_WRITE && q == ZIO_TASKQ_ISSUE)
 894                                 pri--;
 895 
 896                         tq = taskq_create_proc(name, value, pri, 50,
 897                             INT_MAX, spa->spa_proc, flags);
 898                 }
 899 
 900                 tqs->stqs_taskq[i] = tq;
 901         }
 902 }
 903 
 904 static void
 905 spa_taskqs_fini(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
 906 {
 907         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 908 
 909         if (tqs->stqs_taskq == NULL) {
 910                 ASSERT0(tqs->stqs_count);
 911                 return;
 912         }
 913 
 914         for (uint_t i = 0; i < tqs->stqs_count; i++) {
 915                 ASSERT3P(tqs->stqs_taskq[i], !=, NULL);
 916                 taskq_destroy(tqs->stqs_taskq[i]);
 917         }
 918 
 919         kmem_free(tqs->stqs_taskq, tqs->stqs_count * sizeof (taskq_t *));
 920         tqs->stqs_taskq = NULL;
 921 }
 922 
 923 /*
 924  * Dispatch a task to the appropriate taskq for the ZFS I/O type and priority.
 925  * Note that a type may have multiple discrete taskqs to avoid lock contention
 926  * on the taskq itself. In that case we choose which taskq at random by using
 927  * the low bits of gethrtime().
 928  */
 929 void
 930 spa_taskq_dispatch_ent(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
 931     task_func_t *func, void *arg, uint_t flags, taskq_ent_t *ent)
 932 {
 933         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 934         taskq_t *tq;
 935 
 936         ASSERT3P(tqs->stqs_taskq, !=, NULL);
 937         ASSERT3U(tqs->stqs_count, !=, 0);
 938 
 939         if (tqs->stqs_count == 1) {
 940                 tq = tqs->stqs_taskq[0];
 941         } else {
 942                 tq = tqs->stqs_taskq[gethrtime() % tqs->stqs_count];
 943         }
 944 
 945         taskq_dispatch_ent(tq, func, arg, flags, ent);
 946 }
 947 
 948 static void
 949 spa_create_zio_taskqs(spa_t *spa)
 950 {
 951         for (int t = 0; t < ZIO_TYPES; t++) {
 952                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
 953                         spa_taskqs_init(spa, t, q);
 954                 }
 955         }
 956 }
 957 
 958 #ifdef _KERNEL
 959 static void
 960 spa_thread(void *arg)
 961 {
 962         callb_cpr_t cprinfo;
 963 
 964         spa_t *spa = arg;
 965         user_t *pu = PTOU(curproc);
 966 
 967         CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
 968             spa->spa_name);
 969 
 970         ASSERT(curproc != &p0);
 971         (void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
 972             "zpool-%s", spa->spa_name);
 973         (void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
 974 
 975         /* bind this thread to the requested psrset */
 976         if (zio_taskq_psrset_bind != PS_NONE) {
 977                 pool_lock();
 978                 mutex_enter(&cpu_lock);
 979                 mutex_enter(&pidlock);
 980                 mutex_enter(&curproc->p_lock);
 981 
 982                 if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
 983                     0, NULL, NULL) == 0)  {
 984                         curthread->t_bind_pset = zio_taskq_psrset_bind;
 985                 } else {
 986                         cmn_err(CE_WARN,
 987                             "Couldn't bind process for zfs pool \"%s\" to "
 988                             "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
 989                 }
 990 
 991                 mutex_exit(&curproc->p_lock);
 992                 mutex_exit(&pidlock);
 993                 mutex_exit(&cpu_lock);
 994                 pool_unlock();
 995         }
 996 
 997         if (zio_taskq_sysdc) {
 998                 sysdc_thread_enter(curthread, 100, 0);
 999         }
1000 
1001         spa->spa_proc = curproc;
1002         spa->spa_did = curthread->t_did;
1003 
1004         spa_create_zio_taskqs(spa);
1005 
1006         mutex_enter(&spa->spa_proc_lock);
1007         ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
1008 
1009         spa->spa_proc_state = SPA_PROC_ACTIVE;
1010         cv_broadcast(&spa->spa_proc_cv);
1011 
1012         CALLB_CPR_SAFE_BEGIN(&cprinfo);
1013         while (spa->spa_proc_state == SPA_PROC_ACTIVE)
1014                 cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1015         CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
1016 
1017         ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
1018         spa->spa_proc_state = SPA_PROC_GONE;
1019         spa->spa_proc = &p0;
1020         cv_broadcast(&spa->spa_proc_cv);
1021         CALLB_CPR_EXIT(&cprinfo);   /* drops spa_proc_lock */
1022 
1023         mutex_enter(&curproc->p_lock);
1024         lwp_exit();
1025 }
1026 #endif
1027 
1028 /*
1029  * Activate an uninitialized pool.
1030  */
1031 static void
1032 spa_activate(spa_t *spa, int mode)
1033 {
1034         ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
1035 
1036         spa->spa_state = POOL_STATE_ACTIVE;
1037         spa->spa_mode = mode;
1038 
1039         spa->spa_normal_class = metaslab_class_create(spa, zfs_metaslab_ops);
1040         spa->spa_log_class = metaslab_class_create(spa, zfs_metaslab_ops);
1041 
1042         /* Try to create a covering process */
1043         mutex_enter(&spa->spa_proc_lock);
1044         ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
1045         ASSERT(spa->spa_proc == &p0);
1046         spa->spa_did = 0;
1047 
1048         /* Only create a process if we're going to be around a while. */
1049         if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
1050                 if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
1051                     NULL, 0) == 0) {
1052                         spa->spa_proc_state = SPA_PROC_CREATED;
1053                         while (spa->spa_proc_state == SPA_PROC_CREATED) {
1054                                 cv_wait(&spa->spa_proc_cv,
1055                                     &spa->spa_proc_lock);
1056                         }
1057                         ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1058                         ASSERT(spa->spa_proc != &p0);
1059                         ASSERT(spa->spa_did != 0);
1060                 } else {
1061 #ifdef _KERNEL
1062                         cmn_err(CE_WARN,
1063                             "Couldn't create process for zfs pool \"%s\"\n",
1064                             spa->spa_name);
1065 #endif
1066                 }
1067         }
1068         mutex_exit(&spa->spa_proc_lock);
1069 
1070         /* If we didn't create a process, we need to create our taskqs. */
1071         if (spa->spa_proc == &p0) {
1072                 spa_create_zio_taskqs(spa);
1073         }
1074 
1075         list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
1076             offsetof(vdev_t, vdev_config_dirty_node));
1077         list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
1078             offsetof(vdev_t, vdev_state_dirty_node));
1079 
1080         txg_list_create(&spa->spa_vdev_txg_list,
1081             offsetof(struct vdev, vdev_txg_node));
1082 
1083         avl_create(&spa->spa_errlist_scrub,
1084             spa_error_entry_compare, sizeof (spa_error_entry_t),
1085             offsetof(spa_error_entry_t, se_avl));
1086         avl_create(&spa->spa_errlist_last,
1087             spa_error_entry_compare, sizeof (spa_error_entry_t),
1088             offsetof(spa_error_entry_t, se_avl));
1089 }
1090 
1091 /*
1092  * Opposite of spa_activate().
1093  */
1094 static void
1095 spa_deactivate(spa_t *spa)
1096 {
1097         ASSERT(spa->spa_sync_on == B_FALSE);
1098         ASSERT(spa->spa_dsl_pool == NULL);
1099         ASSERT(spa->spa_root_vdev == NULL);
1100         ASSERT(spa->spa_async_zio_root == NULL);
1101         ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
1102 
1103         txg_list_destroy(&spa->spa_vdev_txg_list);
1104 
1105         list_destroy(&spa->spa_config_dirty_list);
1106         list_destroy(&spa->spa_state_dirty_list);
1107 
1108         for (int t = 0; t < ZIO_TYPES; t++) {
1109                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
1110                         spa_taskqs_fini(spa, t, q);
1111                 }
1112         }
1113 
1114         metaslab_class_destroy(spa->spa_normal_class);
1115         spa->spa_normal_class = NULL;
1116 
1117         metaslab_class_destroy(spa->spa_log_class);
1118         spa->spa_log_class = NULL;
1119 
1120         /*
1121          * If this was part of an import or the open otherwise failed, we may
1122          * still have errors left in the queues.  Empty them just in case.
1123          */
1124         spa_errlog_drain(spa);
1125 
1126         avl_destroy(&spa->spa_errlist_scrub);
1127         avl_destroy(&spa->spa_errlist_last);
1128 
1129         spa->spa_state = POOL_STATE_UNINITIALIZED;
1130 
1131         mutex_enter(&spa->spa_proc_lock);
1132         if (spa->spa_proc_state != SPA_PROC_NONE) {
1133                 ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1134                 spa->spa_proc_state = SPA_PROC_DEACTIVATE;
1135                 cv_broadcast(&spa->spa_proc_cv);
1136                 while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
1137                         ASSERT(spa->spa_proc != &p0);
1138                         cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1139                 }
1140                 ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
1141                 spa->spa_proc_state = SPA_PROC_NONE;
1142         }
1143         ASSERT(spa->spa_proc == &p0);
1144         mutex_exit(&spa->spa_proc_lock);
1145 
1146         /*
1147          * We want to make sure spa_thread() has actually exited the ZFS
1148          * module, so that the module can't be unloaded out from underneath
1149          * it.
1150          */
1151         if (spa->spa_did != 0) {
1152                 thread_join(spa->spa_did);
1153                 spa->spa_did = 0;
1154         }
1155 }
1156 
1157 /*
1158  * Verify a pool configuration, and construct the vdev tree appropriately.  This
1159  * will create all the necessary vdevs in the appropriate layout, with each vdev
1160  * in the CLOSED state.  This will prep the pool before open/creation/import.
1161  * All vdev validation is done by the vdev_alloc() routine.
1162  */
1163 static int
1164 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
1165     uint_t id, int atype)
1166 {
1167         nvlist_t **child;
1168         uint_t children;
1169         int error;
1170 
1171         if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
1172                 return (error);
1173 
1174         if ((*vdp)->vdev_ops->vdev_op_leaf)
1175                 return (0);
1176 
1177         error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
1178             &child, &children);
1179 
1180         if (error == ENOENT)
1181                 return (0);
1182 
1183         if (error) {
1184                 vdev_free(*vdp);
1185                 *vdp = NULL;
1186                 return (SET_ERROR(EINVAL));
1187         }
1188 
1189         for (int c = 0; c < children; c++) {
1190                 vdev_t *vd;
1191                 if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
1192                     atype)) != 0) {
1193                         vdev_free(*vdp);
1194                         *vdp = NULL;
1195                         return (error);
1196                 }
1197         }
1198 
1199         ASSERT(*vdp != NULL);
1200 
1201         return (0);
1202 }
1203 
1204 /*
1205  * Opposite of spa_load().
1206  */
1207 static void
1208 spa_unload(spa_t *spa)
1209 {
1210         int i;
1211 
1212         ASSERT(MUTEX_HELD(&spa_namespace_lock));
1213 
1214         /*
1215          * Stop async tasks.
1216          */
1217         spa_async_suspend(spa);
1218 
1219         /*
1220          * Stop syncing.
1221          */
1222         if (spa->spa_sync_on) {
1223                 txg_sync_stop(spa->spa_dsl_pool);
1224                 spa->spa_sync_on = B_FALSE;
1225         }
1226 
1227         /*
1228          * Wait for any outstanding async I/O to complete.
1229          */
1230         if (spa->spa_async_zio_root != NULL) {
1231                 (void) zio_wait(spa->spa_async_zio_root);
1232                 spa->spa_async_zio_root = NULL;
1233         }
1234 
1235         bpobj_close(&spa->spa_deferred_bpobj);
1236 
1237         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1238 
1239         /*
1240          * Close all vdevs.
1241          */
1242         if (spa->spa_root_vdev)
1243                 vdev_free(spa->spa_root_vdev);
1244         ASSERT(spa->spa_root_vdev == NULL);
1245 
1246         /*
1247          * Close the dsl pool.
1248          */
1249         if (spa->spa_dsl_pool) {
1250                 dsl_pool_close(spa->spa_dsl_pool);
1251                 spa->spa_dsl_pool = NULL;
1252                 spa->spa_meta_objset = NULL;
1253         }
1254 
1255         ddt_unload(spa);
1256 
1257 
1258         /*
1259          * Drop and purge level 2 cache
1260          */
1261         spa_l2cache_drop(spa);
1262 
1263         for (i = 0; i < spa->spa_spares.sav_count; i++)
1264                 vdev_free(spa->spa_spares.sav_vdevs[i]);
1265         if (spa->spa_spares.sav_vdevs) {
1266                 kmem_free(spa->spa_spares.sav_vdevs,
1267                     spa->spa_spares.sav_count * sizeof (void *));
1268                 spa->spa_spares.sav_vdevs = NULL;
1269         }
1270         if (spa->spa_spares.sav_config) {
1271                 nvlist_free(spa->spa_spares.sav_config);
1272                 spa->spa_spares.sav_config = NULL;
1273         }
1274         spa->spa_spares.sav_count = 0;
1275 
1276         for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
1277                 vdev_clear_stats(spa->spa_l2cache.sav_vdevs[i]);
1278                 vdev_free(spa->spa_l2cache.sav_vdevs[i]);
1279         }
1280         if (spa->spa_l2cache.sav_vdevs) {
1281                 kmem_free(spa->spa_l2cache.sav_vdevs,
1282                     spa->spa_l2cache.sav_count * sizeof (void *));
1283                 spa->spa_l2cache.sav_vdevs = NULL;
1284         }
1285         if (spa->spa_l2cache.sav_config) {
1286                 nvlist_free(spa->spa_l2cache.sav_config);
1287                 spa->spa_l2cache.sav_config = NULL;
1288         }
1289         spa->spa_l2cache.sav_count = 0;
1290 
1291         spa->spa_async_suspended = 0;
1292 
1293         if (spa->spa_comment != NULL) {
1294                 spa_strfree(spa->spa_comment);
1295                 spa->spa_comment = NULL;
1296         }
1297 
1298         spa_config_exit(spa, SCL_ALL, FTAG);
1299 }
1300 
1301 /*
1302  * Load (or re-load) the current list of vdevs describing the active spares for
1303  * this pool.  When this is called, we have some form of basic information in
1304  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
1305  * then re-generate a more complete list including status information.
1306  */
1307 static void
1308 spa_load_spares(spa_t *spa)
1309 {
1310         nvlist_t **spares;
1311         uint_t nspares;
1312         int i;
1313         vdev_t *vd, *tvd;
1314 
1315         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1316 
1317         /*
1318          * First, close and free any existing spare vdevs.
1319          */
1320         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1321                 vd = spa->spa_spares.sav_vdevs[i];
1322 
1323                 /* Undo the call to spa_activate() below */
1324                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1325                     B_FALSE)) != NULL && tvd->vdev_isspare)
1326                         spa_spare_remove(tvd);
1327                 vdev_close(vd);
1328                 vdev_free(vd);
1329         }
1330 
1331         if (spa->spa_spares.sav_vdevs)
1332                 kmem_free(spa->spa_spares.sav_vdevs,
1333                     spa->spa_spares.sav_count * sizeof (void *));
1334 
1335         if (spa->spa_spares.sav_config == NULL)
1336                 nspares = 0;
1337         else
1338                 VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1339                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1340 
1341         spa->spa_spares.sav_count = (int)nspares;
1342         spa->spa_spares.sav_vdevs = NULL;
1343 
1344         if (nspares == 0)
1345                 return;
1346 
1347         /*
1348          * Construct the array of vdevs, opening them to get status in the
1349          * process.   For each spare, there is potentially two different vdev_t
1350          * structures associated with it: one in the list of spares (used only
1351          * for basic validation purposes) and one in the active vdev
1352          * configuration (if it's spared in).  During this phase we open and
1353          * validate each vdev on the spare list.  If the vdev also exists in the
1354          * active configuration, then we also mark this vdev as an active spare.
1355          */
1356         spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
1357             KM_SLEEP);
1358         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1359                 VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
1360                     VDEV_ALLOC_SPARE) == 0);
1361                 ASSERT(vd != NULL);
1362 
1363                 spa->spa_spares.sav_vdevs[i] = vd;
1364 
1365                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1366                     B_FALSE)) != NULL) {
1367                         if (!tvd->vdev_isspare)
1368                                 spa_spare_add(tvd);
1369 
1370                         /*
1371                          * We only mark the spare active if we were successfully
1372                          * able to load the vdev.  Otherwise, importing a pool
1373                          * with a bad active spare would result in strange
1374                          * behavior, because multiple pool would think the spare
1375                          * is actively in use.
1376                          *
1377                          * There is a vulnerability here to an equally bizarre
1378                          * circumstance, where a dead active spare is later
1379                          * brought back to life (onlined or otherwise).  Given
1380                          * the rarity of this scenario, and the extra complexity
1381                          * it adds, we ignore the possibility.
1382                          */
1383                         if (!vdev_is_dead(tvd))
1384                                 spa_spare_activate(tvd);
1385                 }
1386 
1387                 vd->vdev_top = vd;
1388                 vd->vdev_aux = &spa->spa_spares;
1389 
1390                 if (vdev_open(vd) != 0)
1391                         continue;
1392 
1393                 if (vdev_validate_aux(vd) == 0)
1394                         spa_spare_add(vd);
1395         }
1396 
1397         /*
1398          * Recompute the stashed list of spares, with status information
1399          * this time.
1400          */
1401         VERIFY(nvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES,
1402             DATA_TYPE_NVLIST_ARRAY) == 0);
1403 
1404         spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
1405             KM_SLEEP);
1406         for (i = 0; i < spa->spa_spares.sav_count; i++)
1407                 spares[i] = vdev_config_generate(spa,
1408                     spa->spa_spares.sav_vdevs[i], B_TRUE, VDEV_CONFIG_SPARE);
1409         VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
1410             ZPOOL_CONFIG_SPARES, spares, spa->spa_spares.sav_count) == 0);
1411         for (i = 0; i < spa->spa_spares.sav_count; i++)
1412                 nvlist_free(spares[i]);
1413         kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
1414 }
1415 
1416 /*
1417  * Load (or re-load) the current list of vdevs describing the active l2cache for
1418  * this pool.  When this is called, we have some form of basic information in
1419  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
1420  * then re-generate a more complete list including status information.
1421  * Devices which are already active have their details maintained, and are
1422  * not re-opened.
1423  */
1424 static void
1425 spa_load_l2cache(spa_t *spa)
1426 {
1427         nvlist_t **l2cache;
1428         uint_t nl2cache;
1429         int i, j, oldnvdevs;
1430         uint64_t guid;
1431         vdev_t *vd, **oldvdevs, **newvdevs;
1432         spa_aux_vdev_t *sav = &spa->spa_l2cache;
1433 
1434         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1435 
1436         if (sav->sav_config != NULL) {
1437                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
1438                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1439                 newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
1440         } else {
1441                 nl2cache = 0;
1442                 newvdevs = NULL;
1443         }
1444 
1445         oldvdevs = sav->sav_vdevs;
1446         oldnvdevs = sav->sav_count;
1447         sav->sav_vdevs = NULL;
1448         sav->sav_count = 0;
1449 
1450         /*
1451          * Process new nvlist of vdevs.
1452          */
1453         for (i = 0; i < nl2cache; i++) {
1454                 VERIFY(nvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID,
1455                     &guid) == 0);
1456 
1457                 newvdevs[i] = NULL;
1458                 for (j = 0; j < oldnvdevs; j++) {
1459                         vd = oldvdevs[j];
1460                         if (vd != NULL && guid == vd->vdev_guid) {
1461                                 /*
1462                                  * Retain previous vdev for add/remove ops.
1463                                  */
1464                                 newvdevs[i] = vd;
1465                                 oldvdevs[j] = NULL;
1466                                 break;
1467                         }
1468                 }
1469 
1470                 if (newvdevs[i] == NULL) {
1471                         /*
1472                          * Create new vdev
1473                          */
1474                         VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
1475                             VDEV_ALLOC_L2CACHE) == 0);
1476                         ASSERT(vd != NULL);
1477                         newvdevs[i] = vd;
1478 
1479                         /*
1480                          * Commit this vdev as an l2cache device,
1481                          * even if it fails to open.
1482                          */
1483                         spa_l2cache_add(vd);
1484 
1485                         vd->vdev_top = vd;
1486                         vd->vdev_aux = sav;
1487 
1488                         spa_l2cache_activate(vd);
1489 
1490                         if (vdev_open(vd) != 0)
1491                                 continue;
1492 
1493                         (void) vdev_validate_aux(vd);
1494 
1495                         if (!vdev_is_dead(vd))
1496                                 l2arc_add_vdev(spa, vd);
1497                 }
1498         }
1499 
1500         /*
1501          * Purge vdevs that were dropped
1502          */
1503         for (i = 0; i < oldnvdevs; i++) {
1504                 uint64_t pool;
1505 
1506                 vd = oldvdevs[i];
1507                 if (vd != NULL) {
1508                         ASSERT(vd->vdev_isl2cache);
1509 
1510                         if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
1511                             pool != 0ULL && l2arc_vdev_present(vd))
1512                                 l2arc_remove_vdev(vd);
1513                         vdev_clear_stats(vd);
1514                         vdev_free(vd);
1515                 }
1516         }
1517 
1518         if (oldvdevs)
1519                 kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
1520 
1521         if (sav->sav_config == NULL)
1522                 goto out;
1523 
1524         sav->sav_vdevs = newvdevs;
1525         sav->sav_count = (int)nl2cache;
1526 
1527         /*
1528          * Recompute the stashed list of l2cache devices, with status
1529          * information this time.
1530          */
1531         VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
1532             DATA_TYPE_NVLIST_ARRAY) == 0);
1533 
1534         l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
1535         for (i = 0; i < sav->sav_count; i++)
1536                 l2cache[i] = vdev_config_generate(spa,
1537                     sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);
1538         VERIFY(nvlist_add_nvlist_array(sav->sav_config,
1539             ZPOOL_CONFIG_L2CACHE, l2cache, sav->sav_count) == 0);
1540 out:
1541         for (i = 0; i < sav->sav_count; i++)
1542                 nvlist_free(l2cache[i]);
1543         if (sav->sav_count)
1544                 kmem_free(l2cache, sav->sav_count * sizeof (void *));
1545 }
1546 
1547 static int
1548 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
1549 {
1550         dmu_buf_t *db;
1551         char *packed = NULL;
1552         size_t nvsize = 0;
1553         int error;
1554         *value = NULL;
1555 
1556         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
1557         nvsize = *(uint64_t *)db->db_data;
1558         dmu_buf_rele(db, FTAG);
1559 
1560         packed = kmem_alloc(nvsize, KM_SLEEP);
1561         error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
1562             DMU_READ_PREFETCH);
1563         if (error == 0)
1564                 error = nvlist_unpack(packed, nvsize, value, 0);
1565         kmem_free(packed, nvsize);
1566 
1567         return (error);
1568 }
1569 
1570 /*
1571  * Checks to see if the given vdev could not be opened, in which case we post a
1572  * sysevent to notify the autoreplace code that the device has been removed.
1573  */
1574 static void
1575 spa_check_removed(vdev_t *vd)
1576 {
1577         for (int c = 0; c < vd->vdev_children; c++)
1578                 spa_check_removed(vd->vdev_child[c]);
1579 
1580         if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd) &&
1581             !vd->vdev_ishole) {
1582                 zfs_post_autoreplace(vd->vdev_spa, vd);
1583                 spa_event_notify(vd->vdev_spa, vd, ESC_ZFS_VDEV_CHECK);
1584         }
1585 }
1586 
1587 /*
1588  * Validate the current config against the MOS config
1589  */
1590 static boolean_t
1591 spa_config_valid(spa_t *spa, nvlist_t *config)
1592 {
1593         vdev_t *mrvd, *rvd = spa->spa_root_vdev;
1594         nvlist_t *nv;
1595 
1596         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nv) == 0);
1597 
1598         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1599         VERIFY(spa_config_parse(spa, &mrvd, nv, NULL, 0, VDEV_ALLOC_LOAD) == 0);
1600 
1601         ASSERT3U(rvd->vdev_children, ==, mrvd->vdev_children);
1602 
1603         /*
1604          * If we're doing a normal import, then build up any additional
1605          * diagnostic information about missing devices in this config.
1606          * We'll pass this up to the user for further processing.
1607          */
1608         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG)) {
1609                 nvlist_t **child, *nv;
1610                 uint64_t idx = 0;
1611 
1612                 child = kmem_alloc(rvd->vdev_children * sizeof (nvlist_t **),
1613                     KM_SLEEP);
1614                 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1615 
1616                 for (int c = 0; c < rvd->vdev_children; c++) {
1617                         vdev_t *tvd = rvd->vdev_child[c];
1618                         vdev_t *mtvd  = mrvd->vdev_child[c];
1619 
1620                         if (tvd->vdev_ops == &vdev_missing_ops &&
1621                             mtvd->vdev_ops != &vdev_missing_ops &&
1622                             mtvd->vdev_islog)
1623                                 child[idx++] = vdev_config_generate(spa, mtvd,
1624                                     B_FALSE, 0);
1625                 }
1626 
1627                 if (idx) {
1628                         VERIFY(nvlist_add_nvlist_array(nv,
1629                             ZPOOL_CONFIG_CHILDREN, child, idx) == 0);
1630                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
1631                             ZPOOL_CONFIG_MISSING_DEVICES, nv) == 0);
1632 
1633                         for (int i = 0; i < idx; i++)
1634                                 nvlist_free(child[i]);
1635                 }
1636                 nvlist_free(nv);
1637                 kmem_free(child, rvd->vdev_children * sizeof (char **));
1638         }
1639 
1640         /*
1641          * Compare the root vdev tree with the information we have
1642          * from the MOS config (mrvd). Check each top-level vdev
1643          * with the corresponding MOS config top-level (mtvd).
1644          */
1645         for (int c = 0; c < rvd->vdev_children; c++) {
1646                 vdev_t *tvd = rvd->vdev_child[c];
1647                 vdev_t *mtvd  = mrvd->vdev_child[c];
1648 
1649                 /*
1650                  * Resolve any "missing" vdevs in the current configuration.
1651                  * If we find that the MOS config has more accurate information
1652                  * about the top-level vdev then use that vdev instead.
1653                  */
1654                 if (tvd->vdev_ops == &vdev_missing_ops &&
1655                     mtvd->vdev_ops != &vdev_missing_ops) {
1656 
1657                         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG))
1658                                 continue;
1659 
1660                         /*
1661                          * Device specific actions.
1662                          */
1663                         if (mtvd->vdev_islog) {
1664                                 spa_set_log_state(spa, SPA_LOG_CLEAR);
1665                         } else {
1666                                 /*
1667                                  * XXX - once we have 'readonly' pool
1668                                  * support we should be able to handle
1669                                  * missing data devices by transitioning
1670                                  * the pool to readonly.
1671                                  */
1672                                 continue;
1673                         }
1674 
1675                         /*
1676                          * Swap the missing vdev with the data we were
1677                          * able to obtain from the MOS config.
1678                          */
1679                         vdev_remove_child(rvd, tvd);
1680                         vdev_remove_child(mrvd, mtvd);
1681 
1682                         vdev_add_child(rvd, mtvd);
1683                         vdev_add_child(mrvd, tvd);
1684 
1685                         spa_config_exit(spa, SCL_ALL, FTAG);
1686                         vdev_load(mtvd);
1687                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1688 
1689                         vdev_reopen(rvd);
1690                 } else if (mtvd->vdev_islog) {
1691                         /*
1692                          * Load the slog device's state from the MOS config
1693                          * since it's possible that the label does not
1694                          * contain the most up-to-date information.
1695                          */
1696                         vdev_load_log_state(tvd, mtvd);
1697                         vdev_reopen(tvd);
1698                 }
1699         }
1700         vdev_free(mrvd);
1701         spa_config_exit(spa, SCL_ALL, FTAG);
1702 
1703         /*
1704          * Ensure we were able to validate the config.
1705          */
1706         return (rvd->vdev_guid_sum == spa->spa_uberblock.ub_guid_sum);
1707 }
1708 
1709 /*
1710  * Check for missing log devices
1711  */
1712 static boolean_t
1713 spa_check_logs(spa_t *spa)
1714 {
1715         boolean_t rv = B_FALSE;
1716 
1717         switch (spa->spa_log_state) {
1718         case SPA_LOG_MISSING:
1719                 /* need to recheck in case slog has been restored */
1720         case SPA_LOG_UNKNOWN:
1721                 rv = (dmu_objset_find(spa->spa_name, zil_check_log_chain,
1722                     NULL, DS_FIND_CHILDREN) != 0);
1723                 if (rv)
1724                         spa_set_log_state(spa, SPA_LOG_MISSING);
1725                 break;
1726         }
1727         return (rv);
1728 }
1729 
1730 static boolean_t
1731 spa_passivate_log(spa_t *spa)
1732 {
1733         vdev_t *rvd = spa->spa_root_vdev;
1734         boolean_t slog_found = B_FALSE;
1735 
1736         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1737 
1738         if (!spa_has_slogs(spa))
1739                 return (B_FALSE);
1740 
1741         for (int c = 0; c < rvd->vdev_children; c++) {
1742                 vdev_t *tvd = rvd->vdev_child[c];
1743                 metaslab_group_t *mg = tvd->vdev_mg;
1744 
1745                 if (tvd->vdev_islog) {
1746                         metaslab_group_passivate(mg);
1747                         slog_found = B_TRUE;
1748                 }
1749         }
1750 
1751         return (slog_found);
1752 }
1753 
1754 static void
1755 spa_activate_log(spa_t *spa)
1756 {
1757         vdev_t *rvd = spa->spa_root_vdev;
1758 
1759         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1760 
1761         for (int c = 0; c < rvd->vdev_children; c++) {
1762                 vdev_t *tvd = rvd->vdev_child[c];
1763                 metaslab_group_t *mg = tvd->vdev_mg;
1764 
1765                 if (tvd->vdev_islog)
1766                         metaslab_group_activate(mg);
1767         }
1768 }
1769 
1770 int
1771 spa_offline_log(spa_t *spa)
1772 {
1773         int error;
1774 
1775         error = dmu_objset_find(spa_name(spa), zil_vdev_offline,
1776             NULL, DS_FIND_CHILDREN);
1777         if (error == 0) {
1778                 /*
1779                  * We successfully offlined the log device, sync out the
1780                  * current txg so that the "stubby" block can be removed
1781                  * by zil_sync().
1782                  */
1783                 txg_wait_synced(spa->spa_dsl_pool, 0);
1784         }
1785         return (error);
1786 }
1787 
1788 static void
1789 spa_aux_check_removed(spa_aux_vdev_t *sav)
1790 {
1791         for (int i = 0; i < sav->sav_count; i++)
1792                 spa_check_removed(sav->sav_vdevs[i]);
1793 }
1794 
1795 void
1796 spa_claim_notify(zio_t *zio)
1797 {
1798         spa_t *spa = zio->io_spa;
1799 
1800         if (zio->io_error)
1801                 return;
1802 
1803         mutex_enter(&spa->spa_props_lock);       /* any mutex will do */
1804         if (spa->spa_claim_max_txg < zio->io_bp->blk_birth)
1805                 spa->spa_claim_max_txg = zio->io_bp->blk_birth;
1806         mutex_exit(&spa->spa_props_lock);
1807 }
1808 
1809 typedef struct spa_load_error {
1810         uint64_t        sle_meta_count;
1811         uint64_t        sle_data_count;
1812 } spa_load_error_t;
1813 
1814 static void
1815 spa_load_verify_done(zio_t *zio)
1816 {
1817         blkptr_t *bp = zio->io_bp;
1818         spa_load_error_t *sle = zio->io_private;
1819         dmu_object_type_t type = BP_GET_TYPE(bp);
1820         int error = zio->io_error;
1821         spa_t *spa = zio->io_spa;
1822 
1823         if (error) {
1824                 if ((BP_GET_LEVEL(bp) != 0 || DMU_OT_IS_METADATA(type)) &&
1825                     type != DMU_OT_INTENT_LOG)
1826                         atomic_inc_64(&sle->sle_meta_count);
1827                 else
1828                         atomic_inc_64(&sle->sle_data_count);
1829         }
1830         zio_data_buf_free(zio->io_data, zio->io_size);
1831 
1832         mutex_enter(&spa->spa_scrub_lock);
1833         spa->spa_scrub_inflight--;
1834         cv_broadcast(&spa->spa_scrub_io_cv);
1835         mutex_exit(&spa->spa_scrub_lock);
1836 }
1837 
1838 /*
1839  * Maximum number of concurrent scrub i/os to create while verifying
1840  * a pool while importing it.
1841  */
1842 int spa_load_verify_maxinflight = 10000;
1843 boolean_t spa_load_verify_metadata = B_TRUE;
1844 boolean_t spa_load_verify_data = B_TRUE;
1845 
1846 /*ARGSUSED*/
1847 static int
1848 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1849     const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
1850 {
1851         if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp))
1852                 return (0);
1853         /*
1854          * Note: normally this routine will not be called if
1855          * spa_load_verify_metadata is not set.  However, it may be useful
1856          * to manually set the flag after the traversal has begun.
1857          */
1858         if (!spa_load_verify_metadata)
1859                 return (0);
1860         if (BP_GET_BUFC_TYPE(bp) == ARC_BUFC_DATA && !spa_load_verify_data)
1861                 return (0);
1862 
1863         zio_t *rio = arg;
1864         size_t size = BP_GET_PSIZE(bp);
1865         void *data = zio_data_buf_alloc(size);
1866 
1867         mutex_enter(&spa->spa_scrub_lock);
1868         while (spa->spa_scrub_inflight >= spa_load_verify_maxinflight)
1869                 cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock);
1870         spa->spa_scrub_inflight++;
1871         mutex_exit(&spa->spa_scrub_lock);
1872 
1873         zio_nowait(zio_read(rio, spa, bp, data, size,
1874             spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
1875             ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
1876             ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
1877         return (0);
1878 }
1879 
1880 static int
1881 spa_load_verify(spa_t *spa)
1882 {
1883         zio_t *rio;
1884         spa_load_error_t sle = { 0 };
1885         zpool_rewind_policy_t policy;
1886         boolean_t verify_ok = B_FALSE;
1887         int error = 0;
1888 
1889         zpool_get_rewind_policy(spa->spa_config, &policy);
1890 
1891         if (policy.zrp_request & ZPOOL_NEVER_REWIND)
1892                 return (0);
1893 
1894         rio = zio_root(spa, NULL, &sle,
1895             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1896 
1897         if (spa_load_verify_metadata) {
1898                 error = traverse_pool(spa, spa->spa_verify_min_txg,
1899                     TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA,
1900                     spa_load_verify_cb, rio);
1901         }
1902 
1903         (void) zio_wait(rio);
1904 
1905         spa->spa_load_meta_errors = sle.sle_meta_count;
1906         spa->spa_load_data_errors = sle.sle_data_count;
1907 
1908         if (!error && sle.sle_meta_count <= policy.zrp_maxmeta &&
1909             sle.sle_data_count <= policy.zrp_maxdata) {
1910                 int64_t loss = 0;
1911 
1912                 verify_ok = B_TRUE;
1913                 spa->spa_load_txg = spa->spa_uberblock.ub_txg;
1914                 spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
1915 
1916                 loss = spa->spa_last_ubsync_txg_ts - spa->spa_load_txg_ts;
1917                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1918                     ZPOOL_CONFIG_LOAD_TIME, spa->spa_load_txg_ts) == 0);
1919                 VERIFY(nvlist_add_int64(spa->spa_load_info,
1920                     ZPOOL_CONFIG_REWIND_TIME, loss) == 0);
1921                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1922                     ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count) == 0);
1923         } else {
1924                 spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
1925         }
1926 
1927         if (error) {
1928                 if (error != ENXIO && error != EIO)
1929                         error = SET_ERROR(EIO);
1930                 return (error);
1931         }
1932 
1933         return (verify_ok ? 0 : EIO);
1934 }
1935 
1936 /*
1937  * Find a value in the pool props object.
1938  */
1939 static void
1940 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
1941 {
1942         (void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
1943             zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
1944 }
1945 
1946 /*
1947  * Find a value in the pool directory object.
1948  */
1949 static int
1950 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val)
1951 {
1952         return (zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1953             name, sizeof (uint64_t), 1, val));
1954 }
1955 
1956 static int
1957 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
1958 {
1959         vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
1960         return (err);
1961 }
1962 
1963 /*
1964  * Fix up config after a partly-completed split.  This is done with the
1965  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
1966  * pool have that entry in their config, but only the splitting one contains
1967  * a list of all the guids of the vdevs that are being split off.
1968  *
1969  * This function determines what to do with that list: either rejoin
1970  * all the disks to the pool, or complete the splitting process.  To attempt
1971  * the rejoin, each disk that is offlined is marked online again, and
1972  * we do a reopen() call.  If the vdev label for every disk that was
1973  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
1974  * then we call vdev_split() on each disk, and complete the split.
1975  *
1976  * Otherwise we leave the config alone, with all the vdevs in place in
1977  * the original pool.
1978  */
1979 static void
1980 spa_try_repair(spa_t *spa, nvlist_t *config)
1981 {
1982         uint_t extracted;
1983         uint64_t *glist;
1984         uint_t i, gcount;
1985         nvlist_t *nvl;
1986         vdev_t **vd;
1987         boolean_t attempt_reopen;
1988 
1989         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
1990                 return;
1991 
1992         /* check that the config is complete */
1993         if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
1994             &glist, &gcount) != 0)
1995                 return;
1996 
1997         vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
1998 
1999         /* attempt to online all the vdevs & validate */
2000         attempt_reopen = B_TRUE;
2001         for (i = 0; i < gcount; i++) {
2002                 if (glist[i] == 0)      /* vdev is hole */
2003                         continue;
2004 
2005                 vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
2006                 if (vd[i] == NULL) {
2007                         /*
2008                          * Don't bother attempting to reopen the disks;
2009                          * just do the split.
2010                          */
2011                         attempt_reopen = B_FALSE;
2012                 } else {
2013                         /* attempt to re-online it */
2014                         vd[i]->vdev_offline = B_FALSE;
2015                 }
2016         }
2017 
2018         if (attempt_reopen) {
2019                 vdev_reopen(spa->spa_root_vdev);
2020 
2021                 /* check each device to see what state it's in */
2022                 for (extracted = 0, i = 0; i < gcount; i++) {
2023                         if (vd[i] != NULL &&
2024                             vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
2025                                 break;
2026                         ++extracted;
2027                 }
2028         }
2029 
2030         /*
2031          * If every disk has been moved to the new pool, or if we never
2032          * even attempted to look at them, then we split them off for
2033          * good.
2034          */
2035         if (!attempt_reopen || gcount == extracted) {
2036                 for (i = 0; i < gcount; i++)
2037                         if (vd[i] != NULL)
2038                                 vdev_split(vd[i]);
2039                 vdev_reopen(spa->spa_root_vdev);
2040         }
2041 
2042         kmem_free(vd, gcount * sizeof (vdev_t *));
2043 }
2044 
2045 static int
2046 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
2047     boolean_t mosconfig)
2048 {
2049         nvlist_t *config = spa->spa_config;
2050         char *ereport = FM_EREPORT_ZFS_POOL;
2051         char *comment;
2052         int error;
2053         uint64_t pool_guid;
2054         nvlist_t *nvl;
2055 
2056         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
2057                 return (SET_ERROR(EINVAL));
2058 
2059         ASSERT(spa->spa_comment == NULL);
2060         if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
2061                 spa->spa_comment = spa_strdup(comment);
2062 
2063         /*
2064          * Versioning wasn't explicitly added to the label until later, so if
2065          * it's not present treat it as the initial version.
2066          */
2067         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
2068             &spa->spa_ubsync.ub_version) != 0)
2069                 spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
2070 
2071         (void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
2072             &spa->spa_config_txg);
2073 
2074         if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
2075             spa_guid_exists(pool_guid, 0)) {
2076                 error = SET_ERROR(EEXIST);
2077         } else {
2078                 spa->spa_config_guid = pool_guid;
2079 
2080                 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT,
2081                     &nvl) == 0) {
2082                         VERIFY(nvlist_dup(nvl, &spa->spa_config_splitting,
2083                             KM_SLEEP) == 0);
2084                 }
2085 
2086                 nvlist_free(spa->spa_load_info);
2087                 spa->spa_load_info = fnvlist_alloc();
2088 
2089                 gethrestime(&spa->spa_loaded_ts);
2090                 error = spa_load_impl(spa, pool_guid, config, state, type,
2091                     mosconfig, &ereport);
2092         }
2093 
2094         spa->spa_minref = refcount_count(&spa->spa_refcount);
2095         if (error) {
2096                 if (error != EEXIST) {
2097                         spa->spa_loaded_ts.tv_sec = 0;
2098                         spa->spa_loaded_ts.tv_nsec = 0;
2099                 }
2100                 if (error != EBADF) {
2101                         zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
2102                 }
2103         }
2104         spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
2105         spa->spa_ena = 0;
2106 
2107         return (error);
2108 }
2109 
2110 /*
2111  * Load an existing storage pool, using the pool's builtin spa_config as a
2112  * source of configuration information.
2113  */
2114 static int
2115 spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config,
2116     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
2117     char **ereport)
2118 {
2119         int error = 0;
2120         nvlist_t *nvroot = NULL;
2121         nvlist_t *label;
2122         vdev_t *rvd;
2123         uberblock_t *ub = &spa->spa_uberblock;
2124         uint64_t children, config_cache_txg = spa->spa_config_txg;
2125         int orig_mode = spa->spa_mode;
2126         int parse;
2127         uint64_t obj;
2128         boolean_t missing_feat_write = B_FALSE;
2129 
2130         /*
2131          * If this is an untrusted config, access the pool in read-only mode.
2132          * This prevents things like resilvering recently removed devices.
2133          */
2134         if (!mosconfig)
2135                 spa->spa_mode = FREAD;
2136 
2137         ASSERT(MUTEX_HELD(&spa_namespace_lock));
2138 
2139         spa->spa_load_state = state;
2140 
2141         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot))
2142                 return (SET_ERROR(EINVAL));
2143 
2144         parse = (type == SPA_IMPORT_EXISTING ?
2145             VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
2146 
2147         /*
2148          * Create "The Godfather" zio to hold all async IOs
2149          */
2150         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
2151             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
2152 
2153         /*
2154          * Parse the configuration into a vdev tree.  We explicitly set the
2155          * value that will be returned by spa_version() since parsing the
2156          * configuration requires knowing the version number.
2157          */
2158         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2159         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, parse);
2160         spa_config_exit(spa, SCL_ALL, FTAG);
2161 
2162         if (error != 0)
2163                 return (error);
2164 
2165         ASSERT(spa->spa_root_vdev == rvd);
2166 
2167         if (type != SPA_IMPORT_ASSEMBLE) {
2168                 ASSERT(spa_guid(spa) == pool_guid);
2169         }
2170 
2171         /*
2172          * Try to open all vdevs, loading each label in the process.
2173          */
2174         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2175         error = vdev_open(rvd);
2176         spa_config_exit(spa, SCL_ALL, FTAG);
2177         if (error != 0)
2178                 return (error);
2179 
2180         /*
2181          * We need to validate the vdev labels against the configuration that
2182          * we have in hand, which is dependent on the setting of mosconfig. If
2183          * mosconfig is true then we're validating the vdev labels based on
2184          * that config.  Otherwise, we're validating against the cached config
2185          * (zpool.cache) that was read when we loaded the zfs module, and then
2186          * later we will recursively call spa_load() and validate against
2187          * the vdev config.
2188          *
2189          * If we're assembling a new pool that's been split off from an
2190          * existing pool, the labels haven't yet been updated so we skip
2191          * validation for now.
2192          */
2193         if (type != SPA_IMPORT_ASSEMBLE) {
2194                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2195                 error = vdev_validate(rvd, mosconfig);
2196                 spa_config_exit(spa, SCL_ALL, FTAG);
2197 
2198                 if (error != 0)
2199                         return (error);
2200 
2201                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2202                         return (SET_ERROR(ENXIO));
2203         }
2204 
2205         /*
2206          * Find the best uberblock.
2207          */
2208         vdev_uberblock_load(rvd, ub, &label);
2209 
2210         /*
2211          * If we weren't able to find a single valid uberblock, return failure.
2212          */
2213         if (ub->ub_txg == 0) {
2214                 nvlist_free(label);
2215                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
2216         }
2217 
2218         /*
2219          * If the pool has an unsupported version we can't open it.
2220          */
2221         if (!SPA_VERSION_IS_SUPPORTED(ub->ub_version)) {
2222                 nvlist_free(label);
2223                 return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
2224         }
2225 
2226         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2227                 nvlist_t *features;
2228 
2229                 /*
2230                  * If we weren't able to find what's necessary for reading the
2231                  * MOS in the label, return failure.
2232                  */
2233                 if (label == NULL || nvlist_lookup_nvlist(label,
2234                     ZPOOL_CONFIG_FEATURES_FOR_READ, &features) != 0) {
2235                         nvlist_free(label);
2236                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2237                             ENXIO));
2238                 }
2239 
2240                 /*
2241                  * Update our in-core representation with the definitive values
2242                  * from the label.
2243                  */
2244                 nvlist_free(spa->spa_label_features);
2245                 VERIFY(nvlist_dup(features, &spa->spa_label_features, 0) == 0);
2246         }
2247 
2248         nvlist_free(label);
2249 
2250         /*
2251          * Look through entries in the label nvlist's features_for_read. If
2252          * there is a feature listed there which we don't understand then we
2253          * cannot open a pool.
2254          */
2255         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2256                 nvlist_t *unsup_feat;
2257 
2258                 VERIFY(nvlist_alloc(&unsup_feat, NV_UNIQUE_NAME, KM_SLEEP) ==
2259                     0);
2260 
2261                 for (nvpair_t *nvp = nvlist_next_nvpair(spa->spa_label_features,
2262                     NULL); nvp != NULL;
2263                     nvp = nvlist_next_nvpair(spa->spa_label_features, nvp)) {
2264                         if (!zfeature_is_supported(nvpair_name(nvp))) {
2265                                 VERIFY(nvlist_add_string(unsup_feat,
2266                                     nvpair_name(nvp), "") == 0);
2267                         }
2268                 }
2269 
2270                 if (!nvlist_empty(unsup_feat)) {
2271                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
2272                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat) == 0);
2273                         nvlist_free(unsup_feat);
2274                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2275                             ENOTSUP));
2276                 }
2277 
2278                 nvlist_free(unsup_feat);
2279         }
2280 
2281         /*
2282          * If the vdev guid sum doesn't match the uberblock, we have an
2283          * incomplete configuration.  We first check to see if the pool
2284          * is aware of the complete config (i.e ZPOOL_CONFIG_VDEV_CHILDREN).
2285          * If it is, defer the vdev_guid_sum check till later so we
2286          * can handle missing vdevs.
2287          */
2288         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN,
2289             &children) != 0 && mosconfig && type != SPA_IMPORT_ASSEMBLE &&
2290             rvd->vdev_guid_sum != ub->ub_guid_sum)
2291                 return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
2292 
2293         if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
2294                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2295                 spa_try_repair(spa, config);
2296                 spa_config_exit(spa, SCL_ALL, FTAG);
2297                 nvlist_free(spa->spa_config_splitting);
2298                 spa->spa_config_splitting = NULL;
2299         }
2300 
2301         /*
2302          * Initialize internal SPA structures.
2303          */
2304         spa->spa_state = POOL_STATE_ACTIVE;
2305         spa->spa_ubsync = spa->spa_uberblock;
2306         spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
2307             TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
2308         spa->spa_first_txg = spa->spa_last_ubsync_txg ?
2309             spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
2310         spa->spa_claim_max_txg = spa->spa_first_txg;
2311         spa->spa_prev_software_version = ub->ub_software_version;
2312 
2313         error = dsl_pool_init(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
2314         if (error)
2315                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2316         spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
2317 
2318         if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object) != 0)
2319                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2320 
2321         if (spa_version(spa) >= SPA_VERSION_FEATURES) {
2322                 boolean_t missing_feat_read = B_FALSE;
2323                 nvlist_t *unsup_feat, *enabled_feat;
2324 
2325                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_READ,
2326                     &spa->spa_feat_for_read_obj) != 0) {
2327                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2328                 }
2329 
2330                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_WRITE,
2331                     &spa->spa_feat_for_write_obj) != 0) {
2332                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2333                 }
2334 
2335                 if (spa_dir_prop(spa, DMU_POOL_FEATURE_DESCRIPTIONS,
2336                     &spa->spa_feat_desc_obj) != 0) {
2337                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2338                 }
2339 
2340                 enabled_feat = fnvlist_alloc();
2341                 unsup_feat = fnvlist_alloc();
2342 
2343                 if (!spa_features_check(spa, B_FALSE,
2344                     unsup_feat, enabled_feat))
2345                         missing_feat_read = B_TRUE;
2346 
2347                 if (spa_writeable(spa) || state == SPA_LOAD_TRYIMPORT) {
2348                         if (!spa_features_check(spa, B_TRUE,
2349                             unsup_feat, enabled_feat)) {
2350                                 missing_feat_write = B_TRUE;
2351                         }
2352                 }
2353 
2354                 fnvlist_add_nvlist(spa->spa_load_info,
2355                     ZPOOL_CONFIG_ENABLED_FEAT, enabled_feat);
2356 
2357                 if (!nvlist_empty(unsup_feat)) {
2358                         fnvlist_add_nvlist(spa->spa_load_info,
2359                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
2360                 }
2361 
2362                 fnvlist_free(enabled_feat);
2363                 fnvlist_free(unsup_feat);
2364 
2365                 if (!missing_feat_read) {
2366                         fnvlist_add_boolean(spa->spa_load_info,
2367                             ZPOOL_CONFIG_CAN_RDONLY);
2368                 }
2369 
2370                 /*
2371                  * If the state is SPA_LOAD_TRYIMPORT, our objective is
2372                  * twofold: to determine whether the pool is available for
2373                  * import in read-write mode and (if it is not) whether the
2374                  * pool is available for import in read-only mode. If the pool
2375                  * is available for import in read-write mode, it is displayed
2376                  * as available in userland; if it is not available for import
2377                  * in read-only mode, it is displayed as unavailable in
2378                  * userland. If the pool is available for import in read-only
2379                  * mode but not read-write mode, it is displayed as unavailable
2380                  * in userland with a special note that the pool is actually
2381                  * available for open in read-only mode.
2382                  *
2383                  * As a result, if the state is SPA_LOAD_TRYIMPORT and we are
2384                  * missing a feature for write, we must first determine whether
2385                  * the pool can be opened read-only before returning to
2386                  * userland in order to know whether to display the
2387                  * abovementioned note.
2388                  */
2389                 if (missing_feat_read || (missing_feat_write &&
2390                     spa_writeable(spa))) {
2391                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2392                             ENOTSUP));
2393                 }
2394 
2395                 /*
2396                  * Load refcounts for ZFS features from disk into an in-memory
2397                  * cache during SPA initialization.
2398                  */
2399                 for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
2400                         uint64_t refcount;
2401 
2402                         error = feature_get_refcount_from_disk(spa,
2403                             &spa_feature_table[i], &refcount);
2404                         if (error == 0) {
2405                                 spa->spa_feat_refcount_cache[i] = refcount;
2406                         } else if (error == ENOTSUP) {
2407                                 spa->spa_feat_refcount_cache[i] =
2408                                     SPA_FEATURE_DISABLED;
2409                         } else {
2410                                 return (spa_vdev_err(rvd,
2411                                     VDEV_AUX_CORRUPT_DATA, EIO));
2412                         }
2413                 }
2414         }
2415 
2416         if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
2417                 if (spa_dir_prop(spa, DMU_POOL_FEATURE_ENABLED_TXG,
2418                     &spa->spa_feat_enabled_txg_obj) != 0)
2419                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2420         }
2421 
2422         spa->spa_is_initializing = B_TRUE;
2423         error = dsl_pool_open(spa->spa_dsl_pool);
2424         spa->spa_is_initializing = B_FALSE;
2425         if (error != 0)
2426                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2427 
2428         if (!mosconfig) {
2429                 uint64_t hostid;
2430                 nvlist_t *policy = NULL, *nvconfig;
2431 
2432                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2433                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2434 
2435                 if (!spa_is_root(spa) && nvlist_lookup_uint64(nvconfig,
2436                     ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
2437                         char *hostname;
2438                         unsigned long myhostid = 0;
2439 
2440                         VERIFY(nvlist_lookup_string(nvconfig,
2441                             ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
2442 
2443 #ifdef  _KERNEL
2444                         myhostid = zone_get_hostid(NULL);
2445 #else   /* _KERNEL */
2446                         /*
2447                          * We're emulating the system's hostid in userland, so
2448                          * we can't use zone_get_hostid().
2449                          */
2450                         (void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
2451 #endif  /* _KERNEL */
2452                         if (hostid != 0 && myhostid != 0 &&
2453                             hostid != myhostid) {
2454                                 nvlist_free(nvconfig);
2455                                 cmn_err(CE_WARN, "pool '%s' could not be "
2456                                     "loaded as it was last accessed by "
2457                                     "another system (host: %s hostid: 0x%lx). "
2458                                     "See: http://illumos.org/msg/ZFS-8000-EY",
2459                                     spa_name(spa), hostname,
2460                                     (unsigned long)hostid);
2461                                 return (SET_ERROR(EBADF));
2462                         }
2463                 }
2464                 if (nvlist_lookup_nvlist(spa->spa_config,
2465                     ZPOOL_REWIND_POLICY, &policy) == 0)
2466                         VERIFY(nvlist_add_nvlist(nvconfig,
2467                             ZPOOL_REWIND_POLICY, policy) == 0);
2468 
2469                 spa_config_set(spa, nvconfig);
2470                 spa_unload(spa);
2471                 spa_deactivate(spa);
2472                 spa_activate(spa, orig_mode);
2473 
2474                 return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
2475         }
2476 
2477         if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj) != 0)
2478                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2479         error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
2480         if (error != 0)
2481                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2482 
2483         /*
2484          * Load the bit that tells us to use the new accounting function
2485          * (raid-z deflation).  If we have an older pool, this will not
2486          * be present.
2487          */
2488         error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate);
2489         if (error != 0 && error != ENOENT)
2490                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2491 
2492         error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
2493             &spa->spa_creation_version);
2494         if (error != 0 && error != ENOENT)
2495                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2496 
2497         /*
2498          * Load the persistent error log.  If we have an older pool, this will
2499          * not be present.
2500          */
2501         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last);
2502         if (error != 0 && error != ENOENT)
2503                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2504 
2505         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
2506             &spa->spa_errlog_scrub);
2507         if (error != 0 && error != ENOENT)
2508                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2509 
2510         /*
2511          * Load the history object.  If we have an older pool, this
2512          * will not be present.
2513          */
2514         error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history);
2515         if (error != 0 && error != ENOENT)
2516                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2517 
2518         /*
2519          * If we're assembling the pool from the split-off vdevs of
2520          * an existing pool, we don't want to attach the spares & cache
2521          * devices.
2522          */
2523 
2524         /*
2525          * Load any hot spares for this pool.
2526          */
2527         error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object);
2528         if (error != 0 && error != ENOENT)
2529                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2530         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2531                 ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
2532                 if (load_nvlist(spa, spa->spa_spares.sav_object,
2533                     &spa->spa_spares.sav_config) != 0)
2534                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2535 
2536                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2537                 spa_load_spares(spa);
2538                 spa_config_exit(spa, SCL_ALL, FTAG);
2539         } else if (error == 0) {
2540                 spa->spa_spares.sav_sync = B_TRUE;
2541         }
2542 
2543         /*
2544          * Load any level 2 ARC devices for this pool.
2545          */
2546         error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
2547             &spa->spa_l2cache.sav_object);
2548         if (error != 0 && error != ENOENT)
2549                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2550         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2551                 ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
2552                 if (load_nvlist(spa, spa->spa_l2cache.sav_object,
2553                     &spa->spa_l2cache.sav_config) != 0)
2554                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2555 
2556                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2557                 spa_load_l2cache(spa);
2558                 spa_config_exit(spa, SCL_ALL, FTAG);
2559         } else if (error == 0) {
2560                 spa->spa_l2cache.sav_sync = B_TRUE;
2561         }
2562 
2563         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2564 
2565         error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object);
2566         if (error && error != ENOENT)
2567                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2568 
2569         if (error == 0) {
2570                 uint64_t autoreplace;
2571 
2572                 spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
2573                 spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
2574                 spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
2575                 spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
2576                 spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
2577                 spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
2578                     &spa->spa_dedup_ditto);
2579 
2580                 spa->spa_autoreplace = (autoreplace != 0);
2581         }
2582 
2583         /*
2584          * If the 'autoreplace' property is set, then post a resource notifying
2585          * the ZFS DE that it should not issue any faults for unopenable
2586          * devices.  We also iterate over the vdevs, and post a sysevent for any
2587          * unopenable vdevs so that the normal autoreplace handler can take
2588          * over.
2589          */
2590         if (spa->spa_autoreplace && state != SPA_LOAD_TRYIMPORT) {
2591                 spa_check_removed(spa->spa_root_vdev);
2592                 /*
2593                  * For the import case, this is done in spa_import(), because
2594                  * at this point we're using the spare definitions from
2595                  * the MOS config, not necessarily from the userland config.
2596                  */
2597                 if (state != SPA_LOAD_IMPORT) {
2598                         spa_aux_check_removed(&spa->spa_spares);
2599                         spa_aux_check_removed(&spa->spa_l2cache);
2600                 }
2601         }
2602 
2603         /*
2604          * Load the vdev state for all toplevel vdevs.
2605          */
2606         vdev_load(rvd);
2607 
2608         /*
2609          * Propagate the leaf DTLs we just loaded all the way up the tree.
2610          */
2611         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2612         vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
2613         spa_config_exit(spa, SCL_ALL, FTAG);
2614 
2615         /*
2616          * Load the DDTs (dedup tables).
2617          */
2618         error = ddt_load(spa);
2619         if (error != 0)
2620                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2621 
2622         spa_update_dspace(spa);
2623 
2624         /*
2625          * Validate the config, using the MOS config to fill in any
2626          * information which might be missing.  If we fail to validate
2627          * the config then declare the pool unfit for use. If we're
2628          * assembling a pool from a split, the log is not transferred
2629          * over.
2630          */
2631         if (type != SPA_IMPORT_ASSEMBLE) {
2632                 nvlist_t *nvconfig;
2633 
2634                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2635                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2636 
2637                 if (!spa_config_valid(spa, nvconfig)) {
2638                         nvlist_free(nvconfig);
2639                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
2640                             ENXIO));
2641                 }
2642                 nvlist_free(nvconfig);
2643 
2644                 /*
2645                  * Now that we've validated the config, check the state of the
2646                  * root vdev.  If it can't be opened, it indicates one or
2647                  * more toplevel vdevs are faulted.
2648                  */
2649                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2650                         return (SET_ERROR(ENXIO));
2651 
2652                 if (spa_check_logs(spa)) {
2653                         *ereport = FM_EREPORT_ZFS_LOG_REPLAY;
2654                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG, ENXIO));
2655                 }
2656         }
2657 
2658         if (missing_feat_write) {
2659                 ASSERT(state == SPA_LOAD_TRYIMPORT);
2660 
2661                 /*
2662                  * At this point, we know that we can open the pool in
2663                  * read-only mode but not read-write mode. We now have enough
2664                  * information and can return to userland.
2665                  */
2666                 return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT, ENOTSUP));
2667         }
2668 
2669         /*
2670          * We've successfully opened the pool, verify that we're ready
2671          * to start pushing transactions.
2672          */
2673         if (state != SPA_LOAD_TRYIMPORT) {
2674                 if (error = spa_load_verify(spa))
2675                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2676                             error));
2677         }
2678 
2679         if (spa_writeable(spa) && (state == SPA_LOAD_RECOVER ||
2680             spa->spa_load_max_txg == UINT64_MAX)) {
2681                 dmu_tx_t *tx;
2682                 int need_update = B_FALSE;
2683 
2684                 ASSERT(state != SPA_LOAD_TRYIMPORT);
2685 
2686                 /*
2687                  * Claim log blocks that haven't been committed yet.
2688                  * This must all happen in a single txg.
2689                  * Note: spa_claim_max_txg is updated by spa_claim_notify(),
2690                  * invoked from zil_claim_log_block()'s i/o done callback.
2691                  * Price of rollback is that we abandon the log.
2692                  */
2693                 spa->spa_claiming = B_TRUE;
2694 
2695                 tx = dmu_tx_create_assigned(spa_get_dsl(spa),
2696                     spa_first_txg(spa));
2697                 (void) dmu_objset_find(spa_name(spa),
2698                     zil_claim, tx, DS_FIND_CHILDREN);
2699                 dmu_tx_commit(tx);
2700 
2701                 spa->spa_claiming = B_FALSE;
2702 
2703                 spa_set_log_state(spa, SPA_LOG_GOOD);
2704                 spa->spa_sync_on = B_TRUE;
2705                 txg_sync_start(spa->spa_dsl_pool);
2706 
2707                 /*
2708                  * Wait for all claims to sync.  We sync up to the highest
2709                  * claimed log block birth time so that claimed log blocks
2710                  * don't appear to be from the future.  spa_claim_max_txg
2711                  * will have been set for us by either zil_check_log_chain()
2712                  * (invoked from spa_check_logs()) or zil_claim() above.
2713                  */
2714                 txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
2715 
2716                 /*
2717                  * If the config cache is stale, or we have uninitialized
2718                  * metaslabs (see spa_vdev_add()), then update the config.
2719                  *
2720                  * If this is a verbatim import, trust the current
2721                  * in-core spa_config and update the disk labels.
2722                  */
2723                 if (config_cache_txg != spa->spa_config_txg ||
2724                     state == SPA_LOAD_IMPORT ||
2725                     state == SPA_LOAD_RECOVER ||
2726                     (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
2727                         need_update = B_TRUE;
2728 
2729                 for (int c = 0; c < rvd->vdev_children; c++)
2730                         if (rvd->vdev_child[c]->vdev_ms_array == 0)
2731                                 need_update = B_TRUE;
2732 
2733                 /*
2734                  * Update the config cache asychronously in case we're the
2735                  * root pool, in which case the config cache isn't writable yet.
2736                  */
2737                 if (need_update)
2738                         spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2739 
2740                 /*
2741                  * Check all DTLs to see if anything needs resilvering.
2742                  */
2743                 if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
2744                     vdev_resilver_needed(rvd, NULL, NULL))
2745                         spa_async_request(spa, SPA_ASYNC_RESILVER);
2746 
2747                 /*
2748                  * Log the fact that we booted up (so that we can detect if
2749                  * we rebooted in the middle of an operation).
2750                  */
2751                 spa_history_log_version(spa, "open");
2752 
2753                 /*
2754                  * Delete any inconsistent datasets.
2755                  */
2756                 (void) dmu_objset_find(spa_name(spa),
2757                     dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
2758 
2759                 /*
2760                  * Clean up any stale temporary dataset userrefs.
2761                  */
2762                 dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
2763         }
2764 
2765         return (0);
2766 }
2767 
2768 static int
2769 spa_load_retry(spa_t *spa, spa_load_state_t state, int mosconfig)
2770 {
2771         int mode = spa->spa_mode;
2772 
2773         spa_unload(spa);
2774         spa_deactivate(spa);
2775 
2776         spa->spa_load_max_txg = spa->spa_uberblock.ub_txg - 1;
2777 
2778         spa_activate(spa, mode);
2779         spa_async_suspend(spa);
2780 
2781         return (spa_load(spa, state, SPA_IMPORT_EXISTING, mosconfig));
2782 }
2783 
2784 /*
2785  * If spa_load() fails this function will try loading prior txg's. If
2786  * 'state' is SPA_LOAD_RECOVER and one of these loads succeeds the pool
2787  * will be rewound to that txg. If 'state' is not SPA_LOAD_RECOVER this
2788  * function will not rewind the pool and will return the same error as
2789  * spa_load().
2790  */
2791 static int
2792 spa_load_best(spa_t *spa, spa_load_state_t state, int mosconfig,
2793     uint64_t max_request, int rewind_flags)
2794 {
2795         nvlist_t *loadinfo = NULL;
2796         nvlist_t *config = NULL;
2797         int load_error, rewind_error;
2798         uint64_t safe_rewind_txg;
2799         uint64_t min_txg;
2800 
2801         if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
2802                 spa->spa_load_max_txg = spa->spa_load_txg;
2803                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2804         } else {
2805                 spa->spa_load_max_txg = max_request;
2806                 if (max_request != UINT64_MAX)
2807                         spa->spa_extreme_rewind = B_TRUE;
2808         }
2809 
2810         load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING,
2811             mosconfig);
2812         if (load_error == 0)
2813                 return (0);
2814 
2815         if (spa->spa_root_vdev != NULL)
2816                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2817 
2818         spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
2819         spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
2820 
2821         if (rewind_flags & ZPOOL_NEVER_REWIND) {
2822                 nvlist_free(config);
2823                 return (load_error);
2824         }
2825 
2826         if (state == SPA_LOAD_RECOVER) {
2827                 /* Price of rolling back is discarding txgs, including log */
2828                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2829         } else {
2830                 /*
2831                  * If we aren't rolling back save the load info from our first
2832                  * import attempt so that we can restore it after attempting
2833                  * to rewind.
2834                  */
2835                 loadinfo = spa->spa_load_info;
2836                 spa->spa_load_info = fnvlist_alloc();
2837         }
2838 
2839         spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
2840         safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
2841         min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
2842             TXG_INITIAL : safe_rewind_txg;
2843 
2844         /*
2845          * Continue as long as we're finding errors, we're still within
2846          * the acceptable rewind range, and we're still finding uberblocks
2847          */
2848         while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
2849             spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
2850                 if (spa->spa_load_max_txg < safe_rewind_txg)
2851                         spa->spa_extreme_rewind = B_TRUE;
2852                 rewind_error = spa_load_retry(spa, state, mosconfig);
2853         }
2854 
2855         spa->spa_extreme_rewind = B_FALSE;
2856         spa->spa_load_max_txg = UINT64_MAX;
2857 
2858         if (config && (rewind_error || state != SPA_LOAD_RECOVER))
2859                 spa_config_set(spa, config);
2860 
2861         if (state == SPA_LOAD_RECOVER) {
2862                 ASSERT3P(loadinfo, ==, NULL);
2863                 return (rewind_error);
2864         } else {
2865                 /* Store the rewind info as part of the initial load info */
2866                 fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
2867                     spa->spa_load_info);
2868 
2869                 /* Restore the initial load info */
2870                 fnvlist_free(spa->spa_load_info);
2871                 spa->spa_load_info = loadinfo;
2872 
2873                 return (load_error);
2874         }
2875 }
2876 
2877 /*
2878  * Pool Open/Import
2879  *
2880  * The import case is identical to an open except that the configuration is sent
2881  * down from userland, instead of grabbed from the configuration cache.  For the
2882  * case of an open, the pool configuration will exist in the
2883  * POOL_STATE_UNINITIALIZED state.
2884  *
2885  * The stats information (gen/count/ustats) is used to gather vdev statistics at
2886  * the same time open the pool, without having to keep around the spa_t in some
2887  * ambiguous state.
2888  */
2889 static int
2890 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
2891     nvlist_t **config)
2892 {
2893         spa_t *spa;
2894         spa_load_state_t state = SPA_LOAD_OPEN;
2895         int error;
2896         int locked = B_FALSE;
2897 
2898         *spapp = NULL;
2899 
2900         /*
2901          * As disgusting as this is, we need to support recursive calls to this
2902          * function because dsl_dir_open() is called during spa_load(), and ends
2903          * up calling spa_open() again.  The real fix is to figure out how to
2904          * avoid dsl_dir_open() calling this in the first place.
2905          */
2906         if (mutex_owner(&spa_namespace_lock) != curthread) {
2907                 mutex_enter(&spa_namespace_lock);
2908                 locked = B_TRUE;
2909         }
2910 
2911         if ((spa = spa_lookup(pool)) == NULL) {
2912                 if (locked)
2913                         mutex_exit(&spa_namespace_lock);
2914                 return (SET_ERROR(ENOENT));
2915         }
2916 
2917         if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
2918                 zpool_rewind_policy_t policy;
2919 
2920                 zpool_get_rewind_policy(nvpolicy ? nvpolicy : spa->spa_config,
2921                     &policy);
2922                 if (policy.zrp_request & ZPOOL_DO_REWIND)
2923                         state = SPA_LOAD_RECOVER;
2924 
2925                 spa_activate(spa, spa_mode_global);
2926 
2927                 if (state != SPA_LOAD_RECOVER)
2928                         spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
2929 
2930                 error = spa_load_best(spa, state, B_FALSE, policy.zrp_txg,
2931                     policy.zrp_request);
2932 
2933                 if (error == EBADF) {
2934                         /*
2935                          * If vdev_validate() returns failure (indicated by
2936                          * EBADF), it indicates that one of the vdevs indicates
2937                          * that the pool has been exported or destroyed.  If
2938                          * this is the case, the config cache is out of sync and
2939                          * we should remove the pool from the namespace.
2940                          */
2941                         spa_unload(spa);
2942                         spa_deactivate(spa);
2943                         spa_config_sync(spa, B_TRUE, B_TRUE);
2944                         spa_remove(spa);
2945                         if (locked)
2946                                 mutex_exit(&spa_namespace_lock);
2947                         return (SET_ERROR(ENOENT));
2948                 }
2949 
2950                 if (error) {
2951                         /*
2952                          * We can't open the pool, but we still have useful
2953                          * information: the state of each vdev after the
2954                          * attempted vdev_open().  Return this to the user.
2955                          */
2956                         if (config != NULL && spa->spa_config) {
2957                                 VERIFY(nvlist_dup(spa->spa_config, config,
2958                                     KM_SLEEP) == 0);
2959                                 VERIFY(nvlist_add_nvlist(*config,
2960                                     ZPOOL_CONFIG_LOAD_INFO,
2961                                     spa->spa_load_info) == 0);
2962                         }
2963                         spa_unload(spa);
2964                         spa_deactivate(spa);
2965                         spa->spa_last_open_failed = error;
2966                         if (locked)
2967                                 mutex_exit(&spa_namespace_lock);
2968                         *spapp = NULL;
2969                         return (error);
2970                 }
2971         }
2972 
2973         spa_open_ref(spa, tag);
2974 
2975         if (config != NULL)
2976                 *config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2977 
2978         /*
2979          * If we've recovered the pool, pass back any information we
2980          * gathered while doing the load.
2981          */
2982         if (state == SPA_LOAD_RECOVER) {
2983                 VERIFY(nvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
2984                     spa->spa_load_info) == 0);
2985         }
2986 
2987         if (locked) {
2988                 spa->spa_last_open_failed = 0;
2989                 spa->spa_last_ubsync_txg = 0;
2990                 spa->spa_load_txg = 0;
2991                 mutex_exit(&spa_namespace_lock);
2992         }
2993 
2994         *spapp = spa;
2995 
2996         return (0);
2997 }
2998 
2999 int
3000 spa_open_rewind(const char *name, spa_t **spapp, void *tag, nvlist_t *policy,
3001     nvlist_t **config)
3002 {
3003         return (spa_open_common(name, spapp, tag, policy, config));
3004 }
3005 
3006 int
3007 spa_open(const char *name, spa_t **spapp, void *tag)
3008 {
3009         return (spa_open_common(name, spapp, tag, NULL, NULL));
3010 }
3011 
3012 /*
3013  * Lookup the given spa_t, incrementing the inject count in the process,
3014  * preventing it from being exported or destroyed.
3015  */
3016 spa_t *
3017 spa_inject_addref(char *name)
3018 {
3019         spa_t *spa;
3020 
3021         mutex_enter(&spa_namespace_lock);
3022         if ((spa = spa_lookup(name)) == NULL) {
3023                 mutex_exit(&spa_namespace_lock);
3024                 return (NULL);
3025         }
3026         spa->spa_inject_ref++;
3027         mutex_exit(&spa_namespace_lock);
3028 
3029         return (spa);
3030 }
3031 
3032 void
3033 spa_inject_delref(spa_t *spa)
3034 {
3035         mutex_enter(&spa_namespace_lock);
3036         spa->spa_inject_ref--;
3037         mutex_exit(&spa_namespace_lock);
3038 }
3039 
3040 /*
3041  * Add spares device information to the nvlist.
3042  */
3043 static void
3044 spa_add_spares(spa_t *spa, nvlist_t *config)
3045 {
3046         nvlist_t **spares;
3047         uint_t i, nspares;
3048         nvlist_t *nvroot;
3049         uint64_t guid;
3050         vdev_stat_t *vs;
3051         uint_t vsc;
3052         uint64_t pool;
3053 
3054         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3055 
3056         if (spa->spa_spares.sav_count == 0)
3057                 return;
3058 
3059         VERIFY(nvlist_lookup_nvlist(config,
3060             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3061         VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
3062             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
3063         if (nspares != 0) {
3064                 VERIFY(nvlist_add_nvlist_array(nvroot,
3065                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3066                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
3067                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
3068 
3069                 /*
3070                  * Go through and find any spares which have since been
3071                  * repurposed as an active spare.  If this is the case, update
3072                  * their status appropriately.
3073                  */
3074                 for (i = 0; i < nspares; i++) {
3075                         VERIFY(nvlist_lookup_uint64(spares[i],
3076                             ZPOOL_CONFIG_GUID, &guid) == 0);
3077                         if (spa_spare_exists(guid, &pool, NULL) &&
3078                             pool != 0ULL) {
3079                                 VERIFY(nvlist_lookup_uint64_array(
3080                                     spares[i], ZPOOL_CONFIG_VDEV_STATS,
3081                                     (uint64_t **)&vs, &vsc) == 0);
3082                                 vs->vs_state = VDEV_STATE_CANT_OPEN;
3083                                 vs->vs_aux = VDEV_AUX_SPARED;
3084                         }
3085                 }
3086         }
3087 }
3088 
3089 /*
3090  * Add l2cache device information to the nvlist, including vdev stats.
3091  */
3092 static void
3093 spa_add_l2cache(spa_t *spa, nvlist_t *config)
3094 {
3095         nvlist_t **l2cache;
3096         uint_t i, j, nl2cache;
3097         nvlist_t *nvroot;
3098         uint64_t guid;
3099         vdev_t *vd;
3100         vdev_stat_t *vs;
3101         uint_t vsc;
3102 
3103         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3104 
3105         if (spa->spa_l2cache.sav_count == 0)
3106                 return;
3107 
3108         VERIFY(nvlist_lookup_nvlist(config,
3109             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3110         VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
3111             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3112         if (nl2cache != 0) {
3113                 VERIFY(nvlist_add_nvlist_array(nvroot,
3114                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3115                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
3116                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3117 
3118                 /*
3119                  * Update level 2 cache device stats.
3120                  */
3121 
3122                 for (i = 0; i < nl2cache; i++) {
3123                         VERIFY(nvlist_lookup_uint64(l2cache[i],
3124                             ZPOOL_CONFIG_GUID, &guid) == 0);
3125 
3126                         vd = NULL;
3127                         for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
3128                                 if (guid ==
3129                                     spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
3130                                         vd = spa->spa_l2cache.sav_vdevs[j];
3131                                         break;
3132                                 }
3133                         }
3134                         ASSERT(vd != NULL);
3135 
3136                         VERIFY(nvlist_lookup_uint64_array(l2cache[i],
3137                             ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc)
3138                             == 0);
3139                         vdev_get_stats(vd, vs);
3140                 }
3141         }
3142 }
3143 
3144 static void
3145 spa_add_feature_stats(spa_t *spa, nvlist_t *config)
3146 {
3147         nvlist_t *features;
3148         zap_cursor_t zc;
3149         zap_attribute_t za;
3150 
3151         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3152         VERIFY(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3153 
3154         if (spa->spa_feat_for_read_obj != 0) {
3155                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3156                     spa->spa_feat_for_read_obj);
3157                     zap_cursor_retrieve(&zc, &za) == 0;
3158                     zap_cursor_advance(&zc)) {
3159                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3160                             za.za_num_integers == 1);
3161                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3162                             za.za_first_integer));
3163                 }
3164                 zap_cursor_fini(&zc);
3165         }
3166 
3167         if (spa->spa_feat_for_write_obj != 0) {
3168                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3169                     spa->spa_feat_for_write_obj);
3170                     zap_cursor_retrieve(&zc, &za) == 0;
3171                     zap_cursor_advance(&zc)) {
3172                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3173                             za.za_num_integers == 1);
3174                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3175                             za.za_first_integer));
3176                 }
3177                 zap_cursor_fini(&zc);
3178         }
3179 
3180         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
3181             features) == 0);
3182         nvlist_free(features);
3183 }
3184 
3185 int
3186 spa_get_stats(const char *name, nvlist_t **config,
3187     char *altroot, size_t buflen)
3188 {
3189         int error;
3190         spa_t *spa;
3191 
3192         *config = NULL;
3193         error = spa_open_common(name, &spa, FTAG, NULL, config);
3194 
3195         if (spa != NULL) {
3196                 /*
3197                  * This still leaves a window of inconsistency where the spares
3198                  * or l2cache devices could change and the config would be
3199                  * self-inconsistent.
3200                  */
3201                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3202 
3203                 if (*config != NULL) {
3204                         uint64_t loadtimes[2];
3205 
3206                         loadtimes[0] = spa->spa_loaded_ts.tv_sec;
3207                         loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
3208                         VERIFY(nvlist_add_uint64_array(*config,
3209                             ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2) == 0);
3210 
3211                         VERIFY(nvlist_add_uint64(*config,
3212                             ZPOOL_CONFIG_ERRCOUNT,
3213                             spa_get_errlog_size(spa)) == 0);
3214 
3215                         if (spa_suspended(spa))
3216                                 VERIFY(nvlist_add_uint64(*config,
3217                                     ZPOOL_CONFIG_SUSPENDED,
3218                                     spa->spa_failmode) == 0);
3219 
3220                         spa_add_spares(spa, *config);
3221                         spa_add_l2cache(spa, *config);
3222                         spa_add_feature_stats(spa, *config);
3223                 }
3224         }
3225 
3226         /*
3227          * We want to get the alternate root even for faulted pools, so we cheat
3228          * and call spa_lookup() directly.
3229          */
3230         if (altroot) {
3231                 if (spa == NULL) {
3232                         mutex_enter(&spa_namespace_lock);
3233                         spa = spa_lookup(name);
3234                         if (spa)
3235                                 spa_altroot(spa, altroot, buflen);
3236                         else
3237                                 altroot[0] = '\0';
3238                         spa = NULL;
3239                         mutex_exit(&spa_namespace_lock);
3240                 } else {
3241                         spa_altroot(spa, altroot, buflen);
3242                 }
3243         }
3244 
3245         if (spa != NULL) {
3246                 spa_config_exit(spa, SCL_CONFIG, FTAG);
3247                 spa_close(spa, FTAG);
3248         }
3249 
3250         return (error);
3251 }
3252 
3253 /*
3254  * Validate that the auxiliary device array is well formed.  We must have an
3255  * array of nvlists, each which describes a valid leaf vdev.  If this is an
3256  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
3257  * specified, as long as they are well-formed.
3258  */
3259 static int
3260 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
3261     spa_aux_vdev_t *sav, const char *config, uint64_t version,
3262     vdev_labeltype_t label)
3263 {
3264         nvlist_t **dev;
3265         uint_t i, ndev;
3266         vdev_t *vd;
3267         int error;
3268 
3269         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3270 
3271         /*
3272          * It's acceptable to have no devs specified.
3273          */
3274         if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
3275                 return (0);
3276 
3277         if (ndev == 0)
3278                 return (SET_ERROR(EINVAL));
3279 
3280         /*
3281          * Make sure the pool is formatted with a version that supports this
3282          * device type.
3283          */
3284         if (spa_version(spa) < version)
3285                 return (SET_ERROR(ENOTSUP));
3286 
3287         /*
3288          * Set the pending device list so we correctly handle device in-use
3289          * checking.
3290          */
3291         sav->sav_pending = dev;
3292         sav->sav_npending = ndev;
3293 
3294         for (i = 0; i < ndev; i++) {
3295                 if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
3296                     mode)) != 0)
3297                         goto out;
3298 
3299                 if (!vd->vdev_ops->vdev_op_leaf) {
3300                         vdev_free(vd);
3301                         error = SET_ERROR(EINVAL);
3302                         goto out;
3303                 }
3304 
3305                 /*
3306                  * The L2ARC currently only supports disk devices in
3307                  * kernel context.  For user-level testing, we allow it.
3308                  */
3309 #ifdef _KERNEL
3310                 if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
3311                     strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
3312                         error = SET_ERROR(ENOTBLK);
3313                         vdev_free(vd);
3314                         goto out;
3315                 }
3316 #endif
3317                 vd->vdev_top = vd;
3318 
3319                 if ((error = vdev_open(vd)) == 0 &&
3320                     (error = vdev_label_init(vd, crtxg, label)) == 0) {
3321                         VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
3322                             vd->vdev_guid) == 0);
3323                 }
3324 
3325                 vdev_free(vd);
3326 
3327                 if (error &&
3328                     (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
3329                         goto out;
3330                 else
3331                         error = 0;
3332         }
3333 
3334 out:
3335         sav->sav_pending = NULL;
3336         sav->sav_npending = 0;
3337         return (error);
3338 }
3339 
3340 static int
3341 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
3342 {
3343         int error;
3344 
3345         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3346 
3347         if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3348             &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
3349             VDEV_LABEL_SPARE)) != 0) {
3350                 return (error);
3351         }
3352 
3353         return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3354             &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
3355             VDEV_LABEL_L2CACHE));
3356 }
3357 
3358 static void
3359 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
3360     const char *config)
3361 {
3362         int i;
3363 
3364         if (sav->sav_config != NULL) {
3365                 nvlist_t **olddevs;
3366                 uint_t oldndevs;
3367                 nvlist_t **newdevs;
3368 
3369                 /*
3370                  * Generate new dev list by concatentating with the
3371                  * current dev list.
3372                  */
3373                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
3374                     &olddevs, &oldndevs) == 0);
3375 
3376                 newdevs = kmem_alloc(sizeof (void *) *
3377                     (ndevs + oldndevs), KM_SLEEP);
3378                 for (i = 0; i < oldndevs; i++)
3379                         VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
3380                             KM_SLEEP) == 0);
3381                 for (i = 0; i < ndevs; i++)
3382                         VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
3383                             KM_SLEEP) == 0);
3384 
3385                 VERIFY(nvlist_remove(sav->sav_config, config,
3386                     DATA_TYPE_NVLIST_ARRAY) == 0);
3387 
3388                 VERIFY(nvlist_add_nvlist_array(sav->sav_config,
3389                     config, newdevs, ndevs + oldndevs) == 0);
3390                 for (i = 0; i < oldndevs + ndevs; i++)
3391                         nvlist_free(newdevs[i]);
3392                 kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
3393         } else {
3394                 /*
3395                  * Generate a new dev list.
3396                  */
3397                 VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
3398                     KM_SLEEP) == 0);
3399                 VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
3400                     devs, ndevs) == 0);
3401         }
3402 }
3403 
3404 /*
3405  * Stop and drop level 2 ARC devices
3406  */
3407 void
3408 spa_l2cache_drop(spa_t *spa)
3409 {
3410         vdev_t *vd;
3411         int i;
3412         spa_aux_vdev_t *sav = &spa->spa_l2cache;
3413 
3414         for (i = 0; i < sav->sav_count; i++) {
3415                 uint64_t pool;
3416 
3417                 vd = sav->sav_vdevs[i];
3418                 ASSERT(vd != NULL);
3419 
3420                 if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
3421                     pool != 0ULL && l2arc_vdev_present(vd))
3422                         l2arc_remove_vdev(vd);
3423         }
3424 }
3425 
3426 /*
3427  * Pool Creation
3428  */
3429 int
3430 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
3431     nvlist_t *zplprops)
3432 {
3433         spa_t *spa;
3434         char *altroot = NULL;
3435         vdev_t *rvd;
3436         dsl_pool_t *dp;
3437         dmu_tx_t *tx;
3438         int error = 0;
3439         uint64_t txg = TXG_INITIAL;
3440         nvlist_t **spares, **l2cache;
3441         uint_t nspares, nl2cache;
3442         uint64_t version, obj;
3443         boolean_t has_features;
3444 
3445         /*
3446          * If this pool already exists, return failure.
3447          */
3448         mutex_enter(&spa_namespace_lock);
3449         if (spa_lookup(pool) != NULL) {
3450                 mutex_exit(&spa_namespace_lock);
3451                 return (SET_ERROR(EEXIST));
3452         }
3453 
3454         /*
3455          * Allocate a new spa_t structure.
3456          */
3457         (void) nvlist_lookup_string(props,
3458             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3459         spa = spa_add(pool, NULL, altroot);
3460         spa_activate(spa, spa_mode_global);
3461 
3462         if (props && (error = spa_prop_validate(spa, props))) {
3463                 spa_deactivate(spa);
3464                 spa_remove(spa);
3465                 mutex_exit(&spa_namespace_lock);
3466                 return (error);
3467         }
3468 
3469         has_features = B_FALSE;
3470         for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
3471             elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
3472                 if (zpool_prop_feature(nvpair_name(elem)))
3473                         has_features = B_TRUE;
3474         }
3475 
3476         if (has_features || nvlist_lookup_uint64(props,
3477             zpool_prop_to_name(ZPOOL_PROP_VERSION), &version) != 0) {
3478                 version = SPA_VERSION;
3479         }
3480         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
3481 
3482         spa->spa_first_txg = txg;
3483         spa->spa_uberblock.ub_txg = txg - 1;
3484         spa->spa_uberblock.ub_version = version;
3485         spa->spa_ubsync = spa->spa_uberblock;
3486 
3487         /*
3488          * Create "The Godfather" zio to hold all async IOs
3489          */
3490         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
3491             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
3492 
3493         /*
3494          * Create the root vdev.
3495          */
3496         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3497 
3498         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
3499 
3500         ASSERT(error != 0 || rvd != NULL);
3501         ASSERT(error != 0 || spa->spa_root_vdev == rvd);
3502 
3503         if (error == 0 && !zfs_allocatable_devs(nvroot))
3504                 error = SET_ERROR(EINVAL);
3505 
3506         if (error == 0 &&
3507             (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
3508             (error = spa_validate_aux(spa, nvroot, txg,
3509             VDEV_ALLOC_ADD)) == 0) {
3510                 for (int c = 0; c < rvd->vdev_children; c++) {
3511                         vdev_metaslab_set_size(rvd->vdev_child[c]);
3512                         vdev_expand(rvd->vdev_child[c], txg);
3513                 }
3514         }
3515 
3516         spa_config_exit(spa, SCL_ALL, FTAG);
3517 
3518         if (error != 0) {
3519                 spa_unload(spa);
3520                 spa_deactivate(spa);
3521                 spa_remove(spa);
3522                 mutex_exit(&spa_namespace_lock);
3523                 return (error);
3524         }
3525 
3526         /*
3527          * Get the list of spares, if specified.
3528          */
3529         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3530             &spares, &nspares) == 0) {
3531                 VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
3532                     KM_SLEEP) == 0);
3533                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3534                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3535                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3536                 spa_load_spares(spa);
3537                 spa_config_exit(spa, SCL_ALL, FTAG);
3538                 spa->spa_spares.sav_sync = B_TRUE;
3539         }
3540 
3541         /*
3542          * Get the list of level 2 cache devices, if specified.
3543          */
3544         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3545             &l2cache, &nl2cache) == 0) {
3546                 VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3547                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
3548                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3549                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3550                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3551                 spa_load_l2cache(spa);
3552                 spa_config_exit(spa, SCL_ALL, FTAG);
3553                 spa->spa_l2cache.sav_sync = B_TRUE;
3554         }
3555 
3556         spa->spa_is_initializing = B_TRUE;
3557         spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
3558         spa->spa_meta_objset = dp->dp_meta_objset;
3559         spa->spa_is_initializing = B_FALSE;
3560 
3561         /*
3562          * Create DDTs (dedup tables).
3563          */
3564         ddt_create(spa);
3565 
3566         spa_update_dspace(spa);
3567 
3568         tx = dmu_tx_create_assigned(dp, txg);
3569 
3570         /*
3571          * Create the pool config object.
3572          */
3573         spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
3574             DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
3575             DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
3576 
3577         if (zap_add(spa->spa_meta_objset,
3578             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
3579             sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
3580                 cmn_err(CE_PANIC, "failed to add pool config");
3581         }
3582 
3583         if (spa_version(spa) >= SPA_VERSION_FEATURES)
3584                 spa_feature_create_zap_objects(spa, tx);
3585 
3586         if (zap_add(spa->spa_meta_objset,
3587             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
3588             sizeof (uint64_t), 1, &version, tx) != 0) {
3589                 cmn_err(CE_PANIC, "failed to add pool version");
3590         }
3591 
3592         /* Newly created pools with the right version are always deflated. */
3593         if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
3594                 spa->spa_deflate = TRUE;
3595                 if (zap_add(spa->spa_meta_objset,
3596                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
3597                     sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
3598                         cmn_err(CE_PANIC, "failed to add deflate");
3599                 }
3600         }
3601 
3602         /*
3603          * Create the deferred-free bpobj.  Turn off compression
3604          * because sync-to-convergence takes longer if the blocksize
3605          * keeps changing.
3606          */
3607         obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
3608         dmu_object_set_compress(spa->spa_meta_objset, obj,
3609             ZIO_COMPRESS_OFF, tx);
3610         if (zap_add(spa->spa_meta_objset,
3611             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
3612             sizeof (uint64_t), 1, &obj, tx) != 0) {
3613                 cmn_err(CE_PANIC, "failed to add bpobj");
3614         }
3615         VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
3616             spa->spa_meta_objset, obj));
3617 
3618         /*
3619          * Create the pool's history object.
3620          */
3621         if (version >= SPA_VERSION_ZPOOL_HISTORY)
3622                 spa_history_create_obj(spa, tx);
3623 
3624         /*
3625          * Set pool properties.
3626          */
3627         spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
3628         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
3629         spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
3630         spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
3631 
3632         if (props != NULL) {
3633                 spa_configfile_set(spa, props, B_FALSE);
3634                 spa_sync_props(props, tx);
3635         }
3636 
3637         dmu_tx_commit(tx);
3638 
3639         spa->spa_sync_on = B_TRUE;
3640         txg_sync_start(spa->spa_dsl_pool);
3641 
3642         /*
3643          * We explicitly wait for the first transaction to complete so that our
3644          * bean counters are appropriately updated.
3645          */
3646         txg_wait_synced(spa->spa_dsl_pool, txg);
3647 
3648         spa_config_sync(spa, B_FALSE, B_TRUE);
3649 
3650         spa_history_log_version(spa, "create");
3651 
3652         spa->spa_minref = refcount_count(&spa->spa_refcount);
3653 
3654         mutex_exit(&spa_namespace_lock);
3655 
3656         return (0);
3657 }
3658 
3659 #ifdef _KERNEL
3660 /*
3661  * Get the root pool information from the root disk, then import the root pool
3662  * during the system boot up time.
3663  */
3664 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
3665 
3666 static nvlist_t *
3667 spa_generate_rootconf(char *devpath, char *devid, uint64_t *guid)
3668 {
3669         nvlist_t *config;
3670         nvlist_t *nvtop, *nvroot;
3671         uint64_t pgid;
3672 
3673         if (vdev_disk_read_rootlabel(devpath, devid, &config) != 0)
3674                 return (NULL);
3675 
3676         /*
3677          * Add this top-level vdev to the child array.
3678          */
3679         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3680             &nvtop) == 0);
3681         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
3682             &pgid) == 0);
3683         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, guid) == 0);
3684 
3685         /*
3686          * Put this pool's top-level vdevs into a root vdev.
3687          */
3688         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3689         VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
3690             VDEV_TYPE_ROOT) == 0);
3691         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
3692         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
3693         VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
3694             &nvtop, 1) == 0);
3695 
3696         /*
3697          * Replace the existing vdev_tree with the new root vdev in
3698          * this pool's configuration (remove the old, add the new).
3699          */
3700         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
3701         nvlist_free(nvroot);
3702         return (config);
3703 }
3704 
3705 /*
3706  * Walk the vdev tree and see if we can find a device with "better"
3707  * configuration. A configuration is "better" if the label on that
3708  * device has a more recent txg.
3709  */
3710 static void
3711 spa_alt_rootvdev(vdev_t *vd, vdev_t **avd, uint64_t *txg)
3712 {
3713         for (int c = 0; c < vd->vdev_children; c++)
3714                 spa_alt_rootvdev(vd->vdev_child[c], avd, txg);
3715 
3716         if (vd->vdev_ops->vdev_op_leaf) {
3717                 nvlist_t *label;
3718                 uint64_t label_txg;
3719 
3720                 if (vdev_disk_read_rootlabel(vd->vdev_physpath, vd->vdev_devid,
3721                     &label) != 0)
3722                         return;
3723 
3724                 VERIFY(nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
3725                     &label_txg) == 0);
3726 
3727                 /*
3728                  * Do we have a better boot device?
3729                  */
3730                 if (label_txg > *txg) {
3731                         *txg = label_txg;
3732                         *avd = vd;
3733                 }
3734                 nvlist_free(label);
3735         }
3736 }
3737 
3738 /*
3739  * Import a root pool.
3740  *
3741  * For x86. devpath_list will consist of devid and/or physpath name of
3742  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
3743  * The GRUB "findroot" command will return the vdev we should boot.
3744  *
3745  * For Sparc, devpath_list consists the physpath name of the booting device
3746  * no matter the rootpool is a single device pool or a mirrored pool.
3747  * e.g.
3748  *      "/pci@1f,0/ide@d/disk@0,0:a"
3749  */
3750 int
3751 spa_import_rootpool(char *devpath, char *devid)
3752 {
3753         spa_t *spa;
3754         vdev_t *rvd, *bvd, *avd = NULL;
3755         nvlist_t *config, *nvtop;
3756         uint64_t guid, txg;
3757         char *pname;
3758         int error;
3759 
3760         /*
3761          * Read the label from the boot device and generate a configuration.
3762          */
3763         config = spa_generate_rootconf(devpath, devid, &guid);
3764 #if defined(_OBP) && defined(_KERNEL)
3765         if (config == NULL) {
3766                 if (strstr(devpath, "/iscsi/ssd") != NULL) {
3767                         /* iscsi boot */
3768                         get_iscsi_bootpath_phy(devpath);
3769                         config = spa_generate_rootconf(devpath, devid, &guid);
3770                 }
3771         }
3772 #endif
3773         if (config == NULL) {
3774                 cmn_err(CE_NOTE, "Cannot read the pool label from '%s'",
3775                     devpath);
3776                 return (SET_ERROR(EIO));
3777         }
3778 
3779         VERIFY(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
3780             &pname) == 0);
3781         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
3782 
3783         mutex_enter(&spa_namespace_lock);
3784         if ((spa = spa_lookup(pname)) != NULL) {
3785                 /*
3786                  * Remove the existing root pool from the namespace so that we
3787                  * can replace it with the correct config we just read in.
3788                  */
3789                 spa_remove(spa);
3790         }
3791 
3792         spa = spa_add(pname, config, NULL);
3793         spa->spa_is_root = B_TRUE;
3794         spa->spa_import_flags = ZFS_IMPORT_VERBATIM;
3795 
3796         /*
3797          * Build up a vdev tree based on the boot device's label config.
3798          */
3799         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3800             &nvtop) == 0);
3801         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3802         error = spa_config_parse(spa, &rvd, nvtop, NULL, 0,
3803             VDEV_ALLOC_ROOTPOOL);
3804         spa_config_exit(spa, SCL_ALL, FTAG);
3805         if (error) {
3806                 mutex_exit(&spa_namespace_lock);
3807                 nvlist_free(config);
3808                 cmn_err(CE_NOTE, "Can not parse the config for pool '%s'",
3809                     pname);
3810                 return (error);
3811         }
3812 
3813         /*
3814          * Get the boot vdev.
3815          */
3816         if ((bvd = vdev_lookup_by_guid(rvd, guid)) == NULL) {
3817                 cmn_err(CE_NOTE, "Can not find the boot vdev for guid %llu",
3818                     (u_longlong_t)guid);
3819                 error = SET_ERROR(ENOENT);
3820                 goto out;
3821         }
3822 
3823         /*
3824          * Determine if there is a better boot device.
3825          */
3826         avd = bvd;
3827         spa_alt_rootvdev(rvd, &avd, &txg);
3828         if (avd != bvd) {
3829                 cmn_err(CE_NOTE, "The boot device is 'degraded'. Please "
3830                     "try booting from '%s'", avd->vdev_path);
3831                 error = SET_ERROR(EINVAL);
3832                 goto out;
3833         }
3834 
3835         /*
3836          * If the boot device is part of a spare vdev then ensure that
3837          * we're booting off the active spare.
3838          */
3839         if (bvd->vdev_parent->vdev_ops == &vdev_spare_ops &&
3840             !bvd->vdev_isspare) {
3841                 cmn_err(CE_NOTE, "The boot device is currently spared. Please "
3842                     "try booting from '%s'",
3843                     bvd->vdev_parent->
3844                     vdev_child[bvd->vdev_parent->vdev_children - 1]->vdev_path);
3845                 error = SET_ERROR(EINVAL);
3846                 goto out;
3847         }
3848 
3849         error = 0;
3850 out:
3851         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3852         vdev_free(rvd);
3853         spa_config_exit(spa, SCL_ALL, FTAG);
3854         mutex_exit(&spa_namespace_lock);
3855 
3856         nvlist_free(config);
3857         return (error);
3858 }
3859 
3860 #endif
3861 
3862 /*
3863  * Import a non-root pool into the system.
3864  */
3865 int
3866 spa_import(const char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
3867 {
3868         spa_t *spa;
3869         char *altroot = NULL;
3870         spa_load_state_t state = SPA_LOAD_IMPORT;
3871         zpool_rewind_policy_t policy;
3872         uint64_t mode = spa_mode_global;
3873         uint64_t readonly = B_FALSE;
3874         int error;
3875         nvlist_t *nvroot;
3876         nvlist_t **spares, **l2cache;
3877         uint_t nspares, nl2cache;
3878 
3879         /*
3880          * If a pool with this name exists, return failure.
3881          */
3882         mutex_enter(&spa_namespace_lock);
3883         if (spa_lookup(pool) != NULL) {
3884                 mutex_exit(&spa_namespace_lock);
3885                 return (SET_ERROR(EEXIST));
3886         }
3887 
3888         /*
3889          * Create and initialize the spa structure.
3890          */
3891         (void) nvlist_lookup_string(props,
3892             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3893         (void) nvlist_lookup_uint64(props,
3894             zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
3895         if (readonly)
3896                 mode = FREAD;
3897         spa = spa_add(pool, config, altroot);
3898         spa->spa_import_flags = flags;
3899 
3900         /*
3901          * Verbatim import - Take a pool and insert it into the namespace
3902          * as if it had been loaded at boot.
3903          */
3904         if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
3905                 if (props != NULL)
3906                         spa_configfile_set(spa, props, B_FALSE);
3907 
3908                 spa_config_sync(spa, B_FALSE, B_TRUE);
3909 
3910                 mutex_exit(&spa_namespace_lock);
3911                 return (0);
3912         }
3913 
3914         spa_activate(spa, mode);
3915 
3916         /*
3917          * Don't start async tasks until we know everything is healthy.
3918          */
3919         spa_async_suspend(spa);
3920 
3921         zpool_get_rewind_policy(config, &policy);
3922         if (policy.zrp_request & ZPOOL_DO_REWIND)
3923                 state = SPA_LOAD_RECOVER;
3924 
3925         /*
3926          * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
3927          * because the user-supplied config is actually the one to trust when
3928          * doing an import.
3929          */
3930         if (state != SPA_LOAD_RECOVER)
3931                 spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
3932 
3933         error = spa_load_best(spa, state, B_TRUE, policy.zrp_txg,
3934             policy.zrp_request);
3935 
3936         /*
3937          * Propagate anything learned while loading the pool and pass it
3938          * back to caller (i.e. rewind info, missing devices, etc).
3939          */
3940         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
3941             spa->spa_load_info) == 0);
3942 
3943         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3944         /*
3945          * Toss any existing sparelist, as it doesn't have any validity
3946          * anymore, and conflicts with spa_has_spare().
3947          */
3948         if (spa->spa_spares.sav_config) {
3949                 nvlist_free(spa->spa_spares.sav_config);
3950                 spa->spa_spares.sav_config = NULL;
3951                 spa_load_spares(spa);
3952         }
3953         if (spa->spa_l2cache.sav_config) {
3954                 nvlist_free(spa->spa_l2cache.sav_config);
3955                 spa->spa_l2cache.sav_config = NULL;
3956                 spa_load_l2cache(spa);
3957         }
3958 
3959         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3960             &nvroot) == 0);
3961         if (error == 0)
3962                 error = spa_validate_aux(spa, nvroot, -1ULL,
3963                     VDEV_ALLOC_SPARE);
3964         if (error == 0)
3965                 error = spa_validate_aux(spa, nvroot, -1ULL,
3966                     VDEV_ALLOC_L2CACHE);
3967         spa_config_exit(spa, SCL_ALL, FTAG);
3968 
3969         if (props != NULL)
3970                 spa_configfile_set(spa, props, B_FALSE);
3971 
3972         if (error != 0 || (props && spa_writeable(spa) &&
3973             (error = spa_prop_set(spa, props)))) {
3974                 spa_unload(spa);
3975                 spa_deactivate(spa);
3976                 spa_remove(spa);
3977                 mutex_exit(&spa_namespace_lock);
3978                 return (error);
3979         }
3980 
3981         spa_async_resume(spa);
3982 
3983         /*
3984          * Override any spares and level 2 cache devices as specified by
3985          * the user, as these may have correct device names/devids, etc.
3986          */
3987         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3988             &spares, &nspares) == 0) {
3989                 if (spa->spa_spares.sav_config)
3990                         VERIFY(nvlist_remove(spa->spa_spares.sav_config,
3991                             ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
3992                 else
3993                         VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
3994                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
3995                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3996                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3997                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3998                 spa_load_spares(spa);
3999                 spa_config_exit(spa, SCL_ALL, FTAG);
4000                 spa->spa_spares.sav_sync = B_TRUE;
4001         }
4002         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
4003             &l2cache, &nl2cache) == 0) {
4004                 if (spa->spa_l2cache.sav_config)
4005                         VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
4006                             ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
4007                 else
4008                         VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
4009                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
4010                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
4011                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
4012                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4013                 spa_load_l2cache(spa);
4014                 spa_config_exit(spa, SCL_ALL, FTAG);
4015                 spa->spa_l2cache.sav_sync = B_TRUE;
4016         }
4017 
4018         /*
4019          * Check for any removed devices.
4020          */
4021         if (spa->spa_autoreplace) {
4022                 spa_aux_check_removed(&spa->spa_spares);
4023                 spa_aux_check_removed(&spa->spa_l2cache);
4024         }
4025 
4026         if (spa_writeable(spa)) {
4027                 /*
4028                  * Update the config cache to include the newly-imported pool.
4029                  */
4030                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4031         }
4032 
4033         /*
4034          * It's possible that the pool was expanded while it was exported.
4035          * We kick off an async task to handle this for us.
4036          */
4037         spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
4038 
4039         mutex_exit(&spa_namespace_lock);
4040         spa_history_log_version(spa, "import");
4041 
4042         return (0);
4043 }
4044 
4045 nvlist_t *
4046 spa_tryimport(nvlist_t *tryconfig)
4047 {
4048         nvlist_t *config = NULL;
4049         char *poolname;
4050         spa_t *spa;
4051         uint64_t state;
4052         int error;
4053 
4054         if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
4055                 return (NULL);
4056 
4057         if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
4058                 return (NULL);
4059 
4060         /*
4061          * Create and initialize the spa structure.
4062          */
4063         mutex_enter(&spa_namespace_lock);
4064         spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
4065         spa_activate(spa, FREAD);
4066 
4067         /*
4068          * Pass off the heavy lifting to spa_load().
4069          * Pass TRUE for mosconfig because the user-supplied config
4070          * is actually the one to trust when doing an import.
4071          */
4072         error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING, B_TRUE);
4073 
4074         /*
4075          * If 'tryconfig' was at least parsable, return the current config.
4076          */
4077         if (spa->spa_root_vdev != NULL) {
4078                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
4079                 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
4080                     poolname) == 0);
4081                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4082                     state) == 0);
4083                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
4084                     spa->spa_uberblock.ub_timestamp) == 0);
4085                 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
4086                     spa->spa_load_info) == 0);
4087 
4088                 /*
4089                  * If the bootfs property exists on this pool then we
4090                  * copy it out so that external consumers can tell which
4091                  * pools are bootable.
4092                  */
4093                 if ((!error || error == EEXIST) && spa->spa_bootfs) {
4094                         char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4095 
4096                         /*
4097                          * We have to play games with the name since the
4098                          * pool was opened as TRYIMPORT_NAME.
4099                          */
4100                         if (dsl_dsobj_to_dsname(spa_name(spa),
4101                             spa->spa_bootfs, tmpname) == 0) {
4102                                 char *cp;
4103                                 char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4104 
4105                                 cp = strchr(tmpname, '/');
4106                                 if (cp == NULL) {
4107                                         (void) strlcpy(dsname, tmpname,
4108                                             MAXPATHLEN);
4109                                 } else {
4110                                         (void) snprintf(dsname, MAXPATHLEN,
4111                                             "%s/%s", poolname, ++cp);
4112                                 }
4113                                 VERIFY(nvlist_add_string(config,
4114                                     ZPOOL_CONFIG_BOOTFS, dsname) == 0);
4115                                 kmem_free(dsname, MAXPATHLEN);
4116                         }
4117                         kmem_free(tmpname, MAXPATHLEN);
4118                 }
4119 
4120                 /*
4121                  * Add the list of hot spares and level 2 cache devices.
4122                  */
4123                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
4124                 spa_add_spares(spa, config);
4125                 spa_add_l2cache(spa, config);
4126                 spa_config_exit(spa, SCL_CONFIG, FTAG);
4127         }
4128 
4129         spa_unload(spa);
4130         spa_deactivate(spa);
4131         spa_remove(spa);
4132         mutex_exit(&spa_namespace_lock);
4133 
4134         return (config);
4135 }
4136 
4137 /*
4138  * Pool export/destroy
4139  *
4140  * The act of destroying or exporting a pool is very simple.  We make sure there
4141  * is no more pending I/O and any references to the pool are gone.  Then, we
4142  * update the pool state and sync all the labels to disk, removing the
4143  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
4144  * we don't sync the labels or remove the configuration cache.
4145  */
4146 static int
4147 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
4148     boolean_t force, boolean_t hardforce)
4149 {
4150         spa_t *spa;
4151 
4152         if (oldconfig)
4153                 *oldconfig = NULL;
4154 
4155         if (!(spa_mode_global & FWRITE))
4156                 return (SET_ERROR(EROFS));
4157 
4158         mutex_enter(&spa_namespace_lock);
4159         if ((spa = spa_lookup(pool)) == NULL) {
4160                 mutex_exit(&spa_namespace_lock);
4161                 return (SET_ERROR(ENOENT));
4162         }
4163 
4164         /*
4165          * Put a hold on the pool, drop the namespace lock, stop async tasks,
4166          * reacquire the namespace lock, and see if we can export.
4167          */
4168         spa_open_ref(spa, FTAG);
4169         mutex_exit(&spa_namespace_lock);
4170         spa_async_suspend(spa);
4171         mutex_enter(&spa_namespace_lock);
4172         spa_close(spa, FTAG);
4173 
4174         /*
4175          * The pool will be in core if it's openable,
4176          * in which case we can modify its state.
4177          */
4178         if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
4179                 /*
4180                  * Objsets may be open only because they're dirty, so we
4181                  * have to force it to sync before checking spa_refcnt.
4182                  */
4183                 txg_wait_synced(spa->spa_dsl_pool, 0);
4184 
4185                 /*
4186                  * A pool cannot be exported or destroyed if there are active
4187                  * references.  If we are resetting a pool, allow references by
4188                  * fault injection handlers.
4189                  */
4190                 if (!spa_refcount_zero(spa) ||
4191                     (spa->spa_inject_ref != 0 &&
4192                     new_state != POOL_STATE_UNINITIALIZED)) {
4193                         spa_async_resume(spa);
4194                         mutex_exit(&spa_namespace_lock);
4195                         return (SET_ERROR(EBUSY));
4196                 }
4197 
4198                 /*
4199                  * A pool cannot be exported if it has an active shared spare.
4200                  * This is to prevent other pools stealing the active spare
4201                  * from an exported pool. At user's own will, such pool can
4202                  * be forcedly exported.
4203                  */
4204                 if (!force && new_state == POOL_STATE_EXPORTED &&
4205                     spa_has_active_shared_spare(spa)) {
4206                         spa_async_resume(spa);
4207                         mutex_exit(&spa_namespace_lock);
4208                         return (SET_ERROR(EXDEV));
4209                 }
4210 
4211                 /*
4212                  * We want this to be reflected on every label,
4213                  * so mark them all dirty.  spa_unload() will do the
4214                  * final sync that pushes these changes out.
4215                  */
4216                 if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
4217                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4218                         spa->spa_state = new_state;
4219                         spa->spa_final_txg = spa_last_synced_txg(spa) +
4220                             TXG_DEFER_SIZE + 1;
4221                         vdev_config_dirty(spa->spa_root_vdev);
4222                         spa_config_exit(spa, SCL_ALL, FTAG);
4223                 }
4224         }
4225 
4226         spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
4227 
4228         if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
4229                 spa_unload(spa);
4230                 spa_deactivate(spa);
4231         }
4232 
4233         if (oldconfig && spa->spa_config)
4234                 VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
4235 
4236         if (new_state != POOL_STATE_UNINITIALIZED) {
4237                 if (!hardforce)
4238                         spa_config_sync(spa, B_TRUE, B_TRUE);
4239                 spa_remove(spa);
4240         }
4241         mutex_exit(&spa_namespace_lock);
4242 
4243         return (0);
4244 }
4245 
4246 /*
4247  * Destroy a storage pool.
4248  */
4249 int
4250 spa_destroy(char *pool)
4251 {
4252         return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
4253             B_FALSE, B_FALSE));
4254 }
4255 
4256 /*
4257  * Export a storage pool.
4258  */
4259 int
4260 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
4261     boolean_t hardforce)
4262 {
4263         return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
4264             force, hardforce));
4265 }
4266 
4267 /*
4268  * Similar to spa_export(), this unloads the spa_t without actually removing it
4269  * from the namespace in any way.
4270  */
4271 int
4272 spa_reset(char *pool)
4273 {
4274         return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
4275             B_FALSE, B_FALSE));
4276 }
4277 
4278 /*
4279  * ==========================================================================
4280  * Device manipulation
4281  * ==========================================================================
4282  */
4283 
4284 /*
4285  * Add a device to a storage pool.
4286  */
4287 int
4288 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
4289 {
4290         uint64_t txg, id;
4291         int error;
4292         vdev_t *rvd = spa->spa_root_vdev;
4293         vdev_t *vd, *tvd;
4294         nvlist_t **spares, **l2cache;
4295         uint_t nspares, nl2cache;
4296 
4297         ASSERT(spa_writeable(spa));
4298 
4299         txg = spa_vdev_enter(spa);
4300 
4301         if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
4302             VDEV_ALLOC_ADD)) != 0)
4303                 return (spa_vdev_exit(spa, NULL, txg, error));
4304 
4305         spa->spa_pending_vdev = vd;  /* spa_vdev_exit() will clear this */
4306 
4307         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
4308             &nspares) != 0)
4309                 nspares = 0;
4310 
4311         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
4312             &nl2cache) != 0)
4313                 nl2cache = 0;
4314 
4315         if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
4316                 return (spa_vdev_exit(spa, vd, txg, EINVAL));
4317 
4318         if (vd->vdev_children != 0 &&
4319             (error = vdev_create(vd, txg, B_FALSE)) != 0)
4320                 return (spa_vdev_exit(spa, vd, txg, error));
4321 
4322         /*
4323          * We must validate the spares and l2cache devices after checking the
4324          * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
4325          */
4326         if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
4327                 return (spa_vdev_exit(spa, vd, txg, error));
4328 
4329         /*
4330          * Transfer each new top-level vdev from vd to rvd.
4331          */
4332         for (int c = 0; c < vd->vdev_children; c++) {
4333 
4334                 /*
4335                  * Set the vdev id to the first hole, if one exists.
4336                  */
4337                 for (id = 0; id < rvd->vdev_children; id++) {
4338                         if (rvd->vdev_child[id]->vdev_ishole) {
4339                                 vdev_free(rvd->vdev_child[id]);
4340                                 break;
4341                         }
4342                 }
4343                 tvd = vd->vdev_child[c];
4344                 vdev_remove_child(vd, tvd);
4345                 tvd->vdev_id = id;
4346                 vdev_add_child(rvd, tvd);
4347                 vdev_config_dirty(tvd);
4348         }
4349 
4350         if (nspares != 0) {
4351                 spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
4352                     ZPOOL_CONFIG_SPARES);
4353                 spa_load_spares(spa);
4354                 spa->spa_spares.sav_sync = B_TRUE;
4355         }
4356 
4357         if (nl2cache != 0) {
4358                 spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
4359                     ZPOOL_CONFIG_L2CACHE);
4360                 spa_load_l2cache(spa);
4361                 spa->spa_l2cache.sav_sync = B_TRUE;
4362         }
4363 
4364         /*
4365          * We have to be careful when adding new vdevs to an existing pool.
4366          * If other threads start allocating from these vdevs before we
4367          * sync the config cache, and we lose power, then upon reboot we may
4368          * fail to open the pool because there are DVAs that the config cache
4369          * can't translate.  Therefore, we first add the vdevs without
4370          * initializing metaslabs; sync the config cache (via spa_vdev_exit());
4371          * and then let spa_config_update() initialize the new metaslabs.
4372          *
4373          * spa_load() checks for added-but-not-initialized vdevs, so that
4374          * if we lose power at any point in this sequence, the remaining
4375          * steps will be completed the next time we load the pool.
4376          */
4377         (void) spa_vdev_exit(spa, vd, txg, 0);
4378 
4379         mutex_enter(&spa_namespace_lock);
4380         spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4381         mutex_exit(&spa_namespace_lock);
4382 
4383         return (0);
4384 }
4385 
4386 /*
4387  * Attach a device to a mirror.  The arguments are the path to any device
4388  * in the mirror, and the nvroot for the new device.  If the path specifies
4389  * a device that is not mirrored, we automatically insert the mirror vdev.
4390  *
4391  * If 'replacing' is specified, the new device is intended to replace the
4392  * existing device; in this case the two devices are made into their own
4393  * mirror using the 'replacing' vdev, which is functionally identical to
4394  * the mirror vdev (it actually reuses all the same ops) but has a few
4395  * extra rules: you can't attach to it after it's been created, and upon
4396  * completion of resilvering, the first disk (the one being replaced)
4397  * is automatically detached.
4398  */
4399 int
4400 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
4401 {
4402         uint64_t txg, dtl_max_txg;
4403         vdev_t *rvd = spa->spa_root_vdev;
4404         vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
4405         vdev_ops_t *pvops;
4406         char *oldvdpath, *newvdpath;
4407         int newvd_isspare;
4408         int error;
4409 
4410         ASSERT(spa_writeable(spa));
4411 
4412         txg = spa_vdev_enter(spa);
4413 
4414         oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
4415 
4416         if (oldvd == NULL)
4417                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4418 
4419         if (!oldvd->vdev_ops->vdev_op_leaf)
4420                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4421 
4422         pvd = oldvd->vdev_parent;
4423 
4424         if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
4425             VDEV_ALLOC_ATTACH)) != 0)
4426                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4427 
4428         if (newrootvd->vdev_children != 1)
4429                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4430 
4431         newvd = newrootvd->vdev_child[0];
4432 
4433         if (!newvd->vdev_ops->vdev_op_leaf)
4434                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4435 
4436         if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
4437                 return (spa_vdev_exit(spa, newrootvd, txg, error));
4438 
4439         /*
4440          * Spares can't replace logs
4441          */
4442         if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
4443                 return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4444 
4445         if (!replacing) {
4446                 /*
4447                  * For attach, the only allowable parent is a mirror or the root
4448                  * vdev.
4449                  */
4450                 if (pvd->vdev_ops != &vdev_mirror_ops &&
4451                     pvd->vdev_ops != &vdev_root_ops)
4452                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4453 
4454                 pvops = &vdev_mirror_ops;
4455         } else {
4456                 /*
4457                  * Active hot spares can only be replaced by inactive hot
4458                  * spares.
4459                  */
4460                 if (pvd->vdev_ops == &vdev_spare_ops &&
4461                     oldvd->vdev_isspare &&
4462                     !spa_has_spare(spa, newvd->vdev_guid))
4463                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4464 
4465                 /*
4466                  * If the source is a hot spare, and the parent isn't already a
4467                  * spare, then we want to create a new hot spare.  Otherwise, we
4468                  * want to create a replacing vdev.  The user is not allowed to
4469                  * attach to a spared vdev child unless the 'isspare' state is
4470                  * the same (spare replaces spare, non-spare replaces
4471                  * non-spare).
4472                  */
4473                 if (pvd->vdev_ops == &vdev_replacing_ops &&
4474                     spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
4475                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4476                 } else if (pvd->vdev_ops == &vdev_spare_ops &&
4477                     newvd->vdev_isspare != oldvd->vdev_isspare) {
4478                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4479                 }
4480 
4481                 if (newvd->vdev_isspare)
4482                         pvops = &vdev_spare_ops;
4483                 else
4484                         pvops = &vdev_replacing_ops;
4485         }
4486 
4487         /*
4488          * Make sure the new device is big enough.
4489          */
4490         if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
4491                 return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
4492 
4493         /*
4494          * The new device cannot have a higher alignment requirement
4495          * than the top-level vdev.
4496          */
4497         if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
4498                 return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
4499 
4500         /*
4501          * If this is an in-place replacement, update oldvd's path and devid
4502          * to make it distinguishable from newvd, and unopenable from now on.
4503          */
4504         if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
4505                 spa_strfree(oldvd->vdev_path);
4506                 oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
4507                     KM_SLEEP);
4508                 (void) sprintf(oldvd->vdev_path, "%s/%s",
4509                     newvd->vdev_path, "old");
4510                 if (oldvd->vdev_devid != NULL) {
4511                         spa_strfree(oldvd->vdev_devid);
4512                         oldvd->vdev_devid = NULL;
4513                 }
4514         }
4515 
4516         /* mark the device being resilvered */
4517         newvd->vdev_resilver_txg = txg;
4518 
4519         /*
4520          * If the parent is not a mirror, or if we're replacing, insert the new
4521          * mirror/replacing/spare vdev above oldvd.
4522          */
4523         if (pvd->vdev_ops != pvops)
4524                 pvd = vdev_add_parent(oldvd, pvops);
4525 
4526         ASSERT(pvd->vdev_top->vdev_parent == rvd);
4527         ASSERT(pvd->vdev_ops == pvops);
4528         ASSERT(oldvd->vdev_parent == pvd);
4529 
4530         /*
4531          * Extract the new device from its root and add it to pvd.
4532          */
4533         vdev_remove_child(newrootvd, newvd);
4534         newvd->vdev_id = pvd->vdev_children;
4535         newvd->vdev_crtxg = oldvd->vdev_crtxg;
4536         vdev_add_child(pvd, newvd);
4537 
4538         tvd = newvd->vdev_top;
4539         ASSERT(pvd->vdev_top == tvd);
4540         ASSERT(tvd->vdev_parent == rvd);
4541 
4542         vdev_config_dirty(tvd);
4543 
4544         /*
4545          * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
4546          * for any dmu_sync-ed blocks.  It will propagate upward when
4547          * spa_vdev_exit() calls vdev_dtl_reassess().
4548          */
4549         dtl_max_txg = txg + TXG_CONCURRENT_STATES;
4550 
4551         vdev_dtl_dirty(newvd, DTL_MISSING, TXG_INITIAL,
4552             dtl_max_txg - TXG_INITIAL);
4553 
4554         if (newvd->vdev_isspare) {
4555                 spa_spare_activate(newvd);
4556                 spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
4557         }
4558 
4559         oldvdpath = spa_strdup(oldvd->vdev_path);
4560         newvdpath = spa_strdup(newvd->vdev_path);
4561         newvd_isspare = newvd->vdev_isspare;
4562 
4563         /*
4564          * Mark newvd's DTL dirty in this txg.
4565          */
4566         vdev_dirty(tvd, VDD_DTL, newvd, txg);
4567 
4568         /*
4569          * Schedule the resilver to restart in the future. We do this to
4570          * ensure that dmu_sync-ed blocks have been stitched into the
4571          * respective datasets.
4572          */
4573         dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
4574 
4575         /*
4576          * Commit the config
4577          */
4578         (void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
4579 
4580         spa_history_log_internal(spa, "vdev attach", NULL,
4581             "%s vdev=%s %s vdev=%s",
4582             replacing && newvd_isspare ? "spare in" :
4583             replacing ? "replace" : "attach", newvdpath,
4584             replacing ? "for" : "to", oldvdpath);
4585 
4586         spa_strfree(oldvdpath);
4587         spa_strfree(newvdpath);
4588 
4589         if (spa->spa_bootfs)
4590                 spa_event_notify(spa, newvd, ESC_ZFS_BOOTFS_VDEV_ATTACH);
4591 
4592         return (0);
4593 }
4594 
4595 /*
4596  * Detach a device from a mirror or replacing vdev.
4597  *
4598  * If 'replace_done' is specified, only detach if the parent
4599  * is a replacing vdev.
4600  */
4601 int
4602 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
4603 {
4604         uint64_t txg;
4605         int error;
4606         vdev_t *rvd = spa->spa_root_vdev;
4607         vdev_t *vd, *pvd, *cvd, *tvd;
4608         boolean_t unspare = B_FALSE;
4609         uint64_t unspare_guid = 0;
4610         char *vdpath;
4611 
4612         ASSERT(spa_writeable(spa));
4613 
4614         txg = spa_vdev_enter(spa);
4615 
4616         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4617 
4618         if (vd == NULL)
4619                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4620 
4621         if (!vd->vdev_ops->vdev_op_leaf)
4622                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4623 
4624         pvd = vd->vdev_parent;
4625 
4626         /*
4627          * If the parent/child relationship is not as expected, don't do it.
4628          * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
4629          * vdev that's replacing B with C.  The user's intent in replacing
4630          * is to go from M(A,B) to M(A,C).  If the user decides to cancel
4631          * the replace by detaching C, the expected behavior is to end up
4632          * M(A,B).  But suppose that right after deciding to detach C,
4633          * the replacement of B completes.  We would have M(A,C), and then
4634          * ask to detach C, which would leave us with just A -- not what
4635          * the user wanted.  To prevent this, we make sure that the
4636          * parent/child relationship hasn't changed -- in this example,
4637          * that C's parent is still the replacing vdev R.
4638          */
4639         if (pvd->vdev_guid != pguid && pguid != 0)
4640                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4641 
4642         /*
4643          * Only 'replacing' or 'spare' vdevs can be replaced.
4644          */
4645         if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
4646             pvd->vdev_ops != &vdev_spare_ops)
4647                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4648 
4649         ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
4650             spa_version(spa) >= SPA_VERSION_SPARES);
4651 
4652         /*
4653          * Only mirror, replacing, and spare vdevs support detach.
4654          */
4655         if (pvd->vdev_ops != &vdev_replacing_ops &&
4656             pvd->vdev_ops != &vdev_mirror_ops &&
4657             pvd->vdev_ops != &vdev_spare_ops)
4658                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4659 
4660         /*
4661          * If this device has the only valid copy of some data,
4662          * we cannot safely detach it.
4663          */
4664         if (vdev_dtl_required(vd))
4665                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4666 
4667         ASSERT(pvd->vdev_children >= 2);
4668 
4669         /*
4670          * If we are detaching the second disk from a replacing vdev, then
4671          * check to see if we changed the original vdev's path to have "/old"
4672          * at the end in spa_vdev_attach().  If so, undo that change now.
4673          */
4674         if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
4675             vd->vdev_path != NULL) {
4676                 size_t len = strlen(vd->vdev_path);
4677 
4678                 for (int c = 0; c < pvd->vdev_children; c++) {
4679                         cvd = pvd->vdev_child[c];
4680 
4681                         if (cvd == vd || cvd->vdev_path == NULL)
4682                                 continue;
4683 
4684                         if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
4685                             strcmp(cvd->vdev_path + len, "/old") == 0) {
4686                                 spa_strfree(cvd->vdev_path);
4687                                 cvd->vdev_path = spa_strdup(vd->vdev_path);
4688                                 break;
4689                         }
4690                 }
4691         }
4692 
4693         /*
4694          * If we are detaching the original disk from a spare, then it implies
4695          * that the spare should become a real disk, and be removed from the
4696          * active spare list for the pool.
4697          */
4698         if (pvd->vdev_ops == &vdev_spare_ops &&
4699             vd->vdev_id == 0 &&
4700             pvd->vdev_child[pvd->vdev_children - 1]->vdev_isspare)
4701                 unspare = B_TRUE;
4702 
4703         /*
4704          * Erase the disk labels so the disk can be used for other things.
4705          * This must be done after all other error cases are handled,
4706          * but before we disembowel vd (so we can still do I/O to it).
4707          * But if we can't do it, don't treat the error as fatal --
4708          * it may be that the unwritability of the disk is the reason
4709          * it's being detached!
4710          */
4711         error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4712 
4713         /*
4714          * Remove vd from its parent and compact the parent's children.
4715          */
4716         vdev_remove_child(pvd, vd);
4717         vdev_compact_children(pvd);
4718 
4719         /*
4720          * Remember one of the remaining children so we can get tvd below.
4721          */
4722         cvd = pvd->vdev_child[pvd->vdev_children - 1];
4723 
4724         /*
4725          * If we need to remove the remaining child from the list of hot spares,
4726          * do it now, marking the vdev as no longer a spare in the process.
4727          * We must do this before vdev_remove_parent(), because that can
4728          * change the GUID if it creates a new toplevel GUID.  For a similar
4729          * reason, we must remove the spare now, in the same txg as the detach;
4730          * otherwise someone could attach a new sibling, change the GUID, and
4731          * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
4732          */
4733         if (unspare) {
4734                 ASSERT(cvd->vdev_isspare);
4735                 spa_spare_remove(cvd);
4736                 unspare_guid = cvd->vdev_guid;
4737                 (void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
4738                 cvd->vdev_unspare = B_TRUE;
4739         }
4740 
4741         /*
4742          * If the parent mirror/replacing vdev only has one child,
4743          * the parent is no longer needed.  Remove it from the tree.
4744          */
4745         if (pvd->vdev_children == 1) {
4746                 if (pvd->vdev_ops == &vdev_spare_ops)
4747                         cvd->vdev_unspare = B_FALSE;
4748                 vdev_remove_parent(cvd);
4749         }
4750 
4751 
4752         /*
4753          * We don't set tvd until now because the parent we just removed
4754          * may have been the previous top-level vdev.
4755          */
4756         tvd = cvd->vdev_top;
4757         ASSERT(tvd->vdev_parent == rvd);
4758 
4759         /*
4760          * Reevaluate the parent vdev state.
4761          */
4762         vdev_propagate_state(cvd);
4763 
4764         /*
4765          * If the 'autoexpand' property is set on the pool then automatically
4766          * try to expand the size of the pool. For example if the device we
4767          * just detached was smaller than the others, it may be possible to
4768          * add metaslabs (i.e. grow the pool). We need to reopen the vdev
4769          * first so that we can obtain the updated sizes of the leaf vdevs.
4770          */
4771         if (spa->spa_autoexpand) {
4772                 vdev_reopen(tvd);
4773                 vdev_expand(tvd, txg);
4774         }
4775 
4776         vdev_config_dirty(tvd);
4777 
4778         /*
4779          * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
4780          * vd->vdev_detached is set and free vd's DTL object in syncing context.
4781          * But first make sure we're not on any *other* txg's DTL list, to
4782          * prevent vd from being accessed after it's freed.
4783          */
4784         vdpath = spa_strdup(vd->vdev_path);
4785         for (int t = 0; t < TXG_SIZE; t++)
4786                 (void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
4787         vd->vdev_detached = B_TRUE;
4788         vdev_dirty(tvd, VDD_DTL, vd, txg);
4789 
4790         spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
4791 
4792         /* hang on to the spa before we release the lock */
4793         spa_open_ref(spa, FTAG);
4794 
4795         error = spa_vdev_exit(spa, vd, txg, 0);
4796 
4797         spa_history_log_internal(spa, "detach", NULL,
4798             "vdev=%s", vdpath);
4799         spa_strfree(vdpath);
4800 
4801         /*
4802          * If this was the removal of the original device in a hot spare vdev,
4803          * then we want to go through and remove the device from the hot spare
4804          * list of every other pool.
4805          */
4806         if (unspare) {
4807                 spa_t *altspa = NULL;
4808 
4809                 mutex_enter(&spa_namespace_lock);
4810                 while ((altspa = spa_next(altspa)) != NULL) {
4811                         if (altspa->spa_state != POOL_STATE_ACTIVE ||
4812                             altspa == spa)
4813                                 continue;
4814 
4815                         spa_open_ref(altspa, FTAG);
4816                         mutex_exit(&spa_namespace_lock);
4817                         (void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
4818                         mutex_enter(&spa_namespace_lock);
4819                         spa_close(altspa, FTAG);
4820                 }
4821                 mutex_exit(&spa_namespace_lock);
4822 
4823                 /* search the rest of the vdevs for spares to remove */
4824                 spa_vdev_resilver_done(spa);
4825         }
4826 
4827         /* all done with the spa; OK to release */
4828         mutex_enter(&spa_namespace_lock);
4829         spa_close(spa, FTAG);
4830         mutex_exit(&spa_namespace_lock);
4831 
4832         return (error);
4833 }
4834 
4835 /*
4836  * Split a set of devices from their mirrors, and create a new pool from them.
4837  */
4838 int
4839 spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
4840     nvlist_t *props, boolean_t exp)
4841 {
4842         int error = 0;
4843         uint64_t txg, *glist;
4844         spa_t *newspa;
4845         uint_t c, children, lastlog;
4846         nvlist_t **child, *nvl, *tmp;
4847         dmu_tx_t *tx;
4848         char *altroot = NULL;
4849         vdev_t *rvd, **vml = NULL;                      /* vdev modify list */
4850         boolean_t activate_slog;
4851 
4852         ASSERT(spa_writeable(spa));
4853 
4854         txg = spa_vdev_enter(spa);
4855 
4856         /* clear the log and flush everything up to now */
4857         activate_slog = spa_passivate_log(spa);
4858         (void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4859         error = spa_offline_log(spa);
4860         txg = spa_vdev_config_enter(spa);
4861 
4862         if (activate_slog)
4863                 spa_activate_log(spa);
4864 
4865         if (error != 0)
4866                 return (spa_vdev_exit(spa, NULL, txg, error));
4867 
4868         /* check new spa name before going any further */
4869         if (spa_lookup(newname) != NULL)
4870                 return (spa_vdev_exit(spa, NULL, txg, EEXIST));
4871 
4872         /*
4873          * scan through all the children to ensure they're all mirrors
4874          */
4875         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
4876             nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
4877             &children) != 0)
4878                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4879 
4880         /* first, check to ensure we've got the right child count */
4881         rvd = spa->spa_root_vdev;
4882         lastlog = 0;
4883         for (c = 0; c < rvd->vdev_children; c++) {
4884                 vdev_t *vd = rvd->vdev_child[c];
4885 
4886                 /* don't count the holes & logs as children */
4887                 if (vd->vdev_islog || vd->vdev_ishole) {
4888                         if (lastlog == 0)
4889                                 lastlog = c;
4890                         continue;
4891                 }
4892 
4893                 lastlog = 0;
4894         }
4895         if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
4896                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4897 
4898         /* next, ensure no spare or cache devices are part of the split */
4899         if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
4900             nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
4901                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4902 
4903         vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
4904         glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
4905 
4906         /* then, loop over each vdev and validate it */
4907         for (c = 0; c < children; c++) {
4908                 uint64_t is_hole = 0;
4909 
4910                 (void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
4911                     &is_hole);
4912 
4913                 if (is_hole != 0) {
4914                         if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
4915                             spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
4916                                 continue;
4917                         } else {
4918                                 error = SET_ERROR(EINVAL);
4919                                 break;
4920                         }
4921                 }
4922 
4923                 /* which disk is going to be split? */
4924                 if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
4925                     &glist[c]) != 0) {
4926                         error = SET_ERROR(EINVAL);
4927                         break;
4928                 }
4929 
4930                 /* look it up in the spa */
4931                 vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
4932                 if (vml[c] == NULL) {
4933                         error = SET_ERROR(ENODEV);
4934                         break;
4935                 }
4936 
4937                 /* make sure there's nothing stopping the split */
4938                 if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
4939                     vml[c]->vdev_islog ||
4940                     vml[c]->vdev_ishole ||
4941                     vml[c]->vdev_isspare ||
4942                     vml[c]->vdev_isl2cache ||
4943                     !vdev_writeable(vml[c]) ||
4944                     vml[c]->vdev_children != 0 ||
4945                     vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
4946                     c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
4947                         error = SET_ERROR(EINVAL);
4948                         break;
4949                 }
4950 
4951                 if (vdev_dtl_required(vml[c])) {
4952                         error = SET_ERROR(EBUSY);
4953                         break;
4954                 }
4955 
4956                 /* we need certain info from the top level */
4957                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
4958                     vml[c]->vdev_top->vdev_ms_array) == 0);
4959                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
4960                     vml[c]->vdev_top->vdev_ms_shift) == 0);
4961                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
4962                     vml[c]->vdev_top->vdev_asize) == 0);
4963                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
4964                     vml[c]->vdev_top->vdev_ashift) == 0);
4965         }
4966 
4967         if (error != 0) {
4968                 kmem_free(vml, children * sizeof (vdev_t *));
4969                 kmem_free(glist, children * sizeof (uint64_t));
4970                 return (spa_vdev_exit(spa, NULL, txg, error));
4971         }
4972 
4973         /* stop writers from using the disks */
4974         for (c = 0; c < children; c++) {
4975                 if (vml[c] != NULL)
4976                         vml[c]->vdev_offline = B_TRUE;
4977         }
4978         vdev_reopen(spa->spa_root_vdev);
4979 
4980         /*
4981          * Temporarily record the splitting vdevs in the spa config.  This
4982          * will disappear once the config is regenerated.
4983          */
4984         VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0);
4985         VERIFY(nvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
4986             glist, children) == 0);
4987         kmem_free(glist, children * sizeof (uint64_t));
4988 
4989         mutex_enter(&spa->spa_props_lock);
4990         VERIFY(nvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT,
4991             nvl) == 0);
4992         mutex_exit(&spa->spa_props_lock);
4993         spa->spa_config_splitting = nvl;
4994         vdev_config_dirty(spa->spa_root_vdev);
4995 
4996         /* configure and create the new pool */
4997         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname) == 0);
4998         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4999             exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE) == 0);
5000         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
5001             spa_version(spa)) == 0);
5002         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
5003             spa->spa_config_txg) == 0);
5004         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
5005             spa_generate_guid(NULL)) == 0);
5006         (void) nvlist_lookup_string(props,
5007             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
5008 
5009         /* add the new pool to the namespace */
5010         newspa = spa_add(newname, config, altroot);
5011         newspa->spa_config_txg = spa->spa_config_txg;
5012         spa_set_log_state(newspa, SPA_LOG_CLEAR);
5013 
5014         /* release the spa config lock, retaining the namespace lock */
5015         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
5016 
5017         if (zio_injection_enabled)
5018                 zio_handle_panic_injection(spa, FTAG, 1);
5019 
5020         spa_activate(newspa, spa_mode_global);
5021         spa_async_suspend(newspa);
5022 
5023         /* create the new pool from the disks of the original pool */
5024         error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE, B_TRUE);
5025         if (error)
5026                 goto out;
5027 
5028         /* if that worked, generate a real config for the new pool */
5029         if (newspa->spa_root_vdev != NULL) {
5030                 VERIFY(nvlist_alloc(&newspa->spa_config_splitting,
5031                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
5032                 VERIFY(nvlist_add_uint64(newspa->spa_config_splitting,
5033                     ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa)) == 0);
5034                 spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
5035                     B_TRUE));
5036         }
5037 
5038         /* set the props */
5039         if (props != NULL) {
5040                 spa_configfile_set(newspa, props, B_FALSE);
5041                 error = spa_prop_set(newspa, props);
5042                 if (error)
5043                         goto out;
5044         }
5045 
5046         /* flush everything */
5047         txg = spa_vdev_config_enter(newspa);
5048         vdev_config_dirty(newspa->spa_root_vdev);
5049         (void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
5050 
5051         if (zio_injection_enabled)
5052                 zio_handle_panic_injection(spa, FTAG, 2);
5053 
5054         spa_async_resume(newspa);
5055 
5056         /* finally, update the original pool's config */
5057         txg = spa_vdev_config_enter(spa);
5058         tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
5059         error = dmu_tx_assign(tx, TXG_WAIT);
5060         if (error != 0)
5061                 dmu_tx_abort(tx);
5062         for (c = 0; c < children; c++) {
5063                 if (vml[c] != NULL) {
5064                         vdev_split(vml[c]);
5065                         if (error == 0)
5066                                 spa_history_log_internal(spa, "detach", tx,
5067                                     "vdev=%s", vml[c]->vdev_path);
5068                         vdev_free(vml[c]);
5069                 }
5070         }
5071         vdev_config_dirty(spa->spa_root_vdev);
5072         spa->spa_config_splitting = NULL;
5073         nvlist_free(nvl);
5074         if (error == 0)
5075                 dmu_tx_commit(tx);
5076         (void) spa_vdev_exit(spa, NULL, txg, 0);
5077 
5078         if (zio_injection_enabled)
5079                 zio_handle_panic_injection(spa, FTAG, 3);
5080 
5081         /* split is complete; log a history record */
5082         spa_history_log_internal(newspa, "split", NULL,
5083             "from pool %s", spa_name(spa));
5084 
5085         kmem_free(vml, children * sizeof (vdev_t *));
5086 
5087         /* if we're not going to mount the filesystems in userland, export */
5088         if (exp)
5089                 error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
5090                     B_FALSE, B_FALSE);
5091 
5092         return (error);
5093 
5094 out:
5095         spa_unload(newspa);
5096         spa_deactivate(newspa);
5097         spa_remove(newspa);
5098 
5099         txg = spa_vdev_config_enter(spa);
5100 
5101         /* re-online all offlined disks */
5102         for (c = 0; c < children; c++) {
5103                 if (vml[c] != NULL)
5104                         vml[c]->vdev_offline = B_FALSE;
5105         }
5106         vdev_reopen(spa->spa_root_vdev);
5107 
5108         nvlist_free(spa->spa_config_splitting);
5109         spa->spa_config_splitting = NULL;
5110         (void) spa_vdev_exit(spa, NULL, txg, error);
5111 
5112         kmem_free(vml, children * sizeof (vdev_t *));
5113         return (error);
5114 }
5115 
5116 static nvlist_t *
5117 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
5118 {
5119         for (int i = 0; i < count; i++) {
5120                 uint64_t guid;
5121 
5122                 VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
5123                     &guid) == 0);
5124 
5125                 if (guid == target_guid)
5126                         return (nvpp[i]);
5127         }
5128 
5129         return (NULL);
5130 }
5131 
5132 static void
5133 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
5134         nvlist_t *dev_to_remove)
5135 {
5136         nvlist_t **newdev = NULL;
5137 
5138         if (count > 1)
5139                 newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
5140 
5141         for (int i = 0, j = 0; i < count; i++) {
5142                 if (dev[i] == dev_to_remove)
5143                         continue;
5144                 VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
5145         }
5146 
5147         VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
5148         VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
5149 
5150         for (int i = 0; i < count - 1; i++)
5151                 nvlist_free(newdev[i]);
5152 
5153         if (count > 1)
5154                 kmem_free(newdev, (count - 1) * sizeof (void *));
5155 }
5156 
5157 /*
5158  * Evacuate the device.
5159  */
5160 static int
5161 spa_vdev_remove_evacuate(spa_t *spa, vdev_t *vd)
5162 {
5163         uint64_t txg;
5164         int error = 0;
5165 
5166         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5167         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5168         ASSERT(vd == vd->vdev_top);
5169 
5170         /*
5171          * Evacuate the device.  We don't hold the config lock as writer
5172          * since we need to do I/O but we do keep the
5173          * spa_namespace_lock held.  Once this completes the device
5174          * should no longer have any blocks allocated on it.
5175          */
5176         if (vd->vdev_islog) {
5177                 if (vd->vdev_stat.vs_alloc != 0)
5178                         error = spa_offline_log(spa);
5179         } else {
5180                 error = SET_ERROR(ENOTSUP);
5181         }
5182 
5183         if (error)
5184                 return (error);
5185 
5186         /*
5187          * The evacuation succeeded.  Remove any remaining MOS metadata
5188          * associated with this vdev, and wait for these changes to sync.
5189          */
5190         ASSERT0(vd->vdev_stat.vs_alloc);
5191         txg = spa_vdev_config_enter(spa);
5192         vd->vdev_removing = B_TRUE;
5193         vdev_dirty_leaves(vd, VDD_DTL, txg);
5194         vdev_config_dirty(vd);
5195         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
5196 
5197         return (0);
5198 }
5199 
5200 /*
5201  * Complete the removal by cleaning up the namespace.
5202  */
5203 static void
5204 spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
5205 {
5206         vdev_t *rvd = spa->spa_root_vdev;
5207         uint64_t id = vd->vdev_id;
5208         boolean_t last_vdev = (id == (rvd->vdev_children - 1));
5209 
5210         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5211         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
5212         ASSERT(vd == vd->vdev_top);
5213 
5214         /*
5215          * Only remove any devices which are empty.
5216          */
5217         if (vd->vdev_stat.vs_alloc != 0)
5218                 return;
5219 
5220         (void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
5221 
5222         if (list_link_active(&vd->vdev_state_dirty_node))
5223                 vdev_state_clean(vd);
5224         if (list_link_active(&vd->vdev_config_dirty_node))
5225                 vdev_config_clean(vd);
5226 
5227         vdev_free(vd);
5228 
5229         if (last_vdev) {
5230                 vdev_compact_children(rvd);
5231         } else {
5232                 vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops);
5233                 vdev_add_child(rvd, vd);
5234         }
5235         vdev_config_dirty(rvd);
5236 
5237         /*
5238          * Reassess the health of our root vdev.
5239          */
5240         vdev_reopen(rvd);
5241 }
5242 
5243 /*
5244  * Remove a device from the pool -
5245  *
5246  * Removing a device from the vdev namespace requires several steps
5247  * and can take a significant amount of time.  As a result we use
5248  * the spa_vdev_config_[enter/exit] functions which allow us to
5249  * grab and release the spa_config_lock while still holding the namespace
5250  * lock.  During each step the configuration is synced out.
5251  *
5252  * Currently, this supports removing only hot spares, slogs, and level 2 ARC
5253  * devices.
5254  */
5255 int
5256 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
5257 {
5258         vdev_t *vd;
5259         metaslab_group_t *mg;
5260         nvlist_t **spares, **l2cache, *nv;
5261         uint64_t txg = 0;
5262         uint_t nspares, nl2cache;
5263         int error = 0;
5264         boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
5265 
5266         ASSERT(spa_writeable(spa));
5267 
5268         if (!locked)
5269                 txg = spa_vdev_enter(spa);
5270 
5271         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
5272 
5273         if (spa->spa_spares.sav_vdevs != NULL &&
5274             nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
5275             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
5276             (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
5277                 /*
5278                  * Only remove the hot spare if it's not currently in use
5279                  * in this pool.
5280                  */
5281                 if (vd == NULL || unspare) {
5282                         spa_vdev_remove_aux(spa->spa_spares.sav_config,
5283                             ZPOOL_CONFIG_SPARES, spares, nspares, nv);
5284                         spa_load_spares(spa);
5285                         spa->spa_spares.sav_sync = B_TRUE;
5286                 } else {
5287                         error = SET_ERROR(EBUSY);
5288                 }
5289         } else if (spa->spa_l2cache.sav_vdevs != NULL &&
5290             nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
5291             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
5292             (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
5293                 /*
5294                  * Cache devices can always be removed.
5295                  */
5296                 spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
5297                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
5298                 spa_load_l2cache(spa);
5299                 spa->spa_l2cache.sav_sync = B_TRUE;
5300         } else if (vd != NULL && vd->vdev_islog) {
5301                 ASSERT(!locked);
5302                 ASSERT(vd == vd->vdev_top);
5303 
5304                 mg = vd->vdev_mg;
5305 
5306                 /*
5307                  * Stop allocating from this vdev.
5308                  */
5309                 metaslab_group_passivate(mg);
5310 
5311                 /*
5312                  * Wait for the youngest allocations and frees to sync,
5313                  * and then wait for the deferral of those frees to finish.
5314                  */
5315                 spa_vdev_config_exit(spa, NULL,
5316                     txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
5317 
5318                 /*
5319                  * Attempt to evacuate the vdev.
5320                  */
5321                 error = spa_vdev_remove_evacuate(spa, vd);
5322 
5323                 txg = spa_vdev_config_enter(spa);
5324 
5325                 /*
5326                  * If we couldn't evacuate the vdev, unwind.
5327                  */
5328                 if (error) {
5329                         metaslab_group_activate(mg);
5330                         return (spa_vdev_exit(spa, NULL, txg, error));
5331                 }
5332 
5333                 /*
5334                  * Clean up the vdev namespace.
5335                  */
5336                 spa_vdev_remove_from_namespace(spa, vd);
5337 
5338         } else if (vd != NULL) {
5339                 /*
5340                  * Normal vdevs cannot be removed (yet).
5341                  */
5342                 error = SET_ERROR(ENOTSUP);
5343         } else {
5344                 /*
5345                  * There is no vdev of any kind with the specified guid.
5346                  */
5347                 error = SET_ERROR(ENOENT);
5348         }
5349 
5350         if (!locked)
5351                 return (spa_vdev_exit(spa, NULL, txg, error));
5352 
5353         return (error);
5354 }
5355 
5356 /*
5357  * Find any device that's done replacing, or a vdev marked 'unspare' that's
5358  * currently spared, so we can detach it.
5359  */
5360 static vdev_t *
5361 spa_vdev_resilver_done_hunt(vdev_t *vd)
5362 {
5363         vdev_t *newvd, *oldvd;
5364 
5365         for (int c = 0; c < vd->vdev_children; c++) {
5366                 oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
5367                 if (oldvd != NULL)
5368                         return (oldvd);
5369         }
5370 
5371         /*
5372          * Check for a completed replacement.  We always consider the first
5373          * vdev in the list to be the oldest vdev, and the last one to be
5374          * the newest (see spa_vdev_attach() for how that works).  In
5375          * the case where the newest vdev is faulted, we will not automatically
5376          * remove it after a resilver completes.  This is OK as it will require
5377          * user intervention to determine which disk the admin wishes to keep.
5378          */
5379         if (vd->vdev_ops == &vdev_replacing_ops) {
5380                 ASSERT(vd->vdev_children > 1);
5381 
5382                 newvd = vd->vdev_child[vd->vdev_children - 1];
5383                 oldvd = vd->vdev_child[0];
5384 
5385                 if (vdev_dtl_empty(newvd, DTL_MISSING) &&
5386                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5387                     !vdev_dtl_required(oldvd))
5388                         return (oldvd);
5389         }
5390 
5391         /*
5392          * Check for a completed resilver with the 'unspare' flag set.
5393          */
5394         if (vd->vdev_ops == &vdev_spare_ops) {
5395                 vdev_t *first = vd->vdev_child[0];
5396                 vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
5397 
5398                 if (last->vdev_unspare) {
5399                         oldvd = first;
5400                         newvd = last;
5401                 } else if (first->vdev_unspare) {
5402                         oldvd = last;
5403                         newvd = first;
5404                 } else {
5405                         oldvd = NULL;
5406                 }
5407 
5408                 if (oldvd != NULL &&
5409                     vdev_dtl_empty(newvd, DTL_MISSING) &&
5410                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5411                     !vdev_dtl_required(oldvd))
5412                         return (oldvd);
5413 
5414                 /*
5415                  * If there are more than two spares attached to a disk,
5416                  * and those spares are not required, then we want to
5417                  * attempt to free them up now so that they can be used
5418                  * by other pools.  Once we're back down to a single
5419                  * disk+spare, we stop removing them.
5420                  */
5421                 if (vd->vdev_children > 2) {
5422                         newvd = vd->vdev_child[1];
5423 
5424                         if (newvd->vdev_isspare && last->vdev_isspare &&
5425                             vdev_dtl_empty(last, DTL_MISSING) &&
5426                             vdev_dtl_empty(last, DTL_OUTAGE) &&
5427                             !vdev_dtl_required(newvd))
5428                                 return (newvd);
5429                 }
5430         }
5431 
5432         return (NULL);
5433 }
5434 
5435 static void
5436 spa_vdev_resilver_done(spa_t *spa)
5437 {
5438         vdev_t *vd, *pvd, *ppvd;
5439         uint64_t guid, sguid, pguid, ppguid;
5440 
5441         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5442 
5443         while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
5444                 pvd = vd->vdev_parent;
5445                 ppvd = pvd->vdev_parent;
5446                 guid = vd->vdev_guid;
5447                 pguid = pvd->vdev_guid;
5448                 ppguid = ppvd->vdev_guid;
5449                 sguid = 0;
5450                 /*
5451                  * If we have just finished replacing a hot spared device, then
5452                  * we need to detach the parent's first child (the original hot
5453                  * spare) as well.
5454                  */
5455                 if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
5456                     ppvd->vdev_children == 2) {
5457                         ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
5458                         sguid = ppvd->vdev_child[1]->vdev_guid;
5459                 }
5460                 ASSERT(vd->vdev_resilver_txg == 0 || !vdev_dtl_required(vd));
5461 
5462                 spa_config_exit(spa, SCL_ALL, FTAG);
5463                 if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
5464                         return;
5465                 if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
5466                         return;
5467                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5468         }
5469 
5470         spa_config_exit(spa, SCL_ALL, FTAG);
5471 }
5472 
5473 /*
5474  * Update the stored path or FRU for this vdev.
5475  */
5476 int
5477 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
5478     boolean_t ispath)
5479 {
5480         vdev_t *vd;
5481         boolean_t sync = B_FALSE;
5482 
5483         ASSERT(spa_writeable(spa));
5484 
5485         spa_vdev_state_enter(spa, SCL_ALL);
5486 
5487         if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
5488                 return (spa_vdev_state_exit(spa, NULL, ENOENT));
5489 
5490         if (!vd->vdev_ops->vdev_op_leaf)
5491                 return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
5492 
5493         if (ispath) {
5494                 if (strcmp(value, vd->vdev_path) != 0) {
5495                         spa_strfree(vd->vdev_path);
5496                         vd->vdev_path = spa_strdup(value);
5497                         sync = B_TRUE;
5498                 }
5499         } else {
5500                 if (vd->vdev_fru == NULL) {
5501                         vd->vdev_fru = spa_strdup(value);
5502                         sync = B_TRUE;
5503                 } else if (strcmp(value, vd->vdev_fru) != 0) {
5504                         spa_strfree(vd->vdev_fru);
5505                         vd->vdev_fru = spa_strdup(value);
5506                         sync = B_TRUE;
5507                 }
5508         }
5509 
5510         return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
5511 }
5512 
5513 int
5514 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
5515 {
5516         return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
5517 }
5518 
5519 int
5520 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
5521 {
5522         return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
5523 }
5524 
5525 /*
5526  * ==========================================================================
5527  * SPA Scanning
5528  * ==========================================================================
5529  */
5530 
5531 int
5532 spa_scan_stop(spa_t *spa)
5533 {
5534         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5535         if (dsl_scan_resilvering(spa->spa_dsl_pool))
5536                 return (SET_ERROR(EBUSY));
5537         return (dsl_scan_cancel(spa->spa_dsl_pool));
5538 }
5539 
5540 int
5541 spa_scan(spa_t *spa, pool_scan_func_t func)
5542 {
5543         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5544 
5545         if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
5546                 return (SET_ERROR(ENOTSUP));
5547 
5548         /*
5549          * If a resilver was requested, but there is no DTL on a
5550          * writeable leaf device, we have nothing to do.
5551          */
5552         if (func == POOL_SCAN_RESILVER &&
5553             !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
5554                 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
5555                 return (0);
5556         }
5557 
5558         return (dsl_scan(spa->spa_dsl_pool, func));
5559 }
5560 
5561 /*
5562  * ==========================================================================
5563  * SPA async task processing
5564  * ==========================================================================
5565  */
5566 
5567 static void
5568 spa_async_remove(spa_t *spa, vdev_t *vd)
5569 {
5570         if (vd->vdev_remove_wanted) {
5571                 vd->vdev_remove_wanted = B_FALSE;
5572                 vd->vdev_delayed_close = B_FALSE;
5573                 vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
5574 
5575                 /*
5576                  * We want to clear the stats, but we don't want to do a full
5577                  * vdev_clear() as that will cause us to throw away
5578                  * degraded/faulted state as well as attempt to reopen the
5579                  * device, all of which is a waste.
5580                  */
5581                 vd->vdev_stat.vs_read_errors = 0;
5582                 vd->vdev_stat.vs_write_errors = 0;
5583                 vd->vdev_stat.vs_checksum_errors = 0;
5584 
5585                 vdev_state_dirty(vd->vdev_top);
5586         }
5587 
5588         for (int c = 0; c < vd->vdev_children; c++)
5589                 spa_async_remove(spa, vd->vdev_child[c]);
5590 }
5591 
5592 static void
5593 spa_async_probe(spa_t *spa, vdev_t *vd)
5594 {
5595         if (vd->vdev_probe_wanted) {
5596                 vd->vdev_probe_wanted = B_FALSE;
5597                 vdev_reopen(vd);        /* vdev_open() does the actual probe */
5598         }
5599 
5600         for (int c = 0; c < vd->vdev_children; c++)
5601                 spa_async_probe(spa, vd->vdev_child[c]);
5602 }
5603 
5604 static void
5605 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
5606 {
5607         sysevent_id_t eid;
5608         nvlist_t *attr;
5609         char *physpath;
5610 
5611         if (!spa->spa_autoexpand)
5612                 return;
5613 
5614         for (int c = 0; c < vd->vdev_children; c++) {
5615                 vdev_t *cvd = vd->vdev_child[c];
5616                 spa_async_autoexpand(spa, cvd);
5617         }
5618 
5619         if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
5620                 return;
5621 
5622         physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
5623         (void) snprintf(physpath, MAXPATHLEN, "/devices%s", vd->vdev_physpath);
5624 
5625         VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5626         VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
5627 
5628         (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
5629             ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
5630 
5631         nvlist_free(attr);
5632         kmem_free(physpath, MAXPATHLEN);
5633 }
5634 
5635 static void
5636 spa_async_thread(spa_t *spa)
5637 {
5638         int tasks;
5639 
5640         ASSERT(spa->spa_sync_on);
5641 
5642         mutex_enter(&spa->spa_async_lock);
5643         tasks = spa->spa_async_tasks;
5644         spa->spa_async_tasks = 0;
5645         mutex_exit(&spa->spa_async_lock);
5646 
5647         /*
5648          * See if the config needs to be updated.
5649          */
5650         if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
5651                 uint64_t old_space, new_space;
5652 
5653                 mutex_enter(&spa_namespace_lock);
5654                 old_space = metaslab_class_get_space(spa_normal_class(spa));
5655                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
5656                 new_space = metaslab_class_get_space(spa_normal_class(spa));
5657                 mutex_exit(&spa_namespace_lock);
5658 
5659                 /*
5660                  * If the pool grew as a result of the config update,
5661                  * then log an internal history event.
5662                  */
5663                 if (new_space != old_space) {
5664                         spa_history_log_internal(spa, "vdev online", NULL,
5665                             "pool '%s' size: %llu(+%llu)",
5666                             spa_name(spa), new_space, new_space - old_space);
5667                 }
5668         }
5669 
5670         /*
5671          * See if any devices need to be marked REMOVED.
5672          */
5673         if (tasks & SPA_ASYNC_REMOVE) {
5674                 spa_vdev_state_enter(spa, SCL_NONE);
5675                 spa_async_remove(spa, spa->spa_root_vdev);
5676                 for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
5677                         spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
5678                 for (int i = 0; i < spa->spa_spares.sav_count; i++)
5679                         spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
5680                 (void) spa_vdev_state_exit(spa, NULL, 0);
5681         }
5682 
5683         if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
5684                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5685                 spa_async_autoexpand(spa, spa->spa_root_vdev);
5686                 spa_config_exit(spa, SCL_CONFIG, FTAG);
5687         }
5688 
5689         /*
5690          * See if any devices need to be probed.
5691          */
5692         if (tasks & SPA_ASYNC_PROBE) {
5693                 spa_vdev_state_enter(spa, SCL_NONE);
5694                 spa_async_probe(spa, spa->spa_root_vdev);
5695                 (void) spa_vdev_state_exit(spa, NULL, 0);
5696         }
5697 
5698         /*
5699          * If any devices are done replacing, detach them.
5700          */
5701         if (tasks & SPA_ASYNC_RESILVER_DONE)
5702                 spa_vdev_resilver_done(spa);
5703 
5704         /*
5705          * Kick off a resilver.
5706          */
5707         if (tasks & SPA_ASYNC_RESILVER)
5708                 dsl_resilver_restart(spa->spa_dsl_pool, 0);
5709 
5710         /*
5711          * Let the world know that we're done.
5712          */
5713         mutex_enter(&spa->spa_async_lock);
5714         spa->spa_async_thread = NULL;
5715         cv_broadcast(&spa->spa_async_cv);
5716         mutex_exit(&spa->spa_async_lock);
5717         thread_exit();
5718 }
5719 
5720 void
5721 spa_async_suspend(spa_t *spa)
5722 {
5723         mutex_enter(&spa->spa_async_lock);
5724         spa->spa_async_suspended++;
5725         while (spa->spa_async_thread != NULL)
5726                 cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
5727         mutex_exit(&spa->spa_async_lock);
5728 }
5729 
5730 void
5731 spa_async_resume(spa_t *spa)
5732 {
5733         mutex_enter(&spa->spa_async_lock);
5734         ASSERT(spa->spa_async_suspended != 0);
5735         spa->spa_async_suspended--;
5736         mutex_exit(&spa->spa_async_lock);
5737 }
5738 
5739 static boolean_t
5740 spa_async_tasks_pending(spa_t *spa)
5741 {
5742         uint_t non_config_tasks;
5743         uint_t config_task;
5744         boolean_t config_task_suspended;
5745 
5746         non_config_tasks = spa->spa_async_tasks & ~SPA_ASYNC_CONFIG_UPDATE;
5747         config_task = spa->spa_async_tasks & SPA_ASYNC_CONFIG_UPDATE;
5748         if (spa->spa_ccw_fail_time == 0) {
5749                 config_task_suspended = B_FALSE;
5750         } else {
5751                 config_task_suspended =
5752                     (gethrtime() - spa->spa_ccw_fail_time) <
5753                     (zfs_ccw_retry_interval * NANOSEC);
5754         }
5755 
5756         return (non_config_tasks || (config_task && !config_task_suspended));
5757 }
5758 
5759 static void
5760 spa_async_dispatch(spa_t *spa)
5761 {
5762         mutex_enter(&spa->spa_async_lock);
5763         if (spa_async_tasks_pending(spa) &&
5764             !spa->spa_async_suspended &&
5765             spa->spa_async_thread == NULL &&
5766             rootdir != NULL)
5767                 spa->spa_async_thread = thread_create(NULL, 0,
5768                     spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
5769         mutex_exit(&spa->spa_async_lock);
5770 }
5771 
5772 void
5773 spa_async_request(spa_t *spa, int task)
5774 {
5775         zfs_dbgmsg("spa=%s async request task=%u", spa->spa_name, task);
5776         mutex_enter(&spa->spa_async_lock);
5777         spa->spa_async_tasks |= task;
5778         mutex_exit(&spa->spa_async_lock);
5779 }
5780 
5781 /*
5782  * ==========================================================================
5783  * SPA syncing routines
5784  * ==========================================================================
5785  */
5786 
5787 static int
5788 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5789 {
5790         bpobj_t *bpo = arg;
5791         bpobj_enqueue(bpo, bp, tx);
5792         return (0);
5793 }
5794 
5795 static int
5796 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5797 {
5798         zio_t *zio = arg;
5799 
5800         zio_nowait(zio_free_sync(zio, zio->io_spa, dmu_tx_get_txg(tx), bp,
5801             zio->io_flags));
5802         return (0);
5803 }
5804 
5805 /*
5806  * Note: this simple function is not inlined to make it easier to dtrace the
5807  * amount of time spent syncing frees.
5808  */
5809 static void
5810 spa_sync_frees(spa_t *spa, bplist_t *bpl, dmu_tx_t *tx)
5811 {
5812         zio_t *zio = zio_root(spa, NULL, NULL, 0);
5813         bplist_iterate(bpl, spa_free_sync_cb, zio, tx);
5814         VERIFY(zio_wait(zio) == 0);
5815 }
5816 
5817 /*
5818  * Note: this simple function is not inlined to make it easier to dtrace the
5819  * amount of time spent syncing deferred frees.
5820  */
5821 static void
5822 spa_sync_deferred_frees(spa_t *spa, dmu_tx_t *tx)
5823 {
5824         zio_t *zio = zio_root(spa, NULL, NULL, 0);
5825         VERIFY3U(bpobj_iterate(&spa->spa_deferred_bpobj,
5826             spa_free_sync_cb, zio, tx), ==, 0);
5827         VERIFY0(zio_wait(zio));
5828 }
5829 
5830 
5831 static void
5832 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
5833 {
5834         char *packed = NULL;
5835         size_t bufsize;
5836         size_t nvsize = 0;
5837         dmu_buf_t *db;
5838 
5839         VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
5840 
5841         /*
5842          * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
5843          * information.  This avoids the dmu_buf_will_dirty() path and
5844          * saves us a pre-read to get data we don't actually care about.
5845          */
5846         bufsize = P2ROUNDUP((uint64_t)nvsize, SPA_CONFIG_BLOCKSIZE);
5847         packed = kmem_alloc(bufsize, KM_SLEEP);
5848 
5849         VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
5850             KM_SLEEP) == 0);
5851         bzero(packed + nvsize, bufsize - nvsize);
5852 
5853         dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
5854 
5855         kmem_free(packed, bufsize);
5856 
5857         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
5858         dmu_buf_will_dirty(db, tx);
5859         *(uint64_t *)db->db_data = nvsize;
5860         dmu_buf_rele(db, FTAG);
5861 }
5862 
5863 static void
5864 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
5865     const char *config, const char *entry)
5866 {
5867         nvlist_t *nvroot;
5868         nvlist_t **list;
5869         int i;
5870 
5871         if (!sav->sav_sync)
5872                 return;
5873 
5874         /*
5875          * Update the MOS nvlist describing the list of available devices.
5876          * spa_validate_aux() will have already made sure this nvlist is
5877          * valid and the vdevs are labeled appropriately.
5878          */
5879         if (sav->sav_object == 0) {
5880                 sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
5881                     DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
5882                     sizeof (uint64_t), tx);
5883                 VERIFY(zap_update(spa->spa_meta_objset,
5884                     DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
5885                     &sav->sav_object, tx) == 0);
5886         }
5887 
5888         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5889         if (sav->sav_count == 0) {
5890                 VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
5891         } else {
5892                 list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
5893                 for (i = 0; i < sav->sav_count; i++)
5894                         list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
5895                             B_FALSE, VDEV_CONFIG_L2CACHE);
5896                 VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
5897                     sav->sav_count) == 0);
5898                 for (i = 0; i < sav->sav_count; i++)
5899                         nvlist_free(list[i]);
5900                 kmem_free(list, sav->sav_count * sizeof (void *));
5901         }
5902 
5903         spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
5904         nvlist_free(nvroot);
5905 
5906         sav->sav_sync = B_FALSE;
5907 }
5908 
5909 static void
5910 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
5911 {
5912         nvlist_t *config;
5913 
5914         if (list_is_empty(&spa->spa_config_dirty_list))
5915                 return;
5916 
5917         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5918 
5919         config = spa_config_generate(spa, spa->spa_root_vdev,
5920             dmu_tx_get_txg(tx), B_FALSE);
5921 
5922         /*
5923          * If we're upgrading the spa version then make sure that
5924          * the config object gets updated with the correct version.
5925          */
5926         if (spa->spa_ubsync.ub_version < spa->spa_uberblock.ub_version)
5927                 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
5928                     spa->spa_uberblock.ub_version);
5929 
5930         spa_config_exit(spa, SCL_STATE, FTAG);
5931 
5932         if (spa->spa_config_syncing)
5933                 nvlist_free(spa->spa_config_syncing);
5934         spa->spa_config_syncing = config;
5935 
5936         spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
5937 }
5938 
5939 static void
5940 spa_sync_version(void *arg, dmu_tx_t *tx)
5941 {
5942         uint64_t *versionp = arg;
5943         uint64_t version = *versionp;
5944         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5945 
5946         /*
5947          * Setting the version is special cased when first creating the pool.
5948          */
5949         ASSERT(tx->tx_txg != TXG_INITIAL);
5950 
5951         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
5952         ASSERT(version >= spa_version(spa));
5953 
5954         spa->spa_uberblock.ub_version = version;
5955         vdev_config_dirty(spa->spa_root_vdev);
5956         spa_history_log_internal(spa, "set", tx, "version=%lld", version);
5957 }
5958 
5959 /*
5960  * Set zpool properties.
5961  */
5962 static void
5963 spa_sync_props(void *arg, dmu_tx_t *tx)
5964 {
5965         nvlist_t *nvp = arg;
5966         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5967         objset_t *mos = spa->spa_meta_objset;
5968         nvpair_t *elem = NULL;
5969 
5970         mutex_enter(&spa->spa_props_lock);
5971 
5972         while ((elem = nvlist_next_nvpair(nvp, elem))) {
5973                 uint64_t intval;
5974                 char *strval, *fname;
5975                 zpool_prop_t prop;
5976                 const char *propname;
5977                 zprop_type_t proptype;
5978                 spa_feature_t fid;
5979 
5980                 switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
5981                 case ZPROP_INVAL:
5982                         /*
5983                          * We checked this earlier in spa_prop_validate().
5984                          */
5985                         ASSERT(zpool_prop_feature(nvpair_name(elem)));
5986 
5987                         fname = strchr(nvpair_name(elem), '@') + 1;
5988                         VERIFY0(zfeature_lookup_name(fname, &fid));
5989 
5990                         spa_feature_enable(spa, fid, tx);
5991                         spa_history_log_internal(spa, "set", tx,
5992                             "%s=enabled", nvpair_name(elem));
5993                         break;
5994 
5995                 case ZPOOL_PROP_VERSION:
5996                         intval = fnvpair_value_uint64(elem);
5997                         /*
5998                          * The version is synced seperatly before other
5999                          * properties and should be correct by now.
6000                          */
6001                         ASSERT3U(spa_version(spa), >=, intval);
6002                         break;
6003 
6004                 case ZPOOL_PROP_ALTROOT:
6005                         /*
6006                          * 'altroot' is a non-persistent property. It should
6007                          * have been set temporarily at creation or import time.
6008                          */
6009                         ASSERT(spa->spa_root != NULL);
6010                         break;
6011 
6012                 case ZPOOL_PROP_READONLY:
6013                 case ZPOOL_PROP_CACHEFILE:
6014                         /*
6015                          * 'readonly' and 'cachefile' are also non-persisitent
6016                          * properties.
6017                          */
6018                         break;
6019                 case ZPOOL_PROP_COMMENT:
6020                         strval = fnvpair_value_string(elem);
6021                         if (spa->spa_comment != NULL)
6022                                 spa_strfree(spa->spa_comment);
6023                         spa->spa_comment = spa_strdup(strval);
6024                         /*
6025                          * We need to dirty the configuration on all the vdevs
6026                          * so that their labels get updated.  It's unnecessary
6027                          * to do this for pool creation since the vdev's
6028                          * configuratoin has already been dirtied.
6029                          */
6030                         if (tx->tx_txg != TXG_INITIAL)
6031                                 vdev_config_dirty(spa->spa_root_vdev);
6032                         spa_history_log_internal(spa, "set", tx,
6033                             "%s=%s", nvpair_name(elem), strval);
6034                         break;
6035                 default:
6036                         /*
6037                          * Set pool property values in the poolprops mos object.
6038                          */
6039                         if (spa->spa_pool_props_object == 0) {
6040                                 spa->spa_pool_props_object =
6041                                     zap_create_link(mos, DMU_OT_POOL_PROPS,
6042                                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
6043                                     tx);
6044                         }
6045 
6046                         /* normalize the property name */
6047                         propname = zpool_prop_to_name(prop);
6048                         proptype = zpool_prop_get_type(prop);
6049 
6050                         if (nvpair_type(elem) == DATA_TYPE_STRING) {
6051                                 ASSERT(proptype == PROP_TYPE_STRING);
6052                                 strval = fnvpair_value_string(elem);
6053                                 VERIFY0(zap_update(mos,
6054                                     spa->spa_pool_props_object, propname,
6055                                     1, strlen(strval) + 1, strval, tx));
6056                                 spa_history_log_internal(spa, "set", tx,
6057                                     "%s=%s", nvpair_name(elem), strval);
6058                         } else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
6059                                 intval = fnvpair_value_uint64(elem);
6060 
6061                                 if (proptype == PROP_TYPE_INDEX) {
6062                                         const char *unused;
6063                                         VERIFY0(zpool_prop_index_to_string(
6064                                             prop, intval, &unused));
6065                                 }
6066                                 VERIFY0(zap_update(mos,
6067                                     spa->spa_pool_props_object, propname,
6068                                     8, 1, &intval, tx));
6069                                 spa_history_log_internal(spa, "set", tx,
6070                                     "%s=%lld", nvpair_name(elem), intval);
6071                         } else {
6072                                 ASSERT(0); /* not allowed */
6073                         }
6074 
6075                         switch (prop) {
6076                         case ZPOOL_PROP_DELEGATION:
6077                                 spa->spa_delegation = intval;
6078                                 break;
6079                         case ZPOOL_PROP_BOOTFS:
6080                                 spa->spa_bootfs = intval;
6081                                 break;
6082                         case ZPOOL_PROP_FAILUREMODE:
6083                                 spa->spa_failmode = intval;
6084                                 break;
6085                         case ZPOOL_PROP_AUTOEXPAND:
6086                                 spa->spa_autoexpand = intval;
6087                                 if (tx->tx_txg != TXG_INITIAL)
6088                                         spa_async_request(spa,
6089                                             SPA_ASYNC_AUTOEXPAND);
6090                                 break;
6091                         case ZPOOL_PROP_DEDUPDITTO:
6092                                 spa->spa_dedup_ditto = intval;
6093                                 break;
6094                         default:
6095                                 break;
6096                         }
6097                 }
6098 
6099         }
6100 
6101         mutex_exit(&spa->spa_props_lock);
6102 }
6103 
6104 /*
6105  * Perform one-time upgrade on-disk changes.  spa_version() does not
6106  * reflect the new version this txg, so there must be no changes this
6107  * txg to anything that the upgrade code depends on after it executes.
6108  * Therefore this must be called after dsl_pool_sync() does the sync
6109  * tasks.
6110  */
6111 static void
6112 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
6113 {
6114         dsl_pool_t *dp = spa->spa_dsl_pool;
6115 
6116         ASSERT(spa->spa_sync_pass == 1);
6117 
6118         rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
6119 
6120         if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
6121             spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
6122                 dsl_pool_create_origin(dp, tx);
6123 
6124                 /* Keeping the origin open increases spa_minref */
6125                 spa->spa_minref += 3;
6126         }
6127 
6128         if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
6129             spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
6130                 dsl_pool_upgrade_clones(dp, tx);
6131         }
6132 
6133         if (spa->spa_ubsync.ub_version < SPA_VERSION_DIR_CLONES &&
6134             spa->spa_uberblock.ub_version >= SPA_VERSION_DIR_CLONES) {
6135                 dsl_pool_upgrade_dir_clones(dp, tx);
6136 
6137                 /* Keeping the freedir open increases spa_minref */
6138                 spa->spa_minref += 3;
6139         }
6140 
6141         if (spa->spa_ubsync.ub_version < SPA_VERSION_FEATURES &&
6142             spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
6143                 spa_feature_create_zap_objects(spa, tx);
6144         }
6145 
6146         /*
6147          * LZ4_COMPRESS feature's behaviour was changed to activate_on_enable
6148          * when possibility to use lz4 compression for metadata was added
6149          * Old pools that have this feature enabled must be upgraded to have
6150          * this feature active
6151          */
6152         if (spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
6153                 boolean_t lz4_en = spa_feature_is_enabled(spa,
6154                     SPA_FEATURE_LZ4_COMPRESS);
6155                 boolean_t lz4_ac = spa_feature_is_active(spa,
6156                     SPA_FEATURE_LZ4_COMPRESS);
6157 
6158                 if (lz4_en && !lz4_ac)
6159                         spa_feature_incr(spa, SPA_FEATURE_LZ4_COMPRESS, tx);
6160         }
6161         rrw_exit(&dp->dp_config_rwlock, FTAG);
6162 }
6163 
6164 /*
6165  * Sync the specified transaction group.  New blocks may be dirtied as
6166  * part of the process, so we iterate until it converges.
6167  */
6168 void
6169 spa_sync(spa_t *spa, uint64_t txg)
6170 {
6171         dsl_pool_t *dp = spa->spa_dsl_pool;
6172         objset_t *mos = spa->spa_meta_objset;
6173         bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
6174         vdev_t *rvd = spa->spa_root_vdev;
6175         vdev_t *vd;
6176         dmu_tx_t *tx;
6177         int error;
6178 
6179         VERIFY(spa_writeable(spa));
6180 
6181         /*
6182          * Lock out configuration changes.
6183          */
6184         spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
6185 
6186         spa->spa_syncing_txg = txg;
6187         spa->spa_sync_pass = 0;
6188 
6189         /*
6190          * If there are any pending vdev state changes, convert them
6191          * into config changes that go out with this transaction group.
6192          */
6193         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6194         while (list_head(&spa->spa_state_dirty_list) != NULL) {
6195                 /*
6196                  * We need the write lock here because, for aux vdevs,
6197                  * calling vdev_config_dirty() modifies sav_config.
6198                  * This is ugly and will become unnecessary when we
6199                  * eliminate the aux vdev wart by integrating all vdevs
6200                  * into the root vdev tree.
6201                  */
6202                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6203                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
6204                 while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
6205                         vdev_state_clean(vd);
6206                         vdev_config_dirty(vd);
6207                 }
6208                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6209                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
6210         }
6211         spa_config_exit(spa, SCL_STATE, FTAG);
6212 
6213         tx = dmu_tx_create_assigned(dp, txg);
6214 
6215         spa->spa_sync_starttime = gethrtime();
6216         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid,
6217             spa->spa_sync_starttime + spa->spa_deadman_synctime));
6218 
6219         /*
6220          * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
6221          * set spa_deflate if we have no raid-z vdevs.
6222          */
6223         if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
6224             spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
6225                 int i;
6226 
6227                 for (i = 0; i < rvd->vdev_children; i++) {
6228                         vd = rvd->vdev_child[i];
6229                         if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
6230                                 break;
6231                 }
6232                 if (i == rvd->vdev_children) {
6233                         spa->spa_deflate = TRUE;
6234                         VERIFY(0 == zap_add(spa->spa_meta_objset,
6235                             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
6236                             sizeof (uint64_t), 1, &spa->spa_deflate, tx));
6237                 }
6238         }
6239 
6240         /*
6241          * If anything has changed in this txg, or if someone is waiting
6242          * for this txg to sync (eg, spa_vdev_remove()), push the
6243          * deferred frees from the previous txg.  If not, leave them
6244          * alone so that we don't generate work on an otherwise idle
6245          * system.
6246          */
6247         if (!txg_list_empty(&dp->dp_dirty_datasets, txg) ||
6248             !txg_list_empty(&dp->dp_dirty_dirs, txg) ||
6249             !txg_list_empty(&dp->dp_sync_tasks, txg) ||
6250             ((dsl_scan_active(dp->dp_scan) ||
6251             txg_sync_waiting(dp)) && !spa_shutting_down(spa))) {
6252                 spa_sync_deferred_frees(spa, tx);
6253         }
6254 
6255         /*
6256          * Iterate to convergence.
6257          */
6258         do {
6259                 int pass = ++spa->spa_sync_pass;
6260 
6261                 spa_sync_config_object(spa, tx);
6262                 spa_sync_aux_dev(spa, &spa->spa_spares, tx,
6263                     ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
6264                 spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
6265                     ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
6266                 spa_errlog_sync(spa, txg);
6267                 dsl_pool_sync(dp, txg);
6268 
6269                 if (pass < zfs_sync_pass_deferred_free) {
6270                         spa_sync_frees(spa, free_bpl, tx);
6271                 } else {
6272                         bplist_iterate(free_bpl, bpobj_enqueue_cb,
6273                             &spa->spa_deferred_bpobj, tx);
6274                 }
6275 
6276                 ddt_sync(spa, txg);
6277                 dsl_scan_sync(dp, tx);
6278 
6279                 while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
6280                         vdev_sync(vd, txg);
6281 
6282                 if (pass == 1)
6283                         spa_sync_upgrades(spa, tx);
6284 
6285         } while (dmu_objset_is_dirty(mos, txg));
6286 
6287         /*
6288          * Rewrite the vdev configuration (which includes the uberblock)
6289          * to commit the transaction group.
6290          *
6291          * If there are no dirty vdevs, we sync the uberblock to a few
6292          * random top-level vdevs that are known to be visible in the
6293          * config cache (see spa_vdev_add() for a complete description).
6294          * If there *are* dirty vdevs, sync the uberblock to all vdevs.
6295          */
6296         for (;;) {
6297                 /*
6298                  * We hold SCL_STATE to prevent vdev open/close/etc.
6299                  * while we're attempting to write the vdev labels.
6300                  */
6301                 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6302 
6303                 if (list_is_empty(&spa->spa_config_dirty_list)) {
6304                         vdev_t *svd[SPA_DVAS_PER_BP];
6305                         int svdcount = 0;
6306                         int children = rvd->vdev_children;
6307                         int c0 = spa_get_random(children);
6308 
6309                         for (int c = 0; c < children; c++) {
6310                                 vd = rvd->vdev_child[(c0 + c) % children];
6311                                 if (vd->vdev_ms_array == 0 || vd->vdev_islog)
6312                                         continue;
6313                                 svd[svdcount++] = vd;
6314                                 if (svdcount == SPA_DVAS_PER_BP)
6315                                         break;
6316                         }
6317                         error = vdev_config_sync(svd, svdcount, txg, B_FALSE);
6318                         if (error != 0)
6319                                 error = vdev_config_sync(svd, svdcount, txg,
6320                                     B_TRUE);
6321                 } else {
6322                         error = vdev_config_sync(rvd->vdev_child,
6323                             rvd->vdev_children, txg, B_FALSE);
6324                         if (error != 0)
6325                                 error = vdev_config_sync(rvd->vdev_child,
6326                                     rvd->vdev_children, txg, B_TRUE);
6327                 }
6328 
6329                 if (error == 0)
6330                         spa->spa_last_synced_guid = rvd->vdev_guid;
6331 
6332                 spa_config_exit(spa, SCL_STATE, FTAG);
6333 
6334                 if (error == 0)
6335                         break;
6336                 zio_suspend(spa, NULL);
6337                 zio_resume_wait(spa);
6338         }
6339         dmu_tx_commit(tx);
6340 
6341         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
6342 
6343         /*
6344          * Clear the dirty config list.
6345          */
6346         while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
6347                 vdev_config_clean(vd);
6348 
6349         /*
6350          * Now that the new config has synced transactionally,
6351          * let it become visible to the config cache.
6352          */
6353         if (spa->spa_config_syncing != NULL) {
6354                 spa_config_set(spa, spa->spa_config_syncing);
6355                 spa->spa_config_txg = txg;
6356                 spa->spa_config_syncing = NULL;
6357         }
6358 
6359         spa->spa_ubsync = spa->spa_uberblock;
6360 
6361         dsl_pool_sync_done(dp, txg);
6362 
6363         /*
6364          * Update usable space statistics.
6365          */
6366         while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
6367                 vdev_sync_done(vd, txg);
6368 
6369         spa_update_dspace(spa);
6370 
6371         /*
6372          * It had better be the case that we didn't dirty anything
6373          * since vdev_config_sync().
6374          */
6375         ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
6376         ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
6377         ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
6378 
6379         spa->spa_sync_pass = 0;
6380 
6381         spa_config_exit(spa, SCL_CONFIG, FTAG);
6382 
6383         spa_handle_ignored_writes(spa);
6384 
6385         /*
6386          * If any async tasks have been requested, kick them off.
6387          */
6388         spa_async_dispatch(spa);
6389 }
6390 
6391 /*
6392  * Sync all pools.  We don't want to hold the namespace lock across these
6393  * operations, so we take a reference on the spa_t and drop the lock during the
6394  * sync.
6395  */
6396 void
6397 spa_sync_allpools(void)
6398 {
6399         spa_t *spa = NULL;
6400         mutex_enter(&spa_namespace_lock);
6401         while ((spa = spa_next(spa)) != NULL) {
6402                 if (spa_state(spa) != POOL_STATE_ACTIVE ||
6403                     !spa_writeable(spa) || spa_suspended(spa))
6404                         continue;
6405                 spa_open_ref(spa, FTAG);
6406                 mutex_exit(&spa_namespace_lock);
6407                 txg_wait_synced(spa_get_dsl(spa), 0);
6408                 mutex_enter(&spa_namespace_lock);
6409                 spa_close(spa, FTAG);
6410         }
6411         mutex_exit(&spa_namespace_lock);
6412 }
6413 
6414 /*
6415  * ==========================================================================
6416  * Miscellaneous routines
6417  * ==========================================================================
6418  */
6419 
6420 /*
6421  * Remove all pools in the system.
6422  */
6423 void
6424 spa_evict_all(void)
6425 {
6426         spa_t *spa;
6427 
6428         /*
6429          * Remove all cached state.  All pools should be closed now,
6430          * so every spa in the AVL tree should be unreferenced.
6431          */
6432         mutex_enter(&spa_namespace_lock);
6433         while ((spa = spa_next(NULL)) != NULL) {
6434                 /*
6435                  * Stop async tasks.  The async thread may need to detach
6436                  * a device that's been replaced, which requires grabbing
6437                  * spa_namespace_lock, so we must drop it here.
6438                  */
6439                 spa_open_ref(spa, FTAG);
6440                 mutex_exit(&spa_namespace_lock);
6441                 spa_async_suspend(spa);
6442                 mutex_enter(&spa_namespace_lock);
6443                 spa_close(spa, FTAG);
6444 
6445                 if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
6446                         spa_unload(spa);
6447                         spa_deactivate(spa);
6448                 }
6449                 spa_remove(spa);
6450         }
6451         mutex_exit(&spa_namespace_lock);
6452 }
6453 
6454 vdev_t *
6455 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
6456 {
6457         vdev_t *vd;
6458         int i;
6459 
6460         if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
6461                 return (vd);
6462 
6463         if (aux) {
6464                 for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
6465                         vd = spa->spa_l2cache.sav_vdevs[i];
6466                         if (vd->vdev_guid == guid)
6467                                 return (vd);
6468                 }
6469 
6470                 for (i = 0; i < spa->spa_spares.sav_count; i++) {
6471                         vd = spa->spa_spares.sav_vdevs[i];
6472                         if (vd->vdev_guid == guid)
6473                                 return (vd);
6474                 }
6475         }
6476 
6477         return (NULL);
6478 }
6479 
6480 void
6481 spa_upgrade(spa_t *spa, uint64_t version)
6482 {
6483         ASSERT(spa_writeable(spa));
6484 
6485         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6486 
6487         /*
6488          * This should only be called for a non-faulted pool, and since a
6489          * future version would result in an unopenable pool, this shouldn't be
6490          * possible.
6491          */
6492         ASSERT(SPA_VERSION_IS_SUPPORTED(spa->spa_uberblock.ub_version));
6493         ASSERT3U(version, >=, spa->spa_uberblock.ub_version);
6494 
6495         spa->spa_uberblock.ub_version = version;
6496         vdev_config_dirty(spa->spa_root_vdev);
6497 
6498         spa_config_exit(spa, SCL_ALL, FTAG);
6499 
6500         txg_wait_synced(spa_get_dsl(spa), 0);
6501 }
6502 
6503 boolean_t
6504 spa_has_spare(spa_t *spa, uint64_t guid)
6505 {
6506         int i;
6507         uint64_t spareguid;
6508         spa_aux_vdev_t *sav = &spa->spa_spares;
6509 
6510         for (i = 0; i < sav->sav_count; i++)
6511                 if (sav->sav_vdevs[i]->vdev_guid == guid)
6512                         return (B_TRUE);
6513 
6514         for (i = 0; i < sav->sav_npending; i++) {
6515                 if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
6516                     &spareguid) == 0 && spareguid == guid)
6517                         return (B_TRUE);
6518         }
6519 
6520         return (B_FALSE);
6521 }
6522 
6523 /*
6524  * Check if a pool has an active shared spare device.
6525  * Note: reference count of an active spare is 2, as a spare and as a replace
6526  */
6527 static boolean_t
6528 spa_has_active_shared_spare(spa_t *spa)
6529 {
6530         int i, refcnt;
6531         uint64_t pool;
6532         spa_aux_vdev_t *sav = &spa->spa_spares;
6533 
6534         for (i = 0; i < sav->sav_count; i++) {
6535                 if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
6536                     &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
6537                     refcnt > 2)
6538                         return (B_TRUE);
6539         }
6540 
6541         return (B_FALSE);
6542 }
6543 
6544 /*
6545  * Post a sysevent corresponding to the given event.  The 'name' must be one of
6546  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
6547  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
6548  * in the userland libzpool, as we don't want consumers to misinterpret ztest
6549  * or zdb as real changes.
6550  */
6551 void
6552 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
6553 {
6554 #ifdef _KERNEL
6555         sysevent_t              *ev;
6556         sysevent_attr_list_t    *attr = NULL;
6557         sysevent_value_t        value;
6558         sysevent_id_t           eid;
6559 
6560         ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
6561             SE_SLEEP);
6562 
6563         value.value_type = SE_DATA_TYPE_STRING;
6564         value.value.sv_string = spa_name(spa);
6565         if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
6566                 goto done;
6567 
6568         value.value_type = SE_DATA_TYPE_UINT64;
6569         value.value.sv_uint64 = spa_guid(spa);
6570         if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
6571                 goto done;
6572 
6573         if (vd) {
6574                 value.value_type = SE_DATA_TYPE_UINT64;
6575                 value.value.sv_uint64 = vd->vdev_guid;
6576                 if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
6577                     SE_SLEEP) != 0)
6578                         goto done;
6579 
6580                 if (vd->vdev_path) {
6581                         value.value_type = SE_DATA_TYPE_STRING;
6582                         value.value.sv_string = vd->vdev_path;
6583                         if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
6584                             &value, SE_SLEEP) != 0)
6585                                 goto done;
6586                 }
6587         }
6588 
6589         if (sysevent_attach_attributes(ev, attr) != 0)
6590                 goto done;
6591         attr = NULL;
6592 
6593         (void) log_sysevent(ev, SE_SLEEP, &eid);
6594 
6595 done:
6596         if (attr)
6597                 sysevent_free_attr(attr);
6598         sysevent_free(ev);
6599 #endif
6600 }
--- EOF ---