1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright (c) 2013 by Delphix. All rights reserved.
  25  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
  26  */
  27 
  28 /*
  29  * SPA: Storage Pool Allocator
  30  *
  31  * This file contains all the routines used when modifying on-disk SPA state.
  32  * This includes opening, importing, destroying, exporting a pool, and syncing a
  33  * pool.
  34  */
  35 
  36 #include <sys/zfs_context.h>
  37 #include <sys/fm/fs/zfs.h>
  38 #include <sys/spa_impl.h>
  39 #include <sys/zio.h>
  40 #include <sys/zio_checksum.h>
  41 #include <sys/dmu.h>
  42 #include <sys/dmu_tx.h>
  43 #include <sys/zap.h>
  44 #include <sys/zil.h>
  45 #include <sys/ddt.h>
  46 #include <sys/vdev_impl.h>
  47 #include <sys/metaslab.h>
  48 #include <sys/metaslab_impl.h>
  49 #include <sys/uberblock_impl.h>
  50 #include <sys/txg.h>
  51 #include <sys/avl.h>
  52 #include <sys/dmu_traverse.h>
  53 #include <sys/dmu_objset.h>
  54 #include <sys/unique.h>
  55 #include <sys/dsl_pool.h>
  56 #include <sys/dsl_dataset.h>
  57 #include <sys/dsl_dir.h>
  58 #include <sys/dsl_prop.h>
  59 #include <sys/dsl_synctask.h>
  60 #include <sys/fs/zfs.h>
  61 #include <sys/arc.h>
  62 #include <sys/callb.h>
  63 #include <sys/systeminfo.h>
  64 #include <sys/spa_boot.h>
  65 #include <sys/zfs_ioctl.h>
  66 #include <sys/dsl_scan.h>
  67 #include <sys/zfeature.h>
  68 #include <sys/dsl_destroy.h>
  69 
  70 #ifdef  _KERNEL
  71 #include <sys/bootprops.h>
  72 #include <sys/callb.h>
  73 #include <sys/cpupart.h>
  74 #include <sys/pool.h>
  75 #include <sys/sysdc.h>
  76 #include <sys/zone.h>
  77 #endif  /* _KERNEL */
  78 
  79 #include "zfs_prop.h"
  80 #include "zfs_comutil.h"
  81 
  82 /*
  83  * The interval, in seconds, at which failed configuration cache file writes
  84  * should be retried.
  85  */
  86 static int zfs_ccw_retry_interval = 300;
  87 
  88 typedef enum zti_modes {
  89         ZTI_MODE_FIXED,                 /* value is # of threads (min 1) */
  90         ZTI_MODE_ONLINE_PERCENT,        /* value is % of online CPUs */
  91         ZTI_MODE_BATCH,                 /* cpu-intensive; value is ignored */
  92         ZTI_MODE_NULL,                  /* don't create a taskq */
  93         ZTI_NMODES
  94 } zti_modes_t;
  95 
  96 #define ZTI_P(n, q)     { ZTI_MODE_FIXED, (n), (q) }
  97 #define ZTI_PCT(n)      { ZTI_MODE_ONLINE_PERCENT, (n), 1 }
  98 #define ZTI_BATCH       { ZTI_MODE_BATCH, 0, 1 }
  99 #define ZTI_NULL        { ZTI_MODE_NULL, 0, 0 }
 100 
 101 #define ZTI_N(n)        ZTI_P(n, 1)
 102 #define ZTI_ONE         ZTI_N(1)
 103 
 104 typedef struct zio_taskq_info {
 105         zti_modes_t zti_mode;
 106         uint_t zti_value;
 107         uint_t zti_count;
 108 } zio_taskq_info_t;
 109 
 110 static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
 111         "issue", "issue_high", "intr", "intr_high"
 112 };
 113 
 114 /*
 115  * This table defines the taskq settings for each ZFS I/O type. When
 116  * initializing a pool, we use this table to create an appropriately sized
 117  * taskq. Some operations are low volume and therefore have a small, static
 118  * number of threads assigned to their taskqs using the ZTI_N(#) or ZTI_ONE
 119  * macros. Other operations process a large amount of data; the ZTI_BATCH
 120  * macro causes us to create a taskq oriented for throughput. Some operations
 121  * are so high frequency and short-lived that the taskq itself can become a a
 122  * point of lock contention. The ZTI_P(#, #) macro indicates that we need an
 123  * additional degree of parallelism specified by the number of threads per-
 124  * taskq and the number of taskqs; when dispatching an event in this case, the
 125  * particular taskq is chosen at random.
 126  *
 127  * The different taskq priorities are to handle the different contexts (issue
 128  * and interrupt) and then to reserve threads for ZIO_PRIORITY_NOW I/Os that
 129  * need to be handled with minimum delay.
 130  */
 131 const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
 132         /* ISSUE        ISSUE_HIGH      INTR            INTR_HIGH */
 133         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* NULL */
 134         { ZTI_N(8),     ZTI_NULL,       ZTI_BATCH,      ZTI_NULL }, /* READ */
 135         { ZTI_BATCH,    ZTI_N(5),       ZTI_N(8),       ZTI_N(5) }, /* WRITE */
 136         { ZTI_P(12, 8), ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* FREE */
 137         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* CLAIM */
 138         { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* IOCTL */
 139 };
 140 
 141 static void spa_sync_version(void *arg, dmu_tx_t *tx);
 142 static void spa_sync_props(void *arg, dmu_tx_t *tx);
 143 static boolean_t spa_has_active_shared_spare(spa_t *spa);
 144 static int spa_load_impl(spa_t *spa, uint64_t, nvlist_t *config,
 145     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
 146     char **ereport);
 147 static void spa_vdev_resilver_done(spa_t *spa);
 148 
 149 uint_t          zio_taskq_batch_pct = 100;      /* 1 thread per cpu in pset */
 150 id_t            zio_taskq_psrset_bind = PS_NONE;
 151 boolean_t       zio_taskq_sysdc = B_TRUE;       /* use SDC scheduling class */
 152 uint_t          zio_taskq_basedc = 80;          /* base duty cycle */
 153 
 154 boolean_t       spa_create_process = B_TRUE;    /* no process ==> no sysdc */
 155 extern int      zfs_sync_pass_deferred_free;
 156 
 157 /*
 158  * This (illegal) pool name is used when temporarily importing a spa_t in order
 159  * to get the vdev stats associated with the imported devices.
 160  */
 161 #define TRYIMPORT_NAME  "$import"
 162 
 163 /*
 164  * ==========================================================================
 165  * SPA properties routines
 166  * ==========================================================================
 167  */
 168 
 169 /*
 170  * Add a (source=src, propname=propval) list to an nvlist.
 171  */
 172 static void
 173 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, char *strval,
 174     uint64_t intval, zprop_source_t src)
 175 {
 176         const char *propname = zpool_prop_to_name(prop);
 177         nvlist_t *propval;
 178 
 179         VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 180         VERIFY(nvlist_add_uint64(propval, ZPROP_SOURCE, src) == 0);
 181 
 182         if (strval != NULL)
 183                 VERIFY(nvlist_add_string(propval, ZPROP_VALUE, strval) == 0);
 184         else
 185                 VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, intval) == 0);
 186 
 187         VERIFY(nvlist_add_nvlist(nvl, propname, propval) == 0);
 188         nvlist_free(propval);
 189 }
 190 
 191 /*
 192  * Get property values from the spa configuration.
 193  */
 194 static void
 195 spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
 196 {
 197         vdev_t *rvd = spa->spa_root_vdev;
 198         dsl_pool_t *pool = spa->spa_dsl_pool;
 199         uint64_t size;
 200         uint64_t alloc;
 201         uint64_t space;
 202         uint64_t cap, version;
 203         zprop_source_t src = ZPROP_SRC_NONE;
 204         spa_config_dirent_t *dp;
 205 
 206         ASSERT(MUTEX_HELD(&spa->spa_props_lock));
 207 
 208         if (rvd != NULL) {
 209                 alloc = metaslab_class_get_alloc(spa_normal_class(spa));
 210                 size = metaslab_class_get_space(spa_normal_class(spa));
 211                 spa_prop_add_list(*nvp, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
 212                 spa_prop_add_list(*nvp, ZPOOL_PROP_SIZE, NULL, size, src);
 213                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALLOCATED, NULL, alloc, src);
 214                 spa_prop_add_list(*nvp, ZPOOL_PROP_FREE, NULL,
 215                     size - alloc, src);
 216 
 217                 space = 0;
 218                 for (int c = 0; c < rvd->vdev_children; c++) {
 219                         vdev_t *tvd = rvd->vdev_child[c];
 220                         space += tvd->vdev_max_asize - tvd->vdev_asize;
 221                 }
 222                 spa_prop_add_list(*nvp, ZPOOL_PROP_EXPANDSZ, NULL, space,
 223                     src);
 224 
 225                 spa_prop_add_list(*nvp, ZPOOL_PROP_READONLY, NULL,
 226                     (spa_mode(spa) == FREAD), src);
 227 
 228                 cap = (size == 0) ? 0 : (alloc * 100 / size);
 229                 spa_prop_add_list(*nvp, ZPOOL_PROP_CAPACITY, NULL, cap, src);
 230 
 231                 spa_prop_add_list(*nvp, ZPOOL_PROP_DEDUPRATIO, NULL,
 232                     ddt_get_pool_dedup_ratio(spa), src);
 233 
 234                 spa_prop_add_list(*nvp, ZPOOL_PROP_HEALTH, NULL,
 235                     rvd->vdev_state, src);
 236 
 237                 version = spa_version(spa);
 238                 if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION))
 239                         src = ZPROP_SRC_DEFAULT;
 240                 else
 241                         src = ZPROP_SRC_LOCAL;
 242                 spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL, version, src);
 243         }
 244 
 245         if (pool != NULL) {
 246                 dsl_dir_t *freedir = pool->dp_free_dir;
 247 
 248                 /*
 249                  * The $FREE directory was introduced in SPA_VERSION_DEADLISTS,
 250                  * when opening pools before this version freedir will be NULL.
 251                  */
 252                 if (freedir != NULL) {
 253                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING, NULL,
 254                             freedir->dd_phys->dd_used_bytes, src);
 255                 } else {
 256                         spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING,
 257                             NULL, 0, src);
 258                 }
 259         }
 260 
 261         spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
 262 
 263         if (spa->spa_comment != NULL) {
 264                 spa_prop_add_list(*nvp, ZPOOL_PROP_COMMENT, spa->spa_comment,
 265                     0, ZPROP_SRC_LOCAL);
 266         }
 267 
 268         if (spa->spa_root != NULL)
 269                 spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
 270                     0, ZPROP_SRC_LOCAL);
 271 
 272         if ((dp = list_head(&spa->spa_config_list)) != NULL) {
 273                 if (dp->scd_path == NULL) {
 274                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 275                             "none", 0, ZPROP_SRC_LOCAL);
 276                 } else if (strcmp(dp->scd_path, spa_config_path) != 0) {
 277                         spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
 278                             dp->scd_path, 0, ZPROP_SRC_LOCAL);
 279                 }
 280         }
 281 }
 282 
 283 /*
 284  * Get zpool property values.
 285  */
 286 int
 287 spa_prop_get(spa_t *spa, nvlist_t **nvp)
 288 {
 289         objset_t *mos = spa->spa_meta_objset;
 290         zap_cursor_t zc;
 291         zap_attribute_t za;
 292         int err;
 293 
 294         VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 295 
 296         mutex_enter(&spa->spa_props_lock);
 297 
 298         /*
 299          * Get properties from the spa config.
 300          */
 301         spa_prop_get_config(spa, nvp);
 302 
 303         /* If no pool property object, no more prop to get. */
 304         if (mos == NULL || spa->spa_pool_props_object == 0) {
 305                 mutex_exit(&spa->spa_props_lock);
 306                 return (0);
 307         }
 308 
 309         /*
 310          * Get properties from the MOS pool property object.
 311          */
 312         for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
 313             (err = zap_cursor_retrieve(&zc, &za)) == 0;
 314             zap_cursor_advance(&zc)) {
 315                 uint64_t intval = 0;
 316                 char *strval = NULL;
 317                 zprop_source_t src = ZPROP_SRC_DEFAULT;
 318                 zpool_prop_t prop;
 319 
 320                 if ((prop = zpool_name_to_prop(za.za_name)) == ZPROP_INVAL)
 321                         continue;
 322 
 323                 switch (za.za_integer_length) {
 324                 case 8:
 325                         /* integer property */
 326                         if (za.za_first_integer !=
 327                             zpool_prop_default_numeric(prop))
 328                                 src = ZPROP_SRC_LOCAL;
 329 
 330                         if (prop == ZPOOL_PROP_BOOTFS) {
 331                                 dsl_pool_t *dp;
 332                                 dsl_dataset_t *ds = NULL;
 333 
 334                                 dp = spa_get_dsl(spa);
 335                                 dsl_pool_config_enter(dp, FTAG);
 336                                 if (err = dsl_dataset_hold_obj(dp,
 337                                     za.za_first_integer, FTAG, &ds)) {
 338                                         dsl_pool_config_exit(dp, FTAG);
 339                                         break;
 340                                 }
 341 
 342                                 strval = kmem_alloc(
 343                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1,
 344                                     KM_SLEEP);
 345                                 dsl_dataset_name(ds, strval);
 346                                 dsl_dataset_rele(ds, FTAG);
 347                                 dsl_pool_config_exit(dp, FTAG);
 348                         } else {
 349                                 strval = NULL;
 350                                 intval = za.za_first_integer;
 351                         }
 352 
 353                         spa_prop_add_list(*nvp, prop, strval, intval, src);
 354 
 355                         if (strval != NULL)
 356                                 kmem_free(strval,
 357                                     MAXNAMELEN + strlen(MOS_DIR_NAME) + 1);
 358 
 359                         break;
 360 
 361                 case 1:
 362                         /* string property */
 363                         strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
 364                         err = zap_lookup(mos, spa->spa_pool_props_object,
 365                             za.za_name, 1, za.za_num_integers, strval);
 366                         if (err) {
 367                                 kmem_free(strval, za.za_num_integers);
 368                                 break;
 369                         }
 370                         spa_prop_add_list(*nvp, prop, strval, 0, src);
 371                         kmem_free(strval, za.za_num_integers);
 372                         break;
 373 
 374                 default:
 375                         break;
 376                 }
 377         }
 378         zap_cursor_fini(&zc);
 379         mutex_exit(&spa->spa_props_lock);
 380 out:
 381         if (err && err != ENOENT) {
 382                 nvlist_free(*nvp);
 383                 *nvp = NULL;
 384                 return (err);
 385         }
 386 
 387         return (0);
 388 }
 389 
 390 /*
 391  * Validate the given pool properties nvlist and modify the list
 392  * for the property values to be set.
 393  */
 394 static int
 395 spa_prop_validate(spa_t *spa, nvlist_t *props)
 396 {
 397         nvpair_t *elem;
 398         int error = 0, reset_bootfs = 0;
 399         uint64_t objnum = 0;
 400         boolean_t has_feature = B_FALSE;
 401 
 402         elem = NULL;
 403         while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
 404                 uint64_t intval;
 405                 char *strval, *slash, *check, *fname;
 406                 const char *propname = nvpair_name(elem);
 407                 zpool_prop_t prop = zpool_name_to_prop(propname);
 408 
 409                 switch (prop) {
 410                 case ZPROP_INVAL:
 411                         if (!zpool_prop_feature(propname)) {
 412                                 error = SET_ERROR(EINVAL);
 413                                 break;
 414                         }
 415 
 416                         /*
 417                          * Sanitize the input.
 418                          */
 419                         if (nvpair_type(elem) != DATA_TYPE_UINT64) {
 420                                 error = SET_ERROR(EINVAL);
 421                                 break;
 422                         }
 423 
 424                         if (nvpair_value_uint64(elem, &intval) != 0) {
 425                                 error = SET_ERROR(EINVAL);
 426                                 break;
 427                         }
 428 
 429                         if (intval != 0) {
 430                                 error = SET_ERROR(EINVAL);
 431                                 break;
 432                         }
 433 
 434                         fname = strchr(propname, '@') + 1;
 435                         if (zfeature_lookup_name(fname, NULL) != 0) {
 436                                 error = SET_ERROR(EINVAL);
 437                                 break;
 438                         }
 439 
 440                         has_feature = B_TRUE;
 441                         break;
 442 
 443                 case ZPOOL_PROP_VERSION:
 444                         error = nvpair_value_uint64(elem, &intval);
 445                         if (!error &&
 446                             (intval < spa_version(spa) ||
 447                             intval > SPA_VERSION_BEFORE_FEATURES ||
 448                             has_feature))
 449                                 error = SET_ERROR(EINVAL);
 450                         break;
 451 
 452                 case ZPOOL_PROP_DELEGATION:
 453                 case ZPOOL_PROP_AUTOREPLACE:
 454                 case ZPOOL_PROP_LISTSNAPS:
 455                 case ZPOOL_PROP_AUTOEXPAND:
 456                         error = nvpair_value_uint64(elem, &intval);
 457                         if (!error && intval > 1)
 458                                 error = SET_ERROR(EINVAL);
 459                         break;
 460 
 461                 case ZPOOL_PROP_BOOTFS:
 462                         /*
 463                          * If the pool version is less than SPA_VERSION_BOOTFS,
 464                          * or the pool is still being created (version == 0),
 465                          * the bootfs property cannot be set.
 466                          */
 467                         if (spa_version(spa) < SPA_VERSION_BOOTFS) {
 468                                 error = SET_ERROR(ENOTSUP);
 469                                 break;
 470                         }
 471 
 472                         /*
 473                          * Make sure the vdev config is bootable
 474                          */
 475                         if (!vdev_is_bootable(spa->spa_root_vdev)) {
 476                                 error = SET_ERROR(ENOTSUP);
 477                                 break;
 478                         }
 479 
 480                         reset_bootfs = 1;
 481 
 482                         error = nvpair_value_string(elem, &strval);
 483 
 484                         if (!error) {
 485                                 objset_t *os;
 486                                 uint64_t compress;
 487 
 488                                 if (strval == NULL || strval[0] == '\0') {
 489                                         objnum = zpool_prop_default_numeric(
 490                                             ZPOOL_PROP_BOOTFS);
 491                                         break;
 492                                 }
 493 
 494                                 if (error = dmu_objset_hold(strval, FTAG, &os))
 495                                         break;
 496 
 497                                 /* Must be ZPL and not gzip compressed. */
 498 
 499                                 if (dmu_objset_type(os) != DMU_OST_ZFS) {
 500                                         error = SET_ERROR(ENOTSUP);
 501                                 } else if ((error =
 502                                     dsl_prop_get_int_ds(dmu_objset_ds(os),
 503                                     zfs_prop_to_name(ZFS_PROP_COMPRESSION),
 504                                     &compress)) == 0 &&
 505                                     !BOOTFS_COMPRESS_VALID(compress)) {
 506                                         error = SET_ERROR(ENOTSUP);
 507                                 } else {
 508                                         objnum = dmu_objset_id(os);
 509                                 }
 510                                 dmu_objset_rele(os, FTAG);
 511                         }
 512                         break;
 513 
 514                 case ZPOOL_PROP_FAILUREMODE:
 515                         error = nvpair_value_uint64(elem, &intval);
 516                         if (!error && (intval < ZIO_FAILURE_MODE_WAIT ||
 517                             intval > ZIO_FAILURE_MODE_PANIC))
 518                                 error = SET_ERROR(EINVAL);
 519 
 520                         /*
 521                          * This is a special case which only occurs when
 522                          * the pool has completely failed. This allows
 523                          * the user to change the in-core failmode property
 524                          * without syncing it out to disk (I/Os might
 525                          * currently be blocked). We do this by returning
 526                          * EIO to the caller (spa_prop_set) to trick it
 527                          * into thinking we encountered a property validation
 528                          * error.
 529                          */
 530                         if (!error && spa_suspended(spa)) {
 531                                 spa->spa_failmode = intval;
 532                                 error = SET_ERROR(EIO);
 533                         }
 534                         break;
 535 
 536                 case ZPOOL_PROP_CACHEFILE:
 537                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 538                                 break;
 539 
 540                         if (strval[0] == '\0')
 541                                 break;
 542 
 543                         if (strcmp(strval, "none") == 0)
 544                                 break;
 545 
 546                         if (strval[0] != '/') {
 547                                 error = SET_ERROR(EINVAL);
 548                                 break;
 549                         }
 550 
 551                         slash = strrchr(strval, '/');
 552                         ASSERT(slash != NULL);
 553 
 554                         if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
 555                             strcmp(slash, "/..") == 0)
 556                                 error = SET_ERROR(EINVAL);
 557                         break;
 558 
 559                 case ZPOOL_PROP_COMMENT:
 560                         if ((error = nvpair_value_string(elem, &strval)) != 0)
 561                                 break;
 562                         for (check = strval; *check != '\0'; check++) {
 563                                 /*
 564                                  * The kernel doesn't have an easy isprint()
 565                                  * check.  For this kernel check, we merely
 566                                  * check ASCII apart from DEL.  Fix this if
 567                                  * there is an easy-to-use kernel isprint().
 568                                  */
 569                                 if (*check >= 0x7f) {
 570                                         error = SET_ERROR(EINVAL);
 571                                         break;
 572                                 }
 573                                 check++;
 574                         }
 575                         if (strlen(strval) > ZPROP_MAX_COMMENT)
 576                                 error = E2BIG;
 577                         break;
 578 
 579                 case ZPOOL_PROP_DEDUPDITTO:
 580                         if (spa_version(spa) < SPA_VERSION_DEDUP)
 581                                 error = SET_ERROR(ENOTSUP);
 582                         else
 583                                 error = nvpair_value_uint64(elem, &intval);
 584                         if (error == 0 &&
 585                             intval != 0 && intval < ZIO_DEDUPDITTO_MIN)
 586                                 error = SET_ERROR(EINVAL);
 587                         break;
 588                 }
 589 
 590                 if (error)
 591                         break;
 592         }
 593 
 594         if (!error && reset_bootfs) {
 595                 error = nvlist_remove(props,
 596                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
 597 
 598                 if (!error) {
 599                         error = nvlist_add_uint64(props,
 600                             zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
 601                 }
 602         }
 603 
 604         return (error);
 605 }
 606 
 607 void
 608 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
 609 {
 610         char *cachefile;
 611         spa_config_dirent_t *dp;
 612 
 613         if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
 614             &cachefile) != 0)
 615                 return;
 616 
 617         dp = kmem_alloc(sizeof (spa_config_dirent_t),
 618             KM_SLEEP);
 619 
 620         if (cachefile[0] == '\0')
 621                 dp->scd_path = spa_strdup(spa_config_path);
 622         else if (strcmp(cachefile, "none") == 0)
 623                 dp->scd_path = NULL;
 624         else
 625                 dp->scd_path = spa_strdup(cachefile);
 626 
 627         list_insert_head(&spa->spa_config_list, dp);
 628         if (need_sync)
 629                 spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
 630 }
 631 
 632 int
 633 spa_prop_set(spa_t *spa, nvlist_t *nvp)
 634 {
 635         int error;
 636         nvpair_t *elem = NULL;
 637         boolean_t need_sync = B_FALSE;
 638 
 639         if ((error = spa_prop_validate(spa, nvp)) != 0)
 640                 return (error);
 641 
 642         while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
 643                 zpool_prop_t prop = zpool_name_to_prop(nvpair_name(elem));
 644 
 645                 if (prop == ZPOOL_PROP_CACHEFILE ||
 646                     prop == ZPOOL_PROP_ALTROOT ||
 647                     prop == ZPOOL_PROP_READONLY)
 648                         continue;
 649 
 650                 if (prop == ZPOOL_PROP_VERSION || prop == ZPROP_INVAL) {
 651                         uint64_t ver;
 652 
 653                         if (prop == ZPOOL_PROP_VERSION) {
 654                                 VERIFY(nvpair_value_uint64(elem, &ver) == 0);
 655                         } else {
 656                                 ASSERT(zpool_prop_feature(nvpair_name(elem)));
 657                                 ver = SPA_VERSION_FEATURES;
 658                                 need_sync = B_TRUE;
 659                         }
 660 
 661                         /* Save time if the version is already set. */
 662                         if (ver == spa_version(spa))
 663                                 continue;
 664 
 665                         /*
 666                          * In addition to the pool directory object, we might
 667                          * create the pool properties object, the features for
 668                          * read object, the features for write object, or the
 669                          * feature descriptions object.
 670                          */
 671                         error = dsl_sync_task(spa->spa_name, NULL,
 672                             spa_sync_version, &ver, 6);
 673                         if (error)
 674                                 return (error);
 675                         continue;
 676                 }
 677 
 678                 need_sync = B_TRUE;
 679                 break;
 680         }
 681 
 682         if (need_sync) {
 683                 return (dsl_sync_task(spa->spa_name, NULL, spa_sync_props,
 684                     nvp, 6));
 685         }
 686 
 687         return (0);
 688 }
 689 
 690 /*
 691  * If the bootfs property value is dsobj, clear it.
 692  */
 693 void
 694 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
 695 {
 696         if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
 697                 VERIFY(zap_remove(spa->spa_meta_objset,
 698                     spa->spa_pool_props_object,
 699                     zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
 700                 spa->spa_bootfs = 0;
 701         }
 702 }
 703 
 704 /*ARGSUSED*/
 705 static int
 706 spa_change_guid_check(void *arg, dmu_tx_t *tx)
 707 {
 708         uint64_t *newguid = arg;
 709         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 710         vdev_t *rvd = spa->spa_root_vdev;
 711         uint64_t vdev_state;
 712 
 713         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
 714         vdev_state = rvd->vdev_state;
 715         spa_config_exit(spa, SCL_STATE, FTAG);
 716 
 717         if (vdev_state != VDEV_STATE_HEALTHY)
 718                 return (SET_ERROR(ENXIO));
 719 
 720         ASSERT3U(spa_guid(spa), !=, *newguid);
 721 
 722         return (0);
 723 }
 724 
 725 static void
 726 spa_change_guid_sync(void *arg, dmu_tx_t *tx)
 727 {
 728         uint64_t *newguid = arg;
 729         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 730         uint64_t oldguid;
 731         vdev_t *rvd = spa->spa_root_vdev;
 732 
 733         oldguid = spa_guid(spa);
 734 
 735         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
 736         rvd->vdev_guid = *newguid;
 737         rvd->vdev_guid_sum += (*newguid - oldguid);
 738         vdev_config_dirty(rvd);
 739         spa_config_exit(spa, SCL_STATE, FTAG);
 740 
 741         spa_history_log_internal(spa, "guid change", tx, "old=%llu new=%llu",
 742             oldguid, *newguid);
 743 }
 744 
 745 /*
 746  * Change the GUID for the pool.  This is done so that we can later
 747  * re-import a pool built from a clone of our own vdevs.  We will modify
 748  * the root vdev's guid, our own pool guid, and then mark all of our
 749  * vdevs dirty.  Note that we must make sure that all our vdevs are
 750  * online when we do this, or else any vdevs that weren't present
 751  * would be orphaned from our pool.  We are also going to issue a
 752  * sysevent to update any watchers.
 753  */
 754 int
 755 spa_change_guid(spa_t *spa)
 756 {
 757         int error;
 758         uint64_t guid;
 759 
 760         mutex_enter(&spa_namespace_lock);
 761         guid = spa_generate_guid(NULL);
 762 
 763         error = dsl_sync_task(spa->spa_name, spa_change_guid_check,
 764             spa_change_guid_sync, &guid, 5);
 765 
 766         if (error == 0) {
 767                 spa_config_sync(spa, B_FALSE, B_TRUE);
 768                 spa_event_notify(spa, NULL, ESC_ZFS_POOL_REGUID);
 769         }
 770 
 771         mutex_exit(&spa_namespace_lock);
 772 
 773         return (error);
 774 }
 775 
 776 /*
 777  * ==========================================================================
 778  * SPA state manipulation (open/create/destroy/import/export)
 779  * ==========================================================================
 780  */
 781 
 782 static int
 783 spa_error_entry_compare(const void *a, const void *b)
 784 {
 785         spa_error_entry_t *sa = (spa_error_entry_t *)a;
 786         spa_error_entry_t *sb = (spa_error_entry_t *)b;
 787         int ret;
 788 
 789         ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
 790             sizeof (zbookmark_t));
 791 
 792         if (ret < 0)
 793                 return (-1);
 794         else if (ret > 0)
 795                 return (1);
 796         else
 797                 return (0);
 798 }
 799 
 800 /*
 801  * Utility function which retrieves copies of the current logs and
 802  * re-initializes them in the process.
 803  */
 804 void
 805 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
 806 {
 807         ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
 808 
 809         bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
 810         bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));
 811 
 812         avl_create(&spa->spa_errlist_scrub,
 813             spa_error_entry_compare, sizeof (spa_error_entry_t),
 814             offsetof(spa_error_entry_t, se_avl));
 815         avl_create(&spa->spa_errlist_last,
 816             spa_error_entry_compare, sizeof (spa_error_entry_t),
 817             offsetof(spa_error_entry_t, se_avl));
 818 }
 819 
 820 static void
 821 spa_taskqs_init(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
 822 {
 823         const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
 824         enum zti_modes mode = ztip->zti_mode;
 825         uint_t value = ztip->zti_value;
 826         uint_t count = ztip->zti_count;
 827         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 828         char name[32];
 829         uint_t flags = 0;
 830         boolean_t batch = B_FALSE;
 831 
 832         if (mode == ZTI_MODE_NULL) {
 833                 tqs->stqs_count = 0;
 834                 tqs->stqs_taskq = NULL;
 835                 return;
 836         }
 837 
 838         ASSERT3U(count, >, 0);
 839 
 840         tqs->stqs_count = count;
 841         tqs->stqs_taskq = kmem_alloc(count * sizeof (taskq_t *), KM_SLEEP);
 842 
 843         for (uint_t i = 0; i < count; i++) {
 844                 taskq_t *tq;
 845 
 846                 switch (mode) {
 847                 case ZTI_MODE_FIXED:
 848                         ASSERT3U(value, >=, 1);
 849                         value = MAX(value, 1);
 850                         break;
 851 
 852                 case ZTI_MODE_BATCH:
 853                         batch = B_TRUE;
 854                         flags |= TASKQ_THREADS_CPU_PCT;
 855                         value = zio_taskq_batch_pct;
 856                         break;
 857 
 858                 case ZTI_MODE_ONLINE_PERCENT:
 859                         flags |= TASKQ_THREADS_CPU_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                 if (count > 1) {
 870                         (void) snprintf(name, sizeof (name), "%s_%s_%u",
 871                             zio_type_name[t], zio_taskq_types[q], i);
 872                 } else {
 873                         (void) snprintf(name, sizeof (name), "%s_%s",
 874                             zio_type_name[t], zio_taskq_types[q]);
 875                 }
 876 
 877                 if (zio_taskq_sysdc && spa->spa_proc != &p0) {
 878                         if (batch)
 879                                 flags |= TASKQ_DC_BATCH;
 880 
 881                         tq = taskq_create_sysdc(name, value, 50, INT_MAX,
 882                             spa->spa_proc, zio_taskq_basedc, flags);
 883                 } else {
 884                         tq = taskq_create_proc(name, value, maxclsyspri, 50,
 885                             INT_MAX, spa->spa_proc, flags);
 886                 }
 887 
 888                 tqs->stqs_taskq[i] = tq;
 889         }
 890 }
 891 
 892 static void
 893 spa_taskqs_fini(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
 894 {
 895         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 896 
 897         if (tqs->stqs_taskq == NULL) {
 898                 ASSERT0(tqs->stqs_count);
 899                 return;
 900         }
 901 
 902         for (uint_t i = 0; i < tqs->stqs_count; i++) {
 903                 ASSERT3P(tqs->stqs_taskq[i], !=, NULL);
 904                 taskq_destroy(tqs->stqs_taskq[i]);
 905         }
 906 
 907         kmem_free(tqs->stqs_taskq, tqs->stqs_count * sizeof (taskq_t *));
 908         tqs->stqs_taskq = NULL;
 909 }
 910 
 911 /*
 912  * Dispatch a task to the appropriate taskq for the ZFS I/O type and priority.
 913  * Note that a type may have multiple discrete taskqs to avoid lock contention
 914  * on the taskq itself. In that case we choose which taskq at random by using
 915  * the low bits of gethrtime().
 916  */
 917 void
 918 spa_taskq_dispatch_ent(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
 919     task_func_t *func, void *arg, uint_t flags, taskq_ent_t *ent)
 920 {
 921         spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
 922         taskq_t *tq;
 923 
 924         ASSERT3P(tqs->stqs_taskq, !=, NULL);
 925         ASSERT3U(tqs->stqs_count, !=, 0);
 926 
 927         if (tqs->stqs_count == 1) {
 928                 tq = tqs->stqs_taskq[0];
 929         } else {
 930                 tq = tqs->stqs_taskq[gethrtime() % tqs->stqs_count];
 931         }
 932 
 933         taskq_dispatch_ent(tq, func, arg, flags, ent);
 934 }
 935 
 936 static void
 937 spa_create_zio_taskqs(spa_t *spa)
 938 {
 939         for (int t = 0; t < ZIO_TYPES; t++) {
 940                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
 941                         spa_taskqs_init(spa, t, q);
 942                 }
 943         }
 944 }
 945 
 946 #ifdef _KERNEL
 947 static void
 948 spa_thread(void *arg)
 949 {
 950         callb_cpr_t cprinfo;
 951 
 952         spa_t *spa = arg;
 953         user_t *pu = PTOU(curproc);
 954 
 955         CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
 956             spa->spa_name);
 957 
 958         ASSERT(curproc != &p0);
 959         (void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
 960             "zpool-%s", spa->spa_name);
 961         (void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
 962 
 963         /* bind this thread to the requested psrset */
 964         if (zio_taskq_psrset_bind != PS_NONE) {
 965                 pool_lock();
 966                 mutex_enter(&cpu_lock);
 967                 mutex_enter(&pidlock);
 968                 mutex_enter(&curproc->p_lock);
 969 
 970                 if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
 971                     0, NULL, NULL) == 0)  {
 972                         curthread->t_bind_pset = zio_taskq_psrset_bind;
 973                 } else {
 974                         cmn_err(CE_WARN,
 975                             "Couldn't bind process for zfs pool \"%s\" to "
 976                             "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
 977                 }
 978 
 979                 mutex_exit(&curproc->p_lock);
 980                 mutex_exit(&pidlock);
 981                 mutex_exit(&cpu_lock);
 982                 pool_unlock();
 983         }
 984 
 985         if (zio_taskq_sysdc) {
 986                 sysdc_thread_enter(curthread, 100, 0);
 987         }
 988 
 989         spa->spa_proc = curproc;
 990         spa->spa_did = curthread->t_did;
 991 
 992         spa_create_zio_taskqs(spa);
 993 
 994         mutex_enter(&spa->spa_proc_lock);
 995         ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
 996 
 997         spa->spa_proc_state = SPA_PROC_ACTIVE;
 998         cv_broadcast(&spa->spa_proc_cv);
 999 
1000         CALLB_CPR_SAFE_BEGIN(&cprinfo);
1001         while (spa->spa_proc_state == SPA_PROC_ACTIVE)
1002                 cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1003         CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
1004 
1005         ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
1006         spa->spa_proc_state = SPA_PROC_GONE;
1007         spa->spa_proc = &p0;
1008         cv_broadcast(&spa->spa_proc_cv);
1009         CALLB_CPR_EXIT(&cprinfo);   /* drops spa_proc_lock */
1010 
1011         mutex_enter(&curproc->p_lock);
1012         lwp_exit();
1013 }
1014 #endif
1015 
1016 /*
1017  * Activate an uninitialized pool.
1018  */
1019 static void
1020 spa_activate(spa_t *spa, int mode)
1021 {
1022         ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
1023 
1024         spa->spa_state = POOL_STATE_ACTIVE;
1025         spa->spa_mode = mode;
1026 
1027         spa->spa_normal_class = metaslab_class_create(spa, zfs_metaslab_ops);
1028         spa->spa_log_class = metaslab_class_create(spa, zfs_metaslab_ops);
1029 
1030         /* Try to create a covering process */
1031         mutex_enter(&spa->spa_proc_lock);
1032         ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
1033         ASSERT(spa->spa_proc == &p0);
1034         spa->spa_did = 0;
1035 
1036         /* Only create a process if we're going to be around a while. */
1037         if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
1038                 if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
1039                     NULL, 0) == 0) {
1040                         spa->spa_proc_state = SPA_PROC_CREATED;
1041                         while (spa->spa_proc_state == SPA_PROC_CREATED) {
1042                                 cv_wait(&spa->spa_proc_cv,
1043                                     &spa->spa_proc_lock);
1044                         }
1045                         ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1046                         ASSERT(spa->spa_proc != &p0);
1047                         ASSERT(spa->spa_did != 0);
1048                 } else {
1049 #ifdef _KERNEL
1050                         cmn_err(CE_WARN,
1051                             "Couldn't create process for zfs pool \"%s\"\n",
1052                             spa->spa_name);
1053 #endif
1054                 }
1055         }
1056         mutex_exit(&spa->spa_proc_lock);
1057 
1058         /* If we didn't create a process, we need to create our taskqs. */
1059         if (spa->spa_proc == &p0) {
1060                 spa_create_zio_taskqs(spa);
1061         }
1062 
1063         list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
1064             offsetof(vdev_t, vdev_config_dirty_node));
1065         list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
1066             offsetof(vdev_t, vdev_state_dirty_node));
1067 
1068         txg_list_create(&spa->spa_vdev_txg_list,
1069             offsetof(struct vdev, vdev_txg_node));
1070 
1071         avl_create(&spa->spa_errlist_scrub,
1072             spa_error_entry_compare, sizeof (spa_error_entry_t),
1073             offsetof(spa_error_entry_t, se_avl));
1074         avl_create(&spa->spa_errlist_last,
1075             spa_error_entry_compare, sizeof (spa_error_entry_t),
1076             offsetof(spa_error_entry_t, se_avl));
1077 }
1078 
1079 /*
1080  * Opposite of spa_activate().
1081  */
1082 static void
1083 spa_deactivate(spa_t *spa)
1084 {
1085         ASSERT(spa->spa_sync_on == B_FALSE);
1086         ASSERT(spa->spa_dsl_pool == NULL);
1087         ASSERT(spa->spa_root_vdev == NULL);
1088         ASSERT(spa->spa_async_zio_root == NULL);
1089         ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
1090 
1091         txg_list_destroy(&spa->spa_vdev_txg_list);
1092 
1093         list_destroy(&spa->spa_config_dirty_list);
1094         list_destroy(&spa->spa_state_dirty_list);
1095 
1096         for (int t = 0; t < ZIO_TYPES; t++) {
1097                 for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
1098                         spa_taskqs_fini(spa, t, q);
1099                 }
1100         }
1101 
1102         metaslab_class_destroy(spa->spa_normal_class);
1103         spa->spa_normal_class = NULL;
1104 
1105         metaslab_class_destroy(spa->spa_log_class);
1106         spa->spa_log_class = NULL;
1107 
1108         /*
1109          * If this was part of an import or the open otherwise failed, we may
1110          * still have errors left in the queues.  Empty them just in case.
1111          */
1112         spa_errlog_drain(spa);
1113 
1114         avl_destroy(&spa->spa_errlist_scrub);
1115         avl_destroy(&spa->spa_errlist_last);
1116 
1117         spa->spa_state = POOL_STATE_UNINITIALIZED;
1118 
1119         mutex_enter(&spa->spa_proc_lock);
1120         if (spa->spa_proc_state != SPA_PROC_NONE) {
1121                 ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1122                 spa->spa_proc_state = SPA_PROC_DEACTIVATE;
1123                 cv_broadcast(&spa->spa_proc_cv);
1124                 while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
1125                         ASSERT(spa->spa_proc != &p0);
1126                         cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1127                 }
1128                 ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
1129                 spa->spa_proc_state = SPA_PROC_NONE;
1130         }
1131         ASSERT(spa->spa_proc == &p0);
1132         mutex_exit(&spa->spa_proc_lock);
1133 
1134         /*
1135          * We want to make sure spa_thread() has actually exited the ZFS
1136          * module, so that the module can't be unloaded out from underneath
1137          * it.
1138          */
1139         if (spa->spa_did != 0) {
1140                 thread_join(spa->spa_did);
1141                 spa->spa_did = 0;
1142         }
1143 }
1144 
1145 /*
1146  * Verify a pool configuration, and construct the vdev tree appropriately.  This
1147  * will create all the necessary vdevs in the appropriate layout, with each vdev
1148  * in the CLOSED state.  This will prep the pool before open/creation/import.
1149  * All vdev validation is done by the vdev_alloc() routine.
1150  */
1151 static int
1152 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
1153     uint_t id, int atype)
1154 {
1155         nvlist_t **child;
1156         uint_t children;
1157         int error;
1158 
1159         if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
1160                 return (error);
1161 
1162         if ((*vdp)->vdev_ops->vdev_op_leaf)
1163                 return (0);
1164 
1165         error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
1166             &child, &children);
1167 
1168         if (error == ENOENT)
1169                 return (0);
1170 
1171         if (error) {
1172                 vdev_free(*vdp);
1173                 *vdp = NULL;
1174                 return (SET_ERROR(EINVAL));
1175         }
1176 
1177         for (int c = 0; c < children; c++) {
1178                 vdev_t *vd;
1179                 if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
1180                     atype)) != 0) {
1181                         vdev_free(*vdp);
1182                         *vdp = NULL;
1183                         return (error);
1184                 }
1185         }
1186 
1187         ASSERT(*vdp != NULL);
1188 
1189         return (0);
1190 }
1191 
1192 /*
1193  * Opposite of spa_load().
1194  */
1195 static void
1196 spa_unload(spa_t *spa)
1197 {
1198         int i;
1199 
1200         ASSERT(MUTEX_HELD(&spa_namespace_lock));
1201 
1202         /*
1203          * Stop async tasks.
1204          */
1205         spa_async_suspend(spa);
1206 
1207         /*
1208          * Stop syncing.
1209          */
1210         if (spa->spa_sync_on) {
1211                 txg_sync_stop(spa->spa_dsl_pool);
1212                 spa->spa_sync_on = B_FALSE;
1213         }
1214 
1215         /*
1216          * Wait for any outstanding async I/O to complete.
1217          */
1218         if (spa->spa_async_zio_root != NULL) {
1219                 (void) zio_wait(spa->spa_async_zio_root);
1220                 spa->spa_async_zio_root = NULL;
1221         }
1222 
1223         bpobj_close(&spa->spa_deferred_bpobj);
1224 
1225         /*
1226          * Close the dsl pool.
1227          */
1228         if (spa->spa_dsl_pool) {
1229                 dsl_pool_close(spa->spa_dsl_pool);
1230                 spa->spa_dsl_pool = NULL;
1231                 spa->spa_meta_objset = NULL;
1232         }
1233 
1234         ddt_unload(spa);
1235 
1236         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1237 
1238         /*
1239          * Drop and purge level 2 cache
1240          */
1241         spa_l2cache_drop(spa);
1242 
1243         /*
1244          * Close all vdevs.
1245          */
1246         if (spa->spa_root_vdev)
1247                 vdev_free(spa->spa_root_vdev);
1248         ASSERT(spa->spa_root_vdev == NULL);
1249 
1250         for (i = 0; i < spa->spa_spares.sav_count; i++)
1251                 vdev_free(spa->spa_spares.sav_vdevs[i]);
1252         if (spa->spa_spares.sav_vdevs) {
1253                 kmem_free(spa->spa_spares.sav_vdevs,
1254                     spa->spa_spares.sav_count * sizeof (void *));
1255                 spa->spa_spares.sav_vdevs = NULL;
1256         }
1257         if (spa->spa_spares.sav_config) {
1258                 nvlist_free(spa->spa_spares.sav_config);
1259                 spa->spa_spares.sav_config = NULL;
1260         }
1261         spa->spa_spares.sav_count = 0;
1262 
1263         for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
1264                 vdev_clear_stats(spa->spa_l2cache.sav_vdevs[i]);
1265                 vdev_free(spa->spa_l2cache.sav_vdevs[i]);
1266         }
1267         if (spa->spa_l2cache.sav_vdevs) {
1268                 kmem_free(spa->spa_l2cache.sav_vdevs,
1269                     spa->spa_l2cache.sav_count * sizeof (void *));
1270                 spa->spa_l2cache.sav_vdevs = NULL;
1271         }
1272         if (spa->spa_l2cache.sav_config) {
1273                 nvlist_free(spa->spa_l2cache.sav_config);
1274                 spa->spa_l2cache.sav_config = NULL;
1275         }
1276         spa->spa_l2cache.sav_count = 0;
1277 
1278         spa->spa_async_suspended = 0;
1279 
1280         if (spa->spa_comment != NULL) {
1281                 spa_strfree(spa->spa_comment);
1282                 spa->spa_comment = NULL;
1283         }
1284 
1285         spa_config_exit(spa, SCL_ALL, FTAG);
1286 }
1287 
1288 /*
1289  * Load (or re-load) the current list of vdevs describing the active spares for
1290  * this pool.  When this is called, we have some form of basic information in
1291  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
1292  * then re-generate a more complete list including status information.
1293  */
1294 static void
1295 spa_load_spares(spa_t *spa)
1296 {
1297         nvlist_t **spares;
1298         uint_t nspares;
1299         int i;
1300         vdev_t *vd, *tvd;
1301 
1302         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1303 
1304         /*
1305          * First, close and free any existing spare vdevs.
1306          */
1307         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1308                 vd = spa->spa_spares.sav_vdevs[i];
1309 
1310                 /* Undo the call to spa_activate() below */
1311                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1312                     B_FALSE)) != NULL && tvd->vdev_isspare)
1313                         spa_spare_remove(tvd);
1314                 vdev_close(vd);
1315                 vdev_free(vd);
1316         }
1317 
1318         if (spa->spa_spares.sav_vdevs)
1319                 kmem_free(spa->spa_spares.sav_vdevs,
1320                     spa->spa_spares.sav_count * sizeof (void *));
1321 
1322         if (spa->spa_spares.sav_config == NULL)
1323                 nspares = 0;
1324         else
1325                 VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1326                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1327 
1328         spa->spa_spares.sav_count = (int)nspares;
1329         spa->spa_spares.sav_vdevs = NULL;
1330 
1331         if (nspares == 0)
1332                 return;
1333 
1334         /*
1335          * Construct the array of vdevs, opening them to get status in the
1336          * process.   For each spare, there is potentially two different vdev_t
1337          * structures associated with it: one in the list of spares (used only
1338          * for basic validation purposes) and one in the active vdev
1339          * configuration (if it's spared in).  During this phase we open and
1340          * validate each vdev on the spare list.  If the vdev also exists in the
1341          * active configuration, then we also mark this vdev as an active spare.
1342          */
1343         spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
1344             KM_SLEEP);
1345         for (i = 0; i < spa->spa_spares.sav_count; i++) {
1346                 VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
1347                     VDEV_ALLOC_SPARE) == 0);
1348                 ASSERT(vd != NULL);
1349 
1350                 spa->spa_spares.sav_vdevs[i] = vd;
1351 
1352                 if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1353                     B_FALSE)) != NULL) {
1354                         if (!tvd->vdev_isspare)
1355                                 spa_spare_add(tvd);
1356 
1357                         /*
1358                          * We only mark the spare active if we were successfully
1359                          * able to load the vdev.  Otherwise, importing a pool
1360                          * with a bad active spare would result in strange
1361                          * behavior, because multiple pool would think the spare
1362                          * is actively in use.
1363                          *
1364                          * There is a vulnerability here to an equally bizarre
1365                          * circumstance, where a dead active spare is later
1366                          * brought back to life (onlined or otherwise).  Given
1367                          * the rarity of this scenario, and the extra complexity
1368                          * it adds, we ignore the possibility.
1369                          */
1370                         if (!vdev_is_dead(tvd))
1371                                 spa_spare_activate(tvd);
1372                 }
1373 
1374                 vd->vdev_top = vd;
1375                 vd->vdev_aux = &spa->spa_spares;
1376 
1377                 if (vdev_open(vd) != 0)
1378                         continue;
1379 
1380                 if (vdev_validate_aux(vd) == 0)
1381                         spa_spare_add(vd);
1382         }
1383 
1384         /*
1385          * Recompute the stashed list of spares, with status information
1386          * this time.
1387          */
1388         VERIFY(nvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES,
1389             DATA_TYPE_NVLIST_ARRAY) == 0);
1390 
1391         spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
1392             KM_SLEEP);
1393         for (i = 0; i < spa->spa_spares.sav_count; i++)
1394                 spares[i] = vdev_config_generate(spa,
1395                     spa->spa_spares.sav_vdevs[i], B_TRUE, VDEV_CONFIG_SPARE);
1396         VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
1397             ZPOOL_CONFIG_SPARES, spares, spa->spa_spares.sav_count) == 0);
1398         for (i = 0; i < spa->spa_spares.sav_count; i++)
1399                 nvlist_free(spares[i]);
1400         kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
1401 }
1402 
1403 /*
1404  * Load (or re-load) the current list of vdevs describing the active l2cache for
1405  * this pool.  When this is called, we have some form of basic information in
1406  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
1407  * then re-generate a more complete list including status information.
1408  * Devices which are already active have their details maintained, and are
1409  * not re-opened.
1410  */
1411 static void
1412 spa_load_l2cache(spa_t *spa)
1413 {
1414         nvlist_t **l2cache;
1415         uint_t nl2cache;
1416         int i, j, oldnvdevs;
1417         uint64_t guid;
1418         vdev_t *vd, **oldvdevs, **newvdevs;
1419         spa_aux_vdev_t *sav = &spa->spa_l2cache;
1420 
1421         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1422 
1423         if (sav->sav_config != NULL) {
1424                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
1425                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1426                 newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
1427         } else {
1428                 nl2cache = 0;
1429                 newvdevs = NULL;
1430         }
1431 
1432         oldvdevs = sav->sav_vdevs;
1433         oldnvdevs = sav->sav_count;
1434         sav->sav_vdevs = NULL;
1435         sav->sav_count = 0;
1436 
1437         /*
1438          * Process new nvlist of vdevs.
1439          */
1440         for (i = 0; i < nl2cache; i++) {
1441                 VERIFY(nvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID,
1442                     &guid) == 0);
1443 
1444                 newvdevs[i] = NULL;
1445                 for (j = 0; j < oldnvdevs; j++) {
1446                         vd = oldvdevs[j];
1447                         if (vd != NULL && guid == vd->vdev_guid) {
1448                                 /*
1449                                  * Retain previous vdev for add/remove ops.
1450                                  */
1451                                 newvdevs[i] = vd;
1452                                 oldvdevs[j] = NULL;
1453                                 break;
1454                         }
1455                 }
1456 
1457                 if (newvdevs[i] == NULL) {
1458                         /*
1459                          * Create new vdev
1460                          */
1461                         VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
1462                             VDEV_ALLOC_L2CACHE) == 0);
1463                         ASSERT(vd != NULL);
1464                         newvdevs[i] = vd;
1465 
1466                         /*
1467                          * Commit this vdev as an l2cache device,
1468                          * even if it fails to open.
1469                          */
1470                         spa_l2cache_add(vd);
1471 
1472                         vd->vdev_top = vd;
1473                         vd->vdev_aux = sav;
1474 
1475                         spa_l2cache_activate(vd);
1476 
1477                         if (vdev_open(vd) != 0)
1478                                 continue;
1479 
1480                         (void) vdev_validate_aux(vd);
1481 
1482                         if (!vdev_is_dead(vd)) {
1483                                 boolean_t persist = B_FALSE;
1484 
1485                                 if (spa->spa_load_state != SPA_LOAD_TRYIMPORT) {
1486                                         /*
1487                                          * Only allow to do the L2ARC rebuild
1488                                          * when not doing a spa try-load.
1489                                          */
1490                                         (void) nvlist_lookup_boolean_value(
1491                                             l2cache[i],
1492                                             ZPOOL_CONFIG_L2CACHE_PERSISTENT,
1493                                             &persist);
1494                                 }
1495                                 l2arc_add_vdev(spa, vd, persist);
1496                         }
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 
1822         if (error) {
1823                 if ((BP_GET_LEVEL(bp) != 0 || DMU_OT_IS_METADATA(type)) &&
1824                     type != DMU_OT_INTENT_LOG)
1825                         atomic_add_64(&sle->sle_meta_count, 1);
1826                 else
1827                         atomic_add_64(&sle->sle_data_count, 1);
1828         }
1829         zio_data_buf_free(zio->io_data, zio->io_size);
1830 }
1831 
1832 /*ARGSUSED*/
1833 static int
1834 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1835     const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1836 {
1837         if (bp != NULL) {
1838                 zio_t *rio = arg;
1839                 size_t size = BP_GET_PSIZE(bp);
1840                 void *data = zio_data_buf_alloc(size);
1841 
1842                 zio_nowait(zio_read(rio, spa, bp, data, size,
1843                     spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
1844                     ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
1845                     ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
1846         }
1847         return (0);
1848 }
1849 
1850 static int
1851 spa_load_verify(spa_t *spa)
1852 {
1853         zio_t *rio;
1854         spa_load_error_t sle = { 0 };
1855         zpool_rewind_policy_t policy;
1856         boolean_t verify_ok = B_FALSE;
1857         int error;
1858 
1859         zpool_get_rewind_policy(spa->spa_config, &policy);
1860 
1861         if (policy.zrp_request & ZPOOL_NEVER_REWIND)
1862                 return (0);
1863 
1864         rio = zio_root(spa, NULL, &sle,
1865             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1866 
1867         error = traverse_pool(spa, spa->spa_verify_min_txg,
1868             TRAVERSE_PRE | TRAVERSE_PREFETCH, spa_load_verify_cb, rio);
1869 
1870         (void) zio_wait(rio);
1871 
1872         spa->spa_load_meta_errors = sle.sle_meta_count;
1873         spa->spa_load_data_errors = sle.sle_data_count;
1874 
1875         if (!error && sle.sle_meta_count <= policy.zrp_maxmeta &&
1876             sle.sle_data_count <= policy.zrp_maxdata) {
1877                 int64_t loss = 0;
1878 
1879                 verify_ok = B_TRUE;
1880                 spa->spa_load_txg = spa->spa_uberblock.ub_txg;
1881                 spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
1882 
1883                 loss = spa->spa_last_ubsync_txg_ts - spa->spa_load_txg_ts;
1884                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1885                     ZPOOL_CONFIG_LOAD_TIME, spa->spa_load_txg_ts) == 0);
1886                 VERIFY(nvlist_add_int64(spa->spa_load_info,
1887                     ZPOOL_CONFIG_REWIND_TIME, loss) == 0);
1888                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1889                     ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count) == 0);
1890         } else {
1891                 spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
1892         }
1893 
1894         if (error) {
1895                 if (error != ENXIO && error != EIO)
1896                         error = SET_ERROR(EIO);
1897                 return (error);
1898         }
1899 
1900         return (verify_ok ? 0 : EIO);
1901 }
1902 
1903 /*
1904  * Find a value in the pool props object.
1905  */
1906 static void
1907 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
1908 {
1909         (void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
1910             zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
1911 }
1912 
1913 /*
1914  * Find a value in the pool directory object.
1915  */
1916 static int
1917 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val)
1918 {
1919         return (zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1920             name, sizeof (uint64_t), 1, val));
1921 }
1922 
1923 static int
1924 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
1925 {
1926         vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
1927         return (err);
1928 }
1929 
1930 /*
1931  * Fix up config after a partly-completed split.  This is done with the
1932  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
1933  * pool have that entry in their config, but only the splitting one contains
1934  * a list of all the guids of the vdevs that are being split off.
1935  *
1936  * This function determines what to do with that list: either rejoin
1937  * all the disks to the pool, or complete the splitting process.  To attempt
1938  * the rejoin, each disk that is offlined is marked online again, and
1939  * we do a reopen() call.  If the vdev label for every disk that was
1940  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
1941  * then we call vdev_split() on each disk, and complete the split.
1942  *
1943  * Otherwise we leave the config alone, with all the vdevs in place in
1944  * the original pool.
1945  */
1946 static void
1947 spa_try_repair(spa_t *spa, nvlist_t *config)
1948 {
1949         uint_t extracted;
1950         uint64_t *glist;
1951         uint_t i, gcount;
1952         nvlist_t *nvl;
1953         vdev_t **vd;
1954         boolean_t attempt_reopen;
1955 
1956         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
1957                 return;
1958 
1959         /* check that the config is complete */
1960         if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
1961             &glist, &gcount) != 0)
1962                 return;
1963 
1964         vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
1965 
1966         /* attempt to online all the vdevs & validate */
1967         attempt_reopen = B_TRUE;
1968         for (i = 0; i < gcount; i++) {
1969                 if (glist[i] == 0)      /* vdev is hole */
1970                         continue;
1971 
1972                 vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
1973                 if (vd[i] == NULL) {
1974                         /*
1975                          * Don't bother attempting to reopen the disks;
1976                          * just do the split.
1977                          */
1978                         attempt_reopen = B_FALSE;
1979                 } else {
1980                         /* attempt to re-online it */
1981                         vd[i]->vdev_offline = B_FALSE;
1982                 }
1983         }
1984 
1985         if (attempt_reopen) {
1986                 vdev_reopen(spa->spa_root_vdev);
1987 
1988                 /* check each device to see what state it's in */
1989                 for (extracted = 0, i = 0; i < gcount; i++) {
1990                         if (vd[i] != NULL &&
1991                             vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
1992                                 break;
1993                         ++extracted;
1994                 }
1995         }
1996 
1997         /*
1998          * If every disk has been moved to the new pool, or if we never
1999          * even attempted to look at them, then we split them off for
2000          * good.
2001          */
2002         if (!attempt_reopen || gcount == extracted) {
2003                 for (i = 0; i < gcount; i++)
2004                         if (vd[i] != NULL)
2005                                 vdev_split(vd[i]);
2006                 vdev_reopen(spa->spa_root_vdev);
2007         }
2008 
2009         kmem_free(vd, gcount * sizeof (vdev_t *));
2010 }
2011 
2012 static int
2013 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
2014     boolean_t mosconfig)
2015 {
2016         nvlist_t *config = spa->spa_config;
2017         char *ereport = FM_EREPORT_ZFS_POOL;
2018         char *comment;
2019         int error;
2020         uint64_t pool_guid;
2021         nvlist_t *nvl;
2022 
2023         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
2024                 return (SET_ERROR(EINVAL));
2025 
2026         ASSERT(spa->spa_comment == NULL);
2027         if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
2028                 spa->spa_comment = spa_strdup(comment);
2029 
2030         /*
2031          * Versioning wasn't explicitly added to the label until later, so if
2032          * it's not present treat it as the initial version.
2033          */
2034         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
2035             &spa->spa_ubsync.ub_version) != 0)
2036                 spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
2037 
2038         (void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
2039             &spa->spa_config_txg);
2040 
2041         if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
2042             spa_guid_exists(pool_guid, 0)) {
2043                 error = SET_ERROR(EEXIST);
2044         } else {
2045                 spa->spa_config_guid = pool_guid;
2046 
2047                 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT,
2048                     &nvl) == 0) {
2049                         VERIFY(nvlist_dup(nvl, &spa->spa_config_splitting,
2050                             KM_SLEEP) == 0);
2051                 }
2052 
2053                 nvlist_free(spa->spa_load_info);
2054                 spa->spa_load_info = fnvlist_alloc();
2055 
2056                 gethrestime(&spa->spa_loaded_ts);
2057                 error = spa_load_impl(spa, pool_guid, config, state, type,
2058                     mosconfig, &ereport);
2059         }
2060 
2061         spa->spa_minref = refcount_count(&spa->spa_refcount);
2062         if (error) {
2063                 if (error != EEXIST) {
2064                         spa->spa_loaded_ts.tv_sec = 0;
2065                         spa->spa_loaded_ts.tv_nsec = 0;
2066                 }
2067                 if (error != EBADF) {
2068                         zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
2069                 }
2070         }
2071         spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
2072         spa->spa_ena = 0;
2073 
2074         return (error);
2075 }
2076 
2077 /*
2078  * Load an existing storage pool, using the pool's builtin spa_config as a
2079  * source of configuration information.
2080  */
2081 static int
2082 spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config,
2083     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
2084     char **ereport)
2085 {
2086         int error = 0;
2087         nvlist_t *nvroot = NULL;
2088         nvlist_t *label;
2089         vdev_t *rvd;
2090         uberblock_t *ub = &spa->spa_uberblock;
2091         uint64_t children, config_cache_txg = spa->spa_config_txg;
2092         int orig_mode = spa->spa_mode;
2093         int parse;
2094         uint64_t obj;
2095         boolean_t missing_feat_write = B_FALSE;
2096 
2097         /*
2098          * If this is an untrusted config, access the pool in read-only mode.
2099          * This prevents things like resilvering recently removed devices.
2100          */
2101         if (!mosconfig)
2102                 spa->spa_mode = FREAD;
2103 
2104         ASSERT(MUTEX_HELD(&spa_namespace_lock));
2105 
2106         spa->spa_load_state = state;
2107 
2108         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot))
2109                 return (SET_ERROR(EINVAL));
2110 
2111         parse = (type == SPA_IMPORT_EXISTING ?
2112             VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
2113 
2114         /*
2115          * Create "The Godfather" zio to hold all async IOs
2116          */
2117         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
2118             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
2119 
2120         /*
2121          * Parse the configuration into a vdev tree.  We explicitly set the
2122          * value that will be returned by spa_version() since parsing the
2123          * configuration requires knowing the version number.
2124          */
2125         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2126         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, parse);
2127         spa_config_exit(spa, SCL_ALL, FTAG);
2128 
2129         if (error != 0)
2130                 return (error);
2131 
2132         ASSERT(spa->spa_root_vdev == rvd);
2133 
2134         if (type != SPA_IMPORT_ASSEMBLE) {
2135                 ASSERT(spa_guid(spa) == pool_guid);
2136         }
2137 
2138         /*
2139          * Try to open all vdevs, loading each label in the process.
2140          */
2141         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2142         error = vdev_open(rvd);
2143         spa_config_exit(spa, SCL_ALL, FTAG);
2144         if (error != 0)
2145                 return (error);
2146 
2147         /*
2148          * We need to validate the vdev labels against the configuration that
2149          * we have in hand, which is dependent on the setting of mosconfig. If
2150          * mosconfig is true then we're validating the vdev labels based on
2151          * that config.  Otherwise, we're validating against the cached config
2152          * (zpool.cache) that was read when we loaded the zfs module, and then
2153          * later we will recursively call spa_load() and validate against
2154          * the vdev config.
2155          *
2156          * If we're assembling a new pool that's been split off from an
2157          * existing pool, the labels haven't yet been updated so we skip
2158          * validation for now.
2159          */
2160         if (type != SPA_IMPORT_ASSEMBLE) {
2161                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2162                 error = vdev_validate(rvd, mosconfig);
2163                 spa_config_exit(spa, SCL_ALL, FTAG);
2164 
2165                 if (error != 0)
2166                         return (error);
2167 
2168                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2169                         return (SET_ERROR(ENXIO));
2170         }
2171 
2172         /*
2173          * Find the best uberblock.
2174          */
2175         vdev_uberblock_load(rvd, ub, &label);
2176 
2177         /*
2178          * If we weren't able to find a single valid uberblock, return failure.
2179          */
2180         if (ub->ub_txg == 0) {
2181                 nvlist_free(label);
2182                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
2183         }
2184 
2185         /*
2186          * If the pool has an unsupported version we can't open it.
2187          */
2188         if (!SPA_VERSION_IS_SUPPORTED(ub->ub_version)) {
2189                 nvlist_free(label);
2190                 return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
2191         }
2192 
2193         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2194                 nvlist_t *features;
2195 
2196                 /*
2197                  * If we weren't able to find what's necessary for reading the
2198                  * MOS in the label, return failure.
2199                  */
2200                 if (label == NULL || nvlist_lookup_nvlist(label,
2201                     ZPOOL_CONFIG_FEATURES_FOR_READ, &features) != 0) {
2202                         nvlist_free(label);
2203                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2204                             ENXIO));
2205                 }
2206 
2207                 /*
2208                  * Update our in-core representation with the definitive values
2209                  * from the label.
2210                  */
2211                 nvlist_free(spa->spa_label_features);
2212                 VERIFY(nvlist_dup(features, &spa->spa_label_features, 0) == 0);
2213         }
2214 
2215         nvlist_free(label);
2216 
2217         /*
2218          * Look through entries in the label nvlist's features_for_read. If
2219          * there is a feature listed there which we don't understand then we
2220          * cannot open a pool.
2221          */
2222         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2223                 nvlist_t *unsup_feat;
2224 
2225                 VERIFY(nvlist_alloc(&unsup_feat, NV_UNIQUE_NAME, KM_SLEEP) ==
2226                     0);
2227 
2228                 for (nvpair_t *nvp = nvlist_next_nvpair(spa->spa_label_features,
2229                     NULL); nvp != NULL;
2230                     nvp = nvlist_next_nvpair(spa->spa_label_features, nvp)) {
2231                         if (!zfeature_is_supported(nvpair_name(nvp))) {
2232                                 VERIFY(nvlist_add_string(unsup_feat,
2233                                     nvpair_name(nvp), "") == 0);
2234                         }
2235                 }
2236 
2237                 if (!nvlist_empty(unsup_feat)) {
2238                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
2239                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat) == 0);
2240                         nvlist_free(unsup_feat);
2241                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2242                             ENOTSUP));
2243                 }
2244 
2245                 nvlist_free(unsup_feat);
2246         }
2247 
2248         /*
2249          * If the vdev guid sum doesn't match the uberblock, we have an
2250          * incomplete configuration.  We first check to see if the pool
2251          * is aware of the complete config (i.e ZPOOL_CONFIG_VDEV_CHILDREN).
2252          * If it is, defer the vdev_guid_sum check till later so we
2253          * can handle missing vdevs.
2254          */
2255         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN,
2256             &children) != 0 && mosconfig && type != SPA_IMPORT_ASSEMBLE &&
2257             rvd->vdev_guid_sum != ub->ub_guid_sum)
2258                 return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
2259 
2260         if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
2261                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2262                 spa_try_repair(spa, config);
2263                 spa_config_exit(spa, SCL_ALL, FTAG);
2264                 nvlist_free(spa->spa_config_splitting);
2265                 spa->spa_config_splitting = NULL;
2266         }
2267 
2268         /*
2269          * Initialize internal SPA structures.
2270          */
2271         spa->spa_state = POOL_STATE_ACTIVE;
2272         spa->spa_ubsync = spa->spa_uberblock;
2273         spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
2274             TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
2275         spa->spa_first_txg = spa->spa_last_ubsync_txg ?
2276             spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
2277         spa->spa_claim_max_txg = spa->spa_first_txg;
2278         spa->spa_prev_software_version = ub->ub_software_version;
2279 
2280         error = dsl_pool_init(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
2281         if (error)
2282                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2283         spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
2284 
2285         if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object) != 0)
2286                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2287 
2288         if (spa_version(spa) >= SPA_VERSION_FEATURES) {
2289                 boolean_t missing_feat_read = B_FALSE;
2290                 nvlist_t *unsup_feat, *enabled_feat;
2291 
2292                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_READ,
2293                     &spa->spa_feat_for_read_obj) != 0) {
2294                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2295                 }
2296 
2297                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_WRITE,
2298                     &spa->spa_feat_for_write_obj) != 0) {
2299                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2300                 }
2301 
2302                 if (spa_dir_prop(spa, DMU_POOL_FEATURE_DESCRIPTIONS,
2303                     &spa->spa_feat_desc_obj) != 0) {
2304                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2305                 }
2306 
2307                 enabled_feat = fnvlist_alloc();
2308                 unsup_feat = fnvlist_alloc();
2309 
2310                 if (!feature_is_supported(spa->spa_meta_objset,
2311                     spa->spa_feat_for_read_obj, spa->spa_feat_desc_obj,
2312                     unsup_feat, enabled_feat))
2313                         missing_feat_read = B_TRUE;
2314 
2315                 if (spa_writeable(spa) || state == SPA_LOAD_TRYIMPORT) {
2316                         if (!feature_is_supported(spa->spa_meta_objset,
2317                             spa->spa_feat_for_write_obj, spa->spa_feat_desc_obj,
2318                             unsup_feat, enabled_feat)) {
2319                                 missing_feat_write = B_TRUE;
2320                         }
2321                 }
2322 
2323                 fnvlist_add_nvlist(spa->spa_load_info,
2324                     ZPOOL_CONFIG_ENABLED_FEAT, enabled_feat);
2325 
2326                 if (!nvlist_empty(unsup_feat)) {
2327                         fnvlist_add_nvlist(spa->spa_load_info,
2328                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
2329                 }
2330 
2331                 fnvlist_free(enabled_feat);
2332                 fnvlist_free(unsup_feat);
2333 
2334                 if (!missing_feat_read) {
2335                         fnvlist_add_boolean(spa->spa_load_info,
2336                             ZPOOL_CONFIG_CAN_RDONLY);
2337                 }
2338 
2339                 /*
2340                  * If the state is SPA_LOAD_TRYIMPORT, our objective is
2341                  * twofold: to determine whether the pool is available for
2342                  * import in read-write mode and (if it is not) whether the
2343                  * pool is available for import in read-only mode. If the pool
2344                  * is available for import in read-write mode, it is displayed
2345                  * as available in userland; if it is not available for import
2346                  * in read-only mode, it is displayed as unavailable in
2347                  * userland. If the pool is available for import in read-only
2348                  * mode but not read-write mode, it is displayed as unavailable
2349                  * in userland with a special note that the pool is actually
2350                  * available for open in read-only mode.
2351                  *
2352                  * As a result, if the state is SPA_LOAD_TRYIMPORT and we are
2353                  * missing a feature for write, we must first determine whether
2354                  * the pool can be opened read-only before returning to
2355                  * userland in order to know whether to display the
2356                  * abovementioned note.
2357                  */
2358                 if (missing_feat_read || (missing_feat_write &&
2359                     spa_writeable(spa))) {
2360                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2361                             ENOTSUP));
2362                 }
2363         }
2364 
2365         spa->spa_is_initializing = B_TRUE;
2366         error = dsl_pool_open(spa->spa_dsl_pool);
2367         spa->spa_is_initializing = B_FALSE;
2368         if (error != 0)
2369                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2370 
2371         if (!mosconfig) {
2372                 uint64_t hostid;
2373                 nvlist_t *policy = NULL, *nvconfig;
2374 
2375                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2376                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2377 
2378                 if (!spa_is_root(spa) && nvlist_lookup_uint64(nvconfig,
2379                     ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
2380                         char *hostname;
2381                         unsigned long myhostid = 0;
2382 
2383                         VERIFY(nvlist_lookup_string(nvconfig,
2384                             ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
2385 
2386 #ifdef  _KERNEL
2387                         myhostid = zone_get_hostid(NULL);
2388 #else   /* _KERNEL */
2389                         /*
2390                          * We're emulating the system's hostid in userland, so
2391                          * we can't use zone_get_hostid().
2392                          */
2393                         (void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
2394 #endif  /* _KERNEL */
2395                         if (hostid != 0 && myhostid != 0 &&
2396                             hostid != myhostid) {
2397                                 nvlist_free(nvconfig);
2398                                 cmn_err(CE_WARN, "pool '%s' could not be "
2399                                     "loaded as it was last accessed by "
2400                                     "another system (host: %s hostid: 0x%lx). "
2401                                     "See: http://illumos.org/msg/ZFS-8000-EY",
2402                                     spa_name(spa), hostname,
2403                                     (unsigned long)hostid);
2404                                 return (SET_ERROR(EBADF));
2405                         }
2406                 }
2407                 if (nvlist_lookup_nvlist(spa->spa_config,
2408                     ZPOOL_REWIND_POLICY, &policy) == 0)
2409                         VERIFY(nvlist_add_nvlist(nvconfig,
2410                             ZPOOL_REWIND_POLICY, policy) == 0);
2411 
2412                 spa_config_set(spa, nvconfig);
2413                 spa_unload(spa);
2414                 spa_deactivate(spa);
2415                 spa_activate(spa, orig_mode);
2416 
2417                 return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
2418         }
2419 
2420         if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj) != 0)
2421                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2422         error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
2423         if (error != 0)
2424                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2425 
2426         /*
2427          * Load the bit that tells us to use the new accounting function
2428          * (raid-z deflation).  If we have an older pool, this will not
2429          * be present.
2430          */
2431         error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate);
2432         if (error != 0 && error != ENOENT)
2433                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2434 
2435         error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
2436             &spa->spa_creation_version);
2437         if (error != 0 && error != ENOENT)
2438                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2439 
2440         /*
2441          * Load the persistent error log.  If we have an older pool, this will
2442          * not be present.
2443          */
2444         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last);
2445         if (error != 0 && error != ENOENT)
2446                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2447 
2448         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
2449             &spa->spa_errlog_scrub);
2450         if (error != 0 && error != ENOENT)
2451                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2452 
2453         /*
2454          * Load the history object.  If we have an older pool, this
2455          * will not be present.
2456          */
2457         error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history);
2458         if (error != 0 && error != ENOENT)
2459                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2460 
2461         /*
2462          * If we're assembling the pool from the split-off vdevs of
2463          * an existing pool, we don't want to attach the spares & cache
2464          * devices.
2465          */
2466 
2467         /*
2468          * Load any hot spares for this pool.
2469          */
2470         error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object);
2471         if (error != 0 && error != ENOENT)
2472                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2473         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2474                 ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
2475                 if (load_nvlist(spa, spa->spa_spares.sav_object,
2476                     &spa->spa_spares.sav_config) != 0)
2477                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2478 
2479                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2480                 spa_load_spares(spa);
2481                 spa_config_exit(spa, SCL_ALL, FTAG);
2482         } else if (error == 0) {
2483                 spa->spa_spares.sav_sync = B_TRUE;
2484         }
2485 
2486         /*
2487          * Load any level 2 ARC devices for this pool.
2488          */
2489         error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
2490             &spa->spa_l2cache.sav_object);
2491         if (error != 0 && error != ENOENT)
2492                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2493         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2494                 ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
2495                 if (load_nvlist(spa, spa->spa_l2cache.sav_object,
2496                     &spa->spa_l2cache.sav_config) != 0)
2497                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2498 
2499                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2500                 spa_load_l2cache(spa);
2501                 spa_config_exit(spa, SCL_ALL, FTAG);
2502         } else if (error == 0) {
2503                 spa->spa_l2cache.sav_sync = B_TRUE;
2504         }
2505 
2506         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2507 
2508         error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object);
2509         if (error && error != ENOENT)
2510                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2511 
2512         if (error == 0) {
2513                 uint64_t autoreplace;
2514 
2515                 spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
2516                 spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
2517                 spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
2518                 spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
2519                 spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
2520                 spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
2521                     &spa->spa_dedup_ditto);
2522 
2523                 spa->spa_autoreplace = (autoreplace != 0);
2524         }
2525 
2526         /*
2527          * If the 'autoreplace' property is set, then post a resource notifying
2528          * the ZFS DE that it should not issue any faults for unopenable
2529          * devices.  We also iterate over the vdevs, and post a sysevent for any
2530          * unopenable vdevs so that the normal autoreplace handler can take
2531          * over.
2532          */
2533         if (spa->spa_autoreplace && state != SPA_LOAD_TRYIMPORT) {
2534                 spa_check_removed(spa->spa_root_vdev);
2535                 /*
2536                  * For the import case, this is done in spa_import(), because
2537                  * at this point we're using the spare definitions from
2538                  * the MOS config, not necessarily from the userland config.
2539                  */
2540                 if (state != SPA_LOAD_IMPORT) {
2541                         spa_aux_check_removed(&spa->spa_spares);
2542                         spa_aux_check_removed(&spa->spa_l2cache);
2543                 }
2544         }
2545 
2546         /*
2547          * Load the vdev state for all toplevel vdevs.
2548          */
2549         vdev_load(rvd);
2550 
2551         /*
2552          * Propagate the leaf DTLs we just loaded all the way up the tree.
2553          */
2554         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2555         vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
2556         spa_config_exit(spa, SCL_ALL, FTAG);
2557 
2558         /*
2559          * Load the DDTs (dedup tables).
2560          */
2561         error = ddt_load(spa);
2562         if (error != 0)
2563                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2564 
2565         spa_update_dspace(spa);
2566 
2567         /*
2568          * Validate the config, using the MOS config to fill in any
2569          * information which might be missing.  If we fail to validate
2570          * the config then declare the pool unfit for use. If we're
2571          * assembling a pool from a split, the log is not transferred
2572          * over.
2573          */
2574         if (type != SPA_IMPORT_ASSEMBLE) {
2575                 nvlist_t *nvconfig;
2576 
2577                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2578                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2579 
2580                 if (!spa_config_valid(spa, nvconfig)) {
2581                         nvlist_free(nvconfig);
2582                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
2583                             ENXIO));
2584                 }
2585                 nvlist_free(nvconfig);
2586 
2587                 /*
2588                  * Now that we've validated the config, check the state of the
2589                  * root vdev.  If it can't be opened, it indicates one or
2590                  * more toplevel vdevs are faulted.
2591                  */
2592                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2593                         return (SET_ERROR(ENXIO));
2594 
2595                 if (spa_check_logs(spa)) {
2596                         *ereport = FM_EREPORT_ZFS_LOG_REPLAY;
2597                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG, ENXIO));
2598                 }
2599         }
2600 
2601         if (missing_feat_write) {
2602                 ASSERT(state == SPA_LOAD_TRYIMPORT);
2603 
2604                 /*
2605                  * At this point, we know that we can open the pool in
2606                  * read-only mode but not read-write mode. We now have enough
2607                  * information and can return to userland.
2608                  */
2609                 return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT, ENOTSUP));
2610         }
2611 
2612         /*
2613          * We've successfully opened the pool, verify that we're ready
2614          * to start pushing transactions.
2615          */
2616         if (state != SPA_LOAD_TRYIMPORT) {
2617                 if (error = spa_load_verify(spa))
2618                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2619                             error));
2620         }
2621 
2622         if (spa_writeable(spa) && (state == SPA_LOAD_RECOVER ||
2623             spa->spa_load_max_txg == UINT64_MAX)) {
2624                 dmu_tx_t *tx;
2625                 int need_update = B_FALSE;
2626 
2627                 ASSERT(state != SPA_LOAD_TRYIMPORT);
2628 
2629                 /*
2630                  * Claim log blocks that haven't been committed yet.
2631                  * This must all happen in a single txg.
2632                  * Note: spa_claim_max_txg is updated by spa_claim_notify(),
2633                  * invoked from zil_claim_log_block()'s i/o done callback.
2634                  * Price of rollback is that we abandon the log.
2635                  */
2636                 spa->spa_claiming = B_TRUE;
2637 
2638                 tx = dmu_tx_create_assigned(spa_get_dsl(spa),
2639                     spa_first_txg(spa));
2640                 (void) dmu_objset_find(spa_name(spa),
2641                     zil_claim, tx, DS_FIND_CHILDREN);
2642                 dmu_tx_commit(tx);
2643 
2644                 spa->spa_claiming = B_FALSE;
2645 
2646                 spa_set_log_state(spa, SPA_LOG_GOOD);
2647                 spa->spa_sync_on = B_TRUE;
2648                 txg_sync_start(spa->spa_dsl_pool);
2649 
2650                 /*
2651                  * Wait for all claims to sync.  We sync up to the highest
2652                  * claimed log block birth time so that claimed log blocks
2653                  * don't appear to be from the future.  spa_claim_max_txg
2654                  * will have been set for us by either zil_check_log_chain()
2655                  * (invoked from spa_check_logs()) or zil_claim() above.
2656                  */
2657                 txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
2658 
2659                 /*
2660                  * If the config cache is stale, or we have uninitialized
2661                  * metaslabs (see spa_vdev_add()), then update the config.
2662                  *
2663                  * If this is a verbatim import, trust the current
2664                  * in-core spa_config and update the disk labels.
2665                  */
2666                 if (config_cache_txg != spa->spa_config_txg ||
2667                     state == SPA_LOAD_IMPORT ||
2668                     state == SPA_LOAD_RECOVER ||
2669                     (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
2670                         need_update = B_TRUE;
2671 
2672                 for (int c = 0; c < rvd->vdev_children; c++)
2673                         if (rvd->vdev_child[c]->vdev_ms_array == 0)
2674                                 need_update = B_TRUE;
2675 
2676                 /*
2677                  * Update the config cache asychronously in case we're the
2678                  * root pool, in which case the config cache isn't writable yet.
2679                  */
2680                 if (need_update)
2681                         spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2682 
2683                 /*
2684                  * Check all DTLs to see if anything needs resilvering.
2685                  */
2686                 if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
2687                     vdev_resilver_needed(rvd, NULL, NULL))
2688                         spa_async_request(spa, SPA_ASYNC_RESILVER);
2689 
2690                 /*
2691                  * Log the fact that we booted up (so that we can detect if
2692                  * we rebooted in the middle of an operation).
2693                  */
2694                 spa_history_log_version(spa, "open");
2695 
2696                 /*
2697                  * Delete any inconsistent datasets.
2698                  */
2699                 (void) dmu_objset_find(spa_name(spa),
2700                     dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
2701 
2702                 /*
2703                  * Clean up any stale temporary dataset userrefs.
2704                  */
2705                 dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
2706         }
2707 
2708         return (0);
2709 }
2710 
2711 static int
2712 spa_load_retry(spa_t *spa, spa_load_state_t state, int mosconfig)
2713 {
2714         int mode = spa->spa_mode;
2715 
2716         spa_unload(spa);
2717         spa_deactivate(spa);
2718 
2719         spa->spa_load_max_txg--;
2720 
2721         spa_activate(spa, mode);
2722         spa_async_suspend(spa);
2723 
2724         return (spa_load(spa, state, SPA_IMPORT_EXISTING, mosconfig));
2725 }
2726 
2727 /*
2728  * If spa_load() fails this function will try loading prior txg's. If
2729  * 'state' is SPA_LOAD_RECOVER and one of these loads succeeds the pool
2730  * will be rewound to that txg. If 'state' is not SPA_LOAD_RECOVER this
2731  * function will not rewind the pool and will return the same error as
2732  * spa_load().
2733  */
2734 static int
2735 spa_load_best(spa_t *spa, spa_load_state_t state, int mosconfig,
2736     uint64_t max_request, int rewind_flags)
2737 {
2738         nvlist_t *loadinfo = NULL;
2739         nvlist_t *config = NULL;
2740         int load_error, rewind_error;
2741         uint64_t safe_rewind_txg;
2742         uint64_t min_txg;
2743 
2744         if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
2745                 spa->spa_load_max_txg = spa->spa_load_txg;
2746                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2747         } else {
2748                 spa->spa_load_max_txg = max_request;
2749         }
2750 
2751         load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING,
2752             mosconfig);
2753         if (load_error == 0)
2754                 return (0);
2755 
2756         if (spa->spa_root_vdev != NULL)
2757                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2758 
2759         spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
2760         spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
2761 
2762         if (rewind_flags & ZPOOL_NEVER_REWIND) {
2763                 nvlist_free(config);
2764                 return (load_error);
2765         }
2766 
2767         if (state == SPA_LOAD_RECOVER) {
2768                 /* Price of rolling back is discarding txgs, including log */
2769                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2770         } else {
2771                 /*
2772                  * If we aren't rolling back save the load info from our first
2773                  * import attempt so that we can restore it after attempting
2774                  * to rewind.
2775                  */
2776                 loadinfo = spa->spa_load_info;
2777                 spa->spa_load_info = fnvlist_alloc();
2778         }
2779 
2780         spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
2781         safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
2782         min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
2783             TXG_INITIAL : safe_rewind_txg;
2784 
2785         /*
2786          * Continue as long as we're finding errors, we're still within
2787          * the acceptable rewind range, and we're still finding uberblocks
2788          */
2789         while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
2790             spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
2791                 if (spa->spa_load_max_txg < safe_rewind_txg)
2792                         spa->spa_extreme_rewind = B_TRUE;
2793                 rewind_error = spa_load_retry(spa, state, mosconfig);
2794         }
2795 
2796         spa->spa_extreme_rewind = B_FALSE;
2797         spa->spa_load_max_txg = UINT64_MAX;
2798 
2799         if (config && (rewind_error || state != SPA_LOAD_RECOVER))
2800                 spa_config_set(spa, config);
2801 
2802         if (state == SPA_LOAD_RECOVER) {
2803                 ASSERT3P(loadinfo, ==, NULL);
2804                 return (rewind_error);
2805         } else {
2806                 /* Store the rewind info as part of the initial load info */
2807                 fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
2808                     spa->spa_load_info);
2809 
2810                 /* Restore the initial load info */
2811                 fnvlist_free(spa->spa_load_info);
2812                 spa->spa_load_info = loadinfo;
2813 
2814                 return (load_error);
2815         }
2816 }
2817 
2818 /*
2819  * Pool Open/Import
2820  *
2821  * The import case is identical to an open except that the configuration is sent
2822  * down from userland, instead of grabbed from the configuration cache.  For the
2823  * case of an open, the pool configuration will exist in the
2824  * POOL_STATE_UNINITIALIZED state.
2825  *
2826  * The stats information (gen/count/ustats) is used to gather vdev statistics at
2827  * the same time open the pool, without having to keep around the spa_t in some
2828  * ambiguous state.
2829  */
2830 static int
2831 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
2832     nvlist_t **config)
2833 {
2834         spa_t *spa;
2835         spa_load_state_t state = SPA_LOAD_OPEN;
2836         int error;
2837         int locked = B_FALSE;
2838 
2839         *spapp = NULL;
2840 
2841         /*
2842          * As disgusting as this is, we need to support recursive calls to this
2843          * function because dsl_dir_open() is called during spa_load(), and ends
2844          * up calling spa_open() again.  The real fix is to figure out how to
2845          * avoid dsl_dir_open() calling this in the first place.
2846          */
2847         if (mutex_owner(&spa_namespace_lock) != curthread) {
2848                 mutex_enter(&spa_namespace_lock);
2849                 locked = B_TRUE;
2850         }
2851 
2852         if ((spa = spa_lookup(pool)) == NULL) {
2853                 if (locked)
2854                         mutex_exit(&spa_namespace_lock);
2855                 return (SET_ERROR(ENOENT));
2856         }
2857 
2858         if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
2859                 zpool_rewind_policy_t policy;
2860 
2861                 zpool_get_rewind_policy(nvpolicy ? nvpolicy : spa->spa_config,
2862                     &policy);
2863                 if (policy.zrp_request & ZPOOL_DO_REWIND)
2864                         state = SPA_LOAD_RECOVER;
2865 
2866                 spa_activate(spa, spa_mode_global);
2867 
2868                 if (state != SPA_LOAD_RECOVER)
2869                         spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
2870 
2871                 error = spa_load_best(spa, state, B_FALSE, policy.zrp_txg,
2872                     policy.zrp_request);
2873 
2874                 if (error == EBADF) {
2875                         /*
2876                          * If vdev_validate() returns failure (indicated by
2877                          * EBADF), it indicates that one of the vdevs indicates
2878                          * that the pool has been exported or destroyed.  If
2879                          * this is the case, the config cache is out of sync and
2880                          * we should remove the pool from the namespace.
2881                          */
2882                         spa_unload(spa);
2883                         spa_deactivate(spa);
2884                         spa_config_sync(spa, B_TRUE, B_TRUE);
2885                         spa_remove(spa);
2886                         if (locked)
2887                                 mutex_exit(&spa_namespace_lock);
2888                         return (SET_ERROR(ENOENT));
2889                 }
2890 
2891                 if (error) {
2892                         /*
2893                          * We can't open the pool, but we still have useful
2894                          * information: the state of each vdev after the
2895                          * attempted vdev_open().  Return this to the user.
2896                          */
2897                         if (config != NULL && spa->spa_config) {
2898                                 VERIFY(nvlist_dup(spa->spa_config, config,
2899                                     KM_SLEEP) == 0);
2900                                 VERIFY(nvlist_add_nvlist(*config,
2901                                     ZPOOL_CONFIG_LOAD_INFO,
2902                                     spa->spa_load_info) == 0);
2903                         }
2904                         spa_unload(spa);
2905                         spa_deactivate(spa);
2906                         spa->spa_last_open_failed = error;
2907                         if (locked)
2908                                 mutex_exit(&spa_namespace_lock);
2909                         *spapp = NULL;
2910                         return (error);
2911                 }
2912         }
2913 
2914         spa_open_ref(spa, tag);
2915 
2916         if (config != NULL)
2917                 *config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2918 
2919         /*
2920          * If we've recovered the pool, pass back any information we
2921          * gathered while doing the load.
2922          */
2923         if (state == SPA_LOAD_RECOVER) {
2924                 VERIFY(nvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
2925                     spa->spa_load_info) == 0);
2926         }
2927 
2928         if (locked) {
2929                 spa->spa_last_open_failed = 0;
2930                 spa->spa_last_ubsync_txg = 0;
2931                 spa->spa_load_txg = 0;
2932                 mutex_exit(&spa_namespace_lock);
2933         }
2934 
2935         *spapp = spa;
2936 
2937         return (0);
2938 }
2939 
2940 int
2941 spa_open_rewind(const char *name, spa_t **spapp, void *tag, nvlist_t *policy,
2942     nvlist_t **config)
2943 {
2944         return (spa_open_common(name, spapp, tag, policy, config));
2945 }
2946 
2947 int
2948 spa_open(const char *name, spa_t **spapp, void *tag)
2949 {
2950         return (spa_open_common(name, spapp, tag, NULL, NULL));
2951 }
2952 
2953 /*
2954  * Lookup the given spa_t, incrementing the inject count in the process,
2955  * preventing it from being exported or destroyed.
2956  */
2957 spa_t *
2958 spa_inject_addref(char *name)
2959 {
2960         spa_t *spa;
2961 
2962         mutex_enter(&spa_namespace_lock);
2963         if ((spa = spa_lookup(name)) == NULL) {
2964                 mutex_exit(&spa_namespace_lock);
2965                 return (NULL);
2966         }
2967         spa->spa_inject_ref++;
2968         mutex_exit(&spa_namespace_lock);
2969 
2970         return (spa);
2971 }
2972 
2973 void
2974 spa_inject_delref(spa_t *spa)
2975 {
2976         mutex_enter(&spa_namespace_lock);
2977         spa->spa_inject_ref--;
2978         mutex_exit(&spa_namespace_lock);
2979 }
2980 
2981 /*
2982  * Add spares device information to the nvlist.
2983  */
2984 static void
2985 spa_add_spares(spa_t *spa, nvlist_t *config)
2986 {
2987         nvlist_t **spares;
2988         uint_t i, nspares;
2989         nvlist_t *nvroot;
2990         uint64_t guid;
2991         vdev_stat_t *vs;
2992         uint_t vsc;
2993         uint64_t pool;
2994 
2995         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
2996 
2997         if (spa->spa_spares.sav_count == 0)
2998                 return;
2999 
3000         VERIFY(nvlist_lookup_nvlist(config,
3001             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3002         VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
3003             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
3004         if (nspares != 0) {
3005                 VERIFY(nvlist_add_nvlist_array(nvroot,
3006                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3007                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
3008                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
3009 
3010                 /*
3011                  * Go through and find any spares which have since been
3012                  * repurposed as an active spare.  If this is the case, update
3013                  * their status appropriately.
3014                  */
3015                 for (i = 0; i < nspares; i++) {
3016                         VERIFY(nvlist_lookup_uint64(spares[i],
3017                             ZPOOL_CONFIG_GUID, &guid) == 0);
3018                         if (spa_spare_exists(guid, &pool, NULL) &&
3019                             pool != 0ULL) {
3020                                 VERIFY(nvlist_lookup_uint64_array(
3021                                     spares[i], ZPOOL_CONFIG_VDEV_STATS,
3022                                     (uint64_t **)&vs, &vsc) == 0);
3023                                 vs->vs_state = VDEV_STATE_CANT_OPEN;
3024                                 vs->vs_aux = VDEV_AUX_SPARED;
3025                         }
3026                 }
3027         }
3028 }
3029 
3030 /*
3031  * Add l2cache device information to the nvlist, including vdev stats.
3032  */
3033 static void
3034 spa_add_l2cache(spa_t *spa, nvlist_t *config)
3035 {
3036         nvlist_t **l2cache;
3037         uint_t i, j, nl2cache;
3038         nvlist_t *nvroot;
3039         uint64_t guid;
3040         vdev_t *vd;
3041         vdev_stat_t *vs;
3042         uint_t vsc;
3043 
3044         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3045 
3046         if (spa->spa_l2cache.sav_count == 0)
3047                 return;
3048 
3049         VERIFY(nvlist_lookup_nvlist(config,
3050             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3051         VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
3052             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3053         if (nl2cache != 0) {
3054                 VERIFY(nvlist_add_nvlist_array(nvroot,
3055                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3056                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
3057                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3058 
3059                 /*
3060                  * Update level 2 cache device stats.
3061                  */
3062 
3063                 for (i = 0; i < nl2cache; i++) {
3064                         VERIFY(nvlist_lookup_uint64(l2cache[i],
3065                             ZPOOL_CONFIG_GUID, &guid) == 0);
3066 
3067                         vd = NULL;
3068                         for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
3069                                 if (guid ==
3070                                     spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
3071                                         vd = spa->spa_l2cache.sav_vdevs[j];
3072                                         break;
3073                                 }
3074                         }
3075                         ASSERT(vd != NULL);
3076 
3077                         VERIFY(nvlist_lookup_uint64_array(l2cache[i],
3078                             ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc)
3079                             == 0);
3080                         vdev_get_stats(vd, vs);
3081                 }
3082         }
3083 }
3084 
3085 static void
3086 spa_add_feature_stats(spa_t *spa, nvlist_t *config)
3087 {
3088         nvlist_t *features;
3089         zap_cursor_t zc;
3090         zap_attribute_t za;
3091 
3092         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3093         VERIFY(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3094 
3095         if (spa->spa_feat_for_read_obj != 0) {
3096                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3097                     spa->spa_feat_for_read_obj);
3098                     zap_cursor_retrieve(&zc, &za) == 0;
3099                     zap_cursor_advance(&zc)) {
3100                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3101                             za.za_num_integers == 1);
3102                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3103                             za.za_first_integer));
3104                 }
3105                 zap_cursor_fini(&zc);
3106         }
3107 
3108         if (spa->spa_feat_for_write_obj != 0) {
3109                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3110                     spa->spa_feat_for_write_obj);
3111                     zap_cursor_retrieve(&zc, &za) == 0;
3112                     zap_cursor_advance(&zc)) {
3113                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3114                             za.za_num_integers == 1);
3115                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3116                             za.za_first_integer));
3117                 }
3118                 zap_cursor_fini(&zc);
3119         }
3120 
3121         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
3122             features) == 0);
3123         nvlist_free(features);
3124 }
3125 
3126 int
3127 spa_get_stats(const char *name, nvlist_t **config,
3128     char *altroot, size_t buflen)
3129 {
3130         int error;
3131         spa_t *spa;
3132 
3133         *config = NULL;
3134         error = spa_open_common(name, &spa, FTAG, NULL, config);
3135 
3136         if (spa != NULL) {
3137                 /*
3138                  * This still leaves a window of inconsistency where the spares
3139                  * or l2cache devices could change and the config would be
3140                  * self-inconsistent.
3141                  */
3142                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3143 
3144                 if (*config != NULL) {
3145                         uint64_t loadtimes[2];
3146 
3147                         loadtimes[0] = spa->spa_loaded_ts.tv_sec;
3148                         loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
3149                         VERIFY(nvlist_add_uint64_array(*config,
3150                             ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2) == 0);
3151 
3152                         VERIFY(nvlist_add_uint64(*config,
3153                             ZPOOL_CONFIG_ERRCOUNT,
3154                             spa_get_errlog_size(spa)) == 0);
3155 
3156                         if (spa_suspended(spa))
3157                                 VERIFY(nvlist_add_uint64(*config,
3158                                     ZPOOL_CONFIG_SUSPENDED,
3159                                     spa->spa_failmode) == 0);
3160 
3161                         spa_add_spares(spa, *config);
3162                         spa_add_l2cache(spa, *config);
3163                         spa_add_feature_stats(spa, *config);
3164                 }
3165         }
3166 
3167         /*
3168          * We want to get the alternate root even for faulted pools, so we cheat
3169          * and call spa_lookup() directly.
3170          */
3171         if (altroot) {
3172                 if (spa == NULL) {
3173                         mutex_enter(&spa_namespace_lock);
3174                         spa = spa_lookup(name);
3175                         if (spa)
3176                                 spa_altroot(spa, altroot, buflen);
3177                         else
3178                                 altroot[0] = '\0';
3179                         spa = NULL;
3180                         mutex_exit(&spa_namespace_lock);
3181                 } else {
3182                         spa_altroot(spa, altroot, buflen);
3183                 }
3184         }
3185 
3186         if (spa != NULL) {
3187                 spa_config_exit(spa, SCL_CONFIG, FTAG);
3188                 spa_close(spa, FTAG);
3189         }
3190 
3191         return (error);
3192 }
3193 
3194 /*
3195  * Validate that the auxiliary device array is well formed.  We must have an
3196  * array of nvlists, each which describes a valid leaf vdev.  If this is an
3197  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
3198  * specified, as long as they are well-formed.
3199  */
3200 static int
3201 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
3202     spa_aux_vdev_t *sav, const char *config, uint64_t version,
3203     vdev_labeltype_t label)
3204 {
3205         nvlist_t **dev;
3206         uint_t i, ndev;
3207         vdev_t *vd;
3208         int error;
3209 
3210         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3211 
3212         /*
3213          * It's acceptable to have no devs specified.
3214          */
3215         if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
3216                 return (0);
3217 
3218         if (ndev == 0)
3219                 return (SET_ERROR(EINVAL));
3220 
3221         /*
3222          * Make sure the pool is formatted with a version that supports this
3223          * device type.
3224          */
3225         if (spa_version(spa) < version)
3226                 return (SET_ERROR(ENOTSUP));
3227 
3228         /*
3229          * Set the pending device list so we correctly handle device in-use
3230          * checking.
3231          */
3232         sav->sav_pending = dev;
3233         sav->sav_npending = ndev;
3234 
3235         for (i = 0; i < ndev; i++) {
3236                 if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
3237                     mode)) != 0)
3238                         goto out;
3239 
3240                 if (!vd->vdev_ops->vdev_op_leaf) {
3241                         vdev_free(vd);
3242                         error = SET_ERROR(EINVAL);
3243                         goto out;
3244                 }
3245 
3246                 /*
3247                  * The L2ARC currently only supports disk devices in
3248                  * kernel context.  For user-level testing, we allow it.
3249                  */
3250 #ifdef _KERNEL
3251                 if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
3252                     strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
3253                         error = SET_ERROR(ENOTBLK);
3254                         vdev_free(vd);
3255                         goto out;
3256                 }
3257 #endif
3258                 vd->vdev_top = vd;
3259 
3260                 if ((error = vdev_open(vd)) == 0 &&
3261                     (error = vdev_label_init(vd, crtxg, label)) == 0) {
3262                         VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
3263                             vd->vdev_guid) == 0);
3264                 }
3265 
3266                 vdev_free(vd);
3267 
3268                 if (error &&
3269                     (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
3270                         goto out;
3271                 else
3272                         error = 0;
3273         }
3274 
3275 out:
3276         sav->sav_pending = NULL;
3277         sav->sav_npending = 0;
3278         return (error);
3279 }
3280 
3281 static int
3282 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
3283 {
3284         int error;
3285 
3286         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3287 
3288         if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3289             &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
3290             VDEV_LABEL_SPARE)) != 0) {
3291                 return (error);
3292         }
3293 
3294         return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3295             &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
3296             VDEV_LABEL_L2CACHE));
3297 }
3298 
3299 static void
3300 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
3301     const char *config)
3302 {
3303         int i;
3304 
3305         if (sav->sav_config != NULL) {
3306                 nvlist_t **olddevs;
3307                 uint_t oldndevs;
3308                 nvlist_t **newdevs;
3309 
3310                 /*
3311                  * Generate new dev list by concatentating with the
3312                  * current dev list.
3313                  */
3314                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
3315                     &olddevs, &oldndevs) == 0);
3316 
3317                 newdevs = kmem_alloc(sizeof (void *) *
3318                     (ndevs + oldndevs), KM_SLEEP);
3319                 for (i = 0; i < oldndevs; i++)
3320                         VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
3321                             KM_SLEEP) == 0);
3322                 for (i = 0; i < ndevs; i++)
3323                         VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
3324                             KM_SLEEP) == 0);
3325 
3326                 VERIFY(nvlist_remove(sav->sav_config, config,
3327                     DATA_TYPE_NVLIST_ARRAY) == 0);
3328 
3329                 VERIFY(nvlist_add_nvlist_array(sav->sav_config,
3330                     config, newdevs, ndevs + oldndevs) == 0);
3331                 for (i = 0; i < oldndevs + ndevs; i++)
3332                         nvlist_free(newdevs[i]);
3333                 kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
3334         } else {
3335                 /*
3336                  * Generate a new dev list.
3337                  */
3338                 VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
3339                     KM_SLEEP) == 0);
3340                 VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
3341                     devs, ndevs) == 0);
3342         }
3343 }
3344 
3345 /*
3346  * Stop and drop level 2 ARC devices
3347  */
3348 void
3349 spa_l2cache_drop(spa_t *spa)
3350 {
3351         vdev_t *vd;
3352         int i;
3353         spa_aux_vdev_t *sav = &spa->spa_l2cache;
3354 
3355         for (i = 0; i < sav->sav_count; i++) {
3356                 uint64_t pool;
3357 
3358                 vd = sav->sav_vdevs[i];
3359                 ASSERT(vd != NULL);
3360 
3361                 if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
3362                     pool != 0ULL && l2arc_vdev_present(vd))
3363                         l2arc_remove_vdev(vd);
3364         }
3365 }
3366 
3367 /*
3368  * Pool Creation
3369  */
3370 int
3371 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
3372     nvlist_t *zplprops)
3373 {
3374         spa_t *spa;
3375         char *altroot = NULL;
3376         vdev_t *rvd;
3377         dsl_pool_t *dp;
3378         dmu_tx_t *tx;
3379         int error = 0;
3380         uint64_t txg = TXG_INITIAL;
3381         nvlist_t **spares, **l2cache;
3382         uint_t nspares, nl2cache;
3383         uint64_t version, obj;
3384         boolean_t has_features;
3385 
3386         /*
3387          * If this pool already exists, return failure.
3388          */
3389         mutex_enter(&spa_namespace_lock);
3390         if (spa_lookup(pool) != NULL) {
3391                 mutex_exit(&spa_namespace_lock);
3392                 return (SET_ERROR(EEXIST));
3393         }
3394 
3395         /*
3396          * Allocate a new spa_t structure.
3397          */
3398         (void) nvlist_lookup_string(props,
3399             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3400         spa = spa_add(pool, NULL, altroot);
3401         spa_activate(spa, spa_mode_global);
3402 
3403         if (props && (error = spa_prop_validate(spa, props))) {
3404                 spa_deactivate(spa);
3405                 spa_remove(spa);
3406                 mutex_exit(&spa_namespace_lock);
3407                 return (error);
3408         }
3409 
3410         has_features = B_FALSE;
3411         for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
3412             elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
3413                 if (zpool_prop_feature(nvpair_name(elem)))
3414                         has_features = B_TRUE;
3415         }
3416 
3417         if (has_features || nvlist_lookup_uint64(props,
3418             zpool_prop_to_name(ZPOOL_PROP_VERSION), &version) != 0) {
3419                 version = SPA_VERSION;
3420         }
3421         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
3422 
3423         spa->spa_first_txg = txg;
3424         spa->spa_uberblock.ub_txg = txg - 1;
3425         spa->spa_uberblock.ub_version = version;
3426         spa->spa_ubsync = spa->spa_uberblock;
3427 
3428         /*
3429          * Create "The Godfather" zio to hold all async IOs
3430          */
3431         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
3432             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
3433 
3434         /*
3435          * Create the root vdev.
3436          */
3437         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3438 
3439         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
3440 
3441         ASSERT(error != 0 || rvd != NULL);
3442         ASSERT(error != 0 || spa->spa_root_vdev == rvd);
3443 
3444         if (error == 0 && !zfs_allocatable_devs(nvroot))
3445                 error = SET_ERROR(EINVAL);
3446 
3447         if (error == 0 &&
3448             (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
3449             (error = spa_validate_aux(spa, nvroot, txg,
3450             VDEV_ALLOC_ADD)) == 0) {
3451                 for (int c = 0; c < rvd->vdev_children; c++) {
3452                         vdev_metaslab_set_size(rvd->vdev_child[c]);
3453                         vdev_expand(rvd->vdev_child[c], txg);
3454                 }
3455         }
3456 
3457         spa_config_exit(spa, SCL_ALL, FTAG);
3458 
3459         if (error != 0) {
3460                 spa_unload(spa);
3461                 spa_deactivate(spa);
3462                 spa_remove(spa);
3463                 mutex_exit(&spa_namespace_lock);
3464                 return (error);
3465         }
3466 
3467         /*
3468          * Get the list of spares, if specified.
3469          */
3470         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3471             &spares, &nspares) == 0) {
3472                 VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
3473                     KM_SLEEP) == 0);
3474                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3475                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3476                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3477                 spa_load_spares(spa);
3478                 spa_config_exit(spa, SCL_ALL, FTAG);
3479                 spa->spa_spares.sav_sync = B_TRUE;
3480         }
3481 
3482         /*
3483          * Get the list of level 2 cache devices, if specified.
3484          */
3485         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3486             &l2cache, &nl2cache) == 0) {
3487                 VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3488                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
3489                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3490                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3491                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3492                 spa_load_l2cache(spa);
3493                 spa_config_exit(spa, SCL_ALL, FTAG);
3494                 spa->spa_l2cache.sav_sync = B_TRUE;
3495         }
3496 
3497         spa->spa_is_initializing = B_TRUE;
3498         spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
3499         spa->spa_meta_objset = dp->dp_meta_objset;
3500         spa->spa_is_initializing = B_FALSE;
3501 
3502         /*
3503          * Create DDTs (dedup tables).
3504          */
3505         ddt_create(spa);
3506 
3507         spa_update_dspace(spa);
3508 
3509         tx = dmu_tx_create_assigned(dp, txg);
3510 
3511         /*
3512          * Create the pool config object.
3513          */
3514         spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
3515             DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
3516             DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
3517 
3518         if (zap_add(spa->spa_meta_objset,
3519             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
3520             sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
3521                 cmn_err(CE_PANIC, "failed to add pool config");
3522         }
3523 
3524         if (spa_version(spa) >= SPA_VERSION_FEATURES)
3525                 spa_feature_create_zap_objects(spa, tx);
3526 
3527         if (zap_add(spa->spa_meta_objset,
3528             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
3529             sizeof (uint64_t), 1, &version, tx) != 0) {
3530                 cmn_err(CE_PANIC, "failed to add pool version");
3531         }
3532 
3533         /* Newly created pools with the right version are always deflated. */
3534         if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
3535                 spa->spa_deflate = TRUE;
3536                 if (zap_add(spa->spa_meta_objset,
3537                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
3538                     sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
3539                         cmn_err(CE_PANIC, "failed to add deflate");
3540                 }
3541         }
3542 
3543         /*
3544          * Create the deferred-free bpobj.  Turn off compression
3545          * because sync-to-convergence takes longer if the blocksize
3546          * keeps changing.
3547          */
3548         obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
3549         dmu_object_set_compress(spa->spa_meta_objset, obj,
3550             ZIO_COMPRESS_OFF, tx);
3551         if (zap_add(spa->spa_meta_objset,
3552             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
3553             sizeof (uint64_t), 1, &obj, tx) != 0) {
3554                 cmn_err(CE_PANIC, "failed to add bpobj");
3555         }
3556         VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
3557             spa->spa_meta_objset, obj));
3558 
3559         /*
3560          * Create the pool's history object.
3561          */
3562         if (version >= SPA_VERSION_ZPOOL_HISTORY)
3563                 spa_history_create_obj(spa, tx);
3564 
3565         /*
3566          * Set pool properties.
3567          */
3568         spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
3569         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
3570         spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
3571         spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
3572 
3573         if (props != NULL) {
3574                 spa_configfile_set(spa, props, B_FALSE);
3575                 spa_sync_props(props, tx);
3576         }
3577 
3578         dmu_tx_commit(tx);
3579 
3580         spa->spa_sync_on = B_TRUE;
3581         txg_sync_start(spa->spa_dsl_pool);
3582 
3583         /*
3584          * We explicitly wait for the first transaction to complete so that our
3585          * bean counters are appropriately updated.
3586          */
3587         txg_wait_synced(spa->spa_dsl_pool, txg);
3588 
3589         spa_config_sync(spa, B_FALSE, B_TRUE);
3590 
3591         spa_history_log_version(spa, "create");
3592 
3593         spa->spa_minref = refcount_count(&spa->spa_refcount);
3594 
3595         mutex_exit(&spa_namespace_lock);
3596 
3597         return (0);
3598 }
3599 
3600 #ifdef _KERNEL
3601 /*
3602  * Get the root pool information from the root disk, then import the root pool
3603  * during the system boot up time.
3604  */
3605 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
3606 
3607 static nvlist_t *
3608 spa_generate_rootconf(char *devpath, char *devid, uint64_t *guid)
3609 {
3610         nvlist_t *config;
3611         nvlist_t *nvtop, *nvroot;
3612         uint64_t pgid;
3613 
3614         if (vdev_disk_read_rootlabel(devpath, devid, &config) != 0)
3615                 return (NULL);
3616 
3617         /*
3618          * Add this top-level vdev to the child array.
3619          */
3620         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3621             &nvtop) == 0);
3622         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
3623             &pgid) == 0);
3624         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, guid) == 0);
3625 
3626         /*
3627          * Put this pool's top-level vdevs into a root vdev.
3628          */
3629         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3630         VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
3631             VDEV_TYPE_ROOT) == 0);
3632         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
3633         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
3634         VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
3635             &nvtop, 1) == 0);
3636 
3637         /*
3638          * Replace the existing vdev_tree with the new root vdev in
3639          * this pool's configuration (remove the old, add the new).
3640          */
3641         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
3642         nvlist_free(nvroot);
3643         return (config);
3644 }
3645 
3646 /*
3647  * Walk the vdev tree and see if we can find a device with "better"
3648  * configuration. A configuration is "better" if the label on that
3649  * device has a more recent txg.
3650  */
3651 static void
3652 spa_alt_rootvdev(vdev_t *vd, vdev_t **avd, uint64_t *txg)
3653 {
3654         for (int c = 0; c < vd->vdev_children; c++)
3655                 spa_alt_rootvdev(vd->vdev_child[c], avd, txg);
3656 
3657         if (vd->vdev_ops->vdev_op_leaf) {
3658                 nvlist_t *label;
3659                 uint64_t label_txg;
3660 
3661                 if (vdev_disk_read_rootlabel(vd->vdev_physpath, vd->vdev_devid,
3662                     &label) != 0)
3663                         return;
3664 
3665                 VERIFY(nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
3666                     &label_txg) == 0);
3667 
3668                 /*
3669                  * Do we have a better boot device?
3670                  */
3671                 if (label_txg > *txg) {
3672                         *txg = label_txg;
3673                         *avd = vd;
3674                 }
3675                 nvlist_free(label);
3676         }
3677 }
3678 
3679 /*
3680  * Import a root pool.
3681  *
3682  * For x86. devpath_list will consist of devid and/or physpath name of
3683  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
3684  * The GRUB "findroot" command will return the vdev we should boot.
3685  *
3686  * For Sparc, devpath_list consists the physpath name of the booting device
3687  * no matter the rootpool is a single device pool or a mirrored pool.
3688  * e.g.
3689  *      "/pci@1f,0/ide@d/disk@0,0:a"
3690  */
3691 int
3692 spa_import_rootpool(char *devpath, char *devid)
3693 {
3694         spa_t *spa;
3695         vdev_t *rvd, *bvd, *avd = NULL;
3696         nvlist_t *config, *nvtop;
3697         uint64_t guid, txg;
3698         char *pname;
3699         int error;
3700 
3701         /*
3702          * Read the label from the boot device and generate a configuration.
3703          */
3704         config = spa_generate_rootconf(devpath, devid, &guid);
3705 #if defined(_OBP) && defined(_KERNEL)
3706         if (config == NULL) {
3707                 if (strstr(devpath, "/iscsi/ssd") != NULL) {
3708                         /* iscsi boot */
3709                         get_iscsi_bootpath_phy(devpath);
3710                         config = spa_generate_rootconf(devpath, devid, &guid);
3711                 }
3712         }
3713 #endif
3714         if (config == NULL) {
3715                 cmn_err(CE_NOTE, "Cannot read the pool label from '%s'",
3716                     devpath);
3717                 return (SET_ERROR(EIO));
3718         }
3719 
3720         VERIFY(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
3721             &pname) == 0);
3722         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
3723 
3724         mutex_enter(&spa_namespace_lock);
3725         if ((spa = spa_lookup(pname)) != NULL) {
3726                 /*
3727                  * Remove the existing root pool from the namespace so that we
3728                  * can replace it with the correct config we just read in.
3729                  */
3730                 spa_remove(spa);
3731         }
3732 
3733         spa = spa_add(pname, config, NULL);
3734         spa->spa_is_root = B_TRUE;
3735         spa->spa_import_flags = ZFS_IMPORT_VERBATIM;
3736 
3737         /*
3738          * Build up a vdev tree based on the boot device's label config.
3739          */
3740         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3741             &nvtop) == 0);
3742         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3743         error = spa_config_parse(spa, &rvd, nvtop, NULL, 0,
3744             VDEV_ALLOC_ROOTPOOL);
3745         spa_config_exit(spa, SCL_ALL, FTAG);
3746         if (error) {
3747                 mutex_exit(&spa_namespace_lock);
3748                 nvlist_free(config);
3749                 cmn_err(CE_NOTE, "Can not parse the config for pool '%s'",
3750                     pname);
3751                 return (error);
3752         }
3753 
3754         /*
3755          * Get the boot vdev.
3756          */
3757         if ((bvd = vdev_lookup_by_guid(rvd, guid)) == NULL) {
3758                 cmn_err(CE_NOTE, "Can not find the boot vdev for guid %llu",
3759                     (u_longlong_t)guid);
3760                 error = SET_ERROR(ENOENT);
3761                 goto out;
3762         }
3763 
3764         /*
3765          * Determine if there is a better boot device.
3766          */
3767         avd = bvd;
3768         spa_alt_rootvdev(rvd, &avd, &txg);
3769         if (avd != bvd) {
3770                 cmn_err(CE_NOTE, "The boot device is 'degraded'. Please "
3771                     "try booting from '%s'", avd->vdev_path);
3772                 error = SET_ERROR(EINVAL);
3773                 goto out;
3774         }
3775 
3776         /*
3777          * If the boot device is part of a spare vdev then ensure that
3778          * we're booting off the active spare.
3779          */
3780         if (bvd->vdev_parent->vdev_ops == &vdev_spare_ops &&
3781             !bvd->vdev_isspare) {
3782                 cmn_err(CE_NOTE, "The boot device is currently spared. Please "
3783                     "try booting from '%s'",
3784                     bvd->vdev_parent->
3785                     vdev_child[bvd->vdev_parent->vdev_children - 1]->vdev_path);
3786                 error = SET_ERROR(EINVAL);
3787                 goto out;
3788         }
3789 
3790         error = 0;
3791 out:
3792         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3793         vdev_free(rvd);
3794         spa_config_exit(spa, SCL_ALL, FTAG);
3795         mutex_exit(&spa_namespace_lock);
3796 
3797         nvlist_free(config);
3798         return (error);
3799 }
3800 
3801 #endif
3802 
3803 /*
3804  * Import a non-root pool into the system.
3805  */
3806 int
3807 spa_import(const char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
3808 {
3809         spa_t *spa;
3810         char *altroot = NULL;
3811         spa_load_state_t state = SPA_LOAD_IMPORT;
3812         zpool_rewind_policy_t policy;
3813         uint64_t mode = spa_mode_global;
3814         uint64_t readonly = B_FALSE;
3815         int error;
3816         nvlist_t *nvroot;
3817         nvlist_t **spares, **l2cache;
3818         uint_t nspares, nl2cache;
3819 
3820         /*
3821          * If a pool with this name exists, return failure.
3822          */
3823         mutex_enter(&spa_namespace_lock);
3824         if (spa_lookup(pool) != NULL) {
3825                 mutex_exit(&spa_namespace_lock);
3826                 return (SET_ERROR(EEXIST));
3827         }
3828 
3829         /*
3830          * Create and initialize the spa structure.
3831          */
3832         (void) nvlist_lookup_string(props,
3833             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3834         (void) nvlist_lookup_uint64(props,
3835             zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
3836         if (readonly)
3837                 mode = FREAD;
3838         spa = spa_add(pool, config, altroot);
3839         spa->spa_import_flags = flags;
3840 
3841         /*
3842          * Verbatim import - Take a pool and insert it into the namespace
3843          * as if it had been loaded at boot.
3844          */
3845         if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
3846                 if (props != NULL)
3847                         spa_configfile_set(spa, props, B_FALSE);
3848 
3849                 spa_config_sync(spa, B_FALSE, B_TRUE);
3850 
3851                 mutex_exit(&spa_namespace_lock);
3852                 spa_history_log_version(spa, "import");
3853 
3854                 return (0);
3855         }
3856 
3857         spa_activate(spa, mode);
3858 
3859         /*
3860          * Don't start async tasks until we know everything is healthy.
3861          */
3862         spa_async_suspend(spa);
3863 
3864         zpool_get_rewind_policy(config, &policy);
3865         if (policy.zrp_request & ZPOOL_DO_REWIND)
3866                 state = SPA_LOAD_RECOVER;
3867 
3868         /*
3869          * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
3870          * because the user-supplied config is actually the one to trust when
3871          * doing an import.
3872          */
3873         if (state != SPA_LOAD_RECOVER)
3874                 spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
3875 
3876         error = spa_load_best(spa, state, B_TRUE, policy.zrp_txg,
3877             policy.zrp_request);
3878 
3879         /*
3880          * Propagate anything learned while loading the pool and pass it
3881          * back to caller (i.e. rewind info, missing devices, etc).
3882          */
3883         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
3884             spa->spa_load_info) == 0);
3885 
3886         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3887         /*
3888          * Toss any existing sparelist, as it doesn't have any validity
3889          * anymore, and conflicts with spa_has_spare().
3890          */
3891         if (spa->spa_spares.sav_config) {
3892                 nvlist_free(spa->spa_spares.sav_config);
3893                 spa->spa_spares.sav_config = NULL;
3894                 spa_load_spares(spa);
3895         }
3896 
3897         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3898             &nvroot) == 0);
3899         if (error == 0)
3900                 error = spa_validate_aux(spa, nvroot, -1ULL,
3901                     VDEV_ALLOC_SPARE);
3902         if (error == 0)
3903                 error = spa_validate_aux(spa, nvroot, -1ULL,
3904                     VDEV_ALLOC_L2CACHE);
3905         spa_config_exit(spa, SCL_ALL, FTAG);
3906 
3907         if (props != NULL)
3908                 spa_configfile_set(spa, props, B_FALSE);
3909 
3910         if (error != 0 || (props && spa_writeable(spa) &&
3911             (error = spa_prop_set(spa, props)))) {
3912                 spa_unload(spa);
3913                 spa_deactivate(spa);
3914                 spa_remove(spa);
3915                 mutex_exit(&spa_namespace_lock);
3916                 return (error);
3917         }
3918 
3919         spa_async_resume(spa);
3920 
3921         /*
3922          * Override any spares and level 2 cache devices as specified by
3923          * the user, as these may have correct device names/devids, etc.
3924          */
3925         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3926             &spares, &nspares) == 0) {
3927                 if (spa->spa_spares.sav_config)
3928                         VERIFY(nvlist_remove(spa->spa_spares.sav_config,
3929                             ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
3930                 else
3931                         VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
3932                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
3933                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3934                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3935                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3936                 spa_load_spares(spa);
3937                 spa_config_exit(spa, SCL_ALL, FTAG);
3938                 spa->spa_spares.sav_sync = B_TRUE;
3939         }
3940         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3941             &l2cache, &nl2cache) == 0) {
3942                 if (spa->spa_l2cache.sav_config)
3943                         VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
3944                             ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
3945                 else
3946                         VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3947                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
3948                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3949                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3950                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3951                 spa_load_l2cache(spa);
3952                 spa_config_exit(spa, SCL_ALL, FTAG);
3953                 spa->spa_l2cache.sav_sync = B_TRUE;
3954         }
3955 
3956         /*
3957          * Check for any removed devices.
3958          */
3959         if (spa->spa_autoreplace) {
3960                 spa_aux_check_removed(&spa->spa_spares);
3961                 spa_aux_check_removed(&spa->spa_l2cache);
3962         }
3963 
3964         if (spa_writeable(spa)) {
3965                 /*
3966                  * Update the config cache to include the newly-imported pool.
3967                  */
3968                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
3969         }
3970 
3971         /*
3972          * It's possible that the pool was expanded while it was exported.
3973          * We kick off an async task to handle this for us.
3974          */
3975         spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
3976 
3977         mutex_exit(&spa_namespace_lock);
3978         spa_history_log_version(spa, "import");
3979 
3980         return (0);
3981 }
3982 
3983 nvlist_t *
3984 spa_tryimport(nvlist_t *tryconfig)
3985 {
3986         nvlist_t *config = NULL;
3987         char *poolname;
3988         spa_t *spa;
3989         uint64_t state;
3990         int error;
3991 
3992         if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
3993                 return (NULL);
3994 
3995         if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
3996                 return (NULL);
3997 
3998         /*
3999          * Create and initialize the spa structure.
4000          */
4001         mutex_enter(&spa_namespace_lock);
4002         spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
4003         spa_activate(spa, FREAD);
4004 
4005         /*
4006          * Pass off the heavy lifting to spa_load().
4007          * Pass TRUE for mosconfig because the user-supplied config
4008          * is actually the one to trust when doing an import.
4009          */
4010         error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING, B_TRUE);
4011 
4012         /*
4013          * If 'tryconfig' was at least parsable, return the current config.
4014          */
4015         if (spa->spa_root_vdev != NULL) {
4016                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
4017                 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
4018                     poolname) == 0);
4019                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4020                     state) == 0);
4021                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
4022                     spa->spa_uberblock.ub_timestamp) == 0);
4023                 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
4024                     spa->spa_load_info) == 0);
4025 
4026                 /*
4027                  * If the bootfs property exists on this pool then we
4028                  * copy it out so that external consumers can tell which
4029                  * pools are bootable.
4030                  */
4031                 if ((!error || error == EEXIST) && spa->spa_bootfs) {
4032                         char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4033 
4034                         /*
4035                          * We have to play games with the name since the
4036                          * pool was opened as TRYIMPORT_NAME.
4037                          */
4038                         if (dsl_dsobj_to_dsname(spa_name(spa),
4039                             spa->spa_bootfs, tmpname) == 0) {
4040                                 char *cp;
4041                                 char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4042 
4043                                 cp = strchr(tmpname, '/');
4044                                 if (cp == NULL) {
4045                                         (void) strlcpy(dsname, tmpname,
4046                                             MAXPATHLEN);
4047                                 } else {
4048                                         (void) snprintf(dsname, MAXPATHLEN,
4049                                             "%s/%s", poolname, ++cp);
4050                                 }
4051                                 VERIFY(nvlist_add_string(config,
4052                                     ZPOOL_CONFIG_BOOTFS, dsname) == 0);
4053                                 kmem_free(dsname, MAXPATHLEN);
4054                         }
4055                         kmem_free(tmpname, MAXPATHLEN);
4056                 }
4057 
4058                 /*
4059                  * Add the list of hot spares and level 2 cache devices.
4060                  */
4061                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
4062                 spa_add_spares(spa, config);
4063                 spa_add_l2cache(spa, config);
4064                 spa_config_exit(spa, SCL_CONFIG, FTAG);
4065         }
4066 
4067         spa_unload(spa);
4068         spa_deactivate(spa);
4069         spa_remove(spa);
4070         mutex_exit(&spa_namespace_lock);
4071 
4072         return (config);
4073 }
4074 
4075 /*
4076  * Pool export/destroy
4077  *
4078  * The act of destroying or exporting a pool is very simple.  We make sure there
4079  * is no more pending I/O and any references to the pool are gone.  Then, we
4080  * update the pool state and sync all the labels to disk, removing the
4081  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
4082  * we don't sync the labels or remove the configuration cache.
4083  */
4084 static int
4085 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
4086     boolean_t force, boolean_t hardforce)
4087 {
4088         spa_t *spa;
4089 
4090         if (oldconfig)
4091                 *oldconfig = NULL;
4092 
4093         if (!(spa_mode_global & FWRITE))
4094                 return (SET_ERROR(EROFS));
4095 
4096         mutex_enter(&spa_namespace_lock);
4097         if ((spa = spa_lookup(pool)) == NULL) {
4098                 mutex_exit(&spa_namespace_lock);
4099                 return (SET_ERROR(ENOENT));
4100         }
4101 
4102         /*
4103          * Put a hold on the pool, drop the namespace lock, stop async tasks,
4104          * reacquire the namespace lock, and see if we can export.
4105          */
4106         spa_open_ref(spa, FTAG);
4107         mutex_exit(&spa_namespace_lock);
4108         spa_async_suspend(spa);
4109         mutex_enter(&spa_namespace_lock);
4110         spa_close(spa, FTAG);
4111 
4112         /*
4113          * The pool will be in core if it's openable,
4114          * in which case we can modify its state.
4115          */
4116         if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
4117                 /*
4118                  * Objsets may be open only because they're dirty, so we
4119                  * have to force it to sync before checking spa_refcnt.
4120                  */
4121                 txg_wait_synced(spa->spa_dsl_pool, 0);
4122 
4123                 /*
4124                  * A pool cannot be exported or destroyed if there are active
4125                  * references.  If we are resetting a pool, allow references by
4126                  * fault injection handlers.
4127                  */
4128                 if (!spa_refcount_zero(spa) ||
4129                     (spa->spa_inject_ref != 0 &&
4130                     new_state != POOL_STATE_UNINITIALIZED)) {
4131                         spa_async_resume(spa);
4132                         mutex_exit(&spa_namespace_lock);
4133                         return (SET_ERROR(EBUSY));
4134                 }
4135 
4136                 /*
4137                  * A pool cannot be exported if it has an active shared spare.
4138                  * This is to prevent other pools stealing the active spare
4139                  * from an exported pool. At user's own will, such pool can
4140                  * be forcedly exported.
4141                  */
4142                 if (!force && new_state == POOL_STATE_EXPORTED &&
4143                     spa_has_active_shared_spare(spa)) {
4144                         spa_async_resume(spa);
4145                         mutex_exit(&spa_namespace_lock);
4146                         return (SET_ERROR(EXDEV));
4147                 }
4148 
4149                 /*
4150                  * We want this to be reflected on every label,
4151                  * so mark them all dirty.  spa_unload() will do the
4152                  * final sync that pushes these changes out.
4153                  */
4154                 if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
4155                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4156                         spa->spa_state = new_state;
4157                         spa->spa_final_txg = spa_last_synced_txg(spa) +
4158                             TXG_DEFER_SIZE + 1;
4159                         vdev_config_dirty(spa->spa_root_vdev);
4160                         spa_config_exit(spa, SCL_ALL, FTAG);
4161                 }
4162         }
4163 
4164         spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
4165 
4166         if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
4167                 spa_unload(spa);
4168                 spa_deactivate(spa);
4169         }
4170 
4171         if (oldconfig && spa->spa_config)
4172                 VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
4173 
4174         if (new_state != POOL_STATE_UNINITIALIZED) {
4175                 if (!hardforce)
4176                         spa_config_sync(spa, B_TRUE, B_TRUE);
4177                 spa_remove(spa);
4178         }
4179         mutex_exit(&spa_namespace_lock);
4180 
4181         return (0);
4182 }
4183 
4184 /*
4185  * Destroy a storage pool.
4186  */
4187 int
4188 spa_destroy(char *pool)
4189 {
4190         return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
4191             B_FALSE, B_FALSE));
4192 }
4193 
4194 /*
4195  * Export a storage pool.
4196  */
4197 int
4198 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
4199     boolean_t hardforce)
4200 {
4201         return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
4202             force, hardforce));
4203 }
4204 
4205 /*
4206  * Similar to spa_export(), this unloads the spa_t without actually removing it
4207  * from the namespace in any way.
4208  */
4209 int
4210 spa_reset(char *pool)
4211 {
4212         return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
4213             B_FALSE, B_FALSE));
4214 }
4215 
4216 /*
4217  * ==========================================================================
4218  * Device manipulation
4219  * ==========================================================================
4220  */
4221 
4222 /*
4223  * Add a device to a storage pool.
4224  */
4225 int
4226 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
4227 {
4228         uint64_t txg, id;
4229         int error;
4230         vdev_t *rvd = spa->spa_root_vdev;
4231         vdev_t *vd, *tvd;
4232         nvlist_t **spares, **l2cache;
4233         uint_t nspares, nl2cache;
4234 
4235         ASSERT(spa_writeable(spa));
4236 
4237         txg = spa_vdev_enter(spa);
4238 
4239         if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
4240             VDEV_ALLOC_ADD)) != 0)
4241                 return (spa_vdev_exit(spa, NULL, txg, error));
4242 
4243         spa->spa_pending_vdev = vd;  /* spa_vdev_exit() will clear this */
4244 
4245         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
4246             &nspares) != 0)
4247                 nspares = 0;
4248 
4249         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
4250             &nl2cache) != 0)
4251                 nl2cache = 0;
4252 
4253         if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
4254                 return (spa_vdev_exit(spa, vd, txg, EINVAL));
4255 
4256         if (vd->vdev_children != 0 &&
4257             (error = vdev_create(vd, txg, B_FALSE)) != 0)
4258                 return (spa_vdev_exit(spa, vd, txg, error));
4259 
4260         /*
4261          * We must validate the spares and l2cache devices after checking the
4262          * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
4263          */
4264         if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
4265                 return (spa_vdev_exit(spa, vd, txg, error));
4266 
4267         /*
4268          * Transfer each new top-level vdev from vd to rvd.
4269          */
4270         for (int c = 0; c < vd->vdev_children; c++) {
4271 
4272                 /*
4273                  * Set the vdev id to the first hole, if one exists.
4274                  */
4275                 for (id = 0; id < rvd->vdev_children; id++) {
4276                         if (rvd->vdev_child[id]->vdev_ishole) {
4277                                 vdev_free(rvd->vdev_child[id]);
4278                                 break;
4279                         }
4280                 }
4281                 tvd = vd->vdev_child[c];
4282                 vdev_remove_child(vd, tvd);
4283                 tvd->vdev_id = id;
4284                 vdev_add_child(rvd, tvd);
4285                 vdev_config_dirty(tvd);
4286         }
4287 
4288         if (nspares != 0) {
4289                 spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
4290                     ZPOOL_CONFIG_SPARES);
4291                 spa_load_spares(spa);
4292                 spa->spa_spares.sav_sync = B_TRUE;
4293         }
4294 
4295         if (nl2cache != 0) {
4296                 spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
4297                     ZPOOL_CONFIG_L2CACHE);
4298                 spa_load_l2cache(spa);
4299                 spa->spa_l2cache.sav_sync = B_TRUE;
4300         }
4301 
4302         /*
4303          * We have to be careful when adding new vdevs to an existing pool.
4304          * If other threads start allocating from these vdevs before we
4305          * sync the config cache, and we lose power, then upon reboot we may
4306          * fail to open the pool because there are DVAs that the config cache
4307          * can't translate.  Therefore, we first add the vdevs without
4308          * initializing metaslabs; sync the config cache (via spa_vdev_exit());
4309          * and then let spa_config_update() initialize the new metaslabs.
4310          *
4311          * spa_load() checks for added-but-not-initialized vdevs, so that
4312          * if we lose power at any point in this sequence, the remaining
4313          * steps will be completed the next time we load the pool.
4314          */
4315         (void) spa_vdev_exit(spa, vd, txg, 0);
4316 
4317         mutex_enter(&spa_namespace_lock);
4318         spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4319         mutex_exit(&spa_namespace_lock);
4320 
4321         return (0);
4322 }
4323 
4324 /*
4325  * Attach a device to a mirror.  The arguments are the path to any device
4326  * in the mirror, and the nvroot for the new device.  If the path specifies
4327  * a device that is not mirrored, we automatically insert the mirror vdev.
4328  *
4329  * If 'replacing' is specified, the new device is intended to replace the
4330  * existing device; in this case the two devices are made into their own
4331  * mirror using the 'replacing' vdev, which is functionally identical to
4332  * the mirror vdev (it actually reuses all the same ops) but has a few
4333  * extra rules: you can't attach to it after it's been created, and upon
4334  * completion of resilvering, the first disk (the one being replaced)
4335  * is automatically detached.
4336  */
4337 int
4338 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
4339 {
4340         uint64_t txg, dtl_max_txg;
4341         vdev_t *rvd = spa->spa_root_vdev;
4342         vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
4343         vdev_ops_t *pvops;
4344         char *oldvdpath, *newvdpath;
4345         int newvd_isspare;
4346         int error;
4347 
4348         ASSERT(spa_writeable(spa));
4349 
4350         txg = spa_vdev_enter(spa);
4351 
4352         oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
4353 
4354         if (oldvd == NULL)
4355                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4356 
4357         if (!oldvd->vdev_ops->vdev_op_leaf)
4358                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4359 
4360         pvd = oldvd->vdev_parent;
4361 
4362         if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
4363             VDEV_ALLOC_ATTACH)) != 0)
4364                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4365 
4366         if (newrootvd->vdev_children != 1)
4367                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4368 
4369         newvd = newrootvd->vdev_child[0];
4370 
4371         if (!newvd->vdev_ops->vdev_op_leaf)
4372                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4373 
4374         if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
4375                 return (spa_vdev_exit(spa, newrootvd, txg, error));
4376 
4377         /*
4378          * Spares can't replace logs
4379          */
4380         if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
4381                 return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4382 
4383         if (!replacing) {
4384                 /*
4385                  * For attach, the only allowable parent is a mirror or the root
4386                  * vdev.
4387                  */
4388                 if (pvd->vdev_ops != &vdev_mirror_ops &&
4389                     pvd->vdev_ops != &vdev_root_ops)
4390                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4391 
4392                 pvops = &vdev_mirror_ops;
4393         } else {
4394                 /*
4395                  * Active hot spares can only be replaced by inactive hot
4396                  * spares.
4397                  */
4398                 if (pvd->vdev_ops == &vdev_spare_ops &&
4399                     oldvd->vdev_isspare &&
4400                     !spa_has_spare(spa, newvd->vdev_guid))
4401                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4402 
4403                 /*
4404                  * If the source is a hot spare, and the parent isn't already a
4405                  * spare, then we want to create a new hot spare.  Otherwise, we
4406                  * want to create a replacing vdev.  The user is not allowed to
4407                  * attach to a spared vdev child unless the 'isspare' state is
4408                  * the same (spare replaces spare, non-spare replaces
4409                  * non-spare).
4410                  */
4411                 if (pvd->vdev_ops == &vdev_replacing_ops &&
4412                     spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
4413                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4414                 } else if (pvd->vdev_ops == &vdev_spare_ops &&
4415                     newvd->vdev_isspare != oldvd->vdev_isspare) {
4416                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4417                 }
4418 
4419                 if (newvd->vdev_isspare)
4420                         pvops = &vdev_spare_ops;
4421                 else
4422                         pvops = &vdev_replacing_ops;
4423         }
4424 
4425         /*
4426          * Make sure the new device is big enough.
4427          */
4428         if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
4429                 return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
4430 
4431         /*
4432          * The new device cannot have a higher alignment requirement
4433          * than the top-level vdev.
4434          */
4435         if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
4436                 return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
4437 
4438         /*
4439          * If this is an in-place replacement, update oldvd's path and devid
4440          * to make it distinguishable from newvd, and unopenable from now on.
4441          */
4442         if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
4443                 spa_strfree(oldvd->vdev_path);
4444                 oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
4445                     KM_SLEEP);
4446                 (void) sprintf(oldvd->vdev_path, "%s/%s",
4447                     newvd->vdev_path, "old");
4448                 if (oldvd->vdev_devid != NULL) {
4449                         spa_strfree(oldvd->vdev_devid);
4450                         oldvd->vdev_devid = NULL;
4451                 }
4452         }
4453 
4454         /* mark the device being resilvered */
4455         newvd->vdev_resilvering = B_TRUE;
4456 
4457         /*
4458          * If the parent is not a mirror, or if we're replacing, insert the new
4459          * mirror/replacing/spare vdev above oldvd.
4460          */
4461         if (pvd->vdev_ops != pvops)
4462                 pvd = vdev_add_parent(oldvd, pvops);
4463 
4464         ASSERT(pvd->vdev_top->vdev_parent == rvd);
4465         ASSERT(pvd->vdev_ops == pvops);
4466         ASSERT(oldvd->vdev_parent == pvd);
4467 
4468         /*
4469          * Extract the new device from its root and add it to pvd.
4470          */
4471         vdev_remove_child(newrootvd, newvd);
4472         newvd->vdev_id = pvd->vdev_children;
4473         newvd->vdev_crtxg = oldvd->vdev_crtxg;
4474         vdev_add_child(pvd, newvd);
4475 
4476         tvd = newvd->vdev_top;
4477         ASSERT(pvd->vdev_top == tvd);
4478         ASSERT(tvd->vdev_parent == rvd);
4479 
4480         vdev_config_dirty(tvd);
4481 
4482         /*
4483          * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
4484          * for any dmu_sync-ed blocks.  It will propagate upward when
4485          * spa_vdev_exit() calls vdev_dtl_reassess().
4486          */
4487         dtl_max_txg = txg + TXG_CONCURRENT_STATES;
4488 
4489         vdev_dtl_dirty(newvd, DTL_MISSING, TXG_INITIAL,
4490             dtl_max_txg - TXG_INITIAL);
4491 
4492         if (newvd->vdev_isspare) {
4493                 spa_spare_activate(newvd);
4494                 spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
4495         }
4496 
4497         oldvdpath = spa_strdup(oldvd->vdev_path);
4498         newvdpath = spa_strdup(newvd->vdev_path);
4499         newvd_isspare = newvd->vdev_isspare;
4500 
4501         /*
4502          * Mark newvd's DTL dirty in this txg.
4503          */
4504         vdev_dirty(tvd, VDD_DTL, newvd, txg);
4505 
4506         /*
4507          * Restart the resilver
4508          */
4509         dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
4510 
4511         /*
4512          * Commit the config
4513          */
4514         (void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
4515 
4516         spa_history_log_internal(spa, "vdev attach", NULL,
4517             "%s vdev=%s %s vdev=%s",
4518             replacing && newvd_isspare ? "spare in" :
4519             replacing ? "replace" : "attach", newvdpath,
4520             replacing ? "for" : "to", oldvdpath);
4521 
4522         spa_strfree(oldvdpath);
4523         spa_strfree(newvdpath);
4524 
4525         if (spa->spa_bootfs)
4526                 spa_event_notify(spa, newvd, ESC_ZFS_BOOTFS_VDEV_ATTACH);
4527 
4528         return (0);
4529 }
4530 
4531 /*
4532  * Detach a device from a mirror or replacing vdev.
4533  *
4534  * If 'replace_done' is specified, only detach if the parent
4535  * is a replacing vdev.
4536  */
4537 int
4538 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
4539 {
4540         uint64_t txg;
4541         int error;
4542         vdev_t *rvd = spa->spa_root_vdev;
4543         vdev_t *vd, *pvd, *cvd, *tvd;
4544         boolean_t unspare = B_FALSE;
4545         uint64_t unspare_guid = 0;
4546         char *vdpath;
4547 
4548         ASSERT(spa_writeable(spa));
4549 
4550         txg = spa_vdev_enter(spa);
4551 
4552         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4553 
4554         if (vd == NULL)
4555                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4556 
4557         if (!vd->vdev_ops->vdev_op_leaf)
4558                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4559 
4560         pvd = vd->vdev_parent;
4561 
4562         /*
4563          * If the parent/child relationship is not as expected, don't do it.
4564          * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
4565          * vdev that's replacing B with C.  The user's intent in replacing
4566          * is to go from M(A,B) to M(A,C).  If the user decides to cancel
4567          * the replace by detaching C, the expected behavior is to end up
4568          * M(A,B).  But suppose that right after deciding to detach C,
4569          * the replacement of B completes.  We would have M(A,C), and then
4570          * ask to detach C, which would leave us with just A -- not what
4571          * the user wanted.  To prevent this, we make sure that the
4572          * parent/child relationship hasn't changed -- in this example,
4573          * that C's parent is still the replacing vdev R.
4574          */
4575         if (pvd->vdev_guid != pguid && pguid != 0)
4576                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4577 
4578         /*
4579          * Only 'replacing' or 'spare' vdevs can be replaced.
4580          */
4581         if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
4582             pvd->vdev_ops != &vdev_spare_ops)
4583                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4584 
4585         ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
4586             spa_version(spa) >= SPA_VERSION_SPARES);
4587 
4588         /*
4589          * Only mirror, replacing, and spare vdevs support detach.
4590          */
4591         if (pvd->vdev_ops != &vdev_replacing_ops &&
4592             pvd->vdev_ops != &vdev_mirror_ops &&
4593             pvd->vdev_ops != &vdev_spare_ops)
4594                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4595 
4596         /*
4597          * If this device has the only valid copy of some data,
4598          * we cannot safely detach it.
4599          */
4600         if (vdev_dtl_required(vd))
4601                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4602 
4603         ASSERT(pvd->vdev_children >= 2);
4604 
4605         /*
4606          * If we are detaching the second disk from a replacing vdev, then
4607          * check to see if we changed the original vdev's path to have "/old"
4608          * at the end in spa_vdev_attach().  If so, undo that change now.
4609          */
4610         if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
4611             vd->vdev_path != NULL) {
4612                 size_t len = strlen(vd->vdev_path);
4613 
4614                 for (int c = 0; c < pvd->vdev_children; c++) {
4615                         cvd = pvd->vdev_child[c];
4616 
4617                         if (cvd == vd || cvd->vdev_path == NULL)
4618                                 continue;
4619 
4620                         if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
4621                             strcmp(cvd->vdev_path + len, "/old") == 0) {
4622                                 spa_strfree(cvd->vdev_path);
4623                                 cvd->vdev_path = spa_strdup(vd->vdev_path);
4624                                 break;
4625                         }
4626                 }
4627         }
4628 
4629         /*
4630          * If we are detaching the original disk from a spare, then it implies
4631          * that the spare should become a real disk, and be removed from the
4632          * active spare list for the pool.
4633          */
4634         if (pvd->vdev_ops == &vdev_spare_ops &&
4635             vd->vdev_id == 0 &&
4636             pvd->vdev_child[pvd->vdev_children - 1]->vdev_isspare)
4637                 unspare = B_TRUE;
4638 
4639         /*
4640          * Erase the disk labels so the disk can be used for other things.
4641          * This must be done after all other error cases are handled,
4642          * but before we disembowel vd (so we can still do I/O to it).
4643          * But if we can't do it, don't treat the error as fatal --
4644          * it may be that the unwritability of the disk is the reason
4645          * it's being detached!
4646          */
4647         error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4648 
4649         /*
4650          * Remove vd from its parent and compact the parent's children.
4651          */
4652         vdev_remove_child(pvd, vd);
4653         vdev_compact_children(pvd);
4654 
4655         /*
4656          * Remember one of the remaining children so we can get tvd below.
4657          */
4658         cvd = pvd->vdev_child[pvd->vdev_children - 1];
4659 
4660         /*
4661          * If we need to remove the remaining child from the list of hot spares,
4662          * do it now, marking the vdev as no longer a spare in the process.
4663          * We must do this before vdev_remove_parent(), because that can
4664          * change the GUID if it creates a new toplevel GUID.  For a similar
4665          * reason, we must remove the spare now, in the same txg as the detach;
4666          * otherwise someone could attach a new sibling, change the GUID, and
4667          * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
4668          */
4669         if (unspare) {
4670                 ASSERT(cvd->vdev_isspare);
4671                 spa_spare_remove(cvd);
4672                 unspare_guid = cvd->vdev_guid;
4673                 (void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
4674                 cvd->vdev_unspare = B_TRUE;
4675         }
4676 
4677         /*
4678          * If the parent mirror/replacing vdev only has one child,
4679          * the parent is no longer needed.  Remove it from the tree.
4680          */
4681         if (pvd->vdev_children == 1) {
4682                 if (pvd->vdev_ops == &vdev_spare_ops)
4683                         cvd->vdev_unspare = B_FALSE;
4684                 vdev_remove_parent(cvd);
4685                 cvd->vdev_resilvering = B_FALSE;
4686         }
4687 
4688 
4689         /*
4690          * We don't set tvd until now because the parent we just removed
4691          * may have been the previous top-level vdev.
4692          */
4693         tvd = cvd->vdev_top;
4694         ASSERT(tvd->vdev_parent == rvd);
4695 
4696         /*
4697          * Reevaluate the parent vdev state.
4698          */
4699         vdev_propagate_state(cvd);
4700 
4701         /*
4702          * If the 'autoexpand' property is set on the pool then automatically
4703          * try to expand the size of the pool. For example if the device we
4704          * just detached was smaller than the others, it may be possible to
4705          * add metaslabs (i.e. grow the pool). We need to reopen the vdev
4706          * first so that we can obtain the updated sizes of the leaf vdevs.
4707          */
4708         if (spa->spa_autoexpand) {
4709                 vdev_reopen(tvd);
4710                 vdev_expand(tvd, txg);
4711         }
4712 
4713         vdev_config_dirty(tvd);
4714 
4715         /*
4716          * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
4717          * vd->vdev_detached is set and free vd's DTL object in syncing context.
4718          * But first make sure we're not on any *other* txg's DTL list, to
4719          * prevent vd from being accessed after it's freed.
4720          */
4721         vdpath = spa_strdup(vd->vdev_path);
4722         for (int t = 0; t < TXG_SIZE; t++)
4723                 (void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
4724         vd->vdev_detached = B_TRUE;
4725         vdev_dirty(tvd, VDD_DTL, vd, txg);
4726 
4727         spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
4728 
4729         /* hang on to the spa before we release the lock */
4730         spa_open_ref(spa, FTAG);
4731 
4732         error = spa_vdev_exit(spa, vd, txg, 0);
4733 
4734         spa_history_log_internal(spa, "detach", NULL,
4735             "vdev=%s", vdpath);
4736         spa_strfree(vdpath);
4737 
4738         /*
4739          * If this was the removal of the original device in a hot spare vdev,
4740          * then we want to go through and remove the device from the hot spare
4741          * list of every other pool.
4742          */
4743         if (unspare) {
4744                 spa_t *altspa = NULL;
4745 
4746                 mutex_enter(&spa_namespace_lock);
4747                 while ((altspa = spa_next(altspa)) != NULL) {
4748                         if (altspa->spa_state != POOL_STATE_ACTIVE ||
4749                             altspa == spa)
4750                                 continue;
4751 
4752                         spa_open_ref(altspa, FTAG);
4753                         mutex_exit(&spa_namespace_lock);
4754                         (void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
4755                         mutex_enter(&spa_namespace_lock);
4756                         spa_close(altspa, FTAG);
4757                 }
4758                 mutex_exit(&spa_namespace_lock);
4759 
4760                 /* search the rest of the vdevs for spares to remove */
4761                 spa_vdev_resilver_done(spa);
4762         }
4763 
4764         /* all done with the spa; OK to release */
4765         mutex_enter(&spa_namespace_lock);
4766         spa_close(spa, FTAG);
4767         mutex_exit(&spa_namespace_lock);
4768 
4769         return (error);
4770 }
4771 
4772 /*
4773  * Split a set of devices from their mirrors, and create a new pool from them.
4774  */
4775 int
4776 spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
4777     nvlist_t *props, boolean_t exp)
4778 {
4779         int error = 0;
4780         uint64_t txg, *glist;
4781         spa_t *newspa;
4782         uint_t c, children, lastlog;
4783         nvlist_t **child, *nvl, *tmp;
4784         dmu_tx_t *tx;
4785         char *altroot = NULL;
4786         vdev_t *rvd, **vml = NULL;                      /* vdev modify list */
4787         boolean_t activate_slog;
4788 
4789         ASSERT(spa_writeable(spa));
4790 
4791         txg = spa_vdev_enter(spa);
4792 
4793         /* clear the log and flush everything up to now */
4794         activate_slog = spa_passivate_log(spa);
4795         (void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4796         error = spa_offline_log(spa);
4797         txg = spa_vdev_config_enter(spa);
4798 
4799         if (activate_slog)
4800                 spa_activate_log(spa);
4801 
4802         if (error != 0)
4803                 return (spa_vdev_exit(spa, NULL, txg, error));
4804 
4805         /* check new spa name before going any further */
4806         if (spa_lookup(newname) != NULL)
4807                 return (spa_vdev_exit(spa, NULL, txg, EEXIST));
4808 
4809         /*
4810          * scan through all the children to ensure they're all mirrors
4811          */
4812         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
4813             nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
4814             &children) != 0)
4815                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4816 
4817         /* first, check to ensure we've got the right child count */
4818         rvd = spa->spa_root_vdev;
4819         lastlog = 0;
4820         for (c = 0; c < rvd->vdev_children; c++) {
4821                 vdev_t *vd = rvd->vdev_child[c];
4822 
4823                 /* don't count the holes & logs as children */
4824                 if (vd->vdev_islog || vd->vdev_ishole) {
4825                         if (lastlog == 0)
4826                                 lastlog = c;
4827                         continue;
4828                 }
4829 
4830                 lastlog = 0;
4831         }
4832         if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
4833                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4834 
4835         /* next, ensure no spare or cache devices are part of the split */
4836         if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
4837             nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
4838                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4839 
4840         vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
4841         glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
4842 
4843         /* then, loop over each vdev and validate it */
4844         for (c = 0; c < children; c++) {
4845                 uint64_t is_hole = 0;
4846 
4847                 (void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
4848                     &is_hole);
4849 
4850                 if (is_hole != 0) {
4851                         if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
4852                             spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
4853                                 continue;
4854                         } else {
4855                                 error = SET_ERROR(EINVAL);
4856                                 break;
4857                         }
4858                 }
4859 
4860                 /* which disk is going to be split? */
4861                 if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
4862                     &glist[c]) != 0) {
4863                         error = SET_ERROR(EINVAL);
4864                         break;
4865                 }
4866 
4867                 /* look it up in the spa */
4868                 vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
4869                 if (vml[c] == NULL) {
4870                         error = SET_ERROR(ENODEV);
4871                         break;
4872                 }
4873 
4874                 /* make sure there's nothing stopping the split */
4875                 if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
4876                     vml[c]->vdev_islog ||
4877                     vml[c]->vdev_ishole ||
4878                     vml[c]->vdev_isspare ||
4879                     vml[c]->vdev_isl2cache ||
4880                     !vdev_writeable(vml[c]) ||
4881                     vml[c]->vdev_children != 0 ||
4882                     vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
4883                     c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
4884                         error = SET_ERROR(EINVAL);
4885                         break;
4886                 }
4887 
4888                 if (vdev_dtl_required(vml[c])) {
4889                         error = SET_ERROR(EBUSY);
4890                         break;
4891                 }
4892 
4893                 /* we need certain info from the top level */
4894                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
4895                     vml[c]->vdev_top->vdev_ms_array) == 0);
4896                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
4897                     vml[c]->vdev_top->vdev_ms_shift) == 0);
4898                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
4899                     vml[c]->vdev_top->vdev_asize) == 0);
4900                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
4901                     vml[c]->vdev_top->vdev_ashift) == 0);
4902         }
4903 
4904         if (error != 0) {
4905                 kmem_free(vml, children * sizeof (vdev_t *));
4906                 kmem_free(glist, children * sizeof (uint64_t));
4907                 return (spa_vdev_exit(spa, NULL, txg, error));
4908         }
4909 
4910         /* stop writers from using the disks */
4911         for (c = 0; c < children; c++) {
4912                 if (vml[c] != NULL)
4913                         vml[c]->vdev_offline = B_TRUE;
4914         }
4915         vdev_reopen(spa->spa_root_vdev);
4916 
4917         /*
4918          * Temporarily record the splitting vdevs in the spa config.  This
4919          * will disappear once the config is regenerated.
4920          */
4921         VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0);
4922         VERIFY(nvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
4923             glist, children) == 0);
4924         kmem_free(glist, children * sizeof (uint64_t));
4925 
4926         mutex_enter(&spa->spa_props_lock);
4927         VERIFY(nvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT,
4928             nvl) == 0);
4929         mutex_exit(&spa->spa_props_lock);
4930         spa->spa_config_splitting = nvl;
4931         vdev_config_dirty(spa->spa_root_vdev);
4932 
4933         /* configure and create the new pool */
4934         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname) == 0);
4935         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4936             exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE) == 0);
4937         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
4938             spa_version(spa)) == 0);
4939         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
4940             spa->spa_config_txg) == 0);
4941         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
4942             spa_generate_guid(NULL)) == 0);
4943         (void) nvlist_lookup_string(props,
4944             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
4945 
4946         /* add the new pool to the namespace */
4947         newspa = spa_add(newname, config, altroot);
4948         newspa->spa_config_txg = spa->spa_config_txg;
4949         spa_set_log_state(newspa, SPA_LOG_CLEAR);
4950 
4951         /* release the spa config lock, retaining the namespace lock */
4952         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4953 
4954         if (zio_injection_enabled)
4955                 zio_handle_panic_injection(spa, FTAG, 1);
4956 
4957         spa_activate(newspa, spa_mode_global);
4958         spa_async_suspend(newspa);
4959 
4960         /* create the new pool from the disks of the original pool */
4961         error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE, B_TRUE);
4962         if (error)
4963                 goto out;
4964 
4965         /* if that worked, generate a real config for the new pool */
4966         if (newspa->spa_root_vdev != NULL) {
4967                 VERIFY(nvlist_alloc(&newspa->spa_config_splitting,
4968                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
4969                 VERIFY(nvlist_add_uint64(newspa->spa_config_splitting,
4970                     ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa)) == 0);
4971                 spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
4972                     B_TRUE));
4973         }
4974 
4975         /* set the props */
4976         if (props != NULL) {
4977                 spa_configfile_set(newspa, props, B_FALSE);
4978                 error = spa_prop_set(newspa, props);
4979                 if (error)
4980                         goto out;
4981         }
4982 
4983         /* flush everything */
4984         txg = spa_vdev_config_enter(newspa);
4985         vdev_config_dirty(newspa->spa_root_vdev);
4986         (void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
4987 
4988         if (zio_injection_enabled)
4989                 zio_handle_panic_injection(spa, FTAG, 2);
4990 
4991         spa_async_resume(newspa);
4992 
4993         /* finally, update the original pool's config */
4994         txg = spa_vdev_config_enter(spa);
4995         tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
4996         error = dmu_tx_assign(tx, TXG_WAIT);
4997         if (error != 0)
4998                 dmu_tx_abort(tx);
4999         for (c = 0; c < children; c++) {
5000                 if (vml[c] != NULL) {
5001                         vdev_split(vml[c]);
5002                         if (error == 0)
5003                                 spa_history_log_internal(spa, "detach", tx,
5004                                     "vdev=%s", vml[c]->vdev_path);
5005                         vdev_free(vml[c]);
5006                 }
5007         }
5008         vdev_config_dirty(spa->spa_root_vdev);
5009         spa->spa_config_splitting = NULL;
5010         nvlist_free(nvl);
5011         if (error == 0)
5012                 dmu_tx_commit(tx);
5013         (void) spa_vdev_exit(spa, NULL, txg, 0);
5014 
5015         if (zio_injection_enabled)
5016                 zio_handle_panic_injection(spa, FTAG, 3);
5017 
5018         /* split is complete; log a history record */
5019         spa_history_log_internal(newspa, "split", NULL,
5020             "from pool %s", spa_name(spa));
5021 
5022         kmem_free(vml, children * sizeof (vdev_t *));
5023 
5024         /* if we're not going to mount the filesystems in userland, export */
5025         if (exp)
5026                 error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
5027                     B_FALSE, B_FALSE);
5028 
5029         return (error);
5030 
5031 out:
5032         spa_unload(newspa);
5033         spa_deactivate(newspa);
5034         spa_remove(newspa);
5035 
5036         txg = spa_vdev_config_enter(spa);
5037 
5038         /* re-online all offlined disks */
5039         for (c = 0; c < children; c++) {
5040                 if (vml[c] != NULL)
5041                         vml[c]->vdev_offline = B_FALSE;
5042         }
5043         vdev_reopen(spa->spa_root_vdev);
5044 
5045         nvlist_free(spa->spa_config_splitting);
5046         spa->spa_config_splitting = NULL;
5047         (void) spa_vdev_exit(spa, NULL, txg, error);
5048 
5049         kmem_free(vml, children * sizeof (vdev_t *));
5050         return (error);
5051 }
5052 
5053 static nvlist_t *
5054 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
5055 {
5056         for (int i = 0; i < count; i++) {
5057                 uint64_t guid;
5058 
5059                 VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
5060                     &guid) == 0);
5061 
5062                 if (guid == target_guid)
5063                         return (nvpp[i]);
5064         }
5065 
5066         return (NULL);
5067 }
5068 
5069 static void
5070 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
5071         nvlist_t *dev_to_remove)
5072 {
5073         nvlist_t **newdev = NULL;
5074 
5075         if (count > 1)
5076                 newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
5077 
5078         for (int i = 0, j = 0; i < count; i++) {
5079                 if (dev[i] == dev_to_remove)
5080                         continue;
5081                 VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
5082         }
5083 
5084         VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
5085         VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
5086 
5087         for (int i = 0; i < count - 1; i++)
5088                 nvlist_free(newdev[i]);
5089 
5090         if (count > 1)
5091                 kmem_free(newdev, (count - 1) * sizeof (void *));
5092 }
5093 
5094 /*
5095  * Evacuate the device.
5096  */
5097 static int
5098 spa_vdev_remove_evacuate(spa_t *spa, vdev_t *vd)
5099 {
5100         uint64_t txg;
5101         int error = 0;
5102 
5103         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5104         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5105         ASSERT(vd == vd->vdev_top);
5106 
5107         /*
5108          * Evacuate the device.  We don't hold the config lock as writer
5109          * since we need to do I/O but we do keep the
5110          * spa_namespace_lock held.  Once this completes the device
5111          * should no longer have any blocks allocated on it.
5112          */
5113         if (vd->vdev_islog) {
5114                 if (vd->vdev_stat.vs_alloc != 0)
5115                         error = spa_offline_log(spa);
5116         } else {
5117                 error = SET_ERROR(ENOTSUP);
5118         }
5119 
5120         if (error)
5121                 return (error);
5122 
5123         /*
5124          * The evacuation succeeded.  Remove any remaining MOS metadata
5125          * associated with this vdev, and wait for these changes to sync.
5126          */
5127         ASSERT0(vd->vdev_stat.vs_alloc);
5128         txg = spa_vdev_config_enter(spa);
5129         vd->vdev_removing = B_TRUE;
5130         vdev_dirty(vd, 0, NULL, txg);
5131         vdev_config_dirty(vd);
5132         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
5133 
5134         return (0);
5135 }
5136 
5137 /*
5138  * Complete the removal by cleaning up the namespace.
5139  */
5140 static void
5141 spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
5142 {
5143         vdev_t *rvd = spa->spa_root_vdev;
5144         uint64_t id = vd->vdev_id;
5145         boolean_t last_vdev = (id == (rvd->vdev_children - 1));
5146 
5147         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5148         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
5149         ASSERT(vd == vd->vdev_top);
5150 
5151         /*
5152          * Only remove any devices which are empty.
5153          */
5154         if (vd->vdev_stat.vs_alloc != 0)
5155                 return;
5156 
5157         (void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
5158 
5159         if (list_link_active(&vd->vdev_state_dirty_node))
5160                 vdev_state_clean(vd);
5161         if (list_link_active(&vd->vdev_config_dirty_node))
5162                 vdev_config_clean(vd);
5163 
5164         vdev_free(vd);
5165 
5166         if (last_vdev) {
5167                 vdev_compact_children(rvd);
5168         } else {
5169                 vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops);
5170                 vdev_add_child(rvd, vd);
5171         }
5172         vdev_config_dirty(rvd);
5173 
5174         /*
5175          * Reassess the health of our root vdev.
5176          */
5177         vdev_reopen(rvd);
5178 }
5179 
5180 /*
5181  * Remove a device from the pool -
5182  *
5183  * Removing a device from the vdev namespace requires several steps
5184  * and can take a significant amount of time.  As a result we use
5185  * the spa_vdev_config_[enter/exit] functions which allow us to
5186  * grab and release the spa_config_lock while still holding the namespace
5187  * lock.  During each step the configuration is synced out.
5188  *
5189  * Currently, this supports removing only hot spares, slogs, and level 2 ARC
5190  * devices.
5191  */
5192 int
5193 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
5194 {
5195         vdev_t *vd;
5196         metaslab_group_t *mg;
5197         nvlist_t **spares, **l2cache, *nv;
5198         uint64_t txg = 0;
5199         uint_t nspares, nl2cache;
5200         int error = 0;
5201         boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
5202 
5203         ASSERT(spa_writeable(spa));
5204 
5205         if (!locked)
5206                 txg = spa_vdev_enter(spa);
5207 
5208         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
5209 
5210         if (spa->spa_spares.sav_vdevs != NULL &&
5211             nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
5212             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
5213             (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
5214                 /*
5215                  * Only remove the hot spare if it's not currently in use
5216                  * in this pool.
5217                  */
5218                 if (vd == NULL || unspare) {
5219                         spa_vdev_remove_aux(spa->spa_spares.sav_config,
5220                             ZPOOL_CONFIG_SPARES, spares, nspares, nv);
5221                         spa_load_spares(spa);
5222                         spa->spa_spares.sav_sync = B_TRUE;
5223                 } else {
5224                         error = SET_ERROR(EBUSY);
5225                 }
5226         } else if (spa->spa_l2cache.sav_vdevs != NULL &&
5227             nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
5228             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
5229             (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
5230                 /*
5231                  * Cache devices can always be removed.
5232                  */
5233                 spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
5234                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
5235                 spa_load_l2cache(spa);
5236                 spa->spa_l2cache.sav_sync = B_TRUE;
5237         } else if (vd != NULL && vd->vdev_islog) {
5238                 ASSERT(!locked);
5239                 ASSERT(vd == vd->vdev_top);
5240 
5241                 /*
5242                  * XXX - Once we have bp-rewrite this should
5243                  * become the common case.
5244                  */
5245 
5246                 mg = vd->vdev_mg;
5247 
5248                 /*
5249                  * Stop allocating from this vdev.
5250                  */
5251                 metaslab_group_passivate(mg);
5252 
5253                 /*
5254                  * Wait for the youngest allocations and frees to sync,
5255                  * and then wait for the deferral of those frees to finish.
5256                  */
5257                 spa_vdev_config_exit(spa, NULL,
5258                     txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
5259 
5260                 /*
5261                  * Attempt to evacuate the vdev.
5262                  */
5263                 error = spa_vdev_remove_evacuate(spa, vd);
5264 
5265                 txg = spa_vdev_config_enter(spa);
5266 
5267                 /*
5268                  * If we couldn't evacuate the vdev, unwind.
5269                  */
5270                 if (error) {
5271                         metaslab_group_activate(mg);
5272                         return (spa_vdev_exit(spa, NULL, txg, error));
5273                 }
5274 
5275                 /*
5276                  * Clean up the vdev namespace.
5277                  */
5278                 spa_vdev_remove_from_namespace(spa, vd);
5279 
5280         } else if (vd != NULL) {
5281                 /*
5282                  * Normal vdevs cannot be removed (yet).
5283                  */
5284                 error = SET_ERROR(ENOTSUP);
5285         } else {
5286                 /*
5287                  * There is no vdev of any kind with the specified guid.
5288                  */
5289                 error = SET_ERROR(ENOENT);
5290         }
5291 
5292         if (!locked)
5293                 return (spa_vdev_exit(spa, NULL, txg, error));
5294 
5295         return (error);
5296 }
5297 
5298 /*
5299  * Find any device that's done replacing, or a vdev marked 'unspare' that's
5300  * currently spared, so we can detach it.
5301  */
5302 static vdev_t *
5303 spa_vdev_resilver_done_hunt(vdev_t *vd)
5304 {
5305         vdev_t *newvd, *oldvd;
5306 
5307         for (int c = 0; c < vd->vdev_children; c++) {
5308                 oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
5309                 if (oldvd != NULL)
5310                         return (oldvd);
5311         }
5312 
5313         /*
5314          * Check for a completed replacement.  We always consider the first
5315          * vdev in the list to be the oldest vdev, and the last one to be
5316          * the newest (see spa_vdev_attach() for how that works).  In
5317          * the case where the newest vdev is faulted, we will not automatically
5318          * remove it after a resilver completes.  This is OK as it will require
5319          * user intervention to determine which disk the admin wishes to keep.
5320          */
5321         if (vd->vdev_ops == &vdev_replacing_ops) {
5322                 ASSERT(vd->vdev_children > 1);
5323 
5324                 newvd = vd->vdev_child[vd->vdev_children - 1];
5325                 oldvd = vd->vdev_child[0];
5326 
5327                 if (vdev_dtl_empty(newvd, DTL_MISSING) &&
5328                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5329                     !vdev_dtl_required(oldvd))
5330                         return (oldvd);
5331         }
5332 
5333         /*
5334          * Check for a completed resilver with the 'unspare' flag set.
5335          */
5336         if (vd->vdev_ops == &vdev_spare_ops) {
5337                 vdev_t *first = vd->vdev_child[0];
5338                 vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
5339 
5340                 if (last->vdev_unspare) {
5341                         oldvd = first;
5342                         newvd = last;
5343                 } else if (first->vdev_unspare) {
5344                         oldvd = last;
5345                         newvd = first;
5346                 } else {
5347                         oldvd = NULL;
5348                 }
5349 
5350                 if (oldvd != NULL &&
5351                     vdev_dtl_empty(newvd, DTL_MISSING) &&
5352                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5353                     !vdev_dtl_required(oldvd))
5354                         return (oldvd);
5355 
5356                 /*
5357                  * If there are more than two spares attached to a disk,
5358                  * and those spares are not required, then we want to
5359                  * attempt to free them up now so that they can be used
5360                  * by other pools.  Once we're back down to a single
5361                  * disk+spare, we stop removing them.
5362                  */
5363                 if (vd->vdev_children > 2) {
5364                         newvd = vd->vdev_child[1];
5365 
5366                         if (newvd->vdev_isspare && last->vdev_isspare &&
5367                             vdev_dtl_empty(last, DTL_MISSING) &&
5368                             vdev_dtl_empty(last, DTL_OUTAGE) &&
5369                             !vdev_dtl_required(newvd))
5370                                 return (newvd);
5371                 }
5372         }
5373 
5374         return (NULL);
5375 }
5376 
5377 static void
5378 spa_vdev_resilver_done(spa_t *spa)
5379 {
5380         vdev_t *vd, *pvd, *ppvd;
5381         uint64_t guid, sguid, pguid, ppguid;
5382 
5383         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5384 
5385         while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
5386                 pvd = vd->vdev_parent;
5387                 ppvd = pvd->vdev_parent;
5388                 guid = vd->vdev_guid;
5389                 pguid = pvd->vdev_guid;
5390                 ppguid = ppvd->vdev_guid;
5391                 sguid = 0;
5392                 /*
5393                  * If we have just finished replacing a hot spared device, then
5394                  * we need to detach the parent's first child (the original hot
5395                  * spare) as well.
5396                  */
5397                 if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
5398                     ppvd->vdev_children == 2) {
5399                         ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
5400                         sguid = ppvd->vdev_child[1]->vdev_guid;
5401                 }
5402                 spa_config_exit(spa, SCL_ALL, FTAG);
5403                 if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
5404                         return;
5405                 if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
5406                         return;
5407                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5408         }
5409 
5410         spa_config_exit(spa, SCL_ALL, FTAG);
5411 }
5412 
5413 /*
5414  * Update the stored path or FRU for this vdev.
5415  */
5416 int
5417 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
5418     boolean_t ispath)
5419 {
5420         vdev_t *vd;
5421         boolean_t sync = B_FALSE;
5422 
5423         ASSERT(spa_writeable(spa));
5424 
5425         spa_vdev_state_enter(spa, SCL_ALL);
5426 
5427         if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
5428                 return (spa_vdev_state_exit(spa, NULL, ENOENT));
5429 
5430         if (!vd->vdev_ops->vdev_op_leaf)
5431                 return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
5432 
5433         if (ispath) {
5434                 if (strcmp(value, vd->vdev_path) != 0) {
5435                         spa_strfree(vd->vdev_path);
5436                         vd->vdev_path = spa_strdup(value);
5437                         sync = B_TRUE;
5438                 }
5439         } else {
5440                 if (vd->vdev_fru == NULL) {
5441                         vd->vdev_fru = spa_strdup(value);
5442                         sync = B_TRUE;
5443                 } else if (strcmp(value, vd->vdev_fru) != 0) {
5444                         spa_strfree(vd->vdev_fru);
5445                         vd->vdev_fru = spa_strdup(value);
5446                         sync = B_TRUE;
5447                 }
5448         }
5449 
5450         return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
5451 }
5452 
5453 int
5454 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
5455 {
5456         return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
5457 }
5458 
5459 int
5460 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
5461 {
5462         return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
5463 }
5464 
5465 /*
5466  * ==========================================================================
5467  * SPA Scanning
5468  * ==========================================================================
5469  */
5470 
5471 int
5472 spa_scan_stop(spa_t *spa)
5473 {
5474         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5475         if (dsl_scan_resilvering(spa->spa_dsl_pool))
5476                 return (SET_ERROR(EBUSY));
5477         return (dsl_scan_cancel(spa->spa_dsl_pool));
5478 }
5479 
5480 int
5481 spa_scan(spa_t *spa, pool_scan_func_t func)
5482 {
5483         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5484 
5485         if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
5486                 return (SET_ERROR(ENOTSUP));
5487 
5488         /*
5489          * If a resilver was requested, but there is no DTL on a
5490          * writeable leaf device, we have nothing to do.
5491          */
5492         if (func == POOL_SCAN_RESILVER &&
5493             !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
5494                 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
5495                 return (0);
5496         }
5497 
5498         return (dsl_scan(spa->spa_dsl_pool, func));
5499 }
5500 
5501 /*
5502  * ==========================================================================
5503  * SPA async task processing
5504  * ==========================================================================
5505  */
5506 
5507 static void
5508 spa_async_remove(spa_t *spa, vdev_t *vd)
5509 {
5510         if (vd->vdev_remove_wanted) {
5511                 vd->vdev_remove_wanted = B_FALSE;
5512                 vd->vdev_delayed_close = B_FALSE;
5513                 vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
5514 
5515                 /*
5516                  * We want to clear the stats, but we don't want to do a full
5517                  * vdev_clear() as that will cause us to throw away
5518                  * degraded/faulted state as well as attempt to reopen the
5519                  * device, all of which is a waste.
5520                  */
5521                 vd->vdev_stat.vs_read_errors = 0;
5522                 vd->vdev_stat.vs_write_errors = 0;
5523                 vd->vdev_stat.vs_checksum_errors = 0;
5524 
5525                 vdev_state_dirty(vd->vdev_top);
5526         }
5527 
5528         for (int c = 0; c < vd->vdev_children; c++)
5529                 spa_async_remove(spa, vd->vdev_child[c]);
5530 }
5531 
5532 static void
5533 spa_async_probe(spa_t *spa, vdev_t *vd)
5534 {
5535         if (vd->vdev_probe_wanted) {
5536                 vd->vdev_probe_wanted = B_FALSE;
5537                 vdev_reopen(vd);        /* vdev_open() does the actual probe */
5538         }
5539 
5540         for (int c = 0; c < vd->vdev_children; c++)
5541                 spa_async_probe(spa, vd->vdev_child[c]);
5542 }
5543 
5544 static void
5545 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
5546 {
5547         sysevent_id_t eid;
5548         nvlist_t *attr;
5549         char *physpath;
5550 
5551         if (!spa->spa_autoexpand)
5552                 return;
5553 
5554         for (int c = 0; c < vd->vdev_children; c++) {
5555                 vdev_t *cvd = vd->vdev_child[c];
5556                 spa_async_autoexpand(spa, cvd);
5557         }
5558 
5559         if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
5560                 return;
5561 
5562         physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
5563         (void) snprintf(physpath, MAXPATHLEN, "/devices%s", vd->vdev_physpath);
5564 
5565         VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5566         VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
5567 
5568         (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
5569             ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
5570 
5571         nvlist_free(attr);
5572         kmem_free(physpath, MAXPATHLEN);
5573 }
5574 
5575 static void
5576 spa_async_thread(spa_t *spa)
5577 {
5578         int tasks;
5579 
5580         ASSERT(spa->spa_sync_on);
5581 
5582         mutex_enter(&spa->spa_async_lock);
5583         tasks = spa->spa_async_tasks;
5584         spa->spa_async_tasks = 0;
5585         mutex_exit(&spa->spa_async_lock);
5586 
5587         /*
5588          * See if the config needs to be updated.
5589          */
5590         if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
5591                 uint64_t old_space, new_space;
5592 
5593                 mutex_enter(&spa_namespace_lock);
5594                 old_space = metaslab_class_get_space(spa_normal_class(spa));
5595                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
5596                 new_space = metaslab_class_get_space(spa_normal_class(spa));
5597                 mutex_exit(&spa_namespace_lock);
5598 
5599                 /*
5600                  * If the pool grew as a result of the config update,
5601                  * then log an internal history event.
5602                  */
5603                 if (new_space != old_space) {
5604                         spa_history_log_internal(spa, "vdev online", NULL,
5605                             "pool '%s' size: %llu(+%llu)",
5606                             spa_name(spa), new_space, new_space - old_space);
5607                 }
5608         }
5609 
5610         /*
5611          * See if any devices need to be marked REMOVED.
5612          */
5613         if (tasks & SPA_ASYNC_REMOVE) {
5614                 spa_vdev_state_enter(spa, SCL_NONE);
5615                 spa_async_remove(spa, spa->spa_root_vdev);
5616                 for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
5617                         spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
5618                 for (int i = 0; i < spa->spa_spares.sav_count; i++)
5619                         spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
5620                 (void) spa_vdev_state_exit(spa, NULL, 0);
5621         }
5622 
5623         if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
5624                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5625                 spa_async_autoexpand(spa, spa->spa_root_vdev);
5626                 spa_config_exit(spa, SCL_CONFIG, FTAG);
5627         }
5628 
5629         /*
5630          * See if any devices need to be probed.
5631          */
5632         if (tasks & SPA_ASYNC_PROBE) {
5633                 spa_vdev_state_enter(spa, SCL_NONE);
5634                 spa_async_probe(spa, spa->spa_root_vdev);
5635                 (void) spa_vdev_state_exit(spa, NULL, 0);
5636         }
5637 
5638         /*
5639          * If any devices are done replacing, detach them.
5640          */
5641         if (tasks & SPA_ASYNC_RESILVER_DONE)
5642                 spa_vdev_resilver_done(spa);
5643 
5644         /*
5645          * Kick off a resilver.
5646          */
5647         if (tasks & SPA_ASYNC_RESILVER)
5648                 dsl_resilver_restart(spa->spa_dsl_pool, 0);
5649 
5650         /*
5651          * Let the world know that we're done.
5652          */
5653         mutex_enter(&spa->spa_async_lock);
5654         spa->spa_async_thread = NULL;
5655         cv_broadcast(&spa->spa_async_cv);
5656         mutex_exit(&spa->spa_async_lock);
5657         thread_exit();
5658 }
5659 
5660 void
5661 spa_async_suspend(spa_t *spa)
5662 {
5663         mutex_enter(&spa->spa_async_lock);
5664         spa->spa_async_suspended++;
5665         while (spa->spa_async_thread != NULL)
5666                 cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
5667         mutex_exit(&spa->spa_async_lock);
5668 }
5669 
5670 void
5671 spa_async_resume(spa_t *spa)
5672 {
5673         mutex_enter(&spa->spa_async_lock);
5674         ASSERT(spa->spa_async_suspended != 0);
5675         spa->spa_async_suspended--;
5676         mutex_exit(&spa->spa_async_lock);
5677 }
5678 
5679 static boolean_t
5680 spa_async_tasks_pending(spa_t *spa)
5681 {
5682         uint_t non_config_tasks;
5683         uint_t config_task;
5684         boolean_t config_task_suspended;
5685 
5686         non_config_tasks = spa->spa_async_tasks & ~SPA_ASYNC_CONFIG_UPDATE;
5687         config_task = spa->spa_async_tasks & SPA_ASYNC_CONFIG_UPDATE;
5688         if (spa->spa_ccw_fail_time == 0) {
5689                 config_task_suspended = B_FALSE;
5690         } else {
5691                 config_task_suspended =
5692                     (gethrtime() - spa->spa_ccw_fail_time) <
5693                     (zfs_ccw_retry_interval * NANOSEC);
5694         }
5695 
5696         return (non_config_tasks || (config_task && !config_task_suspended));
5697 }
5698 
5699 static void
5700 spa_async_dispatch(spa_t *spa)
5701 {
5702         mutex_enter(&spa->spa_async_lock);
5703         if (spa_async_tasks_pending(spa) &&
5704             !spa->spa_async_suspended &&
5705             spa->spa_async_thread == NULL &&
5706             rootdir != NULL)
5707                 spa->spa_async_thread = thread_create(NULL, 0,
5708                     spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
5709         mutex_exit(&spa->spa_async_lock);
5710 }
5711 
5712 void
5713 spa_async_request(spa_t *spa, int task)
5714 {
5715         zfs_dbgmsg("spa=%s async request task=%u", spa->spa_name, task);
5716         mutex_enter(&spa->spa_async_lock);
5717         spa->spa_async_tasks |= task;
5718         mutex_exit(&spa->spa_async_lock);
5719 }
5720 
5721 /*
5722  * ==========================================================================
5723  * SPA syncing routines
5724  * ==========================================================================
5725  */
5726 
5727 static int
5728 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5729 {
5730         bpobj_t *bpo = arg;
5731         bpobj_enqueue(bpo, bp, tx);
5732         return (0);
5733 }
5734 
5735 static int
5736 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5737 {
5738         zio_t *zio = arg;
5739 
5740         zio_nowait(zio_free_sync(zio, zio->io_spa, dmu_tx_get_txg(tx), bp,
5741             zio->io_flags));
5742         return (0);
5743 }
5744 
5745 static void
5746 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
5747 {
5748         char *packed = NULL;
5749         size_t bufsize;
5750         size_t nvsize = 0;
5751         dmu_buf_t *db;
5752 
5753         VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
5754 
5755         /*
5756          * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
5757          * information.  This avoids the dbuf_will_dirty() path and
5758          * saves us a pre-read to get data we don't actually care about.
5759          */
5760         bufsize = P2ROUNDUP((uint64_t)nvsize, SPA_CONFIG_BLOCKSIZE);
5761         packed = kmem_alloc(bufsize, KM_SLEEP);
5762 
5763         VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
5764             KM_SLEEP) == 0);
5765         bzero(packed + nvsize, bufsize - nvsize);
5766 
5767         dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
5768 
5769         kmem_free(packed, bufsize);
5770 
5771         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
5772         dmu_buf_will_dirty(db, tx);
5773         *(uint64_t *)db->db_data = nvsize;
5774         dmu_buf_rele(db, FTAG);
5775 }
5776 
5777 static void
5778 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
5779     const char *config, const char *entry)
5780 {
5781         nvlist_t *nvroot;
5782         nvlist_t **list;
5783         int i;
5784 
5785         if (!sav->sav_sync)
5786                 return;
5787 
5788         /*
5789          * Update the MOS nvlist describing the list of available devices.
5790          * spa_validate_aux() will have already made sure this nvlist is
5791          * valid and the vdevs are labeled appropriately.
5792          */
5793         if (sav->sav_object == 0) {
5794                 sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
5795                     DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
5796                     sizeof (uint64_t), tx);
5797                 VERIFY(zap_update(spa->spa_meta_objset,
5798                     DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
5799                     &sav->sav_object, tx) == 0);
5800         }
5801 
5802         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5803         if (sav->sav_count == 0) {
5804                 VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
5805         } else {
5806                 list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
5807                 for (i = 0; i < sav->sav_count; i++)
5808                         list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
5809                             B_FALSE, VDEV_CONFIG_L2CACHE);
5810                 VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
5811                     sav->sav_count) == 0);
5812                 for (i = 0; i < sav->sav_count; i++)
5813                         nvlist_free(list[i]);
5814                 kmem_free(list, sav->sav_count * sizeof (void *));
5815         }
5816 
5817         spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
5818         nvlist_free(nvroot);
5819 
5820         sav->sav_sync = B_FALSE;
5821 }
5822 
5823 static void
5824 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
5825 {
5826         nvlist_t *config;
5827 
5828         if (list_is_empty(&spa->spa_config_dirty_list))
5829                 return;
5830 
5831         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5832 
5833         config = spa_config_generate(spa, spa->spa_root_vdev,
5834             dmu_tx_get_txg(tx), B_FALSE);
5835 
5836         /*
5837          * If we're upgrading the spa version then make sure that
5838          * the config object gets updated with the correct version.
5839          */
5840         if (spa->spa_ubsync.ub_version < spa->spa_uberblock.ub_version)
5841                 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
5842                     spa->spa_uberblock.ub_version);
5843 
5844         spa_config_exit(spa, SCL_STATE, FTAG);
5845 
5846         if (spa->spa_config_syncing)
5847                 nvlist_free(spa->spa_config_syncing);
5848         spa->spa_config_syncing = config;
5849 
5850         spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
5851 }
5852 
5853 static void
5854 spa_sync_version(void *arg, dmu_tx_t *tx)
5855 {
5856         uint64_t *versionp = arg;
5857         uint64_t version = *versionp;
5858         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5859 
5860         /*
5861          * Setting the version is special cased when first creating the pool.
5862          */
5863         ASSERT(tx->tx_txg != TXG_INITIAL);
5864 
5865         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
5866         ASSERT(version >= spa_version(spa));
5867 
5868         spa->spa_uberblock.ub_version = version;
5869         vdev_config_dirty(spa->spa_root_vdev);
5870         spa_history_log_internal(spa, "set", tx, "version=%lld", version);
5871 }
5872 
5873 /*
5874  * Set zpool properties.
5875  */
5876 static void
5877 spa_sync_props(void *arg, dmu_tx_t *tx)
5878 {
5879         nvlist_t *nvp = arg;
5880         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5881         objset_t *mos = spa->spa_meta_objset;
5882         nvpair_t *elem = NULL;
5883 
5884         mutex_enter(&spa->spa_props_lock);
5885 
5886         while ((elem = nvlist_next_nvpair(nvp, elem))) {
5887                 uint64_t intval;
5888                 char *strval, *fname;
5889                 zpool_prop_t prop;
5890                 const char *propname;
5891                 zprop_type_t proptype;
5892                 zfeature_info_t *feature;
5893 
5894                 switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
5895                 case ZPROP_INVAL:
5896                         /*
5897                          * We checked this earlier in spa_prop_validate().
5898                          */
5899                         ASSERT(zpool_prop_feature(nvpair_name(elem)));
5900 
5901                         fname = strchr(nvpair_name(elem), '@') + 1;
5902                         VERIFY3U(0, ==, zfeature_lookup_name(fname, &feature));
5903 
5904                         spa_feature_enable(spa, feature, tx);
5905                         spa_history_log_internal(spa, "set", tx,
5906                             "%s=enabled", nvpair_name(elem));
5907                         break;
5908 
5909                 case ZPOOL_PROP_VERSION:
5910                         VERIFY(nvpair_value_uint64(elem, &intval) == 0);
5911                         /*
5912                          * The version is synced seperatly before other
5913                          * properties and should be correct by now.
5914                          */
5915                         ASSERT3U(spa_version(spa), >=, intval);
5916                         break;
5917 
5918                 case ZPOOL_PROP_ALTROOT:
5919                         /*
5920                          * 'altroot' is a non-persistent property. It should
5921                          * have been set temporarily at creation or import time.
5922                          */
5923                         ASSERT(spa->spa_root != NULL);
5924                         break;
5925 
5926                 case ZPOOL_PROP_READONLY:
5927                 case ZPOOL_PROP_CACHEFILE:
5928                         /*
5929                          * 'readonly' and 'cachefile' are also non-persisitent
5930                          * properties.
5931                          */
5932                         break;
5933                 case ZPOOL_PROP_COMMENT:
5934                         VERIFY(nvpair_value_string(elem, &strval) == 0);
5935                         if (spa->spa_comment != NULL)
5936                                 spa_strfree(spa->spa_comment);
5937                         spa->spa_comment = spa_strdup(strval);
5938                         /*
5939                          * We need to dirty the configuration on all the vdevs
5940                          * so that their labels get updated.  It's unnecessary
5941                          * to do this for pool creation since the vdev's
5942                          * configuratoin has already been dirtied.
5943                          */
5944                         if (tx->tx_txg != TXG_INITIAL)
5945                                 vdev_config_dirty(spa->spa_root_vdev);
5946                         spa_history_log_internal(spa, "set", tx,
5947                             "%s=%s", nvpair_name(elem), strval);
5948                         break;
5949                 default:
5950                         /*
5951                          * Set pool property values in the poolprops mos object.
5952                          */
5953                         if (spa->spa_pool_props_object == 0) {
5954                                 spa->spa_pool_props_object =
5955                                     zap_create_link(mos, DMU_OT_POOL_PROPS,
5956                                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
5957                                     tx);
5958                         }
5959 
5960                         /* normalize the property name */
5961                         propname = zpool_prop_to_name(prop);
5962                         proptype = zpool_prop_get_type(prop);
5963 
5964                         if (nvpair_type(elem) == DATA_TYPE_STRING) {
5965                                 ASSERT(proptype == PROP_TYPE_STRING);
5966                                 VERIFY(nvpair_value_string(elem, &strval) == 0);
5967                                 VERIFY(zap_update(mos,
5968                                     spa->spa_pool_props_object, propname,
5969                                     1, strlen(strval) + 1, strval, tx) == 0);
5970                                 spa_history_log_internal(spa, "set", tx,
5971                                     "%s=%s", nvpair_name(elem), strval);
5972                         } else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
5973                                 VERIFY(nvpair_value_uint64(elem, &intval) == 0);
5974 
5975                                 if (proptype == PROP_TYPE_INDEX) {
5976                                         const char *unused;
5977                                         VERIFY(zpool_prop_index_to_string(
5978                                             prop, intval, &unused) == 0);
5979                                 }
5980                                 VERIFY(zap_update(mos,
5981                                     spa->spa_pool_props_object, propname,
5982                                     8, 1, &intval, tx) == 0);
5983                                 spa_history_log_internal(spa, "set", tx,
5984                                     "%s=%lld", nvpair_name(elem), intval);
5985                         } else {
5986                                 ASSERT(0); /* not allowed */
5987                         }
5988 
5989                         switch (prop) {
5990                         case ZPOOL_PROP_DELEGATION:
5991                                 spa->spa_delegation = intval;
5992                                 break;
5993                         case ZPOOL_PROP_BOOTFS:
5994                                 spa->spa_bootfs = intval;
5995                                 break;
5996                         case ZPOOL_PROP_FAILUREMODE:
5997                                 spa->spa_failmode = intval;
5998                                 break;
5999                         case ZPOOL_PROP_AUTOEXPAND:
6000                                 spa->spa_autoexpand = intval;
6001                                 if (tx->tx_txg != TXG_INITIAL)
6002                                         spa_async_request(spa,
6003                                             SPA_ASYNC_AUTOEXPAND);
6004                                 break;
6005                         case ZPOOL_PROP_DEDUPDITTO:
6006                                 spa->spa_dedup_ditto = intval;
6007                                 break;
6008                         default:
6009                                 break;
6010                         }
6011                 }
6012 
6013         }
6014 
6015         mutex_exit(&spa->spa_props_lock);
6016 }
6017 
6018 /*
6019  * Perform one-time upgrade on-disk changes.  spa_version() does not
6020  * reflect the new version this txg, so there must be no changes this
6021  * txg to anything that the upgrade code depends on after it executes.
6022  * Therefore this must be called after dsl_pool_sync() does the sync
6023  * tasks.
6024  */
6025 static void
6026 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
6027 {
6028         dsl_pool_t *dp = spa->spa_dsl_pool;
6029 
6030         ASSERT(spa->spa_sync_pass == 1);
6031 
6032         rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
6033 
6034         if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
6035             spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
6036                 dsl_pool_create_origin(dp, tx);
6037 
6038                 /* Keeping the origin open increases spa_minref */
6039                 spa->spa_minref += 3;
6040         }
6041 
6042         if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
6043             spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
6044                 dsl_pool_upgrade_clones(dp, tx);
6045         }
6046 
6047         if (spa->spa_ubsync.ub_version < SPA_VERSION_DIR_CLONES &&
6048             spa->spa_uberblock.ub_version >= SPA_VERSION_DIR_CLONES) {
6049                 dsl_pool_upgrade_dir_clones(dp, tx);
6050 
6051                 /* Keeping the freedir open increases spa_minref */
6052                 spa->spa_minref += 3;
6053         }
6054 
6055         if (spa->spa_ubsync.ub_version < SPA_VERSION_FEATURES &&
6056             spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
6057                 spa_feature_create_zap_objects(spa, tx);
6058         }
6059         rrw_exit(&dp->dp_config_rwlock, FTAG);
6060 }
6061 
6062 /*
6063  * Sync the specified transaction group.  New blocks may be dirtied as
6064  * part of the process, so we iterate until it converges.
6065  */
6066 void
6067 spa_sync(spa_t *spa, uint64_t txg)
6068 {
6069         dsl_pool_t *dp = spa->spa_dsl_pool;
6070         objset_t *mos = spa->spa_meta_objset;
6071         bpobj_t *defer_bpo = &spa->spa_deferred_bpobj;
6072         bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
6073         vdev_t *rvd = spa->spa_root_vdev;
6074         vdev_t *vd;
6075         dmu_tx_t *tx;
6076         int error;
6077 
6078         VERIFY(spa_writeable(spa));
6079 
6080         /*
6081          * Lock out configuration changes.
6082          */
6083         spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
6084 
6085         spa->spa_syncing_txg = txg;
6086         spa->spa_sync_pass = 0;
6087 
6088         /*
6089          * If there are any pending vdev state changes, convert them
6090          * into config changes that go out with this transaction group.
6091          */
6092         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6093         while (list_head(&spa->spa_state_dirty_list) != NULL) {
6094                 /*
6095                  * We need the write lock here because, for aux vdevs,
6096                  * calling vdev_config_dirty() modifies sav_config.
6097                  * This is ugly and will become unnecessary when we
6098                  * eliminate the aux vdev wart by integrating all vdevs
6099                  * into the root vdev tree.
6100                  */
6101                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6102                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
6103                 while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
6104                         vdev_state_clean(vd);
6105                         vdev_config_dirty(vd);
6106                 }
6107                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6108                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
6109         }
6110         spa_config_exit(spa, SCL_STATE, FTAG);
6111 
6112         tx = dmu_tx_create_assigned(dp, txg);
6113 
6114         spa->spa_sync_starttime = gethrtime();
6115         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid,
6116             spa->spa_sync_starttime + spa->spa_deadman_synctime));
6117 
6118         /*
6119          * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
6120          * set spa_deflate if we have no raid-z vdevs.
6121          */
6122         if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
6123             spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
6124                 int i;
6125 
6126                 for (i = 0; i < rvd->vdev_children; i++) {
6127                         vd = rvd->vdev_child[i];
6128                         if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
6129                                 break;
6130                 }
6131                 if (i == rvd->vdev_children) {
6132                         spa->spa_deflate = TRUE;
6133                         VERIFY(0 == zap_add(spa->spa_meta_objset,
6134                             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
6135                             sizeof (uint64_t), 1, &spa->spa_deflate, tx));
6136                 }
6137         }
6138 
6139         /*
6140          * If anything has changed in this txg, or if someone is waiting
6141          * for this txg to sync (eg, spa_vdev_remove()), push the
6142          * deferred frees from the previous txg.  If not, leave them
6143          * alone so that we don't generate work on an otherwise idle
6144          * system.
6145          */
6146         if (!txg_list_empty(&dp->dp_dirty_datasets, txg) ||
6147             !txg_list_empty(&dp->dp_dirty_dirs, txg) ||
6148             !txg_list_empty(&dp->dp_sync_tasks, txg) ||
6149             ((dsl_scan_active(dp->dp_scan) ||
6150             txg_sync_waiting(dp)) && !spa_shutting_down(spa))) {
6151                 zio_t *zio = zio_root(spa, NULL, NULL, 0);
6152                 VERIFY3U(bpobj_iterate(defer_bpo,
6153                     spa_free_sync_cb, zio, tx), ==, 0);
6154                 VERIFY0(zio_wait(zio));
6155         }
6156 
6157         /*
6158          * Iterate to convergence.
6159          */
6160         do {
6161                 int pass = ++spa->spa_sync_pass;
6162 
6163                 spa_sync_config_object(spa, tx);
6164                 spa_sync_aux_dev(spa, &spa->spa_spares, tx,
6165                     ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
6166                 spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
6167                     ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
6168                 spa_errlog_sync(spa, txg);
6169                 dsl_pool_sync(dp, txg);
6170 
6171                 if (pass < zfs_sync_pass_deferred_free) {
6172                         zio_t *zio = zio_root(spa, NULL, NULL, 0);
6173                         bplist_iterate(free_bpl, spa_free_sync_cb,
6174                             zio, tx);
6175                         VERIFY(zio_wait(zio) == 0);
6176                 } else {
6177                         bplist_iterate(free_bpl, bpobj_enqueue_cb,
6178                             defer_bpo, tx);
6179                 }
6180 
6181                 ddt_sync(spa, txg);
6182                 dsl_scan_sync(dp, tx);
6183 
6184                 while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
6185                         vdev_sync(vd, txg);
6186 
6187                 if (pass == 1)
6188                         spa_sync_upgrades(spa, tx);
6189 
6190         } while (dmu_objset_is_dirty(mos, txg));
6191 
6192         /*
6193          * Rewrite the vdev configuration (which includes the uberblock)
6194          * to commit the transaction group.
6195          *
6196          * If there are no dirty vdevs, we sync the uberblock to a few
6197          * random top-level vdevs that are known to be visible in the
6198          * config cache (see spa_vdev_add() for a complete description).
6199          * If there *are* dirty vdevs, sync the uberblock to all vdevs.
6200          */
6201         for (;;) {
6202                 /*
6203                  * We hold SCL_STATE to prevent vdev open/close/etc.
6204                  * while we're attempting to write the vdev labels.
6205                  */
6206                 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6207 
6208                 if (list_is_empty(&spa->spa_config_dirty_list)) {
6209                         vdev_t *svd[SPA_DVAS_PER_BP];
6210                         int svdcount = 0;
6211                         int children = rvd->vdev_children;
6212                         int c0 = spa_get_random(children);
6213 
6214                         for (int c = 0; c < children; c++) {
6215                                 vd = rvd->vdev_child[(c0 + c) % children];
6216                                 if (vd->vdev_ms_array == 0 || vd->vdev_islog)
6217                                         continue;
6218                                 svd[svdcount++] = vd;
6219                                 if (svdcount == SPA_DVAS_PER_BP)
6220                                         break;
6221                         }
6222                         error = vdev_config_sync(svd, svdcount, txg, B_FALSE);
6223                         if (error != 0)
6224                                 error = vdev_config_sync(svd, svdcount, txg,
6225                                     B_TRUE);
6226                 } else {
6227                         error = vdev_config_sync(rvd->vdev_child,
6228                             rvd->vdev_children, txg, B_FALSE);
6229                         if (error != 0)
6230                                 error = vdev_config_sync(rvd->vdev_child,
6231                                     rvd->vdev_children, txg, B_TRUE);
6232                 }
6233 
6234                 if (error == 0)
6235                         spa->spa_last_synced_guid = rvd->vdev_guid;
6236 
6237                 spa_config_exit(spa, SCL_STATE, FTAG);
6238 
6239                 if (error == 0)
6240                         break;
6241                 zio_suspend(spa, NULL);
6242                 zio_resume_wait(spa);
6243         }
6244         dmu_tx_commit(tx);
6245 
6246         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
6247 
6248         /*
6249          * Clear the dirty config list.
6250          */
6251         while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
6252                 vdev_config_clean(vd);
6253 
6254         /*
6255          * Now that the new config has synced transactionally,
6256          * let it become visible to the config cache.
6257          */
6258         if (spa->spa_config_syncing != NULL) {
6259                 spa_config_set(spa, spa->spa_config_syncing);
6260                 spa->spa_config_txg = txg;
6261                 spa->spa_config_syncing = NULL;
6262         }
6263 
6264         spa->spa_ubsync = spa->spa_uberblock;
6265 
6266         dsl_pool_sync_done(dp, txg);
6267 
6268         /*
6269          * Update usable space statistics.
6270          */
6271         while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
6272                 vdev_sync_done(vd, txg);
6273 
6274         spa_update_dspace(spa);
6275 
6276         /*
6277          * It had better be the case that we didn't dirty anything
6278          * since vdev_config_sync().
6279          */
6280         ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
6281         ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
6282         ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
6283 
6284         spa->spa_sync_pass = 0;
6285 
6286         spa_config_exit(spa, SCL_CONFIG, FTAG);
6287 
6288         spa_handle_ignored_writes(spa);
6289 
6290         /*
6291          * If any async tasks have been requested, kick them off.
6292          */
6293         spa_async_dispatch(spa);
6294 }
6295 
6296 /*
6297  * Sync all pools.  We don't want to hold the namespace lock across these
6298  * operations, so we take a reference on the spa_t and drop the lock during the
6299  * sync.
6300  */
6301 void
6302 spa_sync_allpools(void)
6303 {
6304         spa_t *spa = NULL;
6305         mutex_enter(&spa_namespace_lock);
6306         while ((spa = spa_next(spa)) != NULL) {
6307                 if (spa_state(spa) != POOL_STATE_ACTIVE ||
6308                     !spa_writeable(spa) || spa_suspended(spa))
6309                         continue;
6310                 spa_open_ref(spa, FTAG);
6311                 mutex_exit(&spa_namespace_lock);
6312                 txg_wait_synced(spa_get_dsl(spa), 0);
6313                 mutex_enter(&spa_namespace_lock);
6314                 spa_close(spa, FTAG);
6315         }
6316         mutex_exit(&spa_namespace_lock);
6317 }
6318 
6319 /*
6320  * ==========================================================================
6321  * Miscellaneous routines
6322  * ==========================================================================
6323  */
6324 
6325 /*
6326  * Remove all pools in the system.
6327  */
6328 void
6329 spa_evict_all(void)
6330 {
6331         spa_t *spa;
6332 
6333         /*
6334          * Remove all cached state.  All pools should be closed now,
6335          * so every spa in the AVL tree should be unreferenced.
6336          */
6337         mutex_enter(&spa_namespace_lock);
6338         while ((spa = spa_next(NULL)) != NULL) {
6339                 /*
6340                  * Stop async tasks.  The async thread may need to detach
6341                  * a device that's been replaced, which requires grabbing
6342                  * spa_namespace_lock, so we must drop it here.
6343                  */
6344                 spa_open_ref(spa, FTAG);
6345                 mutex_exit(&spa_namespace_lock);
6346                 spa_async_suspend(spa);
6347                 mutex_enter(&spa_namespace_lock);
6348                 spa_close(spa, FTAG);
6349 
6350                 if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
6351                         spa_unload(spa);
6352                         spa_deactivate(spa);
6353                 }
6354                 spa_remove(spa);
6355         }
6356         mutex_exit(&spa_namespace_lock);
6357 }
6358 
6359 vdev_t *
6360 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
6361 {
6362         vdev_t *vd;
6363         int i;
6364 
6365         if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
6366                 return (vd);
6367 
6368         if (aux) {
6369                 for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
6370                         vd = spa->spa_l2cache.sav_vdevs[i];
6371                         if (vd->vdev_guid == guid)
6372                                 return (vd);
6373                 }
6374 
6375                 for (i = 0; i < spa->spa_spares.sav_count; i++) {
6376                         vd = spa->spa_spares.sav_vdevs[i];
6377                         if (vd->vdev_guid == guid)
6378                                 return (vd);
6379                 }
6380         }
6381 
6382         return (NULL);
6383 }
6384 
6385 void
6386 spa_upgrade(spa_t *spa, uint64_t version)
6387 {
6388         ASSERT(spa_writeable(spa));
6389 
6390         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6391 
6392         /*
6393          * This should only be called for a non-faulted pool, and since a
6394          * future version would result in an unopenable pool, this shouldn't be
6395          * possible.
6396          */
6397         ASSERT(SPA_VERSION_IS_SUPPORTED(spa->spa_uberblock.ub_version));
6398         ASSERT(version >= spa->spa_uberblock.ub_version);
6399 
6400         spa->spa_uberblock.ub_version = version;
6401         vdev_config_dirty(spa->spa_root_vdev);
6402 
6403         spa_config_exit(spa, SCL_ALL, FTAG);
6404 
6405         txg_wait_synced(spa_get_dsl(spa), 0);
6406 }
6407 
6408 boolean_t
6409 spa_has_spare(spa_t *spa, uint64_t guid)
6410 {
6411         int i;
6412         uint64_t spareguid;
6413         spa_aux_vdev_t *sav = &spa->spa_spares;
6414 
6415         for (i = 0; i < sav->sav_count; i++)
6416                 if (sav->sav_vdevs[i]->vdev_guid == guid)
6417                         return (B_TRUE);
6418 
6419         for (i = 0; i < sav->sav_npending; i++) {
6420                 if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
6421                     &spareguid) == 0 && spareguid == guid)
6422                         return (B_TRUE);
6423         }
6424 
6425         return (B_FALSE);
6426 }
6427 
6428 /*
6429  * Check if a pool has an active shared spare device.
6430  * Note: reference count of an active spare is 2, as a spare and as a replace
6431  */
6432 static boolean_t
6433 spa_has_active_shared_spare(spa_t *spa)
6434 {
6435         int i, refcnt;
6436         uint64_t pool;
6437         spa_aux_vdev_t *sav = &spa->spa_spares;
6438 
6439         for (i = 0; i < sav->sav_count; i++) {
6440                 if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
6441                     &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
6442                     refcnt > 2)
6443                         return (B_TRUE);
6444         }
6445 
6446         return (B_FALSE);
6447 }
6448 
6449 /*
6450  * Post a sysevent corresponding to the given event.  The 'name' must be one of
6451  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
6452  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
6453  * in the userland libzpool, as we don't want consumers to misinterpret ztest
6454  * or zdb as real changes.
6455  */
6456 void
6457 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
6458 {
6459 #ifdef _KERNEL
6460         sysevent_t              *ev;
6461         sysevent_attr_list_t    *attr = NULL;
6462         sysevent_value_t        value;
6463         sysevent_id_t           eid;
6464 
6465         ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
6466             SE_SLEEP);
6467 
6468         value.value_type = SE_DATA_TYPE_STRING;
6469         value.value.sv_string = spa_name(spa);
6470         if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
6471                 goto done;
6472 
6473         value.value_type = SE_DATA_TYPE_UINT64;
6474         value.value.sv_uint64 = spa_guid(spa);
6475         if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
6476                 goto done;
6477 
6478         if (vd) {
6479                 value.value_type = SE_DATA_TYPE_UINT64;
6480                 value.value.sv_uint64 = vd->vdev_guid;
6481                 if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
6482                     SE_SLEEP) != 0)
6483                         goto done;
6484 
6485                 if (vd->vdev_path) {
6486                         value.value_type = SE_DATA_TYPE_STRING;
6487                         value.value.sv_string = vd->vdev_path;
6488                         if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
6489                             &value, SE_SLEEP) != 0)
6490                                 goto done;
6491                 }
6492         }
6493 
6494         if (sysevent_attach_attributes(ev, attr) != 0)
6495                 goto done;
6496         attr = NULL;
6497 
6498         (void) log_sysevent(ev, SE_SLEEP, &eid);
6499 
6500 done:
6501         if (attr)
6502                 sysevent_free_attr(attr);
6503         sysevent_free(ev);
6504 #endif
6505 }